Use of radiography, computed tomography and magnetic resonance imaging for evaluation of navicular syndrome in the horse.

PubMed

Widmer, W R; Buckwalter, K A; Fessler, J F; Hill, M A; VanSickle, D C; Ivancevich, S

2000-01-01

Radiographic evaluation of navicular syndrome is problematic because of its inconsistent correlation with clinical signs. Scintigraphy often yields false positive and false negative results and diagnostic ultrasound is of limited value. Therefore, we assessed the use of computed tomography and magnetic resonance imaging in a horse with clinical and radiographic signs of navicular syndrome. Cadaver specimens were examined with spiral computed tomographic and high-field magnetic resonance scanners and images were correlated with pathologic findings. Radiographic changes consisted of bony remodeling, which included altered synovial fossae, increased medullary opacity, cyst formation and shape change. These osseous changes were more striking and more numerous on computed tomographic and magnetic resonance images. They were most clearly defined with computed tomography. Many osseous changes seen with computed tomography and magnetic resonance imaging were not radiographically evident. Histologically confirmed soft tissue alterations of the deep digital flexor tendon, impar ligament and marrow were identified with magnetic resonance imaging, but not with conventional radiography. Because of their multiplanar capability and tomographic nature, computed tomography and magnetic resonance imaging surpass conventional radiography for navicular imaging, facilitating earlier, more accurate diagnosis. Current advances in imaging technology should make these imaging modalities available to equine practitioners in the future.

Multiplanar visualization in 3D transthoracic echocardiography for precise delineation of mitral valve pathology.

PubMed

Kuppahally, Suman S; Paloma, Allan; Craig Miller, D; Schnittger, Ingela; Liang, David

2008-01-01

A novel multiplanar reformatting (MPR) technique in three-dimensional transthoracic echocardiography (3D TTE) was used to precisely localize the prolapsed lateral segment of posterior mitral valve leaflet in a patient symptomatic with mitral valve prolapse (MVP) and moderate mitral regurgitation (MR) before undergoing mitral valve repair surgery. Transesophageal echocardiography was avoided based on the findings of this new technique by 3D TTE. It was noninvasive, quick, reproducible and reliable. Also, it did not need the time-consuming reconstruction of multiple cardiac images. Mitral valve repair surgery was subsequently performed based on the MPR findings and corroborated the findings from the MPR examination.

Lumbar spinal stenosis CAD from clinical MRM and MRI based on inter- and intra-context features with a two-level classifier

NASA Astrophysics Data System (ADS)

Koh, Jaehan; Alomari, Raja S.; Chaudhary, Vipin; Dhillon, Gurmeet

2011-03-01

An imaging test has an important role in the diagnosis of lumbar abnormalities since it allows to examine the internal structure of soft tissues and bony elements without the need of an unnecessary surgery and recovery time. For the past decade, among various imaging modalities, magnetic resonance imaging (MRI) has taken the significant part of the clinical evaluation of the lumbar spine. This is mainly due to technological advancements that lead to the improvement of imaging devices in spatial resolution, contrast resolution, and multi-planar capabilities. In addition, noninvasive nature of MRI makes it easy to diagnose many common causes of low back pain such as disc herniation, spinal stenosis, and degenerative disc diseases. In this paper, we propose a method to diagnose lumbar spinal stenosis (LSS), a narrowing of the spinal canal, from magnetic resonance myelography (MRM) images. Our method segments the thecal sac in the preprocessing stage, generates the features based on inter- and intra-context information, and diagnoses lumbar disc stenosis. Experiments with 55 subjects show that our method achieves 91.3% diagnostic accuracy. In the future, we plan to test our method on more subjects.

Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging.

PubMed

Homsi, R; Gieseke, J; Luetkens, J A; Kupczyk, P; Maedler, B; Kukuk, G M; Träber, F; Agha, B; Rauch, M; Rajakaruna, N; Willinek, W; Schild, H H; Hadizadeh, D R

2016-10-01

To evaluate whether a 3 D proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS. 52 patients (26 men, mean age: 41.9 ± 14.5years) underwent magnetic resonance imaging (MRI) of the knee at 3.0 Tesla using a T/R-coil. The imaging protocol included 3 planes of 2D-PDwFS (acquisition time (AT): 6:40 min; voxel sizes: 0.40 - 0.63 × 0.44 - 0.89 × 3mm³) and a 3D-PDwFS (AT: 6:31 min; voxel size: 0.63 × 0.68 × 0.63mm³). Homogeneity of fat suppression (HFS), artifacts, and image sharpness (IS) were evaluated on a 5-point scale (5[excellent] - 1[non-diagnostic]). The sum served as a measure for the overall image quality (OIQ). Contrast ratios (CR) compared to popliteal muscle were calculated for the meniscus (MEN), anterior (ACL) and posterior cruciate ligaments (PCL). In 13 patients who underwent arthroscopic knee surgery, two radiologists evaluated the presence of meniscal, ligamental and cartilage lesions to estimate the sensitivity and specificity of lesion detection. The CR was higher in the ACL, PCL and MEN in 3D- PDwFS compared to 2D-PDwFS (p < 0.01 for ACL and PCL; p = 0.07 for MEN). Compared to 2 D images, the OIQ was rated higher in 3D-PDwFS images (p < 0.01) due to fewer artifacts and HFS despite the lower IS (p < 0.01). The sensitivity and specificity of lesion detection in 3D- and 2D-PDwFS were similar. Compared to standard multiplanar 2D-PDwFS knee imaging, isotropic high spatial resolution 3D-PDwFS of the knee at 3.0 T can be acquired with high image quality in a reasonable scan time. Multiplanar reformations in arbitrary planes may serve as an additional benefit of 3D-PDwFS. • 3D-PDwFS of the knee is acquired with high image quality• 3D-PDwFS can be achieved in only one measurement with a reasonable scan time• 3D-PDwFS with the advantage of multiplanar reformation may replace 2D-PD-weighted knee MRI Citation Format: • Homsi R, Gieseke J, Luetkens JA et al. Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging. Fortschr Röntgenstr 2016; 188: 949 - 956. © Georg Thieme Verlag KG Stuttgart · New York.

Diagnostic imaging in uterine incisional necrosis/dehiscence complicating cesarean section.

PubMed

Rivlin, Michel E; Patel, Rameshkumar B; Carroll, C Shannon; Morrison, John C

2005-12-01

To review the diagnostic imaging studies in patients with surgically proven uterine incisional necrosis/dehiscence complicating cesarean section and to compare these studies with the findings at surgery. Over a 6-year period, the records of 7 patients with imaging studies prior to surgery for uterine incisional necrosis/dehiscence complicating cesarean delivery were reviewed and compared with the findings at surgery. Four cases underwent computed tomography (CT) and sonography, 1 underwent CT only, and 2 underwent sonography only. Abnormal findings included abdominal free fluid in 4, pleural effusions in 3, dilated bowel in 3, possible bladder flap hematoma in 2 and single instances of liver abscess and retained products of conception. In no cases were all the studies normal, and necrosis/dehiscence was not demonstrated in any patient. Abdominal free fluid, bowel distension, pleural effusion and bladder flap hematoma seen on CT or sonogram in the postcesarean context suggest the possibility of uterine incisional necrosis/dehiscence. Magnetic resonance imaging (MRI) might then be indicated since MRI may be superior to CT in evaluating complications at the incisional site because of its multiplanar capability and greater degree of soft tissue contrast.

64-MDCT angiography of blunt vascular injuries of the neck.

PubMed

Chokshi, Falgun H; Munera, Felipe; Rivas, Luis A; Henry, Robert P; Quencer, Robert M

2011-03-01

CT angiography (CTA) using 64-MDCT enables timely evaluation of injuries associated with blunt neck trauma. The purpose of this article is to familiarize the reader with the most frequent CTA signs of blunt vascular injury. CTA is a valuable tool to detect blunt vascular injuries, especially using its multiplanar and 3D reconstruction capabilities.

Pediatric head and neck masses.

PubMed

Gujar, Sachin; Gandhi, Dheeraj; Mukherji, Suresh K

2004-04-01

Most neck masses in the pediatric head and neck region are benign. Congenital, developmental, and inflammatory lesions make up most of the masses in the pediatric head and neck. For example, neck masses due to inflammatory lymphadenitis are common in children because of the frequency of upper respiratory tract infections. Although many of the malignant tumors in children are found in the head and neck, they account for only a small portion of the neck masses. The choice of the imaging modality is based on a number of factors, several of which are unique to the pediatric population. Although the bulk of disease entities are adequately evaluated by CT, MRI can provide additional vital information in many cases. MRI provides better soft tissue characterization than CT, has multiplanar capabilities. In this article, we will attempt to provide an overview of conditions that present as neck masses.

Four-dimensional ultrasonography of the fetal heart with spatiotemporal image correlation.

PubMed

Gonçalves, Luís F; Lee, Wesley; Chaiworapongsa, Tinnakorn; Espinoza, Jimmy; Schoen, Mary Lou; Falkensammer, Peter; Treadwell, Marjorie; Romero, Roberto

2003-12-01

This study was undertaken to describe a new technique for the examination of the fetal heart using four-dimensional ultrasonography with spatiotemporal image correlation (STIC). Volume data sets of the fetal heart were acquired with a new cardiac gating technique (STIC), which uses automated transverse and longitudinal sweeps of the anterior chest wall. These volumes were obtained from 69 fetuses: 35 normal, 16 with congenital anomalies not affecting the cardiovascular system, and 18 with cardiac abnormalities. Dynamic multiplanar slicing and surface rendering of cardiac structures were performed. To illustrate the STIC technique, two representative volumes from a normal fetus were compared with volumes obtained from fetuses with the following congenital heart anomalies: atrioventricular septal defect, tricuspid stenosis, tricuspid atresia, and interrupted inferior vena cava with abnormal venous drainage. Volume datasets obtained with a transverse sweep were utilized to demonstrate the cardiac chambers, moderator band, interatrial and interventricular septae, atrioventricular valves, pulmonary veins, and outflow tracts. With the use of a reference dot to navigate the four-chamber view, intracardiac structures could be simultaneously studied in three orthogonal planes. The same volume dataset was used for surface rendering of the atrioventricular valves. The aortic and ductal arches were best visualized when the original plane of acquisition was sagittal. Volumes could be interactively manipulated to simultaneously visualize both outflow tracts, in addition to the aortic and ductal arches. Novel views of specific structures were generated. For example, the location and extent of a ventricular septal defect was imaged in a sagittal view of the interventricular septum. Furthermore, surface-rendered images of the atrioventricular valves were employed to distinguish between normal and pathologic conditions. Representative video clips were posted on the Journal's Web site to demonstrate the diagnostic capabilities of this new technique. Dynamic multiplanar slicing and surface rendering of the fetal heart are feasible with STIC technology. One good quality volume dataset, obtained from a transverse sweep, can be used to examine the four-chamber view and the outflow tracts. This novel method may assist in the evaluation of fetal cardiac anatomy.

New-Generation Laser-lithographed Dual-Axis Magnetically Assisted Remote-controlled Endovascular Catheter for Interventional MR Imaging: In Vitro Multiplanar Navigation at 1.5 T and 3 T versus X-ray Fluoroscopy.

PubMed

Moftakhar, Parham; Lillaney, Prasheel; Losey, Aaron D; Cooke, Daniel L; Martin, Alastair J; Thorne, Bradford R H; Arenson, Ronald L; Saeed, Maythem; Wilson, Mark W; Hetts, Steven W

2015-12-01

To assess the feasibility of multiplanar vascular navigation with a new magnetically assisted remote-controlled (MARC) catheter with real-time magnetic resonance (MR) imaging at 1.5 T and 3 T and to compare it with standard x-ray guidance in simulated endovascular catheterization procedures. A 1.6-mm-diameter custom clinical-grade microcatheter prototype with lithographed double-saddle coils at the distal tip was deflected with real-time MR imaging. Two inexperienced operators and two experienced operators catheterized anteroposterior (celiac, superior mesenteric, and inferior mesenteric arteries) and mediolateral (renal arteries) branch vessels in a cryogel abdominal aortic phantom. This was repeated with conventional x-ray fluoroscopy by using clinical catheters and guidewires. Mean procedure times and percentage success data were analyzed with linear mixed-effects regression. The MARC catheter tip was visible at 1.5 T and 3 T. Among inexperienced operators, MARC MR imaging guidance was not statistically different from x-ray guidance at 1.5 T (67% successful vessel selection turns with MR imaging vs 76% with x-ray guidance, P = .157) and at 3 T (75% successful turns with MR imaging vs 76% with x-ray guidance, P = .869). Experienced operators were more successful in catheterizing vessels with x-ray guidance (98% success within 60 seconds) than with 1.5-T (65%, P < .001) or 3-T (75%) MR imaging. Among inexperienced operators, mean procedure time was nearly equivalent by using MR imaging (31 seconds) and x-ray guidance (34 seconds, P = .436). Among experienced operators, catheterization was faster with x-ray guidance (20 seconds) compared with 1.5-T MR imaging (42 seconds, P < .001), but MARC guidance improved at 3 T (31 seconds). MARC MR imaging guidance at 3 T was not significantly different from x-ray guidance for the celiac (P = .755), superior mesenteric (P = .358), and inferior mesenteric (P = .065) arteries. Multiplanar navigation with a new MARC catheter with real-time MR imaging at 1.5 T and 3 T is feasible and comparable to x-ray guidance for anteroposterior vessels at 3 T in a vascular phantom.

New-Generation Laser-lithographed Dual-Axis Magnetically Assisted Remote-controlled Endovascular Catheter for Interventional MR Imaging: In Vitro Multiplanar Navigation at 1.5 T and 3 T versus X-ray Fluoroscopy

PubMed Central

Moftakhar, Parham; Lillaney, Prasheel; Losey, Aaron D.; Cooke, Daniel L.; Martin, Alastair J.; Thorne, Bradford R. H.; Arenson, Ronald L.; Saeed, Maythem; Wilson, Mark W.

2015-01-01

Purpose To assess the feasibility of multiplanar vascular navigation with a new magnetically assisted remote-controlled (MARC) catheter with real-time magnetic resonance (MR) imaging at 1.5 T and 3 T and to compare it with standard x-ray guidance in simulated endovascular catheterization procedures. Materials and Methods A 1.6-mm–diameter custom clinical-grade microcatheter prototype with lithographed double-saddle coils at the distal tip was deflected with real-time MR imaging. Two inexperienced operators and two experienced operators catheterized anteroposterior (celiac, superior mesenteric, and inferior mesenteric arteries) and mediolateral (renal arteries) branch vessels in a cryogel abdominal aortic phantom. This was repeated with conventional x-ray fluoroscopy by using clinical catheters and guidewires. Mean procedure times and percentage success data were analyzed with linear mixed-effects regression. Results The MARC catheter tip was visible at 1.5 T and 3 T. Among inexperienced operators, MARC MR imaging guidance was not statistically different from x-ray guidance at 1.5 T (67% successful vessel selection turns with MR imaging vs 76% with x-ray guidance, P = .157) and at 3 T (75% successful turns with MR imaging vs 76% with x-ray guidance, P = .869). Experienced operators were more successful in catheterizing vessels with x-ray guidance (98% success within 60 seconds) than with 1.5-T (65%, P < .001) or 3-T (75%) MR imaging. Among inexperienced operators, mean procedure time was nearly equivalent by using MR imaging (31 seconds) and x-ray guidance (34 seconds, P = .436). Among experienced operators, catheterization was faster with x-ray guidance (20 seconds) compared with 1.5-T MR imaging (42 seconds, P < .001), but MARC guidance improved at 3 T (31 seconds). MARC MR imaging guidance at 3 T was not significantly different from x-ray guidance for the celiac (P = .755), superior mesenteric (P = .358), and inferior mesenteric (P = .065) arteries. Conclusion Multiplanar navigation with a new MARC catheter with real-time MR imaging at 1.5 T and 3 T is feasible and comparable to x-ray guidance for anteroposterior vessels at 3 T in a vascular phantom. © RSNA, 2015 Online supplemental material is available for this article. PMID:26030659

A medical application integrating remote 3D visualization tools to access picture archiving and communication system on mobile devices.

PubMed

He, Longjun; Ming, Xing; Liu, Qian

2014-04-01

With computing capability and display size growing, the mobile device has been used as a tool to help clinicians view patient information and medical images anywhere and anytime. However, for direct interactive 3D visualization, which plays an important role in radiological diagnosis, the mobile device cannot provide a satisfactory quality of experience for radiologists. This paper developed a medical system that can get medical images from the picture archiving and communication system on the mobile device over the wireless network. In the proposed application, the mobile device got patient information and medical images through a proxy server connecting to the PACS server. Meanwhile, the proxy server integrated a range of 3D visualization techniques, including maximum intensity projection, multi-planar reconstruction and direct volume rendering, to providing shape, brightness, depth and location information generated from the original sectional images for radiologists. Furthermore, an algorithm that changes remote render parameters automatically to adapt to the network status was employed to improve the quality of experience. Finally, performance issues regarding the remote 3D visualization of the medical images over the wireless network of the proposed application were also discussed. The results demonstrated that this proposed medical application could provide a smooth interactive experience in the WLAN and 3G networks.

Volumetric three-dimensional display system with rasterization hardware

NASA Astrophysics Data System (ADS)

Favalora, Gregg E.; Dorval, Rick K.; Hall, Deirdre M.; Giovinco, Michael; Napoli, Joshua

2001-06-01

An 8-color multiplanar volumetric display is being developed by Actuality Systems, Inc. It will be capable of utilizing an image volume greater than 90 million voxels, which we believe is the greatest utilizable voxel set of any volumetric display constructed to date. The display is designed to be used for molecular visualization, mechanical CAD, e-commerce, entertainment, and medical imaging. As such, it contains a new graphics processing architecture, novel high-performance line- drawing algorithms, and an API similar to a current standard. Three-dimensional imagery is created by projecting a series of 2-D bitmaps ('image slices') onto a diffuse screen that rotates at 600 rpm. Persistence of vision fuses the slices into a volume-filling 3-D image. A modified three-panel Texas Instruments projector provides slices at approximately 4 kHz, resulting in 8-color 3-D imagery comprised of roughly 200 radially-disposed slices which are updated at 20 Hz. Each slice has a resolution of 768 by 768 pixels, subtending 10 inches. An unusual off-axis projection scheme incorporating tilted rotating optics is used to maintain good focus across the projection screen. The display electronics includes a custom rasterization architecture which converts the user's 3- D geometry data into image slices, as well as 6 Gbits of DDR SDRAM graphics memory.

Three-dimensional reconstruction and display of the heart, lungs and circulation by multiplanar X-ray scanning videodensitometry

NASA Technical Reports Server (NTRS)

Robb, R. A.; Ritman, E. L.; Wood, E. H.

1975-01-01

A device was developed which makes possible the dynamic reconstruction of the heart and lungs within the intact thorax of a living dog or human and which can record approximately 30 multiplanar X-ray images of the thorax practically instantaneously, and at frequent enough intervals of time and with sufficient density and spatial resolution to capture and resolve the most rapid changes in cardiac structural detail throughout each cardiac cycle. It can be installed in a clinical diagnostic setting as well as in a research environment and its construction and application for determination and display in real-time modes of cross sections of the functioning thorax and its contents of living animals and man is technologically feasible.

Application of Curved MPR Algorithm to High Resolution 3 Dimensional T2 Weighted CISS Images for Virtual Uncoiling of Membranous Cochlea as an Aid for Cochlear Morphometry.

PubMed

Kumar, Joish Upendra; Kavitha, Y

2017-02-01

With the use of various surgical techniques, types of implants, the preoperative assessment of cochlear dimensions is becoming increasingly relevant prior to cochlear implantation. High resolution CISS protocol MRI gives a better assessment of membranous cochlea, cochlear nerve, and membranous labyrinth. Curved Multiplanar Reconstruction (MPR) algorithm provides better images that can be used for measuring dimensions of membranous cochlea. To ascertain the value of curved multiplanar reconstruction algorithm in high resolution 3-Dimensional T2 Weighted Gradient Echo Constructive Interference Steady State (3D T2W GRE CISS) imaging for accurate morphometry of membranous cochlea. Fourteen children underwent MRI for inner ear assessment. High resolution 3D T2W GRE CISS sequence was used to obtain images of cochlea. Curved MPR reconstruction algorithm was used to virtually uncoil the membranous cochlea on the volume images and cochlear measurements were done. Virtually uncoiled images of membranous cochlea of appropriate resolution were obtained from the volume data obtained from the high resolution 3D T2W GRE CISS images, after using curved MPR reconstruction algorithm mean membranous cochlear length in the children was 27.52 mm. Maximum apical turn diameter of membranous cochlea was 1.13 mm, mid turn diameter was 1.38 mm, basal turn diameter was 1.81 mm. Curved MPR reconstruction algorithm applied to CISS protocol images facilitates in getting appropriate quality images of membranous cochlea for accurate measurements.

Osteoblastic lesion screening with an advanced post-processing package enabling in-plane rib reading in CT-images.

PubMed

Seuss, Hannes; Dankerl, Peter; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

2016-05-20

To evaluate screening and diagnostic accuracy for the detection of osteoblastic rib lesions using an advanced post-processing package enabling in-plane rib reading in CT-images. We retrospectively assessed the CT-data of 60 consecutive prostate cancer patients by applying dedicated software enabling in-plane rib reading. Reading the conventional multiplanar reconstructions was considered to be the reference standard. To simulate clinical practice, the reader was given 10 s to screen for sclerotic rib lesions in each patient applying both approaches. Afterwards, every rib was evaluated individually with both approaches without a time limit. Sensitivities, specificities, positive/negative predictive values and the time needed for detection were calculated depending on the lesion's size (largest diameter < 5 mm, 5-10 mm, > 10 mm). In 53 of 60 patients, all ribs were properly displayed in plane, in five patients ribs were partially displayed correctly, and in two patients none of the ribs were displayed correctly. During the 10-s screening approach all patients with sclerotic rib lesions were correctly identified reading the in-plane images (including the patients without a correct rib segmentation), whereas 14 of 23 patients were correctly identified reading conventional multiplanar images. Overall screening sensitivity, specificity, and positive/negative predictive values were 100/27.0/46.0/100 %, respectively, for in-plane reading and 60.9/100/100/80.4 %, respectively, for multiplanar reading. Overall diagnostic (no time limit) sensitivity, specificity, and positive/negative predictive values of in-plane reading were 97.8/92.8/74.6/99.5 %, respectively. False positive results predominantly occurred for lesions <5 mm in size. In-plane reading of the ribs allows reliable detection of osteoblastic lesions for screening purposes. The limited specificity results from false positives predominantly occurring for small lesions.

Detection of flat colorectal polyps at screening CT colonography in comparison with conventional polypoid lesions.

PubMed

Sakamoto, Takashi; Mitsuzaki, Katsuhiko; Utsunomiya, Daisuke; Matsuda, Katsuhiko; Yamamura, Sadahiro; Urata, Joji; Kawakami, Megumi; Yamashita, Yasuyuki

2012-09-01

Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Detection sensitivity for flat polyps was 31.3%, 44.4%, and 87.5% for lesions measuring 2-3 mm, 4-5 mm, and ≥6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6%, 79.0%, and 91.7%. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.

Splitting a colon geometry with multiplanar clipping

NASA Astrophysics Data System (ADS)

Ahn, David K.; Vining, David J.; Ge, Yaorong; Stelts, David R.

1998-06-01

Virtual colonoscopy, a recent three-dimensional (3D) visualization technique, has provided radiologists with a unique diagnostic tool. Using this technique, a radiologist can examine the internal morphology of a patient's colon by navigating through a surface-rendered model that is constructed from helical computed tomography image data. Virtual colonoscopy can be used to detect early forms of colon cancer in a way that is less invasive and expensive compared to conventional endoscopy. However, the common approach of 'flying' through the colon lumen to visually search for polyps is tedious and time-consuming, especially when a radiologist loses his or her orientation within the colon. Furthermore, a radiologist's field of view is often limited by the 3D camera position located inside the colon lumen. We have developed a new technique, called multi-planar geometry clipping, that addresses these problems. Our algorithm divides a complex colon anatomy into several smaller segments, and then splits each of these segments in half for display on a static medium. Multi-planar geometry clipping eliminates virtual colonoscopy's dependence upon expensive, real-time graphics workstations by enabling radiologists to globally inspect the entire internal surface of the colon from a single viewpoint.

Image quality of multiplanar reconstruction of pulmonary CT scans using adaptive statistical iterative reconstruction.

PubMed

Honda, O; Yanagawa, M; Inoue, A; Kikuyama, A; Yoshida, S; Sumikawa, H; Tobino, K; Koyama, M; Tomiyama, N

2011-04-01

We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR). Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality. The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (p<0.01). Contrast medium in the injection syringe was scanned to analyse image quality; ASIR did not suppress the severe artefacts of contrast medium. In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode.

Endometrial cancer: magnetic resonance imaging.

PubMed

Manfredi, R; Gui, B; Maresca, G; Fanfani, F; Bonomo, L

2005-01-01

Carcinoma of the endometrium is the most common invasive gynecologic malignancy of the female genital tract. Clinically, patients with endometrial carcinoma present with abnormal uterine bleeding. The role of magnetic resonance imaging (MRI) in endometrial carcinoma is disease staging and treatment planning. MRI has been shown to be the most valuable imaging mod-ality in this task, compared with endovaginal ultrasound and computed tomography, because of its intrinsic contrast resolution and multiplanar capability. MRI protocol includes axial T1-weighted images; axial, sagittal, and coronal T2-weighted images; and dynamic gadolinium-enhanced T1-weighted imaging. MR examination is usually performed in the supine position with a phased array multicoil using a four-coil configuration. Endometrial carcinoma is isointense with the normal endometrium and myometrium on noncontrast T1-weighted images and has a variable appearance on T2-weighted images demonstrating heterogeneous signal intensity. The appearance of noninvasive endometrial carcinoma on MRI is characterized by a normal or thickened endometrium, with an intact junctional zone and a sharp tumor-myometrium interface. Invasive endometrial carcinoma is characterized disruption or irregularity of the junctional zone by intermediate signal intensity mass on T2-weighted images. Invasion of the cervical stroma is diagnosed when the low signal intensity cervical stroma is disrupted by the higher signal intensity endometrial carcinoma. MRI in endometrial carcinoma performs better than other imaging modalities in disease staging and treatment planning. Further, the accuracy and the cost of MRI are equivalent to those of surgical staging.

Case report highlighting how wound path identification on CT can help identify organ damage in abdominal blast injuries.

PubMed

Fischer, Tatjana V; Folio, Les R; Backus, Christopher E; Bunger, Rolf

2012-01-01

Penetrating trauma is frequently encountered in forward deployed military combat hospitals. Abdominal blast injuries represent nearly 11% of combat injuries, and multiplanar computed tomography imaging is optimal for injury assessment and surgical planning. We describe a multiplanar approach to assessment of blast and ballistic injuries, which allows for more expeditious detection of missile tracts and damage caused along the path. Precise delineation of the trajectory path and localization of retained fragments enables time-saving and detailed evaluation of associated tissue and vascular injury. For consistent and reproducible documentation of fragment locations in the body, we propose a localization scheme based on Cartesian coordinates to report 3-dimensional locations of fragments and demonstrating the application in three cases of abdominal blast injury.

Image quality analysis to reduce dental artifacts in head and neck imaging with dual-source computed tomography.

PubMed

Ketelsen, D; Werner, M K; Thomas, C; Tsiflikas, I; Koitschev, A; Reimann, A; Claussen, C D; Heuschmid, M

2009-01-01

Important oropharyngeal structures can be superimposed by metallic artifacts due to dental implants. The aim of this study was to compare the image quality of multiplanar reconstructions and an angulated spiral in dual-source computed tomography (DSCT) of the neck. Sixty-two patients were included for neck imaging with DSCT. MPRs from an axial dataset and an additional short spiral parallel to the mouth floor were acquired. Leading anatomical structures were then evaluated with respect to the extent to which they were affected by dental artifacts using a visual scale, ranging from 1 (least artifacts) to 4 (most artifacts). In MPR, 87.1 % of anatomical structures had significant artifacts (3.12 +/- 0.86), while in angulated slices leading anatomical structures of the oropharynx showed negligible artifacts (1.28 +/- 0.46). The diagnostic growth due to primarily angulated slices concerning artifact severity was significant (p < 0.01). MPRs are not capable of reducing dental artifacts sufficiently. In patients with dental artifacts overlying the anatomical structures of the oropharynx, an additional short angulated spiral parallel to the floor of the mouth is recommended and should be applied for daily routine. As a result of the static gantry design of DSCT, the use of a flexible head holder is essential.

Automatic segmentation of the liver using multi-planar anatomy and deformable surface model in abdominal contrast-enhanced CT images

NASA Astrophysics Data System (ADS)

Jang, Yujin; Hong, Helen; Chung, Jin Wook; Yoon, Young Ho

2012-02-01

We propose an effective technique for the extraction of liver boundary based on multi-planar anatomy and deformable surface model in abdominal contrast-enhanced CT images. Our method is composed of four main steps. First, for extracting an optimal volume circumscribing a liver, lower and side boundaries are defined by positional information of pelvis and rib. An upper boundary is defined by separating the lungs and heart from CT images. Second, for extracting an initial liver volume, optimal liver volume is smoothed by anisotropic diffusion filtering and is segmented using adaptively selected threshold value. Third, for removing neighbor organs from initial liver volume, morphological opening and connected component labeling are applied to multiple planes. Finally, for refining the liver boundaries, deformable surface model is applied to a posterior liver surface and missing left robe in previous step. Then, probability summation map is generated by calculating regional information of the segmented liver in coronal plane, which is used for restoring the inaccurate liver boundaries. Experimental results show that our segmentation method can accurately extract liver boundaries without leakage to neighbor organs in spite of various liver shape and ambiguous boundary.

Cone beam tomographic imaging anatomy of the maxillofacial region.

PubMed

Angelopoulos, Christos

2008-10-01

Multiplanar imaging is a fairly new concept in diagnostic imaging available with a number of contemporary imaging modalities such as CT, MR imaging, diagnostic ultrasound, and others. This modality allows reconstruction of images in different planes (flat or curved) from a volume of data that was acquired previously. This concept makes the diagnostic process more interactive, and proper use may increase diagnostic potential. At the same time, the complexity of the anatomical structures on the maxillofacial region may make it harder for these images to be interpreted. This article reviews the anatomy of maxillofacial structures in planar imaging, and more specifically cone-beam CT images.

Navigation concepts for magnetic resonance imaging-guided musculoskeletal interventions.

PubMed

Busse, Harald; Kahn, Thomas; Moche, Michael

2011-08-01

Image-guided musculoskeletal (MSK) interventions are a widely used alternative to open surgical procedures for various pathological findings in different body regions. They traditionally involve one of the established x-ray imaging techniques (radiography, fluoroscopy, computed tomography) or ultrasound scanning. Over the last decades, magnetic resonance imaging (MRI) has evolved into one of the most powerful diagnostic tools for nearly the whole body and has therefore been increasingly considered for interventional guidance as well.The strength of MRI for MSK applications is a combination of well-known general advantages, such as multiplanar and functional imaging capabilities, wide choice of tissue contrasts, and absence of ionizing radiation, as well as a number of MSK-specific factors, for example, the excellent depiction of soft-tissue tumors, nonosteolytic bone changes, and bone marrow lesions. On the downside, the magnetic resonance-compatible equipment needed, restricted space in the magnet, longer imaging times, and the more complex workflow have so far limited the number of MSK procedures under MRI guidance.Navigation solutions are generally a natural extension of any interventional imaging system, in particular, because powerful hardware and software for image processing have become routinely available. They help to identify proper access paths, provide accurate feedback on the instrument positions, facilitate the workflow in an MRI environment, and ultimately contribute to procedural safety and success.The purposes of this work were to describe some basic concepts and devices for MRI guidance of MSK procedures and to discuss technical and clinical achievements and challenges for some selected implementations.

Image quality of multiplanar reconstruction of pulmonary CT scans using adaptive statistical iterative reconstruction

PubMed Central

Honda, O; Yanagawa, M; Inoue, A; Kikuyama, A; Yoshida, S; Sumikawa, H; Tobino, K; Koyama, M; Tomiyama, N

2011-01-01

Objective We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR). Methods Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality. Results The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (p<0.01). Contrast medium in the injection syringe was scanned to analyse image quality; ASIR did not suppress the severe artefacts of contrast medium. Conclusion In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode. PMID:21081572

Helical CT scan with 2D and 3D reconstructions and virtual endoscopy versus conventional endoscopy in the assessment of airway disease in neonates, infants and children.

PubMed

Yunus, Mahira

2012-11-01

To study the use of helical computed tomography 2-D and 3-D images, and virtual endoscopy in the evaluation of airway disease in neonates, infants and children and its value in lesion detection, characterisation and extension. Conducted at Al-Noor Hospital, Makkah, Saudi Arabia, from January 1 to June 30, 2006, the study comprised of 40 patients with strider, having various causes of airway obstruction. They were examined by helical CT scan with 2-D and 3-D reconstructions and virtual endoscopy. The level and characterisation of lesions were carried out and results were compared with actual endoscopic findings. Conventional endoscopy was chosen as the gold standard, and the evaluation of endoscopy was done in terms of sensitivity and specificity of the procedure. For statistical purposes, SPSS version 10 was used. All CT methods detected airway stenosis or obstruction. Accuracy was 98% (n=40) for virtual endoscopy, 96% (n=48) for 3-D external rendering, 90% (n=45) for multiplanar reconstructions and 86% (n=43) for axial images. Comparing the results of 3-D internal and external volume rendering images with conventional endoscopy for detection and grading of stenosis were closer than with 2-D minimum intensity multiplanar reconstruction and axial CT slices. Even high-grade stenosis could be evaluated with virtual endoscope through which conventional endoscope cannot be passed. A case of 4-year-old patient with tracheomalacia could not be diagnosed by helical CT scan and virtual bronchoscopy which was diagriosed on conventional endoscopy and needed CT scan in inspiration and expiration. Virtual endoscopy [VE] enabled better assessment of stenosis compared to the reading of 3-D external rendering, 2-D multiplanar reconstruction [MPR] or axial slices. It can replace conventional endoscopy in the assessment of airway disease without any additional risk.

Atypical extraspinal musculoskeletal tuberculosis in immunocompetent patients: part II, tuberculous myositis, tuberculous bursitis, and tuberculous tenosynovites.

PubMed

Abdelwahab, Ibrahim Fikry; Bianchi, Stefano; Martinoli, Carlo; Klein, Michael; Hermann, George

2006-12-01

Tuberculosis involving the soft tissue from adjacent bone or joint is well recognized. However, primary tuberculous pyomyositis, tuberculous bursitis, and tuberculous tenosynovitis are rare entities constituting 1% of skeletal tuberculosis. Tuberculous tenosynovitis involves most commonly the tendon sheaths of the hand and wrist, and tuberculous bursitis occurs most commonly around the hip. The greater trochanteric bursa and the greater trochanter are the most frequent sites of tuberculous bursitis. Cases of primary tuberculous pyomyositis and tenosynovitis of the tendons of the ankle and foot are seldom reported in the radiology literature. All imaging modalities-plain radiography, bone scan, computed tomography, and magnetic resonance imaging (MRI)--provide information that is helpful in determining therapy. MRI in particular, with its multiplanar capabilities and superb contrast of soft tissue, can demonstrate the extent of the soft tissue mass and access the adjacent bones and joints. However, MRI has no diagnostic specificity in regard to tuberculosis, and in nonendemic areas, biopsy is strongly recommended. All patients in this review were permanent residents of North America or Western Europe and were immunocompetent. Examples of atypical presentations of the above entities are demonstrated.

New horizons for study of the cardiopulmonary and circulatory systems. [image reconstruction techniques

NASA Technical Reports Server (NTRS)

Wood, E. H.

1976-01-01

The paper discusses the development of computer-controlled three-dimensional reconstruction techniques designed to determine the dynamic changes in the true shape and dimensions of the epi- and endocardial surfaces of the heart, along with variable time base (stop-action to real-time) displays of the transmural distribution of the coronary microcirculation and the three-dimensional anatomy of the macrovasculature in all regions of the body throughout individual cardiac and/or respiratory cycles. A technique for reconstructing a cross section of the heart from multiplanar videoroentgenograms is outlined. The capability of high spatial and high temporal resolution scanning videodensitometry makes possible measurement of the appearance, mean transit and clearance of roentgen opaque substances in three-dimensional space through the myocardium with a degree of simultaneous anatomic and temporal resolution not obtainable by current isotope techniques. The distribution of a variety of selected chemical elements or biologic materials within a body portion can also be determined.

Non-invasive coronary angiography with multislice computed tomography. Technology, methods, preliminary experience and prospects.

PubMed

Traversi, Egidio; Bertoli, Giuseppe; Barazzoni, Giancarlo; Baldi, Maurizia; Tramarin, Roberto

2004-02-01

The recent technical developments in multislice computed tomography (MSCT), with ECG retro-gated image reconstruction, have elicited great interest in the possibility of accurate non-invasive imaging of the coronary arteries. The latest generation of MSCT systems with 8-16 rows of detectors permits acquisition of the whole cardiac volume during a single 15-20 s breath-hold with a submillimetric definition of the images and an outstanding signal-to-noise ratio. Thus the race which, between MSCT, electron beam computed tomography and cardiac magnetic resonance imaging, can best provide routine and reliable imaging of the coronary arteries in clinical practice has recommenced. Currently available MSCT systems offer different options for both cardiac image acquisition and reconstruction, including multiplanar and curved multiplanar reconstruction, three-dimensional volume rendering, maximum intensity projection, and virtual angioscopy. In our preliminary experience including 176 patients suffering from known or suspected coronary artery disease, MSCT was feasible in 161 (91.5%) and showed a sensitivity of 80.4% and a specificity of 80.3%, with respect to standard coronary angiography, in detecting critical stenosis in coronary arteries and artery or venous bypass grafts. These results correspond to a positive predictive value of 58.6% and a negative predictive value of 92.2%. The true role that MSCT is likely to play in the future in non-invasive coronary imaging is still to be defined. Nevertheless, the huge amount of data obtainable by MSCT along with the rapid technological advances, shorter acquisition times and reconstruction algorithm developments will make the technique stronger, and possible applications are expected not only for non-invasive coronary angiography, but also for cardiac function and myocardial perfusion evaluation, as an all-in-one examination.

[Possibilities of magnetic resonance tomography in diagnostic imaging of the shoulder joint].

PubMed

Reiser, M; Erlemann, R; Bongartz, G; Pauly, T; Kunze, V; Mathiass, H H; Peters, P E

1988-02-01

By virtue of its multiplanar representation, magnetic resonance imaging (MRI) allows clear visualization of the complex anatomical relationships of the shoulder joint. In addition to axial planes, slices perpendicular and parallel to the glenoid cavity are used to good advantage. In tears of the rotator cuff an increase in signal intensity within the cuff is recognized in T2- and proton-density-weighted images. Lesions of the glenoid labrum following luxations of the glenohumeral joint can be detected and classified using MRI. The diagnostic value of MRI as compared with other imaging modalities will have to be evaluated in larger series with operative verification.

Radiology of pancreatic neoplasms: An update

PubMed Central

de la Santa, Luis Gijón; Retortillo, José Antonio Pérez; Miguel, Ainhoa Camarero; Klein, Lea Marie

2014-01-01

Diagnostic imaging is an important tool to evaluate pancreatic neoplasms. We describe the imaging features of pancreatic malignancies and their benign mimics. Accurate detection and staging are essential for ensuring appropriate selection of patients who will benefit from surgery and for preventing unnecessary surgeries in patients with unresectable disease. Ultrasound, multidetector computed tomography with multiplanar reconstruction and magnetic resonance imaging can help to do a correct diagnosis. Radiologists should be aware of the wide variety of anatomic variants and pathologic conditions that may mimic pancreatic neoplasms. The knowledge of the most important characteristic key findings may facilitate the right diagnosis. PMID:25232458

Radiology of pancreatic neoplasms: An update.

PubMed

de la Santa, Luis Gijón; Retortillo, José Antonio Pérez; Miguel, Ainhoa Camarero; Klein, Lea Marie

2014-09-15

Diagnostic imaging is an important tool to evaluate pancreatic neoplasms. We describe the imaging features of pancreatic malignancies and their benign mimics. Accurate detection and staging are essential for ensuring appropriate selection of patients who will benefit from surgery and for preventing unnecessary surgeries in patients with unresectable disease. Ultrasound, multidetector computed tomography with multiplanar reconstruction and magnetic resonance imaging can help to do a correct diagnosis. Radiologists should be aware of the wide variety of anatomic variants and pathologic conditions that may mimic pancreatic neoplasms. The knowledge of the most important characteristic key findings may facilitate the right diagnosis.

[Application of computed tomography (CT) examination for forensic medicine].

PubMed

Urbanik, Andrzej; Chrzan, Robert

2013-01-01

The aim of the study is to present a own experiences in usage of post mortem CT examination for forensic medicine. With the help of 16-slice CT scanner 181 corpses were examined. Obtained during acquisition imaging data are later developed with dedicated programmes. Analyzed images were extracted from axial sections, multiplanar reconstructions as well as 3D reconstructions. Gained information helped greatly when classical autopsy was performed by making it more accurate. A CT scan images recorded digitally enable to evaluate corpses at any time, despite processes of putrefaction or cremation. If possible CT examination should precede classical autopsy.

Reproducibility of Abdominal Aortic Aneurysm Diameter Measurement and Growth Evaluation on Axial and Multiplanar Computed Tomography Reformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dugas, Alexandre; Therasse, Eric; Kauffmann, Claude

2012-08-15

Purpose: To compare different methods measuring abdominal aortic aneurysm (AAA) maximal diameter (Dmax) and its progression on multidetector computed tomography (MDCT) scan. Materials and Methods: Forty AAA patients with two MDCT scans acquired at different times (baseline and follow-up) were included. Three observers measured AAA diameters by seven different methods: on axial images (anteroposterior, transverse, maximal, and short-axis views) and on multiplanar reformation (MPR) images (coronal, sagittal, and orthogonal views). Diameter measurement and progression were compared over time for the seven methods. Reproducibility of measurement methods was assessed by intraclass correlation coefficient (ICC) and Bland-Altman analysis. Results: Dmax, as measuredmore » on axial slices at baseline and follow-up (FU) MDCTs, was greater than that measured using the orthogonal method (p = 0.046 for baseline and 0.028 for FU), whereas Dmax measured with the orthogonal method was greater those using all other measurement methods (p-value range: <0.0001-0.03) but anteroposterior diameter (p = 0.18 baseline and 0.10 FU). The greatest interobserver ICCs were obtained for the orthogonal and transverse methods (0.972) at baseline and for the orthogonal and sagittal MPR images at FU (0.973 and 0.977). Interobserver ICC of the orthogonal method to document AAA progression was greater (ICC = 0.833) than measurements taken on axial images (ICC = 0.662-0.780) and single-plane MPR images (0.772-0.817). Conclusion: AAA Dmax measured on MDCT axial slices overestimates aneurysm size. Diameter as measured by the orthogonal method is more reproducible, especially to document AAA progression.« less

Hard- and soft-tissue profiles of the midface region in patients with skeletal Class III malocclusion using cone-beam computed tomography multiplanar-reconstructed image analysis.

PubMed

Kim, Bomi; Lee, Hyung-Chul; Kim, Seong-Hun; Kim, Yongil; Son, Woosung; Kim, Seong Sik

2018-05-01

This study examined cone-beam computed tomography (CBCT)-derived multiplanar-reconstructed (MPR) cross-sections to clarify the salient characteristics of patients with skeletal class III malocclusion with midface deficiency (MD). The horizontal and sagittal plane intersection points were identified for middle-third facial analysis in 40 patients in the MD or normal (N) groups. MPR images acquired parallel to each horizontal plane were used for length and angular measurements. A comparison of the MD and N groups revealed significant differences in the zygoma prominence among female patients. The convex zygomatic area in the N group was larger than that in the MD group, and the inferior part of the midface in the N group was smaller than that in the MD group for both male and female patients. A significant difference was observed in the concave middle maxillary area among male patients. This study was conducted to demonstrate the difference between MD and normal face through MPR images derived from CBCT. Male patients in the MD group had a more flattened face than did those in the N group. Female patients in the MD group showed a concave-shaped lower section of the zygoma, which tended to have more severe MD. These findings indicate that orthognathic surgery to improve skeletal discrepancy requires different approaches in male and female patients.

Magnetic resonance imaging of the fetal brain.

PubMed

Tee, L Mf; Kan, E Yl; Cheung, J Cy; Leung, W C

2016-06-01

This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

A novel multi-planar radiography method for three dimensional pose reconstruction of the patellofemoral and tibiofemoral joints after arthroplasty.

PubMed

Amiri, Shahram; Wilson, David R; Masri, Bassam A; Sharma, Gulshan; Anglin, Carolyn

2011-06-03

Determining the 3D pose of the patella after total knee arthroplasty is challenging. The commonly used single-plane fluoroscopy is prone to large errors in the clinically relevant mediolateral direction. A conventional fixed bi-planar setup is limited in the minimum angular distance between the imaging planes necessary for visualizing the patellar component, and requires a highly flexible setup to adjust for the subject-specific geometries. As an alternative solution, this study investigated the use of a novel multi-planar imaging setup that consists of a C-arm tracked by an external optoelectric tracking system, to acquire calibrated radiographs from multiple orientations. To determine the accuracies, a knee prosthesis was implanted on artificial bones and imaged in simulated 'Supine' and 'Weightbearing' configurations. The results were compared with measures from a coordinate measuring machine as the ground-truth reference. The weightbearing configuration was the preferred imaging direction with RMS errors of 0.48 mm and 1.32 ° for mediolateral shift and tilt of the patella, respectively, the two most clinically relevant measures. The 'imaging accuracies' of the system, defined as the accuracies in 3D reconstruction of a cylindrical ball bearing phantom (so as to avoid the influence of the shape and orientation of the imaging object), showed an order of magnitude (11.5 times) reduction in the out-of-plane RMS errors in comparison to single-plane fluoroscopy. With this new method, complete 3D pose of the patellofemoral and tibiofemoral joints during quasi-static activities can be determined with a many-fold (up to 8 times) (3.4mm) improvement in the out-of-plane accuracies compared to a conventional single-plane fluoroscopy setup. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Fetal neurosonography using 3-dimensional multiplanar sonography].

PubMed

Chaoui, R; Heling, K S; Kainer, F; Karl, K

2012-04-01

This review focuses on the examination of the fetal brain, using three-dimensional (3D) ultrasound and the multiplanar rendering mode (MPR). The routine examination of the brain is achieved with axial planes but a dedicated fetal neurosonogram requires additional coronal and sagittal views, in order to provide a complete view of the different brain structures. Because these planes are difficult to obtain under many conditions, the present paper shows how 3D MPR allows one to obtain 1 or multiple reconstructed images from a digital volume. The display can be either as orthogonal planes, tomographic planes with parallel slices or as one single plane of the region of interest, which can be selected by the examiner. This approach allows easily the demonstration of the corpus callosum, the cerebellar vermis, the three-horn view, the foetal hippocampus and other regions. In addition, early neurosonography of the developing brain from the 7th week of pregnancy onwards can be achieved. © Georg Thieme Verlag KG Stuttgart · New York.

[3D FSPGR (fast spoiled gradient echo) magnetic resonance imaging in the diagnosis of focal cortical dysplasia in children].

PubMed

Alikhanov, A A; Sinitsyn, V E; Perepelova, E M; Mukhin, K Iu; Demushkina, A A; Omarova, M O; Piliia, S V

2001-01-01

Small dysplastic lesions of the cerebral cortex are often missed by conventional MRI methods. The identification of subtle structural abnormalities by traditional multiplanar rectilinear slices is often limited by the complex convolutional pattern of the brain. We used a method of FSPGR (fast spoiled gradient-echo) of three-dimensional MRI data that improves the anatomical display of the sulcal structure of the hemispheric convexities. It also reduces the asymmetric sampling of gray-white matter that may lead to false-positive results. We present 5 from 12 patients with dysplastic cortical lesions in whom conventional two-dimensional and three-dimensional MRI with multiplanar reformatting was initially considered normal. Subsequent studies using 3D FSPGR identified various types of focal cortical dysplasia in all. These results indicate that an increase in the detection of subtle focal dysplastic lesions may be accomplished when one improves the anatomical display of the brain sulcal structure by performing 3D FSPGR.

MyFreePACS: a free web-based radiology image storage and viewing tool.

PubMed

de Regt, David; Weinberger, Ed

2004-08-01

We developed an easy-to-use method for central storage and subsequent viewing of radiology images for use on any PC equipped with Internet Explorer. We developed MyFreePACS, a program that uses a DICOM server to receive and store images and transmit them over the Web to the MyFreePACS Web client. The MyFreePACS Web client is a Web page that uses an ActiveX control for viewing and manipulating images. The client contains many of the tools found in modern image viewing stations including 3D localization and multiplanar reformation. The system is built entirely with free components and is freely available for download and installation from the Web at www.myfreepacs.com.

A Current Review of the Meniscus Imaging: Proposition of a Useful Tool for Its Radiologic Analysis

PubMed Central

Lefevre, Nicolas; Naouri, Jean Francois; Herman, Serge; Gerometta, Antoine; Klouche, Shahnaz; Bohu, Yoann

2016-01-01

The main objective of this review was to present a synthesis of the current literature in order to provide a useful tool to clinician in radiologic analysis of the meniscus. All anatomical descriptions were clearly illustrated by MRI, arthroscopy, and/or drawings. The value of standard radiography is extremely limited for the assessment of meniscal injuries but may be indicated to obtain a differential diagnosis such as osteoarthritis. Ultrasound is rarely used as a diagnostic tool for meniscal pathologies and its accuracy is operator-dependent. CT arthrography with multiplanar reconstructions can detect meniscus tears that are not visible on MRI. This technique is also useful in case of MRI contraindications, in postoperative assessment of meniscal sutures and the condition of cartilage covering the articular surfaces. MRI is the most accurate and less invasive method for diagnosing meniscal lesions. MRI allows confirming and characterizing the meniscal lesion, the type, the extension, its association with a cyst, the meniscal extrusion, and assessing cartilage and subchondral bone. New 3D-MRI in three dimensions with isotropic resolution allows the creation of multiplanar reformatted images to obtain from an acquisition in one sectional plane reconstructions in other spatial planes. 3D MRI should further improve the diagnosis of meniscal tears. PMID:27057352

High resolution MRI imaging at 9.4 Tesla of the osteochondral unit in a translational model of articular cartilage repair.

PubMed

Goebel, Lars; Müller, Andreas; Bücker, Arno; Madry, Henning

2015-04-16

Non-destructive structural evaluation of the osteochondral unit is challenging. Here, the capability of high-field magnetic resonance imaging (μMRI) at 9.4 Tesla (T) was explored to examine osteochondral repair ex vivo in a preclinical large animal model. A specific aim of this study was to detect recently described alterations of the subchondral bone associated with cartilage repair. Osteochondral samples of medial femoral condyles from adult ewes containing full-thickness articular cartilage defects treated with marrow stimulation were obtained after 6 month in vivo and scanned in a 9.4 T μMRI. Ex vivo imaging of small osteochondral samples (typical volume: 1-2 cm(3)) at μMRI was optimised by variation of repetition time (TR), time echo (TE), flip angle (FA), spatial resolution and number of excitations (NEX) from standard MultiSliceMultiEcho (MSME) and three-dimensional (3D) spoiled GradientEcho (SGE) sequences. A 3D SGE sequence with the parameters: TR = 10 ms, TE = 3 ms, FA = 10°, voxel size = 120 × 120 × 120 μm(3) and NEX = 10 resulted in the best fitting for sample size, image quality, scanning time and artifacts. An isovolumetric voxel shape allowed for multiplanar reconstructions. Within the osteochondral unit articular cartilage, cartilaginous repair tissue and bone marrow could clearly be distinguished from the subchondral bone plate and subarticular spongiosa. Specific alterations of the osteochondral unit associated with cartilage repair such as persistent drill holes, subchondral bone cysts, sclerosis of the subchondral bone plate and of the subarticular spongiosa and intralesional osteophytes were precisely detected. High resolution, non-destructive ex vivo analysis of the entire osteochondral unit in a preclinical large animal model that is sufficient for further analyses is possible using μMRI at 9.4 T. In particular, 9.4 T is capable of accurately depicting alterations of the subchondral bone that are associated with osteochondral repair.

In vivo anatomical analysis of arterial contact with trigeminal nerve: detection with three-dimensional spoiled grass imaging.

PubMed

Ueda, F; Suzuki, M; Fujinaga, Y; Kadoya, M; Takashima, T

1999-09-01

The purpose of this study was to review the normal in vivo neurovascular relationship between the trigeminal nerve and surrounding arteries without the use of volunteers. 290 nerves in 145 cases were reviewed during a 1-year period. Axial source images and multiplanar reconstructed (MPR) images were used to determine the neurovascular contact and direction of contact. Multiplanar volume reformation (MPVR) was used to identify the contact vessels and to demonstrate the relationship between the nerve and arteries. Vascular contact was found in 29% of the 290 nerves (83 nerves). The arteries involved were the superior cerebellar artery (SCA) or the anterior inferior cerebellar artery (AICA). Vascular contact with two arteries was found in 3%. Of the 286 asymptomatic nerves, the nerve was located between the two vessels in 3% and compression was seen in 1%. Three points of vascular contact by the two arteries were identified in one asymptomatic nerve. The direction of contact between the SCA and the nerve was superior (38%), superomedial (32%) or medial (15%) in most cases. The direction of contact between the AICA and the nerve was inferior, inferolateral or lateral in all cases. Vascular contact at the root entry zone (REZ) was noted in 90%. Four nerves were affected by trigeminal neuralgia, one of which touched an artery and two were compressed. It was concluded that arterial contact can be assessed without difficulty but evaluation of vascular compression is not easy.

Quantification of resolution in multiplanar reconstructions for digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Vent, Trevor L.; Acciavatti, Raymond J.; Kwon, Young Joon; Maidment, Andrew D. A.

2016-03-01

Multiplanar reconstruction (MPR) in digital breast tomosynthesis (DBT) allows tomographic images to be portrayed in various orientations. We have conducted research to determine the resolution of tomosynthesis MPR. We built a phantom that houses a star test pattern to measure resolution. This phantom provides three rotational degrees of freedom. The design consists of two hemispheres with longitudinal and latitudinal grooves that reference angular increments. When joined together, the hemispheres form a dome that sits inside a cylindrical encasement. The cylindrical encasement contains reference notches to match the longitudinal and latitudinal grooves that guide the phantom's rotations. With this design, any orientation of the star-pattern can be analyzed. Images of the star-pattern were acquired using a DBT mammography system at the Hospital of the University of Pennsylvania. Images taken were reconstructed and analyzed by two different methods. First, the maximum visible frequency (in line pairs per millimeter) of the star test pattern was measured. Then, the contrast was calculated at a fixed spatial frequency. These analyses confirm that resolution decreases with tilt relative to the breast support. They also confirm that resolution in tomosynthesis MPR is dependent on object orientation. Current results verify that the existence of super-resolution depends on the orientation of the frequency; the direction parallel to x-ray tube motion shows super-resolution. In conclusion, this study demonstrates that the direction of the spatial frequency relative to the motion of the x-ray tube is a determinant of resolution in MPR for DBT.

Magnetic resonance imaging (MRI) of the renal sinus.

PubMed

Krishna, Satheesh; Schieda, Nicola; Flood, Trevor A; Shanbhogue, Alampady Krishna; Ramanathan, Subramaniyan; Siegelman, Evan

2018-04-09

This article presents methods to improve MR imaging approach of disorders of the renal sinus which are relatively uncommon and can be technically challenging. Multi-planar Single-shot T2-weighted (T2W) Fast Spin-Echo sequences are recommended to optimally assess anatomic relations of disease. Multi-planar 3D-T1W Gradient Recalled Echo imaging before and after Gadolinium administration depicts the presence and type of enhancement and relation to arterial, venous, and collecting system structures. To improve urographic phase MRI, concentrated Gadolinium in the collecting systems should be diluted. Diffusion-Weighted Imaging (DWI) should be performed before Gadolinium administration to minimize T2* effects. Renal sinus cysts are common but can occasionally be confused for dilated collecting system or calyceal diverticula, with the latter communicating with the collecting system and filling on urographic phase imaging. Vascular lesions (e.g., aneurysm, fistulas) may mimic cystic (or solid) lesions on non-enhanced MRI but can be suspected by noting similar signal intensity to the blood pool and diagnosis can be confirmed with MR angiogram/venogram. Multilocular cystic nephroma commonly extends to the renal sinus, however, to date are indistinguishable from cystic renal cell carcinoma (RCC). Solid hilar tumors are most commonly RCC and urothelial cell carcinoma (UCC). Hilar RCC are heterogeneous, hypervascular with epicenter in the renal cortex compared to UCC which are centered in the collecting system, homogeneously hypovascular, and show profound restricted diffusion. Diagnosis of renal sinus invasion in RCC is critically important as it is the most common imaging cause of pre-operative under-staging of disease. Fat is a normal component of the renal sinus; however, amount of sinus fat correlates with cardiovascular disease and is also seen in lipomatosis. Fat-containing hilar lesions include lipomas, angiomyolipomas, and less commonly other tumors which engulf sinus fat. Mesenchymal hilar tumors are rare. MR imaging diagnosis is generally not possible, although anatomic relations should be described to guide diagnosis by percutaneous biopsy or surgery.

Serial nonenhancing magnetic resonance imaging scans of high grade glioblastoma multiforme.

PubMed Central

Moore-Stovall, J.; Venkatesh, R.

1993-01-01

Magnetic resonance imaging (MRI) from clinical experience has proven to be superior to all other diagnostic imaging modalities, including computed tomography (CT) in the detection of intracranial neoplasms. Although glioblastoma multiforme presents a challenge for all diagnostic imaging modalities including MRI, MRI is paramount to CT in detecting subtle abnormal water accumulation in brain tissue caused by tumor even before there is disruption of the blood brain barrier. Currently, clinical research and investigational trials on nonionic gadolinium contrast agents have proven that nonionic gadolinium HP-DO3A (ProHance) contrast agents have lower osmolality and greater stability, which make them superior compounds to gadolinium diethylenetriamine-pentacetic acid (Gd-DTPA). Therefore, the nonionic gadolinium contrasts have been safely administered more rapidly, in higher or multiple doses for contrast enhanced MRI without adverse side effects or changes in serum iron or total bilirubin, and the intensity of the area of enhancement and number of lesions detected were superior to that of Gd-DTPA (Magnevist) at the standard dose (0.1 mmol/Kg). Perhaps if the nonionic gadolinium contrast agent, ProHance, had been approved by the Food and Drug Administration (FDA) when this MRI was performed in 1990 it would have aided in providing contrast enhancement and visualization of the tumor lesion to assist in patient diagnosis and management. Magnetic resonance imaging also provides unique multiplanar capabilities that allow for optimal visualization of the temporal and occipital lobes of the brain without bone interference.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9A Figure 9B Figure 10 Figure 11 Figure 12 Figure 13 PMID:8382751

Real time coarse orientation detection in MR scans using multi-planar deep convolutional neural networks

NASA Astrophysics Data System (ADS)

Bhatia, Parmeet S.; Reda, Fitsum; Harder, Martin; Zhan, Yiqiang; Zhou, Xiang Sean

2017-02-01

Automatically detecting anatomy orientation is an important task in medical image analysis. Specifically, the ability to automatically detect coarse orientation of structures is useful to minimize the effort of fine/accurate orientation detection algorithms, to initialize non-rigid deformable registration algorithms or to align models to target structures in model-based segmentation algorithms. In this work, we present a deep convolution neural network (DCNN)-based method for fast and robust detection of the coarse structure orientation, i.e., the hemi-sphere where the principal axis of a structure lies. That is, our algorithm predicts whether the principal orientation of a structure is in the northern hemisphere or southern hemisphere, which we will refer to as UP and DOWN, respectively, in the remainder of this manuscript. The only assumption of our method is that the entire structure is located within the scan's field-of-view (FOV). To efficiently solve the problem in 3D space, we formulated it as a multi-planar 2D deep learning problem. In the training stage, a large number coronal-sagittal slice pairs are constructed as 2-channel images to train a DCNN to classify whether a scan is UP or DOWN. During testing, we randomly sample a small number of coronal-sagittal 2-channel images and pass them through our trained network. Finally, coarse structure orientation is determined using majority voting. We tested our method on 114 Elbow MR Scans. Experimental results suggest that only five 2-channel images are sufficient to achieve a high success rate of 97.39%. Our method is also extremely fast and takes approximately 50 milliseconds per 3D MR scan. Our method is insensitive to the location of the structure in the FOV.

Usefulness of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI): assessment of morphology and diameter of the superior mesenteric artery (SMA) on multi-planar reconstructed (MPR) images.

PubMed

Woodhams, Reiko; Nishimaki, Hiroshi; Fujii, Kaoru; Kakita, Satoko; Hayakawa, Kazushige

2010-10-01

The purpose of this study was to assess the efficacy of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI) by analyzing morphology and diameter of superior mesenteric artery (SMA). We assessed whether MDCT was as useful as angiography for the diagnosis of NOMI. Four patients who were diagnosed with NOMI were retrospectively analyzed. All patients had 8-row MDCT followed by laparotomy. Two of them underwent angiography after MDCT. The morphology and diameter of SMA of these cases was analyzed on multi-planar reconstructed (MPR) images. The mean diameter of SMA of NOMI cases was compared to that of 13 control cases. MPR images of all NOMI cases showed irregular narrowing of the SMA, spasm of the arcades of SMA, and poor demonstration of intramural vessels. MPR images of two patients who had angiography were concordant with their angiograms. The mean diameter of SMA of NOMI patients was 3.4±1.1mm, which was statistically smaller than that of 13 control patients, 6.0±1.5mm (P<0.05, Wilcoxon rank sum tests). Angiography has been recognized essential for the diagnosis of NOMI. This study shows the possibility of MDCT to be an equivalently useful modality compared to angiography for the diagnosis of NOMI by interpreting morphologic appearance and diameter of SMA. Introduction of MDCT in the decision tree of NOMI treatment may bring the benefit of prompt diagnosis and subsequent early and efficient initiation of therapy, which may improve the mortality. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

CT measurements of central pulmonary vasculature as predictors of severe exacerbation in COPD

PubMed Central

Rho, Ji Young; Lynch, David A.; Suh, Young Ju; Nah, Jeung Weon; Zach, Jordan A.; Schroeder, Joyce D.; Cox, Christian W.; Bowler, Russell P.; Fenster, Brett E.; Dransfield, Mark T.; Wells, James M.; Hokanson, John E.; Curran-Everett, Douglas; Williams, Andre; Han, MeiLan K.; Crapo, James D.; Silverman, Edwin K.

2018-01-01

Abstract To identify a predictive value for the exacerbation status of chronic obstructive pulmonary disease (COPD) subjects, we evaluated the relationship between pulmonary vascular measurements on chest CT and severe COPD exacerbation. Six hundred three subjects enrolled in the COPDGene population were included and divided into nonexacerbator (n = 313) and severe exacerbator (n = 290) groups, based on whether they had an emergency room visit and/or hospitalization for COPD exacerbation. We measured the diameter of the main pulmonary artery (MPA) and ascending aorta (AA) at 2 different sites of the MPA (the tubular midportion and bifurcation) on both axial images and multiplanar reconstructions. Using multiple logistic regression analyses, we evaluated the relationship between each CT-measured pulmonary vasculature and exacerbation status. Axial and multiplanar MPA to AA diameter ratios (PA:AA ratios) at the tubular midportion and the axial PA:AA ratios at the bifurcation indicated significant association with severe exacerbation. The strongest association was found with the axial PA:mean AA ratio at the bifurcation (adjusted odds ratio [OR] = 12.53, 95% confidence interval [CI] = 2.35–66.74, P = .003) and the axial PA:major AA ratio at the tubular midportion (adjusted OR = 10.72, 95% CI = 1.99–57.86, P = .006). No differences were observed in the MPA diameter. Receiver operating characteristic analysis of these variables indicates that they may serve as a good predictive value for severe exacerbation (area under the curve, 0.77–0.78). The range of cut-off value for PA:AA ratio was 0.8 to 0.87. CT-measured PA:AA ratios at either the bifurcation or the tubular site, measured either on axial or multiplanar images, are useful for identification of the risk of severe exacerbation, and consequently can be helpful in guiding the management of COPD. Although CT measurement was used at the level of pulmonary bifurcation in previous studies, we suggest that future studies should monitor the tubular site of the MPA for maximum diagnostic value of CT in pulmonary hypertension or severe COPD exacerbation, as the tubular site of the MPA remains relatively constant on CT images. PMID:29504975

CT measurements of central pulmonary vasculature as predictors of severe exacerbation in COPD.

PubMed

Rho, Ji Young; Lynch, David A; Suh, Young Ju; Nah, Jeung Weon; Zach, Jordan A; Schroeder, Joyce D; Cox, Christian W; Bowler, Russell P; Fenster, Brett E; Dransfield, Mark T; Wells, James M; Hokanson, John E; Curran-Everett, Douglas; Williams, Andre; Han, MeiLan K; Crapo, James D; Silverman, Edwin K

2018-01-01

To identify a predictive value for the exacerbation status of chronic obstructive pulmonary disease (COPD) subjects, we evaluated the relationship between pulmonary vascular measurements on chest CT and severe COPD exacerbation.Six hundred three subjects enrolled in the COPDGene population were included and divided into nonexacerbator (n = 313) and severe exacerbator (n = 290) groups, based on whether they had an emergency room visit and/or hospitalization for COPD exacerbation. We measured the diameter of the main pulmonary artery (MPA) and ascending aorta (AA) at 2 different sites of the MPA (the tubular midportion and bifurcation) on both axial images and multiplanar reconstructions. Using multiple logistic regression analyses, we evaluated the relationship between each CT-measured pulmonary vasculature and exacerbation status.Axial and multiplanar MPA to AA diameter ratios (PA:AA ratios) at the tubular midportion and the axial PA:AA ratios at the bifurcation indicated significant association with severe exacerbation. The strongest association was found with the axial PA:mean AA ratio at the bifurcation (adjusted odds ratio [OR] = 12.53, 95% confidence interval [CI] = 2.35-66.74, P = .003) and the axial PA:major AA ratio at the tubular midportion (adjusted OR = 10.72, 95% CI = 1.99-57.86, P = .006). No differences were observed in the MPA diameter. Receiver operating characteristic analysis of these variables indicates that they may serve as a good predictive value for severe exacerbation (area under the curve, 0.77-0.78). The range of cut-off value for PA:AA ratio was 0.8 to 0.87.CT-measured PA:AA ratios at either the bifurcation or the tubular site, measured either on axial or multiplanar images, are useful for identification of the risk of severe exacerbation, and consequently can be helpful in guiding the management of COPD. Although CT measurement was used at the level of pulmonary bifurcation in previous studies, we suggest that future studies should monitor the tubular site of the MPA for maximum diagnostic value of CT in pulmonary hypertension or severe COPD exacerbation, as the tubular site of the MPA remains relatively constant on CT images. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Magnetic resonance imaging in neuropsychiatric systemic lupus erythematosus: current state of the art and novel approaches.

PubMed

Postal, M; Lapa, A Tamires; Reis, F; Rittner, L; Appenzeller, S

2017-04-01

Systemic lupus erythematosus is a chronic, inflammatory, immune-mediated disease affecting 0.1% of the general population. Neuropsychiatric manifestations in systemic lupus erythematosus have been more frequently recognized and reported in recent years, occurring in up to 75% of patients during the disease course. Magnetic resonance imaging is known to be a useful tool for the detection of structural brain abnormalities in neuropsychiatric systemic lupus erythematosus patients because of the excellent soft-tissue contrast observed with MRI and the ability to acquire multiplanar images. In addition to conventional magnetic resonance imaging techniques to evaluate the presence of atrophy and white matter lesions, several different magnetic resonance imaging techniques have been used to identify microstructural or functional abnormalities. This review will highlight different magnetic resonance imaging techniques, including the advanced magnetic resonance imaging methods used to determine central nervous system involvement in systemic lupus erythematosus.

Contrast-enhanced computed tomography of the gastrointestinal tract in clinically normal alpacas and llamas.

PubMed

Stieger-Vanegas, Susanne M; Cebra, Christopher K

2013-01-15

To assess the feasibility and usefulness of CT enterography to evaluate the gastrointestinal tract in clinically normal llamas and alpacas. Prospective observational study. 7 clinically normal alpacas and 8 clinically normal llamas. The imaging protocol included orogastric administration of iodinated contrast material mixed with water. Three hours later, helical CT scanning was performed of the entire abdomen with transverse and multiplanar sagittal and dorsal projections before and after IV iodinated contrast agent injection. Both oral and IV contrast agents were well tolerated, and no adverse reactions were observed. Transverse images depicted the gastrointestinal tract and pancreas in the short axis; however, dorsal and sagittal projections aided in localizing and differentiating the various gastrointestinal segments, including the pancreas. In all camelids, the wall of the gastrointestinal tract was well differentiated. In all but 2 camelids, all gastrointestinal segments were well visualized and differentiated. In those 2 animals, the cecum was difficult to identify. Good distention of the small intestine was achieved by use of the oral contrast agent. The dorsal projections were useful to identify the pancreas in its entire length. The present study supplied new information about gastrointestinal wall thickness, intestinal diameter, and location of the pancreas and ileocecocolic junction in alpacas and llamas. Multiplanar contrast-enhanced CT was useful to reveal the various segments of the gastrointestinal tract, pancreas, and abdominal lymph nodes. The shorter time delay before imaging, compared with the delay with conventional barium studies, makes this technique complementary or superior to conventional radiographic or ultrasonographic studies for evaluation of the gastrointestinal tract.

Image quality metrics for volumetric laser displays

NASA Astrophysics Data System (ADS)

Williams, Rodney D.; Donohoo, Daniel

1991-08-01

This paper addresses the extensions to the image quality metrics and related human factors research that are needed to establish the baseline standards for emerging volume display technologies. The existing and recently developed technologies for multiplanar volume displays are reviewed with an emphasis on basic human visual issues. Human factors image quality metrics and guidelines are needed to firmly establish this technology in the marketplace. The human visual requirements and the display design tradeoffs for these prototype laser-based volume displays are addressed and several critical image quality issues identified for further research. The American National Standard for Human Factors Engineering of Visual Display Terminal Workstations (ANSIHFS-100) and other international standards (ISO, DIN) can serve as a starting point, but this research base must be extended to provide new image quality metrics for this new technology for volume displays.

Assessment of the cochlear nerve to facial nerve size ratio using MR multiplanar reconstruction of the internal auditory canal in patients presenting with acquired long-standing hearing loss

PubMed Central

Hey, Constanze; Shaaban, Mohamed S; Elabd, Amr M; Hassan, Hebatallah H M; Gruber-Rouh, Tatjana; Kaltenbach, Benjamin; Harth, Marc; Ackermann, Hanns; Stöver, Timo; Vogl, Thomas J; Nour-Eldin, Nour-Eldin A

2017-01-01

Objective: To test using the facial nerve as a reference for assessment of the cochlear nerve size in patients with acquired long-standing sensorineural hearing loss (SNHL) using MRI multiplanar reconstruction. Methods: The study was retrospectively performed on 86 patients. Group 1 (study group, n = 53) with bilateral long-standing SNHL. Group 2 (control group, n = 33) without hearing loss. The nerve size was measured by drawing a region of interest around the cross-sectional circumference of the nerve in multiplanar reconstruction images. Results: No significant correlation was noted between the cochlear nerve and facial nerve size, and the patient's age, gender and weight (p > 0.05). In Group 1, the mean ratio of the cochlear to facial nerve size was 0.99 ± 0.30 (range: 0.52–1.86) and 1.12 ± 0.35 (range: 0.34–2.3) for the right and left sides, respectively. In Group 2, it was 1.18 ± 0.23 (range: 0.78–1.71) and 1.25 ± 0.25 (range: 0.85–1.94) for the right and left sides, respectively. The cochlear nerve size was statistically (p = 0.0004) smaller in Group 1 than in Group 2. Conclusion: The cochlear nerve size and the cochlear to facial nerve size ratio are significantly smaller in patients with acquired long-standing SNHL. Advances in knowledge: The facial nerve can be used as a reference for assessment of the cochlear nerve in patients with acquired long-standing SNHL. PMID:28368665

Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

PubMed Central

Ippolito, Davide; Drago, Silvia Girolama; Franzesi, Cammillo Talei; Fior, Davide; Sironi, Sandro

2016-01-01

AIM: To assess the diagnostic accuracy of multidetector-row computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images, as compared to the reference magnetic resonance images. The difference in accuracy was statistically significant (P = 0.02). CONCLUSION: New generation CT scanner, using high resolution MPR images, represents a reliable diagnostic tool in assessment of loco-regional and whole body staging of advanced rectal cancer, especially in patients with MRI contraindications. PMID:27239115

A comparison and update of direct kinematic-kinetic models of leg stiffness in human running.

PubMed

Liew, Bernard X W; Morris, Susan; Masters, Ashleigh; Netto, Kevin

2017-11-07

Direct kinematic-kinetic modelling currently represents the "Gold-standard" in leg stiffness quantification during three-dimensional (3D) motion capture experiments. However, the medial-lateral components of ground reaction force and leg length have been neglected in current leg stiffness formulations. It is unknown if accounting for all 3D would alter healthy biologic estimates of leg stiffness, compared to present direct modelling methods. This study compared running leg stiffness derived from a new method (multiplanar method) which includes all three Cartesian axes, against current methods which either only include the vertical axis (line method) or only the plane of progression (uniplanar method). Twenty healthy female runners performed shod overground running at 5.0 m/s. Three-dimensional motion capture and synchronised in-ground force plates were used to track the change in length of the leg vector (hip joint centre to centre of pressure) and resultant projected ground reaction force. Leg stiffness was expressed as dimensionless units, as a percentage of an individual's bodyweight divided by standing leg length (BW/LL). Leg stiffness using the line method was larger than the uniplanar method by 15.6%BW/LL (P < .001), and multiplanar method by 24.2%BW/LL (P < .001). Leg stiffness from the uniplanar method was larger than the multiplanar method by 8.5%BW/LL (6.5 kN/m) (P < .001). The inclusion of medial-lateral components significantly increased leg deformation magnitude, accounting for the reduction in leg stiffness estimate with the multiplanar method. Given that limb movements typically occur in 3D, the new multiplanar method provides the most complete accounting of all force and length components in leg stiffness calculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Imaging of Sports-Related Hip and Groin Injuries

PubMed Central

Lischuk, Andrew W.; Dorantes, Thomas M.; Wong, William; Haims, Andrew H.

2010-01-01

A normally functioning hip joint is imperative for athletes who use their lower extremities with running, jumping, or kicking activities. Sports-related injuries of the hip and groin are far less frequent than injuries to the more distal aspect of the extremity, accounting for less than 10% of lower extremity injuries. Despite the lower incidence, hip and groin injuries can lead to significant clinical and diagnostic challenges related to the complex anatomy and biomechanical considerations of this region. Loads up to 8 times normal body weight have been documented in the joint in common daily activities, such as jogging, with significantly greater force expected during competitive athletics. Additionally, treatment for hip and groin injuries can obviate the participation of medical and surgical specialties, with a multidisciplinary approach frequently required. Delay in diagnosis and triage of these injuries may cause loss of time from competition and, potentially, early onset of degenerative changes. Magnetic resonance imaging (MRI) of the hip has proven to be the gold standard for the diagnosis of sports-related hip and groin injuries in the setting of negative radiographs. With its exquisite soft tissue contrast, multiplanar capabilities, and lack of ionizing radiation, MRI is unmatched in the noninvasive diagnosis of intra-articular and extra-articular pathology, as well as intraosseous processes. This review focuses on MRI of common athletic injuries of the hip and groin, including acetabular labral tears, femoral acetabular impingement syndrome, muscle injuries around the hip and groin (including athletic pubalgia), and athletic osseous injuries. PMID:23015946

Imaging of sports-related hip and groin injuries.

PubMed

Lischuk, Andrew W; Dorantes, Thomas M; Wong, William; Haims, Andrew H

2010-05-01

A normally functioning hip joint is imperative for athletes who use their lower extremities with running, jumping, or kicking activities. Sports-related injuries of the hip and groin are far less frequent than injuries to the more distal aspect of the extremity, accounting for less than 10% of lower extremity injuries. Despite the lower incidence, hip and groin injuries can lead to significant clinical and diagnostic challenges related to the complex anatomy and biomechanical considerations of this region. Loads up to 8 times normal body weight have been documented in the joint in common daily activities, such as jogging, with significantly greater force expected during competitive athletics. Additionally, treatment for hip and groin injuries can obviate the participation of medical and surgical specialties, with a multidisciplinary approach frequently required. Delay in diagnosis and triage of these injuries may cause loss of time from competition and, potentially, early onset of degenerative changes. Magnetic resonance imaging (MRI) of the hip has proven to be the gold standard for the diagnosis of sports-related hip and groin injuries in the setting of negative radiographs. With its exquisite soft tissue contrast, multiplanar capabilities, and lack of ionizing radiation, MRI is unmatched in the noninvasive diagnosis of intra-articular and extra-articular pathology, as well as intraosseous processes. This review focuses on MRI of common athletic injuries of the hip and groin, including acetabular labral tears, femoral acetabular impingement syndrome, muscle injuries around the hip and groin (including athletic pubalgia), and athletic osseous injuries.

Kinematic reconstruction in cardiovascular imaging.

PubMed

Bastarrika, G; Huebra Rodríguez, I J González de la; Calvo-Imirizaldu, M; Suárez Vega, V M; Alonso-Burgos, A

2018-05-17

Advances in clinical applications of computed tomography have been accompanied by improvements in advanced post-processing tools. In addition to multiplanar reconstructions, curved planar reconstructions, maximum intensity projections, and volumetric reconstructions, very recently kinematic reconstruction has been developed. This new technique, based on mathematical models that simulate the propagation of light beams through a volume of data, makes it possible to obtain very realistic three dimensional images. This article illustrates examples of kinematic reconstructions and compares them with classical volumetric reconstructions in patients with cardiovascular disease in a way that makes it easy to establish the differences between the two types of reconstruction. Kinematic reconstruction is a new method for representing three dimensional images that facilitates the explanation and comprehension of the findings. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

[The clinical and X-ray classification of osteonecrosis of the low jaw].

PubMed

Medvedev, Iu A; Basin, E M; Sokolina, I A

2013-01-01

To elaborate a clinical and X-ray classification of osteonecrosis of the low jaw in people with desomorphine or pervitin addiction. Ninety-two patients with drug addiction who had undergone orthopantomography, direct frontal X-ray of the skull, and multislice computed tomography, followed by multiplanar and three-dimensional imaging reconstruction were examined. One hundred thirty four X-ray films and 74 computed tomographic images were analyzed. The authors proposed a clinical and X-ray classification of osteonecrosis of the low jaw in people with desomorphine or pervitin addiction and elaborated recommendations for surgical interventions on the basis of the developed classification. The developed clinical and X-ray classification and recommendations for surgical interventions may be used to treat osteonecroses of various etiology.

Evaluation of Rib Fractures on a Single-in-plane Image Reformation of the Rib Cage in CT Examinations.

PubMed

Dankerl, Peter; Seuss, Hannes; Ellmann, Stephan; Cavallaro, Alexander; Uder, Michael; Hammon, Matthias

2017-02-01

This study aimed to evaluate the diagnostic performance of using a reformatted single-in-plane image reformation of the rib cage for the detection of rib fractures in computed tomography (CT) examinations, employing different levels of radiological experience. We retrospectively evaluated 10 consecutive patients with and 10 patients without rib fractures, whose CT scans were reformatted to a single-in-plane image reformation of the rib cage. Eight readers (two radiologists, two residents in radiology, and four interns) independently evaluated the images for the presence of rib fractures using a reformatted single-in-plane image and a multi-planar image reformation. The time limit was 30 seconds for each read. A consensus of two radiologist readings was considered as the reference standard. Diagnostic performance (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) was assessed and evaluated per rib and per location (anterior, lateral, posterior). To determine the time limit, we prospectively analyzed the average time it took radiologists to assess the rib cage, in a bone window setting, in 50 routine CT examinations. McNemar test was used to compare the diagnostic performances. Single image reformation was successful in all 20 patients. The sensitivity, specificity, PPV, and NPV for the detection of rib fractures using the conventional multi-planar read were 77.5%, 99.2%, 89.9%, and 98.0% for radiologists; 46.3%, 99.7%, 92.5%, and 95.3% for residents; and 29.4%, 99.4%, 82.5%, and 93.9% for interns, respectively. Sensitivity, PPV, and NPV increased across all three groups of experience, using the reformatted single-in-plane image of the rib cage (radiologists: 85.0%, 98.6%, and 98.7%; residents: 80.0%, 92.8%, and 98.2%; interns: 66.9%, 89.9%, and 97.1%), whereas specificity did not change significantly (99.9%, 99.4%, and 99.3%). The diagnostic performance of the interns and residents was significantly better when evaluating the single-in-plane image reformations (P < .01). The diagnostic performance of the radiologists was better when evaluating the single-in-plane image reformations; however, there was no significant difference (statistical power: 0.32). The diagnostic performance for the detection of rib fractures, using CT images that have been reformatted to a single-in-plane image, improves for readers from different educational levels when the evaluation time is restricted to 30 seconds or less. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Clinical Application of Cone Beam Computed Tomography of the Rabbit Head: Part 2—Dental Disease

PubMed Central

Riggs, G. G.; Cissell, Derek D.; Arzi, Boaz; Hatcher, David C.; Kass, Philip H.; Zhen, Amy; Verstraete, Frank J. M.

2017-01-01

Domestic rabbits are increasing in popularity as household pets; therefore, veterinarians need to be familiar with the most common diseases afflicting rabbits including dental disease. Current diagnostic approaches include gross oral examination, endoscopic oral examination, skull radiography, and computed tomography (CT). Cone beam computed tomography (CBCT), a new oral and maxillofacial imaging modality that has the capability to produce high-resolution images, has not yet been described for use in evaluating dental disease in rabbits. A total of 15 client-owned rabbits had CBCT, oral examination, dental charting, and dental treatment performed under general anesthesia. Images were evaluated using transverse and custom multiplanar (MPR), 3D, and panoramic reconstructed images. The CBCT findings were grouped into abnormalities that could be detected on conscious oral examination vs. abnormalities that could not be detected by conscious oral examination. Potential associations between the two categories were examined by pairwise Fisher’s exact test with statistical significance determined by P < 0.05. The most common findings identified on CBCT images were periodontal ligament space widening (14/15), premolar and molar malocclusion (13/15), apical elongation (13/15), coronal elongation (12/15), inflammatory tooth resorption (12/15), periapical lucency (11/15), moth-eaten pattern of osteolysis of the alveolar bone (9/15), ventral mandibular border contour changes (9/15), and missing teeth (8/15). Of the CBCT abnormalities likely to be observed on oral examination, coronal elongation (detectable on oral examination) was significantly associated with apical elongation (P = 0.029). There were no other significant associations between CBCT findings that are also clinically detectable and CBCT findings that are not be detectable on oral examination. This suggests that pathology often exists that is not apparent upon oral examination. This study establishes the common CBCT findings associated with dental disease in rabbits and demonstrates the feasibility of this technology to diagnose and plan treatment in dental disorders in this species. PMID:28194401

Strain Response of the Anterior Cruciate Ligament to Uniplanar and Multiplanar Loads During Simulated Landings: Implications for Injury Mechanism.

PubMed

Kiapour, Ata M; Demetropoulos, Constantine K; Kiapour, Ali; Quatman, Carmen E; Wordeman, Samuel C; Goel, Vijay K; Hewett, Timothy E

2016-08-01

Despite basic characterization of the loading factors that strain the anterior cruciate ligament (ACL), the interrelationship(s) and additive nature of these loads that occur during noncontact ACL injuries remain incompletely characterized. In the presence of an impulsive axial compression, simulating vertical ground-reaction force during landing (1) both knee abduction and internal tibial rotation moments would result in increased peak ACL strain, and (2) a combined multiplanar loading condition, including both knee abduction and internal tibial rotation moments, would increase the peak ACL strain to levels greater than those under uniplanar loading modes alone. Controlled laboratory study. A cadaveric model of landing was used to simulate dynamic landings during a jump in 17 cadaveric lower extremities (age, 45 ± 7 years; 9 female and 8 male). Peak ACL strain was measured in situ and characterized under impulsive axial compression and simulated muscle forces (baseline) followed by addition of anterior tibial shear, knee abduction, and internal tibial rotation loads in both uni- and multiplanar modes, simulating a broad range of landing conditions. The associations between knee rotational kinematics and peak ACL strain levels were further investigated to determine the potential noncontact injury mechanism. Externally applied loads, under both uni- and multiplanar conditions, resulted in consistent increases in peak ACL strain compared with the baseline during simulated landings (by up to 3.5-fold; P ≤ .032). Combined multiplanar loading resulted in the greatest increases in peak ACL strain (P < .001). Degrees of knee abduction rotation (R(2) = 0.45; β = 0.42) and internal tibial rotation (R(2) = 0.32; β = 0.23) were both significantly correlated with peak ACL strain (P < .001). However, changes in knee abduction rotation had a significantly greater effect size on peak ACL strain levels than did internal tibial rotation (by ~2-fold; P < .001). In the presence of impulsive axial compression, the combination of anterior tibial shear force, knee abduction, and internal tibial rotation moments significantly increases ACL strain, which could result in ACL failure. These findings support multiplanar knee valgus collapse as one the primary mechanisms of noncontact ACL injuries during landing. Intervention programs that address multiple planes of loading may decrease the risk of ACL injury and the devastating consequences of posttraumatic knee osteoarthritis. © 2016 The Author(s).

Multi-planar bending properties of lumbar intervertebral joints following cyclic bending.

PubMed

Chow, Daniel H K; Luk, Keith D K; Holmes, Andrew D; Li, Xing-Fei; Tam, Steven C W

2004-02-01

To assess the changes in the multi-planar bending properties of intervertebral joints following cyclic bending along different directions. An in vitro biomechanical study using porcine lumbar motion segments. Repeated bending has been suggested as part of the etiology of gradual prolapse of the intervertebral disc, but the multi-planar changes in bending properties following cyclic loading have not been examined in detail. Porcine lumbar motion segments were subject to 1500 cycles of bending along directions of 0 degrees (flexion), 30 degrees, 60 degrees, or 90 degrees (right lateral bending). The multi-planar bending moments and hysteresis energies were recorded before loading and after various cycle numbers. Repeated bending at 30 degrees and 60 degrees resulted in greater decreases in mean bending moment and hysteresis energy than bending at 0 degrees or 90 degrees. No significant differences were seen between loading groups for the change in bending moment along the anterior testing directions, but significant differences were observed in the posterior and lateral testing directions, with bending at 30 degrees causing a significantly greater decrease in bending moment in the postero-lateral directions. The change in mechanical properties of porcine intervertebral joints due to cyclic bending depend on the direction of loading and the direction in which the properties are measured. Loading at 30 degrees provokes the most marked changes in bending moment and hysteresis energy.

Cone beam computed tomography in veterinary dentistry.

PubMed

Van Thielen, Bert; Siguenza, Francis; Hassan, Bassam

2012-01-01

The purpose of this study was to assess the feasibility of cone beam computed tomography (CBCT) in imaging dogs and cats for diagnostic dental veterinary applications. CBCT scans of heads of six dogs and two cats were made. Dental panoramic and multi-planar reformatted (MPR) para-sagittal reconstructions were created using specialized software. Image quality and visibility of anatomical landmarks were subjectively assessed by two observers. Good image quality was obtained for the MPR para-sagittal reconstructions through multiple teeth. The image quality of the panoramic reconstructions of dogs was moderate while the panoramic reconstructions of cats were poor since the images were associated with an increased noise level. Segmental panoramic reconstructions of the mouth seem to be useful for studying the dental anatomy especially in dogs. The results of this study using human dental CBCT technology demonstrate the potential of this scanning technology in veterinary medicine. Unfortunately, the moderate image quality obtained with the CBCT technique reported here seems to be inferior to the diagnostic image quality obtained from 2-dimensional dental radiographs. Further research is required to optimize scanning and reconstruction protocols for veterinary applications.

MR imaging of peripheral nervous system involvement: Parsonage-Turner syndrome.

PubMed

Zara, Gabriella; Gasparotti, Roberto; Manara, Renzo

2012-04-15

A 55-year-old woman complained of right scapular pain, like burning, radiating down his right arm and numbness in the first three fingers of the hand. Neurologic examination showed a slight deficit of the right brachial triceps muscle. Neurophysiological assessment showed a mild involvement of the seventh right spinal root (C7). Conventional MR imaging of the cervical spine showed mild disc protrusion at level C5-C6 without spinal root compression. High resolution MR neurography with multiplanar reconstruction along the course of the right brachial plexus showed a mild increase in signal intensity and thickening of the C7 root, middle trunk and posterior cord, consistent with Parsonage-Turner Syndrome. STIR images showed increased signal intensity in the right infraspinatus muscle innervated by the suprascapular nerve. In our case, sensitivity and specificity of the new MR sequences are higher than the clinical and neurophysiological evaluations. Copyright © 2011 Elsevier B.V. All rights reserved.

Simplifying the exploration of volumetric images: development of a 3D user interface for the radiologist's workplace.

PubMed

Teistler, M; Breiman, R S; Lison, T; Bott, O J; Pretschner, D P; Aziz, A; Nowinski, W L

2008-10-01

Volumetric imaging (computed tomography and magnetic resonance imaging) provides increased diagnostic detail but is associated with the problem of navigation through large amounts of data. In an attempt to overcome this problem, a novel 3D navigation tool has been designed and developed that is based on an alternative input device. A 3D mouse allows for simultaneous definition of position and orientation of orthogonal or oblique multiplanar reformatted images or slabs, which are presented within a virtual 3D scene together with the volume-rendered data set and additionally as 2D images. Slabs are visualized with maximum intensity projection, average intensity projection, or standard volume rendering technique. A prototype has been implemented based on PC technology that has been tested by several radiologists. It has shown to be easily understandable and usable after a very short learning phase. Our solution may help to fully exploit the diagnostic potential of volumetric imaging by allowing for a more efficient reading process compared to currently deployed solutions based on conventional mouse and keyboard.

Echocardiography in Infective Endocarditis: State of the Art.

PubMed

Afonso, Luis; Kottam, Anupama; Reddy, Vivek; Penumetcha, Anirudh

2017-10-25

In this review, we examine the central role of echocardiography in the diagnosis, prognosis, and management of infective endocarditis (IE). 2D transthoracic echocardiography (TTE) and transesophageal echocardiography TEE have complementary roles and are unequivocally the mainstay of diagnostic imaging in IE. The advent of 3D and multiplanar imaging have greatly enhanced the ability of the imager to evaluate cardiac structure and function. Technologic advances in 3D imaging allow for the reconstruction of realistic anatomic images that in turn have positively impacted IE-related surgical planning and intervention. CT and metabolic imaging appear to be emerging as promising ancillary diagnostic tools that could be deployed in select scenarios to circumvent some of the limitations of echocardiography. Our review summarizes the indispensable and central role of various echocardiographic modalities in the management of infective endocarditis. The complementary role of 2D TTE and TEE are discussed and areas where 3D TEE offers incremental value highlighted. An algorithm summarizing a contemporary approach to the workup of endocarditis is provided and major societal guidelines for timing of surgery are reviewed.

Use of cone beam computed tomography in periodontology

PubMed Central

Acar, Buket; Kamburoğlu, Kıvanç

2014-01-01

Diagnosis of periodontal disease mainly depends on clinical signs and symptoms. However, in the case of bone destruction, radiographs are valuable diagnostic tools as an adjunct to the clinical examination. Two dimensional periapical and panoramic radiographs are routinely used for diagnosing periodontal bone levels. In two dimensional imaging, evaluation of bone craters, lamina dura and periodontal bone level is limited by projection geometry and superpositions of adjacent anatomical structures. Those limitations of 2D radiographs can be eliminated by three-dimensional imaging techniques such as computed tomography. Cone beam computed tomography (CBCT) generates 3D volumetric images and is also commonly used in dentistry. All CBCT units provide axial, coronal and sagittal multi-planar reconstructed images without magnification. Also, panoramic images without distortion and magnification can be generated with curved planar reformation. CBCT displays 3D images that are necessary for the diagnosis of intra bony defects, furcation involvements and buccal/lingual bone destructions. CBCT applications provide obvious benefits in periodontics, however; it should be used only in correct indications considering the necessity and the potential hazards of the examination. PMID:24876918

Validity of multislice computerized tomography for diagnosis of maxillofacial fractures using an independent workstation.

PubMed

Dos Santos, Denise Takehana; Costa e Silva, Adriana Paula Andrade; Vannier, Michael Walter; Cavalcanti, Marcelo Gusmão Paraiso

2004-12-01

The purpose of this study was to demonstrate the sensitivity and specificity of multislice computerized tomography (CT) for diagnosis of maxillofacial fractures following specific protocols using an independent workstation. The study population consisted of 56 patients with maxillofacial fractures who were submitted to a multislice CT. The original data were transferred to an independent workstation using volumetric imaging software to generate axial images and simultaneous multiplanar (MPR) and 3-dimensional (3D-CT) volume rendering reconstructed images. The images were then processed and interpreted by 2 examiners using the following protocols independently of each other: axial, MPR/axial, 3D-CT images, and the association of axial/MPR/3D images. The clinical/surgical findings were considered the gold standard corroborating the diagnosis of the fractures and their anatomic localization. The statistical analysis was carried out using validity and chi-squared tests. The association of axial/MPR/3D images indicated a higher sensitivity (range 95.8%) and specificity (range 99%) than the other methods regarding the analysis of all regions. CT imaging demonstrated high specificity and sensitivity for maxillofacial fractures. The association of axial/MPR/3D-CT images added important information in relationship to other CT protocols.

Management of comminuted proximal ulna fracture-dislocations using a multiplanar locking intramedullary nail.

PubMed

Edwards, Scott G; Argintar, Evan; Lamb, Joshua

2011-06-01

Intramedullary nails have been used for the fixation of olecranon fractures in an attempt to reduce the soft tissue irritation and resulting need for hardware removal seen with plating and tension banding. Further benefits include preservation of vascular supply, and increase stability and improved compression over some alternative techniques. Most intramedullary nails have been limited to simple olecranon fractures or osteotomies. One novel multiplanar, locking intramedullary nail, however, is indicated to stabilize all fracture patterns of the proximal ulna, including the coronoid. This particular locking nail has screws that radiate in multiple planes and form a fixed-angle lattice throughout the bone. The nail also has fixed-angle screws dedicated to the 3 parts of the coronoid: process tip, medial facet, and medial wall. This allows the nail to secure multiple fragments regardless of the fracture pattern's extent of instability. The objective of this article is to illustrate the recommended steps in reducing and stabilizing a comminuted proximal ulna fracture-dislocation using this multiplanar locking intramedullary nail.

A multiplanar complex resection of a low-grade chondrosarcoma of the distal femur guided by K-wires previously inserted under CT-guide: a case report.

PubMed

Zoccali, Carmine; Rossi, Barbara; Ferraresi, Virginia; Anelli, Vincenzo; Rita, Alessandro

2014-08-13

In muscular skeletal oncology aiming to achieve wide surgical margin is one of the main factors influencing patient prognosis. In cases where lesions are either meta or epiphyseal, surgery most often compromises joint integrity and stability because muscles, tendons and ligaments are involved in wide resection. When lesions are well circumscribed they can be completely resected by performing multi-planar osteotomies guided by computer-assisted navigation. We describe a case of low-grade chondrosarcoma of the distal femur where a simple but effective technique was useful to perform complex multiplanar osteotomies. No similar techniques are reported in the literature. A 57 year-old Caucasian female was referred to our department for the presence of a distal femur chondrosarcoma. A resection with the presenting technique was scheduled. The first step consists of inserting several K-wires under CT-scan control to delimitate the tumor; the second step consists of tumor removal: in operative theatre, following surgical access, k-wires are used as guide positioning; scalpels are externally placed to k-wires to perform a safe osteotomy. Computed assisted resections can be considered the most advantageous method to reach the best surgical outcome; unfortunately navigation systems are only available in specialized centres. The present technique allows for a multiplanar complex resection when navigation systems are not available. This technique can be applied in low-grade tumours where a minimal wide margin can be considered sufficient.

Motor vehicle seat belt restraint system analysis during rollover.

PubMed

Meyer, Steven E; Hock, Davis; Forrest, Stephen; Herbst, Brian; Sances, Anthony; Kumaresan, Srirangam

2003-01-01

The multi-planar and multiple impact long duration accident sequence of a real world rollover results in multidirectional vehicle acceleration pulses and multiplanar occupant motions not typically seen in a planar crash sequence. Various researchers have documented that, while contemporary production emergency locking seatbelt retractors (ELRs) have been found to be extremely effective in the planar crashes in which they are extensively evaluated, when subjected to multi-planar acceleration environments their response may be different than expected. Specifically, accelerations in the vertical plane have been shown to substantially affect the timeliness of the retractors inertial sensor moving out of its neutral position and locking the seat belt. An analysis of the vehicle occupant motions relative to the acceleration pulses sensed at the retractor location indicates a time phase shift that, under certain circumstances, can result in unexpected seat belt spool out and occupant excursions in these multi-planar, multiple impact crash sequences. This paper will review the various previous studies focusing on the retractors response to these multidirectional, including vertical, acceleration environments and review statistical studies based upon U.S. government collected data indicating a significant difference in belt usage rates in rollover accidents as compared to all other planar accident modes. A significant number of real world accident case studies will be reviewed wherein the performance of ELR equipped seatbelt systems spooled out. Finally, the typical occupant injury and the associated mechanism due to belt spool out in real world accidents will be delineated.

Usefulness of biological fingerprint in magnetic resonance imaging for patient verification.

PubMed

Ueda, Yasuyuki; Morishita, Junji; Kudomi, Shohei; Ueda, Katsuhiko

2016-09-01

The purpose of our study is to investigate the feasibility of automated patient verification using multi-planar reconstruction (MPR) images generated from three-dimensional magnetic resonance (MR) imaging of the brain. Several anatomy-related MPR images generated from three-dimensional fast scout scan of each MR examination were used as biological fingerprint images in this study. The database of this study consisted of 730 temporal pairs of MR examination of the brain. We calculated the correlation value between current and prior biological fingerprint images of the same patient and also all combinations of two images for different patients to evaluate the effectiveness of our method for patient verification. The best performance of our system were as follows: a half-total error rate of 1.59 % with a false acceptance rate of 0.023 % and a false rejection rate of 3.15 %, an equal error rate of 1.37 %, and a rank-one identification rate of 98.6 %. Our method makes it possible to verify the identity of the patient using only some existing medical images without the addition of incidental equipment. Also, our method will contribute to patient misidentification error management caused by human errors.

Evaluation of the anterior ethmoidal artery by 3D dual volume rotational digital subtraction angiography and native multidetector CT with multiplanar reformations. Initial findings.

PubMed

Pandolfo, Ignazio; Vinci, Sergio; Salamone, Ignazio; Granata, Francesca; Mazziotti, Silvio

2007-06-01

Our purpose is to codify the anterior ethmoidal artery (AEA) course and its relationship with adjacent structures. Twenty patients with cerebrovascular disease underwent selective internal carotid dual volume angiography. Fusion of the vascular and bony images was obtained successively on a second console. MDCT of the cranium was performed in all patients. To identify the AEA course, multiplanar CT reformations were obtained. In all cases the entry-point of AEA and its course were identified by means of dual volume angiography. The information was confirmed by MDCT. In a second phase, we studied another 78 patients affected by inflammatory disease and polyposis only by means of MDCT, in order to confirm the previous data obtained by comparison between angiography and MDCT. In this second phase, 110/156 vessels were indirectly detected by means of visualization of the ethmoidal entry point. In the remaining cases, AEA was directly shown due to integrity of the thin ethmoidal bone lamellae or bony canal. Dual volume angiography is essential to identify the course of the AEA (standard of reference for the interpretation of CT). In patients with benign rhinosinusal pathology, where invasivity techniques are not justified, MPR reconstructions were of pivotal importance in the evaluation of the course of the artery with particular reference to its relationship with the frontal recess.

High precision localization of intracerebral hemorrhage based on 3D MPR on head CT images

NASA Astrophysics Data System (ADS)

Sun, Jianyong; Hou, Xiaoshuai; Sun, Shujie; Zhang, Jianguo

2017-03-01

The key step for minimally invasive intracerebral hemorrhage surgery is precisely positioning the hematoma location in the brain before and during the hematoma surgery, which can significantly improves the success rate of puncture hematoma. We designed a 3D computerized surgical plan (CSP) workstation precisely to locate brain hematoma based on Multi-Planar Reconstruction (MPR) visualization technique. We used ten patients' CT/MR studies to verify our designed CSP intracerebral hemorrhage localization method. With the doctor's assessment and comparing with the results of manual measurements, the output of CSP WS for hematoma surgery is more precise and reliable than manual procedure.

Oral and Maxillofacial Anatomy.

PubMed

Sadrameli, Mitra; Mupparapu, Mel

2018-01-01

This article deals with identification and descriptions of intraoral and extraoral anatomy of the dental and maxillofacial structures. The anatomic landmarks are highlighted and described based on their radiographic appearance and their clinical significance is provided. Cone beam CT-based images are described in detail using the multiplanar reconstructions. The skull views are depicted via line diagrams in addition to their normal radiographic appearance to make identification of anatomic structures easier for clinicians. The authors cover most of the anatomic structures commonly noted via radiographs and their descriptions. This article serves as a clinician's guide to oral and maxillofacial radiographic anatomy. Copyright © 2017 Elsevier Inc. All rights reserved.

A multiplanar complex resection of a low-grade chondrosarcoma of the distal femur guided by K-wires previously inserted under CT-guide: a case report

PubMed Central

2014-01-01

Background In muscular skeletal oncology aiming to achieve wide surgical margin is one of the main factors influencing patient prognosis. In cases where lesions are either meta or epiphyseal, surgery most often compromises joint integrity and stability because muscles, tendons and ligaments are involved in wide resection. When lesions are well circumscribed they can be completely resected by performing multi-planar osteotomies guided by computer-assisted navigation. We describe a case of low-grade chondrosarcoma of the distal femur where a simple but effective technique was useful to perform complex multiplanar osteotomies. No similar techniques are reported in the literature. Case presentation A 57 year-old Caucasian female was referred to our department for the presence of a distal femur chondrosarcoma. A resection with the presenting technique was scheduled. The first step consists of inserting several K-wires under CT-scan control to delimitate the tumor; the second step consists of tumor removal: in operative theatre, following surgical access, k-wires are used as guide positioning; scalpels are externally placed to k-wires to perform a safe osteotomy. Conclusions Computed assisted resections can be considered the most advantageous method to reach the best surgical outcome; unfortunately navigation systems are only available in specialized centres. The present technique allows for a multiplanar complex resection when navigation systems are not available. This technique can be applied in low-grade tumours where a minimal wide margin can be considered sufficient. PMID:25123066

An MRI guided system for prostate laser ablation with treatment planning and multi-planar temperature monitoring

NASA Astrophysics Data System (ADS)

Xu, Sheng; Agarwal, Harsh; Bernardo, Marcelino; Seifabadi, Reza; Turkbey, Baris; Partanen, Ari; Negussie, Ayele; Glossop, Neil; Choyke, Peter; Pinto, Peter; Wood, Bradford J.

2016-03-01

Prostate cancer is often over treated with standard treatment options which impact the patients' quality of life. Laser ablation has emerged as a new approach to treat prostate cancer while sparing the healthy tissue around the tumor. Since laser ablation has a small treatment zone with high temperature, it is necessary to use accurate image guidance and treatment planning to enable full ablation of the tumor. Intraoperative temperature monitoring is also desirable to protect critical structures from being damaged in laser ablation. In response to these problems, we developed a navigation platform and integrated it with a clinical MRI scanner and a side firing laser ablation device. The system allows imaging, image guidance, treatment planning and temperature monitoring to be carried out on the same platform. Temperature sensing phantoms were developed to demonstrate the concept of iterative treatment planning and intraoperative temperature monitoring. Retrospective patient studies were also conducted to show the clinical feasibility of the system.

Evaluation of the marsh deer stifle joint by imaging studies and gross anatomy.

PubMed

Shigue, D A; Rahal, S C; Schimming, B C; Santos, R R; Vulcano, L C; Linardi, J L; Teixeira, C R

2015-12-01

This study aimed to evaluate the stifle joint of marsh deer using imaging studies and in comparison with gross anatomy. Ten hindlimbs from 5 marsh deer (Blastocerus dichotomus) were used. Radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed in each stifle joint. Two hindlimbs were dissected to describe stifle gross anatomy. The other limbs were sectioned in sagittal, dorsal or transverse planes. In the craniocaudal radiographic view, the lateral femoral condyle was broader than the medial femoral condyle. The femoral trochlea was asymmetrical. Subsequent multiplanar reconstruction revealed in the cranial view that the external surface of the patella was roughened, the medial trochlea ridge was larger than the lateral one, and the extensor fossa at the lateral condyle was next to the lateral ridge. The popliteal fossa was better visualized via the lateral view. Sagittal MRI images identified lateral and medial menisci, caudolateral and craniomedial bundles of cranial cruciate ligament, caudal cruciate ligament, patellar ligament and common extensor tendon. In conclusion, the marsh deer stifle presents some anatomical characteristics of the ovine stifle joint. © 2014 Blackwell Verlag GmbH.

Brain magnetic resonance imaging findings in young patients with hepatosplenic schistosomiasis mansoni without overt symptoms.

PubMed

Manzella, Adonis; Borba-Filho, Paulo; Brandt, Carlos T; Oliveira, Keyla

2012-06-01

The purpose of this study was to describe the brain magnetic resonance imaging (MRI) findings in young patients with hepatosplenic schistosomiasis mansoni without overt neurologic manifestations. This study included 34 young persons (age range = 9-25 years) with hepatosplenic schistosomiasis mansoni who had been previously treated. Patients were scanned on a 1.5-T system that included multiplanar pre-contrast and post-contrast sequences, and reports were completed by two radiologists after a consensus review. Twenty (58.8%) patients had MRI signal changes that were believed to be related to schistosomiasis mansoni. Twelve of the 20 patients had small focal hyperintensities on T2WI in the cerebral white matter, and eight patients had symmetric hyperintense basal ganglia on T1WI. There was a high frequency of brain MRI signal abnormalities in this series. Although not specific, these findings may be related to schistosomiasis.

Deblurring in digital tomosynthesis by iterative self-layer subtraction

NASA Astrophysics Data System (ADS)

Youn, Hanbean; Kim, Jee Young; Jang, SunYoung; Cho, Min Kook; Cho, Seungryong; Kim, Ho Kyung

2010-04-01

Recent developments in large-area flat-panel detectors have made tomosynthesis technology revisited in multiplanar xray imaging. However, the typical shift-and-add (SAA) or backprojection reconstruction method is notably claimed by a lack of sharpness in the reconstructed images because of blur artifact which is the superposition of objects which are out of planes. In this study, we have devised an intuitive simple method to reduce the blur artifact based on an iterative approach. This method repeats a forward and backward projection procedure to determine the blur artifact affecting on the plane-of-interest (POI), and then subtracts it from the POI. The proposed method does not include any Fourierdomain operations hence excluding the Fourier-domain-originated artifacts. We describe the concept of the self-layer subtractive tomosynthesis and demonstrate its performance with numerical simulation and experiments. Comparative analysis with the conventional methods, such as the SAA and filtered backprojection methods, is addressed.

Effectiveness of a Rapid Lumbar Spine MRI Protocol Using 3D T2-Weighted SPACE Imaging Versus a Standard Protocol for Evaluation of Degenerative Changes of the Lumbar Spine.

PubMed

Sayah, Anousheh; Jay, Ann K; Toaff, Jacob S; Makariou, Erini V; Berkowitz, Frank

2016-09-01

Reducing lumbar spine MRI scanning time while retaining diagnostic accuracy can benefit patients and reduce health care costs. This study compares the effectiveness of a rapid lumbar MRI protocol using 3D T2-weighted sampling perfection with application-optimized contrast with different flip-angle evolutions (SPACE) sequences with a standard MRI protocol for evaluation of lumbar spondylosis. Two hundred fifty consecutive unenhanced lumbar MRI examinations performed at 1.5 T were retrospectively reviewed. Full, rapid, and complete versions of each examination were interpreted for spondylotic changes at each lumbar level, including herniations and neural compromise. The full examination consisted of sagittal T1-weighted, T2-weighted turbo spin-echo (TSE), and STIR sequences; and axial T1- and T2-weighted TSE sequences (time, 18 minutes 40 seconds). The rapid examination consisted of sagittal T1- and T2-weighted SPACE sequences, with axial SPACE reformations (time, 8 minutes 46 seconds). The complete examination consisted of the full examination plus the T2-weighted SPACE sequence. Sensitivities and specificities of the full and rapid examinations were calculated using the complete study as the reference standard. The rapid and full studies had sensitivities of 76.0% and 69.3%, with specificities of 97.2% and 97.9%, respectively, for all degenerative processes. Rapid and full sensitivities were 68.7% and 66.3% for disk herniation, 85.2% and 81.5% for canal compromise, 82.9% and 69.1% for lateral recess compromise, and 76.9% and 69.7% for foraminal compromise, respectively. Isotropic SPACE T2-weighted imaging provides high-quality imaging of lumbar spondylosis, with multiplanar reformatting capability. Our SPACE-based rapid protocol had sensitivities and specificities for herniations and neural compromise comparable to those of the protocol without SPACE. This protocol fits within a 15-minute slot, potentially reducing costs and discomfort for a large subgroup of patients.

Location of Rotator Cuff Tear Initiation: A Magnetic Resonance Imaging Study of 191 Shoulders.

PubMed

Jeong, Jeung Yeol; Min, Seul Ki; Park, Keun Min; Park, Yong Bok; Han, Kwang Joon; Yoo, Jae Chul

2018-03-01

Degenerative rotator cuff tears (RCTs) are generally thought to originate at the anterior margin of the supraspinatus tendon. However, a recent ultrasonography study suggested that they might originate more posteriorly than originally thought, perhaps even from the isolated infraspinatus (ISP) tendon, and propagate toward the anterior supraspinatus. Hypothesis/Purpose: It was hypothesized that this finding could be reproduced with magnetic resonance imaging (MRI). The purpose was to determine the most common location of degenerative RCTs by using 3-dimensional multiplanar MRI reconstruction. It was assumed that the location of the partial-thickness tears would identify the area of the initiation of full-thickness tears. Cross-sectional study; Level of evidence, 3. A retrospective analysis was conducted including 245 patients who had RCTs (nearly full- or partial-thickness tears) at the outpatient department between January 2011 and December 2013. RCTs were measured on 3-dimensional multiplanar reconstruction MRI with OsiriX software. The width and distance from the biceps tendon to the anterior margin of the tear were measured on T2-weighted sagittal images. In a spreadsheet, columns of consecutive numbers represented the size of each tear (anteroposterior width) and their locations with respect to the biceps brachii tendon. Data were pooled to graphically represent the width and location of all tears. Frequency histograms of the columns were made to visualize the distribution of tears. The tears were divided into 2 groups based on width (group A, <10 mm; group B, <20 and ≥10 mm) and analyzed for any differences in location related to size. The mean width of all RCTs was 11.9 ± 4.1 mm, and the mean length was 11.1 ± 5.0 mm. Histograms showed the most common location of origin to be 9 to 10 mm posterior to the biceps tendon. The histograms of groups A and B showed similar tear location distributions, indicating that the region approximately 10 mm posterior to the biceps tendon is the most common site of tear initiation. These results demonstrate that degenerative RCTs most commonly originate from approximately 9 to 10 mm posterior to the biceps tendon.

Spatial 3D infrastructure: display-independent software framework, high-speed rendering electronics, and several new displays

NASA Astrophysics Data System (ADS)

Chun, Won-Suk; Napoli, Joshua; Cossairt, Oliver S.; Dorval, Rick K.; Hall, Deirdre M.; Purtell, Thomas J., II; Schooler, James F.; Banker, Yigal; Favalora, Gregg E.

2005-03-01

We present a software and hardware foundation to enable the rapid adoption of 3-D displays. Different 3-D displays - such as multiplanar, multiview, and electroholographic displays - naturally require different rendering methods. The adoption of these displays in the marketplace will be accelerated by a common software framework. The authors designed the SpatialGL API, a new rendering framework that unifies these display methods under one interface. SpatialGL enables complementary visualization assets to coexist through a uniform infrastructure. Also, SpatialGL supports legacy interfaces such as the OpenGL API. The authors" first implementation of SpatialGL uses multiview and multislice rendering algorithms to exploit the performance of modern graphics processing units (GPUs) to enable real-time visualization of 3-D graphics from medical imaging, oil & gas exploration, and homeland security. At the time of writing, SpatialGL runs on COTS workstations (both Windows and Linux) and on Actuality"s high-performance embedded computational engine that couples an NVIDIA GeForce 6800 Ultra GPU, an AMD Athlon 64 processor, and a proprietary, high-speed, programmable volumetric frame buffer that interfaces to a 1024 x 768 x 3 digital projector. Progress is illustrated using an off-the-shelf multiview display, Actuality"s multiplanar Perspecta Spatial 3D System, and an experimental multiview display. The experimental display is a quasi-holographic view-sequential system that generates aerial imagery measuring 30 mm x 25 mm x 25 mm, providing 198 horizontal views.

WE-EF-BRA-12: Magnetic Resonance- Guided High-Intensity Focused Ultrasound for Localized Ablation of Head and Neck Tissue Structures: A Feasibility Study in An Animal Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Partanen, A; Ellens, N; Noureldine, S

Purpose: High-intensity focused ultrasound (HIFU) ablation is feasible in the head and neck [1]. This study aims to expand upon these findings to assess the feasibility of treatment planning and monitoring via magnetic resonance imaging (MRI) guidance using a clinical MR-guided HIFU platform. Methods: Two 31 kg pigs were anaesthetized, shaved, and positioned prone on the HIFU table (Sonalleve, Philips Healthcare, Vantaa, Finland). The necks were acoustically coupled to the integrated transducer using gel pads and degassed water. MR imaging verified acoustic coupling and facilitated target selection in the thyroid and thymus. Targets were thermally ablated with 130–200 W ofmore » acoustic power over a period of 16 s at a frequency of 1.2 MHz while being monitored through real-time, multi-planar MR-thermometry. Contrast-enhanced MR imaging was used to assess treatment efficacy. Post-treatment, animals were euthanized and sonicated tissues were harvested for histology assessment. Results: MR-thermometry, post-contrast-imaging, and gross pathology demonstrated that the system was capable of causing localized thermal ablation in both the thyroid and the thymus without damaging the aerodigestive tract. In one animal, superficial bruising was observed in the ultrasound beam path. Otherwise, there were no adverse events. Analysis of the tissue histology found regions of damage consistent with acute thermal injury at the targeted locations. Conclusion: It is feasible to use a clinical MR-guided HIFU platform for extracorporeal ablation of porcine head and neck tissues. MR guidance and thermometry are sufficient to target and monitor treatment in the thyroid region, despite the presence of the inhomogeneous aerodigestive tract. Further study is necessary to assess efficacy and survival using a tumor model, and to examine what modifications should be made to the transducer positioning system and associated patient positioning aids to adapt it for clinical head and neck targets.Reference:[1] Esnault et al. (2011). Thyroid, 21(9), 965– 973. Funding support provided by Philips Healthcare. Ari Partanen is a paid employee of Philips Healthcare.« less

[Evaluation of the resolving power of different angles in MPR images of 16DAS-MDCT].

PubMed

Kimura, Mikio; Usui, Junshi; Nozawa, Takeo

2007-03-20

In this study, we evaluated the resolving power of three-dimensional (3D) multiplanar reformation (MPR) images with various angles by using 16 data acquisition system multi detector row computed tomography (16DAS-MDCT) . We reconstructed the MPR images using data with a 0.75 mm slice thickness of the axial image in this examination. To evaluate resolving power, we used an original new phantom (RC phantom) that can be positioned at any slice angle in MPR images. We measured the modulation transfer function (MTF) by using the methods of measuring pre-sampling MTF, and used Fourier transform of image data of the square wave chart. The scan condition and image reconstruction condition that were adopted in this study correspond to the condition that we use for three-dimensional computed tomographic angiography (3D-CTA) examination of the head in our hospital. The MTF of MPR images showed minimum values at slice angles in parallel with the axial slice, and showed maximum values at the sagittal slice and coronal slice angles that are parallel to the Z-axis. With an oblique MPR image, MTF did not change with angle changes in the oblique sagittal slice plane, but in the oblique coronal slice plane, MTF increased as the tilt angle increased from the axial plane to the Z plane. As a result, we could evaluate the resolving power of a head 3D image by measuring the MTF of the axial image and sagittal image or the coronal image.

Advanced Imaging in Osteoarthritis

PubMed Central

Li, Qi; Amano, Keiko; Link, Thomas M.; Ma, C. Benjamin

2016-01-01

Context: Radiography is widely accepted as the gold standard for diagnosing osteoarthritis (OA), but it has limitations when assessing early stage OA and monitoring progression. While there are improvements in the treatment of OA, the challenge is early recognition. Evidence Acquisition: MEDLINE and PubMed as well as professional orthopaedic and imaging websites were reviewed from 2006 to 2016. Study Design: Clinical review. Level of Evidence: Level 4. Results: Magnetic resonance imaging (MRI) can provide the most comprehensive assessment of joint injury and OA with the advantages of being noninvasive and multiplanar with excellent soft tissue contrast. However, MRI is expensive, time consuming, and not widely used for monitoring OA clinically. Computed tomography (CT) and CT arthrography (CTA) can also be used to evaluate OA, but these are also invasive and require radiation exposure. Ultrasound is particularly useful for evaluation of synovitis but not for progression of OA. Conclusion: MRI, CT, and CTA are available for the diagnosis and monitoring of OA. Improvement in techniques and decrease in cost can allow some of these modalities to be effective methods of detecting early OA. PMID:27510507

Three dimensional image correlation of CT, MR, and PET studies in radiotherapy treatment planning of brain tumors.

PubMed

Schad, L R; Boesecke, R; Schlegel, W; Hartmann, G H; Sturm, V; Strauss, L G; Lorenz, W J

1987-01-01

A treatment planning system for stereotactic convergent beam irradiation of deeply localized brain tumors is reported. The treatment technique consists of several moving field irradiations in noncoplanar planes at a linear accelerator facility. Using collimated narrow beams, a high concentration of dose within small volumes with a dose gradient of 10-15%/mm was obtained. The dose calculation was based on geometrical information of multiplanar CT or magnetic resonance (MR) imaging data. The patient's head was fixed in a stereotactic localization system, which is usable at CT, MR, and positron emission tomography (PET) installations. Special computer programs for correction of the geometrical MR distortions allowed a precise correlation of the different imaging modalities. The therapist can use combinations of CT, MR, and PET data for defining target volume. For instance, the superior soft tissue contrast of MR coupled with the metabolic features of PET may be a useful addition in the radiation treatment planning process. Furthermore, other features such as calculated dose distribution to critical structures can also be transferred from one set of imaging data to another and can be displayed as three-dimensional shaded structures.

Scalar localization of the electrode array after cochlear implantation: clinical experience using 64-slice multidetector computed tomography.

PubMed

Lane, John I; Witte, Robert J; Driscoll, Colin L W; Shallop, Jon K; Beatty, Charles W; Primak, Andrew N

2007-08-01

To use the improved resolution available with 64-slice multidetector computed tomography (MDCT) in vivo to localize the cochlear implant electrode array within the basal turn. Sixty-four-slice MDCT examinations of the temporal bones were retrospectively reviewed in 17 patients. Twenty-three implants were evaluated. Tertiary referral facility. All patients with previous cochlear implantation evaluated at our center between January 2004 and March 2006 were offered a computed tomographic examination as part of the study. In addition, preoperative computed tomographic examinations in patients being evaluated for a second bilateral device were included. Sixty-four-slice MDCT examination of the temporal bones. Localization of the electrode array within the basal turn from multiplanar reconstructions of the cochlea. Twenty-three implants were imaged in 17 patients. We were able to localize the electrode array within the scala tympani within the basal turn in 10 implants. In 3 implants, the electrode array was localized to the scala vestibuli. Migration of the electrode array from scala tympani to scala vestibuli was observed in three implants. Of the 7 implants in which localization of the electrode array was indeterminate, all had disease entities that obscured the definition of the normal cochlear anatomy. Sixty-four-slice MDCT with multiplanar reconstructions of the postoperative cochlea after cochlear implantation allows for accurate localization of the electrode array within the basal turn where normal cochlear anatomy is not obscured by the underlying disease process. Correlating the position of the electrode in the basal turn with surgical technique and implant design could be helpful in improving outcomes.

Imaging system for creating 3D block-face cryo-images of whole mice

NASA Astrophysics Data System (ADS)

Roy, Debashish; Breen, Michael; Salvado, Olivier; Heinzel, Meredith; McKinley, Eliot; Wilson, David

2006-03-01

We developed a cryomicrotome/imaging system that provides high resolution, high sensitivity block-face images of whole mice or excised organs, and applied it to a variety of biological applications. With this cryo-imaging system, we sectioned cryo-preserved tissues at 2-40 μm thickness and acquired high resolution brightfield and fluorescence images with microscopic in-plane resolution (as good as 1.2 μm). Brightfield images of normal and pathological anatomy show exquisite detail, especially in the abdominal cavity. Multi-planar reformatting and 3D renderings allow one to interrogate 3D structures. In this report, we present brightfield images of mouse anatomy, as well as 3D renderings of organs. For BPK mice model of polycystic kidney disease, we compared brightfield cryo-images and kidney volumes to MRI. The color images provided greater contrast and resolution of cysts as compared to in vivo MRI. We note that color cryo-images are closer to what a researcher sees in dissection, making it easier for them to interpret image data. The combination of field of view, depth of field, ultra high resolution and color/fluorescence contrast enables cryo-image volumes to provide details that cannot be found through in vivo imaging or other ex vivo optical imaging approaches. We believe that this novel imaging system will have applications that include identification of mouse phenotypes, characterization of diseases like blood vessel disease, kidney disease, and cancer, assessment of drug and gene therapy delivery and efficacy and validation of other imaging modalities.

Diagnostic concordance between mobile interfaces and conventional workstations for emergency imaging assessment.

PubMed

Venson, José Eduardo; Bevilacqua, Fernando; Berni, Jean; Onuki, Fabio; Maciel, Anderson

2018-05-01

Mobile devices and software are now available with sufficient computing power, speed and complexity to allow for real-time interpretation of radiology exams. In this paper, we perform a multivariable user study that investigates concordance of image-based diagnoses provided using mobile devices on the one hand and conventional workstations on the other hand. We performed a between-subjects task-analysis using CT, MRI and radiography datasets. Moreover, we investigated the adequacy of the screen size, image quality, usability and the availability of the tools necessary for the analysis. Radiologists, members of several teams, participated in the experiment under real work conditions. A total of 64 studies with 93 main diagnoses were analyzed. Our results showed that 56 cases were classified with complete concordance (87.69%), 5 cases with almost complete concordance (7.69%) and 1 case (1.56%) with partial concordance. Only 2 studies presented discordance between the reports (3.07%). The main reason to explain the cause of those disagreements was the lack of multiplanar reconstruction tool in the mobile viewer. Screen size and image quality had no direct impact on the mobile diagnosis process. We concluded that for images from emergency modalities, a mobile interface provides accurate interpretation and swift response, which could benefit patients' healthcare. Copyright © 2018 Elsevier B.V. All rights reserved.

3T MRI and 128-slice dual-source CT cisternography images of the cranial nerves a brief pictorial review for clinicians.

PubMed

Roldan-Valadez, Ernesto; Martinez-Anda, Jaime J; Corona-Cedillo, Roberto

2014-01-01

There is a broad community of health sciences professionals interested in the anatomy of the cranial nerves (CNs): specialists in neurology, neurosurgery, radiology, otolaryngology, ophthalmology, maxillofacial surgery, radiation oncology, and emergency medicine, as well as other related fields. Advances in neuroimaging using high-resolution images from computed tomography (CT) and magnetic resonance (MR) have made highly-detailed visualization of brain structures possible, allowing normal findings to be routinely assessed and nervous system pathology to be detected. In this article we present an integrated perspective of the normal anatomy of the CNs established by radiologists and neurosurgeons in order to provide a practical imaging review, which combines 128-slice dual-source multiplanar images from CT cisternography and 3T MR curved reconstructed images. The information about the CNs includes their origin, course (with emphasis on the cisternal segments and location of the orifices at the skull base transmitting them), function, and a brief listing of the most common pathologies affecting them. The scope of the article is clinical anatomy; readers will find specialized texts presenting detailed information about particular topics. Our aim in this article is to provide a helpful reference for understanding the complex anatomy of the cranial nerves. Copyright © 2013 Wiley Periodicals, Inc.

Computed Tomography of the Normal Bovine Tarsus.

PubMed

Hagag, U; Tawfiek, M; Brehm, W; Gerlach, K

2016-12-01

The objective of this study was to provide a detailed multiplanar computed tomographic (CT) anatomic reference for the bovine tarsus. The tarsal regions from twelve healthy adult cow cadavers were scanned in both soft and bone windows via a 16-slice multidetector CT scanner. Tarsi were frozen at -20 o C and sectioned to 10-mm-thick slices in transverse, dorsal and sagittal planes respecting the imaging protocol. The frozen sections were cleaned and then photographed. Anatomic structures were identified, labelled and compared with the corresponding CT images. The sagittal plane was indispensable for evaluation of bone contours, the dorsal plane was valuable in examination of the collateral ligaments, and both were beneficial for assessment of the tarsal joint articulations. CT images allowed excellent delineation between the cortex and medulla of bones, and the trabecular structure was clearly depicted. The tarsal soft tissues showed variable shades of grey, and the synovial fluid was the lowest attenuated structure. This study provided full assessment of the clinically relevant anatomic structures of the bovine tarsal joint. This technique may be of value when results from other diagnostic imaging techniques are indecisive. Images presented in this study should serve as a basic CT reference and assist in the interpretation of various bovine tarsal pathology. © 2016 Blackwell Verlag GmbH.

Accuracy and Specific Value of Cardiovascular 3D-Models in Pediatric CT-Angiography.

PubMed

Hammon, Matthias; Rompel, Oliver; Seuss, Hannes; Dittrich, Sven; Uder, Michael; Rüffer, Andrè; Cesnjevar, Robert; Ehret, Nicole; Glöckler, Martin

2017-12-01

Computed tomography (CT)-angiography is routinely performed prior to catheter-based and surgical treatment in congenital heart disease. To date, little is known about the accuracy and advantage of different 3D-reconstructions in CT-data. Exact anatomical information is crucial. We analyzed 35 consecutive CT-angiographies of infants with congenital heart disease. All datasets are reconstructed three-dimensionally using volume rendering technique (VRT) and threshold-based segmentation (stereolithographic model, STL). Additionally, the two-dimensional maximum intensity projection (MIP) reconstructs two-dimensional data. In each dataset and resulting image, measurements of vascular diameters for four different vessels were estimated and compared to the reference standard, measured via multiplanar reformation (MPR). The resulting measurements obtained via the STL-images, MIP-images, and the VRT-images were compared with the reference standard. There was a significant difference (p < 0.05) between measurements. The mean difference was 0.0 for STL-images, -0.1 for MIP-images, and -0.3 for VRT-images. The range of the differences was -0.7 to 1.0 mm for STL-images, -0.6 to 0.5 mm for MIP-images and -1.1 to 0.7 mm for VRT-images. There was an excellent correlation between the STL-, MIP-, VRT-measurements, and the reference standard. Inter-reader reliability was excellent (p < 0.01). STL-models of cardiovascular structures are more accurate than the traditional VRT-models. Additionally, they can be standardized and are reproducible.

Application of a novel metal artifact correction algorithm in flat-panel CT after coil embolization of brain aneurysms: intraindividual comparison.

PubMed

Buhk, J-H; Groth, M; Sehner, S; Fiehler, J; Schmidt, N O; Grzyska, U

2013-09-01

To evaluate a novel algorithm for correcting beam hardening artifacts caused by metal implants in computed tomography performed on a C-arm angiography system equipped with a flat panel (FP-CT). 16 datasets of cerebral FP-CT acquisitions after coil embolization of brain aneurysms in the context of acute subarachnoid hemorrhage have been reconstructed by applying a soft tissue kernel with and without a novel reconstruction filter for metal artifact correction. Image reading was performed in multiplanar reformations (MPR) in average mode on a dedicated radiological workplace in comparison to the preinterventional native multisection CT (MS-CT) scan serving as the anatomic gold standard. Two independent radiologists performed image scoring following a defined scale in direct comparison of the image data with and without artifact correction. For statistical analysis, a random intercept model was calculated. The inter-rater agreement was very high (ICC = 86.3 %). The soft tissue image quality and visualization of the CSF spaces at the level of the implants was substantially improved. The additional metal artifact correction algorithm did not induce impairment of the subjective image quality in any other brain regions. Adding metal artifact correction to FP-CT in an acute postinterventional setting helps to visualize the close vicinity of the aneurysm at a generally consistent image quality. © Georg Thieme Verlag KG Stuttgart · New York.

Hierarchical storage of large volume of multidector CT data using distributed servers

NASA Astrophysics Data System (ADS)

Ratib, Osman; Rosset, Antoine; Heuberger, Joris; Bandon, David

2006-03-01

Multidector scanners and hybrid multimodality scanners have the ability to generate large number of high-resolution images resulting in very large data sets. In most cases, these datasets are generated for the sole purpose of generating secondary processed images and 3D rendered images as well as oblique and curved multiplanar reformatted images. It is therefore not essential to archive the original images after they have been processed. We have developed an architecture of distributed archive servers for temporary storage of large image datasets for 3D rendering and image processing without the need for long term storage in PACS archive. With the relatively low cost of storage devices it is possible to configure these servers to hold several months or even years of data, long enough for allowing subsequent re-processing if required by specific clinical situations. We tested the latest generation of RAID servers provided by Apple computers with a capacity of 5 TBytes. We implemented a peer-to-peer data access software based on our Open-Source image management software called OsiriX, allowing remote workstations to directly access DICOM image files located on the server through a new technology called "bonjour". This architecture offers a seamless integration of multiple servers and workstations without the need for central database or complex workflow management tools. It allows efficient access to image data from multiple workstation for image analysis and visualization without the need for image data transfer. It provides a convenient alternative to centralized PACS architecture while avoiding complex and time-consuming data transfer and storage.

Effects of dose reduction on multi-detector computed tomographic images in evaluating the maxilla and mandible for pre-surgical implant planning: a cadaveric study.

PubMed

Koizumi, Hiroshi; Sur, Jaideep; Seki, Kenji; Nakajima, Koh; Sano, Tsukasa; Okano, Tomohiro

2010-08-01

To assess effects of dose reduction on image quality in evaluating maxilla and mandible for pre-surgical implant planning using cadavers. Six cadavers were used for the study using multi-detector computed tomography (CT) operated at 120 kV and the variable tube current of 80, 40, 20 and 10 mA. A slice thickness of 0.625 mm and pitch 1 were used. Multi-planar images perpendicular and parallel to dentitions were created. The images were evaluated by five oral radiologists in terms of visibility of the anatomical landmarks including alveolar crest, mandibular canal, floors of the maxillary sinus and nasal cavity, contours/cortical layer of jaw bones and the details of trabecular bone. Observers were asked to determine the quality of the images in comparison with 80 mA images based on the criteria: excellent, good, fair or non-diagnostic. The average scores of all observers were calculated for each specimen in all exposure conditions. The 40 mA images could visualize such landmarks and were evaluated to be same or almost equivalent in quality to the 80 mA images. Even the 20 mA images could be accepted just for diagnostic purpose for implant with substantial deterioration of the image quality. The 10 mA images may not be accepted because of the obscured contour caused by image noise. Significant dose reduction by lowering mA can be utilized for pre-surgical implant planning in multi-detector CT.

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT.

PubMed

Cho, S H; Sung, Y M; Kim, M S

2012-10-01

The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.

A survey of medical students on the impact of a new digital imaging library in the dissection room.

PubMed

Turmezei, T D; Tam, M D B S; Loughna, S

2009-09-01

Radiology has a recognised role in undergraduate anatomy education. The recent digitalisation of radiology has created new learning opportunities involving techniques such as image labelling, 3D reconstruction, and multiplanar reformatting. An opportunity was identified at the University of Nottingham to create a digital library of normal radiology images as a learner-driven adjunct in anatomy dissection sessions. We describe the process of creating a de novo digital library by sourcing images for presentation at computer workstations. Students' attitudes towards this new resource were assessed using a questionnaire which used a 5 point Likert scale and also offered free text responses. One hundred and forty-one out of 260 students (54%) completed the questionnaire. The most notable findings were: a positive response to the relevance of imaging to the session topics (median score 4), strong agreement that images should be available on the university website (median score 5), and disagreement that enough workstations were available (median score 2). About 24% of respondents suggested independently that images needed more labeling to help with orientation and identification. This first phase of supplying a comprehensive imaging library can be regarded as a success. Increasing availability and incorporating dynamic labeling are well recognized as important design concepts for electronic learning resources and these will be improved in the second phase of delivery as a direct result of student feedback. Hopefully other centers can benefit from this experience and will consider such a venture to be worthwhile.

Potential benefit of a simultaneous, side-by-side display of contrast MDCT and echocardiography over routine sequential imaging for assessment of adult congenital heart disease: A preliminary study.

PubMed

Oe, Hiroki; Watanabe, Nobuhisa; Miyoshi, Toru; Osawa, Kazuhiro; Akagi, Teiji; Kanazawa, Susumu; Ito, Hiroshi

2018-06-18

Management of adult congenital heart disease (ACHD) patients requires understanding of its complex morphology and functional features. An innovative imaging technique has been developed to display a virtual multi-planar reconstruction obtained from contrast-enhanced multidetector-computed tomography (MDCT) corresponding to the same cross-sectional image from transthoracic echocardiography (TTE). The aim of this study is to assess the usefulness of this imaging technology in ACHD patients. This study consisted of 46 consecutive patients (30 women; mean age, 52±18 years old) with ACHD who had undergone contrast MDCT. All patients underwent TTE within a week of MDCT. An experienced sonographer who did not know the results of MDCT conducted a diagnosis using TTE and, then, using the new imaging technology. We studied whether this imaging technology provided additional or unexpected findings or makes more accurate diagnosis. In this imaging technology, MDCT cross-section provides higher-resolution image to the deep compared to corresponding TTE image. Depending on the MDCT section which can be arbitrarily set under the echo guide, we can diagnose unexpected or incremental lesions or more accurately assess the severity of the lesion in 27 patients (59%) compared to TTE study alone. This imaging technology was useful in the following situations: CONCLUSIONS: This integrated imaging technology provides incremental role over TTE in complex anatomy, and allows functional information in ACHD patients. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

"Buckle" rib fracture: an artifact following cardio-pulmonary resuscitation detected on postmortem CT.

PubMed

Yang, Kyung-Moo; Lynch, Matthew; O'Donnell, Chris

2011-09-01

Buckle rib fractures are incomplete fractures involving the inner cortex alone, and are rarely detected on routine chest X-ray or at autopsy. The characteristics of these fractures have not been well evaluated in situ although they are commonly observed on postmortem CT images especially following CPR. The postmortem CT findings in 42 cases showing buckle rib fractures caused by CPR were reviewed. The cause of death in all cases was non-traumatic. The shape, number, location, and distribution of these buckle rib fractures and their relationship to other types of rib fractures were evaluated using a novel oblique axial multiplanar reconstruction technique. Almost all incomplete rib fractures associated with CPR are buckle rib fractures (90.5%). All rib fractures were distributed from the second to ninth ribs with over 95% being within the second to seventh ribs. Buckle rib fractures are dominant in the seventh to ninth ribs and the proportion of buckle rib fractures located in the vicinity of the costochondral junctions increases with the lower ribs. Over 97% of all CPR associated rib fractures are located in the anterior one third of the ribs based on a new measurement method utilizing oblique axial multiplanar reconstruction of the CT data. When recognition of incomplete or buckle rib fractures on postmortem CT is taken into account, detection of symmetry and continuity of rib fractures typically associated with CPR is improved compared with the detection of complete fractures alone. Recognition of buckle rib fractures and their characteristics on postmortem CT is of benefit to the forensic pathologist in evaluating the possibility of CPR and the differentiation of resuscitative artifact from forensically significant visceral injury observed at autopsy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

[Evaluation of upper cervical spine injury (C1-C2) with computed tomography].

PubMed

Siemianowicz, Anna; Baron, Jan; Wawrzynek, Wojciech; Koczy, Bogdan; Kasprowska, Sabina

2006-01-01

Cervical spine injuries are common and essential diagnostic problem. Diagnostic imaging is necessary for proper and effective treatment. Helical computed tomography (CT) and plain radiography are the basic diagnostic methods in cervical spine injuries. The purpose of this work was the comparison of CT examination of the upper cervical spine (CI-C2) with patients' clinical state. Twenty four patients (17 men and 7 women) were introduced into the study. The most common cause of cervical spine injuries were car accidents (48.5%). CT examination was performed in all patients. Six patients (25%) had multilevel injury, localized at C1-C2 level and in the lower part of cervical spine. The main pathology diagnosed by CT in the studied group was rotatory subluxation (66.6%). Eight patients (33.3%), with rotatory subluxation did not present any abnormalities in neurological examination performed immediately after the admission to the hospital. C1 and/or C2 fractures were diagnosed in 11 patients (45.8%), in some cases (in 3 patients - 12.5%) they were accompanied by rotatory subluxations. CT examination is the basic technique of diagnostic imaging in a case of cervical spine injuries. It enables quick, accurate and precise evaluation of bone structures and surrounding soft tissues. CT also enables multiplanar imaging and 3-dimentional imaging.

[Preoperative assessment of renal vascular anatomy for donor nephrectomy: Is CT superior to MRI?].

PubMed

Arvin-Berod, A; Bricault, I; Terrier, N; Skowron, O; Cadi, P; Boillot, B; Thuillier, C; Cluze, C; Descotes, J-L; Rambeaud, J-J; Long, J-A

2011-01-01

computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are both used in the preoperative assessment of vascular anatomy before donor nephrectomy. Our objective was to determine retrospectively and to compare the sensitivity of CTA and MRA imaging in preoperative renal vascularisation in living kidney donors. between 1999 and 2007, 42 kidney donors were assessed in our center: 27 by MRA, 10 by CTA, and five by both techniques. Images were interpreted using multiplanar reconstructions. Results were compared retrospectively with peroperative findings; discordant cases were re-examined by an experienced radiologist. Numbers of vessels detected with imaging methods was compared with numbers actually found at the operating time. MRA showed 35/43 arteries (Se 81.4 %) and 33/34 veins (Se 97.1 %), and CTA showed 18/18 arteries (Se 100 %) and 15/16 veins (Se 93.8 %). The presence of multiple arteries was detected in only one third of cases (3/9) on MRI scans; this difference was statistically significant. The missed arteries were not detected on second examination of the MRI scans with the knowledge of peroperative findings. MRA is less sensitive than CTA for preoperative vascularisation imaging in living renal donors, especially in the detection of multiple renal arteries. 2010 Elsevier Masson SAS. All rights reserved.

Multislice CT Angiography in Renal Artery Stent Evaluation: Prospective Comparison with Intra-Arterial Digital Subtraction Angiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raza, Syed A.; Chughtai, Aamer R.; Wahba, Mona

2004-01-15

Purpose: To assess the role of multislice computed tomography angiography (MCTA) in the evaluation of renal artery stents, using intra-arterial digital subtraction angiography (DSA) as the gold standard. Methods: Twenty consecutive patients (15 men, 5 women) with 23 renal artery stents prospectively underwent both MCTA and DSA. Axial images, multiplanar reconstructions and maximum intensity projection images were used for diagnosis. The MCTA and DSA images were each interpreted without reference to the result of the other investigation. Results:The three cases of restenosis on DSA were detected correctly by MCTA; in 19 cases where MCTA showed a fully patent stent, themore » DSA was also negative. Sensitivity and negative predictive value (NPV) of MCTA were therefore 100%. In four cases, MCTA showed apparently minimal disease which was not shown on DSA. These cases are taken as false positive giving a specificity of 80% and a positive predictive value of 43%. Conclusion: The high sensitivity and NPV suggest MCTA may be useful as a noninvasive screen for renal artery stentrestenosis. MCTA detected mild disease in a few patients which was not confirmed on angiography.« less

Three surgical planes identified in laparoscopic complete mesocolic excision for right-sided colon cancer.

PubMed

Zhu, Da-Jian; Chen, Xiao-Wu; OuYang, Man-Zhao; Lu, Yan

2016-01-12

Complete mesocolic excision provides a correct anatomical plane for colon cancer surgery. However, manifestation of the surgical plane during laparoscopic complete mesocolic excision versus in computed tomography images remains to be examined. Patients who underwent laparoscopic complete mesocolic excision for right-sided colon cancer underwent an abdominal computed tomography scan. The spatial relationship of the intraoperative surgical planes were examined, and then computed tomography reconstruction methods were applied. The resulting images were analyzed. In 44 right-sided colon cancer patients, the surgical plane for laparoscopic complete mesocolic excision was found to be composed of three surgical planes that were identified by computed tomography imaging with cross-sectional multiplanar reconstruction, maximum intensity projection, and volume reconstruction. For the operations performed, the mean bleeding volume was 73±32.3 ml and the mean number of harvested lymph nodes was 22±9.7. The follow-up period ranged from 6-40 months (mean 21.2), and only two patients had distant metastases. The laparoscopic complete mesocolic excision surgical plane for right-sided colon cancer is composed of three surgical planes. When these surgical planes were identified, laparoscopic complete mesocolic excision was a safe and effective procedure for the resection of colon cancer.

Eleven fetal echocardiographic planes using 4-dimensional ultrasound with spatio-temporal image correlation (STIC): a logical approach to fetal heart volume analysis.

PubMed

Jantarasaengaram, Surasak; Vairojanavong, Kittipong

2010-09-15

Theoretically, a cross-sectional image of any cardiac planes can be obtained from a STIC fetal heart volume dataset. We described a method to display 11 fetal echocardiographic planes from STIC volumes. Fetal heart volume datasets were acquired by transverse acquisition from 200 normal fetuses at 15 to 40 weeks of gestation. Analysis of the volume datasets using the described technique to display 11 echocardiographic planes in the multiplanar display mode were performed offline. Volume datasets from 18 fetuses were excluded due to poor image resolution. The mean visualization rates for all echocardiographic planes at 15-17, 18-22, 23-27, 28-32 and 33-40 weeks of gestation fetuses were 85.6% (range 45.2-96.8%, N = 31), 92.9% (range 64.0-100%, N = 64), 93.4% (range 51.4-100%, N = 37), 88.7%(range 54.5-100%, N = 33) and 81.8% (range 23.5-100%, N = 17) respectively. Overall, the applied technique can favorably display the pertinent echocardiographic planes. Description of the presented method provides a logical approach to explore the fetal heart volumes.

Dynamic Neuromuscular Control of the Lower Limbs in Response to Unexpected Single-Planar versus Multi-Planar Support Perturbations in Young, Active Adults.

PubMed

Malfait, Bart; Staes, Filip; de Vries, Aijse; Smeets, Annemie; Hawken, Malcolm; Robinson, Mark A; Vanrenterghem, Jos; Verschueren, Sabine

2015-01-01

An anterior cruciate ligament (ACL) injury involves a multi-planar injury mechanism. Nevertheless, unexpected multi-planar perturbations have not been used to screen athletes in the context of ACL injury prevention yet could reveal those more at risk. The objective of this study was to compare neuromuscular responses to multi-planar (MPP) and single-planar perturbations (SPP) during a stepping-down task. These results might serve as a basis for future implementation of external perturbations in ACL injury screening programs. Thirteen young adults performed a single leg stepping-down task in eight conditions (four MPP and four SPP with a specified amplitude and velocity). The amplitudes of vastus lateralis (VL), vastus medialis (VM), hamstrings lateralis (HL), hamstrings medialis (HM) EMG activity, medio-lateral and anterior-posterior centre of mass (COM) displacements, the peak knee flexion and abduction angles were compared between conditions using an one-way ANOVA. Number of stepping responses were monitored during all conditions. Significantly greater muscle activity levels were found in response to the more challenging MPP and SPP compared to the less challenging conditions (p < 0.05). No differences in neuromuscular activity were found between the MPP conditions and their equivalents in the SPP. Eighteen stepping responses were monitored in the SPP versus nine in the MPP indicating that the overall neuromuscular control was even more challenged during the SPP which was supported by greater COM displacements in the SPP. The more intense MPP and SPP evoked different neuromuscular responses resulting in greater muscle activity levels compared to small perturbations. Based on the results of COM displacements and based on the amount of stepping responses, dynamic neuromuscular control of the knee joint appeared less challenged during the MPP. Therefore, future work should investigate extensively if other neuromuscular differences (i.e. co-activation patterns and kinetics) exist between MPP and SPP. In addition, future work should examine the influence on the neuromuscular control of the magnitude of the perturbations and the magnitude of stepping height and stepping distance.

Operative treatment of 2-part surgical neck fractures of the proximal humerus (AO 11-A3) in the elderly: Cement augmented locking plate Philos™ vs. proximal humerus nail MultiLoc®.

PubMed

Helfen, Tobias; Siebenbürger, Georg; Mayer, Marcel; Böcker, Wolfgang; Ockert, Ben; Haasters, Florian

2016-10-28

Proximal humeral fractures are with an incidence of 4-5 % the third most common fractures in the elderly. In 20 % of humeral fractures there is an indication for surgical treatment according to the modified Neer-Criteria. A secondary varus dislocation of the head fragment and cutting-out are the most common complications of angle stable locking plates in AO11-A3 fractures of the elderly. One possibility to increase the stability of the screw-bone-interface is the cement augmentation of the screw tips. A second is the use of a multiplanar angle stablentramedullary nail that might provide better biomechanical properties after fixation of 2-part-fractures. A comparison of these two treatment options augmented locking plate versus multiplanar angle stable locking nail in 2-part surgical neck fractures of the proximal humerus has not been carried out up to now. Forty patients (female/male, ≥60 years or female postmenopausal) with a 2-part-fracture of the proximal humerus (AO type 11-A3) will be randomized to either to augmented plate fixation group (PhilosAugment) or to multiplanar intramedullary nail group (MultiLoc). Outcome parameters are Disabilities of the Shoulder, Arm and Hand-Score (DASH) Constant Score (CS), American Shoulder and Elbow Score (ASES), Oxford Shoulder Score (OSS), Range of motion (ROM) and Short Form 36 (SF-36) after 3 weeks, 6 weeks, 3 months, 6 months, 12 and 24 months. Because of the lack of clinical studies that compare cement augmented locking plates with multiplanar humeral nail systems after 2-part surgical neck fractures of the proximal humerus, the decision of surgical method currently depends only on surgeons preference. Because only a randomized clinical trial (RCT) can sufficiently answer the question if one treatment option provides advantages compared to the other method we are planning to perform a RCT. Clinical Trial ( NCT02609906 ), November 18, 2015, registered retrospectively.

Feasibility of imaging superficial palmar arch using micro-ultrasound, 7T and 3T magnetic resonance imaging.

PubMed

Pruzan, Alison N; Kaufman, Audrey E; Calcagno, Claudia; Zhou, Yu; Fayad, Zahi A; Mani, Venkatesh

2017-02-28

To demonstrate feasibility of vessel wall imaging of the superficial palmar arch using high frequency micro-ultrasound, 7T and 3T magnetic resonance imaging (MRI). Four subjects (ages 22-50 years) were scanned on a micro-ultrasound system with a 45-MHz transducer (Vevo 2100, VisualSonics). Subjects' hands were then imaged on a 3T clinical MR scanner (Siemens Biograph MMR) using an 8-channel special purpose phased array carotid coil. Lastly, subjects' hands were imaged on a 7T clinical MR scanner (Siemens Magnetom 7T Whole Body Scanner) using a custom built 8-channel transmit receive carotid coil. All three imaging modalities were subjectively analyzed for image quality and visualization of the vessel wall. Results of this very preliminary study indicated that vessel wall imaging of the superficial palmar arch was feasible with a whole body 7T and 3T MRI in comparison with micro-ultrasound. Subjective analysis of image quality (1-5 scale, 1: poorest, 5: best) from B mode, ultrasound, 3T SPACE MRI and 7T SPACE MRI indicated that the image quality obtained at 7T was superior to both 3T MRI and micro-ultrasound. The 3D SPACE sequence at both 7T and 3T MRI with isotropic voxels allowed for multi-planar reformatting of images and allowed for less operator dependent results as compared to high frequency micro-ultrasound imaging. Although quantitative analysis revealed that there was no significant difference between the three methods, the 7T Tesla trended to have better visibility of the vessel and its wall. Imaging of smaller arteries at the 7T is feasible for evaluating atherosclerosis burden and may be of clinical relevance in multiple diseases.

A web-based instruction module for interpretation of craniofacial cone beam CT anatomy.

PubMed

Hassan, B A; Jacobs, R; Scarfe, W C; Al-Rawi, W T

2007-09-01

To develop a web-based module for learner instruction in the interpretation and recognition of osseous anatomy on craniofacial cone-beam CT (CBCT) images. Volumetric datasets from three CBCT systems were acquired (i-CAT, NewTom 3G and AccuiTomo FPD) for various subjects using equipment-specific scanning protocols. The datasets were processed using multiple software to provide two-dimensional (2D) multiplanar reformatted (MPR) images (e.g. sagittal, coronal and axial) and three-dimensional (3D) visual representations (e.g. maximum intensity projection, minimum intensity projection, ray sum, surface and volume rendering). Distinct didactic modules which illustrate the principles of CBCT systems, guided navigation of the volumetric dataset, and anatomic correlation of 3D models and 2D MPR graphics were developed using a hybrid combination of web authoring and image analysis techniques. Interactive web multimedia instruction was facilitated by the use of dynamic highlighting and labelling, and rendered video illustrations, supplemented with didactic textual material. HTML coding and Java scripting were heavily implemented for the blending of the educational modules. An interactive, multimedia educational tool for visualizing the morphology and interrelationships of osseous craniofacial anatomy, as depicted on CBCT MPR and 3D images, was designed and implemented. The present design of a web-based instruction module may assist radiologists and clinicians in learning how to recognize and interpret the craniofacial anatomy of CBCT based images more efficiently.

Time-Resolved 3D Quantitative Flow MRI of the Major Intracranial Vessels: Initial Experience and Comparative Evaluation at 1.5T and 3.0T in Combination With Parallel Imaging

PubMed Central

Bammer, Roland; Hope, Thomas A.; Aksoy, Murat; Alley, Marcus T.

2012-01-01

Exact knowledge of blood flow characteristics in the major cerebral vessels is of great relevance for diagnosing cerebrovascular abnormalities. This involves the assessment of hemodynamically critical areas as well as the derivation of biomechanical parameters such as wall shear stress and pressure gradients. A time-resolved, 3D phase-contrast (PC) MRI method using parallel imaging was implemented to measure blood flow in three dimensions at multiple instances over the cardiac cycle. The 4D velocity data obtained from 14 healthy volunteers were used to investigate dynamic blood flow with the use of multiplanar reformatting, 3D streamlines, and 4D particle tracing. In addition, the effects of magnetic field strength, parallel imaging, and temporal resolution on the data were investigated in a comparative evaluation at 1.5T and 3T using three different parallel imaging reduction factors and three different temporal resolutions in eight of the 14 subjects. Studies were consistently performed faster at 3T than at 1.5T because of better parallel imaging performance. A high temporal resolution (65 ms) was required to follow dynamic processes in the intracranial vessels. The 4D flow measurements provided a high degree of vascular conspicuity. Time-resolved streamline analysis provided features that have not been reported previously for the intracranial vasculature. PMID:17195166

Inter- and intra-observer variability of radiography and computed tomography for evaluation of Zurich cementless acetabular cup placement ex vivo.

PubMed

Leasure, Jessica O; Peck, Jeffrey N; Villamil, Armando; Fiore, Kara L; Tano, Cheryl A

2016-11-23

To evaluate the inter- and intra-observer variability in measurement of the angle of lateral opening (ALO) and version angle measurement using digital radiography and computed tomography (CT). Each hemipelvis was implanted with a cementless acetabular cup. Ventrodorsal and mediolateral radiographs were made of each pelvis, followed by CT imaging. After removal of the first cup, the pelves were implanted with an acetabular cup in the contralateral acetabulum and imaging was repeated. Three surgeons measured the ALO and version angles three times for each cup from the mediolateral radiographic projection. The same measurements were made using three-dimensional multiplanar reconstructions from CT images. Two anatomical axes were used to measure pelvic inclination in the sagittal plane, resulting in six measurements per cup. Two-way repeated measures analysis of variance evaluated inter- and intra-observer repeatability for radiographic and CT-based measurements. Version angle based on radiographic measurement did not differ within surgeons (p = 0.433), but differed between surgeons (p <0.001). Radiographic measurement of ALO differed within surgeons (p = 0.006) but not between surgeons (p = 0.989). The ALO and version angle measured on CT images did not differ with or between surgeons. Assessment of inter- and intra-observer measurement of ALO and version angle was more reproducible using CT images than conventional mediolateral radiography for a Zurich cementless acetabular cup.

Endovascular abdominal aortic aneurysm sizing and case planning using the TeraRecon Aquarius workstation.

PubMed

Lee, W Anthony

2007-01-01

The gold standard for preoperative evaluation of an aortic aneurysm is a computed tomography angiogram (CTA). Three-dimensional reconstruction and analysis of the computed tomography data set is enormously helpful, and even sometimes essential, in proper sizing and planning for endovascular stent graft repair. To a large extent, it has obviated the need for conventional angiography for morphologic evaluation. The TeraRecon Aquarius workstation (San Mateo, Calif) represents a highly sophisticated but user-friendly platform utilizing a combination of task-specific hardware and software specifically designed to rapidly manipulate large Digital Imaging and Communications in Medicine (DICOM) data sets and provide surface-shaded and multiplanar renderings in real-time. This article discusses the basics of sizing and planning for endovascular abdominal aortic aneurysm repair and the role of 3-dimensional analysis using the TeraRecon workstation.

[Usefulness of curved coronal MPR imaging for the diagnosis of cervical radiculopathy].

PubMed

Inukai, Chikage; Inukai, Takashi; Matsuo, Naoki; Shimizu, Ikuo; Goto, Hisaharu; Takagi, Teruhide; Takayasu, Masakazu

2010-03-01

In surgical treatment of cervical radiculopathy, localization of the responsible lesions by various imaging modalities is essential. Among them, MRI is non-invasive and plays a primary role in the assessment of spinal radicular symptoms. However, demonstration of nerve root compression is sometimes difficult by the conventional methods of MRI, such as T1 weighted (T1W) and T2 weighted (T2W) sagittal or axial images. We have applied a new technique of curved coronal multiplanar reconstruction (MPR) imaging for the diagnosis of cervical radiculopathy. Ten patients (4 male, 6 female) with ages between 31 and 79 year-old, who had clinical diagnosis of cervical radiculopathy, were included in this study. Seven patients underwent anterior key-hole foraminotomy to decompress the nerve root with successful results. All the patients had 3D MRI studies, such as true fast imaging with steady-state precession (FISP), 3DT2W sampling perfection with application optimized contrasts using different fillip angle evolution (SPACE), and 3D multi-echo data image combination (MEDIC) imagings in addition to the routine MRI (1.5 T Avanto, Siemens, Germany) with a phased array coil. The curved coronal MPR images were produced from these MRI data using a workstation. The nerve root compression was diagnosed by curved coronal MPR images in all the patients. The compression sites were compatible with those of the operative findings in 7 patients, who underwent surgical treatment. The MEDIC imagings were the most demonstrable to visualize the nerve root, while the 3D-space imagings were the next. The curved coronal MPR imaging is useful for the diagnosis of accurate localization of the compressing lesions in patients with cervical radiculopathy.

Computed tomographic anatomy of the nasal cavity, paranasal sinuses and tympanic cavity of the koala.

PubMed

Hemsley, S; Palmer, H; Canfield, R B; Stewart, M E B; Krockenberger, M B; Malik, R

2013-09-01

To use cross-sectional imaging (helical computed tomography (CT)) combined with conventional anatomical dissection to define the normal anatomy of the nasal cavity and bony cavitations of the koala skull. Helical CT scans of the heads of nine adult animals were obtained using a multislice scanner acquiring thin slices reconstructed in the transverse, sagittal and dorsal planes. Subsequent anatomical dissection permitted confirmation of correct identification and further delineation of bony and air-filled structures visible in axial and multiplanar reformatted CT images. The nasal cavity was relatively simple, with little scrolling of nasal conchae, but bony cavitations were complex and extensive. A rostral maxillary recess and ventral conchal, caudal maxillary, frontal and sphenoidal paranasal sinuses were identified and characterised. Extensive temporal bone cavitation was shown to be related to a large epitympanic recess. The detailed anatomical data provided are applicable to future functional and comparative anatomical studies, as well as providing a preliminary atlas for clinical investigation of conditions such as cryptococcal rhinosinusitis, a condition more common in the koala than in many other species. © 2013 Australian Veterinary Association.

[Differential diagnosis of Dandy-Walker syndrome different presentations].

PubMed

Tobías-González, Pablo; Gil Mira, Mar; Valero de Bernabé, Javier; Zapardiel, Ignacio

2012-08-01

Dandy-Walker syndrome is a set of abnormalities of the posterior fossa including three modalities: classic Dandy-Walker malformation, Dandy-Walker variant and mega-cisterna magna. Our objective is clarify the differential diagnosis among these entities. Descriptive and retrospective study of Dandy-Walker cases diagnosed at our Department during the last five years plus a review of the related Medical literature. Three cases of Dandy-Walker modalities are reported: one case of classic Dandy-Walker malformation, one case of Dandy-Walker variant, and one case of false Dandy-Walker. In the first two cases the patients underwent legal abortion, whereas in the last one a healthy male newborn was delivered in the week 38 of gestation. Malformations in the posterior fossa, including Dandy-Walker syndrome, are still a challenge in prenatal diagnosis. Technical developments in imaging, such as in three-dimensional sonography and magnetic resonance, allow higher resolution and multiplanar images for an easier diagnose. There is a high rate of false positive, particularly before the 18th week of gestation. It is advisable not to establish a final diagnose before that week.

The Application of Surgical Navigation in the Treatment of Temporomandibular Joint Ankylosis.

PubMed

Sun, Guowen; Lu, Mingxing; Hu, Qingang

2015-11-01

The purpose of this study was to assess the safety and the accuracy of surgical navigation technology in the resection of severe ankylosis of the mandibular condyle with the middle cranial fossa. The computed tomography scan data were transferred to a Windows-based computer workstation, and the patient's individual anatomy was assessed in multiplanar views at the workstation. In the operation, the patient and the virtual image were matched by individual registration with the reference points which were set on the skull bone surface and the teeth. Then, the real-time navigation can be performed. The acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the operative result in 2 cases. Both of the operations were performed successfully with the guidance of real-time navigation. The application of surgical navigation has enhanced the safety and the accuracy of the surgery for bony ankylosis of temporomandibular joint. The use of surgical navigation resulted in the promotion of accurate and safe surgical excision of the ankylosed skull base tissue.

Pitfalls in 16-detector row CT of the coronary arteries.

PubMed

Nakanishi, Tadashi; Kayashima, Yasuyo; Inoue, Rintaro; Sumii, Kotaro; Gomyo, Yukihiko

2005-01-01

Recently developed 16-detector row computed tomography (CT) has been introduced as a reliable noninvasive imaging modality for evaluating the coronary arteries. In most cases, with appropriate premedication that includes beta-blockers and nitroglycerin, ideal data sets can be acquired from which to obtain excellent-quality coronary CT angiograms, most often with multiplanar reformation, thin-slab maximum intensity projection, and volume rendering. However, various artifacts associated with data creation and reformation, postprocessing methods, and image interpretation can hamper accurate diagnosis. These artifacts can be related to pulsation (nonassessable segments, pseudostenosis) as well as rhythm disorders, respiratory issues, partial volume averaging effect, high-attenuation entities, inappropriate scan pitch, contrast material enhancement, and patient body habitus. Some artifacts have already been resolved with technical advances, whereas others represent partially inherent limitations of coronary CT angiography. Familiarity with the pitfalls of coronary angiography with 16-detector row CT, coupled with the knowledge of both the normal anatomy and anatomic variants of the coronary arteries, can almost always help radiologists avoid interpretive errors in the diagnosis of coronary artery stenosis. (c) RSNA, 2005.

A combined solenoid-surface RF coil for high-resolution whole-brain rat imaging on a 3.0 Tesla clinical MR scanner.

PubMed

Underhill, Hunter R; Yuan, Chun; Hayes, Cecil E

2010-09-01

Rat brain models effectively simulate a multitude of human neurological disorders. Improvements in coil design have facilitated the wider utilization of rat brain models by enabling the utilization of clinical MR scanners for image acquisition. In this study, a novel coil design, subsequently referred to as the rat brain coil, is described that exploits and combines the strengths of both solenoids and surface coils into a simple, multichannel, receive-only coil dedicated to whole-brain rat imaging on a 3.0 T clinical MR scanner. Compared with a multiturn solenoid mouse body coil, a 3-cm surface coil, a modified Helmholtz coil, and a phased-array surface coil, the rat brain coil improved signal-to-noise ratio by approximately 72, 61, 78, and 242%, respectively. Effects of the rat brain coil on amplitudes of static field and radiofrequency field uniformity were similar to each of the other coils. In vivo, whole-brain images of an adult male rat were acquired with a T(2)-weighted spin-echo sequence using an isotropic acquisition resolution of 0.25 x 0.25 x 0.25 mm(3) in 60.6 min. Multiplanar images of the in vivo rat brain with identification of anatomic structures are presented. Improvement in signal-to-noise ratio afforded by the rat brain coil may broaden experiments that utilize clinical MR scanners for in vivo image acquisition. 2010 Wiley-Liss, Inc.

Echocardiographic anatomy of the mitral valve: a critical appraisal of 2-dimensional imaging protocols with a 3-dimensional perspective.

PubMed

Mahmood, Feroze; Hess, Philip E; Matyal, Robina; Mackensen, G Burkhard; Wang, Angela; Qazi, Aisha; Panzica, Peter J; Lerner, Adam B; Maslow, Andrew

2012-10-01

To highlight the limitations of traditional 2-dimensional (2D) echocardiographic mitral valve (MV) examination methodologies, which do not account for patient-specific transesophageal echocardiographic (TEE) probe adjustments made during an actual clinical perioperative TEE examination. Institutional quality-improvement project. Tertiary care hospital. Attending anesthesiologists certified by the National Board of Echocardiography. Using the technique of multiplanar reformatting with 3-dimensional (3D) data, ambiguous 2D images of the MV were generated, which resembled standard midesophageal 2D views. Based on the 3D image, the MV scallops visualized in each 2D image were recognized exactly by the position of the scan plane. Twenty-three such 2D MV images were created in a presentation from the 3D datasets. Anesthesia staff members (n = 13) were invited to view the presentation based on the 2D images only and asked to identify the MV scallops. Their responses were scored as correct or incorrect based on the 3D image. The overall accuracy was 30.4% in identifying the MV scallops. The transcommissural view was identified correctly >90% of the time. The accuracy of the identification of A1, A3, P1, and P3 scallops was <50%. The accuracy of the identification of A2P2 scallops was ≥50%. In the absence of information on TEE probe adjustments performed to acquire a specific MV image, it is possible to misidentify the scallops. Copyright © 2012 Elsevier Inc. All rights reserved.

Super-resolution reconstruction for 4D computed tomography of the lung via the projections onto convex sets approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yu, E-mail: yuzhang@smu.edu.cn, E-mail: qianjinfeng08@gmail.com; Wu, Xiuxiu; Yang, Wei

2014-11-01

Purpose: The use of 4D computed tomography (4D-CT) of the lung is important in lung cancer radiotherapy for tumor localization and treatment planning. Sometimes, dense sampling is not acquired along the superior–inferior direction. This disadvantage results in an interslice thickness that is much greater than in-plane voxel resolutions. Isotropic resolution is necessary for multiplanar display, but the commonly used interpolation operation blurs images. This paper presents a super-resolution (SR) reconstruction method to enhance 4D-CT resolution. Methods: The authors assume that the low-resolution images of different phases at the same position can be regarded as input “frames” to reconstruct high-resolution images.more » The SR technique is used to recover high-resolution images. Specifically, the Demons deformable registration algorithm is used to estimate the motion field between different “frames.” Then, the projection onto convex sets approach is implemented to reconstruct high-resolution lung images. Results: The performance of the SR algorithm is evaluated using both simulated and real datasets. Their method can generate clearer lung images and enhance image structure compared with cubic spline interpolation and back projection (BP) method. Quantitative analysis shows that the proposed algorithm decreases the root mean square error by 40.8% relative to cubic spline interpolation and 10.2% versus BP. Conclusions: A new algorithm has been developed to improve the resolution of 4D-CT. The algorithm outperforms the cubic spline interpolation and BP approaches by producing images with markedly improved structural clarity and greatly reduced artifacts.« less

Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT

PubMed Central

Cho, S H; Sung, Y M; Kim, M S

2012-01-01

Objective The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. Methods 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. Results 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Conclusion Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images. PMID:22514102

Intratympanic Iodine Contrast Injection Diffuses Across the Round Window Membrane Allowing for Perilymphatic CT Volume Acquisition Imaging.

PubMed

Abt, Nicholas B; Lehar, Mohamed; Guajardo, Carolina Trevino; Penninger, Richard T; Ward, Bryan K; Pearl, Monica S; Carey, John P

2016-04-01

Whether the round window membrane (RWM) is permeable to iodine-based contrast agents (IBCA) is unknown; therefore, our goal was to determine if IBCAs could diffuse through the RWM using CT volume acquisition imaging. Imaging of hydrops in the living human ear has attracted recent interest. Intratympanic (IT) injection has shown gadolinium's ability to diffuse through the RWM, enhancing the perilymphatic space. Four unfixed human cadaver temporal bones underwent intratympanic IBCA injection using three sequentially studied methods. The first method was direct IT injection. The second method used direct RWM visualization via tympanomeatal flap for IBCA-soaked absorbable gelatin pledget placement. In the third method, the middle ear was filled with contrast after flap elevation. Volume acquisition CT images were obtained immediately postexposure, and at 1-, 6-, and 24-hour intervals. Postprocessing was accomplished using color ramping and subtraction imaging. After the third method, positive RWM and perilymphatic enhancement were observed with endolymph sparing. Gray scale and color ramp multiplanar reconstructions displayed increased signal within the cochlea compared with precontrast imaging. The cochlea was measured for attenuation differences compared with pure water, revealing a preinjection average of -1,103 HU and a postinjection average of 338 HU. Subtraction imaging shows enhancement remaining within the cochlear space, Eustachian tube, middle ear epithelial lining, and mastoid. Iohexol iodine contrast is able to diffuse across the RWM. Volume acquisition CT imaging was able to detect perilymphatic enhancement at 0.5-mm slice thickness. The clinical application of IBCA IT injection seems promising but requires further safety studies.

Diffusion weighted whole body imaging with background body signal suppression (DWIBS): technical improvement using free breathing, STIR and high resolution 3D display.

PubMed

Takahara, Taro; Imai, Yutaka; Yamashita, Tomohiro; Yasuda, Seiei; Nasu, Seiji; Van Cauteren, Marc

2004-01-01

To examine a new way of body diffusion weighted imaging (DWI) using the short TI inversion recovery-echo planar imaging (STIR-EPI) sequence and free breathing scanning (diffusion weighted whole body imaging with background body signal suppression; DWIBS) to obtain three-dimensional displays. 1) Apparent contrast-to-noise ratios (AppCNR) between lymph nodes and surrounding fat tissue were compared in three types of DWI with and without breath-holding, with variable lengths of scan time and slice thickness. 2) The STIR-EPI sequence and spin echo-echo planar imaging (SE-EPI) sequence with chemical shift selective (CHESS) pulse were compared in terms of their degree of fat suppression. 3) Eleven patients with neck, chest, and abdominal malignancy were scanned with DWIBS for evaluation of feasibility. Whole body imaging was done in a later stage of the study using the peripheral vascular coil. The AppCNR of 8 mm slice thickness images reconstructed from 4 mm slice thickness source images obtained in a free breathing scan of 430 sec were much better than 9 mm slice thickness breath-hold scans obtained in 25 sec. High resolution multi-planar reformat (MPR) and maximum intensity projection (MIP) images could be made from the data set of 4 mm slice thickness images. Fat suppression was much better in the STIR-EPI sequence than SE-EPI with CHESS pulse. The feasibility of DWIBS was showed in clinical scans of 11 patients. Whole body images were successfully obtained with adequate fat suppression. Three-dimensional DWIBS can be obtained with this technique, which may allow us to screen for malignancies in the whole body.

Patient movement characteristics and the impact on CBCT image quality and interpretability.

PubMed

Spin-Neto, Rubens; Costa, Cláudio; Salgado, Daniela Mra; Zambrana, Nataly Rm; Gotfredsen, Erik; Wenzel, Ann

2018-01-01

To assess the impact of patient movement characteristics and metal/radiopaque materials in the field-of-view (FOV) on CBCT image quality and interpretability. 162 CBCT examinations were performed in 134 consecutive (i.e. prospective data collection) patients (age average: 27.2 years; range: 9-73). An accelerometer-gyroscope system registered patient's head position during examination. The threshold for movement definition was set at ≥0.5-mm movement distance based on accelerometer-gyroscope recording. Movement complexity was defined as uniplanar/multiplanar. Three observers scored independently: presence of stripe (i.e. streak) artefacts (absent/"enamel stripes"/"metal stripes"/"movement stripes"), overall unsharpness (absent/present) and image interpretability (interpretable/not interpretable). Kappa statistics assessed interobserver agreement. χ 2 tests analysed whether movement distance, movement complexity and metal/radiopaque material in the FOV affected image quality and image interpretability. Relevant risk factors (p ≤ 0.20) were entered into a multivariate logistic regression analysis with "not interpretable" as the outcome. Interobserver agreement for image interpretability was good (average = 0.65). Movement distance and presence of metal/radiopaque materials significantly affected image quality and interpretability. There were 22-28 cases, in which the observers stated the image was not interpretable. Small movements (i.e. <3 mm) did not significantly affect image interpretability. For movements ≥ 3 mm, the risk that a case was scored as "not interpretable" was significantly (p ≤ 0.05) increased [OR 3.2-11.3; 95% CI (0.70-65.47)]. Metal/radiopaque material was also a significant (p ≤ 0.05) risk factor (OR 3.61-5.05). Patient movement ≥3 mm and metal/radiopaque material in the FOV significantly affected CBCT image quality and interpretability.

Observer success rates for identification of 3D surface reconstructed facial images and implications for patient privacy and security

NASA Astrophysics Data System (ADS)

Chen, Joseph J.; Siddiqui, Khan M.; Fort, Leslie; Moffitt, Ryan; Juluru, Krishna; Kim, Woojin; Safdar, Nabile; Siegel, Eliot L.

2007-03-01

3D and multi-planar reconstruction of CT images have become indispensable in the routine practice of diagnostic imaging. These tools cannot only enhance our ability to diagnose diseases, but can also assist in therapeutic planning as well. The technology utilized to create these can also render surface reconstructions, which may have the undesired potential of providing sufficient detail to allow recognition of facial features and consequently patient identity, leading to violation of patient privacy rights as described in the HIPAA (Health Insurance Portability and Accountability Act) legislation. The purpose of this study is to evaluate whether 3D reconstructed images of a patient's facial features can indeed be used to reliably or confidently identify that specific patient. Surface reconstructed images of the study participants were created used as candidates for matching with digital photographs of participants. Data analysis was performed to determine the ability of observers to successfully match 3D surface reconstructed images of the face with facial photographs. The amount of time required to perform the match was recorded as well. We also plan to investigate the ability of digital masks or physical drapes to conceal patient identity. The recently expressed concerns over the inability to truly "anonymize" CT (and MRI) studies of the head/face/brain are yet to be tested in a prospective study. We believe that it is important to establish whether these reconstructed images are a "threat" to patient privacy/security and if so, whether minimal interventions from a clinical perspective can substantially reduce this possibility.

ANATOMICAL STUDY OF CRANIAL NERVE EMERGENCE AND SKULL FORAMINA IN THE HORSE USING MAGNETIC RESONANCE IMAGING AND COMPUTED TOMOGRAPHY.

PubMed

Gonçalves, Rita; Malalana, Fernando; McConnell, James Fraser; Maddox, Thomas

2015-01-01

For accurate interpretation of magnetic resonance (MR) images of the equine brain, knowledge of the normal cross-sectional anatomy of the brain and associated structures (such as the cranial nerves) is essential. The purpose of this prospective cadaver study was to describe and compare MRI and computed tomography (CT) anatomy of cranial nerves' origins and associated skull foramina in a sample of five horses. All horses were presented for euthanasia for reasons unrelated to the head. Heads were collected posteuthanasia and T2-weighted MR images were obtained in the transverse, sagittal, and dorsal planes. Thin-slice MR sequences were also acquired using transverse 3D-CISS sequences that allowed mutliplanar reformatting. Transverse thin-slice CT images were acquired and multiplanar reformatting was used to create comparative images. Magnetic resonance imaging consistently allowed visualization of cranial nerves II, V, VII, VIII, and XII in all horses. The cranial nerves III, IV, and VI were identifiable as a group despite difficulties in identification of individual nerves. The group of cranial nerves IX, X, and XI were identified in 4/5 horses although the region where they exited the skull was identified in all cases. The course of nerves II and V could be followed on several slices and the main divisions of cranial nerve V could be distinguished in all cases. In conclusion, CT allowed clear visualization of the skull foramina and occasionally the nerves themselves, facilitating identification of the nerves for comparison with MRI images. © 2015 American College of Veterinary Radiology.

A Novel Imaging Method for the Cartilaginous Eustachian Tube Lumen: Computerized Tomography During the Forced Response Test.

PubMed

Alper, Cuneyt M; Rath, Tanya J; Teixeira, Miriam S; Swarts, J Douglas

2018-01-01

In vivo imaging of the open cartilaginous Eustachian tube (ET) lumen by computed tomography (CT) scan during ET function (ETF) testing to establish new methodology. Five adults underwent unilateral ETF testing of an ear with a nonintact tympanic membrane using the forced response test (FRT) to measure the opening pressure (PO), steady state pressure (PS), and flow conductance (CS). Then at baseline and during the PS phase of the FRT, a temporal-bone CT scan with continuous 0.625 mm thickness was obtained. Multiplanar oblique reformats along the axis of the ET were created, and point value and region of interest (ROI) Hounsfield unit measurements were recorded from the location of the ET lumen. At the FRT flow rate of 11 ml/min, the average PO, PS, and CS were 370.5 daPa, 119.6 daPa, and 0.16 ml/min/daPa, respectively. For flow rates of 23 and 46 ml/min, these values were 236.2, 204.2, 0.12 and 385.5, 321.1, 0.18, respectively. Although areas with lower attenuation were suggestive of air density, a distinct air-filled cartilaginous ET lumen could not be confirmed. While the current imaging parameters failed to resolve the air-soft tissue interface throughout the open cartilaginous ET, further advances in imaging may obviate this limitation.

[Imaging of pelvic organ prolapse].

PubMed

Lapray, Jean-François

2013-01-01

Colpocystodefecography (CCD) and dynamic MRI with defecography (MRId) allow an alternation between filling and emptying the hollow organs and the maximum abdominal strain offered by the defecation. When applied in imaging these two principles reveal the masked or underestimated prolapses at the time of the physical examination. A rigorous application of the technique guarantees almost equivalent results from the two examinations. The CCD provides voiding views and improved analysis of the anorectal pathology (intussusception, anismus) but involves radiation and a more invasive examination. MRId has the advantage of providing continuous visibility of the peritoneal compartment, and a multiplanar representation, enabling an examination of the morphology of the pelvic organs and of the supporting structures, with the disadvantage of still necessitating a supine examination, resulting sometimes in an incomplete or impossible evacuation. The normal and abnormal results (cystoptosis, vaginal vault prolapse, enterocele, anorectal intussuception, rectocele, descending perineum, urinary and fecal incontinence) and the respective advantages and limits of the various imaging methods are detailed. Dynamic perineal and introital ultrasound remains more limited in the appreciation of posterior colpoceles and especially in anorectal disorders, than CCD or MRId. Endoanal ultrasound is the first line morphological evaluation of the anal sphincter. Transvaginal and introital ultrasound can detect some complications of suburethral tapes and meshes. Morphological and dynamic imaging are essential complementary tools to the physical examination, especially when a precise anatomic assessment is required to understand the functional complaint or when a reintervention is needed.

The use of a computed tomographic application for mobile devices in the diagnosis of oral and maxillofacial surgery.

PubMed

Aoki, Eduardo Massaharu; Cortes, Arthur Rodriguez Gonzalez; Arita, Emiko Saito

2015-01-01

The aim of the current technical report was to introduce a computed tomographic (CT) application for mobile devices as a diagnostic tool for analyzing CT images. An iPad and an iPhone (Apple, Cuppertino, CA) were used to navigate through multiplanar reconstructions of cone beam CT scans, using an application derived from the OsiriX CT software. Tools and advantages of this method were recorded. In addition, images rendered in the iPad were manipulated during dental implant placement and grafting procedures to follow up and confirm the implant digital planning in real time. The study population consisted of 10 patients. In all cases, it was possible to use image manipulation tools, such as changing contrast and brightness, zooming, rotating, panning, performing both linear and area measurements, and analyzing gray-scale values of a region of interest. Furthermore, it was possible to use the OsiriX application in the dental clinic where the study was conducted, to follow-up the analyzed implant placement and grafting procedures at the chairside. The current findings suggest that technological and practical methods to visualize radiographic images are invaluable resources to improve training, teaching, networking, and the performance of real-time follow-up of oral and maxillofacial surgical procedures. This article discusses the advantages and disadvantages of introducing this new technology in the clinical routine.

Stress concentration factors at saddle and crown positions on the central brace of two-planar welded CHS DKT-connections

NASA Astrophysics Data System (ADS)

Ahmadi, Hamid; Lotfollahi-Yaghin, Mohammad Ali; Aminfar, Mohammad H.

2012-03-01

A set of parametric stress analyses was carried out for two-planar tubular DKT-joints under different axial loading conditions. The analysis results were used to present general remarks on the effects of the geometrical parameters on stress concentration factors (SCFs) at the inner saddle, outer saddle, and crown positions on the central brace. Based on results of finite element (FE) analysis and through nonlinear regression analysis, a new set of SCF parametric equations was established for fatigue design purposes. An assessment study of equations was conducted against the experimental data and original SCF database. The satisfaction of acceptance criteria proposed by the UK Department of Energy (UK DoE) was also checked. Results of parametric study showed that highly remarkable differences exist between the SCF values in a multi-planar DKT-joint and the corresponding SCFs in an equivalent uni-planar KT-joint having the same geometrical properties. It can be clearly concluded from this observation that using the equations proposed for uni-planar KT-connections to compute the SCFs in multi-planar DKT-joints will lead to either considerably under-predicting or over-predicting results. Hence, it is necessary to develop SCF formulae specially designed for multi-planar DKT-joints. Good results of equation assessment according to UK DoE acceptance criteria, high values of correlation coefficients, and the satisfactory agreement between the predictions of the proposed equations and the experimental data guarantee the accuracy of the equations. Therefore, the developed equations can be reliably used for fatigue design of offshore structures.

Evaluating the utility of 3D TRUS image information in guiding intra-procedure registration for motion compensation

NASA Astrophysics Data System (ADS)

De Silva, Tharindu; Cool, Derek W.; Romagnoli, Cesare; Fenster, Aaron; Ward, Aaron D.

2014-03-01

In targeted 3D transrectal ultrasound (TRUS)-guided biopsy, patient and prostate movement during the procedure can cause target misalignments that hinder accurate sampling of pre-planned suspicious tissue locations. Multiple solutions have been proposed for motion compensation via registration of intra-procedural TRUS images to a baseline 3D TRUS image acquired at the beginning of the biopsy procedure. While 2D TRUS images are widely used for intra-procedural guidance, some solutions utilize richer intra-procedural images such as bi- or multi-planar TRUS or 3D TRUS, acquired by specialized probes. In this work, we measured the impact of such richer intra-procedural imaging on motion compensation accuracy, to evaluate the tradeoff between cost and complexity of intra-procedural imaging versus improved motion compensation. We acquired baseline and intra-procedural 3D TRUS images from 29 patients at standard sextant-template biopsy locations. We used the planes extracted from the 3D intra-procedural scans to simulate 2D and 3D information available in different clinically relevant scenarios for registration. The registration accuracy was evaluated by calculating the target registration error (TRE) using manually identified homologous fiducial markers (micro-calcifications). Our results indicate that TRE improves gradually when the number of intra-procedural imaging planes used in registration is increased. Full 3D TRUS information helps the registration algorithm to robustly converge to more accurate solutions. These results can also inform the design of a fail-safe workflow during motion compensation in a system using a tracked 2D TRUS probe, by prescribing rotational acquisitions that can be performed quickly and easily by the physician immediately prior to needle targeting.

Current Controversies in Diagnosis and Management of Cleft Palate and Velopharyngeal Insufficiency

PubMed Central

Ysunza, Pablo Antonio; Repetto, Gabriela M.; Pamplona, Maria Carmen; Calderon, Juan F.; Shaheen, Kenneth; Chaiyasate, Konkgrit; Rontal, Matthew

2015-01-01

Background. One of the most controversial topics concerning cleft palate is the diagnosis and treatment of velopharyngeal insufficiency (VPI). Objective. This paper reviews current genetic aspects of cleft palate, imaging diagnosis of VPI, the planning of operations for restoring velopharyngeal function during speech, and strategies for speech pathology treatment of articulation disorders in patients with cleft palate. Materials and Methods. An updated review of the scientific literature concerning genetic aspects of cleft palate was carried out. Current strategies for assessing and treating articulation disorders associated with cleft palate were analyzed. Imaging procedures for assessing velopharyngeal closure during speech were reviewed, including a recent method for performing intraoperative videonasopharyngoscopy. Results. Conclusions from the analysis of genetic aspects of syndromic and nonsyndromic cleft palate and their use in its diagnosis and management are presented. Strategies for classifying and treating articulation disorders in patients with cleft palate are presented. Preliminary results of the use of multiplanar videofluoroscopy as an outpatient procedure and intraoperative endoscopy for the planning of operations which aimed to correct VPI are presented. Conclusion. This paper presents current aspects of the diagnosis and management of patients with cleft palate and VPI including 3 main aspects: genetics and genomics, speech pathology and imaging diagnosis, and surgical management. PMID:26273595

Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors.

PubMed

Bhatti, Aftab A; Chugtai, Aamir; Haslam, Philip; Talbot, David; Rix, David A; Soomro, Naeem A

2005-11-01

To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.

CT Arthrography and Virtual Arthroscopy in the Diagnosis of the Anterior Cruciate Ligament and Meniscal Abnormalities of the Knee Joint

PubMed Central

Lee, Whal; Kim, Ho Sung; Kim, Seok Jung; Kim, Hyung Ho; Chung, Jin Wook; Kang, Heung Sik; Choi, Ja-Young

2004-01-01

Objective To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology. Materials and Methods Thirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images. Results The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively. Conclusion CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities. PMID:15064559

Applied Imagistics of Ischaemic Heart a Survey. From the Epidemiology of Stable Angina In Order to Better Prevent Sudden Cardiac Death

NASA Astrophysics Data System (ADS)

Petruse, Radu Emanuil; Batâr, Sergiu; Cojan, Adela; Maniţiu, Ioan

2014-11-01

Coronary computed tomography angiography (CCTA) allows coronary artery visualization and the detection of coronary stenoses. In addition; it has been suggested as a novel, noninvasive modality for coronary atherosclerotic plaque detection, characterization, and quantification. Accurate identification of coronary plaques is challenging, especially for the noncalcified plaques, due to many factors such as the small size of coronary arteries, reconstruction artifacts caused by irregular heartbeats, beam hardening, and partial volume averaging. The development of 16, 32, 64 and the latest 320 row multidetector CT not only increases the spatial and the temporal resolution significantly, but also increases the number of images to be interpreted by radiologists substantially. Radiologists have to visually examine each coronary artery for suspicious stenosis using visualization tools such as multiplanar reformatting (MPR) and curved planar reformatting (CPR) provided by the review workstation in clinical practice

Comparison of CT angiography with conventional arterial angiography in aortoiliac occlusive disease.

PubMed

Tins, B; Oxtoby, J; Patel, S

2001-03-01

This study compared the results of conventional and CT angiography of the aortoiliac segment in 35 patients with occlusive disease. Disease severity was graded into five categories. Two assessors independently assessed the segment from the distal abdominal aorta to the proximal superficial femoral artery and a consensus was formed. There was interobserver agreement in 87% of segments for conventional angiography and in 78% for CT angiography. Comparison of the two modalities gave identical grading in 84% of segments. Dissimilar grading was found in 16%, with a roughly equal number of undergrading and overgrading. CT angiography has the advantages of being minimally invasive, requiring only an intravenous injection of contrast medium and imaging surrounding soft tissues. Multiplanar reconstruction aids the visualization of asymmetrical stenoses, and collateral blood supply is readily appreciated. However, CT angiography may fail to demonstrate short stenoses owing to limited z-axis resolution.

Correlation among ultrasound, cross-sectional anatomy, and histology of the sciatic nerve: a review.

PubMed

Moayeri, Nizar; van Geffen, Geert J; Bruhn, Jörgen; Chan, Vincent W; Groen, Gerbrand J

2010-01-01

Efficient identification of the sciatic nerve (SN) requires a thorough knowledge of its topography in relation to the surrounding structures. Anatomic cross sections in similar oblique planes as observed during SN ultrasonography are lacking. A survey of sonoanatomy matched with ultrasound views of the major SN block sites will be helpful in pattern recognition, especially when combined with images that show the internal architecture of the nerve. From 1 cadaver, consecutive parts of the upper leg corresponding to the 4 major blocks sites were sectioned and deeply frozen. Using cryomicrotomy, consecutive transverse sections were acquired and photographed at 78-microm intervals, along with histologic sections at 5-mm intervals. Multiplanar reformatting was done to reconstruct the optimal planes for an accurate comparison of ultrasonography and gross anatomy. The anatomic and histologic images were matched with ultrasound images that were obtained from 2 healthy volunteers. By simulating the exact position and angulation as in the ultrasonographic images, detailed anatomic overviews of SN and adjacent structures were reconstructed in the gluteal, subgluteal, midfemoral, and popliteal regions. Throughout its trajectory, SN contains numerous fascicles with connective and adipose tissues. In this study, we provide an optimal matching between histology, anatomic cross sections, and short-axis ultrasound images of SN. Reconstructing ultrasonographic planes with this high-resolution digitized anatomy not only enables an overview but also shows detailed views of the architecture of internal SN. The undulating course of the nerve fascicles within SN may explain its varying echogenic appearance during probe manipulation.

Three-dimensional reconstruction of teeth and jaws based on segmentation of CT images using watershed transformation.

PubMed

Naumovich, S S; Naumovich, S A; Goncharenko, V G

2015-01-01

The objective of the present study was the development and clinical testing of a three-dimensional (3D) reconstruction method of teeth and a bone tissue of the jaw on the basis of CT images of the maxillofacial region. 3D reconstruction was performed using the specially designed original software based on watershed transformation. Computed tomograms in digital imaging and communications in medicine format obtained on multispiral CT and CBCT scanners were used for creation of 3D models of teeth and the jaws. The processing algorithm is realized in the stepwise threshold image segmentation with the placement of markers in the mode of a multiplanar projection in areas relating to the teeth and a bone tissue. The developed software initially creates coarse 3D models of the entire dentition and the jaw. Then, certain procedures specify the model of the jaw and cut the dentition into separate teeth. The proper selection of the segmentation threshold is very important for CBCT images having a low contrast and high noise level. The developed semi-automatic algorithm of multispiral and cone beam computed tomogram processing allows 3D models of teeth to be created separating them from a bone tissue of the jaws. The software is easy to install in a dentist's workplace, has an intuitive interface and takes little time in processing. The obtained 3D models can be used for solving a wide range of scientific and clinical tasks.

[Detection of tibial condylar fractures using 3D imaging with a mobile image amplifier (Siemens ISO-C-3D): Comparison with plain films and spiral CT].

PubMed

Kotsianos, D; Rock, C; Wirth, S; Linsenmaier, U; Brandl, R; Fischer, T; Euler, E; Mutschler, W; Pfeifer, K J; Reiser, M

2002-01-01

To analyze a prototype mobile C-arm 3D image amplifier in the detection and classification of experimental tibial condylar fractures with multiplanar reconstructions (MPR). Human knee specimens (n = 22) with tibial condylar fractures were examined with a prototype C-arm (ISO-C-3D, Siemens AG), plain films (CR) and spiral CT (CT). The motorized C-arm provides fluoroscopic images during a 190 degrees orbital rotation computing a 119 mm data cube. From these 3D data sets MP reconstructions were obtained. All images were evaluated by four independent readers for the detection and assessment of fracture lines. All fractures were classified according to the Müller AO classification. To confirm the results, the specimens were finally surgically dissected. 97 % of the tibial condylar fractures were easily seen and correctly classified according to the Müller AO classification on MP reconstruction of the ISO-C-3D. There is no significant difference between ISO-C and CT in detection and correct classification of fractures, but ISO-CD-3D is significant by better than CR. The evaluation of fractures with the ISO-C is better than with plain films alone and comparable to CT scans. The three-dimensional reconstruction of the ISO-C can provide important information which cannot be obtained from plain films. The ISO-C-3D may be useful in planning operative reconstructions and evaluating surgical results in orthopaedic surgery of the limbs.

Intratympanic Iodine Contrast Injection Diffuses Across the Round Window Membrane Allowing for Perilymphatic CT Volume Acquisition Imaging

PubMed Central

Abt, Nicholas B.; Lehar, Mohamed; Guajardo, Carolina Trevino; Penninger, Richard T.; Ward, Bryan K.; Pearl, Monica S.; Carey, John P.

2016-01-01

Hypothesis Whether the RWM is permeable to iodine-based contrast agents (IBCA) is unknown; therefore, our goal was to determine if IBCAs could diffuse through the RWM using CT volume acquisition imaging. Introduction Imaging of hydrops in the living human ear has attracted recent interest. Intratympanic (IT) injection has shown gadolinium's ability to diffuse through the round window membrane (RWM), enhancing the perilymphatic space. Methods Four unfixed human cadaver temporal bones underwent intratympanic IBCA injection using three sequentially studied methods. The first method was direct IT injection. The second method used direct RWM visualization via tympanomeatal flap for IBCA-soaked absorbable gelatin pledget placement. In the third method, the middle ear was filled with contrast after flap elevation. Volume acquisition CT images were obtained immediately post-exposure, and at 1, 6, and 24 hour intervals. Post-processing was accomplished using color ramping and subtraction imaging. Results Following the third method, positive RWM and perilymphatic enhancement were seen with endolymph sparing. Gray scale and color ramp multiplanar reconstructions displayed increased signal within the cochlea compared to pre-contrast imaging. The cochlea was measured for attenuation differences compared to pure water, revealing a pre-injection average of −1,103 HU and a post-injection average of 338 HU. Subtraction imaging shows enhancement remaining within the cochlear space, Eustachian tube, middle ear epithelial lining, and mastoid. Conclusions Iohexol iodine contrast is able to diffuse across the RWM. Volume acquisition CT imaging was able to detect perilymphatic enhancement at 0.5mm slice thickness. The clinical application of IBCA IT injection appears promising but requires further safety studies. PMID:26859543

Percutaneous Vertebroplasty: Preliminary Experiences with Rotational Acquisitions and 3D Reconstructions for Therapy Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodek-Wuerz, Roman; Martin, Jean-Baptiste; Wilhelm, Kai

Percutaneous vertebroplasty (PVP) is carried out under fluoroscopic control in most centers. The exclusion of implant leakage and the assessment of implant distribution might be difficult to assess based on two-dimensional radiographic projection images only. We evaluated the feasibility of performing a follow-up examination after PVP with rotational acquisitions and volumetric reconstructions in the angio suite. Twenty consecutive patients underwent standard PVP procedures under fluoroscopic control. Immediate postprocedure evaluation of the implant distribution in the angio suite (BV 3000; Philips, The Netherlands) was performed using rotational acquisitions (typical parameters for the image acquisition included a 17-cm field-of-view, 200 acquired imagesmore » for a total angular range of 180{sup o}). Postprocessing of acquired volumetric datasets included multiplanar reconstruction (MPR), maximum intensity projection (MIP), and volume rendering technique (VRT) images that were displayed as two-dimensional slabs or as entire three-dimensional volumes. Image evaluation included lesion and implant assessment with special attention given to implant leakage. Findings from rotational acquisitions were compared to findings from postinterventional CT. The time to perform and to postprocess the rotational acquisitions was in all cases less then 10 min. Assessment of implant distribution after PVP using rotational image acquisition methods and volumetric reconstructions was possible in all patients. Cement distribution and potential leakage sites were visualized best on MIP images presented as slabs. From a total of 33 detected leakages with CT, 30 could be correctly detected by rotational image acquisition. Rotational image acquisitions and volumetric reconstruction methods provided a fast method to control radiographically the result of PVP in our cases.« less

Computed tomography of ball pythons (Python regius) in curled recumbency.

PubMed

Hedley, Joanna; Eatwell, Kevin; Schwarz, Tobias

2014-01-01

Anesthesia and tube restraint methods are often required for computed tomography (CT) of snakes due to their natural tendency to curl up. However, these restraint methods may cause animal stress. The aim of this study was to determine whether the CT appearance of the lungs differs for ball pythons in a curled position vs. tube restraint. Whole body CT was performed on ten clinically healthy ball pythons, first in curled and then in straight positions restrained in a tube. Curved multiplanar reformatted (MPR) lung images from curled position scans were compared with standard MPR lung images from straight position scans. Lung attenuation and thickness were measured at three locations for each scan. Time for positioning and scanning was 12 ± 5 min shorter for curled snakes compared to tube restraint. Lung parenchyma thickness and attenuation declined from cranial to caudal on both straight and curled position images. Mean lung parenchyma thickness was greater in curled images at locations 1 (P = 0.048) and 3 (P = 0.044). Mean lung parenchyma thickness decreased between location 1 and 2 by 86-87% (straight: curled) and between location 1 and 3 by 51-50% (straight: curled). Mean lung attenuation at location 1 was significantly greater on curled position images than tube restraint images (P = 0.043). Findings indicated that CT evaluation of the lungs is feasible for ball pythons positioned in curled recumbency if curved MPR is available. However, lung parenchyma thickness and attenuation in some locations may vary from those acquired using tube restraint. © 2014 American College of Veterinary Radiology.

Safe Corridor to Access Clivus for Endoscopic Trans-Sphenoidal Surgery: A Radiological and Anatomical Study

PubMed Central

Cheng, Ye; Zhang, Siwen; Chen, Yong; Zhao, Gang

2015-01-01

Purpose Penetration of the clivus is required for surgical access of the brain stem. The endoscopic transclivus approach is a difficult procedure with high risk of injury to important neurovascular structures. We undertook a novel anatomical and radiological investigation to understand the structure of the clivus and neurovascular structures relevant to the extended trans-nasal trans-sphenoid procedure and determine a safe corridor for the penetration of the clivus. Method We examined the clivus region in the computed tomographic angiography (CTA) images of 220 adults, magnetic resonance (MR) images of 50 adults, and dry skull specimens of 10 adults. Multiplanar reconstruction (MPR) of the CT images was performed, and the anatomical features of the clivus were studied in the coronal, sagittal, and axial planes. The data from the images were used to determine the anatomical parameters of the clivus and neurovascular structures, such as the internal carotid artery and inferior petrosal sinus. Results The examination of the CTA and MR images of the enrolled subjects revealed that the thickness of the clivus helped determine the depth of the penetration, while the distance from the sagittal midline to the important neurovascular structures determined the width of the penetration. Further, data from the CTA and MR images were consistent with those retrieved from the examination of the cadaveric specimens. Conclusion Our findings provided certain pointers that may be useful in guiding the surgery such that inadvertent injury to vital structures is avoided and also provided supportive information for the choice of the appropriate endoscopic equipment. PMID:26368821

Multiplanar lumbopelvic control in patients with low back pain: is multiplanar assessment better than single plane assessment in discriminating between patients and healthy controls?

PubMed

Nelson-Wong, E; Gallant, P; Alexander, S; Dehmer, K; Ingvalson, S; McClenahan, B; Piatte, A; Poupore, K; Davis, A M

2016-02-01

Patients with low back pain (LBP) commonly have lumbopelvic control deficits. Lumbopelvic assessment during sagittal motion is incorporated into commonly used clinical examination algorithms for Treatment Based Classification. The purpose of this study was to investigate whether combined assessment of lumbopelvic control during sagittal and frontal plane motion discriminates between people with and without LBP better than single plane assessment alone. Nineteen patients with LBP and 18 healthy control participants volunteered for this study. The active straight leg raise (ASLR) and active hip abduction (AHAbd) tests were used to assess lumbopelvic control during sagittal and frontal plane motion, respectively. The tests were scored as positive or negative using published scoring criteria. Contingency tables were created for each test alone and for the combined tests (both positive/both negative) with presence/absence of LBP as the reference standard to calculate accuracy statistics of sensitivity (sn), specificity (sp), likelihood (+LR and -LR), and diagnostic odds ratios (OR). Active straight leg raise and AHAbd tests alone had sn of 0·63, 0·74, respectively, sp of 0·61, 0·50, respectively, and OR of 2·7, 2·8, respectively. The combined tests had sn = 0·89, sp = 0·60, and OR = 12·0. Forty percent of patients with LBP had control deficits in both planes of motion. The AHAbd and ALSR tests appear to have greater diagnostic discrimination when used in combination than when used independently. A percentage of patients with LBP had control deficits in both planes, while others demonstrated uniplanar deficits only. These findings highlight the importance of multiplanar assessment in patients with LBP.

A comparative study of cranial, blunt trauma fractures as seen at medicolegal autopsy and by Computed Tomography

PubMed Central

2009-01-01

Background Computed Tomography (CT) has become a widely used supplement to medico legal autopsies at several forensic institutes. Amongst other things, it has proven to be very valuable in visualising fractures of the cranium. Also CT scan data are being used to create head models for biomechanical trauma analysis by Finite Element Analysis. If CT scan data are to be used for creating individual head models for retrograde trauma analysis in the future we need to ascertain how well cranial fractures are captured by CT scan. The purpose of this study was to compare the diagnostic agreement between CT and autopsy regarding cranial fractures and especially the precision with which cranial fractures are recorded. Methods The autopsy fracture diagnosis was compared to the diagnosis of two CT readings (reconstructed with Multiplanar and Maximum Intensity Projection reconstructions) by registering the fractures on schematic drawings. The extent of the fractures was quantified by merging 3-dimensional datasets from both the autopsy as input by 3D digitizer tracing and CT scan. Results The results showed a good diagnostic agreement regarding fractures localised in the posterior fossa, while the fracture diagnosis in the medial and anterior fossa was difficult at the first CT scan reading. The fracture diagnosis improved during the second CT scan reading. Thus using two different CT reconstructions improved diagnosis in the medial fossa and at the impact points in the cranial vault. However, fracture diagnosis in the anterior and medial fossa and of hairline fractures in general still remained difficult. Conclusion The study showed that the forensically important fracture systems to a large extent were diagnosed on CT images using Multiplanar and Maximum Intensity Projection reconstructions. Difficulties remained in the minute diagnosis of hairline fractures. These inconsistencies need to be resolved in order to use CT scan data of victims for individual head modelling and trauma analysis. PMID:19835570

Three-dimensional constructive interference in steady-state magnetic resonance imaging in syringomyelia: advantages over conventional imaging.

PubMed

Roser, Florian; Ebner, Florian H; Danz, Søren; Riether, Felix; Ritz, Rainer; Dietz, Klaus; Naegele, Thomas; Tatagiba, Marcos S

2008-05-01

Neuroradiology has become indispensable in detecting the pathophysiology in syringomyelia. Constructive interference in steady-state (CISS) magnetic resonance (MR) imaging can provide superior contrast at the sub-arachnoid tissue borders. As this region is critical in preoperative evaluation, the authors hypothesized that CISS imaging would provide superior assessment of syrinx pathology and surgical planning. Based on records collected from a database of 130 patients with syringomyelia treated at the authors' institution, 59 patients were prospectively evaluated with complete neuroradiological examinations. In addition to routine acquisitions with FLAIR, T1- and T2-weighted, and contrast-enhanced MR imaging series, the authors obtained sagittal cardiac-gated sequences to visualize cerebrospinal fluid (CSF) pulsations and axial 3D CISS MR sequences to detect focal arachnoid webs. Statistical qualitative and quantitative evaluations of spinal cord/CSF contrast, spinal cord/CSF delineation, motion artifacts, and artifacts induced by pulsatile CSF flow were performed. The 3D CISS MR sequences demonstrated a contrast-to-noise ratio significantly better than any other routine imaging sequence (p < 0.001). Moreover, 3D CISS imaging can detect more subarachnoid webs and cavitations in the syrinx than T2-weighted MR imaging with less flow-void artifact. The limitation of 3D CISS imaging is a susceptibility to motion artifacts that can cause reduced spatial resolution. Lengthy acquisition times for axial segments can be reduced with multiplanar reconstruction of 3D CISS-generated sagittal images. Constructive interference in steady-state imaging is the MR sequence of choice in the preoperative evaluation of syringomyelia, allowing significantly higher detection rates of focal subarachnoid webs, whereas standard T2-weighted MR imaging shows turbulent CSF flow voids. Constructive interference in steady-state MR imaging enables the neurosurgeon to accurately identify cases requiring decompression for obstructed CSF. Motion artifacts can be eliminated with technical variations.

Use of real time three-dimensional transesophageal echocardiography in intracardiac catheter based interventions.

PubMed

Perk, Gila; Lang, Roberto M; Garcia-Fernandez, Miguel Angel; Lodato, Joe; Sugeng, Lissa; Lopez, John; Knight, Brad P; Messika-Zeitoun, David; Shah, Sanjiv; Slater, James; Brochet, Eric; Varkey, Mathew; Hijazi, Ziyad; Marino, Nino; Ruiz, Carlos; Kronzon, Itzhak

2009-08-01

Real-time three-dimensional (RT3D) echocardiography is a recently developed technique that is being increasingly used in echocardiography laboratories. Over the past several years, improvements in transducer technologies have allowed development of a full matrix-array transducer that allows acquisition of pyramidal-shaped data sets. These data sets can be processed online and offline to allow accurate evaluation of cardiac structures, volumes, and mass. More recently, a transesophageal transducer with RT3D capabilities has been developed. This allows acquisition of high-quality RT3D images on transesophageal echocardiography (TEE). Percutaneous catheter-based procedures have gained growing acceptance in the cardiac procedural armamentarium. Advances in technology and technical skills allow increasingly complex procedures to be performed using a catheter-based approach, thus obviating the need for open-heart surgery. The authors used RT3D TEE to guide 72 catheter-based cardiac interventions. The procedures included the occlusion of atrial septal defects or patent foramen ovales (n=25), percutaneous mitral valve repair (e-valve clipping; n=3), mitral balloon valvuloplasty for mitral stenosis (n=10), left atrial appendage obliteration (n=11), left atrial or pulmonary vein ablation for atrial fibrillation (n=5), percutaneous closures of prosthetic valve dehiscence (n=10), percutaneous aortic valve replacement (n=6), and percutaneous closures of ventricular septal defects (n=2). In this review, the authors describe their experience with this technique, the added value over multiplanar two-dimensional TEE, and the pitfalls that were encountered. The main advantages found for the use RT3D TEE during catheter-based interventions were (1) the ability to visualize the entire lengths of intracardiac catheters, including the tips of all catheters and the balloons or devices they carry, along with a clear depiction of their positions in relation to other cardiac structures, and (2) the ability to ability to demonstrate certain structures in an "en face" view, which is not offered by any other currently available real-time imaging technique, enabling appreciation of the exact nature of the lesion that is undergoing intervention. RT3D TEE is a powerful new imaging tool that may become the technique of choice and the standard of care for guidance of selected percutaneous catheter-based procedures.

[Virtual endoscopic navigation and body transparency based on computed tomography. A step towards in vivo imaging].

PubMed

Cabanis, Emmanuel-Alain; Gombergh, Rodolphe; Castro, Albert; Gandjbakhch, Iradj; Iba-Zizen, Marie-Thérèse; Dubois, François

2011-06-01

Progress in HR-CTdata processing has led to lower X-ray exposure and to better diagnostic performance. We describe 19 adult patients (among 5000) examined by HR CT with 64 detectors, acquisition and exposure protocols in mSv, spiral, 0.6-mm slices, 5To PACS. After the two usual processing steps (60 gray values, 5122 and 10242 matrices, dedicated workstations for coronaroscopy and virtual coloscopy, 2D multiplanar reformation, surfacic, 3D volumes with dissection and navigation), a third original data processing step on additional workstations was added. Variable matrix extrapolated images, flexible colored curves (different from anatomical conventions), lighting (sources) and transparencies (unavailable with traditional endoscopy) were used. The digital film is a 16-minute "journey "consisting of 19 endo-body navigations in 5 regions, from the head to the bronchi, from the heart to the coronary arteries, and from the digestive tract to the abdomen and pelvis. One possible application is post-operative verification of an aortic graft. The movie is illustrated here with ten plates. This new approach is cost-effective and beneficial for the patient, in terms of early diagnosis and therapeutic follow-up. Ethical issues are also examined.

Contrast-Enhanced Abdominal Angiographic CT for Intra-abdominal Tumor Embolization: A New Tool for Vessel and Soft Tissue Visualization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, Bernhard Christian, E-mail: bernhard.meyer@charite.de; Frericks, Bernd Benedikt; Albrecht, Thomas

2007-07-15

C-Arm cone-beam computed tomography (CACT), is a relatively new technique that uses data acquired with a flat-panel detector C-arm angiography system during an interventional procedure to reconstruct CT-like images. The purpose of this Technical Note is to present the technique, feasibility, and added value of CACT in five patients who underwent abdominal transarterial chemoembolization procedures. Target organs for the chemoembolizations were kidney, liver, and pancreas and a liposarcoma infiltrating the duodenum. The time for patient positioning, C-arm and system preparation, CACT raw data acquisition, and data reconstruction for a single CACT study ranged from 6 to 12 min. The volumemore » data set produced by the workstation was interactively reformatted using maximum intensity projections and multiplanar reconstructions. As part of an angiography system CACT provided essential information on vascular anatomy, therapy endpoints, and immediate follow-up during and immediately after the abdominal interventions without patient transfer. The quality of CACT images was sufficient to influence the course of treatment. This technology has the potential to expedite any interventional procedure that requires three-dimensional information and navigation.« less

MDCT in the evaluation of skeletal trauma: principles, protocols, and clinical applications.

PubMed

Geijer, Mats; El-Khoury, Georges Y

2006-10-01

Multidetector computed tomography (MDCT) scanners have made volume imaging possible and are used extensively to study polytrauma patients, especially in the evaluation of the spine and peripheral skeleton. An MDCT scanner coupled with a modern workstation has become an essential diagnostic tool for any emergency department. Familiarity with the basic physical principles of MDCT such as projection data, section collimation, and beam collimation is important to achieve high-quality imaging while keeping unnecessary radiation to a minimum. After a polytrauma MDCT examination, images can be reconstructed to obtain different slice thickness, slice interval, fields of view, or reconstruction kernels. No additional scanning is needed for imaging the thoracolumbar spine or bony pelvis. High-quality multiplanar reformation (MPR) and three-dimensional (3-D) images can be created at the workstation using the volumetric data. However, MDCT is a high-dose examination, and care should be taken to use as low a dose as possible. In the musculoskeletal system, MDCT has long been used for evaluation of spinal and pelvic trauma; however, the frequency of its use in extremity trauma has been low. In the extremities, radiography seems to underestimate the extent and severity of injury, especially in complex areas such as the shoulder, elbow, wrist, knee, and ankle. MDCT in the extremities is helpful in fracture detection, evaluation, characterization, and treatment planning. The MPR images give excellent structural detail, and the 3-D images help in understanding the spatial relations, which is important for fracture classification and for preoperative planning. MDCT is also helpful in the follow-up of postoperative results, even in the presence of hardware. Tendon injuries can also be evaluated with MDCT.

[Prenatal diagnosis of isolated otocefalia. Usefulness of three-dimensional ultrasound].

PubMed

Escribano Abad, David; Arbués Gabarre, Juan; Gómez Montes, Enery; Puente Agueda, José Manuel; Herraiz García, Ignacio; Galindo Izquierdo, Alberto

2011-08-01

Otocephaly is a rare and lethal congenital malformation characterized by the presence of agnathia, microstomia, aglossia and synotia. Despite its frequent association with severe malformations, diagnosis in the few published cases is usually made at III trimester. In this case, three-dimensional ultrasound scan was performed in a Chinese primigravida with no remarkable personal nor familiar history since mandible was difficulty visualized with two-dimensional sonography at 21 weeks of gestation. Multiplanar and rendering mode showed the typical cervicofacial features of otocephaly without associated malformations. After parental counselling, they opted for termination of pregnancy and necropsy confirmed our prenatal findings. Our case shows the usefulness of three-dimensional ultrasound in assessing fetal cervicofacial pathology. Volumetric capture allows a delayed study of fetal anatomy and multiplanar mode offers the reconstruction of views whose achivement is difficult with conventional 2D ultrasound. Surface rendering provides excellent spatial vision and enables parents to understand the severity of the malformation thus helping with their decisions.

[Efficacy of high-resolution CT in differential diagnosis of chronic suppurative otitis media and cholesteatoma otitis media by soft-tissue shadows].

PubMed

Sun, Xiao-wei; Zhang, Jian-ji; Ding, Yuan-ping; Dou, Fen-fen; Zhang, Han-bing; Gong, Ke-bo; Xu, An-ting

2011-05-01

To evalute the efficacy of high-resolution CT(HRCT) in differential diagnosis and treatment of chronic suppurative otitis media and cholesteatoma otitis media by soft-tissue shadows. HRCT scanning was performed in 120 cases, 153 ears, with chronic otitis suppurative media and cholesteatoma otitis media, of which original data were processed with multi-planar reconstruction (MPR) and maximum intensity projection (MIP), the characteristics of the soft-tissue shadows' growth, window width or window leveling and bony destruction were respectively observed, as well as compared with the surgery findings. In 120 patients (153 ears), 109 ears were diagnosed as cholesteatoma otitis media, and 44 ears were diagnosed as chronic suppurative otitis media, among which 33 ears had granulation tissue and 11 ears had secretion. One hundred and seven ears were postoperatively diagnosed as cholesteatoma otitis media, among which 25 ears had granulation tissue. Among 46 ears of chronic suppurative otitis media, 35 ears had granulation tissue, and only 11 ears had secretion. A 98.6% diagnostic accuracy can be reached with HRCT in diagnosing cholesteatoma otitis media and chronic suppurative otitis media. The Youden's index was 0.98, 0.98 and 1.00 respectively with HRCT in diagnosing cholesteatoma, granulation tissue and secretion. Combination of the three different imaging methods, axial images, coronal MPR images and MIP images, can improve the efficacy of the HRCT diagnosis and definite chronic otitis media, which can be routinely used for surgery plan.

Rotation of the vermis as a cause of enlarged cisterna magna on prenatal imaging.

PubMed

Zalel, Y; Gilboa, Y; Gabis, L; Ben-Sira, L; Hoffman, C; Wiener, Y; Achiron, R

2006-05-01

Dandy-Walker complex is a continuum of developmental anomalies of the posterior fossa which includes vermian rotation. However, vermian rotation alone may be benign. The aim of this study was to describe our experience with sagittal-plane prenatal ultrasound in the diagnosis of rotation of the vermis in cases of suspected enlarged cisterna magna on routine antenatal imaging, and to describe the follow-up of these patients. Seven women, who were referred to our ultrasound unit for evaluation of an enlarged fetal cisterna magna and suspected agenesis of the vermis on axial-plane imaging, underwent further multiplanar studies of the posterior fossa and measurements of the vermis. The mean maternal age was 27 (range, 20-33) years and the mean gestational age at diagnosis was 19.5 (range, 18-31) weeks. The standard axial plane image showed a 'direct communication' between the cisterna magna and the fourth ventricle. In the mid-sagittal plane, the vermis was clearly delineated, with posterosuperior rotation. Vermis size was within normal limits for gestational age in all cases. Findings were confirmed by prenatal magnetic resonance imaging (MRI) in two cases and postnatal MRI and/or sonography in five. During a mean follow-up of 4.5 (range, 1-7.5) years, all children developed normally, with no neurological complications. The finding of an enlarged cisterna magna on standard- (axial-)plane ultrasound should be evaluated further in the sagittal plane to determine whether the cause is rotation of a normal vermis. This may spare patients unnecessary tests, anxiety and, in some cases, pregnancy termination. Copyright 2006 ISUOG

Image quality of iterative reconstruction in cranial CT imaging: comparison of model-based iterative reconstruction (MBIR) and adaptive statistical iterative reconstruction (ASiR).

PubMed

Notohamiprodjo, S; Deak, Z; Meurer, F; Maertz, F; Mueck, F G; Geyer, L L; Wirth, S

2015-01-01

The purpose of this study was to compare cranial CT (CCT) image quality (IQ) of the MBIR algorithm with standard iterative reconstruction (ASiR). In this institutional review board (IRB)-approved study, raw data sets of 100 unenhanced CCT examinations (120 kV, 50-260 mAs, 20 mm collimation, 0.984 pitch) were reconstructed with both ASiR and MBIR. Signal-to-noise (SNR) and contrast-to-noise (CNR) were calculated from attenuation values measured in caudate nucleus, frontal white matter, anterior ventricle horn, fourth ventricle, and pons. Two radiologists, who were blinded to the reconstruction algorithms, evaluated anonymized multiplanar reformations of 2.5 mm with respect to depiction of different parenchymal structures and impact of artefacts on IQ with a five-point scale (0: unacceptable, 1: less than average, 2: average, 3: above average, 4: excellent). MBIR decreased artefacts more effectively than ASiR (p < 0.01). The median depiction score for MBIR was 3, whereas the median value for ASiR was 2 (p < 0.01). SNR and CNR were significantly higher in MBIR than ASiR (p < 0.01). MBIR showed significant improvement of IQ parameters compared to ASiR. As CCT is an examination that is frequently required, the use of MBIR may allow for substantial reduction of radiation exposure caused by medical diagnostics. • Model-Based iterative reconstruction (MBIR) effectively decreased artefacts in cranial CT. • MBIR reconstructed images were rated with significantly higher scores for image quality. • Model-Based iterative reconstruction may allow reduced-dose diagnostic examination protocols.

Application of a dual-resolution voxelization scheme to compressed-sensing (CS)-based iterative reconstruction in digital tomosynthesis (DTS)

NASA Astrophysics Data System (ADS)

Park, S. Y.; Kim, G. A.; Cho, H. S.; Park, C. K.; Lee, D. Y.; Lim, H. W.; Lee, H. W.; Kim, K. S.; Kang, S. Y.; Park, J. E.; Kim, W. S.; Jeon, D. H.; Je, U. K.; Woo, T. H.; Oh, J. E.

2018-02-01

In recent digital tomosynthesis (DTS), iterative reconstruction methods are often used owing to the potential to provide multiplanar images of superior image quality to conventional filtered-backprojection (FBP)-based methods. However, they require enormous computational cost in the iterative process, which has still been an obstacle to put them to practical use. In this work, we propose a new DTS reconstruction method incorporated with a dual-resolution voxelization scheme in attempt to overcome these difficulties, in which the voxels outside a small region-of-interest (ROI) containing target diagnosis are binned by 2 × 2 × 2 while the voxels inside the ROI remain unbinned. We considered a compressed-sensing (CS)-based iterative algorithm with a dual-constraint strategy for more accurate DTS reconstruction. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate its viability. Our results indicate that the proposed method seems to be effective for reducing computational cost considerably in iterative DTS reconstruction, keeping the image quality inside the ROI not much degraded. A binning size of 2 × 2 × 2 required only about 31.9% computational memory and about 2.6% reconstruction time, compared to those for no binning case. The reconstruction quality was evaluated in terms of the root-mean-square error (RMSE), the contrast-to-noise ratio (CNR), and the universal-quality index (UQI).

Detection of biliary and vascular anatomy in living liver donors: value of gadobenate dimeglumine enhanced MR and MDCT angiography.

PubMed

Artioli, Diana; Tagliabue, Marianna; Aseni, Paolo; Sironi, Sandro; Vanzulli, Angelo

2010-11-01

To evaluate the performance of magnetic resonance (MR) and multidetector computed tomography (MDCT) in the assessment of living donor's vascular and biliary anatomy, having surgical findings as reference standard. Thirty-two living liver donors underwent MR cholangiography (1.5-T; standard cholangiography pulse sequences and delayed acquisitions after administration of biliary contrast agent) for biliary anatomy evaluation. MDCT (16-row multidetector scanner, multiphase protocol, 3mm slice thickness) was also performed in all cases for the assessment of vascular anatomy before transplantation. Hepatic veins (<4mm in diameter) were not considered. MR and MDCT images interpretation was performed by two reviewers by consensus, based on source axial images, multiplanar reformats, and three-dimensional (3D) postprocessing images. Surgical intraoperative findings were used as standard of reference. At surgery, 17 biliary anomalies, 3 portal anomalies, 32 venous and 8 arterial variants were found in the 32 patients. MR correctly identified 15/17 biliary anomalies, with a sensitivity of 88% and a specificity of 93%. MDCT correctly identified 8/8 arterial, 3/3 portal and 29/32 venous variants, with a sensitivity of 100% and 91%, respectively, and a specificity of 100%. MR and MDCT proved to be efficient in evaluating living liver donor's biliary and vascular anatomy. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Three-dimensional Image Fusion Guidance for Transjugular Intrahepatic Portosystemic Shunt Placement.

PubMed

Tacher, Vania; Petit, Arthur; Derbel, Haytham; Novelli, Luigi; Vitellius, Manuel; Ridouani, Fourat; Luciani, Alain; Rahmouni, Alain; Duvoux, Christophe; Salloum, Chady; Chiaradia, Mélanie; Kobeiter, Hicham

2017-11-01

To assess the safety, feasibility and effectiveness of image fusion guidance with pre-procedural portal phase computed tomography with intraprocedural fluoroscopy for transjugular intrahepatic portosystemic shunt (TIPS) placement. All consecutive cirrhotic patients presenting at our interventional unit for TIPS creation from January 2015 to January 2016 were prospectively enrolled. Procedures were performed under general anesthesia in an interventional suite equipped with flat panel detector, cone-beam computed tomography (CBCT) and image fusion technique. All TIPSs were placed under image fusion guidance. After hepatic vein catheterization, an unenhanced CBCT acquisition was performed and co-registered with the pre-procedural portal phase CT images. A virtual path between hepatic vein and portal branch was made using the virtual needle path trajectory software. Subsequently, the 3D virtual path was overlaid on 2D fluoroscopy for guidance during portal branch cannulation. Safety, feasibility, effectiveness and per-procedural data were evaluated. Sixteen patients (12 males; median age 56 years) were included. Procedures were technically feasible in 15 of the 16 patients (94%). One procedure was aborted due to hepatic vein catheterization failure related to severe liver distortion. No periprocedural complications occurred within 48 h of the procedure. The median dose-area product was 91 Gy cm 2 , fluoroscopy time 15 min, procedure time 40 min and contrast media consumption 65 mL. Clinical benefit of the TIPS placement was observed in nine patients (56%). This study suggests that 3D image fusion guidance for TIPS is feasible, safe and effective. By identifying virtual needle path, CBCT enables real-time multiplanar guidance and may facilitate TIPS placement.

Interventional spinal procedures guided and controlled by a 3D rotational angiographic unit.

PubMed

Pedicelli, Alessandro; Verdolotti, Tommaso; Pompucci, Angelo; Desiderio, Flora; D'Argento, Francesco; Colosimo, Cesare; Bonomo, Lorenzo

2011-12-01

The aim of this paper is to demonstrate the usefulness of 2D multiplanar reformatting images (MPR) obtained from rotational acquisitions with cone-beam computed tomography technology during percutaneous extra-vascular spinal procedures performed in the angiography suite. We used a 3D rotational angiographic unit with a flat panel detector. MPR images were obtained from a rotational acquisition of 8 s (240 images at 30 fps), tube rotation of 180° and after post-processing of 5 s by a local work-station. Multislice CT (MSCT) is the best guidance system for spinal approaches permitting direct tomographic visualization of each spinal structure. Many operators, however, are trained with fluoroscopy, it is less expensive, allows real-time guidance, and in many centers the angiography suite is more frequently available for percutaneous procedures. We present our 6-year experience in fluoroscopy-guided spinal procedures, which were performed under different conditions using MPR images. We illustrate cases of vertebroplasty, epidural injections, selective foraminal nerve root block, facet block, percutaneous treatment of disc herniation and spine biopsy, all performed with the help of MPR images for guidance and control in the event of difficult or anatomically complex access. The integrated use of "CT-like" MPR images allows the execution of spinal procedures under fluoroscopy guidance alone in all cases of dorso-lumbar access, with evident limitation of risks and complications, and without need for recourse to MSCT guidance, thus eliminating CT-room time (often bearing high diagnostic charges), and avoiding organizational problems for procedures that need, for example, combined use of a C-arm in the CT room.

State-of-the-Art Diagnosis and Treatment of Melanoma: Optimal Multidetector Computed Tomographic Practice to Identify Metastatic Disease and Review of Innovative Therapeutic Agents.

PubMed

Jones, Blake C; Lipson, Evan J; Childers, Brandon; Fishman, Elliot K; Johnson, Pamela T

The incidence of melanoma has risen dramatically over the past several decades. Oncologists rely on the ability of radiologists to identify subtle radiographic changes representing metastatic and recurrent melanoma in uncommon locations on multidetector computed tomography (MDCT) as the front-line imaging surveillance tool. To accomplish this goal, MDCT acquisition and display must be optimized and radiologist interpretation and search patterns must be tailored to identify the unique and often subtle metastatic lesions of melanoma. This article describes MDCT acquisition and display techniques that optimize the visibility of melanoma lesions, such as high-contrast display windows and multiplanar reconstructions. In addition, innovative therapies for melanoma, such as immunotherapy and small-molecule therapy, have altered clinical management and outcomes and have also changed the spectrum of therapeutic complications that can be detected on MDCT. Recent advances in melanoma therapy and potential complications that the radiologist can identify on MDCT are reviewed.

Laparoscopic radical nephrectomy for a right renal tumor with renal vein tumor thrombus in a patient with situs inversus totalis.

PubMed

Ito, Jun; Kaiho, Yasuhiro; Iwamura, Hiromichi; Anan, Go; Sato, Makoto

2018-05-23

Situs inversus totalis (SIT) is a rare congenital anomaly characterized by complete inversion of the thoracic and abdominal organs. Many intra-abdominal and vessel anomalies have been reported in association with SIT. However, there have been no reports on the use of laparoscopic radical nephrectomy with thrombectomy for renal vein thrombus, which is considered as a safe and feasible procedure, in patients with SIT. We herein present the case of an 80-year-old man with SIT who was preoperatively diagnosed with a right renal tumor and renal vein tumor thrombus. The patient underwent laparoscopic right nephrectomy and tumor thrombectomy with no intraoperative complications. To ensure a safe procedure, the anatomy and vessels were carefully evaluated preoperatively using 3-D multiplanar reconstructed CT imaging. Assessing anatomical structures leads to safer laparoscopic radical nephrectomy for renal cell carcinoma with venous tumor thrombus in patients with SIT. © 2018 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and John Wiley & Sons Australia, Ltd.

Radiation from mixed multi-planar wire arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.

2014-03-15

The study of radiation from different wire materials in wire array Z-pinch plasma is a very challenging topic because it is almost impossible to separate different plasmas at the stagnation. A new approach is suggested based on planar wire array (PWA) loads to assess this problem. Multi-planar wire arrays are implemented that consist of few planes, each with the same number of wires and masses but from different wire materials, arranged in parallel rows. In particular, the experimental results obtained with triple PWAs (TPWAs) on the UNR Zebra generator are analyzed with Wire Ablation Dynamics Model, non-local thermodynamic equilibrium kineticmore » model, and 2D radiation magneto-hydrodynamic to illustrate this new approach. In TPWAs, two wire planes were from mid-atomic-number wire material and another plane was from alloyed Al, placed either in the middle or at the edge of the TPWA. Spatial and temporal properties of K-shell Al and L-shell Cu radiations were analyzed and compared from these two configurations of TPWAs. Advantages of the new approach are demonstrated and future work is discussed.« less

The angulation of the septal structures impacts ventricular imbalance in atrioventricular septal defects with a common atrioventricular junction.

PubMed

Ahmad, Zaheer; Lim, Zek; Roman, Kevin; Haw, Marcus; Anderson, Robert H; Vettukattil, Joseph

2016-02-01

Multiplanar re-formatting of full-volume three-dimensional echocardiography data sets offers new insights into the morphology of atrioventricular septal defects. We hypothesised that distortion of the alignment between the atrial and ventricular septums results in imbalanced venous return to the ventricles, with consequent proportional ventricular hypoplasia. A single observer evaluated 31 patients, with a mean age of 52.09 months, standard deviation of 55, and with a range from 2 to 264 months, with atrioventricular septal defects, of whom 17 were boys. Ventricular imbalance, observed in nine patients, was determined by two-dimensional assessment, and confirmed at surgical inspection in selected cases when a univentricular strategy was undertaken. Offline analysis using multiplanar re-formatting was performed. A line was drawn though the length of the ventricular septum and a second line along the plane of the atrial septum, taking the angle between these two lines as the atrioventricular septal angle. We compared the angle between 22 patients with adequately sized ventricles, and those with ventricular imbalance undergoing univentricular repair. In the 22 patients undergoing biventricular repair, the septal angle was 0 in 14 patients; the other eight patients having angles ranging from 1 to 36, with a mean angle of 7.4°, and standard deviation of 11.1°.The mean angle in the nine patients with ventricle imbalance was 28.6°, with a standard deviation of 3.04°, and with a range from 26 to 35°. Of those undergoing univentricular repair, two patients died, with angles of 26 and 30°, respectively. The atrioventricular septal angle derived via multiplanar formatting gives important information regarding the degree of ventricular hypoplasia and imbalance. When this angle is above 25°, patients are likely to have ventricular imbalance requiring univentricular repair.

Anatomy of the clitoris.

PubMed

O'Connell, Helen E; Sanjeevan, Kalavampara V; Hutson, John M

2005-10-01

We present a comprehensive account of clitoral anatomy, including its component structures, neurovascular supply, relationship to adjacent structures (the urethra, vagina and vestibular glands, and connective tissue supports), histology and immunohistochemistry. We related recent anatomical findings to the historical literature to determine when data on accurate anatomy became available. An extensive review of the current and historical literature was done. The studies reviewed included dissection and microdissection, magnetic resonance imaging (MRI), 3-dimensional sectional anatomy reconstruction, histology and immunohistochemical studies. The clitoris is a multiplanar structure with a broad attachment to the pubic arch and via extensive supporting tissue to the mons pubis and labia. Centrally it is attached to the urethra and vagina. Its components include the erectile bodies (paired bulbs and paired corpora, which are continuous with the crura) and the glans clitoris. The glans is a midline, densely neural, non-erectile structure that is the only external manifestation of the clitoris. All other components are composed of erectile tissue with the composition of the bulbar erectile tissue differing from that of the corpora. The clitoral and perineal neurovascular bundles are large, paired terminations of the pudendal neurovascular bundles. The clitoral neurovascular bundles ascend along the ischiopubic rami to meet each other and pass along the superior surface of the clitoral body supplying the clitoris. The neural trunks pass largely intact into the glans. These nerves are at least 2 mm in diameter even in infancy. The cavernous or autonomic neural anatomy is microscopic and difficult to define consistently. MRI complements dissection studies and clarifies the anatomy. Clitoral pharmacology and histology appears to parallel those of penile tissue, although the clinical impact is vastly different. Typical textbook descriptions of the clitoris lack detail and include inaccuracies. It is impossible to convey clitoral anatomy in a single diagram showing only 1 plane, as is typically provided in textbooks, which reveal it as a flat structure. MRI provides a multiplanar representation of clitoral anatomy in the live state, which is a major advantage, and complements dissection materials. The work of Kobelt in the early 19th century provides a most comprehensive and accurate description of clitoral anatomy, and modern study provides objective images and few novel findings. The bulbs appear to be part of the clitoris. They are spongy in character and in continuity with the other parts of the clitoris. The distal urethra and vagina are intimately related structures, although they are not erectile in character. They form a tissue cluster with the clitoris. This cluster appears to be the locus of female sexual function and orgasm.

A Fast 3-Dimensional Magnetic Resonance Imaging Reconstruction for Surgical Planning of Uterine Myomectomy

PubMed Central

2017-01-01

Background Uterine myoma is the most common benign gynecologic tumor in reproductive-aged women. During myomectomy for women who want to preserve fertility, it is advisable to detect and remove all myomas to decrease the risk of additional surgery. However, finding myomas during surgery is often challenging, especially for deep-seated myomas. Therefore, three-dimensional (3D) preoperative localization of myomas can be helpful for the surgical planning for myomectomy. However, the previously reported manual 3D segmenting method takes too much time and effort for clinical use. The objective of this study was to propose a new method of rapid 3D visualization of uterine myoma using a uterine template. Methods Magnetic resonance images were listed according to the slide spacing on each plane of the multiplanar reconstruction, and images that were determined to be myomas were selected by simply scrolling the mouse down. By using the selected images, a 3D grid with a slide spacing interval was constructed and filled on its plane and finally registered to a uterine template. Results The location of multiple myomas in the uterus was visualized in 3D and this proposed method is over 95% faster than the existing manual-segmentation method. Not only the size and location of the myomas, but also the shortest distance between the uterine surface and the myomas, can be calculated. This technique also enables the surgeon to know the number of total, removed, and remaining myomas on the 3D image. Conclusion This proposed 3D reconstruction method with a uterine template enables faster 3D visualization of myomas. PMID:29215821

Three-dimensional workstation is useful for measuring the correct size of abdominal aortic aneurysm diameters.

PubMed

Ihara, Tsutomu; Komori, Kimihiro; Yamamoto, Kiyohito; Kobayashi, Masayoshi; Banno, Hiroshi; Kodama, Akio

2013-02-01

Abdominal aortic aneurysm diameter is usually measured by the maximum minor-axis diameter on axial computed tomography (CT). However, this "traditional" diameter may underestimate the real size, as the aorta is not always straight and the aneurysm shape is sometimes in the form of an ellipse along the cross section. Therefore, we measured maximum major-axis diameters using a three-dimensional (3D) workstation and compared them with the traditional maximum minor-axis diameters measured using thin-slice axial CT. CT data of 141 AAA patients (with fusiform aneurysms) were stored in a 3D workstation. These thin-slice CT images were reviewed on the 3D workstation to obtain curved multiplanar reconstruction images (CPR images). Using the CPR images, we measured the maximum major-axis and minor-axis diameters on CPR and the angle of the aneurysms to the body axis. The mean traditional maximum minor-axis diameter was 51.2 ± 8.2 mm, whereas the mean maximum major-axis diameter on CPR was 54.7 ± 10.1 mm. Sixty eight patients had a mean aneurysm size of <50 mm when measured by the traditional minor-axis diameter. Among these patients, five (7.4%) had a major-axis diameter >55 mm on CPR. The measurement of the traditional maximum minor-axis diameter of aneurysms is useful in the case of most patients. However, the traditional maximum minor-axis diameter may underestimate the real aneurysmal diameter, particularly in patients with an ellipse-shaped aneurysm. The maximum major-axis diameter as measured using CPR images is effective for representing the real aneurysmal size. Copyright © 2013 Elsevier Inc. All rights reserved.

Cone-Beam Computed Tomography (CBCT) Hepatic Arteriography in Chemoembolization for Hepatocellular Carcinoma: Performance Depicting Tumors and Tumor Feeders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, In Joon; Chung, Jin Wook, E-mail: chungjw@snu.ac.kr; Yin, Yong Hu

2015-10-15

PurposeThis study was designed to analyze retrospectively the performance of cone-beam computed tomography (CBCT) hepatic arteriography in depicting tumors and their feeders and to investigate the related determining factors in chemoembolization for hepatocellular carcinoma (HCC).MethodsEighty-six patients with 142 tumors satisfying the imaging diagnosis criteria of HCC were included in this study. The performance of CBCT hepatic arteriography for chemoembolization per tumor and per patient was evaluated using maximum intensity projection images alone (MIP analysis) or MIP combined with multiplanar reformation images (MIP + MPR analysis) regarding the following three aspects: tumor depiction, confidence of tumor feeder detection, and trackability of tumor feeders.more » Tumor size, tumor enhancement, tumor location, number of feeders, diaphragmatic motion, portal vein enhancement, and hepatic artery to parenchyma enhancement ratio were regarded as potential determining factors.ResultsTumors were depicted in 125 (88.0 %) and 142 tumors (100 %) on MIP and MIP + MPR analysis, respectively. Imaging performances on MIP and MIP + MPR analysis were good enough to perform subsegmental chemoembolization without additional angiographic investigation in 88 (62.0 %) and 128 tumors (90.1 %) on per-tumor basis and in 43 (50 %) and 73 (84.9 %) on per-patient basis, respectively. Significant determining factors for performance in MIP + MPR analysis on per tumor basis were tumor size (p = 0.030), tumor enhancement (0.005), tumor location (p = 0.001), and diaphragmatic motion (p < 0.001).ConclusionsCBCT hepatic arteriography provided sufficient information for subsegmental chemoembolization by depicting tumors and their feeders in the vast majority of patients. Combined analysis of MIP and MPR images was essential to enhance the performance of CBCT hepatic arteriography.« less

Diffusion Tensor Imaging of Lumbar Nerve Roots: Comparison Between Fast Readout-Segmented and Selective-Excitation Acquisitions.

PubMed

Manoliu, Andrei; Ho, Michael; Nanz, Daniel; Piccirelli, Marco; Dappa, Evelyn; Klarhöfer, Markus; Del Grande, Filippo; Kuhn, Felix Pierre

2016-08-01

The aim of this study was to compare the quality of recently emerged advanced diffusion tensor imaging (DTI) techniques with conventional single-shot echo-planar imaging (EPI) in a functional assessment of lumbar nerve roots. The institutional review board approved the study including 12 healthy volunteers. Diffusion tensor imaging was performed at 3 T (MAGNETOM Skyra; Siemens Healthcare) with b-values of 0 and 700 s/mm and an isotropic spatial resolution for subsequent multiplanar reformatting. The nerve roots L2 to S1 were imaged in coronal orientation with readout-segmented EPI (rs-DTI) and selective-excitation EPI (sTX-DTI) with an acquisition time of 5 minutes each, and in axial orientation with single-shot EPI (ss-DTI) with an acquisition time of 12 minutes (scan parameters as in recent literature). Two independent readers qualitatively and quantitatively assessed image quality. The interobserver reliability ranged from "substantial" to "almost perfect" for all examined parameter and all 3 sequences (κ = 0.70-0.94). Overall image quality was rated higher, and artifact levels were scored lower for rs-DTI and sTX-DTI than for ss-DTI (P = 0.007-0.027), while fractional anisotropy and signal-to-noise ratio values were similar for all sequences (P ≥ 0.306 and P ≥ 0.100, respectively). Contrast-to-noise ratios were significantly higher for rs-DTI and ss-DTI than for sTX-DTI (P = 0.004-0.013). Despite shorter acquisition times, rs-DTI and sTX-DTI produced images of higher quality with smaller geometrical distortions than the current standard of reference, ss-DTI. Thus, DTI acquisitions in the coronal plane, requiring fewer slices for full coverage of exiting nerve roots, may allow for functional neurography in scan times suitable for routine clinical practice.

Automated detection of masses on whole breast volume ultrasound scanner: false positive reduction using deep convolutional neural network

NASA Astrophysics Data System (ADS)

Hiramatsu, Yuya; Muramatsu, Chisako; Kobayashi, Hironobu; Hara, Takeshi; Fujita, Hiroshi

2017-03-01

Breast cancer screening with mammography and ultrasonography is expected to improve sensitivity compared with mammography alone, especially for women with dense breast. An automated breast volume scanner (ABVS) provides the operator-independent whole breast data which facilitate double reading and comparison with past exams, contralateral breast, and multimodality images. However, large volumetric data in screening practice increase radiologists' workload. Therefore, our goal is to develop a computer-aided detection scheme of breast masses in ABVS data for assisting radiologists' diagnosis and comparison with mammographic findings. In this study, false positive (FP) reduction scheme using deep convolutional neural network (DCNN) was investigated. For training DCNN, true positive and FP samples were obtained from the result of our initial mass detection scheme using the vector convergence filter. Regions of interest including the detected regions were extracted from the multiplanar reconstraction slices. We investigated methods to select effective FP samples for training the DCNN. Based on the free response receiver operating characteristic analysis, simple random sampling from the entire candidates was most effective in this study. Using DCNN, the number of FPs could be reduced by 60%, while retaining 90% of true masses. The result indicates the potential usefulness of DCNN for FP reduction in automated mass detection on ABVS images.

Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

PubMed Central

Tsili, Athina C; Argyropoulou, Maria I

2015-01-01

Renal cell carcinoma (RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography (CT) is considered the examination of choice for the detection and staging of RCC. Multidetector CT (MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and three-dimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment. PMID:26120380

Displacement of a Broken Dental Injection Needle Into the Perivertebral Space.

PubMed

Sahin, Bayram; Yildirimturk, Senem; Sirin, Yigit; Basaran, Bora

2017-07-01

Dental injection needle breakage is an uncommon problem in dental practice. Displacement of the broken fragment into anatomical spaces is, on the other hand, a serious complication that occurs most commonly during inferior alveolar nerve blocks as a result of material wear, incorrect application of the anesthesia technique, or sudden movement of the patient during injection. Further complications such as infection, trismus, and nerve paralysis may exacerbate the condition and, if not treated adequately, life-threatening conditions may develop over time as the fragment dislodges deeper in soft tissues. Clinical symptoms of the patient, as well as the findings gathered from detailed physical examination and radiographic evaluation, are important factors to consider before performing an exploratory surgery. Removal of a broken needle may be troublesome due to its proximity to vital anatomic structures. Multislice computed tomography is a reliable imaging modality that provides accurate information to pinpoint the exact location of the needle fragment.This report describes a case of needle breakage occurred during inferior alveolar nerve block which was performed to extract a third molar tooth and the migration of the broken fragment from the right mandibular ramus area into the perivertebral space, with special emphasis on the surgical retrieval technique with multiplanar computed tomography imaging guidance.

Visualisation of the temporary cavity by computed tomography using contrast material.

PubMed

Schyma, Christian; Hagemeier, Lars; Greschus, Susanne; Schild, Hans; Madea, Burkhard

2012-01-01

The temporary cavity of a missile produces radial tears in ordnance gelatine, which correlate to the energy transfer. Computed tomography is a useful and non-destructive method to examine gelatine blocks. However, the tears give only few radiocontrast by air filling, which decreases with the time past shooting. Therefore, systematically, a radiocontrast material was searched to enhance the contrast. Different contrast materials were amalgamated to acryl paint, and about 7 g was sealed in a foil bag, which was integrated in the front of a standard 10% gelatine cylinder. Shots with Action-5 expanding bullets were performed from a 5-m distance. Gelatine was scanned by multi-slice computed tomography. The multiplanar reconstructed images were compared to mechanically cut slices of 1 cm thickness. It was shown experimentally that iodine containing water-soluble contrast material did not give sufficient contrast and caused diffusion artefacts. Best results were obtained by barium sulphate emulsion. The amount of acryl paint was sufficient to colour the tears for optical scanning. The radiocontrast of barium leads to satisfying imaging of tears and allowed the creation of a three-dimensional reconstruction of the temporary cavity. Comparison of optical and radiological results showed an excellent correlation, but absolute measures in computed tomographic (CT) images remained lower compared with optically gathered values in the gelatine slices. Combination of paint and contrast material for CT examination will facilitate the evaluation of complex ballistic models and increase accuracy.

Feasibility of self-gated isotropic radial late-phase MR imaging of the liver.

PubMed

Weiss, Jakob; Taron, Jana; Othman, Ahmed E; Grimm, Robert; Kuendel, Matthias; Martirosian, Petros; Ruff, Christer; Schraml, Christina; Nikolaou, Konstantin; Notohamiprodjo, Mike

2017-03-01

To evaluate feasibility of a 3D-isotropic self-gated radial volumetric interpolated breath-hold examination (VIBE) for late-phase MRI of the liver. 70 patients were included and underwent liver MRI at 1.5 T. Depending on the diagnosis, either Gd-EOB-DTPA (35 patients) or gadobutrol (35 patients) were administered. During late (gadobutrol) or hepatocyte-specific phase (Gd-EOB-DTPA), a radial prototype sequence was acquired and reconstructed using (1) self-gating with 40 % acceptance (rVIBE 40 ); (2) with 100 % acceptance of the data (rVIBE 100 ) and compared to Cartesian VIBE (cVIBE). Images were assessed qualitatively (image quality, lesion conspicuity, artefacts; 5-point Likert-scale: 5 = excellent; two independent readers) and quantitatively (coefficient-of-variation (CV); contrast-ratio) in axial and coronal reformations. In eight cases only rVIBE provided diagnostic image quality. Image quality of rVIBE 40 was rated significantly superior (p < 0.05) in Gd-EOB-DTPA-enhanced and coronal reformatted examinations as compared to cVIBE. Lesion conspicuity was significantly improved (p < 0.05) in coronal reformatted Gd-EOB-DTPA-enhanced rVIBE 40 in comparison to cVIBE. CV was higher in rVIBE 40 as compared to rVIBE 100 /cVIBE (p < 0.01). Gadobutrol-enhanced rVIBE 40 and cVIBE showed higher contrast-ratios than rVIBE 100 (p < 0.001), whereas no differences were found in Gd-EOB-DTPA-enhanced examinations. Self-gated 3D-isotropic rVIBE provides significantly superior image quality compared to cVIBE, especially in multiplanar reformatted and Gd-EOB-DTPA-enhanced examinations. • Radial VIBE acquisition reduces motion artefacts. • Gd-EOB-DTPA-enhanced scans provide improved image quality. • Non-diagnostic liver MRI examinations may be reduced by radial k-spaces sampling.

Three-dimensional vs. two-dimensional shear-wave elastography of the testes - preliminary study on a healthy collective.

PubMed

Marcon, J; Trottmann, M; Rübenthaler, J; D'Anastasi, M; Stief, C G; Reiser, M F; Clevert, D A

2016-01-01

Shear wave elastography (SWE) and its derivative Supersonic Shear Imaging (SSI) are newer techniques for the determination of tissue elasticity by measuring the velocity of generated shear waves (SWV), which correlates positively with tissue stiffness.The techniques are integrated into many modern ultrasound systems and have been examined in the evaluation of viscoelastic properties of different organ systems. Two-dimensional shear wave elastography (2D SWE) of the testes has been found to be a useful tool in recent studies which included the determination of standard values in healthy volunteers. Three-dimensional shear wave elastography (3D SWE) is the latest development in elastography and is made possible by generation of a multiplanar three-dimensional map via volumetric acquisition with a special ultrasound transducer. This technique allows the assessment of tissue elasticity in a three-dimensional, fully accessible organ map.The aim of this preliminary study was to both evaluate the feasibility of 3D SWE and to compare 2D and 3D SWE standard values in the testes of healthy subjects. We examined the testes of healthy male volunteers (n = 32) with a mean age of 51.06±17.75 years (range 25-77 years) by B-mode ultrasound, 2D and 3D SWE techniques in September of 2016. Volunteers with a history of testicular pathologies were excluded. For all imaging procedures the SL15-4 linear transducer (bandwidth 4-15 MHz) as well as the SLV16-4 volumetric probe (bandwidth 4-16 MHz) of the Aixplorer® ultrasound device (SuperSonic Imagine, Aix-en-Provence, France) were used. Seven regions of interest (ROI, Q-Box®) within the testes were evaluated for SWV using both procedures. SWV values were described in m/s. Results were statistically evaluated using univariateanalysis. Mean SWV values were 1.05 m/s for the 2D SWE and 1.12 m/s for the 3D SWE.Comparisons of local areas delivered no statistically significant differences (p = 0.11 to p = 0.66), except for the region in the central portion in the superior part of the coronal plane (p = 0.03). Testicular volume was significanty higher by a mean of 1.72 ml when measured with 3D SWE (p = 0.001). 3D SWE proved to be a feasible diagnostic tool in the assessment of testicular tissue, providing the examiner with a fully accessible three-dimensional map in a multiplanar or multislice view. With this technique a more precise testicular imaging - especially if combined with the display of tissue stiffness in SWE - is available and therefore could improve the diagnostic work-up of scrotal masses or the routine investigation of infertile men. Further studies for a better understanding in the context of various testicular pathologies will be required.

Facility Name | Research Site Name | NREL

Science.gov Websites

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Background: Preflight Screening, In-flight Capabilities, and Postflight Testing

NASA Technical Reports Server (NTRS)

Gibson, Charles Robert; Duncan, James

2009-01-01

Recommendations for minimal in-flight capabilities: Retinal Imaging - provide in-flight capability for the visual monitoring of ocular health (specifically, imaging of the retina and optic nerve head) with the capability of downlinking video/still images. Tonometry - provide more accurate and reliable in-flight capability for measuring intraocular pressure. Ultrasound - explore capabilities of current on-board system for monitoring ocular health. We currently have limited in-flight capabilities on board the International Space Station for performing an internal ocular health assessment. Visual Acuity, Direct Ophthalmoscope, Ultrasound, Tonometry(Tonopen):

Computer-assisted oblique single-cut rotation osteotomy to reduce a multidirectional tibia deformity: case report.

PubMed

Dobbe, J G G; du Pré, K J; Blankevoort, L; Streekstra, G J; Kloen, P

2017-08-01

The correction of multiplanar deformity is challenging. We describe preoperative 3-D planning and treatment of a complex tibia malunion using an oblique single-cut rotation osteotomy to correct deformity parameters in the sagittal, coronal and transverse plane. At 5 years postoperatively, the patient ambulates without pain with a well-aligned leg.

Roles of universal three-dimensional image analysis devices that assist surgical operations.

PubMed

Sakamoto, Tsuyoshi

2014-04-01

The circumstances surrounding medical image analysis have undergone rapid evolution. In such a situation, it can be said that "imaging" obtained through medical imaging modality and the "analysis" that we employ have become amalgamated. Recently, we feel the distance between "imaging" and "analysis" has become closer regarding the imaging analysis of any organ system, as if both terms mentioned above have become integrated. The history of medical image analysis started with the appearance of the computer. The invention of multi-planar reconstruction (MPR) used in the helical scan had a significant impact and became the basis for recent image analysis. Subsequently, curbed MPR (CPR) and other methods were developed, and the 3D diagnostic imaging and image analysis of the human body have started on a full scale. Volume rendering: the development of a new rendering algorithm and the significant improvement of memory and CPUs contributed to the development of "volume rendering," which allows 3D views with retained internal information. A new value was created by this development; computed tomography (CT) images that used to be for "diagnosis" before that time have become "applicable to treatment." In the past, before the development of volume rendering, a clinician had to mentally reconstruct an image reconfigured for diagnosis into a 3D image, but these developments have allowed the depiction of a 3D image on a monitor. Current technology: Currently, in Japan, the estimation of the liver volume and the perfusion area of the portal vein and hepatic vein are vigorously being adopted during preoperative planning for hepatectomy. Such a circumstance seems to be brought by the substantial improvement of said basic techniques and by upgrading the user interface, allowing doctors easy manipulation by themselves. The following describes the specific techniques. Future of post-processing technology: It is expected, in terms of the role of image analysis, for better or worse, that computer-aided diagnosis (CAD) will develop to a highly advanced level in every diagnostic field. Further, it is also expected in the treatment field that a technique coordinating various devices will be strongly required as a surgery navigator. Actually, surgery using an image navigator is being widely studied, and coordination with hardware, including robots, will also be developed. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

New Insight from Using Spatiotemporal Image Correlation in Prenatal Screening of Fetal Conotruncal Defects

PubMed Central

Xie, Zuo-ping; Zhao, Bo-wen; Yuan, Hua; Hua, Qi-qi; Jin, She-hong; Shen, Xiao-yan; Han, Xin-hong; Zhou, Jia-mei; Fang, Min; Chen, Jin-hong

2013-01-01

Background: To establish the reference range of the angle between ascending aorta and main pulmonary artery of fetus in the second and third trimester using spatiotemporal image correlation (STIC), and to investigate the value of this angle in prenatal screening of conotruncal defects (CTDs). Materials and Methods: Volume images of 311 normal fetuses along with 20 fetuses with congenital heart diseases were recruited in this cross-sectional study. An offline analysis of acquired volume datasets was carried out with multiplanar mode. The angle between aorta and pulmonary artery was measured by navigating the pivot point and rotating axes and the reference range was established. The images of ascending aorta and main pulmonary artery in fetuses with congenital heart diseases were observed by rotating the axes within the normal angle reference range. Results: The angle between ascending aorta and main pulmonary artery of the normal fetus (range: 59.1˚~97.0˚, mean ± SD: 78.0˚ ± 9.7˚) was negatively correlated with gestational age (r = -0.52; p<0.01). By rotating the normal angle range corresponding to gestational age, the fetuses with CTD could not display views of their left ventricular long axis and main pulmonary trunk correctly. Conclusion: The left ventricular long axis and main pulmonary trunk views can be displayed using STIC so that the echocardiographic protocol of the cardiovascular joint could be standardized. The reference range of the angle between ascending aorta and main pulmonary artery is clinically useful in prenatal screening of CTD and provides a reliable quantitative standard to estimate the spatial relationship of the large arteries of fetus. PMID:24520485

Spine centerline extraction and efficient spine reading of MRI and CT data

NASA Astrophysics Data System (ADS)

Lorenz, C.; Vogt, N.; Börnert, P.; Brosch, T.

2018-03-01

Radiological assessment of the spine is performed regularly in the context of orthopedics, neurology, oncology, and trauma management. Due to the extension and curved geometry of the spinal column, reading is time-consuming and requires substantial user interaction to navigate through the data during inspection. In this paper a spine geometry guided viewing approach is proposed facilitating reading by reducing the degrees of freedom to be manipulated during inspection of the data. The method is using the spine centerline as a representation of the spine geometry. We assume that renderings most useful for reading are those that can be locally defined based on a rotation and translation relative to the spine centerline. The resulting renderings conserve locally the relation to the spine and lead to curved planar reformats that can be adjusted using a small set of parameters to minimize user interaction. The spine centerline is extracted by an automated image to image foveal fully convolutional neural network (FFCN) based approach. The network consists of three parallel convolutional pathways working on different levels of resolution and processed fields of view. The outputs of the parallel pathways are combined by a subsequent feature integration pathway to yield the (final) centerline probability map, which is converted into a set of spine centerline points. The network has been trained separately using two data set types, one comprising a mixture of T1 and T2 weighted spine MR images and one using CT image data. We achieve an average centerline position error of 1.7 mm for MR and 0.9 mm for CT and a DICE coefficient of 0.84 for MR and 0.95 for CT. Based on the thus obtained centerline viewing and multi-planar reformatting can be easily facilitated.

Three-dimensional virtual bronchoscopy using a tablet computer to guide real-time transbronchial needle aspiration.

PubMed

Fiorelli, Alfonso; Raucci, Antonio; Cascone, Roberto; Reginelli, Alfonso; Di Natale, Davide; Santoriello, Carlo; Capuozzo, Antonio; Grassi, Roberto; Serra, Nicola; Polverino, Mario; Santini, Mario

2017-04-01

We proposed a new virtual bronchoscopy tool to improve the accuracy of traditional transbronchial needle aspiration for mediastinal staging. Chest-computed tomographic images (1 mm thickness) were reconstructed with Osirix software to produce a virtual bronchoscopic simulation. The target adenopathy was identified by measuring its distance from the carina on multiplanar reconstruction images. The static images were uploaded in iMovie Software, which produced a virtual bronchoscopic movie from the images; the movie was then transferred to a tablet computer to provide real-time guidance during a biopsy. To test the validity of our tool, we divided all consecutive patients undergoing transbronchial needle aspiration retrospectively in two groups based on whether the biopsy was guided by virtual bronchoscopy (virtual bronchoscopy group) or not (traditional group). The intergroup diagnostic yields were statistically compared. Our analysis included 53 patients in the traditional and 53 in the virtual bronchoscopy group. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for the traditional group were 66.6%, 100%, 100%, 10.53% and 67.92%, respectively, and for the virtual bronchoscopy group were 84.31%, 100%, 100%, 20% and 84.91%, respectively. The sensitivity ( P  = 0.011) and diagnostic accuracy ( P  = 0.011) of sampling the paratracheal station were better for the virtual bronchoscopy group than for the traditional group; no significant differences were found for the subcarinal lymph node. Our tool is simple, economic and available in all centres. It guided in real time the needle insertion, thereby improving the accuracy of traditional transbronchial needle aspiration, especially when target lesions are located in a difficult site like the paratracheal station. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

The effect of sagittal rotation of the glenoid on axial glenoid width and glenoid version in computed tomography scan imaging.

PubMed

Gross, Daniel J; Golijanin, Petar; Dumont, Guillaume D; Parada, Stephen A; Vopat, Bryan G; Reinert, Steven E; Romeo, Anthony A; Provencher, C D R Matthew T

2016-01-01

Computed tomography (CT) scans of the shoulder are often not well aligned to the axis of the scapula and glenoid. The purpose of this paper was to determine the effect of sagittal rotation of the glenoid on axial measurements of anterior-posterior (AP) glenoid width and glenoid version attained by standard CT scan. In addition, we sought to define the angle of rotation required to correct the CT scan to optimal positioning. A total of 30 CT scans of the shoulder were reformatted using OsiriX software multiplanar reconstruction. The uncorrected (UNCORR) and corrected (CORR) CT scans were compared for measurements of both (1) axial AP glenoid width and (2) glenoid version at 5 standardized axial cuts. The mean difference in glenoid version was 2.6% (2° ± 0.1°; P = .0222) and the mean difference in AP glenoid width was 5.2% (1.2 ± 0.42 mm; P = .0026) in comparing the CORR and UNCORR scans. The mean angle of correction required to align the sagittal plane was 20.1° of rotation (range, 9°-39°; standard error of mean, 1.2°). These findings demonstrate that UNCORR CT scans of the glenohumeral joint do not correct for the sagittal rotation of the glenoid, and this affects the characteristics of the axial images. Failure to align the sagittal image to the 12-o'clock to 6-o'clock axis results in measurement error in both glenoid version and AP glenoid width. Use of UNCORR CT images may have notable implications for decision-making and surgical treatment. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

COMPARISONS AMONG RADIOGRAPHY, ULTRASONOGRAPHY AND COMPUTED TOMOGRAPHY FOR EX VIVO CHARACTERIZATION OF STIFLE OSTEOARTHRITIS IN THE HORSE.

PubMed

De Lasalle, Julie; Alexander, Kate; Olive, Julien; Laverty, Sheila

2016-09-01

A better understanding of imaging characteristics of equine stifle osteoarthritis (OA) may allow earlier detection and improve prognosis. Objectives of this ex vivo, prospective, methods comparison study were to (1) describe the location and severity of naturally acquired OA lesions in the equine stifle using ultrasound (US), radiography (XR), computed tomography (CT), and macroscopic evaluation (ME); (2) compare the diagnostic performance of each imaging modality with ME; and (3) describe subchondral bone mineral density (BMD) in equine stifle joints with OA using CT. Radiographic, CT, and US evaluations were performed on 23 equine cadaver stifles and compared with ME. Significant associations were found between osteophyte global scores for all imaging modalities (CT, P ˂ 0.0001; XR, P = 0.005; US, P = 0.04) vs. ME osteophyte global scores. Osteophytes were detected most frequently in the medial femorotibial (MFT) joint. A specific pattern of osteophytes was observed, with a long ridge of new bone at the insertion of the MFT joint capsule cranially on the medial femoral condyle. A novel caudo-10°proximo-5°lateral-cranio-disto-medial oblique radiographic projection was helpful for detection of intercondylar osteophytes. Multiplanar CT reformatted images were helpful for characterizing all osteophytes. Osteophyte grades at most sites did not differ among modalities. Low sensitivity/specificity for subchondral bone sclerosis and flattening of femoral condyles suggested that these signs may not be reliable radiographic and CT indicators of equine stifle OA. Equine stifle OA was associated with a decrease in BMD and specific sites of focal subchondral bone resorption/cyst formation were found in some specimens. © 2016 American College of Veterinary Radiology.

Intra- and Interobserver Variability of Cochlear Length Measurements in Clinical CT.

PubMed

Iyaniwura, John E; Elfarnawany, Mai; Riyahi-Alam, Sadegh; Sharma, Manas; Kassam, Zahra; Bureau, Yves; Parnes, Lorne S; Ladak, Hanif M; Agrawal, Sumit K

2017-07-01

The cochlear A-value measurement exhibits significant inter- and intraobserver variability, and its accuracy is dependent on the visualization method in clinical computed tomography (CT) images of the cochlea. An accurate estimate of the cochlear duct length (CDL) can be used to determine electrode choice, and frequency map the cochlea based on the Greenwood equation. Studies have described estimating the CDL using a single A-value measurement, however the observer variability has not been assessed. Clinical and micro-CT images of 20 cadaveric cochleae were acquired. Four specialists measured A-values on clinical CT images using both standard views and multiplanar reconstructed (MPR) views. Measurements were repeated to assess for intraobserver variability. Observer variabilities were evaluated using intra-class correlation and absolute differences. Accuracy was evaluated by comparison to the gold standard micro-CT images of the same specimens. Interobserver variability was good (average absolute difference: 0.77 ± 0.42 mm) using standard views and fair (average absolute difference: 0.90 ± 0.31 mm) using MPR views. Intraobserver variability had an average absolute difference of 0.31 ± 0.09 mm for the standard views and 0.38 ± 0.17 mm for the MPR views. MPR view measurements were more accurate than standard views, with average relative errors of 9.5 and 14.5%, respectively. There was significant observer variability in A-value measurements using both the standard and MPR views. Creating the MPR views increased variability between experts, however MPR views yielded more accurate results. Automated A-value measurement algorithms may help to reduce variability and increase accuracy in the future.

Flat-detector computed tomography evaluation in an experimental animal aneurysm model after endovascular treatment: A pilot study.

PubMed

Ott, Sabine; Gölitz, Philipp; Adamek, Edyta; Royalty, Kevin; Doerfler, Arnd; Struffert, Tobias

2015-08-01

We compared flat-detector computed tomography angiography (FD-CTA) to multislice computed tomography (MS-CTA) and digital subtracted angiography (DSA) for the visualization of experimental aneurysms treated with stents, coils or a combination of both.In 20 rabbits, aneurysms were created using the rabbit elastase aneurysm model. Seven aneurysms were treated with coils, seven with coils and stents, and six with self-expandable stents alone. Imaging was performed by DSA, MS-CTA and FD-CTA immediately after treatment. Multiplanar reconstruction (MPR) was performed and two experienced reviewers compared aneurysm/coil package size, aneurysm occlusion, stent diameters and artifacts for each modality.In aneurysms treated with stents alone, the visualization of the aneurysms was identical in all three imaging modalities. Residual aneurysm perfusion was present in two cases and visible in DSA and FD-CTA but not in MS-CTA. The diameter of coil-packages was overestimated in MS-CT by 56% and only by 16% in FD-CTA compared to DSA (p < 0.05). The diameter of stents was identical for DSA and FD-CTA and was significantly overestimated in MS-CTA (p < 0.05). Beam/metal hardening artifacts impaired image quality more severely in MS-CTA compared to FD-CTA.MS-CTA is impaired by blooming and beam/metal hardening artifacts in the visualization of implanted devices. There was no significant difference between measurements made with noninvasive FD-CTA compared to gold standard of DSA after stenting and after coiling/stent-assisted coiling of aneurysms. FD-CTA may be considered as a non-invasive alternative to the gold standard 2D DSA in selected patients that require follow up imaging after stenting. © The Author(s) 2015.

The prevalence of transpancreatic common hepatic artery and coexisting variant anatomy.

PubMed

Ishigami, Kousei; Nishie, Akihiro; Asayama, Yoshiki; Ushijima, Yasuhiro; Takayama, Yukihisa; Okamoto, Daisuke; Fujita, Nobuhiro; Yoshizumi, Tomoharu; Harimoto, Norifumi; Ohtsuka, Takao; Nakata, Kohei; Honda, Hiroshi

2018-05-01

We studied the prevalence of the transpancreatic common hepatic artery (tp-CHA) and coexisting variant anatomy. The study group comprised 788 consecutive liver transplant donor candidates who had undergone thin-section multidetector-row computed tomography (MDCT) studies to investigate vascular anatomy. Multiplanar reformatted (MPR) images obtained from the arterial phase were retrospectively reviewed to assess the presence/absence of the tp-CHA. Five cases of tp-CHA with pancreaticobiliary tumors were also included in an investigation of the presence/absence of variant hepatic arteries, celiac stenosis, and circumportal pancreas. Three of the 788 (0.38%) donor candidates had a tp-CHA. Overall, eight tp-CHA cases were assessed for coexisting variant anatomy. Seven of these eight cases had a hepatomesenteric trunk, six had celiac stenosis, and two had a circumportal pancreas. The prevalence of the tp-CHA was 0.38% (approx. one in 260 in normal populations). A tp-CHA can commonly be associated with a hepatomesenteric trunk and celiac stenosis. A circumportal pancreas can also coexist with a tp-CHA. Clin. Anat. 31:598-604, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

[Chronic pancreatitis: which is the role of 320-row CT for the staging?].

PubMed

Stabile Ianora, Amato Antonio; Rubini, Giuseppe; Lorusso, Filomenamila; Ambriola, Angela; Rella, Leonarda; Di Crescenzo, Vincenzo; Moschetta, Marco

2013-01-01

The purpose of this study was to evaluate the diagnostic potential of multi-planar and volumetric reconstructions obtained from isotropic data by using 16-slice computed tomography (CT) in the diagnosis and staging of chronic pancreatitis. In a group of 42 patients CT images were evaluated searching for alterations in morphology and structure of the pancreas, alterations of the Wirsung duct, dilatation of the bile ducts, fluid collections, and vascular involvement of the digestive tract. The disease was then staged in mild, moderate and severe and correlated with the clinical staging. CT allowed the recognition of chronic pancreatitis in all cases. The staging was correct in 25/42 patients, with an accuracy rate of 59.5%. In the staging of moderate and severe forms, CT correlation with clinical and laboratory data was valid, but in mild forms it appeared less significant. Multi-detector CT is accurate in the recognition of moderate, advanced forms of chronic pancreatitis and in the identification of its complications, while it is poorly correlated with the clinical staging in mild forms of the disease.

Development of preoperative planning software for transforaminal endoscopic surgery and the guidance for clinical applications.

PubMed

Chen, Xiaojun; Cheng, Jun; Gu, Xin; Sun, Yi; Politis, Constantinus

2016-04-01

Preoperative planning is of great importance for transforaminal endoscopic techniques applied in percutaneous endoscopic lumbar discectomy. In this study, a modular preoperative planning software for transforaminal endoscopic surgery was developed and demonstrated. The path searching method is based on collision detection, and the oriented bounding box was constructed for the anatomical models. Then, image reformatting algorithms were developed for multiplanar reconstruction which provides detailed anatomical information surrounding the virtual planned path. Finally, multithread technique was implemented to realize the steady-state condition of the software. A preoperative planning software for transforaminal endoscopic surgery (TE-Guider) was developed; seven cases of patients with symptomatic lumbar disc herniations were planned preoperatively using TE-Guider. The distances to the midlines and the direction of the optimal paths were exported, and each result was in line with the empirical value. TE-Guider provides an efficient and cost-effective way to search the ideal path and entry point for the puncture. However, more clinical cases will be conducted to demonstrate its feasibility and reliability.

A comparative study of the skeletal morphology of the temporo-mandibular joint of children and adults.

PubMed

Meng, F; Liu, Y; Hu, K; Zhao, Y; Kong, L; Zhou, S

2008-01-01

The skeletal morphology of the temporo-mandibular joint (TMJ) is constantly remodeled. A comparative study was undertaken to determine and characterize the differences in the skeletal morphology of TMJ of children and adults. The study was conducted on 30 children cadavers and 30 adult volunteers. Parameters that could reflect TMJ skeletal morphology were measured with a new technology combining helical computed tomography (CT) scan with multi-planar reformation (MPR) imaging. Significant differences between children cadavers and adults were found in the following parameters (P<0.05): Condylar axis inclination, smallest area of condylar neck/largest area of condylar process, inclination of anterior slope in inner, middle, and outer one-third of condyle, anteroposterior/mediolateral dimension of condyle, length of anterior slope/posterior slope in inner and middle one-third of condyle, anteroposterior dimension of condyle/glenoid fossa, mediolateral dimension of condyle/glenoid fossa, inclination of anterior slope of glenoid fossa, depth of glenoid fossa, and anteroposterior/mediolateral dimension of glenoid fossa. There are significant differences of TMJ skeletal morphology between children and adults.

Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis.

PubMed

Holly, Brian P; Steenburg, Scott D

2011-01-01

Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.

Morphology and function: MR pineal volume and melatonin level in human saliva are correlated.

PubMed

Liebrich, Luisa-Sophie; Schredl, Michael; Findeisen, Peter; Groden, Christoph; Bumb, Jan Malte; Nölte, Ingo S

2014-10-01

To investigate the relation between circadian saliva melatonin levels and pineal volume as determined by MRI. Plasma melatonin levels follow a circadian rhythm with a high interindividual variability. In 103 healthy individuals saliva melatonin levels were determined at four time points within 24 h and MRI was performed once (3.0 Tesla, including three-dimensional T2 turbo spin echo [3D-T2-TSE], susceptibility-weighted imaging [SWI]). Pineal volume as well as cyst volume were assessed from multiplanar reconstructed 3D-T2-TSE images. Pineal calcification volume tissue was determined on SWI. To correct for hormonal inactive pineal tissue, cystic and calcified areas were excluded. Sleep quality was assessed with the Landeck Inventory for sleep quality disturbance. Solid and uncalcified pineal volume correlated to melatonin maximum (r = 0.28; P < 0.05) and area under the curve (r = 0.29; P < 0.05). Of interest, solid and uncalcified pineal volume correlated negatively with the sleep rhythm disturbances subscore (r = -0.17; P < 0.05) despite a very homogenous population. Uncalcified solid pineal tissue measured by 3D-T2-TSE and SWI is related to human saliva melatonin levels. The analysis of the sleep quality and pineal volume suggests a linkage between better sleep quality and hormonal active pineal tissue. © 2013 Wiley Periodicals, Inc.

Detection and visualization of endoleaks in CT data for monitoring of thoracic and abdominal aortic aneurysm stents

NASA Astrophysics Data System (ADS)

Lu, J.; Egger, J.; Wimmer, A.; Großkopf, S.; Freisleben, B.

2008-03-01

In this paper we present an efficient algorithm for the segmentation of the inner and outer boundary of thoratic and abdominal aortic aneurysms (TAA & AAA) in computed tomography angiography (CTA) acquisitions. The aneurysm segmentation includes two steps: first, the inner boundary is segmented based on a grey level model with two thresholds; then, an adapted active contour model approach is applied to the more complicated outer boundary segmentation, with its initialization based on the available inner boundary segmentation. An opacity image, which aims at enhancing important features while reducing spurious structures, is calculated from the CTA images and employed to guide the deformation of the model. In addition, the active contour model is extended by a constraint force that prevents intersections of the inner and outer boundary and keeps the outer boundary at a distance, given by the thrombus thickness, to the inner boundary. Based upon the segmentation results, we can measure the aneurysm size at each centerline point on the centerline orthogonal multiplanar reformatting (MPR) plane. Furthermore, a 3D TAA or AAA model is reconstructed from the set of segmented contours, and the presence of endoleaks is detected and highlighted. The implemented method has been evaluated on nine clinical CTA data sets with variations in anatomy and location of the pathology and has shown promising results.

An analysis of malar fat volume in two age groups: implications for craniofacial surgery.

PubMed

Corey, Christina L; Popelka, Gerald R; Barrera, Jose E; Most, Sam P

2012-12-01

Objective To evaluate how malar fat pad (MFP) volumes vary with age, after controlling for gender and body mass index (BMI). Study Design A prospective case-control study evaluating volume of the MFP in women of two age groups. Methods Soft tissue dimensions were measured in eight subjects using magnetic resonance imaging. A multiplanar localizing sequence, followed in sagittal and coronal orientations using a turbo spin echo sequence, was performed to define the MFP. Volumetric calculations were then performed using a 3D image analysis application (Dextroscope, Volume Interactions, Republic of Singapore) to circumscribe areas, orient dimensions, and calculate volumes of the MFP. Results These data reveal no significant difference in the mean (standard deviation) right MFP (p = 0.50), left MFP (p = 0.41), or total MFP (p = 0.45) volumes when comparing the two age groups. In addition, these data indicate that there was no correlation between age and total MFP volume (Pearson correlation coefficient 0.27). Moreover, there was no correlation between age and the ratio of total volume/BMI (Pearson correlation coefficient -0.18). Conclusions Although the sample size of this study was small, these data indicate that ptosis of midfacial fat is more important than volume loss in midfacial aging. These data would suggest repositioning as the primary modality for craniofacial reconstruction.

Contribution of cone beam computed tomography to the detection of apical root resorption after orthodontic treatment in root-filled and vital teeth.

PubMed

Castro, Iury; Valladares-Neto, José; Estrela, Carlos

2015-09-01

To investigate whether root-filled teeth are similar to vital pulp teeth in terms of apical root resorption (ARR) after orthodontic treatment. An original sample of cone beam computed tomography (CBCT) images of 1256 roots from 30 orthodontic patients were analyzed. The inclusion criteria demanded root-filled teeth and their contralateral vital teeth, while teeth with history of trauma had to be excluded to comply with exclusion criteria. CBCT images of root-filled teeth were compared before and after orthodontic treatment in a split-mouth design study. Tooth measurements were made with multiplanar reconstruction using axial-guided navigation. The statistical difference between the treatment effects was compared using the paired t-test. Twenty posterior root-filled teeth and their contralaterals with vital pulp were selected before orthodontic treatment from six adolescents (two boys and four girls; mean [SD] age 12.8 [1.8] years). No differences were detected between filled and vital root lengths before treatment (P  =  .4364). The mean differences in root length between preorthodontic and postorthodontic treatment in filled- and vital roots were -0.30 mm and -0.16 mm, respectively, without any statistical difference (P  =  .4197) between them. There appears to be no increase in ARR after orthodontic treatment in root-filled teeth with no earlier ARR.

Quantitative analyses of variability in normal vaginal shape and dimension on MR images

PubMed Central

Luo, Jiajia; Betschart, Cornelia; Ashton-Miller, James A.; DeLancey, John O. L.

2016-01-01

Introduction and hypothesis We present a technique for quantifying inter-individual variability in normal vaginal shape, axis, and dimension, and report findings in healthy women. Methods Eighty women (age: 28~70 years) with normal pelvic organ support underwent supine, multi-planar proton-density MRI. Vaginal width was assessed at five evenly-spaced locations, and vaginal axis, length, and surface area were quantified via ImageJ and MATLAB. Results The mid-sagittal plane angles, relative to the horizontal, of three vaginal axes were 90± 11, 72± 21, and 41± 22° (caudal to cranial, p < 0.001). The mean (± SD) vaginal widths were 17± 5, 24± 4, 30± 7, 41± 9, and 45± 12 mm at the five locations (caudal to cranial, p < 0.001). Mid-sagittal lengths for anterior and posterior vaginal walls were 63± 9 and 98 ± 18 mm respectively. The vaginal surface area was 72 ± 21 cm2 (range: 34 ~ 164 cm2). The coefficient of determination between any demographic variable and any vaginal dimension did not exceed 0.16. Conclusions Large variations in normal vaginal shape, axis, and dimensions were not explained by body size or other demographic variables. This variation has implications for reconstructive surgery, intravaginal and surgical product design, and vaginal drug delivery. PMID:26811115

Aircraft mishap investigation with radiology-assisted autopsy: helicopter crash with control injury.

PubMed

Folio, R Les; Harcke, H Theodore; Luzi, Scott A

2009-04-01

Radiology-assisted autopsy traditionally has been plain film-based, but now is being augmented by computed tomography (CT). The authors present a two-fatality rotary wing crash scenario illustrating application of advanced radiographic techniques that can guide and supplement the forensic pathologist's physical autopsy. The radiographic findings also have the potential for use by the aircraft mishap investigation board. Prior to forensic autopsy, the two crash fatalities were imaged with conventional two-dimensional radiographs (digital technique) and with multidetector CT The CT data were used for multiplanar two-dimensional and three-dimensional (3D) image reconstruction. The forensic pathologist was provided with information about skeletal fractures, metal fragment location, and other pathologic findings of potential use in the physical autopsy. The radiologic autopsy served as a supplement to the physical autopsy and did not replace the traditional autopsy in these cases. Both individuals sustained severe blunt force trauma with multiple fractures of the skull, face, chest, pelvis, and extremities. Individual fractures differed; however, one individual showed hand and lower extremity injuries similar to those associated with control of the aircraft at the time of impact. The concept of "control injury" has been challenged by Campman et al., who found that control surface injuries have a low sensitivity and specificity for establishing who the pilot was in an accident. The application of new post mortem imaging techniques may help to resolve control injury questions. In addition, the combination of injuries in our cases may contribute to further understanding of control surface injury patterns in helicopter mishaps.

Pineal gland volume in primary insomnia and healthy controls: a magnetic resonance imaging study.

PubMed

Bumb, Jan M; Schilling, Claudia; Enning, Frank; Haddad, Leila; Paul, Franc; Lederbogen, Florian; Deuschle, Michael; Schredl, Michael; Nolte, Ingo

2014-06-01

Little is known about the relation between pineal volume and insomnia. Melatonin promotes sleep processes and, administered as a drug, it is suitable to improve primary and secondary sleep disorders in humans. Recent magnetic resonance imaging studies suggest that human plasma and saliva melatonin levels are partially determined by the pineal gland volume. This study compares the pineal volume in a group of patients with primary insomnia to a group of healthy people without sleep disturbance. Pineal gland volume (PGV) was measured on the basis of high-resolution 3 Tesla MRI (T1-magnetization prepared rapid gradient echo) in 23 patients and 27 controls, matched for age, gender and educational status. Volume measurements were performed conventionally by manual delineation of the pineal borders in multi-planar reconstructed images. Pineal gland volume was significantly smaller (P < 0.001) in patients (48.9 ± 26.6 mm(3) ) than in controls (79 ± 30.2 mm(3) ). In patients PGV correlated negatively with age (r = -0.532; P = 0.026). Adjusting for the effect of age, PGV and rapid eye movement (REM) latency showed a significant positive correlation (rS  = 0.711, P < 0.001) in patients. Pineal volume appears to be reduced in patients with primary insomnia compared to healthy controls. Further studies are needed to clarify whether low pineal volume is the basis or the consequence of functional sleep changes to elucidate the molecular pathology for the pineal volume loss in primary insomnia. © 2014 European Sleep Research Society.

External root resorption of the second molar associated with mesially and horizontally impacted mandibular third molar: evidence from cone beam computed tomography.

PubMed

Wang, Dongmiao; He, Xiaotong; Wang, Yanling; Li, Zhongwu; Zhu, Yumin; Sun, Chao; Ye, Jinhai; Jiang, Hongbing; Cheng, Jie

2017-05-01

The aim of the present study was to assess the incidence and risk factors of ERR in second molars with mesially and horizontally impacted mandibular third molars using cone beam computed tomography (CBCT) images from patients in a Chinese tertiary referral hospital. A total number of 216 patients with 362 mesially and horizontally impacted mandibular third molars who were treated at our institution from 2014 to 2015 was retrospectively included. The ERR in second molars was identified on CBCT multiplanar images. The associations between incidence of ERR and multiple clinical parameters were statistically analyzed by Chi-square test. Moreover, the risk factors for ERR in second molars were further assessed by multivariate regression analysis. The overall incidence of ERR in second molars was 20.17 % (73/362) as detected on CBCT images. The presence of ERR significantly associated with patients age and impaction depth of mandibular third molars. However, no significant relationship was found between ERR severity and impaction depth or ERR location. Multivariate regression analyses further revealed age over 35 years and impaction depth as important risk factors affecting the ERR incidence caused by mesial and horizontal impaction of mandibular third molar. ERR in second molar resulted from mesially and horizontally impacted mandibular third molar is not very rare and can be reliably identified via CBCT scan. Given the possibility of ERR associated with third molar impaction, the prophylactic removal of these impacted teeth could be considered especially for those patients with over 35 years and mesially and horizontally impacted teeth.

Using the MDCT thick slab MinIP method for the follow-up of pulmonary emphysema.

PubMed

Lan, Hai; Nishitani, Hiromu; Nishihara, Sadamitsu; Ueno, Junji; Takao, Shoichiro; Iwamoto, Seiji; Kawanaka, Takashi; Mahmut, Mawlan; Qingge, Si

2011-08-01

The purpose of this study was to evaluate the usefulness of thick slab minimum intensity projection (MinIP) as a follow-up method in patients with pulmonary emphysema. This method was used to determine the presence or absence of changes over time in the lung field based on multi-detector-row CT (MDCT) data. Among patients diagnosed with pulmonary emphysema who underwent 16-MDCT (slice thickness, 1 mm) twice at an interval of 6 months or more, 12 patients without changes in the lung field and 14 with clear changes in the lung field were selected as subjects. An image interpretation experiment was performed by five image interpreters. Pulmonary emphysema was followed up using two types of thick slab MinIP (thick slab MinIP 1 and 2) and multi-planar reformation (MPR), and the results of image interpretation were evaluated by receiver operating characteristic (ROC) analysis. In addition, the time required for image interpretation was compared among the three follow-up methods. The area under the ROC curve (Az) was 0.794 for thick slab MinIP 1, 0.778 for the thick slab MinIP 2, and 0.759 for MPR, showing no significant differences among the three methods. Individual differences in each item were significantly more marked for MPR than for thick slab MinIP. The time required for image interpretation was around 18 seconds for thick slab MinIP 1, 11 seconds for thick slab MinIP 2, and approximately 127 seconds for MPR, showing significant differences among the three methods. There were no significant differences in the results of image interpretation regarding the presence or absence of changes in the lung fields between thick slab MinIP and MPR. However, thick slab MinIP showed a shorter image interpretation time and smaller individual differences in the results among image interpreters than MPR, suggesting the usefulness of this method for determining the presence or absence of changes with time in the lung fields of patients with pulmonary emphysema.

Ileocecocolic volvulus in a German shepherd dog

PubMed Central

Javard, Romain; Specchi, Swan; Benamou, Jérôme; Lapointe, Catherine; Deffontaines, Jean-Baptiste; Planté, Jérôme; d’Anjou, Marc-André

2014-01-01

This report describes an ileocecocolic volvulus in a German shepherd dog with risk factors of previous abdominal surgeries and concurrent chronic enteropathy. Contrast-enhanced computed tomography (CT) with multiplanar reformatting was more sensitive than abdominal radiographs or ultrasound to obtain a diagnosis, because of the presence of a “whirl-sign” on CT. A combination of colopexy and cecopexy was succesfully used to treat the patient’s condition. PMID:25392556

Quantitative micro-CT based coronary artery profiling using interactive local thresholding and cylindrical coordinates.

PubMed

Panetta, Daniele; Pelosi, Gualtiero; Viglione, Federica; Kusmic, Claudia; Terreni, Marianna; Belcari, Nicola; Guerra, Alberto Del; Athanasiou, Lambros; Exarchos, Themistoklis; Fotiadis, Dimitrios I; Filipovic, Nenad; Trivella, Maria Giovanna; Salvadori, Piero A; Parodi, Oberdan

2015-01-01

Micro-CT is an established imaging technique for high-resolution non-destructive assessment of vascular samples, which is gaining growing interest for investigations of atherosclerotic arteries both in humans and in animal models. However, there is still a lack in the definition of micro-CT image metrics suitable for comprehensive evaluation and quantification of features of interest in the field of experimental atherosclerosis (ATS). A novel approach to micro-CT image processing for profiling of coronary ATS is described, providing comprehensive visualization and quantification of contrast agent-free 3D high-resolution reconstruction of full-length artery walls. Accelerated coronary ATS has been induced by high fat cholesterol-enriched diet in swine and left coronary artery (LCA) harvested en bloc for micro-CT scanning and histologic processing. A cylindrical coordinate system has been defined on the image space after curved multiplanar reformation of the coronary vessel for the comprehensive visualization of the main vessel features such as wall thickening and calcium content. A novel semi-automatic segmentation procedure based on 2D histograms has been implemented and the quantitative results validated by histology. The potentiality of attenuation-based micro-CT at low kV to reliably separate arterial wall layers from adjacent tissue as well as identify wall and plaque contours and major tissue components has been validated by histology. Morphometric indexes from histological data corresponding to several micro-CT slices have been derived (double observer evaluation at different coronary ATS stages) and highly significant correlations (R2 > 0.90) evidenced. Semi-automatic morphometry has been validated by double observer manual morphometry of micro-CT slices and highly significant correlations were found (R2 > 0.92). The micro-CT methodology described represents a handy and reliable tool for quantitative high resolution and contrast agent free full length coronary wall profiling, able to assist atherosclerotic vessels morphometry in a preclinical experimental model of coronary ATS and providing a link between in vivo imaging and histology.

A Workstation for Interactive Display and Quantitative Analysis of 3-D and 4-D Biomedical Images

PubMed Central

Robb, R.A.; Heffeman, P.B.; Camp, J.J.; Hanson, D.P.

1986-01-01

The capability to extract objective and quantitatively accurate information from 3-D radiographic biomedical images has not kept pace with the capabilities to produce the images themselves. This is rather an ironic paradox, since on the one hand the new 3-D and 4-D imaging capabilities promise significant potential for providing greater specificity and sensitivity (i.e., precise objective discrimination and accurate quantitative measurement of body tissue characteristics and function) in clinical diagnostic and basic investigative imaging procedures than ever possible before, but on the other hand, the momentous advances in computer and associated electronic imaging technology which have made these 3-D imaging capabilities possible have not been concomitantly developed for full exploitation of these capabilities. Therefore, we have developed a powerful new microcomputer-based system which permits detailed investigations and evaluation of 3-D and 4-D (dynamic 3-D) biomedical images. The system comprises a special workstation to which all the information in a large 3-D image data base is accessible for rapid display, manipulation, and measurement. The system provides important capabilities for simultaneously representing and analyzing both structural and functional data and their relationships in various organs of the body. This paper provides a detailed description of this system, as well as some of the rationale, background, theoretical concepts, and practical considerations related to system implementation. ImagesFigure 5Figure 7Figure 8Figure 9Figure 10Figure 11Figure 12Figure 13Figure 14Figure 15Figure 16

Polyp measurement with CT colonography: multiple-reader, multiple-workstation comparison.

PubMed

Young, Brett M; Fletcher, J G; Paulsen, Scott R; Booya, Fargol; Johnson, C Daniel; Johnson, Kristina T; Melton, Zackary; Rodysill, Drew; Mandrekar, Jay

2007-01-01

The risk of invasive colorectal cancer in colorectal polyps correlates with lesion size. Our purpose was to define the most accurate methods for measuring polyp size at CT colonography (CTC) using three models of workstations and multiple observers. Six reviewers measured 24 unique polyps of known size (5, 7, 10, and 12 mm), shape (sessile, flat, and pedunculated), and location (straight or curved bowel segment) using CTC data sets obtained at two doses (5 mAs and 65 mAs) and a previously described colonic phantom model. Reviewers measured the largest diameter of polyps on three proprietary workstations. Each polyp was measured with lung and soft-tissue windows on axial, 2D multiplanar reconstruction (MPR), and 3D images. There were significant differences among measurements obtained at various settings within each workstation (p < 0.0001). Measurements on 2D images were more accurate with lung window than with soft-tissue window settings (p < 0.0001). For the 65-mAs data set, the most accurate measurements were obtained in analysis of axial images with lung window, 2D MPR images with lung window, and 3D tissue cube images for Wizard, Advantage, and Vitrea workstations, respectively, without significant differences in accuracy among techniques (0.11 < p < 0.59). The mean absolute error values for these optimal settings were 0.48 mm, 0.61 mm, and 0.76 mm, respectively, for the three workstations. Within the ultralow-dose 5-mAs data set the best methods for Wizard, Advantage, and Vitrea were axial with lung window, 2D MPR with lung window, and 2D MPR with lung window, respectively. Use of nearly all measurement methods, except for the Vitrea 3D tissue cube and the Wizard 2D MPR with lung window, resulted in undermeasurement of the true size of the polyps. Use of CTC computer workstations facilitates accurate polyp measurement. For routine CTC examinations, polyps should be measured with lung window settings on 2D axial or MPR images (Wizard and Advantage) or 3D images (Vitrea). When these optimal methods are used, these three commercial workstations do not differ significantly in acquisition of accurate polyp measurements at routine dose settings.

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

PubMed

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors.

Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion.

PubMed

Boileau, Pascal; Morin-Salvo, Nicolas; Gauci, Marc-Olivier; Seeto, Brian L; Chalmers, Peter N; Holzer, Nicolas; Walch, Gilles

2017-12-01

Glenoid deficiency and erosion (excessive retroversion/inclination) must be corrected in reverse shoulder arthroplasty (RSA) to avoid prosthetic notching or instability and to maximize function, range of motion, and prosthesis longevity. This study reports the results of RSA with an angled, autologous glenoid graft harvested from the humerus (angled BIO-RSA). A trapezoidal bone graft, harvested from the humeral head and fixed with a long-post baseplate and screws, was used to compensate for residual glenoid bone loss/erosion. For simple to moderate (<25°) glenoid defects, standardized instrumentation combined with some eccentric reaming (<15°) was used to reconstruct the glenoid and obtain neutral implant alignment. For severe (>25°) and complex (multiplanar) glenoid bone defects, patient-specific grafts and guides were used after 3-dimensional planning. Patients were reviewed with minimum 2 years of follow-up. Mean follow-up was 36 months (range, 24-81 months). Preoperative and postoperative measurements of inclination and version were performed in the plane of the scapula on computed tomography images. The study included 54 patients (41 women, 13 men; mean 73 years old). Fifteen patients had combined vertical and horizontal glenoid bone deficiency. Among E2/E3 glenoids, inclination improved from 37° (range, 14° to 84°) to 10.2° (range -28° to 36°, P < .001). Among B2/C glenoids, retroversion improved from -21° (range, -49° to 0°) to -10.6° (-32° to 4°, P = .06). Complete radiographic incorporation of the graft occurred in 94% (51 of 54). Complications included infection in 1 and clinical aseptic baseplate loosening in 2. Mild notching occurred in 25% (13 of 51) of patients. Constant-Murley and Subjective Shoulder Value assessments increased from 31 to 68 and from 30% to 83%, respectively (P < .001). Angled BIO-RSA predictably corrects glenoid deficiency, including severe (>25°) multiplanar deformity. Graft incorporation is predictable. Advantages of using an autograftharvested in situ include bone stock augmentation, lateralization, low donor-site morbidity, low relative cost, and flexibility needed to simultaneously correct posterior and superior glenoid defects. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

MR imaging and proton spectroscopy of the breast: how to select the images useful to convey the diagnostic message.

PubMed

Fausto, A; Magaldi, A; Babaei Paskeh, B; Menicagli, L; Lupo, E N; Sardanelli, F

2007-10-01

The purpose of this study was to propose a short way to summarise a breast magnetic resonance (MR) examination including a precontrast and contrast-enhanced dynamic study and proton spectroscopy (1H-MRS) in order to convey the diagnostic message. At the Department of Radiology of the Policlinico San Donato (University of Milan), breast MR is routinely performed at 1.5 T as follows: 36-slice axial 2D short-time inversion-recovery (STIR) sequence; 128-partition 3D gradient-echo coronal sequence (1-mm3 siotropic voxel) before and after rapid automatic intravenous injection of 0.1 mmol/kg of Gd-DOTA (one precontrast and four postcontrast phases). Postprocessing includes temporal subtraction (postcontrast minus precontrast), maximum intensity projections (MIPs), percent enhancement-to-time curves for small regions of interest, and axial and/or sagittal multiplanar reconstructions. Single-voxel 1H-MRS is acquired to characterise focal lesions. Applying this protocol, more than 1,200 images are generated for each examination. We select only four MIPs of an early subtracted dynamic phase: one axial similar to craniocaudal x-ray mammographic views, one coronal, and two lateral similar to lateral 90 degrees x-ray mammographic views. For each lesion described in the report, we select five items, including three images, one graph, and one table: STIR image, precontrast and subtracted postcontrast images (morphology), percent enhancement-to-time curves and a table of raw data generating the curves (dynamics). If 1H-MRS has been performed, we add other five items: two postprocessed spectra (metabolism) and three images localising the volume of interest. Only the selected items are printed on films and attached to the report. The selected items range usually from four (no detected lesion) to 14 (one lesion, studied also with 1H-MRS), to 44 (five lesions, one of them studied also with 1H-MRS). The percentage of items presented with the report if compared with the total number of generated images is equal to 0.33% (4/1,200), 1.17% (14/1,200), and 2.83% (34/1,200), respectively. Breast MR imaging and 1H-MRS can be effectively summarised presenting only a minimal fraction of all generated images.

Imaging autofluorescence temporal signatures of the human ocular fundus in vivo

NASA Astrophysics Data System (ADS)

Papour, Asael; Taylor, Zachary; Stafsudd, Oscar; Tsui, Irena; Grundfest, Warren

2015-11-01

We demonstrate real-time in vivo fundus imaging capabilities of our fluorescence lifetime imaging technology for the first time. This implementation of lifetime imaging uses light emitting diodes to capture full-field images capable of showing direct tissue contrast without executing curve fitting or lifetime calculations. Preliminary results of fundus images are presented, investigating autofluorescence imaging potential of various retina biomarkers for early detection of macular diseases.

Multislice computed tomographic findings of the anomalous origins of the right coronary artery: evaluation of possible causes of myocardial ischemia.

PubMed

Ichikawa, Makoto; Sato, Yuichi; Komatsu, Sei; Hirayama, Atsushi; Kodama, Kazuhisa; Saito, Satoshi

2007-06-01

Anomalous right coronary arteries (RCA) arising from the left sinus of Valsalva may cause myocardial ischemia. We evaluated morphological features of anomalous RCA by using multislice computed tomography (MSCT) in relation to myocardial ischemia provoked by myocardial perfusion single-photon emission computed tomography. MSCT was performed in a total of 3, 212 patients by using an Aquillion 16 and a Light Speed Ultra. Retrospective ECG-gated image reconstruction was performed. Volume rendering, axial and curved multiplanar reformatted images were analyzed for the determination of the origin and course of the RCA, the take-off angle of the RCA from the aorta, and size of the RCA orifice. Furthermore, virtual angioscopic images were also used for the evaluation of the RCA orifice structure. Anomalous origins of the RCA were found in 15 patients. In 13 patients, the RCA arose from the left sinus of Valsalva, and in 2 patients it arose from the left main coronary artery as a single coronary artery. The RCA coursed anteriorly between the ascending aorta and pulmonary artery in 14 patients, whereas it had a retroaortic course in 1 patient. Acute angle take-off (<30 degrees ) of the RCA from the aorta and the left main coronary artery was observed in 8 patients, intramural course of the RCA within the aortic wall was observed in 6 patients and a small RCA orifice was observed in 4 patients. Exercise-induced myocardial ischemia was present in 5 patients. Coursing between the aorta and pulmonary artery, acute angle take-off and intramural course were thought to be major causes of exercise-induced ischemia in patients with anomalous origins of the RCA.

Imaging of Pericardiophrenic Bundles Using Multislice Spiral Computed Tomography for Phrenic Nerve Anatomy.

PubMed

Wang, Yan-Jing; Liu, Lin; Zhang, Meng-Chao; Sun, Huan; Zeng, Hong; Yang, Ping

2016-08-01

Phrenic nerve injury and diaphragmatic stimulation are common complications following arrhythmia ablation and pacing therapies. Preoperative comprehension of phrenic nerve anatomy via non-invasive CT imaging may help to minimize the electrophysiological procedure-related complications. Coronary CT angiography data of 121 consecutive patients were collected. Imaging of left and right pericardiophrenic bundles was performed with volume rendering and multi-planar reformation techniques. The shortest spatial distances between phrenic nerves and key electrophysiology-related structures were determined. The frequencies of the shortest distances ≤5 mm, >5 mm and direct contact between phrenic nerves and adjacent structures were calculated. Left and right pericardiophrenic bundles were identified in 86.8% and 51.2% of the patients, respectively. The right phrenic nerve was <5 mm from right superior and inferior pulmonary veins in 92.0% and 3.2% of the patients, respectively. The percentage of right phrenic nerve, <5 mm from right atrium, superior caval vein, and superior caval vein-right atrium junction was 87.1%, 100%, and 62.9%, respectively. Left phrenic nerve was <5 mm from left atrial appendage, great cardiac vein, anterior and posterior interventricular veins, and left ventricular posterior veins in 81.9%, 1.0%, 39.1%, 28.6%, and 91.4% of the patients, respectively. Merely 0.06% left phrenic nerve had a distance <5 mm with left superior pulmonary vein, and none left phrenic nerve showed a distance <5 mm with left inferior pulmonary vein. One-stop enhanced CT scanning enabled detection of phrenic nerve anatomy, which might facilitate avoidance of the phrenic nerve-related complications in interventional electrophysiology. © 2016 Wiley Periodicals, Inc.

Needle placement for piriformis injection using 3-D imaging.

PubMed

Clendenen, Steven R; Candler, Shawn A; Osborne, Michael D; Palmer, Scott C; Duench, Stephanie; Glynn, Laura; Ghazi, Salim M

2013-01-01

Piriformis syndrome is a pain syndrome originating in the buttock and is attributed to 6% - 8% of patients referred for the treatment of back and leg pain. The treatment for piriformis syndrome using fluoroscopy, computed tomography (CT), electromyography (EMG), and ultrasound (US) has become standard practice. The treatment of Piriformis Syndrome has evolved to include fluoroscopy and EMG with CT guidance. We present a case study of 5 successful piriformis injections using 3-D computer-assisted electromagnet needle tracking coupled with ultrasound. A 6-degree of freedom electromagnetic position tracker was attached to the ultrasound probe that allowed the system to detect the position and orientation of the probe in the magnetic field. The tracked ultrasound probe was used to find the posterior superior iliac spine. Subsequently, 3 points were captured to register the ultrasound image with the CT or magnetic resonance image scan. Moreover, after the registration was obtained, the navigation system visualized the tracked needle relative to the CT scan in real-time using 2 orthogonal multi-planar reconstructions centered at the tracked needle tip. Conversely, a recent study revealed that fluoroscopically guided injections had 30% accuracy compared to ultrasound guided injections, which tripled the accuracy percentage. This novel technique exhibited an accurate needle guidance injection precision of 98% while advancing to the piriformis muscle and avoiding the sciatic nerve. The mean (± SD) procedure time was 19.08 (± 4.9) minutes. This technique allows for electromagnetic instrument tip tracking with real-time 3-D guidance to the selected target. As with any new technique, a learning curve is expected; however, this technique could offer an alternative, minimizing radiation exposure.

Dynamic helical computed tomography of the pituitary gland in healthy dogs.

PubMed

Van der Vlugt-Meijer, Roselinda H; Meij, Björn P; Voorhout, George

2007-01-01

Dynamic helical computed tomography (CT) of the pituitary gland can be used to image the three-dimensional shape and dimensions of abnormalities within the pituitary gland. The aim of this study was to develop a protocol for dynamic helical CT of the pituitary gland in healthy dogs as a future reference study for patients with pituitary disease. Dynamic helical series of nine scans of the pituitary gland during and following contrast medium injection were performed in six healthy dogs using the following protocols: a series with 1 mm collimation and a table feed per X-ray tube rotation of 2 mm (pitch of 2) in six dogs, a series with 2 mm collimation and pitch of 2 in three dogs, and a series with 1 mm collimation and pitch of 1 in three other dogs. Multiplanar reconstructions of the images were made using a reconstruction index of 0.5. Images of all series were assessed visually for enhancement of the arteries, the neurohypophysis, and the adenohypophysis. The enhancement pattern of the neurohypophysis was distinguished adequately from that of the adenohypophysis in five dogs that were scanned with 1 mm collimation and pitch of 2, but the difference was less discernable when the other protocols were used. The carotid artery, its trifurcation, and the arterial cerebral circle were best visualized in dorsal reconstructions. Dynamic helical CT of the pituitary gland in healthy dogs can be performed with 1 mm collimation and pitch of 2, and a scan length that includes the entire pituitary region. Using this protocol, with the specific scanner used, the neurohypophysis, the adenohypophysis, and the surrounding vascular structures are adequately visualized.

[Dual energy CT angiography of the carotid arteries: quality, bone subtraction, and radiation dosage using tube voltage 80/140 kV versus 100/140 kV].

PubMed

Santos Armentia, E; Tardáguila de la Fuente, G; Castellón Plaza, D; Delgado Sánchez-Gracián, C; Prada González, R; Fernández Fernández, L; Tardáguila Montero, F

2014-01-01

To study the differences in vascular image quality, bone subtraction, and dose of radiation of dual energy CT angiography of the supraaortic trunks using different tube voltages. We reviewed the CT angiograms of the supraaortic trunks in 46 patients acquired with a 128-slice dual source CT scanner using two voltage protocols (80/140 kV and 100/140 kV). The "head bone removal" tool was used for postprocessing. We divided the arteries into 15 segments. In each segment, we evaluated the image quality of the vessels and the effectiveness of bone removal in multiplanar reconstructions (MPR) and in maximum intensity projections (MIP) with each protocol, analyzing the trabecular and cortical bones separately. We also evaluated the dose of radiation received. Of the 46 patients, 13 were studied using 80/140 kV and 33 with 100/140 kV. There were no significant differences between the two groups in age or sex. Image quality in four segments was better in the group examined with 100/140 kV. Cortical bone removal in MPR and MIP and trabecular bone removal in MIP were also better in the group examined with 100/140 kV. The dose of radiation received was significantly higher in the group examined with 100/140 kV (1.16 mSv with 80/140 kV vs. 1.59 mSv with 100/140 kV). Using 100/140 kV increases the dose of radiation but improves the quality of the study of arterial segments and bone subtraction. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

The diagnosis of children with central diabetes insipidus.

PubMed

Ghirardello, Stefano; Garrè, Maria-Luisa; Rossi, Andrea; Maghnie, Mohamad

2007-03-01

Central diabetes insipidus is the end result of a number of different diseases that affect the hypothalamic-neurohypophyseal system. In many patients, especially children and young adults, it is caused by the destruction or degeneration of neurons that originate in the supraoptic and paraventricular nuclei of the hypothalamus. The known causes of these lesions include germinoma or craniopharyngioma; Langerhans cell histiocytosis; local inflammatory, autoimmune or vascular diseases; trauma resulting from surgery or an accident; sarcoidosis; metastases; and midline cerebral and cranial malformations. In rare cases, genetic defects in AVP synthesis that are inherited as autosomal dominant, autosomal recessive or X-linked recessive traits are the underlying cause. Accurate diagnostic differentiation is essential for both safe and effective disease management. Proper etiological diagnosis can be achieved via a series of steps that start with clinical observations and then progress, as needed, to more sophisticated methods. Indeed, magnetic resonance imaging (MRI) represents the examination method of choice for evaluating hypothalamic-pituitary-related endocrine diseases due to its ability to provide strongly-contrasted high-resolution multi-planar and spatial images. Specifically, MRI allows a detailed and precise anatomical study of the pituitary gland by differentiating between the anterior and posterior pituitary lobes. MRI identification of pituitary hyperintensity in the posterior part of the sella, now considered to be a clear marker of neurohypophyseal functional integrity, together with careful analysis of pituitary stalk shape and size, have provided the most striking recent findings contributing to the diagnosis and understanding of some forms of 'idiopathic' central diabetes insipidus.

Open-MRI measures of cam intrusion for hips in an anterior impingement position relate to acetabular contact force.

PubMed

Buchan, Lawrence L; Zhang, Honglin; Konan, Sujith; Heaslip, Ingrid; Ratzlaff, Charles R; Wilson, David R

2016-02-01

Open MRI in functional positions has potential to directly and non-invasively assess cam femoroacetabular impingement (FAI). Our objective was to investigate whether open MRI can depict intrusion of the cam deformity into the intra-articular joint space, and whether intrusion is associated with elevated acetabular contact force. Cadaver hips (9 cam; 3 controls) were positioned in an anterior impingement posture and imaged using open MRI with multi-planar reformatting. The β-angle (describing clearance between the femoral neck and acetabulum) was measured around the entire circumference of the femoral neck. We defined a binary "MRI cam-intrusion sign" (positive if β < 0°). We then instrumented each hip with a piezoresistive sensor and conducted six repeated positioning trials, measuring acetabular contact force (F). We defined a binary "contact-force sign" (positive if F > 20N). Cam hips were more likely than controls to have both a positive MRI cam-intrusion sign (p = 0.0182, Fisher's exact test) and positive contact-force sign (p = 0.0083), which represents direct experimental evidence for cam intrusion. There was also a relationship between the MRI cam-intrusion sign and contact-force sign (p = 0.033), representing a link between imaging and mechanics. Our findings indicate that open MRI has significant potential for in vivo investigation of the cam FAI mechanism. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

An Investigation of the Morphology of the Petrotympanic Fissure Using Cone-Beam Computed Tomography

PubMed Central

Syriopoulos, Konstantinos; Sens, Rogier L.; Politis, Constantinus

2018-01-01

ABSTRACT Objectives The purpose of the present study was: a) to examine the visibility and morphology of the petrotympanic fissure on cone-beam computed tomography images, and b) to investigate whether the petrotympanic fissure morphology is significantly affected by gender and age, or not. Material and Methods Using Newtom VGi (QR Verona, Italy), 106 cone-beam computed tomography examinations (212 temporomandibular joint areas) of both genders were retrospectively and randomly selected. Two observers examined the images and subsequently classified by consensus the petrotympanic fissure morphology into the following three types: type 1 - widely open; type 2 - narrow middle; type 3 - very narrow/closed. Results The petrotympanic fissure morphology was assessed as type 1, type 2, and type 3 in 85 (40.1%), 72 (34.0%), and 55 (25.9%) cases, respectively. No significant difference was found between left and right petrotympanic fissure morphology (Kappa = 0.37; P < 0.001). Furthermore, no significant difference was found between genders, specifically P = 0.264 and P = 0.211 for the right and left petrotympanic fissure morphology, respectively. However, the ordinal logistic regression analysis showed that males tend to have narrower petrotympanic fissures, in particular OR = 1.58 for right and OR = 1.5 for left petrotympanic fissure. Conclusions The current study lends support to the conclusion that an enhanced multi-planar cone-beam computed tomography yields a clear depiction of the petrotympanic fissure's morphological characteristics. We have found that the morphology is neither gender nor age-related. PMID:29707183

An Investigation of the Morphology of the Petrotympanic Fissure Using Cone-Beam Computed Tomography.

PubMed

Damaskos, Spyros; Syriopoulos, Konstantinos; Sens, Rogier L; Politis, Constantinus

2018-01-01

The purpose of the present study was: a) to examine the visibility and morphology of the petrotympanic fissure on cone-beam computed tomography images, and b) to investigate whether the petrotympanic fissure morphology is significantly affected by gender and age, or not. Using Newtom VGi (QR Verona, Italy), 106 cone-beam computed tomography examinations (212 temporomandibular joint areas) of both genders were retrospectively and randomly selected. Two observers examined the images and subsequently classified by consensus the petrotympanic fissure morphology into the following three types: type 1 - widely open; type 2 - narrow middle; type 3 - very narrow/closed. The petrotympanic fissure morphology was assessed as type 1, type 2, and type 3 in 85 (40.1%), 72 (34.0%), and 55 (25.9%) cases, respectively. No significant difference was found between left and right petrotympanic fissure morphology (Kappa = 0.37; P < 0.001). Furthermore, no significant difference was found between genders, specifically P = 0.264 and P = 0.211 for the right and left petrotympanic fissure morphology, respectively. However, the ordinal logistic regression analysis showed that males tend to have narrower petrotympanic fissures, in particular OR = 1.58 for right and OR = 1.5 for left petrotympanic fissure. The current study lends support to the conclusion that an enhanced multi-planar cone-beam computed tomography yields a clear depiction of the petrotympanic fissure's morphological characteristics. We have found that the morphology is neither gender nor age-related.

Radiologic and functional evaluation of electrode dislocation from the scala tympani to the scala vestibuli in patients with cochlear implants.

PubMed

Fischer, N; Pinggera, L; Weichbold, V; Dejaco, D; Schmutzhard, J; Widmann, G

2015-02-01

Localization of the electrode after cochlear implantation seems to have an impact on auditory outcome, and conebeam CT has emerged as a reliable method for visualizing the electrode array position within the cochlea. The aim of this retrospective study was to evaluate the frequency and clinical impact of scalar dislocation of various electrodes and surgical approaches and to evaluate its influence on auditory outcome. This retrospective single-center study analyzed a consecutive series of 63 cochlear implantations with various straight electrodes. The placement of the electrode array was evaluated by using multiplanar reconstructed conebeam CT images. For the auditory outcome, we compared the aided hearing thresholds and the charge units of maximum comfortable loudness level at weeks 6, 12, and 24 after implantation. In 7.9% of the cases, the electrode array showed scalar dislocation. In all cases, the electrode array penetrated the basal membrane within 45° of the electrode insertion. All 3 cases of cochleostomy were dislocated in the first 45° segment. No hearing differences were noted, but the charge units of maximum comfortable loudness level seemed to increase with time in patients with dislocations. The intracochlear dislocation rate of various straight electrodes detected by conebeam CT images is relatively low. Scalar dislocation may not negatively influence the hearing threshold but may require an increase of the necessary stimulus charge and should be reported by the radiologist. © 2015 by American Journal of Neuroradiology.

Computed tomography and magnetic resonance angiography in the evaluation of aberrant origin of the external carotid artery branches.

PubMed

Cappabianca, Salvatore; Scuotto, Assunta; Iaselli, Francesco; Pignatelli di Spinazzola, Nicoletta; Urraro, Fabrizio; Sarti, Giuseppe; Montemarano, Marcella; Grassi, Roberto; Rotondo, Antonio

2012-07-01

Aim of our study was to evaluate the prevalence of aberrant origin of the branches of the external carotid artery (ECA) in 97 patients by computed tomography (CTA) and magnetic resonance angiography (MRA) and to compare the accuracy of these two techniques in the visualization of the ECA system. All patients underwent CTA and MRA examination of the head and neck. Multiplanar and volumetric reformations were obtained in all cases. For each set of images, the presence of aberrant origin of the branches of the external carotid artery was investigated. MRA and CTA images of each patient were compared to define their information content. Anatomical anomalies were found in 88 heminecks, with a prevalence of 53.3%. In the 61 patients in whom the CTA was performed before the MRA, the latter method showed only 92% of abnormalities detected at the first examination; in the 36 patients in whom MRA was performed first, CTA identified all of the anomalies highlighted by the former, adding 12 new. Knowledge of the anomalies of origin of the ECA branches is essential for the head and neck surgeon; the high prevalence of anomalies found in our series as in the previous studies indicates the opportunity to perform a CTA or a MRA of the head and neck before any surgical or interventional procedure. CTA is the method of choice in the evaluation of anomalies of origin of the branches of the ECA and in the definition of their course.

Plenoptic Imaging of a Three Dimensional Cold Atom Cloud

NASA Astrophysics Data System (ADS)

Lott, Gordon

2017-04-01

A plenoptic imaging system is capable of sampling the rays of light in a volume, both spatially and angularly, providing information about the three dimensional (3D) volume being imaged. The extraction of the 3D structure of a cold atom cloud is demonstrated, using a single plenoptic camera and a single image. The reconstruction is tested against a reference image and the results discussed along with the capabilities and limitations of the imaging system. This capability is useful when the 3D distribution of the atoms is desired, such as determining the shape of an atom trap, particularly when there is limited optical access. Gratefully acknowledge support from AFRL.

Laser microbeam CT scanning of dosimetry gels

NASA Astrophysics Data System (ADS)

Maryanski, Marek J.; Ranade, Manisha K.

2001-06-01

A novel design of an optical tomographic scanner is described that can be used for 3D mapping of optical attenuation coefficient within translucent cylindrical objects with spatial resolution on the order of 100 microns. Our scanner design utilizes the cylindrical geometry of the imaged object to obtain the desired paths of the scanning light rays. A rotating mirror and a photodetector are placed at two opposite foci of the translucent cylinder that acts as a cylindrical lens. A He-Ne laser beam passes first through a focusing lens and then is reflected by the rotating mirror, so as to scan the interior of the cylinder with focused and parallel paraxial rays that are subsequently collected by the photodetector to produce the projection data, as the cylinder rotates in small angle increments between projections. Filtered backprojection is then used to reconstruct planar distributions of optical attenuation coefficient in the cylinder. Multiplanar scans are used to obtain a complete 3D tomographic reconstruction. Among other applications, the scanner can be used in radiation therapy dosimetry and quality assurance for mapping 3D radiation dose distributions in various types of tissue-equivalent gel phantoms that change their optical attenuation coefficients in proportion to the absorbed radiation dose.

The effect of breast support and breast pain on upper-extremity kinematics during running: implications for females with large breasts.

PubMed

White, Jennifer; Mills, Chris; Ball, Nick; Scurr, Joanna

2015-01-01

The relationship between inappropriate breast support and upper-extremity kinematics for female runners is unclear. The purpose of this study was to investigate the effect of breast support and breast pain on upper-extremity kinematics during running. Eleven female recreational runners with larger breasts (UK D and E cup) completed a 7 min 20 s treadmill run (2.58 m · s(-1)) in a high and low breast support condition. Multi-planar breast and upper-extremity kinematic data were captured in each breast support condition by eight infrared cameras for 30 s towards the end of the run. Breast pain was rated at the end of each treadmill run using a numeric analogue scale. The high support bra reduced breast kinematics and decreased breast pain (P < 0.05). Upper-extremity kinematics did not differ between breast support conditions (P > 0.05), although some moderate positive correlations were found between thorax range of motion and breast kinematics (r = 0.54 to 0.73). Thorax and arm kinematics do not appear to be influenced by breast support level in female runners with large breasts. A high support bra that offers good multi-planar breast support is recommended for female runners with larger breasts to reduce breast pain.

Non-perforated peptic ulcer disease: multidetector CT findings, complications, and differential diagnosis.

PubMed

Tonolini, Massimo; Ierardi, Anna Maria; Bracchi, Elena; Magistrelli, Paolo; Vella, Adriana; Carrafiello, Gianpaolo

2017-10-01

Despite availability of effective therapies, peptic ulcer disease (PUD) remains a major global disease, resulting from a combination of persistent Helicobacter pylori infection and widespread use of nonsteroidal anti-inflammatory drugs. Albeit endoscopy definitely represents the mainstay diagnostic technique, patients presenting to emergency departments with unexplained abdominal pain generally undergo multidetector CT as an initial investigation. Although superficial ulcers generally remain inconspicuous, careful multiplanar CT interpretation may allow to detect deep ulcers, secondary mural and extraluminal signs of peptic gastroduodenitis, thereby allowing timely endoscopic verification and appropriate treatment. This pictorial essay aims to provide radiologists with an increased familiarity with CT diagnosis of non-perforated PUD, with emphasis on differential diagnosis. Following an overview of current disease epidemiology and complications, it explains the appropriate CT acquisition and interpretation techniques, and reviews with several examples the cross-sectional findings of uncomplicated PUD. Afterwards, the CT features of PUD complications such as ulcer haemorrhage, gastric outlet obstruction, biliary and pancreatic fistulisation are presented. • Gastric and duodenal peptic ulcers are increasingly caused by nonsteroidal anti-inflammatory drugs • Multiplanar CT interpretation allows detecting deep ulcers and secondary signs of gastroduodenitis • CT diagnosis of uncomplicated peptic disease relies on direct and indirect signs • Currently the commonest complication, haemorrhage may be treated with transarterial embolisation • Other uncommon complications include gastric outlet obstruction and biliopancreatic fistulisation.

Cyst infection in hospital-admitted autosomal dominant polycystic kidney disease patients is predominantly multifocal and associated with kidney and liver volume

PubMed Central

Balbo, B.E.P.; Sapienza, M.T.; Ono, C.R.; Jayanthi, S.K.; Dettoni, J.B.; Castro, I.; Onuchic, L.F.

2014-01-01

Positron-emission tomography/computed tomography (PET/CT) has improved cyst infection (CI) management in autosomal dominant polycystic kidney disease (ADPKD). The determinants of kidney and/or liver involvement, however, remain uncertain. In this study, we evaluated clinical and imaging factors associated with CI in kidney (KCI) and liver (LCI) in ADPKD. A retrospective cohort study was performed in hospital-admitted ADPKD patients with suspected CI. Clinical, imaging and surgical data were analyzed. Features of infected cysts were evaluated by PET/CT. Total kidney (TKV) and liver (TLV) volumes were measured by CT-derived multiplanar reconstruction. CI was detected in 18 patients who experienced 24 episodes during an interval of 30 months (LCI in 12, KCI in 10 and concomitant infection in 2). Sensitivities of CT, magnetic resonance imaging and PET/CT were 25.0, 71.4, and 95.0%. Dysuria (P<0.05), positive urine culture (P<0.01), and previous hematuria (P<0.05) were associated with KCI. Weight loss (P<0.01) and increased C-reactive protein levels (P<0.05) were associated with LCI. PET/CT revealed that three or more infected cysts were present in 70% of the episodes. TKV was higher in kidney-affected than in LCI patients (AUC=0.91, P<0.05), with a cut-off of 2502 mL (72.7% sensitivity, 100.0% specificity). TLV was higher in liver-affected than in KCI patients (AUC=0.89, P<0.01) with a cut-off of 2815 mL (80.0% sensitivity, 87.5% specificity). A greater need for invasive procedures was observed in LCI (P<0.01), and the overall mortality was 20.8%. This study supports PET/CT as the most sensitive imaging method for diagnosis of cyst infection, confirms the multifocal nature of most hospital-admitted episodes, and reveals an association of kidney and liver volumes with this complication. PMID:24919173

Real-time virtual sonography, a coordinated sonography and MRI system that uses magnetic navigation, improves the sonographic identification of enhancing lesions on breast MRI.

PubMed

Nakano, Shogo; Yoshida, Miwa; Fujii, Kimihito; Yorozuya, Kyoko; Kousaka, Junko; Mouri, Yukako; Fukutomi, Takashi; Ohshima, Yukihiko; Kimura, Junko; Ishiguchi, Tsuneo

2012-01-01

This study verified that recently developed real-time virtual sonography (RVS) to coordinate a sonography image and the magnetic resonance imaging (MRI) multiplanar reconstruction (MPR) with magnetic navigation was useful. The purpose of this study was to evaluate the accuracy of RVS to sonographically identify enhancing lesions by breast MRI. Between December 2008 and May 2009, RVS was performed in 51 consecutive patients with 63 enhancing lesions. MRI was performed with the patients in the supine position using a 1.5-T imager with a body surface coil to achieve the same position as with sonography. To assess the accuracy of the RVS, the following three issues were analyzed: (i) The sonographic detection rate of enhancing lesions, (ii) the comparison of the tumor size measured by sonography and the MRI-MPR and (iii) the positioning errors as the distance from the actual sonographic position to the expected MRI position in 3-D. Among the 63 enhancing lesions, 42 (67%) lesions were identified by conventional B-mode, whereas the remaining 21 (33%) initial conventional B-mode occult lesions were identified by RVS alone. The sonographic size of the lesions detected by RVS alone was significantly smaller than that of lesions detected by conventional B-mode (p < 0.001). The mean tumor size provided by RVS was 12.3 mm for real-time sonography and 14.1 mm for MRI-MPR (r = 0.848, p < 0.001). The mean positioning errors for the transverse and sagittal planes and the depth from the skin were 7.7, 6.9 and 2.8 mm, respectively. The overall mean 3D positioning error was 12.0 mm. Our results suggest that RVS has good targeting accuracy to directly compare a sonographic image with MRI results without operator dependence. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Three-dimensional ultrasound imaging and measurement of nasal bone length, prenasal thickness and frontomaxillary facial angle in normal second- and third-trimester fetuses.

PubMed

Vos, F I; De Jong-Pleij, E A P; Ribbert, L S M; Tromp, E; Bilardo, C M

2012-06-01

To assess the feasibility of nasal bone length (NBL), prenasal thickness (PT) and frontomaxillary facial (FMF) angle measurements performed on the same three-dimensional (3D) multiplanar-corrected profile view in healthy second- and third-trimester fetuses, to create reference ranges and to review published measurement techniques. 3D volumes of 219 healthy second- and third-trimester fetuses were retrospectively analyzed. The quality of images and measurability of the markers were assessed with 5-point and 3-point scoring systems, respectively. Measurements of NBL (with care to exclude the frontal bone), PT and FMF were obtained in the exact mid-sagittal plane. Reference ranges were constructed based on measurements from images with high-quality (4 or 5 points) and high measurability (2 or 3 points) scores and compared with those in the most relevant published literature. A high-quality score was assigned to 111 images. Among these, a high measurability score was significantly more often achieved for NBL (98.2%) and PT (97.3%) than for the FMF angle (26.1%) (P < 0.001). Both NBL (NBL = - 6.927 + (0.83 × GA) - (0.01 × GA(2))) and PT (PT = (0.212 × GA) - 0.873) (where GA = gestational age) showed growth with gestation, with less pronounced growth for NBL after 28 weeks. Our reference range for the NBL showed a systematically smaller length than those in other two-dimensional (2D) ultrasound-based publications. The FMF angle measurements that we obtained did not show a significant change with GA. NBL and PT are easily measured using 3D ultrasound whereas FMF angle measurement is more challenging. When it is measured in the exact mid-sagittal plane and care is taken to exclude the frontal bone, measurements of the NBL are systematically smaller than those in previous 2D ultrasound-based publications. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

Angle-independent measure of motion for image-based gating in 3D coronary angiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehmann, Glen C.; Holdsworth, David W.; Drangova, Maria

2006-05-15

The role of three-dimensional (3D) image guidance for interventional procedures and minimally invasive surgeries is increasing for the treatment of vascular disease. Currently, most interventional procedures are guided by two-dimensional x-ray angiography, but computed rotational angiography has the potential to provide 3D geometric information about the coronary arteries. The creation of 3D angiographic images of the coronary arteries requires synchronization of data acquisition with respect to the cardiac cycle, in order to minimize motion artifacts. This can be achieved by inferring the extent of motion from a patient's electrocardiogram (ECG) signal. However, a direct measurement of motion (from the 2Dmore » angiograms) has the potential to improve the 3D angiographic images by ensuring that only projections acquired during periods of minimal motion are included in the reconstruction. This paper presents an image-based metric for measuring the extent of motion in 2D x-ray angiographic images. Adaptive histogram equalization was applied to projection images to increase the sharpness of coronary arteries and the superior-inferior component of the weighted centroid (SIC) was measured. The SIC constitutes an image-based metric that can be used to track vessel motion, independent of apparent motion induced by the rotational acquisition. To evaluate the technique, six consecutive patients scheduled for routine coronary angiography procedures were studied. We compared the end of the SIC rest period ({rho}) to R-waves (R) detected in the patient's ECG and found a mean difference of 14{+-}80 ms. Two simultaneous angular positions were acquired and {rho} was detected for each position. There was no statistically significant difference (P=0.79) between {rho} in the two simultaneously acquired angular positions. Thus we have shown the SIC to be independent of view angle, which is critical for rotational angiography. A preliminary image-based gating strategy that employed the SIC was compared to an ECG-based gating strategy in a porcine model. The image-based gating strategy selected 61 projection images, compared to 45 selected by the ECG-gating strategy. Qualitative comparison revealed that although both the SIC-based and ECG-gated reconstructions decreased motion artifact compared to reconstruction with no gating, the SIC-based gating technique increased the conspicuity of smaller vessels when compared to ECG gating in maximum intensity projections of the reconstructions and increased the sharpness of a vessel cross section in multi-planar reformats of the reconstruction.« less

MOPEX: a software package for astronomical image processing and visualization

NASA Astrophysics Data System (ADS)

Makovoz, David; Roby, Trey; Khan, Iffat; Booth, Hartley

2006-06-01

We present MOPEX - a software package for astronomical image processing and display. The package is a combination of command-line driven image processing software written in C/C++ with a Java-based GUI. The main image processing capabilities include creating mosaic images, image registration, background matching, point source extraction, as well as a number of minor image processing tasks. The combination of the image processing and display capabilities allows for much more intuitive and efficient way of performing image processing. The GUI allows for the control over the image processing and display to be closely intertwined. Parameter setting, validation, and specific processing options are entered by the user through a set of intuitive dialog boxes. Visualization feeds back into further processing by providing a prompt feedback of the processing results. The GUI also allows for further analysis by accessing and displaying data from existing image and catalog servers using a virtual observatory approach. Even though originally designed for the Spitzer Space Telescope mission, a lot of functionalities are of general usefulness and can be used for working with existing astronomical data and for new missions. The software used in the package has undergone intensive testing and benefited greatly from effective software reuse. The visualization part has been used for observation planning for both the Spitzer and Herschel Space Telescopes as part the tool Spot. The visualization capabilities of Spot have been enhanced and integrated with the image processing functionality of the command-line driven MOPEX. The image processing software is used in the Spitzer automated pipeline processing, which has been in operation for nearly 3 years. The image processing capabilities have also been tested in off-line processing by numerous astronomers at various institutions around the world. The package is multi-platform and includes automatic update capabilities. The software package has been developed by a small group of software developers and scientists at the Spitzer Science Center. It is available for distribution at the Spitzer Science Center web page.

The history of MR imaging as seen through the pages of radiology.

PubMed

Edelman, Robert R

2014-11-01

The first reports in Radiology pertaining to magnetic resonance (MR) imaging were published in 1980, 7 years after Paul Lauterbur pioneered the first MR images and 9 years after the first human computed tomographic images were obtained. Historical advances in the research and clinical applications of MR imaging very much parallel the remarkable advances in MR imaging technology. These advances can be roughly classified into hardware (eg, magnets, gradients, radiofrequency [RF] coils, RF transmitter and receiver, MR imaging-compatible biopsy devices) and imaging techniques (eg, pulse sequences, parallel imaging, and so forth). Image quality has been dramatically improved with the introduction of high-field-strength superconducting magnets, digital RF systems, and phased-array coils. Hybrid systems, such as MR/positron emission tomography (PET), combine the superb anatomic and functional imaging capabilities of MR imaging with the unsurpassed capability of PET to demonstrate tissue metabolism. Supported by the improvements in hardware, advances in pulse sequence design and image reconstruction techniques have spurred dramatic improvements in imaging speed and the capability for studying tissue function. In this historical review, the history of MR imaging technology and developing research and clinical applications, as seen through the pages of Radiology, will be considered.

Extending the imaging volume for biometric iris recognition.

PubMed

Narayanswamy, Ramkumar; Johnson, Gregory E; Silveira, Paulo E X; Wach, Hans B

2005-02-10

The use of the human iris as a biometric has recently attracted significant interest in the area of security applications. The need to capture an iris without active user cooperation places demands on the optical system. Unlike a traditional optical design, in which a large imaging volume is traded off for diminished imaging resolution and capacity for collecting light, Wavefront Coded imaging is a computational imaging technology capable of expanding the imaging volume while maintaining an accurate and robust iris identification capability. We apply Wavefront Coded imaging to extend the imaging volume of the iris recognition application.

A trillion frames per second: the techniques and applications of light-in-flight photography.

PubMed

Faccio, Daniele; Velten, Andreas

2018-06-14

Cameras capable of capturing videos at a trillion frames per second allow to freeze light in motion, a very counterintuitive capability when related to our everyday experience in which light appears to travel instantaneously. By combining this capability with computational imaging techniques, new imaging opportunities emerge such as three dimensional imaging of scenes that are hidden behind a corner, the study of relativistic distortion effects, imaging through diffusive media and imaging of ultrafast optical processes such as laser ablation, supercontinuum and plasma generation. We provide an overview of the main techniques that have been developed for ultra-high speed photography with a particular focus on `light in flight' imaging, i.e. applications where the key element is the imaging of light itself at frame rates that allow to freeze it's motion and therefore extract information that would otherwise be blurred out and lost. . © 2018 IOP Publishing Ltd.

MRI of the lumbar spine: comparison of 3D isotropic turbo spin-echo SPACE sequence versus conventional 2D sequences at 3.0 T.

PubMed

Lee, Sungwon; Jee, Won-Hee; Jung, Joon-Yong; Lee, So-Yeon; Ryu, Kyeung-Sik; Ha, Kee-Yong

2015-02-01

Three-dimensional (3D) fast spin-echo sequence with variable flip-angle refocusing pulse allows retrospective alignments of magnetic resonance imaging (MRI) in any desired plane. To compare isotropic 3D T2-weighted (T2W) turbo spin-echo sequence (TSE-SPACE) with standard two-dimensional (2D) T2W TSE imaging for evaluating lumbar spine pathology at 3.0 T MRI. Forty-two patients who had spine surgery for disk herniation and had 3.0 T spine MRI were included in this study. In addition to standard 2D T2W TSE imaging, sagittal 3D T2W TSE-SPACE was obtained to produce multiplanar (MPR) images. Each set of MR images from 3D T2W TSE and 2D TSE-SPACE were independently scored for the degree of lumbar neural foraminal stenosis, central spinal stenosis, and nerve compression by two reviewers. These scores were compared with operative findings and the sensitivities were evaluated by McNemar test. Inter-observer agreements and the correlation with symptoms laterality were assessed with kappa statistics. The 3D T2W TSE and 2D TSE-SPACE had similar sensitivity in detecting foraminal stenosis (78.9% versus 78.9% in 32 foramen levels), spinal stenosis (100% versus 100% in 42 spinal levels), and nerve compression (92.9% versus 81.8% in 59 spinal nerves). The inter-observer agreements (κ = 0.849 vs. 0.451 for foraminal stenosis, κ = 0.809 vs. 0.503 for spinal stenosis, and κ = 0.681 vs. 0.429 for nerve compression) and symptoms correlation (κ = 0.449 vs. κ = 0.242) were better in 3D TSE-SPACE compared to 2D TSE. 3D TSE-SPACE with oblique coronal MPR images demonstrated better inter-observer agreements compared to 3D TSE-SPACE without oblique coronal MPR images (κ = 0.930 vs. κ = 0.681). Isotropic 3D T2W TSE-SPACE at 3.0 T was comparable to 2D T2W TSE for detecting foraminal stenosis, central spinal stenosis, and nerve compression with better inter-observer agreements and symptom correlation. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Multicenter accuracy and interobserver agreement of spot sign identification in acute intracerebral hemorrhage.

PubMed

Huynh, Thien J; Flaherty, Matthew L; Gladstone, David J; Broderick, Joseph P; Demchuk, Andrew M; Dowlatshahi, Dar; Meretoja, Atte; Davis, Stephen M; Mitchell, Peter J; Tomlinson, George A; Chenkin, Jordan; Chia, Tze L; Symons, Sean P; Aviv, Richard I

2014-01-01

Rapid, accurate, and reliable identification of the computed tomography angiography spot sign is required to identify patients with intracerebral hemorrhage for trials of acute hemostatic therapy. We sought to assess the accuracy and interobserver agreement for spot sign identification. A total of 131 neurology, emergency medicine, and neuroradiology staff and fellows underwent imaging certification for spot sign identification before enrolling patients in 3 trials targeting spot-positive intracerebral hemorrhage for hemostatic intervention (STOP-IT, SPOTLIGHT, STOP-AUST). Ten intracerebral hemorrhage cases (spot-positive/negative ratio, 1:1) were presented for evaluation of spot sign presence, number, and mimics. True spot positivity was determined by consensus of 2 experienced neuroradiologists. Diagnostic performance, agreement, and differences by training level were analyzed. Mean accuracy, sensitivity, and specificity for spot sign identification were 87%, 78%, and 96%, respectively. Overall sensitivity was lower than specificity (P<0.001) because of true spot signs incorrectly perceived as spot mimics. Interobserver agreement for spot sign presence was moderate (k=0.60). When true spots were correctly identified, 81% correctly identified the presence of single or multiple spots. Median time needed to evaluate the presence of a spot sign was 1.9 minutes (interquartile range, 1.2-3.1 minutes). Diagnostic performance, interobserver agreement, and time needed for spot sign evaluation were similar among staff physicians and fellows. Accuracy for spot identification is high with opportunity for improvement in spot interpretation sensitivity and interobserver agreement particularly through greater reliance on computed tomography angiography source data and awareness of limitations of multiplanar images. Further prospective study is needed.

Percutaneous cannulated screw fixation of sacral fractures and sacroiliac joint disruptions with CT-controlled guidewires performed by interventionalists: single center experience in treating posterior pelvic instability.

PubMed

Fischer, Sebastian; Vogl, Thomas J; Marzi, Ingo; Zangos, Stephan; Wichmann, Julian L; Scholtz, Jan-Erik; Mack, Martin G; Schmidt, Sven; Eichler, Katrin

2015-02-01

The purpose of our study was to evaluate minimally invasive sacroiliac screw fixation for treatment of posterior pelvic instability with the help of CT controlled guidewires, assess its accuracy, safety and effectiveness, and discuss potential pitfalls. 100 guidewires and hollow titan screws were inserted in 38 patients (49.6±19.5 years) suffering from 35 sacral fractures and/or 16 sacroiliac joint disruptions due to 33 (poly-)traumatic, 2 osteoporotic and 1 post-infectious conditions. The guidewire and screw positions were analyzed in multiplanar reconstructions. The mean minimal distance between guidewire and adjacent neural foramina was 4.5±2.01mm, with a distinctly higher precision in S1 than S2. Eight guidewires showed cortical contacts, resulting in a total of 2% mismatched screws with subsequent wall violation. The fracture gaps were reduced from 3.6±0.53mm to 1.2±0.54mm. During follow-up 3 cases of minor iatrogenic sacral impaction (<5mm) due to the bolting and 2 cases of screw loosening were observed. Interventional time was 84.0min with a mean of 2.63 screws per patient whilst acquiring a mean of 93.7 interventional CT-images (DLP 336.7mGycm). The treatment of posterior pelvic instability with a guidewire-based screw insertion technique under CT-imaging results in a very high accuracy and efficacy with a low complication rate. Careful attention should be drawn to radiation levels. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Liquid crystal true 3D displays for augmented reality applications

NASA Astrophysics Data System (ADS)

Li, Yan; Liu, Shuxin; Zhou, Pengcheng; Chen, Quanming; Su, Yikai

2018-02-01

Augmented reality (AR) technology, which integrates virtual computer-generated information into the real world scene, is believed to be the next-generation human-machine interface. However, most AR products adopt stereoscopic 3D display technique, which causes the accommodation-vergence conflict. To solve this problem, we have proposed two approaches. The first is a multi-planar volumetric display using fast switching polymer-stabilized liquid crystal (PSLC) films. By rapidly switching the films between scattering and transparent states while synchronizing with a high-speed projector, the 2D slices of a 3D volume could be displayed in time sequence. We delved into the research on developing high-performance PSLC films in both normal mode and reverse mode; moreover, we also realized the demonstration of four-depth AR images with correct accommodation cues. For the second approach, we realized a holographic AR display using digital blazed gratings and a 4f system to eliminate zero-order and higher-order noise. With a 4k liquid crystal on silicon device, we achieved a field of view (FOV) of 32 deg. Moreover, we designed a compact waveguidebased holographic 3D display. In the design, there are two holographic optical elements (HOEs), each of which functions as a diffractive grating and a Fresnel lens. Because of the grating effect, holographic 3D image light is coupled into and decoupled out of the waveguide by modifying incident angles. Because of the lens effect, the collimated zero order light is focused at a point, and got filtered out. The optical power of the second HOE also helps enlarge FOV.

Quantification of the uncertainty in coronary CTA plaque measurements using dynamic cardiac phantom and 3D-printed plaque models

NASA Astrophysics Data System (ADS)

Richards, Taylor; Sturgeon, Gregory M.; Ramirez-Giraldo, Juan Carlos; Rubin, Geoffrey; Segars, Paul; Samei, Ehsan

2017-03-01

The purpose of this study was to quantify the accuracy of coronary computed tomography angiography (CTA) stenosis measurements using newly developed physical coronary plaque models attached to a base dynamic cardiac phantom (Shelley Medical DHP-01). Coronary plaque models (5 mm diameter, 50% stenosis, and 32 mm long) were designed and 3D-printed with tissue equivalent materials (calcified plaque with iodine enhanced lumen). Realistic cardiac motion was achieved by fitting known cardiac motion vectors to left ventricle volume-time curves to create synchronized heart motion profiles executed by the base cardiac phantom. Realistic coronary CTA acquisition was accomplished by synthesizing corresponding ECG waveforms for gating and reconstruction purposes. All scans were acquired using a retrospective gating technique on a dual-source CT system (Siemens SOMATOM FLASH) with 75ms temporal resolution. Multi-planar reformatted images were reconstructed along vessel centerlines and the enhanced lumens were manually segmented by 5 independent operators. On average, the stenosis measurement accuracy was 0.9% positive bias for the motion free condition (0 bpm). The measurement accuracy monotonically decreased to 18.5% negative bias at 90 bpm. Contrast-tonoise (CNR), vessel circularity, and segmentation conformity also decreased monotonically with increasing heart rate. These results demonstrate successful implementation of the base cardiac phantom with 3D-printed coronary plaque models, adjustable motion profiles, and coordinated ECG waveforms. They further show the utility of the model to ascertain metrics of coronary CT accuracy and image quality under a variety of plaque, motion, and acquisition conditions.

Morphological assessment of the stylohyoid complex variations with cone beam computed tomography in a Turkish population.

PubMed

Buyuk, C; Gunduz, K; Avsever, H

2018-01-01

The aim of this investigation was to evaluate the length, thickness, sagittal and transverse angulations and the morphological variations of the stylohyoid complex (SHC), to assess their probable associations with age and gender, and to investigate the prevalence of it in a wide range of a Turkish sub-population by using cone beam computed tomography (CBCT). The CBCT images of the 1000 patients were evaluated retrospectively. The length, thickness, sagittal and transverse angulations, morphological variations and ossification degrees of SHC were evaluated on multiplanar reconstructions (MPR) adnd three-dimensional (3D) volume rendering (3DVR) images. The data were analysed statistically by using nonparametric tests, Pearson's correlation coefficient, Student's t test, c2 test and one-way ANOVA. Statistical significance was considered at p < 0.05. It was determined that 684 (34.2%) of all 2000 SHCs were elongated (> 35 mm). The mean sagittal angle value was measured to be 72.24° and the mean transverse angle value was 70.81°. Scalariform shape, elongated type and nodular calcification pattern have the highest mean age values between the morphological groups, respectively. Calcified outline was the most prevalent calcification pattern in males. There was no correlation between length and the calcification pattern groups while scalariform shape and pseudoarticular type were the longest variations. We observed that as the anterior sagittal angle gets wider, SHC tends to get longer. The most observed morphological variations were linear shape, elongated type and calcified outline pattern. Detailed studies on the classification will contribute to the literature. (Folia Morphol 2018; 77, 1: 79-89).

Complete vs partial-thickness tears of the posterior cruciate ligament: MR findings.

PubMed

Patten, R M; Richardson, M L; Zink-Brody, G; Rolfe, B A

1994-01-01

We sought to define the MRI appearance of both complete and partial-thickness tears of the posterior cruciate ligament (PCL) and to describe patterns of injury and associated MRI findings. Three radiologists retrospectively reviewed MR images and medical records on 32 patients with PCL tears (15 complete, 17 partial) and correlated MRI findings to results of clinical testing and surgery. The PCL had indistinct margins in 27 (84%) of 32 patients and was abnormally thick in 25 (78%) patients. In 31 (97%) patients, the torn PCL showed increased signal intensity on both T1- and T2-weighted pulse sequences. Although there was no statistically significant difference between patients with complete tears and those with partial tears with regard to thickness, margination, and signal intensity of the PCL, MR images in patients with complete tears were more likely to show focal areas of ligamentous discontinuity (10 of 15 cases) (p = 0.01). Associated knee injuries were seen in 21 (66%) patients and were seen more frequently in patients with complete PCL tears (p = 0.015). Bony injury (n = 11, 34%) and tears of the medial collateral ligament (n = 13, 41%) and menisci (n = 10, 31%) were common. No specific pattern of bony injury was found. Posterior cruciate ligament tears can be diagnosed readily by multiplanar MRI using both morphological and signal intensity characteristics. Although differentiation between complete and partial-thickness PCL tears by MRI criteria alone is more problematic, complete tears are more likely to show focal areas of discontinuity and partial tears are more likely to show at least some intact fibers.

Characterizing mandibular growth using three-dimensional imaging techniques and anatomic landmarks

PubMed Central

Kelly, Michael P.; Vorperian, Houri K.; Wang, Yuan; Tillman, Katelyn K.; Werner, Helen M.; Chung, Moo K.; Gentry, Lindell R.

2017-01-01

Objective To provide quantitative data on the multi-planar growth of the mandible, this study derived accurate linear and angular mandible measurements using landmarks on three dimensional (3D) mandible models. This novel method was used to quantify 3D mandibular growth and characterize the emergence of sexual dimorphism. Design Cross-sectional and longitudinal imaging data were obtained from a retrospective computed tomography (CT) database for 51 typically developing individuals between the ages of one and nineteen years. The software Analyze was used to generate 104 3DCT mandible models. Eleven landmarks placed on the models defined six linear measurements (lateral condyle, gonion, and endomolare width, ramus and mental depth, and mandible length) and three angular measurements (gonion, gnathion, and lingual). A fourth degree polynomial fit quantified growth trends, its derivative quantified growth rates, and a composite growth model determined growth types (neural/cranial and somatic/skeletal). Sex differences were assessed in four age cohorts, each spanning five years, to determine the ontogenetic pattern producing sexual dimorphism of the adult mandible. Results Mandibular growth trends and growth rates were non-uniform. In general, structures in the horizontal plane displayed predominantly neural/cranial growth types, whereas structures in the vertical plane had somatic/skeletal growth types. Significant prepubertal sex differences in the inferior aspect of the mandible dissipated when growth in males began to outpace that of females at eight to ten years of age, but sexual dimorphism re-emerged during and after puberty. Conclusions This 3D analysis of mandibular growth provides preliminary normative developmental data for clinical assessment and craniofacial growth studies. PMID:28161602

Dynamic Contrast-Enhanced Magnetic Resonance Imaging With Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid for Quantitative Assessment of Vascular Effects on Hepatocellular-Carcinoma Lesions Treated by Transarterial Chemoembolization or Radiofrequency Ablation.

PubMed

Ippolito, Davide; Trattenero, Chiara; Talei Franzesi, Cammillo; Casiraghi, Alessandra; Lombardi, Sophie; Vacirca, Francesco; Corso, Rocco; Sironi, Sandro

2016-01-01

The aim of this study was to investigate the role of dynamic contrast-enhanced magnetic resonance imaging (MRI) in evaluation of blood flow changes related to transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) procedures in patients with hepatocellular carcinoma (HCC) lesions. Fifty-four patients, with biopsy-proven HCC, who underwent TACE or RFA, were evaluated, 1 month after treatment, with upper abdominal MRI examination. Multiplanar T2-weighted, T1-weighted, and dynamic contrast-enhanced sequences were acquired. Dedicated perfusion software (T1 Perfusion Package, Viewforum; Philips Medical Systems, The Netherlands) was used to generate color permeability maps. After placing regions of interest in normal hepatic parenchyma, in successfully treated lesions, and in area of recurrence, the following perfusion parameters were calculated and statistically analyzed: relative arterial, venous, and late enhancement; maximum enhancement; maximum relative enhancement, and time to peak. Twenty-one of 54 patients had residual disease, and perfusion parameters values measured within tumor tissue were: relative arterial enhancement median, 42%; relative venous enhancement median, 69%; relative late enhancement median, 57.7%; maximum enhancement median, 749.6%; maximum relative enhancement median, 69%; time to peak median, 81.1 seconds. As for all the evaluated parameters, a significant difference (P < 0.05) was found between residual viable tumor tissue and effective treated lesions. Dynamic contrast-enhanced MRI represents a complementary noninvasive tool that may offer quantitative and qualitative information about HCC lesions treated with TACE and RFA.

Prevention of Thumb Web Space Contracture With Multiplanar External Fixation.

PubMed

Harper, Carl M; Iorio, Matthew L

2016-09-01

Thumb web space contracture following hand trauma can be disabling with numerous reconstructive procedures existing to correct the resultant deformity. Following marked soft tissue injury to the hand we utilized the Stryker Hoffmann II Micro External Fixator System to link the first and second metacarpals by a multiplanar system using 1.6 or 2.0 mm self-drilling half-pins and 3 mm carbon fiber connecting rods. This facilitated placement of the thumb in maximal palmar abduction as well as allowed adjustment of thumb position throughout the postoperative period. This technique was performed on 5 patients. Two patients were treated with a first web space external fixator for table saw injuries to the radial aspect of the hand. An additional 2 patients were treated with a first web space external fixator following metacarpophalangeal joint capsular release in the setting of thermal burns. A fifth patient underwent second ray amputation, trapeziectomy and trapezoidectomy for squamous cell carcinoma with subsequent stabilization with the external fixator. The external fixator was left in place until soft tissues were healed (average 5.5 wk). The patients were allowed to mobilize their hand in as much as the external fixator allowed, and no device-associated complications were noted. Thumb web space was preserved with passive and supple thumb circumduction and web space abduction/adduction in all patients at an average follow-up of 5 months. The average Quick Dash Score was 35±5 and the average Modern Activity Subjective Survey of 2007 was 30±8.

Data Visualization and Animation Lab (DVAL) overview

NASA Technical Reports Server (NTRS)

Stacy, Kathy; Vonofenheim, Bill

1994-01-01

The general capabilities of the Langley Research Center Data Visualization and Animation Laboratory is described. These capabilities include digital image processing, 3-D interactive computer graphics, data visualization and analysis, video-rate acquisition and processing of video images, photo-realistic modeling and animation, video report generation, and color hardcopies. A specialized video image processing system is also discussed.

Health IT and inappropriate utilization of outpatient imaging: A cross-sectional study of U.S. hospitals.

PubMed

Appari, Ajit; Johnson, M Eric; Anthony, Denise L

2018-01-01

To determine whether the use of information technology (IT), measured by Meaningful Use capability, is associated with lower rates of inappropriate utilization of imaging services in hospital outpatient settings. A retrospective cross-sectional analysis of 3332 nonfederal U.S. hospitals using data from: Hospital Compare (2011 outpatient imaging efficiency measures), HIMSS Analytics (2009 health IT), and Health Indicator Warehouse (market characteristics). Hospitals were categorized for their health IT infrastructure including EHR Stage-1 capability, and three advanced imaging functionalities/systems including integrated picture archiving and communication system, Web-based image distribution, and clinical decision support (CDS) with physician pathways. Three imaging efficiency measures suggesting inappropriate utilization during 2011 included: percentage of "combined" (with and without contrast) computed tomography (CT) studies out of all CT studies for abdomen and chest respectively, and percentage of magnetic resonance imaging (MRI) studies of lumbar spine without antecedent conservative therapy within 60days. For each measure, three separate regression models (GLM with gamma-log link function, and denominator of imaging measure as exposure) were estimated adjusting for hospital characteristics, market characteristics, and state fixed effects. Additionally, Heckman's Inverse Mills Ratio and propensity for Stage-1 EHR capability were used to account for selection bias. We find support for association of each of the four health IT capabilities with inappropriate utilization rates of one or more imaging modality. Stage-1 EHR capability is associated with lower inappropriate utilization rates for chest CT (incidence rate ratio IRR=0.72, p-value <0.01) and lumbar MRI (IRR=0.87, p-value <0.05). Integrated PACS is associated with lower inappropriate utilization rate of abdomen CT (IRR=0.84, p-value <0.05). Imaging distribution over Web capability is associated with lower inappropriate utilization rates for chest CT (IRR=0.66, p-value <0.05) and lumbar MRI (IRR=0.86, p-value <0.05). CDS with physician pathways is associated with lower inappropriate utilization rates for abdomen CT (IRR=0.87, p-value <0.01) and lumbar MRI (IRR=0.90, p-value <0.05). All other cases showed no association. The study offers mixed results. Taken together, the results suggest that the use of Stage-1 Meaningful Use capable EHR systems along with advanced imaging related functionalities could have a beneficial impact on reducing some of the inappropriate utilization of outpatient imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Multimodal quantitative phase and fluorescence imaging of cell apoptosis

NASA Astrophysics Data System (ADS)

Fu, Xinye; Zuo, Chao; Yan, Hao

2017-06-01

Fluorescence microscopy, utilizing fluorescence labeling, has the capability to observe intercellular changes which transmitted and reflected light microscopy techniques cannot resolve. However, the parts without fluorescence labeling are not imaged. Hence, the processes simultaneously happen in these parts cannot be revealed. Meanwhile, fluorescence imaging is 2D imaging where information in the depth is missing. Therefore the information in labeling parts is also not complete. On the other hand, quantitative phase imaging is capable to image cells in 3D in real time through phase calculation. However, its resolution is limited by the optical diffraction and cannot observe intercellular changes below 200 nanometers. In this work, fluorescence imaging and quantitative phase imaging are combined to build a multimodal imaging system. Such system has the capability to simultaneously observe the detailed intercellular phenomenon and 3D cell morphology. In this study the proposed multimodal imaging system is used to observe the cell behavior in the cell apoptosis. The aim is to highlight the limitations of fluorescence microscopy and to point out the advantages of multimodal quantitative phase and fluorescence imaging. The proposed multimodal quantitative phase imaging could be further applied in cell related biomedical research, such as tumor.

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors

PubMed Central

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

Purpose To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Methods Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Results Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm—56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm—68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). Conclusion MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors. PMID:26332466

Semiconductor Laser Multi-Spectral Sensing and Imaging

PubMed Central

Le, Han Q.; Wang, Yang

2010-01-01

Multi-spectral laser imaging is a technique that can offer a combination of the laser capability of accurate spectral sensing with the desirable features of passive multispectral imaging. The technique can be used for detection, discrimination, and identification of objects by their spectral signature. This article describes and reviews the development and evaluation of semiconductor multi-spectral laser imaging systems. Although the method is certainly not specific to any laser technology, the use of semiconductor lasers is significant with respect to practicality and affordability. More relevantly, semiconductor lasers have their own characteristics; they offer excellent wavelength diversity but usually with modest power. Thus, system design and engineering issues are analyzed for approaches and trade-offs that can make the best use of semiconductor laser capabilities in multispectral imaging. A few systems were developed and the technique was tested and evaluated on a variety of natural and man-made objects. It was shown capable of high spectral resolution imaging which, unlike non-imaging point sensing, allows detecting and discriminating objects of interest even without a priori spectroscopic knowledge of the targets. Examples include material and chemical discrimination. It was also shown capable of dealing with the complexity of interpreting diffuse scattered spectral images and produced results that could otherwise be ambiguous with conventional imaging. Examples with glucose and spectral imaging of drug pills were discussed. Lastly, the technique was shown with conventional laser spectroscopy such as wavelength modulation spectroscopy to image a gas (CO). These results suggest the versatility and power of multi-spectral laser imaging, which can be practical with the use of semiconductor lasers. PMID:22315555

Semiconductor laser multi-spectral sensing and imaging.

PubMed

Le, Han Q; Wang, Yang

2010-01-01

Multi-spectral laser imaging is a technique that can offer a combination of the laser capability of accurate spectral sensing with the desirable features of passive multispectral imaging. The technique can be used for detection, discrimination, and identification of objects by their spectral signature. This article describes and reviews the development and evaluation of semiconductor multi-spectral laser imaging systems. Although the method is certainly not specific to any laser technology, the use of semiconductor lasers is significant with respect to practicality and affordability. More relevantly, semiconductor lasers have their own characteristics; they offer excellent wavelength diversity but usually with modest power. Thus, system design and engineering issues are analyzed for approaches and trade-offs that can make the best use of semiconductor laser capabilities in multispectral imaging. A few systems were developed and the technique was tested and evaluated on a variety of natural and man-made objects. It was shown capable of high spectral resolution imaging which, unlike non-imaging point sensing, allows detecting and discriminating objects of interest even without a priori spectroscopic knowledge of the targets. Examples include material and chemical discrimination. It was also shown capable of dealing with the complexity of interpreting diffuse scattered spectral images and produced results that could otherwise be ambiguous with conventional imaging. Examples with glucose and spectral imaging of drug pills were discussed. Lastly, the technique was shown with conventional laser spectroscopy such as wavelength modulation spectroscopy to image a gas (CO). These results suggest the versatility and power of multi-spectral laser imaging, which can be practical with the use of semiconductor lasers.

4-mm-diameter three-dimensional imaging endoscope with steerable camera for minimally invasive surgery (3-D-MARVEL).

PubMed

Bae, Sam Y; Korniski, Ronald J; Shearn, Michael; Manohara, Harish M; Shahinian, Hrayr

2017-01-01

High-resolution three-dimensional (3-D) imaging (stereo imaging) by endoscopes in minimally invasive surgery, especially in space-constrained applications such as brain surgery, is one of the most desired capabilities. Such capability exists at larger than 4-mm overall diameters. We report the development of a stereo imaging endoscope of 4-mm maximum diameter, called Multiangle, Rear-Viewing Endoscopic Tool (MARVEL) that uses a single-lens system with complementary multibandpass filter (CMBF) technology to achieve 3-D imaging. In addition, the system is endowed with the capability to pan from side-to-side over an angle of [Formula: see text], which is another unique aspect of MARVEL for such a class of endoscopes. The design and construction of a single-lens, CMBF aperture camera with integrated illumination to generate 3-D images, and the actuation mechanism built into it is summarized.

Interactive degraded document enhancement and ground truth generation

NASA Astrophysics Data System (ADS)

Bal, G.; Agam, G.; Frieder, O.; Frieder, G.

2008-01-01

Degraded documents are frequently obtained in various situations. Examples of degraded document collections include historical document depositories, document obtained in legal and security investigations, and legal and medical archives. Degraded document images are hard to to read and are hard to analyze using computerized techniques. There is hence a need for systems that are capable of enhancing such images. We describe a language-independent semi-automated system for enhancing degraded document images that is capable of exploiting inter- and intra-document coherence. The system is capable of processing document images with high levels of degradations and can be used for ground truthing of degraded document images. Ground truthing of degraded document images is extremely important in several aspects: it enables quantitative performance measurements of enhancement systems and facilitates model estimation that can be used to improve performance. Performance evaluation is provided using the historical Frieder diaries collection.1

Acoustically modulated magnetic resonance imaging of gas-filled protein nanostructures

NASA Astrophysics Data System (ADS)

Lu, George J.; Farhadi, Arash; Szablowski, Jerzy O.; Lee-Gosselin, Audrey; Barnes, Samuel R.; Lakshmanan, Anupama; Bourdeau, Raymond W.; Shapiro, Mikhail G.

2018-05-01

Non-invasive biological imaging requires materials capable of interacting with deeply penetrant forms of energy such as magnetic fields and sound waves. Here, we show that gas vesicles (GVs), a unique class of gas-filled protein nanostructures with differential magnetic susceptibility relative to water, can produce robust contrast in magnetic resonance imaging (MRI) at sub-nanomolar concentrations, and that this contrast can be inactivated with ultrasound in situ to enable background-free imaging. We demonstrate this capability in vitro, in cells expressing these nanostructures as genetically encoded reporters, and in three model in vivo scenarios. Genetic variants of GVs, differing in their magnetic or mechanical phenotypes, allow multiplexed imaging using parametric MRI and differential acoustic sensitivity. Additionally, clustering-induced changes in MRI contrast enable the design of dynamic molecular sensors. By coupling the complementary physics of MRI and ultrasound, this nanomaterial gives rise to a distinct modality for molecular imaging with unique advantages and capabilities.

A bidirectional ACR-NEMA interface between the VA's DHCP Integrated Imaging System and the Siemens-Loral PACS.

PubMed Central

Kuzmak, P. M.; Dayhoff, R. E.

1992-01-01

There is a wide range of requirements for digital hospital imaging systems. Radiology needs very high resolution black and white images. Other diagnostic disciplines need high resolution color imaging capabilities. Images need to be displayed in many locations throughout the hospital. Different imaging systems within a hospital need to cooperate in order to show the whole picture. At the Baltimore VA Medical Center, the DHCP Integrated Imaging System and a commercial Picture Archiving and Communication System (PACS) work in concert to provide a wide-range of departmental and hospital-wide imaging capabilities. An interface between the DHCP and the Siemens-Loral PACS systems enables patient text and image data to be passed between the two systems. The interface uses ACR-NEMA 2.0 Standard messages extended with shadow groups based on draft ACR-NEMA 3.0 prototypes. A Novell file server, accessible to both systems via Ethernet, is used to communicate all the messages. Patient identification information, orders, ADT, procedure status, changes, patient reports, and images are sent between the two systems across the interface. The systems together provide an extensive set of imaging capabilities for both the specialist and the general practitioner. PMID:1482906

A bidirectional ACR-NEMA interface between the VA's DHCP Integrated Imaging System and the Siemens-Loral PACS.

PubMed

Kuzmak, P M; Dayhoff, R E

1992-01-01

There is a wide range of requirements for digital hospital imaging systems. Radiology needs very high resolution black and white images. Other diagnostic disciplines need high resolution color imaging capabilities. Images need to be displayed in many locations throughout the hospital. Different imaging systems within a hospital need to cooperate in order to show the whole picture. At the Baltimore VA Medical Center, the DHCP Integrated Imaging System and a commercial Picture Archiving and Communication System (PACS) work in concert to provide a wide-range of departmental and hospital-wide imaging capabilities. An interface between the DHCP and the Siemens-Loral PACS systems enables patient text and image data to be passed between the two systems. The interface uses ACR-NEMA 2.0 Standard messages extended with shadow groups based on draft ACR-NEMA 3.0 prototypes. A Novell file server, accessible to both systems via Ethernet, is used to communicate all the messages. Patient identification information, orders, ADT, procedure status, changes, patient reports, and images are sent between the two systems across the interface. The systems together provide an extensive set of imaging capabilities for both the specialist and the general practitioner.

Accuracy of determining preoperative cancer extent measured by automated breast ultrasonography.

PubMed

Tozaki, Mitsuhiro; Fukuma, Eisuke

2010-12-01

The aim of this study was to determine the accuracy of measuring preoperative cancer extent using automated breast ultrasonography (US). This retrospective study consisted of 40 patients with histopathologically confirmed breast cancer. All of the patients underwent automated breast US (ABVS; Siemens Medical Solutions, Mountain View, CA, USA) on the day before the surgery. The sizes of the lesions on US were measured on coronal multiplanar reconstruction images using the ABVS workstation. Histopathological measurement of tumor size included not only the invasive foci but also any in situ component and was used as the gold standard. The discrepancy of the tumor extent between automated breast US and the histological examination was calculated. Automated breast US enabled visualization of the breast carcinomas in all patients. The mean size of the lesions on US was 12 mm (range 4-62 mm). The histopathological diagnosis was ductal carcinoma in situ (DCIS) in seven patients and invasive ductal carcinoma in 33 patients (18 without an intraductal component, 15 with an intraductal component). Lesions ranged in diameter from 4 to 65 mm (mean 16 mm). The accuracy of determination of the tumor extent with a deviation in length of <2 cm was 98% (39/40). Automated breast US is thought to be useful for evaluating tumor extent preoperatively.

Multi-detector CT features of acute intestinal ischemia and their prognostic correlations.

PubMed

Moschetta, Marco; Telegrafo, Michele; Rella, Leonarda; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe

2014-05-28

Acute intestinal ischemia is an abdominal emergency occurring in nearly 1% of patients presenting with acute abdomen. The causes can be occlusive or non occlusive. Early diagnosis is important to improve survival rates. In most cases of late or missed diagnosis, the mortality rate from intestinal infarction is very high, with a reported value ranging from 60% to 90%. Multi-detector computed tomography (MDCT) is a fundamental imaging technique that must be promptly performed in all patients with suspected bowel ischemia. Thanks to the new dedicated reconstruction program, its diagnostic potential is much improved compared to the past and currently it is superior to that of any other noninvasive technique. The increased spatial and temporal resolution, high-quality multi-planar reconstructions, maximum intensity projections, vessel probe, surface-shaded volume rending and tissue transition projections make MDCT the gold standard for the diagnosis of intestinal ischemia, with reported sensitivity, specificity, positive and negative predictive values of 64%-93%, 92%-100%, 90%-100% and 94%-98%, respectively. MDCT contributes to appropriate treatment planning and provides important prognostic information thanks to its ability to define the nature and extent of the disease. The purpose of this review is to examine the diagnostic and prognostic role of MDCT in bowel ischemia with special regard to the state of art new reconstruction software.

Regional variations in the density and arrangement of elastic fibres in the anulus fibrosus of the human lumbar disc

PubMed Central

Smith, Lachlan J; Fazzalari, Nicola L

2006-01-01

Elastic fibres are critical components of the extracellular matrix in dynamic biological structures that undergo extension and recoil. Their presence has been demonstrated in the anulus fibrosus of the human lumbar intervertebral disc; however, a detailed regional analysis of their density and arrangement has not been undertaken, limiting our understanding of their structural and functional roles. In this investigation we have quantitatively described regional variations in elastic fibre density in the anulus fibrosus of the human L3–L4 intervertebral disc using histochemistry and light microscopy. Additionally, a multiplanar comparison of patterns of elastic fibre distribution in the intralamellar and interlamellar zones was undertaken. Novel imaging techniques were developed to facilitate the visualization of elastic fibres otherwise masked by dense surrounding matrix. Elastic fibre density was found to be significantly higher in the lamellae of the posterolateral region of the anulus than the anterolateral, and significantly higher in the outer regions than the inner, suggesting that elastic fibre density in each region of the anulus is commensurate with the magnitude of the tensile deformations experienced in bending and torsion. Elastic fibre arrangments in intralamellar and interlamellar zones were shown to be architecturally distinct, suggesting that they perform multiple functional roles within the anulus matrix structural hierarchy. PMID:16928204

[Development of a System to Use Patient's Information Which is Required at the Radiological Department].

PubMed

Satoh, Akihiro

2016-04-01

The purpose of this study is to develop a new system to get and share some data of a patient which are required for a radiological examination not using an electronic medical chart or a radiological information system (RIS), and also to demonstrate that this system is operated on cloud technology. I used Java Enterprise Edition (Java EE) as a programing language and MySQL as a server software, and I used two laptops as hardware for client computer and server computer. For cloud computing, I hired a server of Google App Engine for Java (GAE). As a result, I could get some data of the patient required at his/her examination instantly using this system. This system also helps to improve the efficiency of examination. For example, it has been useful when I want to decide radiographic condition or to create CT images such as multi-planar reconstruction (MPR) or volume rendering (VR). When it comes to cloud computing, the GAE was used experimentally due to some legal restrictions. From the above points it is clear that this system has played an important role in radiological examinations, but there has been still few things which I have to resolve for cloud computing.

Appropriate hinge position for prevention of unstable lateral hinge fracture in open wedge high tibial osteotomy.

PubMed

Nakamura, R; Komatsu, N; Fujita, K; Kuroda, K; Takahashi, M; Omi, R; Katsuki, Y; Tsuchiya, H

2017-10-01

Open wedge high tibial osteotomy (OWHTO) for medial-compartment osteoarthritis of the knee can be complicated by intra-operative lateral hinge fracture (LHF). We aimed to establish the relationship between hinge position and fracture types, and suggest an appropriate hinge position to reduce the risk of this complication. Consecutive patients undergoing OWHTO were evaluated on coronal multiplanar reconstruction CT images. Hinge positions were divided into five zones in our new classification, by their relationship to the proximal tibiofibular joint (PTFJ). Fractures were classified into types I, II, and III according to the Takeuchi classification. Among 111 patients undergoing OWHTOs, 22 sustained lateral hinge fractures. Of the 89 patients without fractures, 70 had hinges in the zone within the PTFJ and lateral to the medial margin of the PTFJ (zone WL), just above the PTFJ. Among the five zones, the relative risk of unstable fracture was significantly lower in zone WL (relative risk 0.24, confidence interval 0.17 to 0.34). Zone WL appears to offer the safest position for the placement of the osteotomy hinge when trying to avoid a fracture at the osteotomy site. Cite this article: Bone Joint J 2017;99B10:1313-18. ©2017 The British Editorial Society of Bone & Joint Surgery.

Angularly-selective transmission imaging in a scanning electron microscope.

PubMed

Holm, Jason; Keller, Robert R

2016-08-01

This work presents recent advances in transmission scanning electron microscopy (t-SEM) imaging control capabilities. A modular aperture system and a cantilever-style sample holder that enable comprehensive angular selectivity of forward-scattered electrons are described. When combined with a commercially available solid-state transmission detector having only basic bright-field and dark-field imaging capabilities, the advances described here enable numerous transmission imaging modes. Several examples are provided that demonstrate how contrast arising from diffraction to mass-thickness can be obtained. Unanticipated image contrast at some imaging conditions is also observed and addressed. Published by Elsevier B.V.

Real-time quantitative fluorescence imaging using a single snapshot optical properties technique for neurosurgical guidance

NASA Astrophysics Data System (ADS)

Valdes, Pablo A.; Angelo, Joseph; Gioux, Sylvain

2015-03-01

Fluorescence imaging has shown promise as an adjunct to improve the extent of resection in neurosurgery and oncologic surgery. Nevertheless, current fluorescence imaging techniques do not account for the heterogeneous attenuation effects of tissue optical properties. In this work, we present a novel imaging system that performs real time quantitative fluorescence imaging using Single Snapshot Optical Properties (SSOP) imaging. We developed the technique and performed initial phantom studies to validate the quantitative capabilities of the system for intraoperative feasibility. Overall, this work introduces a novel real-time quantitative fluorescence imaging method capable of being used intraoperatively for neurosurgical guidance.

Effect of halo-vest components on stabilizing the injured cervical spine.

PubMed

Ivancic, Paul C; Beauchman, Naseem N; Tweardy, Lisa

2009-01-15

An in vitro biomechanical study. The objectives were to develop a new biofidelic skull-neck-thorax model capable of quantifying motion patterns of the cervical spine in the presence of a halo-vest; to investigate the effects of vest loosening, superstructure loosening, and removal of the posterior uprights; and to evaluate the ability of the halo-vest to stabilize the neck within physiological motion limits. Previous clinical and biomechanical studies have investigated neck motion with the halo-vest only in the sagittal plane or only at the injured spinal level. No previous studies have quantified three-dimensional intervertebral motion patterns throughout the injured cervical spine stabilized with the halo-vest or studied the effect of halo-vest components on these motions. The halo-vest was applied to the skull-neck-thorax model. Six osteoligamentous whole cervical spine specimens (occiput through T1 vertebra) were used that had sustained multiplanar ligamentous injuries at C3/4 through C7-T1 during a previous protocol. Flexibility tests were performed with normal halo-vest application, loose vest, loose superstructure, and following removal of the posterior uprights. Average total range of motion for each experimental condition was statistically compared (P < 0.05) with the physiologic rotation limit for each spinal level. Cervical spine snaking was observed in both the sagittal and frontal planes. The halo-vest, applied normally, generally limited average spinal motions to within average physiological limits. No significant increases in average spinal motions above physiologic were observed due to loose vest, loose superstructure, or removal of the posterior uprights. However, a trend toward increased motion at C6/7 in lateral bending was observed due to loose superstructure. The halo-vest, applied normally, effectively immobilized the cervical spine. Sagittal or frontal plane snaking of the cervical spine due to the halo-vest may reduce its immobilization capability at the upper cervical spine and cervicothoracic junction.

High resolution imaging and wavefront aberration correction in plenoptic systems.

PubMed

Trujillo-Sevilla, J M; Rodríguez-Ramos, L F; Montilla, I; Rodríguez-Ramos, J M

2014-09-01

Plenoptic imaging systems are becoming more common since they provide capabilities unattainable in conventional imaging systems, but one of their main limitations is the poor bidimensional resolution. Combining the wavefront phase measurement and the plenoptic image deconvolution, we propose a system capable of improving the resolution when a wavefront aberration is present and the image is blurred. In this work, a plenoptic system is simulated using Fourier optics, and the results show that an improved resolution is achieved, even in the presence of strong wavefront aberrations.

Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS): Imaging and Tracking Capability

NASA Technical Reports Server (NTRS)

Zhou, D. K.; Larar, A. M.; Liu, Xu; Reisse, R. A.; Smith, W. L.; Revercomb, H. E.; Bingham, G. E.; Zollinger, L. J.; Tansock, J. J.; Huppi, Ronald J.

2007-01-01

The geosynchronous-imaging Fourier transform spectrometer (GIFTS) engineering demonstration unit (EDU) is an imaging infrared spectrometer designed for atmospheric soundings. It measures the infrared spectrum in two spectral bands (14.6 to 8.8 microns, 6.0 to 4.4 microns) using two 128 128 detector arrays with a spectral resolution of 0.57/cm with a scan duration of approx. 11 seconds. From a geosynchronous orbit, the instrument will have the capability of taking successive measurements of such data to scan desired regions of the globe, from which atmospheric status, cloud parameters, wind field profiles, and other derived products can be retrieved. The GIFTS EDU provides a flexible and accurate testbed for the new challenges of the emerging hyperspectral era. The EDU ground-based measurement experiment, held in Logan, Utah during September 2006, demonstrated its extensive capabilities and potential for geosynchronous and other applications (e.g., Earth observing environmental measurements). This paper addresses the experiment objectives and overall performance of the sensor system with a focus on the GIFTS EDU imaging capability and proof of the GIFTS measurement concept.

Integrated one- and two-photon scanned oblique plane illumination (SOPi) microscopy for rapid volumetric imaging

NASA Astrophysics Data System (ADS)

Kumar, Manish; Kishore, Sandeep; Nasenbeny, Jordan; McLean, David L.; Kozorovitskiy, Yevgenia

2018-05-01

Versatile, sterically accessible imaging systems capable of in vivo rapid volumetric functional and structural imaging deep in the brain continue to be a limiting factor in neuroscience research. Towards overcoming this obstacle, we present integrated one- and two-photon scanned oblique plane illumination (SOPi) microscopy which uses a single front-facing microscope objective to provide light-sheet scanning based rapid volumetric imaging capability at subcellular resolution. Our planar scan-mirror based optimized light-sheet architecture allows for non-distorted scanning of volume samples, simplifying accurate reconstruction of the imaged volume. Integration of both one-photon (1P) and two-photon (2P) light-sheet microscopy in the same system allows for easy selection between rapid volumetric imaging and higher resolution imaging in scattering media. Using SOPi, we demonstrate deep, large volume imaging capability inside scattering mouse brain sections and rapid imaging speeds up to 10 volumes per second in zebrafish larvae expressing genetically encoded fluorescent proteins GFP or GCaMP6s. SOPi flexibility and steric access makes it adaptable for numerous imaging applications and broadly compatible with orthogonal techniques for actuating or interrogating neuronal structure and activity.

Integrated one- and two-photon scanned oblique plane illumination (SOPi) microscopy for rapid volumetric imaging.

PubMed

Kumar, Manish; Kishore, Sandeep; Nasenbeny, Jordan; McLean, David L; Kozorovitskiy, Yevgenia

2018-05-14

Versatile, sterically accessible imaging systems capable of in vivo rapid volumetric functional and structural imaging deep in the brain continue to be a limiting factor in neuroscience research. Towards overcoming this obstacle, we present integrated one- and two-photon scanned oblique plane illumination (SOPi, /sōpī/) microscopy which uses a single front-facing microscope objective to provide light-sheet scanning based rapid volumetric imaging capability at subcellular resolution. Our planar scan-mirror based optimized light-sheet architecture allows for non-distorted scanning of volume samples, simplifying accurate reconstruction of the imaged volume. Integration of both one-photon (1P) and two-photon (2P) light-sheet microscopy in the same system allows for easy selection between rapid volumetric imaging and higher resolution imaging in scattering media. Using SOPi, we demonstrate deep, large volume imaging capability inside scattering mouse brain sections and rapid imaging speeds up to 10 volumes per second in zebrafish larvae expressing genetically encoded fluorescent proteins GFP or GCaMP6s. SOPi's flexibility and steric access makes it adaptable for numerous imaging applications and broadly compatible with orthogonal techniques for actuating or interrogating neuronal structure and activity.

Ultra-sensitive fluorescent imaging-biosensing using biological photonic crystals

NASA Astrophysics Data System (ADS)

Squire, Kenny; Kong, Xianming; Wu, Bo; Rorrer, Gregory; Wang, Alan X.

2018-02-01

Optical biosensing is a growing area of research known for its low limits of detection. Among optical sensing techniques, fluorescence detection is among the most established and prevalent. Fluorescence imaging is an optical biosensing modality that exploits the sensitivity of fluorescence in an easy-to-use process. Fluorescence imaging allows a user to place a sample on a sensor and use an imager, such as a camera, to collect the results. The image can then be processed to determine the presence of the analyte. Fluorescence imaging is appealing because it can be performed with as little as a light source, a camera and a data processor thus being ideal for nontrained personnel without any expensive equipment. Fluorescence imaging sensors generally employ an immunoassay procedure to selectively trap analytes such as antigens or antibodies. When the analyte is present, the sensor fluoresces thus transducing the chemical reaction into an optical signal capable of imaging. Enhancement of this fluorescence leads to an enhancement in the detection capabilities of the sensor. Diatoms are unicellular algae with a biosilica shell called a frustule. The frustule is porous with periodic nanopores making them biological photonic crystals. Additionally, the porous nature of the frustule allows for large surface area capable of multiple analyte binding sites. In this paper, we fabricate a diatom based ultra-sensitive fluorescence imaging biosensor capable of detecting the antibody mouse immunoglobulin down to a concentration of 1 nM. The measured signal has an enhancement of 6× when compared to sensors fabricated without diatoms.

Molecular imaging of melanin distribution in vivo and quantitative differential diagnosis of human pigmented lesions using label-free harmonic generation biopsy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sun, Chi-Kuang; Wei, Ming-Liang; Su, Yu-Hsiang; Weng, Wei-Hung; Liao, Yi-Hua

2017-02-01

Harmonic generation microscopy is a noninvasive repetitive imaging technique that provides real-time 3D microscopic images of human skin with a sub-femtoliter resolution and high penetration down to the reticular dermis. In this talk, we show that with a strong resonance effect, the third-harmonic-generation (THG) modality provides enhanced contrast on melanin and allows not only differential diagnosis of various pigmented skin lesions but also quantitative imaging for longterm tracking. This unique capability makes THG microscopy the only label-free technique capable of identifying the active melanocytes in human skin and to image their different dendriticity patterns. In this talk, we will review our recent efforts to in vivo image melanin distribution and quantitatively diagnose pigmented skin lesions using label-free harmonic generation biopsy. This talk will first cover the spectroscopic study on the melanin enhanced THG effect in human cells and the calibration strategy inside human skin for quantitative imaging. We will then review our recent clinical trials including: differential diagnosis capability study on pigmented skin tumors; as well as quantitative virtual biopsy study on pre- and post- treatment evaluation on melasma and solar lentigo. Our study indicates the unmatched capability of harmonic generation microscopy to perform virtual biopsy for noninvasive histopathological diagnosis of various pigmented skin tumors, as well as its unsurpassed capability to noninvasively reveal the pathological origin of different hyperpigmentary diseases on human face as well as to monitor the efficacy of laser depigmentation treatments. This work is sponsored by National Health Research Institutes.

Validation Test Report for the Automated Optical Processing System (AOPS) Version 4.12

DTIC Science & Technology

2015-09-03

the Geostationary Ocean Color Imager (GOCI) sensor, aboard the Communication Ocean and Meteorological Satellite (COMS) satellite. Additionally, this...this capability works in conjunction with AOPS • Improvements to the AOPS mosaicking capability • Prepare the NRT Geostationary Ocean Color Imager...Warfare (EXW) Geostationary Ocean Color Imager (GOCI) Gulf of Mexico (GOM) Hierarchical Data Format (HDF) Integrated Data Processing System (IDPS

Non-Contact Optical Ultrasound Concept for Biomedical Imaging

DTIC Science & Technology

2016-11-03

Non -Contact Optical Ultrasound Concept for Biomedical Imaging Robert Haupt1, Charles Wynn1, Jonathan Fincke2, Shawn Zhang2, Brian Anthony2...results. Lastly, we present imaging capabilities using a non -contact laser ultrasound proof-of-concept system. Two and three dimensional time... non -contact, standoff optical ultrasound has the potential to provide a fixed reference measurement capability that minimizes operator variability as

Using superconducting undulator for enhanced imaging capabilities of MaRIE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yampolsky, Nikolai

MaRIE x-ray free electron laser (FEL) is envisioned to deliver a burst of closely spaced in time pulses for enabling the capability of studying the dynamic processes in a sample. MaRIE capability can be largely enhanced using the superconducting undulator, which has the capability of doubling its period. This technology will allow reaching the photon energy as low as ~200-500 eV. As a result, the MaRIE facility will have a broader photon energy range enabling a larger variety of experiments. The soft x-ray capability is more likely to achieve the 3D imaging of dynamic processes in noncrystal materials than themore » hard x-ray capability alone.« less

Imaging and Analytics: The changing face of Medical Imaging

NASA Astrophysics Data System (ADS)

Foo, Thomas

There have been significant technological advances in imaging capability over the past 40 years. Medical imaging capabilities have developed rapidly, along with technology development in computational processing speed and miniaturization. Moving to all-digital, the number of images that are acquired in a routine clinical examination has increased dramatically from under 50 images in the early days of CT and MRI to more than 500-1000 images today. The staggering number of images that are routinely acquired poses significant challenges for clinicians to interpret the data and to correctly identify the clinical problem. Although the time provided to render a clinical finding has not substantially changed, the amount of data available for interpretation has grown exponentially. In addition, the image quality (spatial resolution) and information content (physiologically-dependent image contrast) has also increased significantly with advances in medical imaging technology. On its current trajectory, medical imaging in the traditional sense is unsustainable. To assist in filtering and extracting the most relevant data elements from medical imaging, image analytics will have a much larger role. Automated image segmentation, generation of parametric image maps, and clinical decision support tools will be needed and developed apace to allow the clinician to manage, extract and utilize only the information that will help improve diagnostic accuracy and sensitivity. As medical imaging devices continue to improve in spatial resolution, functional and anatomical information content, image/data analytics will be more ubiquitous and integral to medical imaging capability.

High performance thermal imaging for the 21st century

NASA Astrophysics Data System (ADS)

Clarke, David J.; Knowles, Peter

2003-01-01

In recent years IR detector technology has developed from early short linear arrays. Such devices require high performance signal processing electronics to meet today's thermal imaging requirements for military and para-military applications. This paper describes BAE SYSTEMS Avionics Group's Sensor Integrated Modular Architecture thermal imager which has been developed alongside the group's Eagle 640×512 arrays to provide high performance imaging capability. The electronics architecture also supprots High Definition TV format 2D arrays for future growth capability.

Results from Automated Cloud and Dust Devil Detection Onboard the MER

NASA Technical Reports Server (NTRS)

Chien, Steve; Castano, Rebecca; Bornstein, Benjamin; Fukunaga, Alex; Castano, Andres; Biesiadecki, Jeffrey; Greeley, Ron; Whelley, Patrick; Lemmon, Mark

2008-01-01

We describe a new capability to automatically detect dust devils and clouds in imagery onboard rovers, enabling downlink of just the images with the targets or only portions of the images containing the targets. Previously, the MER rovers conducted campaigns to image dust devils and clouds by commanding a set of images be collected at fixed times and downloading the entire image set. By increasing the efficiency of the campaigns, more campaigns can be executed. Software for these new capabilities was developed, tested, integrated, uploaded, and operationally checked out on both rovers as part of the R9.2 software upgrade. In April 2007 on Sol 1147 a dust devil was automatically detected onboard the Spirit rover for the first time. We discuss the operational usage of the capability and present initial dust devil results showing how this preliminary application has demonstrated the feasibility and potential benefits of the approach.

Evaluation of pharyngeal space and its correlation with mandible and hyoid bone in patients with different skeletal classes and facial types.

PubMed

Nejaim, Yuri; Aps, Johan K M; Groppo, Francisco Carlos; Haiter Neto, Francisco

2018-06-01

The purpose of this article was to evaluate the pharyngeal space volume, and the size and shape of the mandible and the hyoid bone, as well as their relationships, in patients with different facial types and skeletal classes. Furthermore, we estimated the volume of the pharyngeal space with a formula using only linear measurements. A total of 161 i-CAT Next Generation (Imaging Sciences International, Hatfield, Pa) cone-beam computed tomography images (80 men, 81 women; ages, 21-58 years; mean age, 27 years) were retrospectively studied. Skeletal class and facial type were determined for each patient from multiplanar reconstructions using the NemoCeph software (Nemotec, Madrid, Spain). Linear and angular measurements were performed using 3D imaging software (version 3.4.3; Carestream Health, Rochester, NY), and volumetric analysis of the pharyngeal space was carried out with ITK-SNAP (version 2.4.0; Cognitica, Philadelphia, Pa) segmentation software. For the statistics, analysis of variance and the Tukey test with a significance level of 0.05, Pearson correlation, and linear regression were used. The pharyngeal space volume, when correlated with mandible and hyoid bone linear and angular measurements, showed significant correlations with skeletal class or facial type. The linear regression performed to estimate the volume of the pharyngeal space showed an R of 0.92 and an adjusted R 2 of 0.8362. There were significant correlations between pharyngeal space volume, and the mandible and hyoid bone measurements, suggesting that the stomatognathic system should be evaluated in an integral and nonindividualized way. Furthermore, it was possible to develop a linear regression model, resulting in a useful formula for estimating the volume of the pharyngeal space. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Comparison of Post-Processing Techniques for the Detection of Perfusion Defects by Cardiac Computed Tomography in Patients Presenting with Acute ST Segment Elevation Myocardial Infarction

PubMed Central

Rogers, Ian S.; Cury, Ricardo C.; Blankstein, Ron; Shapiro, Michael D.; Nieman, Koen; Hoffmann, Udo; Brady, Thomas J.; Abbara, Suhny

2010-01-01

Background Despite rapid advances in cardiac computed tomography (CT), a strategy for optimal visualization of perfusion abnormalities on CT has yet to be validated. Objective To evaluate the performance of several post-processing techniques of source data sets to detect and characterize perfusion defects in acute myocardial infarctions with cardiac CT. Methods Twenty-one subjects (18 men; 60 ± 13 years) that were successfully treated with percutaneous coronary intervention for ST-segment myocardial infarction underwent 64-slice cardiac CT and 1.5 Tesla cardiac MRI scans following revascularization. Delayed enhancement MRI images were analyzed to identify the location of infarcted myocardium. Contiguous short axis images of the left ventricular myocardium were created from the CT source images using 0.75mm multiplanar reconstruction (MPR), 5mm MPR, 5mm maximal intensity projection (MIP), and 5mm minimum intensity projection (MinIP) techniques. Segments already confirmed to contain infarction by MRI were then evaluated qualitatively and quantitatively with CT. Results Overall, 143 myocardial segments were analyzed. On qualitative analysis, the MinIP and thick MPR techniques had greater visibility and definition than the thin MPR and MIP techniques (p < 0.001). On quantitative analysis, the absolute difference in Hounsfield Unit (HU) attenuation between normal and infarcted segments was significantly greater for the MinIP (65.4 HU) and thin MPR (61.2 HU) techniques. However, the relative difference in HU attenuation was significantly greatest for the MinIP technique alone (95%, p < 0.001). Contrast to noise was greatest for the MinIP (4.2) and thick MPR (4.1) techniques (p < 0.001). Conclusion The results of our current investigation found that MinIP and thick MPR detected infarcted myocardium with greater visibility and definition than MIP and thin MPR. PMID:20579617

Visual pattern image sequence coding

NASA Technical Reports Server (NTRS)

Silsbee, Peter; Bovik, Alan C.; Chen, Dapang

1990-01-01

The visual pattern image coding (VPIC) configurable digital image-coding process is capable of coding with visual fidelity comparable to the best available techniques, at compressions which (at 30-40:1) exceed all other technologies. These capabilities are associated with unprecedented coding efficiencies; coding and decoding operations are entirely linear with respect to image size and entail a complexity that is 1-2 orders of magnitude faster than any previous high-compression technique. The visual pattern image sequence coding to which attention is presently given exploits all the advantages of the static VPIC in the reduction of information from an additional, temporal dimension, to achieve unprecedented image sequence coding performance.

Quantitative imaging of the human upper airway: instrument design and clinical studies

NASA Astrophysics Data System (ADS)

Leigh, M. S.; Armstrong, J. J.; Paduch, A.; Sampson, D. D.; Walsh, J. H.; Hillman, D. R.; Eastwood, P. R.

2006-08-01

Imaging of the human upper airway is widely used in medicine, in both clinical practice and research. Common imaging modalities include video endoscopy, X-ray CT, and MRI. However, no current modality is both quantitative and safe to use for extended periods of time. Such a capability would be particularly valuable for sleep research, which is inherently reliant on long observation sessions. We have developed an instrument capable of quantitative imaging of the human upper airway, based on endoscopic optical coherence tomography. There are no dose limits for optical techniques, and the minimally invasive imaging probe is safe for use in overnight studies. We report on the design of the instrument and its use in preliminary clinical studies, and we present results from a range of initial experiments. The experiments show that the instrument is capable of imaging during sleep, and that it can record dynamic changes in airway size and shape. This information is useful for research into sleep disorders, and potentially for clinical diagnosis and therapies.

X ray sensitive area detection device

NASA Technical Reports Server (NTRS)

Carter, Daniel C. (Inventor); Witherow, William K. (Inventor); Pusey, Marc L. (Inventor); Yost, Vaughn H. (Inventor)

1990-01-01

A radiation sensitive area detection device is disclosed which comprises a phosphor-containing film capable of receiving and storing an image formed by a pattern of incoming x rays, UV, or other radiation falling on the film. The device is capable of fluorescing in response to stimulation by a light source in a manner directly proportional to the stored radiation pattern. The device includes: (1) a light source capable of projecting light or other appropriate electromagnetic wave on the film so as to cause it to fluoresce; (2) a means to focus the fluoresced light coming from the phosphor-containing film after light stimulation; and (3) at least one charged coupled detector or other detecting element capable of receiving and digitizing the pattern of fluoresced light coming from the phosphor-containing film. The device will be able to generate superior x ray images of high resolution from a crystal or other sample and will be particularly advantageous in that instantaneous near-real-time images of rapidly deteriorating samples can be obtained. Furthermore, the device can be made compact and sturdy, thus capable of carrying out x ray or other radiation imaging under a variety of conditions, including those experienced in space.

Laser interference fringe tomography: a novel 3D imaging technique for pathology

NASA Astrophysics Data System (ADS)

Kazemzadeh, Farnoud; Haylock, Thomas M.; Chifman, Lev M.; Hajian, Arsen R.; Behr, Bradford B.; Cenko, Andrew T.; Meade, Jeff T.; Hendrikse, Jan

2011-03-01

Laser interference fringe tomography (LIFT) is within the class of optical imaging devices designed for in vivo and ex vivo medical imaging applications. LIFT is a very simple and cost-effective three-dimensional imaging device with performance rivaling some of the leading three-dimensional imaging devices used for histology. Like optical coherence tomography (OCT), it measures the reflectivity as a function of depth within a sample and is capable of producing three-dimensional images from optically scattering media. LIFT has the potential capability to produce high spectral resolution, full-color images. The optical design of LIFT along with the planned iterations for improvements and miniaturization are presented and discussed in addition to the theoretical concepts and preliminary imaging results of the device.

High Contrast Imaging with NICMOS - I: Teaching an Old Dog New Tricks with Coronagraphic Polarimetry

NASA Astrophysics Data System (ADS)

Schneider, G.; Hines, D. C.

2007-06-01

HST's Near Infrared Camera and Multi-Object Spectrometer (NICMOS), with its highly stable point spread function, very high imaging Strehl ratio (panchromatically > 98% over its entire 0.8 - 2.4 micron wavelength regime) and coronagraphic imaging capability, celebrated its tenth anniversary in space earlier this year. These combined instrumental attributes uniquely contribute to its capability as a high-contrast imager as demonstrated by its continuing production of new examples of spatially resolved scattered-light imagery of both optically thick and thin circumstellar disks and sub-stellar companions to young stars and brown dwarfs well into the (several) Jovian mass range. We review these capabilities, illustrating with observationally based results, including examples obtained since HST's entry into two gyro guiding mode in mid 2005. The advent of a recently introduced, and now commissioned and calibrated, coronagraphic polarimetry mode has enabled very-high contrast 2 micron imaging polarimetry with 0.2 spatial resolution. Such imagery provides important constraints in the interpretation of disk-scattered starlight in assessing circumstellar disk geometries and the physical properties of their constituent grains. We demonstrate this new capability with observational results from two currently-executing HST programs obtaining 2 micron coronagraphic polarimetric images of circumstellar T-Tauri and debris disks.

Trunk Motion System (TMS) Using Printed Body Worn Sensor (BWS) via Data Fusion Approach

PubMed Central

Mokhlespour Esfahani, Mohammad Iman; Zobeiri, Omid; Moshiri, Behzad; Narimani, Roya; Mehravar, Mohammad; Rashedi, Ehsan; Parnianpour, Mohamad

2017-01-01

Human movement analysis is an important part of biomechanics and rehabilitation, for which many measurement systems are introduced. Among these, wearable devices have substantial biomedical applications, primarily since they can be implemented both in indoor and outdoor applications. In this study, a Trunk Motion System (TMS) using printed Body-Worn Sensors (BWS) is designed and developed. TMS can measure three-dimensional (3D) trunk motions, is lightweight, and is a portable and non-invasive system. After the recognition of sensor locations, twelve BWSs were printed on stretchable clothing with the purpose of measuring the 3D trunk movements. To integrate BWSs data, a neural network data fusion algorithm was used. The outcome of this algorithm along with the actual 3D anatomical movements (obtained by Qualisys system) were used to calibrate the TMS. Three healthy participants with different physical characteristics participated in the calibration tests. Seven different tasks (each repeated three times) were performed, involving five planar, and two multiplanar movements. Results showed that the accuracy of TMS system was less than 1.0°, 0.8°, 0.6°, 0.8°, 0.9°, and 1.3° for flexion/extension, left/right lateral bending, left/right axial rotation, and multi-planar motions, respectively. In addition, the accuracy of TMS for the identified movement was less than 2.7°. TMS, developed to monitor and measure the trunk orientations, can have diverse applications in clinical, biomechanical, and ergonomic studies to prevent musculoskeletal injuries, and to determine the impact of interventions. PMID:28075342

Three-dimensional printing as a technology supporting the treatment of lower limb deformity and shortening with the Ilizarov method.

PubMed

Morasiewicz, Piotr; Burzyńska, Karolina; Orzechowski, Wiktor; Dragan, Szymon Łukasz; Dragan, Szymon Feliks; Filipiak, Jarosław

2018-04-20

Treatment of multiplanar deformities, especially in younger children, requires construction of a complex Ilizarov fixator, frequently with small dimensions. The aim of this study is to verify clinical application of a3D-printed bone model in treatment with the Ilizarov method. The study involved a 6-year-old child in whom clinical and radiological examination revealed multiplanar deformity of the right leg. Then, 3D models of individual bones were printed by means of additive manufacturing and were used as a scaffold to install the Ilizarov apparatus. To compare the expected and factual axial correction and lengthening, we measured spatial orientation of bone fragments three times. The factual axial correction and lengthening were determined with a photometric technique. Ilizarov fixator with a configuration developed using a 3D model of the treated bone was mounted on the patient's leg. Corticotomy was carried out at the proximal metaphysis of the right tibia, along with osteotomy of the right talus. The treatment resulted in a 3.5-cm lengthening of the limb and a 7° correction of valgus angle. The values of actual lengthening and axial correction were 4.1% lower than the expected values of these parameters. Orthopedists should consider differences between the expected and actual lengthening and axial correction in planning treatment with the Ilizarov method. Three-dimensional printing is a useful technology that can be used to support treatment with the Ilizarov method. Copyright © 2018 IPEM. Published by Elsevier Ltd. All rights reserved.

Field observations using an AOTF polarimetric imaging spectrometer

NASA Technical Reports Server (NTRS)

Cheng, Li-Jen; Hamilton, Mike; Mahoney, Colin; Reyes, George

1993-01-01

This paper reports preliminary results of recent field observations using a prototype acousto-optic tunable filter (AOTF) polarimetric imaging spectrometer. The data illustrate application potentials for geoscience. The operation principle of this instrument is different from that of current airborne multispectral imaging instruments, such as AVIRIS. The AOTF instrument takes two orthogonally polarized images at a desired wavelength at one time, whereas AVIRIS takes a spectrum over a predetermined wavelength range at one pixel at a time and the image is constructed later. AVIRIS does not have any polarization measuring capability. The AOTF instrument could be a complement tool to AVIRIS. Polarization measurement is a desired capability for many applications in remote sensing. It is well know that natural light is often polarized due to various scattering phenomena in the atmosphere. Also, scattered light from canopies is reported to have a polarized component. To characterize objects of interest correctly requires a remote sensing imaging spectrometer capable of measuring object signal and background radiation in both intensity and polarization so that the characteristics of the object can be determined. The AORF instrument has the capability to do so. The AOTF instrument has other unique properties. For example, it can provide spectral images immediately after the observation. The instrument can also allow observations to be tailored in real time to perform the desired experiments and to collect only required data. Consequently, the performance in each mission can be increased with minimal resources. The prototype instrument was completed in the beginning of this year. A number of outdoor field experiments were performed with the objective to evaluate the capability of this new technology for remote sensing applications and to determine issues for further improvements.

Automated T2-mapping of the Menisci From Magnetic Resonance Images in Patients with Acute Knee Injury.

PubMed

Paproki, Anthony; Engstrom, Craig; Strudwick, Mark; Wilson, Katharine J; Surowiec, Rachel K; Ho, Charles; Crozier, Stuart; Fripp, Jurgen

2017-10-01

This study aimed to evaluate the accuracy of an automated method for segmentation and T2 mapping of the medial meniscus (MM) and lateral meniscus (LM) in clinical magnetic resonance images from patients with acute knee injury. Eighty patients scheduled for surgery of an anterior cruciate ligament or meniscal injury underwent magnetic resonance imaging of the knee (multiplanar two-dimensional [2D] turbo spin echo [TSE] or three-dimensional [3D]-TSE examinations, T2 mapping). Each meniscus was automatically segmented from the 2D-TSE (composite volume) or 3D-TSE images, auto-partitioned into anterior, mid, and posterior regions, and co-registered onto the T2 maps. The Dice similarity index (spatial overlap) was calculated between automated and manual segmentations of 2D-TSE (15 patients), 3D-TSE (16 patients), and corresponding T2 maps (31 patients). Pearson and intraclass correlation coefficients (ICC) were calculated between automated and manual T2 values. T2 values were compared (Wilcoxon rank sum tests) between torn and non-torn menisci for the subset of patients with both manual and automated segmentations to compare statistical outcomes of both methods. The Dice similarity index values for the 2D-TSE, 3D-TSE, and T2 map volumes, respectively, were 76.4%, 84.3%, and 75.2% for the MM and 76.4%, 85.1%, and 76.1% for the LM. There were strong correlations between automated and manual T2 values (r MM  = 0.95, ICC MM  = 0.94; r LM  = 0.97, ICC LM  = 0.97). For both the manual and the automated methods, T2 values were significantly higher in torn than in non-torn MM for the full meniscus and its subregions (P < .05). Non-torn LM had higher T2 values than non-torn MM (P < .05). The present automated method offers a promising alternative to manual T2 mapping analyses of the menisci and a considerable advance for integration into clinical workflows. Copyright © 2017 The Association of University Radiologists. All rights reserved.

Depth-resolved ballistic imaging in a low-depth-of-field optical Kerr gated imaging system

NASA Astrophysics Data System (ADS)

Zheng, Yipeng; Tan, Wenjiang; Si, Jinhai; Ren, YuHu; Xu, Shichao; Tong, Junyi; Hou, Xun

2016-09-01

We demonstrate depth-resolved imaging in a ballistic imaging system, in which a heterodyned femtosecond optical Kerr gate is introduced to extract useful imaging photons for detecting an object hidden in turbid media and a compound lens is proposed to ensure both the depth-resolved imaging capability and the long working distance. Two objects of about 15-μm widths hidden in a polystyrene-sphere suspension have been successfully imaged with approximately 600-μm depth resolution. Modulation-transfer-function curves with the object in and away from the object plane have also been measured to confirm the depth-resolved imaging capability of the low-depth-of-field (low-DOF) ballistic imaging system. This imaging approach shows potential for application in research of the internal structure of highly scattering fuel spray.

Depth-resolved ballistic imaging in a low-depth-of-field optical Kerr gated imaging system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Yipeng; Tan, Wenjiang, E-mail: tanwenjiang@mail.xjtu.edu.cn; Si, Jinhai

2016-09-07

We demonstrate depth-resolved imaging in a ballistic imaging system, in which a heterodyned femtosecond optical Kerr gate is introduced to extract useful imaging photons for detecting an object hidden in turbid media and a compound lens is proposed to ensure both the depth-resolved imaging capability and the long working distance. Two objects of about 15-μm widths hidden in a polystyrene-sphere suspension have been successfully imaged with approximately 600-μm depth resolution. Modulation-transfer-function curves with the object in and away from the object plane have also been measured to confirm the depth-resolved imaging capability of the low-depth-of-field (low-DOF) ballistic imaging system. Thismore » imaging approach shows potential for application in research of the internal structure of highly scattering fuel spray.« less

Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

PubMed

Rieger, Michael; Czermak, Benedikt; El Attal, Rene; Sumann, Günther; Jaschke, Werner; Freund, Martin

2009-03-01

The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department. Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition. The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up. This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

Double Crush of L5 Spinal Nerve Root due to L4/5 Lateral Recess Stenosis and Bony Spur Formation of Lumbosacral Transitional Vertebra Pseudoarticulation: A Case Report and Review

PubMed Central

Iwasaki, Motoyuki; Akiyama, Masahiko; Koyanagi, Izumi; Niiya, Yoshimasa; Ihara, Tatsuo; Houkin, Kiyohiro

2017-01-01

We present a case of double-crushed L5 nerve root symptoms caused by inside and outside of the spinal canal with spur formation of the lumbosacral transitional vertebra (LSTV). A 78-year-old man presented with 7-year history of moderate paresis of his toe and left leg pain when walking. Magnetic resonance imaging (MRI) revealed spinal stenosis at the L3/4 and 4/5 spinal levels and he underwent wide fenestration of both levels. Leg pain disappeared and 6-min walk distance (6MWD) improved after surgery, however, the numbness in his toes increased and 6MWD decreased 9 months after surgery. Repeated MR and 3D multiplanar reconstructed computed tomography (CT) images showed extraforaminal impingement of the L5 root by bony spur of the left LSTV. He underwent second decompression surgery of the L5/S via the left sided Wiltse approach, resulting in the improvement of his symptoms. The impingement of L5 spinal nerve root between the transverse process of the fifth lumbar vertebra and the sacral ala is a rare entity of the pathology called “far-out syndrome (FOS)”. Especially, the bony spur formation secondary to the anomalous articulation of the LSTV (LSPA) has not been reported. These articulations could be due to severe disc degeneration, following closer distance and contact between the transverse process and the sacral ala. To our knowledge, this is the first report describing a case with this pathology and may be considered in cases of failed back surgery syndromes (FBSS) of the L5 root symptoms. PMID:29018654

The characteristic clinical symptoms of C-4 radiculopathy caused by ossification of the posterior longitudinal ligament.

PubMed

Katsumi, Keiichi; Yamazaki, Akiyoshi; Watanabe, Kei; Hirano, Toru; Ohashi, Masayuki; Endo, Naoto

2014-05-01

Cervical radiculopathy of the C2-4 spinal nerves is a rare condition and is poorly documented in terms of clinical symptoms, hindering its detection during initial patient screening based on imaging diagnostics. The authors describe in detail the clinical symptoms and successful surgical treatment of a patient diagnosed with isolated C-4 radiculopathy. This 41-year-old man suffered from sleep disturbance because of pain behind the right ear, along the right clavicle, and at the back of his neck on the right side. The Jackson and Spurling tests were positive, with pain radiating to the area behind the patient's ear. Unlike in cases of radiculopathy involving the C5-8 spinal nerves, no loss of upper-extremity motor function was seen. Magnetic resonance imaging showed foraminal stenosis at the C3-4 level on the right side, and multiplanar reconstruction CT revealed a beak-type ossification of the posterior longitudinal ligament in the foraminal region at the same level. In the absence of intracranial lesions or spinal cord compressive lesions, the positive Jackson and Spurling tests and the C3-4 foraminal stenosis were indicative of isolated C-4 radiculopathy. Microscopic foraminotomy was performed at the C3-4 vertebral level and the ossified lesion was resected. The patient's symptoms completely resolved immediately after surgery. To the authors' knowledge, this report is the first to describe the symptomatic features of isolated C-4 radiculopathy, in a case in which the diagnosis has been confirmed by both radiological findings and surgical outcome. Based on this case study, the authors conclude that the characteristic symptoms of C-4 radiculopathy are the presence of pain behind the ear and in the clavicular region in the absence of upper-limb involvement.

3D echocardiographic analysis of aortic annulus for transcatheter aortic valve replacement using novel aortic valve quantification software: Comparison with computed tomography.

PubMed

Mediratta, Anuj; Addetia, Karima; Medvedofsky, Diego; Schneider, Robert J; Kruse, Eric; Shah, Atman P; Nathan, Sandeep; Paul, Jonathan D; Blair, John E; Ota, Takeyoshi; Balkhy, Husam H; Patel, Amit R; Mor-Avi, Victor; Lang, Roberto M

2017-05-01

With the increasing use of transcatheter aortic valve replacement (TAVR) in patients with aortic stenosis (AS), computed tomography (CT) remains the standard for annulus sizing. However, 3D transesophageal echocardiography (TEE) has been an alternative in patients with contraindications to CT. We sought to (1) test the feasibility, accuracy, and reproducibility of prototype 3DTEE analysis software (Philips) for aortic annular measurements and (2) compare the new approach to the existing echocardiographic techniques. We prospectively studied 52 patients who underwent gated contrast CT, procedural 3DTEE, and TAVR. 3DTEE images were analyzed using novel semi-automated software designed for 3D measurements of the aortic root, which uses multiplanar reconstruction, similar to CT analysis. Aortic annulus measurements included area, perimeter, and diameter calculations from these measurements. The results were compared to CT-derived values. Additionally, 3D echocardiographic measurements (3D planimetry and mitral valve analysis software adapted for the aortic valve) were also compared to the CT reference values. 3DTEE image quality was sufficient in 90% of patients for aortic annulus measurements using the new software, which were in good agreement with CT (r-values: .89-.91) and small (<4%) inter-modality nonsignificant biases. Repeated measurements showed <10% measurements variability. The new 3D analysis was the more accurate and reproducible of the existing echocardiographic techniques. Novel semi-automated 3DTEE analysis software can accurately measure aortic annulus in patients with severe AS undergoing TAVR, in better agreement with CT than the existing methodology. Accordingly, intra-procedural TEE could potentially replace CT in patients where CT carries significant risk. © 2017, Wiley Periodicals, Inc.

Development and utilization of a web-based application as a robust radiology teaching tool (radstax) for medical student anatomy teaching.

PubMed

Colucci, Philip G; Kostandy, Petro; Shrauner, William R; Arleo, Elizabeth; Fuortes, Michele; Griffin, Andrew S; Huang, Yun-Han; Juluru, Krishna; Tsiouris, Apostolos John

2015-02-01

Rationale and Objectives: The primary role of radiology in the preclinical setting is the use of imaging to improve students' understanding of anatomy. Many currently available Web-based anatomy programs include either suboptimal or overwhelming levels of detail for medical students.Our objective was to develop a user-friendly software program that anatomy instructors can completely tailor to match the desired level of detail for their curriculum, meets the unique needs of the first- and the second-year medical students, and is compatible with most Internet browsers and tablets.Materials and Methods: RadStax is a Web-based application developed using free, open-source, ubiquitous software. RadStax was first introduced as an interactive resource for independent study and later incorporated into lectures. First- and second-year medical students were surveyed for quantitative feedback regarding their experience.Results: RadStax was successfully introduced into our medical school curriculum. It allows the creation of learning modules with labeled multiplanar (MPR) image sets, basic anatomic information, and a self-assessment feature. The program received overwhelmingly positive feedback from students. Of 115 students surveyed, 87.0% found it highly effective as a study tool and 85.2% reported high user satisfaction with the program.Conclusions: RadStax is a novel application for instructors wishing to create an atlas of labeled MPR radiologic studies tailored to meet the specific needs their curriculum. Simple and focused, it provides an interactive experience for students similar to the practice of radiologists.This program is a robust anatomy teaching tool that effectively aids in educating the preclinical medical student.

Severity mapping of the proximal femur: a new method for assessing hip osteoarthritis with computed tomography.

PubMed

Turmezei, T D; Lomas, D J; Hopper, M A; Poole, K E S

2014-10-01

Plain radiography has been the mainstay of imaging assessment in osteoarthritis for over 50 years, but it does have limitations. Here we present the methodology and results of a new technique for identifying, grading, and mapping the severity and spatial distribution of osteoarthritic disease features at the hip in 3D with clinical computed tomography (CT). CT imaging of 456 hips from 230 adult female volunteers (mean age 66 ± 17 years) was reviewed using 3D multiplanar reformatting to identify bone-related radiological features of osteoarthritis, namely osteophytes, subchondral cysts and joint space narrowing. Scoresheets dividing up the femoral head, head-neck region and the joint space were used to register the location and severity of each feature (scored from 0 to 3). Novel 3D cumulative feature severity maps were then created to display where the most severe disease features from each individual were anatomically located across the cohort. Feature severity maps showed a propensity for osteophytes at the inferoposterior and superolateral femoral head-neck junction. Subchondral cysts were a less common and less localised phenomenon. Joint space narrowing <1.5 mm was recorded in at least one sector of 83% of hips, but most frequently in the posterolateral joint space. This is the first description of hip osteoarthritis using unenhanced clinical CT in which we describe the co-localisation of posterior osteophytes and joint space narrowing for the first time. We believe this technique can perform several important roles in future osteoarthritis research, including phenotyping and sensitive disease assessment in 3D. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Usefulness of computed tomography in pre-surgical evaluation of maxillo-facial pathology with rapid prototyping and surgical pre-planning by virtual reality.

PubMed

Toso, Francesco; Zuiani, Chiara; Vergendo, Maurizio; Salvo, Iolanda; Robiony, Massimo; Politi, Massimo; Bazzocchi, Massimo

2005-01-01

To validate a protocol for creating virtual models to be used in the construction of solid prototypes useful for the planning-simulation of maxillo-facial surgery, in particular for very complex anatomic and pathologic problems. To optimize communications between the radiology, engineering and surgical laboratories. We studied 16 patients with different clinical problems of the maxillo-facial district. Exams were performed with multidetector computed tomography (MDCT) and single slice computed tomography (SDCT) with axial scans and collimation of 0.5-2 mm, and reconstruction interval of 1 mm. Subsequently we performed 2D multiplanar reconstructions and 3D volume-rendering reconstructions. We exported the DICOM images to the engineering laboratory, to recognize and isolate the bony structures by software. With these data the solid prototypes were generated using stereolitography. To date, surgery has been preformed on 12 patients after simulation of the procedure on the stereolithographyc model. The solid prototypes constructed in the difficult cases were sufficiently detailed despite problems related to the artefacts generated by dental fillings an d prostheses. In the remaining cases the MPR/3D images were sufficiently detailed for surgical planning. The surgical results were excellent in all patients who underwent surgery, and the surgeons were satisfied with the improvement in quality and the reduction in time required for the procedure. MDCT enables rapid prototyping using solid replication, which was very helpful in maxillo-facial surgery, despite problems related to artifacts due to dental fillings and prosthesis within the acquisition field; solutions for this problem are work in progress. The protocol used for communication between the different laboratories was valid and reproducible.

Evaluation of dynamic infrared thermography as an alternative to CT angiography for perforator mapping in breast reconstruction: a clinical study.

PubMed

Weum, Sven; Mercer, James B; de Weerd, Louis

2016-07-15

The current gold standard for preoperative perforator mapping in breast reconstruction with a DIEP flap is CT angiography (CTA). Dynamic infrared thermography (DIRT) is an imaging method that does not require ionizing radiation or contrast injection. We evaluated if DIRT could be an alternative to CTA in perforator mapping. Twenty-five patients scheduled for secondary breast reconstruction with a DIEP flap were included. Preoperatively, the lower abdomen was examined with hand-held Doppler, DIRT and CTA. Arterial Doppler sound locations were marked on the skin. DIRT examination involved rewarming of the abdominal skin after a mild cold challenge. The locations of hot spots on DIRT were compared with the arterial Doppler sound locations. The rate and pattern of rewarming of the hot spots were analyzed. Multiplanar CT reconstructions were used to see if hot spots were related to perforators on CTA. All flaps were based on the perforator selected with DIRT and the surgical outcome was analyzed. First appearing hot spots were always associated with arterial Doppler sounds and clearly visible perforators on CTA. The hot spots on DIRT images were always slightly laterally located in relation to the exit points of the associated perforators through the rectus abdominis fascia on CTA. Some periumbilical perforators were not associated with hot spots and showed communication with the superficial inferior epigastric vein on CTA. The selected perforators adequately perfused all flaps. This study confirms that perforators selected with DIRT have arterial Doppler sound, are clearly visible on CTA and provide adequate perfusion for DIEP breast reconstruction. Retrospectively registered at ClinicalTrials.gov with identifier NCT02806518 .

Development and Utilization of a Web-Based Application as a Robust Radiology Teaching Tool (RadStax) for Medical Student Anatomy Teaching

PubMed Central

Colucci, Philip G.; Kostandy, Petro; Shrauner, William R.; Arleo, Elizabeth; Fuortes, Michele; Griffin, Andrew S.; Huang, Yun-Han; Juluru, Krishna; Tsiouris, Apostolos John

2016-01-01

Rationale and Objectives The primary role of radiology in the preclinical setting is the use of imaging to improve students’ understanding of anatomy. Many currently available Web-based anatomy programs include either suboptimal or overwhelming levels of detail for medical students. Our objective was to develop a user-friendly software program that anatomy instructors can completely tailor to match the desired level of detail for their curriculum, meets the unique needs of the first- and the second-year medical students, and is compatible with most Internet browsers and tablets. Materials and Methods RadStax is a Web-based application developed using free, open-source, ubiquitous software. RadStax was first introduced as an interactive resource for independent study and later incorporated into lectures. First- and second-year medical students were surveyed for quantitative feedback regarding their experience. Results RadStax was successfully introduced into our medical school curriculum. It allows the creation of learning modules with labeled multiplanar (MPR) image sets, basic anatomic information, and a self-assessment feature. The program received overwhelmingly positive feedback from students. Of 115 students surveyed, 87.0% found it highly effective as a study tool and 85.2% reported high user satisfaction with the program. Conclusions RadStax is a novel application for instructors wishing to create an atlas of labeled MPR radiologic studies tailored to meet the specific needs their curriculum. Simple and focused, it provides an interactive experience for students similar to the practice of radiologists. This program is a robust anatomy teaching tool that effectively aids in educating the preclinical medical student. PMID:25964956

Characterizing saccular aortic arch aneurysms from the geometry-flow dynamics relationship.

PubMed

Natsume, Kayoko; Shiiya, Norihiko; Takehara, Yasuo; Sugiyama, Masataka; Satoh, Hiroshi; Yamashita, Katsushi; Washiyama, Naoki

2017-06-01

Low wall shear stress (WSS) has been reported to be associated with accelerated atherosclerosis, aneurysm growth, or rupture. We evaluated the geometry of aortic arch aneurysms and their relationship with WSS by using the 4-dimensional flow magnetic resonance imaging to better characterize the saccular aneurysms. We analyzed the geometry in 100 patients using multiplanar reconstruction of computed tomography. We evaluated WSS and vortex flow using 4-dimensional flow magnetic resonance imaging in 16 of them, which were compared with 8 age-matched control subjects and eight healthy young volunteers. Eighty-two patients had a saccular aneurysm, and 18 had a fusiform aneurysm. External diameter/aneurysm length ratio and sac depth/neck width ratio of the fusiform aneurysms were constant at 0.76 ± 0.18 and 0.23 ± 0.09, whereas those of saccular aneurysms, especially those involving the outer curvature, were higher and more variable. Vortex flow was always present in the aneurysms, resulting in low WSS. When the sac depth/neck width ratio was less than 0.8, peak WSS correlated inversely with luminal diameter even in the saccular aneurysms. When this ratio exceeded 0.8, which was the case only with the saccular aneurysms, such correlation no longer existed and WSS was invariably low. Fusiform aneurysms elongate as they dilate, and WSS is lower as the diameter is larger. Saccular aneurysms dilate without proportionate elongation, and they, especially those occupying the inner curvature, have higher and variable sac depth/neck width ratio. When this ratio exceeds 0.8, WSS is low regardless of diameter, which may explain their malignant clinical behavior. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Imaging of blood cells based on snapshot Hyper-Spectral Imaging systems

NASA Astrophysics Data System (ADS)

Robison, Christopher J.; Kolanko, Christopher; Bourlai, Thirimachos; Dawson, Jeremy M.

2015-05-01

Snapshot Hyper-Spectral imaging systems are capable of capturing several spectral bands simultaneously, offering coregistered images of a target. With appropriate optics, these systems are potentially able to image blood cells in vivo as they flow through a vessel, eliminating the need for a blood draw and sample staining. Our group has evaluated the capability of a commercial Snapshot Hyper-Spectral imaging system, the Arrow system from Rebellion Photonics, in differentiating between white and red blood cells on unstained blood smear slides. We evaluated the imaging capabilities of this hyperspectral camera; attached to a microscope at varying objective powers and illumination intensity. Hyperspectral data consisting of 25, 443x313 hyperspectral bands with ~3nm spacing were captured over the range of 419 to 494nm. Open-source hyper-spectral data cube analysis tools, used primarily in Geographic Information Systems (GIS) applications, indicate that white blood cells features are most prominent in the 428-442nm band for blood samples viewed under 20x and 50x magnification over a varying range of illumination intensities. These images could potentially be used in subsequent automated white blood cell segmentation and counting algorithms for performing in vivo white blood cell counting.

Imaging characteristics of photogrammetric camera systems

USGS Publications Warehouse

Welch, R.; Halliday, J.

1973-01-01

In view of the current interest in high-altitude and space photographic systems for photogrammetric mapping, the United States Geological Survey (U.S.G.S.) undertook a comprehensive research project designed to explore the practical aspects of applying the latest image quality evaluation techniques to the analysis of such systems. The project had two direct objectives: (1) to evaluate the imaging characteristics of current U.S.G.S. photogrammetric camera systems; and (2) to develop methodologies for predicting the imaging capabilities of photogrammetric camera systems, comparing conventional systems with new or different types of systems, and analyzing the image quality of photographs. Image quality was judged in terms of a number of evaluation factors including response functions, resolving power, and the detectability and measurability of small detail. The limiting capabilities of the U.S.G.S. 6-inch and 12-inch focal length camera systems were established by analyzing laboratory and aerial photographs in terms of these evaluation factors. In the process, the contributing effects of relevant parameters such as lens aberrations, lens aperture, shutter function, image motion, film type, and target contrast procedures for analyzing image quality and predicting and comparing performance capabilities. ?? 1973.

Doppler imaging using spectrally-encoded endoscopy

PubMed Central

Yelin, Dvir; Bouma, B. E.; Rosowsky, J. J.; Tearney, G. J.

2009-01-01

The capability to image tissue motion such as blood flow through an endoscope could have many applications in medicine. Spectrally encoded endoscopy (SEE) is a recently introduced technique that utilizes a single optical fiber and miniature diffractive optics to obtain endoscopic images through small diameter probes. Using spectral-domain interferometry, SEE is furthermore capable of three-dimensional volume imaging at video rates. Here we show that by measuring relative spectral phases, this technology can additionally measure Doppler shifts. Doppler SEE is demonstrated in flowing Intralipid phantoms and vibrating middle ear ossicles. PMID:18795020

Role of Kinetic Modeling in Biomedical Imaging

PubMed Central

Huang, Sung-Cheng

2009-01-01

Biomedical imaging can reveal clear 3-dimensional body morphology non-invasively with high spatial resolution. Its efficacy, in both clinical and pre-clinical settings, is enhanced with its capability to provide in vivo functional/biological information in tissue. The role of kinetic modeling in providing biological/functional information in biomedical imaging is described. General characteristics and limitations in extracting biological information are addressed and practical approaches to solve the problems are discussed and illustrated with examples. Some future challenges and opportunities for kinetic modeling to expand the capability of biomedical imaging are also presented. PMID:20640185

Improved Cloud Detection Utilizing Defense Meteorological Satellite Program near Infrared Measurements

DTIC Science & Technology

1982-01-27

Visible 3. 3 Ea r th Location, Colocation, and Normalization 4. IMAGE ANALYSIS 4. 1 Interactive Capabilities 4.2 Examples 5. AUTOMATED CLOUD...computer Interactive Data Access System (McIDAS) before image analysis and algorithm development were done. Earth-location is an automated procedure to...the factor l / s in (SSE) toward the gain settings given in Table 5. 4. IMAGE ANALYSIS 4.1 Interactive Capabilities The development of automated

Photoacoustic Imaging for Cancer Detection and Staging

PubMed Central

Mehrmohammadi, Mohammad; Yoon, Soon Joon; Yeager, Douglas; Emelianov, Stanislav Y.

2013-01-01

Cancer is one of the leading causes of death in the world. Diagnosing a cancer at its early stages of development can decrease the mortality rate significantly and reduce healthcare costs. Over the past two decades, photoacoustic imaging has seen steady growth and has demonstrated notable capabilities to detect cancerous cells and stage cancer. Furthermore, photoacoustic imaging combined with ultrasound imaging and augmented with molecular targeted contrast agents is capable of imaging cancer at the cellular and molecular level, thus opening diverse opportunities to improve diagnosis of tumors, detect circulating tumor cells and identify metastatic lymph nodes. In this paper we introduce the principles of photoacoustic imaging, and review recent developments in photoacoustic imagingas an emerging imaging modality for cancer diagnosis and staging. PMID:24032095

High Resolution Imaging of the Sun with CORONAS-1

NASA Technical Reports Server (NTRS)

Karovska, Margarita

1998-01-01

We applied several image restoration and enhancement techniques, to CORONAS-I images. We carried out the characterization of the Point Spread Function (PSF) using the unique capability of the Blind Iterative Deconvolution (BID) technique, which recovers the real PSF at a given location and time of observation, when limited a priori information is available on its characteristics. We also applied image enhancement technique to extract the small scale structure imbeded in bright large scale structures on the disk and on the limb. The results demonstrate the capability of the image post-processing to substantially increase the yield from the space observations by improving the resolution and reducing noise in the images.

A novel dual-color bifocal imaging system for single-molecule studies.

PubMed

Jiang, Chang; Kaul, Neha; Campbell, Jenna; Meyhofer, Edgar

2017-05-01

In this paper, we report the design and implementation of a dual-color bifocal imaging (DBI) system that is capable of acquiring two spectrally distinct, spatially registered images of objects located in either same or two distinct focal planes. We achieve this by separating an image into two channels with distinct chromatic properties and independently focusing both images onto a single CCD camera. The two channels in our device are registered with subpixel accuracy, and long-term stability of the registered images with nanometer-precision was accomplished by reducing the drift of the images to ∼5 nm. We demonstrate the capabilities of our DBI system by imaging biomolecules labeled with spectrally distinct dyes and micro- and nano-sized spheres located in different focal planes.

Material classification and automatic content enrichment of images using supervised learning and knowledge bases

NASA Astrophysics Data System (ADS)

Mallepudi, Sri Abhishikth; Calix, Ricardo A.; Knapp, Gerald M.

2011-02-01

In recent years there has been a rapid increase in the size of video and image databases. Effective searching and retrieving of images from these databases is a significant current research area. In particular, there is a growing interest in query capabilities based on semantic image features such as objects, locations, and materials, known as content-based image retrieval. This study investigated mechanisms for identifying materials present in an image. These capabilities provide additional information impacting conditional probabilities about images (e.g. objects made of steel are more likely to be buildings). These capabilities are useful in Building Information Modeling (BIM) and in automatic enrichment of images. I2T methodologies are a way to enrich an image by generating text descriptions based on image analysis. In this work, a learning model is trained to detect certain materials in images. To train the model, an image dataset was constructed containing single material images of bricks, cloth, grass, sand, stones, and wood. For generalization purposes, an additional set of 50 images containing multiple materials (some not used in training) was constructed. Two different supervised learning classification models were investigated: a single multi-class SVM classifier, and multiple binary SVM classifiers (one per material). Image features included Gabor filter parameters for texture, and color histogram data for RGB components. All classification accuracy scores using the SVM-based method were above 85%. The second model helped in gathering more information from the images since it assigned multiple classes to the images. A framework for the I2T methodology is presented.

A digital ISO expansion technique for digital cameras

NASA Astrophysics Data System (ADS)

Yoo, Youngjin; Lee, Kangeui; Choe, Wonhee; Park, SungChan; Lee, Seong-Deok; Kim, Chang-Yong

2010-01-01

Market's demands of digital cameras for higher sensitivity capability under low-light conditions are remarkably increasing nowadays. The digital camera market is now a tough race for providing higher ISO capability. In this paper, we explore an approach for increasing maximum ISO capability of digital cameras without changing any structure of an image sensor or CFA. Our method is directly applied to the raw Bayer pattern CFA image to avoid non-linearity characteristics and noise amplification which are usually deteriorated after ISP (Image Signal Processor) of digital cameras. The proposed method fuses multiple short exposed images which are noisy, but less blurred. Our approach is designed to avoid the ghost artifact caused by hand-shaking and object motion. In order to achieve a desired ISO image quality, both low frequency chromatic noise and fine-grain noise that usually appear in high ISO images are removed and then we modify the different layers which are created by a two-scale non-linear decomposition of an image. Once our approach is performed on an input Bayer pattern CFA image, the resultant Bayer image is further processed by ISP to obtain a fully processed RGB image. The performance of our proposed approach is evaluated by comparing SNR (Signal to Noise Ratio), MTF50 (Modulation Transfer Function), color error ~E*ab and visual quality with reference images whose exposure times are properly extended into a variety of target sensitivity.

Real-time in vivo imaging of human lymphatic system using an LED-based photoacoustic/ultrasound imaging system

NASA Astrophysics Data System (ADS)

Kuniyil Ajith Singh, Mithun; Agano, Toshitaka; Sato, Naoto; Shigeta, Yusuke; Uemura, Tetsuji

2018-02-01

Non-invasive in vivo imaging of lymphatic system is of paramount importance for analyzing the functions of lymphatic vessels, and for investigating their contribution to metastasis. Recently, we introduced a multi-wavelength real-time LED-based photoacoustic/ultrasound system (AcousticX). In this work, for the first time, we demonstrate that AcousticX is capable of real-time imaging of human lymphatic system. Results demonstrate the capability of this system to image vascular and lymphatic vessels simultaneously. This could potentially provide detailed information regarding the interconnected roles of lymphatic and vascular systems in various diseases, therefore fostering the growth of therapeutic interventions.

An ultra-low power CMOS image sensor with on-chip energy harvesting and power management capability.

PubMed

Cevik, Ismail; Huang, Xiwei; Yu, Hao; Yan, Mei; Ay, Suat U

2015-03-06

An ultra-low power CMOS image sensor with on-chip energy harvesting and power management capability is introduced in this paper. The photodiode pixel array can not only capture images but also harvest solar energy. As such, the CMOS image sensor chip is able to switch between imaging and harvesting modes towards self-power operation. Moreover, an on-chip maximum power point tracking (MPPT)-based power management system (PMS) is designed for the dual-mode image sensor to further improve the energy efficiency. A new isolated P-well energy harvesting and imaging (EHI) pixel with very high fill factor is introduced. Several ultra-low power design techniques such as reset and select boosting techniques have been utilized to maintain a wide pixel dynamic range. The chip was designed and fabricated in a 1.8 V, 1P6M 0.18 µm CMOS process. Total power consumption of the imager is 6.53 µW for a 96 × 96 pixel array with 1 V supply and 5 fps frame rate. Up to 30 μW of power could be generated by the new EHI pixels. The PMS is capable of providing 3× the power required during imaging mode with 50% efficiency allowing energy autonomous operation with a 72.5% duty cycle.

X-Ray and near-infrared imaging: similarities, differences and combinations

NASA Astrophysics Data System (ADS)

Pogue, Brian W.

2010-02-01

The integration of x-ray imaging with optical imaging is becoming routine at the pre-clinical level, as both projection and tomography systems are now commercially integrated as packaged systems. Yet, the differences between their capabilities are wide, and there is still perhaps a lack of appreciation about how difference pre-clinical x-ray systems are from clinical x-ray systems. In this survey, the key advantages of each approach, x-ray and optical, are described, and the potential synergies and deficiencies are discussed. In simple terms, the major benefit of optical imaging is in the spectroscopic capabilities, which allow the potential for imaging fluorescent agents in vivo, and the future potential for imaging multiple species at a time with spectral discrimination or spectral fitting of the data. In comparison, multienergy x-ray systems are being realized in clinical use, or automated discrimination of soft versus hard tissues, and the combination of optical imaging with this type of dual-energy x-ray imaging will significantly enhance the capabilities of the hybrid systems. Unfortunately, the power of dual energy imaging is not as possible at the pre-clinical stage, because of the limitations of contrast-resolution and x-ray dose. This is discussed and future human systems outlined.

An Ultra-Low Power CMOS Image Sensor with On-Chip Energy Harvesting and Power Management Capability

PubMed Central

Cevik, Ismail; Huang, Xiwei; Yu, Hao; Yan, Mei; Ay, Suat U.

2015-01-01

An ultra-low power CMOS image sensor with on-chip energy harvesting and power management capability is introduced in this paper. The photodiode pixel array can not only capture images but also harvest solar energy. As such, the CMOS image sensor chip is able to switch between imaging and harvesting modes towards self-power operation. Moreover, an on-chip maximum power point tracking (MPPT)-based power management system (PMS) is designed for the dual-mode image sensor to further improve the energy efficiency. A new isolated P-well energy harvesting and imaging (EHI) pixel with very high fill factor is introduced. Several ultra-low power design techniques such as reset and select boosting techniques have been utilized to maintain a wide pixel dynamic range. The chip was designed and fabricated in a 1.8 V, 1P6M 0.18 µm CMOS process. Total power consumption of the imager is 6.53 µW for a 96 × 96 pixel array with 1 V supply and 5 fps frame rate. Up to 30 μW of power could be generated by the new EHI pixels. The PMS is capable of providing 3× the power required during imaging mode with 50% efficiency allowing energy autonomous operation with a 72.5% duty cycle. PMID:25756863

Multi-scale Functional and Molecular Photoacoustic Tomography

PubMed Central

Yao, Junjie; Xia, Jun; Wang, Lihong V.

2015-01-01

Photoacoustic tomography (PAT) combines rich optical absorption contrast with the high spatial resolution of ultrasound at depths in tissue. The high scalability of PAT has enabled anatomical imaging of biological structures ranging from organelles to organs. The inherent functional and molecular imaging capabilities of PAT have further allowed it to measure important physiological parameters and track critical cellular activities. Integration of PAT with other imaging technologies provides complementary capabilities and can potentially accelerate the clinical translation of PAT. PMID:25933617

Remote microscopy and volumetric imaging on the surface of icy satellites

NASA Astrophysics Data System (ADS)

Soto, Alejandro; Nowicki, Keith; Howett, Carly; Feldkhun, Daniel; Retherford, Kurt D.

2017-10-01

With NASA PIDDP support we have applied recent advancements in Fourier-domain microscopy to develop an instrument capable of microscopic imaging from meter-scale distances for use on a planetary lander on the surface of an icy satellite or other planetary bodies. Without moving parts, our instrument projects dynamic patterns of laser light onto a distant target using a lightweight large-aperture reflector, which then collects the light scattered or fluoresced by the target on a fast photon-bucket detector. Using Fourier Transform based techniques, we reconstruct an image from the detected light. The remote microscope has been demonstrated to produce 2D images with better than 15 micron lateral resolution for targets at a distance of 5 meters and is capable of linearly proportionally higher resolution at shorter distances. The remote microscope is also capable of providing three-dimensional (3D) microscopic imaging capabilities, allowing future surface scientists to explore the morphology of microscopic features in surface ices, for example. The instrument enables microscopic in-situ imaging during day or night without the use of a robotic arm, greatly facilitating the surface operations for a lander or rover while expanding the area of investigation near a landing site for improved science targeting. We are developing this remote microscope for in-situ planetary exploration as a collaboration between the Southwest Research Institute, LambdaMetrics, and the University of Colorado.

Big capabilities in small packages: hyperspectral imaging from a compact platform

NASA Astrophysics Data System (ADS)

Beasley, Matthew; Goldberg, Hannah; Voorhees, Christopher; Illsley, Peter

2016-09-01

We present the Compact Holographic Aberration-corrected Platform (CHAP) instrument, designed and developed at Planetary Resources Development Corporation. By combining a dispersive element with the secondary of a telescope, we are able to produce a relatively long focal length with moderate dispersion at the focal plane. This design enables us to build a capable hyperspectral imaging instrument within the size constraints of the Cubesat form-factor. The advantages of our design revolves around its simplicity: there are only two optical elements, producing both a white light and diffracted image. With the use of a replicated grating, we can produce a long focal length hyperspectral imager at a price point far below other spaceflight instruments. The design is scalable for larger platforms and since it has no transmitting optics and only two reflective surfaces could be designed to function at any desired wavelength. Our system will be capable of spectral imaging across the 400 to 900 nm spectral range for use in small body surveys.

C-arm cone beam computed tomography needle path overlay for fluoroscopic guided vertebroplasty.

PubMed

Tam, Alda L; Mohamed, Ashraf; Pfister, Marcus; Chinndurai, Ponraj; Rohm, Esther; Hall, Andrew F; Wallace, Michael J

2010-05-01

Retrospective review. To report our early clinical experience using C-arm cone beam computed tomography (C-arm CBCT) with fluoroscopic overlay for needle guidance during vertebroplasty. C-arm CBCT is advanced three-dimensional (3-D) imaging technology that is currently available on state-of-the-art flat panel based angiography systems. The imaging information provided by C-arm CBCT allows for the acquisition and reconstruction of "CT-like" images in flat panel based angiography/interventional suites. As part of the evolution of this technology, enhancements allowing the overlay of cross-sectional imaging information can now be integrated with real time fluoroscopy. We report our early clinical experience with C-arm CBCT with fluoroscopic overlay for needle guidance during vertebroplasty. This is a retrospective review of 10 consecutive oncology patients who underwent vertebroplasty of 13 vertebral levels using C-arm CBCT with fluoroscopic overlay for needle guidance from November 2007 to December 2008. Procedural data including vertebral level, approach (transpedicular vs. extrapedicular), access (bilateral vs. unilateral) and complications were recorded. Technical success with the overlay technology was assessed based on accuracy which consisted of 4 measured parameters: distance from target to needle tip, distance from planned path to needle tip, distance from midline to needle tip, and distance from the anterior 1/3 of the vertebral body to needle tip. Success within each parameter required that the distance between the needle tip and parameter being evaluated be no more than 5 mm on multiplanar CBCT or fluoroscopy. Imaging data for 12 vertebral levels was available for review. All vertebral levels were treated using unilateral access and 9 levels were treated with an extrapedicular approach. Technical success rates were 92% for both distance from planned path and distance from midline to final needle tip, 100% when distance from needle tip to the anterior 1/3 border of the vertebral body was measured, and 75% when distance from target to needle tip was measured. There were no major complications. Minor complications consisted of 3 cases (25%) of cement extravasation. C-arm CBCT with needle path overlay for fluoroscopic guided vertebroplasty is feasible and allows for reliable unilateral therapy of both lumbar and thoracic vertebral bodies. Extrapedicular approaches were performed safely and with good accuracy of reaching the targets.

The Engineer Topographic Laboratories /ETL/ hybrid optical/digital image processor

NASA Astrophysics Data System (ADS)

Benton, J. R.; Corbett, F.; Tuft, R.

1980-01-01

An optical-digital processor for generalized image enhancement and filtering is described. The optical subsystem is a two-PROM Fourier filter processor. Input imagery is isolated, scaled, and imaged onto the first PROM; this input plane acts like a liquid gate and serves as an incoherent-to-coherent converter. The image is transformed onto a second PROM which also serves as a filter medium; filters are written onto the second PROM with a laser scanner in real time. A solid state CCTV camera records the filtered image, which is then digitized and stored in a digital image processor. The operator can then manipulate the filtered image using the gray scale and color remapping capabilities of the video processor as well as the digital processing capabilities of the minicomputer.

Quantitative luminescence imaging system

DOEpatents

Erwin, D.N.; Kiel, J.L.; Batishko, C.R.; Stahl, K.A.

1990-08-14

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopic imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber. 22 figs.

Quantitative luminescence imaging system

DOEpatents

Erwin, David N.; Kiel, Johnathan L.; Batishko, Charles R.; Stahl, Kurt A.

1990-01-01

The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopie imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber.

A multimodal imaging platform with integrated simultaneous photoacoustic microscopy, optical coherence tomography, optical Doppler tomography and fluorescence microscopy

NASA Astrophysics Data System (ADS)

Dadkhah, Arash; Zhou, Jun; Yeasmin, Nusrat; Jiao, Shuliang

2018-02-01

Various optical imaging modalities with different optical contrast mechanisms have been developed over the past years. Although most of these imaging techniques are being used in many biomedical applications and researches, integration of these techniques will allow researchers to reach the full potential of these technologies. Nevertheless, combining different imaging techniques is always challenging due to the difference in optical and hardware requirements for different imaging systems. Here, we developed a multimodal optical imaging system with the capability of providing comprehensive structural, functional and molecular information of living tissue in micrometer scale. This imaging system integrates photoacoustic microscopy (PAM), optical coherence tomography (OCT), optical Doppler tomography (ODT) and fluorescence microscopy in one platform. Optical-resolution PAM (OR-PAM) provides absorption-based imaging of biological tissues. Spectral domain OCT is able to provide structural information based on the scattering property of biological sample with no need for exogenous contrast agents. In addition, ODT is a functional extension of OCT with the capability of measurement and visualization of blood flow based on the Doppler effect. Fluorescence microscopy allows to reveal molecular information of biological tissue using autofluoresce or exogenous fluorophores. In-vivo as well as ex-vivo imaging studies demonstrated the capability of our multimodal imaging system to provide comprehensive microscopic information on biological tissues. Integrating all the aforementioned imaging modalities for simultaneous multimodal imaging has promising potential for preclinical research and clinical practice in the near future.

Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

NASA Astrophysics Data System (ADS)

Liang, Shanshan; Saidi, Arya; Jing, Joe; Liu, Gangjun; Li, Jiawen; Zhang, Jun; Sun, Changsen; Narula, Jagat; Chen, Zhongping

2012-07-01

We developed a multimodality fluorescence and optical coherence tomography probe based on a double-clad fiber (DCF) combiner. The probe is composed of a DCF combiner, grin lens, and micromotor in the distal end. An integrated swept-source optical coherence tomography and fluorescence intensity imaging system was developed based on the combined probe for the early diagnoses of atherosclerosis. This system is capable of real-time data acquisition and processing as well as image display. For fluorescence imaging, the inflammation of atherosclerosis and necrotic core formed with the annexin V-conjugated Cy5.5 were imaged. Ex vivo imaging of New Zealand white rabbit arteries demonstrated the capability of the combined system.

Magneto-photo-acoustic imaging

PubMed Central

Qu, Min; Mallidi, Srivalleesha; Mehrmohammadi, Mohammad; Truby, Ryan; Homan, Kimberly; Joshi, Pratixa; Chen, Yun-Sheng; Sokolov, Konstantin; Emelianov, Stanislav

2011-01-01

Magneto-photo-acoustic imaging, a technique based on the synergy of magneto-motive ultrasound, photoacoustic and ultrasound imaging, is introduced. Hybrid nanoconstructs, liposomes encapsulating gold nanorods and iron oxide nanoparticles, were used as a dual-contrast agent for magneto-photo-acoustic imaging. Tissue-mimicking phantom and macrophage cells embedded in ex vivo porcine tissue were used to demonstrate that magneto-photo-acoustic imaging is capable of visualizing the location of cells or tissues labeled with dual-contrast nanoparticles with sufficient contrast, excellent contrast resolution and high spatial resolution in the context of the anatomical structure of the surrounding tissues. Therefore, magneto-photo-acoustic imaging is capable of identifying the nanoparticle-labeled pathological regions from the normal tissue, providing a promising platform to noninvasively diagnose and characterize pathologies. PMID:21339883

[Mobile phone-computer wireless interactive graphics transmission technology and its medical application].

PubMed

Huang, Shuo; Liu, Jing

2010-05-01

Application of clinical digital medical imaging has raised many tough issues to tackle, such as data storage, management, and information sharing. Here we investigated a mobile phone based medical image management system which is capable of achieving personal medical imaging information storage, management and comprehensive health information analysis. The technologies related to the management system spanning the wireless transmission technology, the technical capabilities of phone in mobile health care and management of mobile medical database were discussed. Taking medical infrared images transmission between phone and computer as an example, the working principle of the present system was demonstrated.

Characterization and imaging of nanostructured materials using tabletop extreme ultraviolet light sources

NASA Astrophysics Data System (ADS)

Karl, Robert; Knobloch, Joshua; Frazer, Travis; Tanksalvala, Michael; Porter, Christina; Bevis, Charles; Chao, Weilun; Abad Mayor, Begoña.; Adams, Daniel; Mancini, Giulia F.; Hernandez-Charpak, Jorge N.; Kapteyn, Henry; Murnane, Margaret

2018-03-01

Using a tabletop coherent extreme ultraviolet source, we extend current nanoscale metrology capabilities with applications spanning from new models of nanoscale transport and materials, to nanoscale device fabrication. We measure the ultrafast dynamics of acoustic waves in materials; by analyzing the material's response, we can extract elastic properties of films as thin as 11nm. We extend this capability to a spatially resolved imaging modality by using coherent diffractive imaging to image the acoustic waves in nanostructures as they propagate. This will allow for spatially resolved characterization of the elastic properties of non-isotropic materials.

Cell phones as imaging sensors

NASA Astrophysics Data System (ADS)

Bhatti, Nina; Baker, Harlyn; Marguier, Joanna; Berclaz, Jérôme; Süsstrunk, Sabine

2010-04-01

Camera phones are ubiquitous, and consumers have been adopting them faster than any other technology in modern history. When connected to a network, though, they are capable of more than just picture taking: Suddenly, they gain access to the power of the cloud. We exploit this capability by providing a series of image-based personal advisory services. These are designed to work with any handset over any cellular carrier using commonly available Multimedia Messaging Service (MMS) and Short Message Service (SMS) features. Targeted at the unsophisticated consumer, these applications must be quick and easy to use, not requiring download capabilities or preplanning. Thus, all application processing occurs in the back-end system (i.e., as a cloud service) and not on the handset itself. Presenting an image to an advisory service in the cloud, a user receives information that can be acted upon immediately. Two of our examples involve color assessment - selecting cosmetics and home décor paint palettes; the third provides the ability to extract text from a scene. In the case of the color imaging applications, we have shown that our service rivals the advice quality of experts. The result of this capability is a new paradigm for mobile interactions - image-based information services exploiting the ubiquity of camera phones.

Focused ultrasound delivery of Raman nanoparticles across the blood-brain barrier: potential for targeting experimental brain tumors.

PubMed

Diaz, Roberto Jose; McVeigh, Patrick Z; O'Reilly, Meaghan A; Burrell, Kelly; Bebenek, Matthew; Smith, Christian; Etame, Arnold B; Zadeh, Gelareh; Hynynen, Kullervo; Wilson, Brian C; Rutka, James T

2014-07-01

Spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS) capability in the near-infrared range is an emerging molecular imaging technique. We used magnetic resonance image-guided transcranial focused ultrasound (TcMRgFUS) to reversibly disrupt the blood-brain barrier (BBB) adjacent to brain tumor margins in rats. Glioma cells were found to internalize SERS capable nanoparticles of 50nm or 120nm physical diameter. Surface coating with anti-epidermal growth factor receptor antibody or non-specific human immunoglobulin G, resulted in enhanced cell uptake of nanoparticles in-vitro compared to nanoparticles with methyl terminated 12-unit polyethylene glycol surface. BBB disruption permitted the delivery of SERS capable spherical 50 or 120nm gold nanoparticles to the tumor margins. Thus, nanoparticles with SERS imaging capability can be delivered across the BBB non-invasively using TcMRgFUS and have the potential to be used as optical tracking agents at the invasive front of malignant brain tumors. This study demonstrates the use of magnetic resonance image-guided transcranial focused ultrasound to open the BBB and enable spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS)-based molecular imaging for experimental tumor tracking. Copyright © 2014 Elsevier Inc. All rights reserved.

The SIR-B science investigations plan: Introduction

NASA Technical Reports Server (NTRS)

1984-01-01

The Shuttle Imaging Radar-B (SIR-B) and its capabilities are described. The SIR-B instrument is an upgraded version of SIR-A that has the additional capability of tilting the antenna mechanically to acquire data at incidence angles that vary from 15 to 60 deg. Like SEASAT and SIR-A, SIR-B will be an L-band (23-cm) HH polarized radar. The variable-incidence-angle capability will allow several experiments. A specific area may be imaged with a variety of incidence angles on successive days. These images can then be registered and used to produce curves of backscatter as a function of incidence angle for various terrain types. These curves can be used ultimately to characterize the terrain. Stereoimaging may also be done in the multiple-incidence-angle mode. In addition, large areas may be imaged and mosaicked together with only slight variations in incidence angle with each swath.

Imaging Exoplanets with the Exo-S Starshade Mission: Baseline Design

NASA Astrophysics Data System (ADS)

Cady, Eric; Lisman, Doug; Martin, Stefan; Scharf, Daniel; Shaklan, Stuart; Trabert, Rachel; Webb, David; Exo-S Science; Technology Definition Team, Exoplanet Program Probe Study Design Team

2015-01-01

Starshades suppress on-axis starlight to enable the direct imaging of exoplanets with non-specialized space telescopes of variable size. Even relatively small, commercially available telescopes are capable of imaging Earth-like planets in the habitable zone, and larger telescopes provide the capability to characterize planet atmospheres with increasing spectral resolution. We detail two options developed by the STDT for probe-class starshade missions (Exo-S): a co-launch of a starshade with a dedicated 1.1m telescope, and a standalone starshade to augment an existing large telescope such as WFIRST-AFTA. For these concepts, we describe the optical and mechanical design, the formation flying system, and the augmentations required to make a telescope 'starshade-ready'. We also lay out typical design reference missions for each and their scientific yield, and show both concepts have the capability to image terrestrial exoplanets orbiting nearby stars.

Workshop on the Use of Future Multispectral Imaging Capabilities for Lithologic Mapping: Workshop summary

NASA Technical Reports Server (NTRS)

Settle, M.; Adams, J.

1982-01-01

Improved orbital imaging capabilities from the standpoint of different scientific disciplines, such as geology, botany, hydrology, and geography were evaluated. A discussion on how geologists might exploit the anticipated measurement capabilities of future orbital imaging systems to discriminate and characterize different types of geologic materials exposed at the Earth's surface is presented. Principle objectives are to summarize past accomplishments in the use of multispectral imaging techniques for lithologic mapping; to identify critical gaps in earlier research efforts that currently limit the ability to extract useful information about the physical and chemical characteristics of geological materials from orbital multispectral surveys; and to define major thresholds, resolution and sensitivity within the visible and infrared portions of the electromagnetic spectrum which, if achieved would result in significant improvement in our ability to discriminate and characterize different geological materials exposed at the Earth's surface.

Space Shuttle Columbia views the world with imaging radar: The SIR-A experiment

NASA Technical Reports Server (NTRS)

Ford, J. P.; Cimino, J. B.; Elachi, C.

1983-01-01

Images acquired by the Shuttle Imaging Radar (SIR-A) in November 1981, demonstrate the capability of this microwave remote sensor system to perceive and map a wide range of different surface features around the Earth. A selection of 60 scenes displays this capability with respect to Earth resources - geology, hydrology, agriculture, forest cover, ocean surface features, and prominent man-made structures. The combined area covered by the scenes presented amounts to about 3% of the total acquired. Most of the SIR-A images are accompanied by a LANDSAT multispectral scanner (MSS) or SEASAT synthetic-aperture radar (SAR) image of the same scene for comparison. Differences between the SIR-A image and its companion LANDSAT or SEASAT image at each scene are related to the characteristics of the respective imaging systems, and to seasonal or other changes that occurred in the time interval between acquisition of the images.

Image based performance analysis of thermal imagers

NASA Astrophysics Data System (ADS)

Wegner, D.; Repasi, E.

2016-05-01

Due to advances in technology, modern thermal imagers resemble sophisticated image processing systems in functionality. Advanced signal and image processing tools enclosed into the camera body extend the basic image capturing capability of thermal cameras. This happens in order to enhance the display presentation of the captured scene or specific scene details. Usually, the implemented methods are proprietary company expertise, distributed without extensive documentation. This makes the comparison of thermal imagers especially from different companies a difficult task (or at least a very time consuming/expensive task - e.g. requiring the execution of a field trial and/or an observer trial). For example, a thermal camera equipped with turbulence mitigation capability stands for such a closed system. The Fraunhofer IOSB has started to build up a system for testing thermal imagers by image based methods in the lab environment. This will extend our capability of measuring the classical IR-system parameters (e.g. MTF, MTDP, etc.) in the lab. The system is set up around the IR- scene projector, which is necessary for the thermal display (projection) of an image sequence for the IR-camera under test. The same set of thermal test sequences might be presented to every unit under test. For turbulence mitigation tests, this could be e.g. the same turbulence sequence. During system tests, gradual variation of input parameters (e. g. thermal contrast) can be applied. First ideas of test scenes selection and how to assembly an imaging suite (a set of image sequences) for the analysis of imaging thermal systems containing such black boxes in the image forming path is discussed.

Widefield quantitative multiplex surface enhanced Raman scattering imaging in vivo

NASA Astrophysics Data System (ADS)

McVeigh, Patrick Z.; Mallia, Rupananda J.; Veilleux, Israel; Wilson, Brian C.

2013-04-01

In recent years numerous studies have shown the potential advantages of molecular imaging in vitro and in vivo using contrast agents based on surface enhanced Raman scattering (SERS), however the low throughput of traditional point-scanned imaging methodologies have limited their use in biological imaging. In this work we demonstrate that direct widefield Raman imaging based on a tunable filter is capable of quantitative multiplex SERS imaging in vivo, and that this imaging is possible with acquisition times which are orders of magnitude lower than achievable with comparable point-scanned methodologies. The system, designed for small animal imaging, has a linear response from (0.01 to 100 pM), acquires typical in vivo images in <10 s, and with suitable SERS reporter molecules is capable of multiplex imaging without compensation for spectral overlap. To demonstrate the utility of widefield Raman imaging in biological applications, we show quantitative imaging of four simultaneous SERS reporter molecules in vivo with resulting probe quantification that is in excellent agreement with known quantities (R2>0.98).

Terahertz Tools Advance Imaging for Security, Industry

NASA Technical Reports Server (NTRS)

2010-01-01

Picometrix, a wholly owned subsidiary of Advanced Photonix Inc. (API), of Ann Arbor, Michigan, invented the world s first commercial terahertz system. The company improved the portability and capabilities of their systems through Small Business Innovation Research (SBIR) agreements with Langley Research Center to provide terahertz imaging capabilities for inspecting the space shuttle external tanks and orbiters. Now API s systems make use of the unique imaging capacity of terahertz radiation on manufacturing floors, for thickness measurements of coatings, pharmaceutical tablet production, and even art conservation.

Supercritical Catalytic Cracking of Hydrocarbon Feeds Insight

DTIC Science & Technology

2016-04-21

University teamed with Spectral Energies, LLC to develop appropriate spatiotemporal imaging capabilities in single body zeolites to describe beneficial...We demonstrated the ability to follow in a spatiotemporal fashion, the decomposition of the structure-directing agent used to template the zeolite ...appropriate spatiotemporal imaging capabilities in single body zeolites to describe beneficial and parasitic catalytic cracking pathways. Beneficial

PDSS/IMC requirements and functional specifications

NASA Technical Reports Server (NTRS)

1983-01-01

The system (software and hardware) requirements for the Payload Development Support System (PDSS)/Image Motion Compensator (IMC) are provided. The PDSS/IMC system provides the capability for performing Image Motion Compensator Electronics (IMCE) flight software test, checkout, and verification and provides the capability for monitoring the IMC flight computer system during qualification testing for fault detection and fault isolation.

Light Microscopy Module (LMM)-Emulator

NASA Technical Reports Server (NTRS)

Levine, Howard G.; Smith, Trent M.; Richards, Stephanie E.

2016-01-01

The Light Microscopy Module (LMM) is a microscope facility developed at Glenn Research Center (GRC) that provides researchers with powerful imaging capability onboard the International Space Station (ISS). LMM has the ability to have its hardware recongured on-orbit to accommodate a wide variety of investigations, with the capability of remotely acquiring and downloading digital images across multiple levels of magnication.

New Regimes of Implosions of Larger Sized Wire Arrays With and Without Modified Central Plane at 1.5-1.7 MA Zebra

NASA Astrophysics Data System (ADS)

Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.; Weller, M. E.; Shrestha, I.; Shlyaptseva, V. V.; Stafford, A.; Keim, S. F.; Petkov, E. E.; Lorance, M.; Chuvatin, A. S.; Coverdale, C. A.; Jones, B.

2013-10-01

The recent experiments at 1.5-1.7 MA on Zebra at UNR with larger sized planar wires arrays (compared to the wire loads at 1 MA current) have demonstrated higher linear radiation yield and electron temperatures as well as advantages of better diagnostics access to observable plasma regions. Such multi-planar wire arrays had two outer wire planes from mid-Z material to create a global magnetic field (gmf) and mid-Z plasma flow between them. Also, they included a modified central plane with a few Al wires at the edges to influence gmf and to create Al plasma flow in the perpendicular direction. The stationary shock waves which existed over tens of ns on shadow images and the early x-ray emissions before the PCD peak on time-gated spectra were observed. The most recent experiments with similar loads but without the central wires demonstrated a very different regime of implosion with asymmetrical jets and no precursor formation. This work was supported by NNSA under DOE Cooperative Agreement DE-NA0001984 and in part by DE-FC52-06NA27616. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

Preoperative localization of Adamkiewicz arteries and their origins by using MDCT angiography.

PubMed

Sukeeyamanon, Wiwithawan; Siriapisith, Thanongchai; Wasinrat, Jitladda

2010-12-01

To evaluate the ability of thoraco-abdominal MDCT angiography to visualize Adamkiewicz arteries for preoperative planning in patients diagnosed with aortic disease. The present study retrospectively reviewed clinical data from 73 patients who underwent a thoraco-abdominal 64-slice MDCT angiography. The Adamkiewicz artery was evaluated on multiplanar reformation images in each case. The visualization of the Adamkiewicz artery, level of origin, side of origin and continuation from an intercostal artery was investigated. The Adamkiewicz arteries were visualized in 52 of the 73 patients (71.2%), and the total number of the delineated Adamkiewicz arteries was 64. Two Adamkiewicz arteries were found in nine patients (17.3%). Four Adamkiewicz arteries were found in one patient (1.9%). Most of the delineated arteries arose from the T9-L2 levels (89.1%). A left side of origin was found in 41 of 64 arteries (64.1%), and a right side of origin was found in 23 of 64 arteries (35.9%). Only 12 of 64 delineated arteries (18.8%) showed continuity from their origins to the anterior radiculomedullary artery. The preoperative detection rate of the Adamkiewicz artery with the routine technique of 64-slice MDCT angiography was 71.2%. The preoperative location of the Adamkiewicz artery may help to reduce the risk of perioperative ischemic changes in the spinal cord.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Streitparth, F., E-mail: florian.streitparth@charite.de; Walter, A.; Stolzenburg, N.

Purpose. To evaluate the feasibility and efficacy of image-guided periarterial ethanol injection as an alternative to transluminal radiofrequency ablation. Methods. Unilateral renal periarterial ethanol injection was performed under general anesthesia in 6 pigs with the contralateral kidney serving as control. All interventions were performed in an open 1.0 T MRI system under real-time multiplanar guidance. The injected volume was 5 ml (95 % ethanol labelled marked MR contrast medium) in 2 pigs and 10 ml in 4 pigs. Four weeks after treatment, the pigs underwent MRI including MRA and were killed. Norepinephrine (NE) concentration in the renal parenchyma served asmore » a surrogate parameter to analyze the efficacy of sympathetic denervation. In addition, the renal artery and sympathetic nerves were examined histologically to identify evidence of vascular and neural injury. Results. In pigs treated with 10 ml ethanol, treatment resulted in neural degeneration. We found a significant reduction of NE concentration in the kidney parenchyma of 53 % (p < 0.02) compared with the untreated contralateral kidney. In pigs treated with 5 ml ethanol, no significant changes in histology or NE were observed. There was no evidence of renal arterial stenosis in MRI, macroscopy or histology in any pig. Conclusion. MR-guided periarterial ethanol injection was feasible and efficient for renal sympathetic denervation in a swine model. This technique may be a promising alternative to the catheter-based approach in the treatment of resistant arterial hypertension.« less

A stress MRI of the shoulder for evaluation of ligamentous stabilizers in acute and chronic acromioclavicular joint instabilities.

PubMed

Izadpanah, Kaywan; Winterer, Jan; Vicari, Marco; Jaeger, Martin; Maier, Dirk; Eisebraun, Leonie; Ute Will, Jutta; Kotter, Elmar; Langer, Mathias; Südkamp, Norbert P; Hennig, Jürgen; Weigel, Mathias

2013-06-01

To show the feasibility of a stress magnetic resonance imaging (MRI) as a new method for simultaneous evaluation of the morphology and the functional integrity of the acromioclavicular joint (ACJ) ligamentous stabilizers. MRI of four volunteers, 10 patients with acute, and six with chronic ACJ injuries was performed using a 0.25 T open MRI scanner. A 2D-proton-density and a 3D-gradient-echo sequence at rest and under 6.5 kg shoulder traction were performed. Comparative measurements of the coracoclavicular and the acromioclavicular distance were performed. Additionally, the conoid and trapezoid ligament lengths were measured with multiplanar reconstructions. MRI at rest correctly identified tears of the coracoclavicular and the acromioclavicular ligaments in eight patients suffering acute ACJ injuries. Stress application helped to distinguish between partial and complete coracoclavicular ligament tears in two cases. Insufficiency of the ACJ ligaments was present in all acute and chronic ACJ injuries. Stress application in chronic ACJ ligaments revealed isolated insufficiency of the conoid ligament in three cases and of the trapezoid ligament in one case. Combined insufficiency was present in two cases. Stress MRI facilitates simultaneous acquisition of morphologic and functional information of the ACJ stabilizers. In acute ACJ injuries it helps to distinguish between partial and complete ligament tears. In chronic ACJ injuries it provides functional information of the ligament regrinds. Copyright © 2012 Wiley Periodicals, Inc.

Vena Cava 3D Contrast-Enhanced MR Venography: A Pictorial Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin Jiang; Zhou Kangrong; Chen Zuwang

Three-dimensional contrast-enhanced magnetic resonance venography (CE MRV) is a sensitive and accurate method for diagnosing vena cava pathologies. The commonly used indirect approach involves a nondiluted gadolinium contrast agent injected into an upper limb vein or, occasionally, a pedal vein for assessment of the superior or inferior vena cava. In our studies, a coronal 3D fast multi-planar spoiled gradient-echo acquisition was used. A pre-contrast scan was obtained to ensure correct coverage of the region of interest. We initiated contrast-enhanced acquisition 15 sec after the start of contrast agent injection and performed the procedure twice. The image sets were obtained duringmore » two 20-30-sec breath hold, with a breathing rest of 5-6 sec, to obtain the first-pass and delayed arteriovenous phases. For patients with Budd-Chiari syndrome, a third acquisition coinciding with late venous phase was collected to visualize the hepatic veins, which was carried out by one additional acquisition after a 5-6-sec breathing time. This review describes the clinical application of 3D CE MRV in vena cava congenital anomalies, superior and inferior vena cava syndrome, Budd-Chiari syndrome, peripheral vein thrombosis extending to the vena cava, pre-operational evaluation in portosystemic shunting and post-surgical follow-up, and road-mapping for the placement and evaluation of complications of central venous devices.« less

Cranial sutures and craniometric points detected on MRI.

PubMed

Cotton, François; Rozzi, Fernando Ramirez; Vallee, Bernard; Pachai, Chahin; Hermier, Marc; Guihard-Costa, Anne-Marie; Froment, Jean-Claude

2005-03-01

The main goal of the study was to determine on MRI the cranial sutures, the craniometric points and craniometric measurements, and to correlate these results with classical anthropometric measurements. For this purpose, we reviewed 150 cerebral MRI examinations considered as normal (Caucasian population aged 20-49 years). For each examination we individualized 11 craniometric landmarks (Glabella, Bregma, Lambda, Opisthocranion, Opisthion, Basion, Inion, Porion, Infra-orbital, Eurion) and three measurements. Measurements were also calculated independently on 498 dry crania (Microscribe 3-DX digitizer). To validate the MRI procedure, we measured four dry crania by MRI and with compass or digital caliper gauges. Cranial sutures always appeared without signal (black), whatever the MRI sequence used, and they are better visualized with a 5 mm slice thickness (compact bone overlapping). Slice dynamic analysis and multiplanar reformatting allowed the detection of all craniometric points, some of these being more difficult to detect than others (Porion, Infra-orbital). The measurements determined by these points were as follows: Vertex-Basion height=135.66+/-6.56 mm; Eurion-Eurion width=141.17+/-5.19 mm; Glabella-Opisthocranion length=181.94+/-6.40 mm. On the midline T1-weighted sagittal image, all median craniometric landmarks can be individualized and the Glabella-Opisthocranion length, Vertex-Basion height and parenchyma indices can be calculated. Craniometric points and measurements between these points can be estimated with a standard cerebral MRI examination, with results that are similar to anthropometric data.

Ultrasound virtual endoscopy: Polyp detection and reliability of measurement in an in vitro study with pig intestine specimens

PubMed Central

Liu, Jin-Ya; Chen, Li-Da; Cai, Hua-Song; Liang, Jin-Yu; Xu, Ming; Huang, Yang; Li, Wei; Feng, Shi-Ting; Xie, Xiao-Yan; Lu, Ming-De; Wang, Wei

2016-01-01

AIM: To present our initial experience regarding the feasibility of ultrasound virtual endoscopy (USVE) and its measurement reliability for polyp detection in an in vitro study using pig intestine specimens. METHODS: Six porcine intestine specimens containing 30 synthetic polyps underwent USVE, computed tomography colonography (CTC) and optical colonoscopy (OC) for polyp detection. The polyp measurement defined as the maximum polyp diameter on two-dimensional (2D) multiplanar reformatted (MPR) planes was obtained by USVE, and the absolute measurement error was analyzed using the direct measurement as the reference standard. RESULTS: USVE detected 29 (96.7%) of 30 polyps, remaining a 7-mm one missed. There was one false-positive finding. Twenty-six (89.7%) of 29 reconstructed images were clearly depicted, while 29 (96.7%) of 30 polyps were displayed on CTC with one false-negative finding. In OC, all the polyps were detected. The intraclass correlation coefficient was 0.876 (95%CI: 0.745-0.940) for measurements obtained with USVE. The pooled absolute measurement errors ± the standard deviations of the depicted polyps with actual sizes ≤ 5 mm, 6-9 mm, and ≥ 10 mm were 1.9 ± 0.8 mm, 0.9 ± 1.2 mm, and 1.0 ± 1.4 mm, respectively. CONCLUSION: USVE is reliable for polyp detection and measurement in in vitro study. PMID:27022217

Quantitative evaluation of maxillary bone deformation by computed tomography in patients with leprosy

PubMed Central

Kondo, Osamu; Suzuki, Koichi; Aoki, Yoshinori; Ishii, Norihisa

2018-01-01

Background Facial deformation as a sequela of leprosy is caused not only by a saddle nose but also by regression of the maxilla, as well documented in paleopathological observations of excavated skeletal remains of patients with leprosy. However, maxillary changes in living patients have been evaluated only by the subjective visual grading. Here, we attempted to evaluate maxillary bone deformation in patients with leprosy using three-dimensional computed tomography (3D-CT). Methods Three-dimensional images centered on the maxilla were reconstructed using multiplanar reconstruction methods in former patients with leprosy (n = 10) and control subjects (n = 5); the anterior-posterior length of the maxilla (MA-P) was then measured. The difference between the MA-P of the patients and those of controls was evaluated after compensating for individual skull size. These findings were also compared with those from previous paleopathological studies. Findings Three former patients with lepromatous leprosy showed marked atrophy of the maxilla at the prosthion (-8.6, -11.1 and -17.9 mm) which corresponded with the visual appearance of the maxillary deformity, and these results were consistent with paleopathological findings of excavated skeletal remains. Additionally, the precise bone defects of the maxilla could be individually calculated for accurate reconstructive surgery. Interpretation We have successfully illustrated maxillary bone deformities in living patients with leprosy. This study also confirmed the maxillary regression described in paleopathological studies. PMID:29522533

Clinical feasibility and validation of 3D principal strain analysis from cine MRI: comparison to 2D strain by MRI and 3D speckle tracking echocardiography.

PubMed

Satriano, Alessandro; Heydari, Bobak; Narous, Mariam; Exner, Derek V; Mikami, Yoko; Attwood, Monica M; Tyberg, John V; Lydell, Carmen P; Howarth, Andrew G; Fine, Nowell M; White, James A

2017-12-01

Two-dimensional (2D) strain analysis is constrained by geometry-dependent reference directions of deformation (i.e. radial, circumferential, and longitudinal) following the assumption of cylindrical chamber architecture. Three-dimensional (3D) principal strain analysis may overcome such limitations by referencing intrinsic (i.e. principal) directions of deformation. This study aimed to demonstrate clinical feasibility of 3D principal strain analysis from routine 2D cine MRI with validation to strain from 2D tagged cine analysis and 3D speckle tracking echocardiography. Thirty-one patients undergoing cardiac MRI were studied. 3D strain was measured from routine, multi-planar 2D cine SSFP images using custom software designed to apply 4D deformation fields to 3D cardiac models to derive principal strain. Comparisons of strain estimates versus those by 2D tagged cine, 2D non-tagged cine (feature tracking), and 3D speckle tracking echocardiography (STE) were performed. Mean age was 51 ± 14 (36% female). Mean LV ejection fraction was 66 ± 10% (range 37-80%). 3D principal strain analysis was feasible in all subjects and showed high inter- and intra-observer reproducibility (ICC range 0.83-0.97 and 0.83-0.98, respectively-p < 0.001 for all directions). Strong correlations of minimum and maximum principal strain were respectively observed versus the following: 3D STE estimates of longitudinal (r = 0.81 and r = -0.64), circumferential (r = 0.76 and r = -0.58) and radial (r = -0.80 and r = 0.63) strain (p < 0.001 for all); 2D tagged cine estimates of longitudinal (r = 0.81 and r = -0.81), circumferential (r = 0.87 and r = -0.85), and radial (r = -0.76 and r = 0.81) strain (p < 0.0001 for all); and 2D cine (feature tracking) estimates of longitudinal (r = 0.85 and -0.83), circumferential (r = 0.88 and r = -0.87), and radial strain (r = -0.79 and r = 0.84, p < 0.0001 for all). 3D principal strain analysis is feasible using routine, multi-planar 2D cine MRI and shows high reproducibility with strong correlations to 2D conventional strain analysis and 3D STE-based analysis. Given its independence from geometry-related directions of deformation this technique may offer unique benefit for the detection and prognostication of myocardial disease, and warrants expanded investigation.

The NN-explore Exoplanet Stellar Speckle Imager: Instrument Description and Preliminary Results

NASA Astrophysics Data System (ADS)

Scott, Nicholas J.; Howell, Steve B.; Horch, Elliott P.; Everett, Mark E.

2018-05-01

A new speckle and wide-field imaging instrument for the WIYN telescope called NN-EXPLORE Exoplanet Stellar Speckle Imager (NESSI) is described. NESSI offers simultaneous two-color diffraction-limited imaging and wide-field traditional imaging for validation and characterization of transit and precision RV exoplanet studies. Many exoplanet targets will come from the NASA K2 and Transiting Exoplanet Survey Satellite (TESS) missions. NESSI is capable of resolving close binaries at sub-arcsecond separations down to the diffraction limit and >6 mag contrast difference in the visible band on targets as faint as 14th mag. Preliminary results from the instrument commissioning at WIYN and demonstrations of the instrument’s capabilities are presented.

Application and Miniaturization of Linear and Nonlinear Raman Microscopy for Biomedical Imaging

NASA Astrophysics Data System (ADS)

Mittal, Richa

Current diagnostics for several disorders rely on surgical biopsy or evaluation of ex vivo bodily fluids, which have numerous drawbacks. We evaluated the potential for vibrational techniques (both linear and nonlinear Raman) as a reliable and noninvasive diagnostic tool. Raman spectroscopy is an optical technique for molecular analysis that has been used extensively in various biomedical applications. Based on demonstrated capabilities of Raman spectroscopy we evaluated the potential of the technique for providing a noninvasive diagnosis of mucopolysaccharidosis (MPS). These studies show that Raman spectroscopy can detect subtle changes in tissue biochemistry. In applications where sub-micrometer visualization of tissue compositional change is required, a transition from spectroscopy to high quality imaging is necessary. Nonlinear vibrational microscopy is sensitive to the same molecular vibrations as linear Raman, but features fast imaging capabilities. Coherent Raman scattering when combined with other nonlinear optical (NLO) techniques (like two-photon excited fluorescence and second harmonic generation) forms a collection of advanced optical techniques that provide noninvasive chemical contrast at submicron resolution. This capability to examine tissues without external molecular agents is driving the NLO approach towards clinical applications. However, the unique imaging capabilities of NLO microscopy are accompanied by complex instrument requirements. Clinical examination requires portable imaging systems for rapid inspection of tissues. Optical components utilized in NLO microscopy would then need substantial miniaturization and optimization to enable in vivo use. The challenges in designing compact microscope objective lenses and laser beam scanning mechanisms are discussed. The development of multimodal NLO probes for imaging oral cavity tissue is presented. Our prototype has been examined for ex vivo tissue imaging based on intrinsic fluorescence and SHG contrast. These studies show a potential for multiphoton compact probes to be used for real time imaging in the clinic.

Unprocessed real-time imaging of vitreoretinal surgical maneuvers using a microscope-integrated spectral-domain optical coherence tomography system.

PubMed

Hahn, Paul; Migacz, Justin; O'Connell, Rachelle; Izatt, Joseph A; Toth, Cynthia A

2013-01-01

We have recently developed a microscope-integrated spectral-domain optical coherence tomography (MIOCT) device towards intrasurgical cross-sectional imaging of surgical maneuvers. In this report, we explore the capability of MIOCT to acquire real-time video imaging of vitreoretinal surgical maneuvers without post-processing modifications. Standard 3-port vitrectomy was performed in human during scheduled surgery as well as in cadaveric porcine eyes. MIOCT imaging of human subjects was performed in healthy normal volunteers and intraoperatively at a normal pause immediately following surgical manipulations, under an Institutional Review Board-approved protocol, with informed consent from all subjects. Video MIOCT imaging of live surgical manipulations was performed in cadaveric porcine eyes by carefully aligning B-scans with instrument orientation and movement. Inverted imaging was performed by lengthening of the reference arm to a position beyond the choroid. Unprocessed MIOCT imaging was successfully obtained in healthy human volunteers and in human patients undergoing surgery, with visualization of post-surgical changes in unprocessed single B-scans. Real-time, unprocessed MIOCT video imaging was successfully obtained in cadaveric porcine eyes during brushing of the retina with the Tano scraper, peeling of superficial retinal tissue with intraocular forceps, and separation of the posterior hyaloid face. Real-time inverted imaging enabled imaging without complex conjugate artifacts. MIOCT is capable of unprocessed imaging of the macula in human patients undergoing surgery and of unprocessed, real-time, video imaging of surgical maneuvers in model eyes. These capabilities represent an important step towards development of MIOCT for efficient, real-time imaging of manipulations during human surgery.

Parallel-multiplexed excitation light-sheet microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Xu, Dongli; Zhou, Weibin; Peng, Leilei

2017-02-01

Laser scanning light-sheet imaging allows fast 3D image of live samples with minimal bleach and photo-toxicity. Existing light-sheet techniques have very limited capability in multi-label imaging. Hyper-spectral imaging is needed to unmix commonly used fluorescent proteins with large spectral overlaps. However, the challenge is how to perform hyper-spectral imaging without sacrificing the image speed, so that dynamic and complex events can be captured live. We report wavelength-encoded structured illumination light sheet imaging (λ-SIM light-sheet), a novel light-sheet technique that is capable of parallel multiplexing in multiple excitation-emission spectral channels. λ-SIM light-sheet captures images of all possible excitation-emission channels in true parallel. It does not require compromising the imaging speed and is capable of distinguish labels by both excitation and emission spectral properties, which facilitates unmixing fluorescent labels with overlapping spectral peaks and will allow more labels being used together. We build a hyper-spectral light-sheet microscope that combined λ-SIM with an extended field of view through Bessel beam illumination. The system has a 250-micron-wide field of view and confocal level resolution. The microscope, equipped with multiple laser lines and an unlimited number of spectral channels, can potentially image up to 6 commonly used fluorescent proteins from blue to red. Results from in vivo imaging of live zebrafish embryos expressing various genetic markers and sensors will be shown. Hyper-spectral images from λ-SIM light-sheet will allow multiplexed and dynamic functional imaging in live tissue and animals.

Large image microscope array for the compilation of multimodality whole organ image databases.

PubMed

Namati, Eman; De Ryk, Jessica; Thiesse, Jacqueline; Towfic, Zaid; Hoffman, Eric; Mclennan, Geoffrey

2007-11-01

Three-dimensional, structural and functional digital image databases have many applications in education, research, and clinical medicine. However, to date, apart from cryosectioning, there have been no reliable means to obtain whole-organ, spatially conserving histology. Our aim was to generate a system capable of acquiring high-resolution images, featuring microscopic detail that could still be spatially correlated to the whole organ. To fulfill these objectives required the construction of a system physically capable of creating very fine whole-organ sections and collecting high-magnification and resolution digital images. We therefore designed a large image microscope array (LIMA) to serially section and image entire unembedded organs while maintaining the structural integrity of the tissue. The LIMA consists of several integrated components: a novel large-blade vibrating microtome, a 1.3 megapixel peltier cooled charge-coupled device camera, a high-magnification microscope, and a three axis gantry above the microtome. A custom control program was developed to automate the entire sectioning and automated raster-scan imaging sequence. The system is capable of sectioning unembedded soft tissue down to a thickness of 40 microm at specimen dimensions of 200 x 300 mm to a total depth of 350 mm. The LIMA system has been tested on fixed lung from sheep and mice, resulting in large high-quality image data sets, with minimal distinguishable disturbance in the delicate alveolar structures. Copyright 2007 Wiley-Liss, Inc.

Fusion Rate and Clinical Outcomes in Two-Level Posterior Lumbar Interbody Fusion.

PubMed

Aono, Hiroyuki; Takenaka, Shota; Nagamoto, Yukitaka; Tobimatsu, Hidekazu; Yamashita, Tomoya; Furuya, Masayuki; Iwasaki, Motoki

2018-04-01

Posterior lumbar interbody fusion (PLIF) has become a general surgical method for degenerative lumbar diseases. Although many reports have focused on single-level PLIF, few have focused on 2-level PLIF, and no report has covered the fusion status of 2-level PLIF. The purpose of this study is to investigate clinical outcomes and fusion for 2-level PLIF by using a combination of dynamic radiographs and multiplanar-reconstruction computed tomography scans. This study consisted of 48 consecutive patients who underwent 2-level PLIF for degenerative lumbar diseases. We assessed surgery duration, estimated blood loss, complications, clinical outcomes as measured by the Japanese Orthopaedic Association score, lumbar sagittal alignment as measured on standing lateral radiographs, and fusion status as measured by dynamic radiographs and multiplanar-reconstruction computed tomography. Patients were examined at a follow-up point of 4.8 ± 2.2 years after surgery. Thirty-eight patients who did not undergo lumbosacral fusion comprised the lumbolumbar group, and 10 patients who underwent lumbosacral fusion comprised the lumbosacral group. The mean Japanese Orthopaedic Association score improved from 12.1 to 22.4 points by the final follow-up examination. Sagittal alignment also was improved. All patients had fusion in the cranial level. Seven patients had nonunion in the caudal level, and the lumbosacral group (40%) had a significantly poorer fusion rate than the lumbolumbar group (97%) did. Surgical outcomes of 2-level PLIF were satisfactory. The fusion rate at both levels was 85%. All nonunion was observed at the caudal level and concentrated at L5-S level in L4-5-S PLIF. Copyright © 2018 Elsevier Inc. All rights reserved.

Digital image processing of bone - Problems and potentials

NASA Technical Reports Server (NTRS)

Morey, E. R.; Wronski, T. J.

1980-01-01

The development of a digital image processing system for bone histomorphometry and fluorescent marker monitoring is discussed. The system in question is capable of making measurements of UV or light microscope features on a video screen with either video or computer-generated images, and comprises a microscope, low-light-level video camera, video digitizer and display terminal, color monitor, and PDP 11/34 computer. Capabilities demonstrated in the analysis of an undecalcified rat tibia include the measurement of perimeter and total bone area, and the generation of microscope images, false color images, digitized images and contoured images for further analysis. Software development will be based on an existing software library, specifically the mini-VICAR system developed at JPL. It is noted that the potentials of the system in terms of speed and reliability far exceed any problems associated with hardware and software development.

Security protection of DICOM medical images using dual-layer reversible watermarking with tamper detection capability.

PubMed

Tan, Chun Kiat; Ng, Jason Changwei; Xu, Xiaotian; Poh, Chueh Loo; Guan, Yong Liang; Sheah, Kenneth

2011-06-01

Teleradiology applications and universal availability of patient records using web-based technology are rapidly gaining importance. Consequently, digital medical image security has become an important issue when images and their pertinent patient information are transmitted across public networks, such as the Internet. Health mandates such as the Health Insurance Portability and Accountability Act require healthcare providers to adhere to security measures in order to protect sensitive patient information. This paper presents a fully reversible, dual-layer watermarking scheme with tamper detection capability for medical images. The scheme utilizes concepts of public-key cryptography and reversible data-hiding technique. The scheme was tested using medical images in DICOM format. The results show that the scheme is able to ensure image authenticity and integrity, and to locate tampered regions in the images.

Pulsed Magneto-motive Ultrasound Imaging Using Ultrasmall Magnetic Nanoprobes

PubMed Central

Mehrmohammadi, Mohammad; Oh, Junghwan; Mallidi, Srivalleesha; Emelianov, Stanislav Y.

2011-01-01

Nano-sized particles are widely regarded as a tool to study biologic events at the cellular and molecular levels. However, only some imaging modalities can visualize interaction between nanoparticles and living cells. We present a new technique, pulsed magneto-motive ultrasound imaging, which is capable of in vivo imaging of magnetic nanoparticles in real time and at sufficient depth. In pulsed magneto-motive ultrasound imaging, an external high-strength pulsed magnetic field is applied to induce the motion within the magnetically labeled tissue and ultrasound is used to detect the induced internal tissue motion. Our experiments demonstrated a sufficient contrast between normal and iron-laden cells labeled with ultrasmall magnetic nanoparticles. Therefore, pulsed magneto-motive ultrasound imaging could become an imaging tool capable of detecting magnetic nanoparticles and characterizing the cellular and molecular composition of deep-lying structures. PMID:21439255

Perspective: Advanced particle imaging

DOE PAGES

Chandler, David W.; Houston, Paul L.; Parker, David H.

2017-05-26

This study discuss, the first ion imaging experiment demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variancemore » and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable “complete” experiments—the holy grail of molecular dynamics—where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control.« less

James Bay

Atmospheric Science Data Center

2013-04-17

...     View Larger Image The first images taken by NASA's Multi-angle Imaging ... many of MISR's new and unique capabilities," said Dr. David J. Diner, MISR principal investigator of NASA's Jet Propulsion Laboratory, ...

MRI-guided fluorescence tomography of the breast: a phantom study

NASA Astrophysics Data System (ADS)

Davis, Scott C.; Pogue, Brian W.; Dehghani, Hamid; Paulsen, Keith D.

2009-02-01

Tissue phantoms simulating the human breast were used to demonstrate the imaging capabilities of an MRI-coupled fluorescence molecular tomography (FMT) imaging system. Specifically, phantoms with low tumor-to-normal drug contrast and complex internal structure were imaged with the MR-coupled FMT system. Images of indocyanine green (ICG) fluorescence yield were recovered using a diffusion model-based approach capable of estimating the distribution of fluorescence activity in a tissue volume from tissue-boundary measurements of transmitted light. Tissue structural information, which can be determined from standard T1 and T2 MR images, was used to guide the recovery of fluorescence activity. The study revealed that this spatial guidance is critical for recovering images of fluorescence yield in tissue with low tumor-to-normal drug contrast.

White-Light Optical Information Processing and Holography.

DTIC Science & Technology

1983-05-03

Processing, White-Light Holography, Image Subtraction, Image Deblurring , Coherence Requirement, Apparent Transfer Function, Source Encoding, Signal...in this period, also demonstrated several color image processing capabilities. Among those are broadband color image deblurring and color image...Broadband Image Deblurring ..... ......... 6 2.5 Color Image Subtraction ............... 7 2.6 Rainbow Holographic Aberrations . . ..... 7 2.7

Development of an imaging system for the detection of alumina on turbine blades

NASA Astrophysics Data System (ADS)

Greenwell, S. J.; Kell, J.; Day, J. C. C.

2014-03-01

An imaging system capable of detecting alumina on turbine blades by acquiring LED-induced fluorescence images has been developed. Acquiring fluorescence images at adjacent spectral bands allows the system to distinguish alumina from fluorescent surface contaminants. Repair and overhaul processes require that alumina is entirely removed from the blades by grit blasting and chemical stripping. The capability of the system to detect alumina has been investigated with two series of turbine blades provided by Rolls-Royce plc. The results illustrate that the system provides a superior inspection method to visual assessment when ascertaining whether alumina is present on turbine blades during repair and overhaul processes.

PScan 1.0: flexible software framework for polygon based multiphoton microscopy

NASA Astrophysics Data System (ADS)

Li, Yongxiao; Lee, Woei Ming

2016-12-01

Multiphoton laser scanning microscopes exhibit highly localized nonlinear optical excitation and are powerful instruments for in-vivo deep tissue imaging. Customized multiphoton microscopy has a significantly superior performance for in-vivo imaging because of precise control over the scanning and detection system. To date, there have been several flexible software platforms catered to custom built microscopy systems i.e. ScanImage, HelioScan, MicroManager, that perform at imaging speeds of 30-100fps. In this paper, we describe a flexible software framework for high speed imaging systems capable of operating from 5 fps to 1600 fps. The software is based on the MATLAB image processing toolbox. It has the capability to communicate directly with a high performing imaging card (Matrox Solios eA/XA), thus retaining high speed acquisition. The program is also designed to communicate with LabVIEW and Fiji for instrument control and image processing. Pscan 1.0 can handle high imaging rates and contains sufficient flexibility for users to adapt to their high speed imaging systems.

Optical coherence tomography in differential diagnosis of skin pathology

NASA Astrophysics Data System (ADS)

Gladkova, Natalia D.; Petrova, Galina P.; Derpaluk, Elena; Nikulin, Nikolai K.; Snopova, Ludmila; Chumakov, Yuri; Feldchtein, Felix I.; Gelikonov, Valentin M.; Gelikonov, Grigory V.; Kuranov, Roman V.

2000-05-01

The capabilities of optical coherence tomography (OCT) for imaging in vivo of optical patterns of pathomorphological processes in the skin and use of their optical patterns in clinical practice for differential diagnosis of dermatoses are presented. Images of skin tissue 0.8 - 1.5 mm deep were acquired with a resolution of 5, 12 and 20 micrometer using three compact fiber OCT devices developed at the Institute of Applied Physics RAS. The acquisition time of images of skin regions 2 - 6 mm in length was 2 - 4 s. The OCT capabilities were analyzed based on the study of 50 patients with different dermatoses. OCT images were interpreted by comparing with parallel histology. It is shown that OCT can detect in vivo optical patterns of morphological alterations in such general papulous dermatoses as lichen ruber planus and psoriasis, a capability that can be used in differential diagnosis of these diseases. Most informative are OCT images obtained with a resolution of 5 micrometer. The results of our study demonstrate the practical importance of OCT imaging for diagnosis of different dermatoses. OCT is noninvasive and, therefore, makes it possible to perform frequent multifocal examination of skin without any adverse effects.

Magnetic resonance imaging-compatible tactile sensing device based on a piezoelectric array.

PubMed

Hamed, Abbi; Masamune, Ken; Tse, Zion Tsz Ho; Lamperth, Michael; Dohi, Takeyoshi

2012-07-01

Minimally invasive surgery is a widely used medical technique, one of the drawbacks of which is the loss of direct sense of touch during the operation. Palpation is the use of fingertips to explore and make fast assessments of tissue morphology. Although technologies are developed to equip minimally invasive surgery tools with haptic feedback capabilities, the majority focus on tissue stiffness profiling and tool-tissue interaction force measurement. For greatly increased diagnostic capability, a magnetic resonance imaging-compatible tactile sensor design is proposed, which allows minimally invasive surgery to be performed under image guidance, combining the strong capability of magnetic resonance imaging soft tissue and intuitive palpation. The sensing unit is based on a piezoelectric sensor methodology, which conforms to the stringent mechanical and electrical design requirements imposed by the magnetic resonance environment The sensor mechanical design and the device integration to a 0.2 Tesla open magnetic resonance imaging scanner are described, together with the device's magnetic resonance compatibility testing. Its design limitations and potential future improvements are also discussed. A tactile sensing unit based on a piezoelectric sensor principle is proposed, which is designed for magnetic resonance imaging guided interventions.

Focused ultrasound delivery of Raman nanoparticles across the blood-brain barrier: Potential for targeting experimental brain tumors

PubMed Central

Diaz, Roberto Jose; McVeigh, Patrick Z.; O’Reilly, Meaghan A.; Burrell, Kelly; Bebenek, Matthew; Smith, Christian; Etame, Arnold; Zadeh, Gelareh; Hynynen, Kullervo; Wilson, Brian C.; Rutka, James T.

2014-01-01

Spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS) capability in the near-infrared range is an emerging molecular imaging technique. We used magnetic resonance image-guided transcranial focused ultrasound (TcMRgFUS) to reversibly disrupt the blood-brain barrier (BBB) adjacent to brain tumor margins in rats. Glioma cells were found to internalize SERS capable nanoparticles of 50 nm or 120 nm physical diameter. Surface coating with anti-epidermal growth factor receptor antibody or non-specific human immunoglobulin G, resulted in enhanced cell uptake of nanoparticles in-vitro compared to nanoparticles with methyl terminated 12-unit polyethylene glycol surface. BBB disruption permitted the delivery of SERS capable spherical 50 or 120 nm gold nanoparticles to the tumor margins. Thus, nanoparticles with SERS imaging capability can be delivered across the BBB non-invasively using TcMRgFUS and have the potential to be used as optical tracking agents at the invasive front of malignant brain tumors. PMID:24374363

Reconfigurable metasurface aperture for security screening and microwave imaging

NASA Astrophysics Data System (ADS)

Sleasman, Timothy; Imani, Mohammadreza F.; Boyarsky, Michael; Pulido-Mancera, Laura; Reynolds, Matthew S.; Smith, David R.

2017-05-01

Microwave imaging systems have seen growing interest in recent decades for applications ranging from security screening to space/earth observation. However, hardware architectures commonly used for this purpose have not seen drastic changes. With the advent of metamaterials a wealth of opportunities have emerged for honing metasurface apertures for microwave imaging systems. Recent thrusts have introduced dynamic reconfigurability directly into the aperture layer, providing powerful capabilities from a physical layer with considerable simplicity. The waveforms generated from such dynamic metasurfaces make them suitable for application in synthetic aperture radar (SAR) and, more generally, computational imaging. In this paper, we investigate a dynamic metasurface aperture capable of performing microwave imaging in the K-band (17.5-26.5 GHz). The proposed aperture is planar and promises an inexpensive fabrication process via printed circuit board techniques. These traits are further augmented by the tunability of dynamic metasurfaces, which provides the dexterity necessary to generate field patterns ranging from a sequence of steered beams to a series of uncorrelated radiation patterns. Imaging is experimentally demonstrated with a voltage-tunable metasurface aperture. We also demonstrate the aperture's utility in real-time measurements and perform volumetric SAR imaging. The capabilities of a prototype are detailed and the future prospects of general dynamic metasurface apertures are discussed.

Capability of long distance 100  GHz FMCW using a single GDD lamp sensor.

PubMed

Levanon, Assaf; Rozban, Daniel; Aharon Akram, Avihai; Kopeika, Natan S; Yitzhaky, Yitzhak; Abramovich, Amir

2014-12-20

Millimeter wave (MMW)-based imaging systems are required for applications in medicine, homeland security, concealed weapon detection, and space technology. The lack of inexpensive room temperature imaging sensors makes it difficult to provide a suitable MMW system for many of the above applications. A 3D MMW imaging system based on chirp radar was studied previously using a scanning imaging system of a single detector. The radar system requires that the millimeter wave detector will be able to operate as a heterodyne detector. Since the source of radiation is a frequency modulated continuous wave (FMCW), the detected signal as a result of heterodyne detection gives the object's depth information according to value of difference frequency, in addition to the reflectance of the 2D image. New experiments show the capability of long distance FMCW detection by using a large scale Cassegrain projection system, described first (to our knowledge) in this paper. The system presents the capability to employ a long distance of at least 20 m with a low-cost plasma-based glow discharge detector (GDD) focal plane array (FPA). Each point on the object corresponds to a point in the image and includes the distance information. This will enable relatively inexpensive 3D MMW imaging.

In Vivo Deep Tissue Fluorescence and Magnetic Imaging Employing Hybrid Nanostructures.

PubMed

Ortgies, Dirk H; de la Cueva, Leonor; Del Rosal, Blanca; Sanz-Rodríguez, Francisco; Fernández, Nuria; Iglesias-de la Cruz, M Carmen; Salas, Gorka; Cabrera, David; Teran, Francisco J; Jaque, Daniel; Martín Rodríguez, Emma

2016-01-20

Breakthroughs in nanotechnology have made it possible to integrate different nanoparticles in one single hybrid nanostructure (HNS), constituting multifunctional nanosized sensors, carriers, and probes with great potential in the life sciences. In addition, such nanostructures could also offer therapeutic capabilities to achieve a wider variety of multifunctionalities. In this work, the encapsulation of both magnetic and infrared emitting nanoparticles into a polymeric matrix leads to a magnetic-fluorescent HNS with multimodal magnetic-fluorescent imaging abilities. The magnetic-fluorescent HNS are capable of simultaneous magnetic resonance imaging and deep tissue infrared fluorescence imaging, overcoming the tissue penetration limits of classical visible-light based optical imaging as reported here in living mice. Additionally, their applicability for magnetic heating in potential hyperthermia treatments is assessed.

FIZICS: fluorescent imaging zone identification system, a novel macro imaging system.

PubMed

Skwish, Stephen; Asensio, Francisco; King, Greg; Clarke, Glenn; Kath, Gary; Salvatore, Michael J; Dufresne, Claude

2004-12-01

Constantly improving biological assay development continues to drive technological requirements. Recently, a specification was defined for capturing white light and fluorescent images of agar plates ranging in size from the NUNC Omni tray (96-well footprint, 128 x 85 mm) to the NUNC Bio Assay Dish (245 x 245 mm). An evaluation of commercially available products failed to identify any system capable of fluorescent macroimaging with discrete wavelength selection. To address the lack of a commercially available system, a custom imaging system was designed and constructed. This system provides the same capabilities of many commercially available systems with the added ability to fluorescently image up to a 245 x 245 mm area using wavelengths in the visible light spectrum.

Advanced sensor-simulation capability

NASA Astrophysics Data System (ADS)

Cota, Stephen A.; Kalman, Linda S.; Keller, Robert A.

1990-09-01

This paper provides an overview of an advanced simulation capability currently in use for analyzing visible and infrared sensor systems. The software system, called VISTAS (VISIBLE/INFRARED SENSOR TRADES, ANALYSES, AND SIMULATIONS) combines classical image processing techniques with detailed sensor models to produce static and time dependent simulations of a variety of sensor systems including imaging, tracking, and point target detection systems. Systems modelled to date include space-based scanning line-array sensors as well as staring 2-dimensional array sensors which can be used for either imaging or point source detection.

Lens based adaptive optics scanning laser ophthalmoscope.

PubMed

Felberer, Franz; Kroisamer, Julia-Sophie; Hitzenberger, Christoph K; Pircher, Michael

2012-07-30

We present an alternative approach for an adaptive optics scanning laser ophthalmoscope (AO-SLO). In contrast to other commonly used AO-SLO instruments, the imaging optics consist of lenses. Images of the fovea region of 5 healthy volunteers are recorded. The system is capable to resolve human foveal cones in 3 out of 5 healthy volunteers. Additionally, we investigated the capability of the system to support larger scanning angles (up to 5°) on the retina. Finally, in order to demonstrate the performance of the instrument images of rod photoreceptors are presented.

Gamma-Ray imaging for nuclear security and safety: Towards 3-D gamma-ray vision

NASA Astrophysics Data System (ADS)

Vetter, Kai; Barnowksi, Ross; Haefner, Andrew; Joshi, Tenzing H. Y.; Pavlovsky, Ryan; Quiter, Brian J.

2018-01-01

The development of portable gamma-ray imaging instruments in combination with the recent advances in sensor and related computer vision technologies enable unprecedented capabilities in the detection, localization, and mapping of radiological and nuclear materials in complex environments relevant for nuclear security and safety. Though multi-modal imaging has been established in medicine and biomedical imaging for some time, the potential of multi-modal data fusion for radiological localization and mapping problems in complex indoor and outdoor environments remains to be explored in detail. In contrast to the well-defined settings in medical or biological imaging associated with small field-of-view and well-constrained extension of the radiation field, in many radiological search and mapping scenarios, the radiation fields are not constrained and objects and sources are not necessarily known prior to the measurement. The ability to fuse radiological with contextual or scene data in three dimensions, in analog to radiological and functional imaging with anatomical fusion in medicine, provides new capabilities enhancing image clarity, context, quantitative estimates, and visualization of the data products. We have developed new means to register and fuse gamma-ray imaging with contextual data from portable or moving platforms. These developments enhance detection and mapping capabilities as well as provide unprecedented visualization of complex radiation fields, moving us one step closer to the realization of gamma-ray vision in three dimensions.

Space Radar Image of Safsaf Oasis, Egypt

NASA Image and Video Library

1999-04-15

This three-frequency space radar image of south-central Egypt demonstrates the unique capability of imaging radar to penetrate thin sand cover in arid regions to reveal hidden details below the surface.

Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images

PubMed Central

Levenson, Richard M.; Krupinski, Elizabeth A.; Navarro, Victor M.; Wasserman, Edward A.

2015-01-01

Pathologists and radiologists spend years acquiring and refining their medically essential visual skills, so it is of considerable interest to understand how this process actually unfolds and what image features and properties are critical for accurate diagnostic performance. Key insights into human behavioral tasks can often be obtained by using appropriate animal models. We report here that pigeons (Columba livia)—which share many visual system properties with humans—can serve as promising surrogate observers of medical images, a capability not previously documented. The birds proved to have a remarkable ability to distinguish benign from malignant human breast histopathology after training with differential food reinforcement; even more importantly, the pigeons were able to generalize what they had learned when confronted with novel image sets. The birds’ histological accuracy, like that of humans, was modestly affected by the presence or absence of color as well as by degrees of image compression, but these impacts could be ameliorated with further training. Turning to radiology, the birds proved to be similarly capable of detecting cancer-relevant microcalcifications on mammogram images. However, when given a different (and for humans quite difficult) task—namely, classification of suspicious mammographic densities (masses)—the pigeons proved to be capable only of image memorization and were unable to successfully generalize when shown novel examples. The birds’ successes and difficulties suggest that pigeons are well-suited to help us better understand human medical image perception, and may also prove useful in performance assessment and development of medical imaging hardware, image processing, and image analysis tools. PMID:26581091

Pigeons (Columba livia) as Trainable Observers of Pathology and Radiology Breast Cancer Images.

PubMed

Levenson, Richard M; Krupinski, Elizabeth A; Navarro, Victor M; Wasserman, Edward A

2015-01-01

Pathologists and radiologists spend years acquiring and refining their medically essential visual skills, so it is of considerable interest to understand how this process actually unfolds and what image features and properties are critical for accurate diagnostic performance. Key insights into human behavioral tasks can often be obtained by using appropriate animal models. We report here that pigeons (Columba livia)-which share many visual system properties with humans-can serve as promising surrogate observers of medical images, a capability not previously documented. The birds proved to have a remarkable ability to distinguish benign from malignant human breast histopathology after training with differential food reinforcement; even more importantly, the pigeons were able to generalize what they had learned when confronted with novel image sets. The birds' histological accuracy, like that of humans, was modestly affected by the presence or absence of color as well as by degrees of image compression, but these impacts could be ameliorated with further training. Turning to radiology, the birds proved to be similarly capable of detecting cancer-relevant microcalcifications on mammogram images. However, when given a different (and for humans quite difficult) task-namely, classification of suspicious mammographic densities (masses)-the pigeons proved to be capable only of image memorization and were unable to successfully generalize when shown novel examples. The birds' successes and difficulties suggest that pigeons are well-suited to help us better understand human medical image perception, and may also prove useful in performance assessment and development of medical imaging hardware, image processing, and image analysis tools.

An earth imaging camera simulation using wide-scale construction of reflectance surfaces

NASA Astrophysics Data System (ADS)

Murthy, Kiran; Chau, Alexandra H.; Amin, Minesh B.; Robinson, M. Dirk

2013-10-01

Developing and testing advanced ground-based image processing systems for earth-observing remote sensing applications presents a unique challenge that requires advanced imagery simulation capabilities. This paper presents an earth-imaging multispectral framing camera simulation system called PayloadSim (PaySim) capable of generating terabytes of photorealistic simulated imagery. PaySim leverages previous work in 3-D scene-based image simulation, adding a novel method for automatically and efficiently constructing 3-D reflectance scenes by draping tiled orthorectified imagery over a geo-registered Digital Elevation Map (DEM). PaySim's modeling chain is presented in detail, with emphasis given to the techniques used to achieve computational efficiency. These techniques as well as cluster deployment of the simulator have enabled tuning and robust testing of image processing algorithms, and production of realistic sample data for customer-driven image product development. Examples of simulated imagery of Skybox's first imaging satellite are shown.

Label-free in vivo optical micro-angiography imaging of cerebral capillary blood flow within meninges and cortex in mice with the skull left intact

NASA Astrophysics Data System (ADS)

Jia, Yali; Wang, Ruikang K.

2011-03-01

Abnormal microcirculation within meninges is common in many neurological diseases. There is a need for an imaging method that is capable of visualizing functional meningeal microcirculations alone, preferably decoupled from the cortical blood flow. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing 3D images of dynamic blood perfusion within micro-circulatory tissue beds at an imaging depth up to ~2 mm, with an unprecedented imaging sensitivity to the blood flow at ~4 μm/s. In this study, we demonstrate the utility of ultra-high sensitive OMAG in imaging the detailed blood flow distributions, at a capillary level resolution, within meninges and cortex in mice with the cranium left intact. The results indicate that OMAG can be a valuable tool for the study of meningeal circulations.

Ultrahigh-speed X-ray imaging of hypervelocity projectiles

NASA Astrophysics Data System (ADS)

Miller, Stuart; Singh, Bipin; Cool, Steven; Entine, Gerald; Campbell, Larry; Bishel, Ron; Rushing, Rick; Nagarkar, Vivek V.

2011-08-01

High-speed X-ray imaging is an extremely important modality for healthcare, industrial, military and research applications such as medical computed tomography, non-destructive testing, imaging in-flight projectiles, characterizing exploding ordnance, and analyzing ballistic impacts. We report on the development of a modular, ultrahigh-speed, high-resolution digital X-ray imaging system with large active imaging area and microsecond time resolution, capable of acquiring at a rate of up to 150,000 frames per second. The system is based on a high-resolution, high-efficiency, and fast-decay scintillator screen optically coupled to an ultra-fast image-intensified CCD camera designed for ballistic impact studies and hypervelocity projectile imaging. A specially designed multi-anode, high-fluence X-ray source with 50 ns pulse duration provides a sequence of blur-free images of hypervelocity projectiles traveling at speeds exceeding 8 km/s (18,000 miles/h). This paper will discuss the design, performance, and high frame rate imaging capability of the system.

InSAR imaging of volcanic deformation over cloud-prone areas - Aleutian islands

USGS Publications Warehouse

Lu, Zhong

2007-01-01

Interferometric synthetic aperture radar (INSAR) is capable of measuring ground-surface deformation with centimeter-tosubcentimeter precision and spatial resolution of tens-of meters over a relatively large region. With its global coverage and all-weather imaging capability, INSAR is an important technique for measuring ground-surface deformation of volcanoes over cloud-prone and rainy regions such as the Aleutian Islands, where only less than 5 percent of optical imagery is usable due to inclement weather conditions. The spatial distribution of surface deformation data, derived from INSAR images, enables the construction of detailed mechanical models to enhance the study of magmatic processes. This paper reviews the basics of INSAR for volcanic deformation mapping and the INSAR studies of ten Aleutian volcanoes associated with both eruptive and noneruptive activity. These studies demonstrate that all-weather INSAR imaging can improve our understanding of how the Aleutian volcanoes work and enhance our capability to predict future eruptions and associated hazards.

Hyperspectral Cubesat Constellation for Rapid Natural Hazard Response

NASA Technical Reports Server (NTRS)

Mandl, Daniel; Huemmrich, Karl; Crum, Gary; Ly, Vuong; Handy, Matthew; Ong, Lawrence

2015-01-01

Earth Observing 1 (E0-1) satellite has an imaging spectrometer (hyperspectral) instrument called Hyperion. The satellite is able to image any spot on Earth in the nadir looking direction every 16 days. With slewing of the satellite and allowing for up to a 23 degree view angle, any spot on the Earth can be imaged approximately every 2 to 3 days. EO-1 has been used to track many natural hazards such as wildfires, volcanoes and floods. An enhanced capability that is sought is the ability to image natural hazards in a daily time series for space based imaging spectrometers. The Hyperion can not provide this capability on EO-1 with the present polar orbit. However, a constellation of cubesats, each with the same imaging spectrometer, positioned strategically in the same orbit, can be used to provide daily coverage, cost-effectively.

Pulse compression favourable aperiodic infrared imaging approach for non-destructive testing and evaluation of bio-materials

NASA Astrophysics Data System (ADS)

Mulaveesala, Ravibabu; Dua, Geetika; Arora, Vanita; Siddiqui, Juned A.; Muniyappa, Amarnath

2017-05-01

In recent years, aperiodic, transient pulse compression favourable infrared imaging methodologies demonstrated as reliable, quantitative, remote characterization and evaluation techniques for testing and evaluation of various biomaterials. This present work demonstrates a pulse compression favourable aperiodic thermal wave imaging technique, frequency modulated thermal wave imaging technique for bone diagnostics, especially by considering the bone with tissue, skin and muscle over layers. In order to find the capabilities of the proposed frequency modulated thermal wave imaging technique to detect the density variations in a multi layered skin-fat-muscle-bone structure, finite element modeling and simulation studies have been carried out. Further, frequency and time domain post processing approaches have been adopted on the temporal temperature data in order to improve the detection capabilities of frequency modulated thermal wave imaging.

High-contrast imaging in the cloud with klipReduce and Findr

NASA Astrophysics Data System (ADS)

Haug-Baltzell, Asher; Males, Jared R.; Morzinski, Katie M.; Wu, Ya-Lin; Merchant, Nirav; Lyons, Eric; Close, Laird M.

2016-08-01

Astronomical data sets are growing ever larger, and the area of high contrast imaging of exoplanets is no exception. With the advent of fast, low-noise detectors operating at 10 to 1000 Hz, huge numbers of images can be taken during a single hours-long observation. High frame rates offer several advantages, such as improved registration, frame selection, and improved speckle calibration. However, advanced image processing algorithms are computationally challenging to apply. Here we describe a parallelized, cloud-based data reduction system developed for the Magellan Adaptive Optics VisAO camera, which is capable of rapidly exploring tens of thousands of parameter sets affecting the Karhunen-Loève image processing (KLIP) algorithm to produce high-quality direct images of exoplanets. We demonstrate these capabilities with a visible wavelength high contrast data set of a hydrogen-accreting brown dwarf companion.

Laparoscopic optical coherence tomographic imaging of human ovarian cancer

NASA Astrophysics Data System (ADS)

Hariri, Lida P.; Bonnema, Garret T.; Schmidt, Kathy; Hatch, Kenneth; Brewer, Molly; Barton, Jennifer K.

2008-02-01

Ovarian cancer is the fourth leading cause of cancer-related death among women in the United States. If diagnosed at an early stage, the 5-year survival rate is 94%, but drops to 68% for regional disease and 29% for distant metastasis; only 19% of all cases are diagnosed at the early, localized stage. Optical coherence tomography is a recently emerging non-destructive imaging technology, achieving high axial resolutions (10-20 microns) at imaging depths up to 2 mm. Previously, we studied OCT imaging in normal and diseased human ovary ex vivo to determine the features OCT is capable of resolving. Changes in collagen were suggested with several of the images that correlated with changes in collagen seen in malignancy. Areas of necrosis and blood vessels were also visualized using OCT, indicative of an underlying tissue abnormality. We recently developed a custom side-firing laparoscopic OCT (LOCT) probe fabricated specifically for in vivo laparoscopic imaging. The LOCT probe consists of a 38 mm diameter handpiece terminated in an 280 mm long, 4.6 mm diameter tip for insertion into the laparoscopic trocar and is capable of obtaining up to 9.5 mm image lengths at 10 micron axial resolution. In this study, we utilize the LOCT probe to image one or both ovaries of 20 patients undergoing laparotomy or transabdominal endoscopy and oophorectomy to determine if OCT is capable of identifying and/or differentiating normal and neoplastic ovary. To date, we have laparoscopically imaged the ovaries of ten patients successfully with no known complications.

ECAT: A New Computerized Tomographic Imaging System for Position-Emitting Radiopharmaceuticals

DOE R&D Accomplishments Database

Phelps, M. E.; Hoffman, E. J.; Huang, S. C.; Kuhl, D. E.

1977-01-01

The ECAT was designed and developed as a complete computerized positron radionuclide imaging system capable of providing high contrast, high resolution, quantitative images in 2 dimensional and tomographic formats. Flexibility, in its various image mode options, allows it to be used for a wide variety of imaging problems.

Satellite-based Tropical Cyclone Monitoring Capabilities

NASA Astrophysics Data System (ADS)

Hawkins, J.; Richardson, K.; Surratt, M.; Yang, S.; Lee, T. F.; Sampson, C. R.; Solbrig, J.; Kuciauskas, A. P.; Miller, S. D.; Kent, J.

2012-12-01

Satellite remote sensing capabilities to monitor tropical cyclone (TC) location, structure, and intensity have evolved by utilizing a combination of operational and research and development (R&D) sensors. The microwave imagers from the operational Defense Meteorological Satellite Program [Special Sensor Microwave/Imager (SSM/I) and the Special Sensor Microwave Imager Sounder (SSMIS)] form the "base" for structure observations due to their ability to view through upper-level clouds, modest size swaths and ability to capture most storm structure features. The NASA TRMM microwave imager and precipitation radar continue their 15+ yearlong missions in serving the TC warning and research communities. The cessation of NASA's QuikSCAT satellite after more than a decade of service is sorely missed, but India's OceanSat-2 scatterometer is now providing crucial ocean surface wind vectors in addition to the Navy's WindSat ocean surface wind vector retrievals. Another Advanced Scatterometer (ASCAT) onboard EUMETSAT's MetOp-2 satellite is slated for launch soon. Passive microwave imagery has received a much needed boost with the launch of the French/Indian Megha Tropiques imager in September 2011, basically greatly supplementing the very successful NASA TRMM pathfinder with a larger swath and more frequent temporal sampling. While initial data issues have delayed data utilization, current news indicates this data will be available in 2013. Future NASA Global Precipitation Mission (GPM) sensors starting in 2014 will provide enhanced capabilities. Also, the inclusion of the new microwave sounder data from the NPP ATMS (Oct 2011) will assist in mapping TC convective structures. The National Polar orbiting Partnership (NPP) program's VIIRS sensor includes a day night band (DNB) with the capability to view TC cloud structure at night when sufficient lunar illumination exits. Examples highlighting this new capability will be discussed in concert with additional data fusion efforts.

ACS Data Handbook v.6.0

NASA Astrophysics Data System (ADS)

Gonzaga, S.; et al.

2011-03-01

ACS was designed to provide a deep, wide-field survey capability from the visible to near-IR using the Wide Field Camera (WFC), high resolution imaging from the near-UV to near-IR with the now-defunct High Resolution Camera (HRC), and solar-blind far-UV imaging using the Solar Blind Camera (SBC). The discovery efficiency of ACS's Wide Field Channel (i.e., the product of WFC's field of view and throughput) is 10 times greater than that of WFPC2. The failure of ACS's CCD electronics in January 2007 brought a temporary halt to CCD imaging until Servicing Mission 4 in May 2009, when WFC functionality was restored. Unfortunately, the high-resolution optical imaging capability of HRC was not recovered.

Online Multitasking Line-Scan Imaging Techniques for Simultaneous Safety and Quality Evaluation of Apples

NASA Astrophysics Data System (ADS)

Kim, Moon Sung; Lee, Kangjin; Chao, Kaunglin; Lefcourt, Alan; Cho, Byung-Kwan; Jun, Won

We developed a push-broom, line-scan imaging system capable of simultaneous measurements of reflectance and fluorescence. The system allows multitasking inspections for quality and safety attributes of apples due to its dynamic capabilities in simultaneously capturing fluorescence and reflectance, and selectivity in multispectral bands. A multitasking image-based inspection system for online applications has been suggested in that a single imaging device that could perform a multitude of both safety and quality inspection needs. The presented multitask inspection approach in online applications may provide an economically viable means for a number of food processing industries being able to adapt to operate and meet the dynamic and specific inspection and sorting needs.

Hybrid cryptosystem for image file using elgamal and double playfair cipher algorithm

NASA Astrophysics Data System (ADS)

Hardi, S. M.; Tarigan, J. T.; Safrina, N.

2018-03-01

In this paper, we present an implementation of an image file encryption using hybrid cryptography. We chose ElGamal algorithm to perform asymmetric encryption and Double Playfair for the symmetric encryption. Our objective is to show that these algorithms are capable to encrypt an image file with an acceptable running time and encrypted file size while maintaining the level of security. The application was built using C# programming language and ran as a stand alone desktop application under Windows Operating System. Our test shows that the system is capable to encrypt an image with a resolution of 500×500 to a size of 976 kilobytes with an acceptable running time.

Enhanced visualization of the bile duct via parallel white light and indocyanine green fluorescence laparoscopic imaging

NASA Astrophysics Data System (ADS)

Demos, Stavros G.; Urayama, Shiro

2014-03-01

Despite best efforts, bile duct injury during laparoscopic cholecystectomy is a major potential complication. Precise detection method of extrahepatic bile duct during laparoscopic procedures would minimize the risk of injury. Towards this goal, we have developed a compact imaging instrumentation designed to enable simultaneous acquisition of conventional white color and NIR fluorescence endoscopic/laparoscopic imaging using ICG as contrast agent. The capabilities of this system, which offers optimized sensitivity and functionality, are demonstrated for the detection of the bile duct in an animal model. This design could also provide a low-cost real-time surgical navigation capability to enhance the efficacy of a variety of other image-guided minimally invasive procedures.

Protein-Based Multifunctional Nanocarriers for Imaging, Photothermal Therapy, and Anticancer Drug Delivery.

PubMed

Pan, Uday Narayan; Khandelia, Rumi; Sanpui, Pallab; Das, Subhojit; Paul, Anumita; Chattopadhyay, Arun

2017-06-14

We report a simple approach for fabricating plasmonic and magneto-luminescent multifunctional nanocarriers (MFNCs) by assembling gold nanorods, iron oxide nanoparticles, and gold nanoclusters within BSA nanoparticles. The MFNCs showed self-tracking capability through single- and two-photon imaging, and the potential for magnetic targeting in vitro. Appreciable T 2 -relaxivity exhibited by the MFNCs indicated favorable conditions for magnetic resonance imaging. In addition to successful plasmonic-photothermal therapy of cancer cells (HeLa) in vitro, the MFNCs demonstrated efficient loading and delivery of doxorubicin to HeLa cells leading to significant cell death. The present MFNCs with their multimodal imaging and therapeutic capabilities could be eminent candidates for cancer theranostics.

Autonomous GN and C for Spacecraft Exploration of Comets and Asteroids

NASA Technical Reports Server (NTRS)

Carson, John M.; Mastrodemos, Nickolaos; Myers, David M.; Acikmese, Behcet; Blackmore, James C.; Moussalis, Dhemetrio; Riedel, Joseph E.; Nolet, Simon; Chang, Johnny T.; Mandic, Milan;

Super Resolution Imaging of the Bottomside Ionosphere with the LWA

NASA Astrophysics Data System (ADS)

Obenberger, K.; Parris, R. T.; Taylor, G. B.; Dowell, J.; Malins, J. B.; Pedersen, T.

2017-12-01

Standard ionospheric sounding instruments typically only utilize a handful HF antennas to receive their transmitted signal, and therefore are limited in their ability to image reflections from the bottomside ionosphere. This limitation is primarily due to the low signal to noise ratio of only a few receiving elements. However, recent advancements in digital processing have ushered in a new era of many-element radio telescopes, capable of sub degree all-sky imaging in the HF band. The Long Wavelength Array station at Sevilleta National Wildlife Refuge, New Mexico (LWA-SV), which was specifically designed with improved HF performance for imaging bottomside propagation, began observations this year. I will discuss the new capabilities and imaging techniques of LWA-SV, and show some preliminary measurements of small scale ionospheric structure.

Associative memory model for searching an image database by image snippet

NASA Astrophysics Data System (ADS)

Khan, Javed I.; Yun, David Y.

1994-09-01

This paper presents an associative memory called an multidimensional holographic associative computing (MHAC), which can be potentially used to perform feature based image database query using image snippet. MHAC has the unique capability to selectively focus on specific segments of a query frame during associative retrieval. As a result, this model can perform search on the basis of featural significance described by a subset of the snippet pixels. This capability is critical for visual query in image database because quite often the cognitive index features in the snippet are statistically weak. Unlike, the conventional artificial associative memories, MHAC uses a two level representation and incorporates additional meta-knowledge about the reliability status of segments of information it receives and forwards. In this paper we present the analysis of focus characteristics of MHAC.

An Open Source Agenda for Research Linking Text and Image Content Features.

ERIC Educational Resources Information Center

Goodrum, Abby A.; Rorvig, Mark E.; Jeong, Ki-Tai; Suresh, Chitturi

2001-01-01

Proposes methods to utilize image primitives to support term assignment for image classification. Proposes to release code for image analysis in a common tool set for other researchers to use. Of particular focus is the expansion of work by researchers in image indexing to include image content-based feature extraction capabilities in their work.…

Advanced X-ray Astrophysics Facility (AXAF): An overview

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; ODell, S. L.; Elsner, R. F.; VanSpeybroeck, L. P.

1995-01-01

The Advanced X-ray Astrophysics Facility (AXAF) is the x-ray component of NASA's Great Observatories. To be launched in late 1998, AXAF will provide unprecedented capabilities for high-resolution imaging, spectrometric imaging, and high-resolution disperse spectroscopy, over the x-ray band from about 0.1 keV to 10 keV. With these capabilities, AXAF observations will address many of the outstanding questions in astronomy, astrophysics, and cosmology.

Devices useful for vacuum ultraviolet beam characterization including a movable stage with a transmission grating and image detector

DOEpatents

Gessner, Oliver; Kornilov, Oleg A; Wilcox, Russell B

2013-10-29

The invention provides for a device comprising an apparatus comprising (a) a transmission grating capable of diffracting a photon beam into a diffracted photon output, and (b) an image detector capable of detecting the diffracted photon output. The device is useful for measuring the spatial profile and diffraction pattern of a photon beam, such as a vacuum ultraviolet (VUV) beam.

Perspective: Advanced particle imaging

PubMed Central

Chandler, David W.

2017-01-01

Since the first ion imaging experiment [D. W. Chandler and P. L. Houston, J. Chem. Phys. 87, 1445–1447 (1987)], demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variance and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable “complete” experiments—the holy grail of molecular dynamics—where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control. PMID:28688442

Towards establishing compact imaging spectrometer standards

USGS Publications Warehouse

Slonecker, E. Terrence; Allen, David W.; Resmini, Ronald G.

2016-01-01

Remote sensing science is currently undergoing a tremendous expansion in the area of hyperspectral imaging (HSI) technology. Spurred largely by the explosive growth of Unmanned Aerial Vehicles (UAV), sometimes called Unmanned Aircraft Systems (UAS), or drones, HSI capabilities that once required access to one of only a handful of very specialized and expensive sensor systems are now miniaturized and widely available commercially. Small compact imaging spectrometers (CIS) now on the market offer a number of hyperspectral imaging capabilities in terms of spectral range and sampling. The potential uses of HSI/CIS on UAVs/UASs seem limitless. However, the rapid expansion of unmanned aircraft and small hyperspectral sensor capabilities has created a number of questions related to technological, legal, and operational capabilities. Lightweight sensor systems suitable for UAV platforms are being advertised in the trade literature at an ever-expanding rate with no standardization of system performance specifications or terms of reference. To address this issue, both the U.S. Geological Survey and the National Institute of Standards and Technology are eveloping draft standards to meet these issues. This paper presents the outline of a combined USGS/NIST cooperative strategy to develop and test a characterization methodology to meet the needs of a new and expanding UAV/CIS/HSI user community.

Single-frequency 3D synthetic aperture imaging with dynamic metasurface antennas.

PubMed

Boyarsky, Michael; Sleasman, Timothy; Pulido-Mancera, Laura; Diebold, Aaron V; Imani, Mohammadreza F; Smith, David R

2018-05-20

Through aperture synthesis, an electrically small antenna can be used to form a high-resolution imaging system capable of reconstructing three-dimensional (3D) scenes. However, the large spectral bandwidth typically required in synthetic aperture radar systems to resolve objects in range often requires costly and complex RF components. We present here an alternative approach based on a hybrid imaging system that combines a dynamically reconfigurable aperture with synthetic aperture techniques, demonstrating the capability to resolve objects in three dimensions (3D), with measurements taken at a single frequency. At the core of our imaging system are two metasurface apertures, both of which consist of a linear array of metamaterial irises that couple to a common waveguide feed. Each metamaterial iris has integrated within it a diode that can be biased so as to switch the element on (radiating) or off (non-radiating), such that the metasurface antenna can produce distinct radiation profiles corresponding to different on/off patterns of the metamaterial element array. The electrically large size of the metasurface apertures enables resolution in range and one cross-range dimension, while aperture synthesis provides resolution in the other cross-range dimension. The demonstrated imaging capabilities of this system represent a step forward in the development of low-cost, high-performance 3D microwave imaging systems.

Noninvasive Reactor Imaging Using Cosmic-Ray Muons

NASA Astrophysics Data System (ADS)

Miyadera, H.; Fujita, K.; Karino, Y.; Kume, N.; Nakayama, K.; Sano, Y.; Sugita, T.; Yoshioka, K.; Morris, C. L.; Bacon, J. D.; Borozdin, K. N.; Perry, J. O.; Mizokami, S.; Otsuka, Y.; Yamada, D.

2015-10-01

Cosmic-ray-muon imaging is proposed to assess the damages to the Fukushima Daiichi reactors. Simulation studies showed capability of muon imaging to reveal the core conditions.The muon-imaging technique was demonstrated at Toshiba Nuclear Critical Assembly, where the uranium-dioxide fuel assembly was imaged with 3-cm spatial resolution after 1 month of measurement.

Study of Tissue Phantoms, Tissues, and Contrast Agent with the Biophotoacoustic Radar and Comparison to Ultrasound Imaging for Deep Subsurface Imaging

NASA Astrophysics Data System (ADS)

Alwi, R.; Telenkov, S.; Mandelis, A.; Gu, F.

2012-11-01

In this study, the imaging capability of our wide-spectrum frequency-domain photoacoustic (FD-PA) imaging alias "photoacoustic radar" methodology for imaging of soft tissues is explored. A practical application of the mathematical correlation processing method with relatively long (1 ms) frequency-modulated optical excitation is demonstrated for reconstruction of the spatial location of the PA sources. Image comparison with ultrasound (US) modality was investigated to see the complementarity between the two techniques. The obtained results with a phased array probe on tissue phantoms and their comparison to US images demonstrated that the FD-PA technique has strong potential for deep subsurface imaging with excellent contrast and high signal-to-noise ratio. FD-PA images of blood vessels in a human wrist and an in vivo subcutaneous tumor in a rat model are presented. As in other imaging modalities, the employment of contrast agents is desirable to improve the capability of medical diagnostics. Therefore, this study also evaluated and characterized the use of Food and Drug Administration (FDA)-approved superparamagnetic iron oxide nanoparticles (SPION) as PA contrast agents.

Bayesian superresolution

NASA Astrophysics Data System (ADS)

Isakson, Steve Wesley

2001-12-01

Well-known principles of physics explain why resolution restrictions occur in images produced by optical diffraction-limited systems. The limitations involved are present in all diffraction-limited imaging systems, including acoustical and microwave. In most circumstances, however, prior knowledge about the object and the imaging system can lead to resolution improvements. In this dissertation I outline a method to incorporate prior information into the process of reconstructing images to superresolve the object beyond the above limitations. This dissertation research develops the details of this methodology. The approach can provide the most-probable global solution employing a finite number of steps in both far-field and near-field images. In addition, in order to overcome the effects of noise present in any imaging system, this technique provides a weighted image that quantifies the likelihood of various imaging solutions. By utilizing Bayesian probability, the procedure is capable of incorporating prior information about both the object and the noise to overcome the resolution limitation present in many imaging systems. Finally I will present an imaging system capable of detecting the evanescent waves missing from far-field systems, thus improving the resolution further.

Synthetic aperture ultrasound imaging with a ring transducer array: preliminary ex vivo results.

PubMed

Qu, Xiaolei; Azuma, Takashi; Yogi, Takeshi; Azuma, Shiho; Takeuchi, Hideki; Tamano, Satoshi; Takagi, Shu

2016-10-01

The conventional medical ultrasound imaging has a low lateral spatial resolution, and the image quality depends on the depth of the imaging location. To overcome these problems, this study presents a synthetic aperture (SA) ultrasound imaging method using a ring transducer array. An experimental ring transducer array imaging system was constructed. The array was composed of 2048 transducer elements, and had a diameter of 200 mm and an inter-element pitch of 0.325 mm. The imaging object was placed in the center of the ring transducer array, which was immersed in water. SA ultrasound imaging was then employed to scan the object and reconstruct the reflection image. Both wire phantom and ex vivo experiments were conducted. The proposed method was found to be capable of producing isotropic high-resolution images of the wire phantom. In addition, preliminary ex vivo experiments using porcine organs demonstrated the ability of the method to reconstruct high-quality images without any depth dependence. The proposed ring transducer array and SA ultrasound imaging method were shown to be capable of producing isotropic high-resolution images whose quality was independent of depth.

An ultra-wideband microwave tomography system: preliminary results.

PubMed

Gilmore, Colin; Mojabi, Puyan; Zakaria, Amer; Ostadrahimi, Majid; Kaye, Cam; Noghanian, Sima; Shafai, Lotfollah; Pistorius, Stephen; LoVetri, Joe

2009-01-01

We describe a 2D wide-band multi-frequency microwave imaging system intended for biomedical imaging. The system is capable of collecting data from 2-10 GHz, with 24 antenna elements connected to a vector network analyzer via a 2 x 24 port matrix switch. Through the use of two different nonlinear reconstruction schemes: the Multiplicative-Regularized Contrast Source Inversion method and an enhanced version of the Distorted Born Iterative Method, we show preliminary imaging results from dielectric phantoms where data were collected from 3-6 GHz. The early inversion results show that the system is capable of quantitatively reconstructing dielectric objects.

Use of computed tomography to define a sacral safe corridor for placement of 2.7 mm cortical screws in feline sacroiliac luxation.

PubMed

Philp, Helen; Durand, Alexane; De Vicente, Felipe

2018-06-01

Objectives This study aimed to define a safe corridor for 2.7 mm cortical sacroiliac screw insertion in the dorsal plane (craniocaudal direction) using radiography and CT, and in the transverse plane (dorsoventral direction) using CT in feline cadavers. A further aim was to compare the values obtained by CT with those previously reported by radiography in the transverse plane. Methods Thirteen pelvises were retrieved from feline cadavers and dissected to expose one of the articular surfaces of the sacrum. A 2.7 mm screw was placed in the sacrum to a depth of approximately 1 cm in each exposed articular surface. Dorsoventral radiography and CT scanning of each specimen were performed. Multiplanar reconstructions were performed to allow CT evaluation in both the dorsal and transverse planes. Calculations were made to find the maximum, minimum and optimum angles for screw placement in craniocaudal (radiography and CT) and dorsoventral (CT) directions when using a 2.7 mm cortical screw. Results Radiographic measurement showed a mean optimum craniocaudal angle of 106° (range 97-112°). The mean minimum angle was 95° (range 87-107°), whereas the mean maximum angle was 117° (108-124°). Measurement of the dorsal CT scan images showed a mean optimum craniocaudal angle of 101° (range 94-110°). The mean minimum angle was 90° (range 83-99°), whereas the mean maximum angle was 113° (104-125°). The transverse CT scan images showed a mean dorsoventral minimum angle of 103° (range 95-113°), mean maximum angle of 115° (104-125°) and mean optimum dorsoventral angle of 111° (102-119°). Conclusions and relevance An optimum craniocaudal angle of 101° is recommended for 2.7 mm cortical screw placement in the feline sacral body, with a safety margin between 99° and 104°. No single angle can be recommended in the dorsoventral direction and therefore preoperative measuring on individual cats using CT images is recommended to establish the ideal individual angle in the transverse plane.

Multi-modality endoscopic imaging for the detection of colorectal cancer

NASA Astrophysics Data System (ADS)

Wall, Richard Andrew

Optical coherence tomography (OCT) is an imaging method that is considered the optical analog to ultrasound, using the technique of optical interferometry to construct two-dimensional depth-resolved images of tissue microstructure. With a resolution on the order of 10 um and a penetration depth of 1-2 mm in highly scattering tissue, fiber optics-coupled OCT is an ideal modality for the inspection of the mouse colon with its miniaturization capabilities. In the present study, the complementary modalities laser-induced fluorescence (LIF), which offers information on the biochemical makeup of the tissue, and surface magnifying chromoendoscopy, which offers high contrast surface visualization, are combined with OCT in endoscopic imaging systems for the greater specificity and sensitivity in the differentiation between normal and neoplastic tissue, and for the visualization of biomarkers which are indicative of early events in colorectal carcinogenesis. Oblique incidence reflectometry (OIR) also offers advantages, allowing the calculation of bulk tissue optical properties for use as a diagnostic tool. The study was broken up into three specific sections. First, a dual-modality OCTLIF imaging system was designed, capable of focusing light over 325-1300 nm using a reflective distal optics design. A dual-modality fluorescence-based SMC-OCT system was then designed and constructed, capable of resolving the stained mucosal crypt structure of the in vivo mouse colon. The SMC-OCT instrument's OIR capabilities were then modeled, as a modified version of the probe was used measure tissue scattering and absorption coefficients.

Time stamping of single optical photons with 10 ns resolution

NASA Astrophysics Data System (ADS)

Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin; Hodges, Diedra R.; Nguyen, Jayke; Nomerotski, Andrei

2017-05-01

High spatial and temporal resolution are key features for many modern applications, e.g. mass spectrometry, probing the structure of materials via neutron scattering, studying molecular structure, etc.1-5 Fast imaging also provides the capability of coincidence detection, and the further addition of sensitivity to single optical photons with the capability of timestamping them further broadens the field of potential applications. Photon counting is already widely used in X-ray imaging,6 where the high energy of the photons makes their detection easier. TimepixCam is a novel optical imager,7 which achieves high spatial resolution using an array of 256×256 55 μm × 55μm pixels which have individually controlled functionality. It is based on a thin-entrance-window silicon sensor, bump-bonded to a Timepix ASIC.8 TimepixCam provides high quantum efficiency in the optical wavelength range (400-1000 nm). We perform the timestamping of single photons with a time resolution of 20 ns, by coupling TimepixCam to a fast image-intensifier with a P47 phosphor screen. The fast emission time of the P479 allows us to preserve good time resolution while maintaining the capability to focus the optical output of the intensifier onto the 256×256 pixel Timepix sensor area. We demonstrate the capability of the (TimepixCam + image intensifier) setup to provide high-resolution single-photon timestamping, with an effective frame rate of 50 MHz.

Smart image sensors: an emerging key technology for advanced optical measurement and microsystems

NASA Astrophysics Data System (ADS)

Seitz, Peter

1996-08-01

Optical microsystems typically include photosensitive devices, analog preprocessing circuitry and digital signal processing electronics. The advances in semiconductor technology have made it possible today to integrate all photosensitive and electronical devices on one 'smart image sensor' or photo-ASIC (application-specific integrated circuits containing photosensitive elements). It is even possible to provide each 'smart pixel' with additional photoelectronic functionality, without compromising the fill factor substantially. This technological capability is the basis for advanced cameras and optical microsystems showing novel on-chip functionality: Single-chip cameras with on- chip analog-to-digital converters for less than $10 are advertised; image sensors have been developed including novel functionality such as real-time selectable pixel size and shape, the capability of performing arbitrary convolutions simultaneously with the exposure, as well as variable, programmable offset and sensitivity of the pixels leading to image sensors with a dynamic range exceeding 150 dB. Smart image sensors have been demonstrated offering synchronous detection and demodulation capabilities in each pixel (lock-in CCD), and conventional image sensors are combined with an on-chip digital processor for complete, single-chip image acquisition and processing systems. Technological problems of the monolithic integration of smart image sensors include offset non-uniformities, temperature variations of electronic properties, imperfect matching of circuit parameters, etc. These problems can often be overcome either by designing additional compensation circuitry or by providing digital correction routines. Where necessary for technological or economic reasons, smart image sensors can also be combined with or realized as hybrids, making use of commercially available electronic components. It is concluded that the possibilities offered by custom smart image sensors will influence the design and the performance of future electronic imaging systems in many disciplines, reaching from optical metrology to machine vision on the factory floor and in robotics applications.

High-Energy Neutron Imaging Development at LLNL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, J M; Rusnak, B; Shen, S

2005-02-16

We are proceeding with the development of a high-energy (10 MeV) neutron imaging system for use as an inspection tool in nuclear stockpile stewardship applications. Our goal is to develop and deploy an imaging system capable of detecting cubic-mm-scale voids, cracks or other significant structural defects in heavily-shielded low-Z materials within nuclear device components. The final production-line system will be relatively compact (suitable for use in existing facilities within the DOE complex) and capable of acquiring both radiographic and tomographic (CT) images. In this report, we will review our recent programmatic accomplishments, focusing primarily on progress made in FY04. Themore » design status of the high-intensity, accelerator-driven neutron source and large-format imaging detector associated with the system will be discussed and results from a recent high-energy neutron imaging experiment conducted at the Ohio University Accelerator Laboratory (OUAL) will also be presented.« less

Bitcoin, Blockchains and Efficient Distributed Spacecraft Mission Control

NASA Technical Reports Server (NTRS)

Mandl, Dan

2017-01-01

Earth Observing 1 (E0-1) satellite has an imaging spectrometer (hyperspectral) instrument called Hyperion. The satellite is able to image any spot on Earth in the nadir looking direction every 16 days. With slewing of the satellite and allowing for up to a 23 degree view angle, any spot on the Earth can be imaged approximately every 2 to 3 days. EO-1 has been used to track many natural hazards such as wildfires, volcanoes and floods. An enhanced capability that is sought is the ability to image natural hazards in a daily time series for space based imaging spectrometers. The Hyperion can not provide this capability on EO-1 with the present polar orbit. However, a constellation of cubesats each powered with Intelligent Payload Modules, and each with copies of a commercial imaging spectrometer, positioned strategically in the same orbit, can be used to provide daily coverage, cost-effectively.

An efficient approach to integrated MeV ion imaging.

PubMed

Nikbakht, T; Kakuee, O; Solé, V A; Vosuoghi, Y; Lamehi-Rachti, M

2018-03-01

An ionoluminescence (IL) spectral imaging system, besides the common MeV ion imaging facilities such as µ-PIXE and µ-RBS, is implemented at the Van de Graaff laboratory of Tehran. A versatile processing software is required to handle the large amount of data concurrently collected in µ-IL and common MeV ion imaging measurements through the respective methodologies. The open-source freeware PyMca, with image processing and multivariate analysis capabilities, is employed to simultaneously process common MeV ion imaging and µ-IL data. Herein, the program was adapted to support the OM_DAQ listmode data format. The appropriate performance of the µ-IL data acquisition system is confirmed through a case study. Moreover, the capabilities of the software for simultaneous analysis of µ-PIXE and µ-RBS experimental data are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

Biomolecular Imaging with Coherent Nonlinear Vibrational Microscopy

PubMed Central

Chung, Chao-Yu; Boik, John; Potma, Eric O.

2014-01-01

Optical imaging with spectroscopic vibrational contrast is a label-free solution for visualizing, identifying, and quantifying a wide range of biomolecular compounds in biological materials. Both linear and nonlinear vibrational microscopy techniques derive their imaging contrast from infrared active or Raman allowed molecular transitions, which provide a rich palette for interrogating chemical and structural details of the sample. Yet nonlinear optical methods, which include both second-order sum-frequency generation (SFG) and third-order coherent Raman scattering (CRS) techniques, offer several improved imaging capabilities over their linear precursors. Nonlinear vibrational microscopy features unprecedented vibrational imaging speeds, provides strategies for higher spatial resolution, and gives access to additional molecular parameters. These advances have turned vibrational microscopy into a premier tool for chemically dissecting live cells and tissues. This review discusses the molecular contrast of SFG and CRS microscopy and highlights several of the advanced imaging capabilities that have impacted biological and biomedical research. PMID:23245525

Overview of the Shuttle Imaging Radar-B preliminary scientific results

NASA Technical Reports Server (NTRS)

Elachi, C.; Cimino, J.; Settle, M.

1986-01-01

Data collected with the Shuttle Imaging Radar-B (SIR-B) on the October 5, 1985 Shuttle mission are discussed. The design and capabilities of the sensor which operates in a fixed illumination geometry and has incidence angles between 15 and 60 deg with 1 deg increments are described. Problems encountered with the SIR-B during the mission are examined. the The radar stereo imaging capability of the sensor was verified and three-dimensional images of the earth surface were obtained. The oceanography experiments provided significant data on ocean wave and internal wave patterns, oil spills, and ice zones. The geological images revealed that the sensor can evaluate penetration effect in dry soil from buried receivers and the existence of subsurface dry channels in the Egyptian desert was validated. The use of multiincidence angle imaging to classify terrain units and derive vegetation maps and the development of terrain maps are confirmed.

Hand-held optical imager (Gen-2): improved instrumentation and target detectability

PubMed Central

Gonzalez, Jean; DeCerce, Joseph; Erickson, Sarah J.; Martinez, Sergio L.; Nunez, Annie; Roman, Manuela; Traub, Barbara; Flores, Cecilia A.; Roberts, Seigbeh M.; Hernandez, Estrella; Aguirre, Wenceslao; Kiszonas, Richard

2012-01-01

Abstract. Hand-held optical imagers are developed by various researchers towards reflectance-based spectroscopic imaging of breast cancer. Recently, a Gen-1 handheld optical imager was developed with capabilities to perform two-dimensional (2-D) spectroscopic as well as three-dimensional (3-D) tomographic imaging studies. However, the imager was bulky with poor surface contact (∼30%) along curved tissues, and limited sensitivity to detect targets consistently. Herein, a Gen-2 hand-held optical imager that overcame the above limitations of the Gen-1 imager has been developed and the instrumentation described. The Gen-2 hand-held imager is less bulky, portable, and has improved surface contact (∼86%) on curved tissues. Additionally, the forked probe head design is capable of simultaneous bilateral reflectance imaging of both breast tissues, and also transillumination imaging of a single breast tissue. Experimental studies were performed on tissue phantoms to demonstrate the improved sensitivity in detecting targets using the Gen-2 imager. The improved instrumentation of the Gen-2 imager allowed detection of targets independent of their location with respect to the illumination points, unlike in Gen-1 imager. The developed imager has potential for future clinical breast imaging with enhanced sensitivity, via both reflectance and transillumination imaging. PMID:23224163

CubeSat Nighttime Earth Observations

NASA Astrophysics Data System (ADS)

Pack, D. W.; Hardy, B. S.; Longcore, T.

2017-12-01

Satellite monitoring of visible emissions at night has been established as a useful capability for environmental monitoring and mapping the global human footprint. Pioneering work using Defense Meteorological Support Program (DMSP) sensors has been followed by new work using the more capable Visible Infrared Imaging Radiometer Suite (VIIRS). Beginning in 2014, we have been investigating the ability of small visible light cameras on CubeSats to contribute to nighttime Earth science studies via point-and-stare imaging. This paper summarizes our recent research using a common suite of simple visible cameras on several AeroCube satellites to carry out nighttime observations of urban areas and natural gas flares, nighttime weather (including lighting), and fishing fleet lights. Example results include: urban image examples, the utility of color imagery, urban lighting change detection, and multi-frame sequences imaging nighttime weather and large ocean areas with extensive fishing vessel lights. Our results show the potential for CubeSat sensors to improve monitoring of urban growth, light pollution, energy usage, the urban-wildland interface, the improvement of electrical power grids in developing countries, light-induced fisheries, and oil industry flare activity. In addition to orbital results, the nighttime imaging capabilities of new CubeSat sensors scheduled for launch in October 2017 are discussed.

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems.

PubMed

Glover, Jack L; Hudson, Lawrence T

2016-06-01

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in a US national aviation security standard.

Design of a novel class of protein-based magnetic resonance imaging contrast agents for the molecular imaging of cancer biomarkers

PubMed Central

Xue, Shenghui; Qiao, Jingjuan; Pu, Fan; Cameron, Mathew; Yang, Jenny J.

2014-01-01

Magnetic resonance imaging (MRI) of disease biomarkers, especially cancer biomarkers, could potentially improve our understanding of the disease and drug activity during preclinical and clinical drug treatment and patient stratification. MRI contrast agents with high relaxivity and targeting capability to tumor biomarkers are highly required. Extensive work has been done to develop MRI contrast agents. However, only a few limited literatures report that protein residues can function as ligands to bind Gd3+ with high binding affinity, selectivity, and relaxivity. In this paper, we focus on reporting our current progress on designing a novel class of protein-based Gd3+ MRI contrast agents (ProCAs) equipped with several desirable capabilities for in vivo application of MRI of tumor biomarkers. We will first discuss our strategy for improving the relaxivity by a novel protein-based design. We then discuss the effect of increased relaxivity of ProCAs on improving the detection limits for MRI contrast agent, especially for in vivo application. We will further report our efforts to improve in vivo imaging capability and our achievement in molecular imaging of cancer biomarkers with potential preclinical and clinical applications. PMID:23335551

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems

PubMed Central

Glover, Jack L.; Hudson, Lawrence T.

2016-01-01

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in a US national aviation security standard. PMID:27499586

An objectively-analyzed method for measuring the useful penetration of x-ray imaging systems

NASA Astrophysics Data System (ADS)

Glover, Jack L.; Hudson, Lawrence T.

2016-06-01

The ability to detect wires is an important capability of the cabinet x-ray imaging systems that are used in aviation security as well as the portable x-ray systems that are used by domestic law enforcement and military bomb squads. A number of national and international standards describe methods for testing this capability using the so called useful penetration test metric, where wires are imaged behind different thicknesses of blocking material. Presently, these tests are scored based on human judgments of wire visibility, which are inherently subjective. We propose a new method in which the useful penetration capabilities of an x-ray system are objectively evaluated by an image processing algorithm operating on digital images of a standard test object. The algorithm advantageously applies the Radon transform for curve parameter detection that reduces the problem of wire detection from two dimensions to one. The sensitivity of the wire detection method is adjustable and we demonstrate how the threshold parameter can be set to give agreement with human-judged results. The method was developed to be used in technical performance standards and is currently under ballot for inclusion in an international aviation security standard.

Sonographic imaging of fetal tympanic rings.

PubMed

Leibovitz, Z; Egenburg, S; Bronshtein, M; Shapiro, I; Tepper, R; Malinger, G; Ohel, G

2013-11-01

To examine the feasibility of ultrasonographic imaging of fetal tympanic rings. This was an observational cohort study of 80 healthy fetuses in low-risk pregnancies, divided into four gestational-age subgroups (12, 16, 23 and 32 weeks), each comprising 20 consecutive fetuses. Tympanic ring visualization was achieved by two-dimensional and three-dimensional (3D) sonography. A standard algorithm for tympanic ring examination was constructed using 3D multiplanar reconstruction. The volume acquisition plane was directed to the inferolateral aspect of the fetal temporal bone. Transvaginal scans were carried out in the 12-week and 16-week subgroups, and transabdominal scans in the 23-week and 32-week subgroups. Study parameters included the inferomedial inclination angle (IMIA) of the tympanic ring relative to the vertical skull axis, the anteromedial inclination angle (AMIA) of the tympanic ring relative to the anteroposterior skull axis and the longest (LTRD) and shortest (STRD) tympanic ring diameter, the latter measured perpendicular to the LTRD. The feasibility of tympanic ring demonstration was assessed in each gestational-age subgroup. Tympanic rings appeared as round-oval, thin, echogenic structures in a plane tangential to the inferolateral surface of the fetal skull below the inferior border of the squamous part of the temporal bone. Higher demonstration rates were achieved in the 16-week and 23-week subgroups (90% and 80%, respectively) than in the others. LTRD and STRD each showed a linear correlation with gestational age (r = 0.96 for both measurements; P < 0.01). Mean IMIA ranged from 41.0 to 60.4° and mean AMIA from 17.3 to 23.4° across the different gestational-age subgroups. The malleal manubrium was observed only in examinations in the second half of pregnancy, appearing as a bright echo within the upper area of the tympanic ring in 56% (9/16) and 82% (9/11) of cases with tympanic ring imaging appropriate for measurement of the study parameters in the 23-week and 32-week subgroups, respectively. This is the first report of sonographic imaging of fetal tympanic rings and shows that this is feasible in the second trimester. We discuss the possible implications of our findings for the prenatal diagnosis of congenital hearing loss. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Evaluating the extent of cell death in 3D high frequency ultrasound by registration with whole-mount tumor histopathology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vlad, Roxana M.; Kolios, Michael C.; Moseley, Joanne L.

Purpose: High frequency ultrasound imaging, 10-30 MHz, has the capability to assess tumor response to radiotherapy in mouse tumors as early as 24 h after treatment administration. The advantage of this technique is that the image contrast is generated by changes in the physical properties of dying cells. Therefore, a subject can be imaged before and multiple times during the treatment without the requirement of injecting specialized contrast agents. This study is motivated by a need to provide metrics of comparison between the volume and localization of cell death, assessed from histology, with the volume and localization of cell deathmore » surrogate, assessed as regions with increased echogeneity from ultrasound images. Methods: The mice were exposed to radiation doses of 2, 4, and 8 Gy. Ultrasound images were collected from each tumor before and 24 h after exposure to radiation using a broadband 25 MHz center frequency transducer. After radiotherapy, tumors exhibited hyperechoic regions in ultrasound images that corresponded to areas of cell death in histology. The ultrasound and histological images were rigidly registered. The tumors and regions of cell death were manually outlined on histological images. Similarly, the tumors and hyperechoic regions were outlined on the ultrasound images. Each set of contours was converted to a volumetric mesh in order to compare the volumes and the localization of cell death in histological and ultrasound images. Results: A shrinkage factor of 17{+-}2% was calculated from the difference in the tumor volumes evaluated from histological and ultrasound images. This was used to correct the tumor and cell death volumes assessed from histology. After this correction, the average absolute difference between the volume of cell death assessed from ultrasound and histological images was 11{+-}14% and the volume overlap was 70{+-}12%. Conclusions: The method provided metrics of comparison between the volume of cell death assessed from histology and that assessed from ultrasound images. It was applied here to evaluate the capability of ultrasound imaging to assess early tumor response to radiotherapy in mouse tumors. Similarly, it can be applied in the future to evaluate the capability of ultrasound imaging to assess early tumor response to other modalities of cancer treatment. The study contributes to an understanding of the capabilities and limitation of ultrasound imaging at noninvasively detecting cell death. This provides a foundation for future developments regarding the use of ultrasound in preclinical and clinical applications to adapt treatments based on tumor response to cancer therapy.« less

Cross polarization optical coherence tomography for diagnosis of oral soft tissues

NASA Astrophysics Data System (ADS)

Gladkova, Natalia; Karabut, Maria; Kiseleva, Elena; Robakidze, Natalia; Muraev, Alexander; Fomina, Julia

2011-03-01

We consider the capabilities of cross-polarization OCT (CP OCT) focused on comparison of images resulting from cross-polarization and co-polarization scattering simultaneously for diagnosis of oral soft tissues. CP OCT was done for 35 patients with dental implants and 30 patients with inflammatory intestine diseases. Our study showed good diagnostic capabilities of CP OCT for detecting soft tissue pathology in the oral cavity. The cross-polarized images demonstrate the ability of tissue to depolarize. CP OCT demonstrates clinical capabilities for early diagnosis of inflammatory intestine diseases by the state of oral cavity mucosa and for early detection of gingivitis in patients above implant.

AstroImageJ: Image Processing and Photometric Extraction for Ultra-precise Astronomical Light Curves

NASA Astrophysics Data System (ADS)

Collins, Karen A.; Kielkopf, John F.; Stassun, Keivan G.; Hessman, Frederic V.

2017-02-01

ImageJ is a graphical user interface (GUI) driven, public domain, Java-based, software package for general image processing traditionally used mainly in life sciences fields. The image processing capabilities of ImageJ are useful and extendable to other scientific fields. Here we present AstroImageJ (AIJ), which provides an astronomy specific image display environment and tools for astronomy specific image calibration and data reduction. Although AIJ maintains the general purpose image processing capabilities of ImageJ, AIJ is streamlined for time-series differential photometry, light curve detrending and fitting, and light curve plotting, especially for applications requiring ultra-precise light curves (e.g., exoplanet transits). AIJ reads and writes standard Flexible Image Transport System (FITS) files, as well as other common image formats, provides FITS header viewing and editing, and is World Coordinate System aware, including an automated interface to the astrometry.net web portal for plate solving images. AIJ provides research grade image calibration and analysis tools with a GUI driven approach, and easily installed cross-platform compatibility. It enables new users, even at the level of undergraduate student, high school student, or amateur astronomer, to quickly start processing, modeling, and plotting astronomical image data with one tightly integrated software package.

An aviation security (AVSEC) screening demonstrator for the detection of non-metallic threats at 28-33 GHz

NASA Astrophysics Data System (ADS)

Salmon, Neil A.; Bowring, Nick; Hutchinson, Simon; Southgate, Matthew; O'Reilly, Dean

2013-10-01

The unique selling proposition of millimetre wave technology for security screening is that it provides a stand-off or portal scenario sensing capability for non-metallic threats. The capabilities to detect some non-metallic threats are investigated in this paper, whilst recommissioning the AVSEC portal screening system at the Manchester Metropolitan University. The AVSEC system is a large aperture (1.6 m) portal screening imager which uses spatially incoherent illumination at 28-33 GHz from mode scrambling cavities to illuminate the subject. The imaging capability is critically analysed in terms of this illumination. A novel technique for the measurement of reflectance, refractive index and extinction coefficient is investigated and this then use to characterise the signatures of nitromethane, hexane, methanol, bees wax and baking flour. Millimetre wave images are shown how these liquids in polycarbonate bottles and the other materials appear against the human body.

Intramolecular bonds resolved on a semiconductor surface

NASA Astrophysics Data System (ADS)

Sweetman, Adam; Jarvis, Samuel P.; Rahe, Philipp; Champness, Neil R.; Kantorovich, Lev; Moriarty, Philip

2014-10-01

Noncontact atomic force microscopy (NC-AFM) is now routinely capable of obtaining submolecular resolution, readily resolving the carbon backbone structure of planar organic molecules adsorbed on metal substrates. Here we show that the same resolution may also be obtained for molecules adsorbed on a reactive semiconducting substrate. Surprisingly, this resolution is routinely obtained without the need for deliberate tip functionalization. Intriguingly, we observe two chemically distinct apex types capable of submolecular imaging. We characterize our tip apices by "inverse imaging" of the silicon adatoms of the Si (111)-7×7 surface and support our findings with detailed density functional theory (DFT) calculations. We also show that intramolecular resolution on individual molecules may be readily obtained at 78 K, rather than solely at 5 K as previously demonstrated. Our results suggest a wide range of tips may be capable of producing intramolecular contrast for molecules adsorbed on semiconductor surfaces, leading to a much broader applicability for submolecular imaging protocols.

Structured-illumination reflectance imaging coupled with spiral phase transform for bruise detection and three-dimensional geometry reconstruction of apples

USDA-ARS?s Scientific Manuscript database

Structured-illumination reflectance imaging (SIRI) is a new, promising imaging technique with enhanced, versatile capabilities for quality evaluation of food products. SIRI enables simultaneous acquisition of higher-contrast/resolution and better depth-controlled intensity and phase images for detec...

Radiography by selective detection of scatter field velocity components

NASA Technical Reports Server (NTRS)

Dugan, Edward T. (Inventor); Jacobs, Alan M. (Inventor); Shedlock, Daniel (Inventor)

2007-01-01

A reconfigurable collimated radiation detector, system and related method includes at least one collimated radiation detector. The detector has an adjustable collimator assembly including at least one feature, such as a fin, optically coupled thereto. Adjustments to the adjustable collimator selects particular directions of travel of scattered radiation emitted from an irradiated object which reach the detector. The collimated detector is preferably a collimated detector array, where the collimators are independently adjustable. The independent motion capability provides the capability to focus the image by selection of the desired scatter field components. When an array of reconfigurable collimated detectors is provided, separate image data can be obtained from each of the detectors and the respective images cross-correlated and combined to form an enhanced image.

Field Geology/Processes

NASA Technical Reports Server (NTRS)

Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

1996-01-01

The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

Multimodality hard-x-ray imaging of a chromosome with nanoscale spatial resolution

DOE PAGES

Yan, Hanfei; Nazaretski, Evgeny; Lauer, Kenneth R.; ...

2016-02-05

Here, we developed a scanning hard x-ray microscope using a new class of x-ray nano-focusing optic called a multilayer Laue lens and imaged a chromosome with nanoscale spatial resolution. The combination of the hard x-ray's superior penetration power, high sensitivity to elemental composition, high spatial-resolution and quantitative analysis creates a unique tool with capabilities that other microscopy techniques cannot provide. Using this microscope, we simultaneously obtained absorption-, phase-, and fluorescence-contrast images of Pt-stained human chromosome samples. The high spatial-resolution of the microscope and its multi-modality imaging capabilities enabled us to observe the internal ultra-structures of a thick chromosome without sectioningmore » it.« less

Multimodality hard-x-ray imaging of a chromosome with nanoscale spatial resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Hanfei; Nazaretski, Evgeny; Lauer, Kenneth R.

Here, we developed a scanning hard x-ray microscope using a new class of x-ray nano-focusing optic called a multilayer Laue lens and imaged a chromosome with nanoscale spatial resolution. The combination of the hard x-ray's superior penetration power, high sensitivity to elemental composition, high spatial-resolution and quantitative analysis creates a unique tool with capabilities that other microscopy techniques cannot provide. Using this microscope, we simultaneously obtained absorption-, phase-, and fluorescence-contrast images of Pt-stained human chromosome samples. The high spatial-resolution of the microscope and its multi-modality imaging capabilities enabled us to observe the internal ultra-structures of a thick chromosome without sectioningmore » it.« less

Optically sectioned in vivo imaging with speckle illumination HiLo microscopy

PubMed Central

Lim, Daryl; Ford, Tim N.; Chu, Kengyeh K.; Mertz, Jerome

2011-01-01

We present a simple wide-field imaging technique, called HiLo microscopy, that is capable of producing optically sectioned images in real time, comparable in quality to confocal laser scanning microscopy. The technique is based on the fusion of two raw images, one acquired with speckle illumination and another with standard uniform illumination. The fusion can be numerically adjusted, using a single parameter, to produce optically sectioned images of varying thicknesses with the same raw data. Direct comparison between our HiLo microscope and a commercial confocal laser scanning microscope is made on the basis of sectioning strength and imaging performance. Specifically, we show that HiLo and confocal 3-D imaging of a GFP-labeled mouse brain hippocampus are comparable in quality. Moreover, HiLo microscopy is capable of faster, near video rate imaging over larger fields of view than attainable with standard confocal microscopes. The goal of this paper is to advertise the simplicity, robustness, and versatility of HiLo microscopy, which we highlight with in vivo imaging of common model organisms including planaria, C. elegans, and zebrafish. PMID:21280920

Optically sectioned in vivo imaging with speckle illumination HiLo microscopy.

PubMed

Lim, Daryl; Ford, Tim N; Chu, Kengyeh K; Mertz, Jerome

2011-01-01

We present a simple wide-field imaging technique, called HiLo microscopy, that is capable of producing optically sectioned images in real time, comparable in quality to confocal laser scanning microscopy. The technique is based on the fusion of two raw images, one acquired with speckle illumination and another with standard uniform illumination. The fusion can be numerically adjusted, using a single parameter, to produce optically sectioned images of varying thicknesses with the same raw data. Direct comparison between our HiLo microscope and a commercial confocal laser scanning microscope is made on the basis of sectioning strength and imaging performance. Specifically, we show that HiLo and confocal 3-D imaging of a GFP-labeled mouse brain hippocampus are comparable in quality. Moreover, HiLo microscopy is capable of faster, near video rate imaging over larger fields of view than attainable with standard confocal microscopes. The goal of this paper is to advertise the simplicity, robustness, and versatility of HiLo microscopy, which we highlight with in vivo imaging of common model organisms including planaria, C. elegans, and zebrafish.

Optically sectioned in vivo imaging with speckle illumination HiLo microscopy

NASA Astrophysics Data System (ADS)

Lim, Daryl; Ford, Tim N.; Chu, Kengyeh K.; Mertz, Jerome

2011-01-01

We present a simple wide-field imaging technique, called HiLo microscopy, that is capable of producing optically sectioned images in real time, comparable in quality to confocal laser scanning microscopy. The technique is based on the fusion of two raw images, one acquired with speckle illumination and another with standard uniform illumination. The fusion can be numerically adjusted, using a single parameter, to produce optically sectioned images of varying thicknesses with the same raw data. Direct comparison between our HiLo microscope and a commercial confocal laser scanning microscope is made on the basis of sectioning strength and imaging performance. Specifically, we show that HiLo and confocal 3-D imaging of a GFP-labeled mouse brain hippocampus are comparable in quality. Moreover, HiLo microscopy is capable of faster, near video rate imaging over larger fields of view than attainable with standard confocal microscopes. The goal of this paper is to advertise the simplicity, robustness, and versatility of HiLo microscopy, which we highlight with in vivo imaging of common model organisms including planaria, C. elegans, and zebrafish.

True color blood flow imaging using a high-speed laser photography system

NASA Astrophysics Data System (ADS)

Liu, Chien-Sheng; Lin, Cheng-Hsien; Sun, Yung-Nien; Ho, Chung-Liang; Hsu, Chung-Chi

2012-10-01

Physiological changes in the retinal vasculature are commonly indicative of such disorders as diabetic retinopathy, glaucoma, and age-related macular degeneration. Thus, various methods have been developed for noninvasive clinical evaluation of ocular hemodynamics. However, to the best of our knowledge, current ophthalmic instruments do not provide a true color blood flow imaging capability. Accordingly, we propose a new method for the true color imaging of blood flow using a high-speed pulsed laser photography system. In the proposed approach, monochromatic images of the blood flow are acquired using a system of three cameras and three color lasers (red, green, and blue). A high-quality true color image of the blood flow is obtained by assembling the monochromatic images by means of image realignment and color calibration processes. The effectiveness of the proposed approach is demonstrated by imaging the flow of mouse blood within a microfluidic channel device. The experimental results confirm the proposed system provides a high-quality true color blood flow imaging capability, and therefore has potential for noninvasive clinical evaluation of ocular hemodynamics.

Embedding intensity image into a binary hologram with strong noise resistant capability

NASA Astrophysics Data System (ADS)

Zhuang, Zhaoyong; Jiao, Shuming; Zou, Wenbin; Li, Xia

2017-11-01

A digital hologram can be employed as a host image for image watermarking applications to protect information security. Past research demonstrates that a gray level intensity image can be embedded into a binary Fresnel hologram by error diffusion method or bit truncation coding method. However, the fidelity of the retrieved watermark image from binary hologram is generally not satisfactory, especially when the binary hologram is contaminated with noise. To address this problem, we propose a JPEG-BCH encoding method in this paper. First, we employ the JPEG standard to compress the intensity image into a binary bit stream. Next, we encode the binary bit stream with BCH code to obtain error correction capability. Finally, the JPEG-BCH code is embedded into the binary hologram. By this way, the intensity image can be retrieved with high fidelity by a BCH-JPEG decoder even if the binary hologram suffers from serious noise contamination. Numerical simulation results show that the image quality of retrieved intensity image with our proposed method is superior to the state-of-the-art work reported.

Enhanced tactical radar correlator (ETRAC): true interoperability of the 1990s

NASA Astrophysics Data System (ADS)

Guillen, Frank J.

1994-10-01

The enhanced tactical radar correlator (ETRAC) system is under development at Westinghouse Electric Corporation for the Army Space Program Office (ASPO). ETRAC is a real-time synthetic aperture radar (SAR) processing system that provides tactical IMINT to the corps commander. It features an open architecture comprised of ruggedized commercial-off-the-shelf (COTS), UNIX based workstations and processors. The architecture features the DoD common SAR processor (CSP), a multisensor computing platform to accommodate a variety of current and future imaging needs. ETRAC's principal functions include: (1) Mission planning and control -- ETRAC provides mission planning and control for the U-2R and ASARS-2 sensor, including capability for auto replanning, retasking, and immediate spot. (2) Image formation -- the image formation processor (IFP) provides the CPU intensive processing capability to produce real-time imagery for all ASARS imaging modes of operation. (3) Image exploitation -- two exploitation workstations are provided for first-phase image exploitation, manipulation, and annotation. Products include INTEL reports, annotated NITF SID imagery, high resolution hard copy prints and targeting data. ETRAC is transportable via two C-130 aircraft, with autonomous drive on/off capability for high mobility. Other autonomous capabilities include rapid setup/tear down, extended stand-alone support, internal environmental control units (ECUs) and power generation. ETRAC's mission is to provide the Army field commander with accurate, reliable, and timely imagery intelligence derived from collections made by the ASARS-2 sensor, located on-board the U-2R aircraft. To accomplish this mission, ETRAC receives video phase history (VPH) directly from the U-2R aircraft and converts it in real time into soft copy imagery for immediate exploitation and dissemination to the tactical users.

Confidence range estimate of extended source imagery acquisition algorithms via computer simulations. [in optical communication systems

NASA Technical Reports Server (NTRS)

Chen, CHIEN-C.; Hui, Elliot; Okamoto, Garret

1992-01-01

Spatial acquisition using the sun-lit Earth as a beacon source provides several advantages over active beacon-based systems for deep-space optical communication systems. However, since the angular extend of the Earth image is large compared to the laser beam divergence, the acquisition subsystem must be capable of resolving the image to derive the proper pointing orientation. The algorithms used must be capable of deducing the receiver location given the blurring introduced by the imaging optics and the large Earth albedo fluctuation. Furthermore, because of the complexity of modelling the Earth and the tracking algorithms, an accurate estimate of the algorithm accuracy can only be made via simulation using realistic Earth images. An image simulator was constructed for this purpose, and the results of the simulation runs are reported.

Resolution enhancement in integral microscopy by physical interpolation.

PubMed

Llavador, Anabel; Sánchez-Ortiga, Emilio; Barreiro, Juan Carlos; Saavedra, Genaro; Martínez-Corral, Manuel

2015-08-01

Integral-imaging technology has demonstrated its capability for computing depth images from the microimages recorded after a single shot. This capability has been shown in macroscopic imaging and also in microscopy. Despite the possibility of refocusing different planes from one snap-shot is crucial for the study of some biological processes, the main drawback in integral imaging is the substantial reduction of the spatial resolution. In this contribution we report a technique, which permits to increase the two-dimensional spatial resolution of the computed depth images in integral microscopy by a factor of √2. This is made by a double-shot approach, carried out by means of a rotating glass plate, which shifts the microimages in the sensor plane. We experimentally validate the resolution enhancement as well as we show the benefit of applying the technique to biological specimens.

Imaging modes of atomic force microscopy for application in molecular and cell biology.

PubMed

Dufrêne, Yves F; Ando, Toshio; Garcia, Ricardo; Alsteens, David; Martinez-Martin, David; Engel, Andreas; Gerber, Christoph; Müller, Daniel J

2017-04-06

Atomic force microscopy (AFM) is a powerful, multifunctional imaging platform that allows biological samples, from single molecules to living cells, to be visualized and manipulated. Soon after the instrument was invented, it was recognized that in order to maximize the opportunities of AFM imaging in biology, various technological developments would be required to address certain limitations of the method. This has led to the creation of a range of new imaging modes, which continue to push the capabilities of the technique today. Here, we review the basic principles, advantages and limitations of the most common AFM bioimaging modes, including the popular contact and dynamic modes, as well as recently developed modes such as multiparametric, molecular recognition, multifrequency and high-speed imaging. For each of these modes, we discuss recent experiments that highlight their unique capabilities.

Resolution enhancement in integral microscopy by physical interpolation

PubMed Central

Llavador, Anabel; Sánchez-Ortiga, Emilio; Barreiro, Juan Carlos; Saavedra, Genaro; Martínez-Corral, Manuel

2015-01-01

Integral-imaging technology has demonstrated its capability for computing depth images from the microimages recorded after a single shot. This capability has been shown in macroscopic imaging and also in microscopy. Despite the possibility of refocusing different planes from one snap-shot is crucial for the study of some biological processes, the main drawback in integral imaging is the substantial reduction of the spatial resolution. In this contribution we report a technique, which permits to increase the two-dimensional spatial resolution of the computed depth images in integral microscopy by a factor of √2. This is made by a double-shot approach, carried out by means of a rotating glass plate, which shifts the microimages in the sensor plane. We experimentally validate the resolution enhancement as well as we show the benefit of applying the technique to biological specimens. PMID:26309749

Microscopy image segmentation tool: Robust image data analysis

NASA Astrophysics Data System (ADS)

Valmianski, Ilya; Monton, Carlos; Schuller, Ivan K.

2014-03-01

We present a software package called Microscopy Image Segmentation Tool (MIST). MIST is designed for analysis of microscopy images which contain large collections of small regions of interest (ROIs). Originally developed for analysis of porous anodic alumina scanning electron images, MIST capabilities have been expanded to allow use in a large variety of problems including analysis of biological tissue, inorganic and organic film grain structure, as well as nano- and meso-scopic structures. MIST provides a robust segmentation algorithm for the ROIs, includes many useful analysis capabilities, and is highly flexible allowing incorporation of specialized user developed analysis. We describe the unique advantages MIST has over existing analysis software. In addition, we present a number of diverse applications to scanning electron microscopy, atomic force microscopy, magnetic force microscopy, scanning tunneling microscopy, and fluorescent confocal laser scanning microscopy.

Evaluation of state-of-the-art imaging systems for in vivo monitoring of retinal structure in mice: current capabilities and limitations

NASA Astrophysics Data System (ADS)

Zhang, Pengfei; Zam, Azhar; Pugh, Edward N.; Zawadzki, Robert J.

2014-02-01

Animal models of human diseases play an important role in studying and advancing our understanding of these conditions, allowing molecular level studies of pathogenesis as well as testing of new therapies. Recently several non-invasive imaging modalities including Fundus Camera, Scanning Laser Ophthalmoscopy (SLO) and Optical Coherence Tomography (OCT) have been successfully applied to monitor changes in the retinas of the living animals in experiments in which a single animal is followed over a portion of its lifespan. Here we evaluate the capabilities and limitations of these three imaging modalities for visualization of specific structures in the mouse eye. Example images acquired from different types of mice are presented. Future directions of development for these instruments and potential advantages of multi-modal imaging systems are discussed as well.

Methods for increasing the sensitivity of gamma-ray imagers

DOEpatents

Mihailescu, Lucian [Pleasanton, CA; Vetter, Kai M [Alameda, CA; Chivers, Daniel H [Fremont, CA

2012-02-07

Methods are presented that increase the position resolution and granularity of double sided segmented semiconductor detectors. These methods increase the imaging resolution capability of such detectors, either used as Compton cameras, or as position sensitive radiation detectors in imagers such as SPECT, PET, coded apertures, multi-pinhole imagers, or other spatial or temporal modulated imagers.

Systems for increasing the sensitivity of gamma-ray imagers

DOEpatents

Mihailescu, Lucian; Vetter, Kai M.; Chivers, Daniel H.

2012-12-11

Systems that increase the position resolution and granularity of double sided segmented semiconductor detectors are provided. These systems increase the imaging resolution capability of such detectors, either used as Compton cameras, or as position sensitive radiation detectors in imagers such as SPECT, PET, coded apertures, multi-pinhole imagers, or other spatial or temporal modulated imagers.

Implementation and assessment of an animal management system for small-animal micro-CT / micro-SPECT imaging

NASA Astrophysics Data System (ADS)

Holdsworth, David W.; Detombe, Sarah A.; Chiodo, Chris; Fricke, Stanley T.; Drangova, Maria

2011-03-01

Advances in laboratory imaging systems for CT, SPECT, MRI, and PET facilitate routine micro-imaging during pre-clinical investigations. Challenges still arise when dealing with immune-compromised animals, biohazardous agents, and multi-modality imaging. These challenges can be overcome with an appropriate animal management system (AMS), with the capability for supporting and monitoring a rat or mouse during micro-imaging. We report the implementation and assessment of a new AMS system for mice (PRA-3000 / AHS-2750, ASI Instruments, Warren MI), designed to be compatible with a commercial micro-CT / micro-SPECT imaging system (eXplore speCZT, GE Healthcare, London ON). The AMS was assessed under the following criteria: 1) compatibility with the imaging system (i.e. artifact generation, geometric dimensions); 2) compatibility with live animals (i.e. positioning, temperature regulation, anesthetic supply); 3) monitoring capabilities (i.e. rectal temperature, respiratory and cardiac monitoring); 4) stability of co-registration; and 5) containment. Micro-CT scans performed using a standardized live-animal protocol (90 kVp, 40 mA, 900 views, 16 ms per view) exhibited low noise (+/-19 HU) and acceptable artifact from high-density components within the AMS (e.g. ECG pad contacts). Live mice were imaged repeatedly (with removal and replacement of the AMS) and spatial registration was found to be stable to within +/-0.07 mm. All animals tolerated enclosure within the AMS for extended periods (i.e. > one hour) without distress, based on continuous recordings of rectal temperature, ECG waveform and respiratory rate. A sealed AMS system extends the capability of a conventional micro-imaging system to include immune-compromised and biosafety level 2 mouse-imaging protocols.

Biomechanical Analysis of Lateral Lumbar Interbody Fusion Constructs with Various Fixation Options: Based on a Validated Finite Element Model.

PubMed

Zhang, Zhenjun; Fogel, Guy R; Liao, Zhenhua; Sun, Yitao; Liu, Weiqiang

2018-06-01

Lateral lumbar interbody fusion using cage supplemented with fixation has been used widely in the treatment of lumbar disease. A combined fixation (CF) of lateral plate and spinous process plate may provide multiplanar stability similar to that of bilateral pedicle screws (BPS) and may reduce morbidity. The biomechanical influence of the CF on cage subsidence and facet joint stress has not been well described. The aim of this study was to compare biomechanics of various fixation options and to verify biomechanical effects of the CF. The surgical finite element models with various fixation options were constructed based on computed tomography images. The lateral plate and posterior spinous process plate were applied (CF). The 6 motion modes were simulated. Range of motion (ROM), cage stress, endplate stress, and facet joint stress were compared. For the CF model, ROM, cage stress, and endplate stress were the minimum in almost all motion modes. Compared with BPS, the CF reduced ROM, cage stress, and endplate stress in all motion modes. The ROM was reduced by more than 10% in all motion modes except for flexion; cage stress and endplate stress were reduced more than 10% in all motion modes except for rotation-left. After interbody fusion, facet joint stress was reduced substantially compared with the intact conditions in all motion modes except for flexion. The combined plate fixation may offer an alternative to BPS fixation in lateral lumbar interbody fusion. Copyright © 2018 Elsevier Inc. All rights reserved.

Pancreaticobiliary maljunction and biliary cancer.

PubMed

Kamisawa, Terumi; Kuruma, Sawako; Tabata, Taku; Chiba, Kazuro; Iwasaki, Susumu; Koizumi, Satomi; Kurata, Masanao; Honda, Goro; Itoi, Takao

2015-03-01

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall. Japanese clinical practice guidelines on how to deal with PBM were made in 2012, representing a world first. According to the 2013 revision to the diagnostic criteria for PBM, in addition to direct cholangiography, diagnosis can be made by magnetic resonance cholangiopancreatography (MRCP), 3-dimensional drip infusion cholangiography computed tomography, endoscopic ultrasonography (US), or multiplanar reconstruction images by multidetector row computed tomography. In PBM, the common channel is so long that sphincter action does not affect the pancreaticobiliary junction, and pancreatic juice frequently refluxes into the biliary tract. Persistence of refluxed pancreatic juice injures epithelium of the biliary tract and promotes cancer development, resulting in higher rates of carcinogenesis in the biliary tract. In a nationwide survey, biliary cancer was detected in 21.6% of adult patients with congenital biliary dilatation (bile duct cancer, 32.1% vs. gallbladder cancer, 62.3%) and in 42.4% of PBM patients without biliary dilatation (bile duct cancer, 7.3% vs. gallbladder cancer, 88.1%). Pathophysiological conditions due to pancreatobiliary reflux occur in patients with high confluence of pancreaticobiliary ducts, a common channel ≥6 mm long, and occlusion of communication during contraction of the sphincter. Once the diagnosis of PBM is established, immediate prophylactic surgery is recommended. However, the surgical strategy for PBM without biliary dilatation remains controversial. To detect PBM without biliary dilatation early, MRCP is recommended for patients showing gallbladder wall thickening on screening US under suspicion of PBM.

Brainstem ischemic lesions on MRI in children with tuberculous meningitis: with diffusion weighted confirmation.

PubMed

van der Merwe, Dirk Johannes; Andronikou, Savvas; Van Toorn, Ronald; Pienaar, Manana

2009-08-01

The Western Cape in South Africa has one of the highest incidences of tuberculous meningitis (TBM) in the world. Despite therapy, the outcome in children with advanced TBM remains dismal. Magnetic resonance imaging (MRI) has been shown to be superior to computed tomography (CT) in demonstrating ischemia in TBM, especially of the brainstem. The objective of this study was to characterize brainstem lesions and association with clinical findings in children with TBM by using MRI. CT and multiplanar MRI scans were performed in 30 children with proven TBM. From this group, a subgroup with radiological ischemic changes of the brainstem were identified. Radiological findings in these patients were then correlated with severity of disease, motor deficit, and outcome after 6 months. Radiological brainstem abnormalities were identified in 14 out of 30 children. Thirty-eight brainstem lesions were confirmed to be ischemic. The severity of disease at presentation, degree of motor deficit, and developmental outcome after 6 months of the children with ischemic brainstem lesions was poorer compared to those children without brainstem involvement. However, both sensitivity and specificity of the MRI brainstem lesion detection for clinical outcome proved low. A significant percentage of children with TBM have ischemic brainstem lesions. These are poorly visualized on conventional CT. MRI scanning is more sensitive in detecting these lesions and localizing them. There appears to be some association between MRI-detected brainstem lesions and clinical outcome. The exact meaning of these lesions and their implication for the patient's management require further clarification.

Initial experience with visualizing hand and foot tendons by dual-energy computed tomography.

PubMed

Deng, Kai; Sun, Cong; Liu, Cheng; Ma, Rui

2009-01-01

To assess the feasibility of visualizing hand and foot tendons by dual-energy computed tomography (CT). Twenty patients who suffered from hand or feet pains were scanned on dual-source CT (Definition, Forchheim, Germany) with dual-energy mode at tube voltages of 140 and 80 kV and a corresponding ratio of 1:4 between tube currents. The reconstructed images were postprocessed by volume rendering techniques (VRT) and multiplanar reconstruction (MPR). All of the suspected lesions were confirmed by surgery or follow-up studies. Twelve patients (total of 24 hands and feet, respectively) were found to be normal and the other eight patients (total of nine hands and feet, respectively) were found abnormal. Dual-energy techniques are very useful in visualizing tendons of the hands and feet, such as flexor pollicis longus tendon, flexor digitorum superficialis/profundus tendon, Achilles tendon, extensor hallucis longus tendon, and extensor digitorum longus tendon, etc. It can depict the whole shape of the tendons and their fixation points clearly. Peroneus longus tendon in the sole of the foot was not displayed very well. The distal ends of metacarpophalangeal joints with extensor digitoium tendon and extensor pollicis longus tendon were poorly shown. The lesions of tendons such as the circuitry, thickening, and adherence were also shown clearly. Dual-energy CT offers a new method to visualize tendons of the hand and foot. It could clearly display both anatomical structures and pathologic changes of hand and foot tendons.

Virtual tissue alignment and cutting plane definition – a new method to obtain optimal longitudinal histological sections

PubMed Central

Danz, J C; Habegger, M; Bosshardt, D D; Katsaros, C; Stavropoulos, A

2014-01-01

Histomorphometric evaluation of the buccal aspects of periodontal tissues in rodents requires reproducible alignment of maxillae and highly precise sections containing central sections of buccal roots; this is a cumbersome and technically sensitive process due to the small specimen size. The aim of the present report is to describe and analyze a method to transfer virtual sections of micro-computer tomographic (CT)-generated image stacks to the microtome for undecalcified histological processing and to describe the anatomy of the periodontium in rat molars. A total of 84 undecalcified sections of all buccal roots of seven untreated rats was analyzed. The accuracy of section coordinate transfer from virtual micro-CT slice to the histological slice, right–left side differences and the measurement error for linear and angular measurements on micro-CT and on histological micrographs were calculated using the Bland–Altman method, interclass correlation coefficient and the method of moments estimator. Also, manual alignment of the micro-CT-scanned rat maxilla was compared with multiplanar computer-reconstructed alignment. The supra alveolar rat anatomy is rather similar to human anatomy, whereas the alveolar bone is of compact type and the keratinized gingival epithelium bends apical to join the junctional epithelium. The high methodological standardization presented herein ensures retrieval of histological slices with excellent display of anatomical microstructures, in a reproducible manner, minimizes random errors, and thereby may contribute to the reduction of number of animals needed. PMID:24266502

Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI.

PubMed

Neubauer, Henning; Pabst, Thomas; Dick, Anke; Machann, Wolfram; Evangelista, Laura; Wirth, Clemens; Köstler, Herbert; Hahn, Dietbert; Beer, Meinrad

2013-01-01

Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease. To evaluate free-breathing DWI, as compared to contrast-enhanced MRI, in children, adolescents and young adults with Crohn disease. This retrospective study included 33 children and young adults with Crohn disease ages 17 ± 3 years (mean ± standard deviation) and 27 matched controls who underwent small-bowel MRI with contrast-enhanced T1-weighted sequences and DWI at 1.5 T. The detectability of Crohn manifestations was determined. Concurrent colonoscopy as reference was available in two-thirds of the children with Crohn disease. DWI and contrast-enhanced MRI correctly identified 32 and 31 patients, respectively. All 22 small-bowel lesions and all Crohn complications were detected. False-positive findings (two on DWI, one on contrast-enhanced MRI), compared to colonoscopy, were a result of large-bowel lumen collapse. Inflammatory wall thickening was comparable on DWI and contrast-enhanced MRI. DWI was superior to contrast-enhanced MRI for detection of lesions in 27% of the assessed bowel segments and equal to contrast-enhanced MRI in 71% of segments. DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition.

Aortic Elongation and Stanford B Dissection: The Tübingen Aortic Pathoanatomy (TAIPAN) Project.

PubMed

Lescan, M; Veseli, K; Oikonomou, A; Walker, T; Lausberg, H; Blumenstock, G; Bamberg, F; Schlensak, C; Krüger, T

2017-08-01

Aortic elongation has not yet been considered as a potential risk factor for Stanford type B dissection (TBD). The role of both aortic elongation and dilatation in patients with TBD was evaluated. The aortic morphology of a healthy control group (n = 236) and patients with TBD (n = 96) was retrospectively examined using three dimensional computed tomography imaging. Curved multiplanar reformats were used to examine aortic diameters at defined landmarks and aortic segment lengths. Diameters at all landmarks were significantly larger in the TBD group. The greatest diameter difference (56%) was measured in dissected descending aortas (p < .001). The segment with the most considerable difference between the study groups with regard to elongation was the non-dissected aortic arch of patients with TBD (36%; p < .001). Elongation in the aortic arch was accompanied by a diameter increase of 21% (p < .001). In receiver-operating curve analysis, the area under the curve was .85 for the diameter and .86 for the length of the aortic arch. In addition to dilatation, aortic arch elongation is associated with the development of TBD. The diameter and length of the non-dissected aortic arch may be predictive for TBD and may possibly be used for risk assessment in the future. This study provides the basis for further prospective evaluation of these parameters. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Micro-computed tomography of false starts produced on bone by different hand-saws.

PubMed

Pelletti, Guido; Viel, Guido; Fais, Paolo; Viero, Alessia; Visentin, Sindi; Miotto, Diego; Montisci, Massimo; Cecchetto, Giovanni; Giraudo, Chiara

2017-05-01

The analysis of macro- and microscopic characteristics of saw marks on bones can provide useful information about the class of the tool utilized to produce the injury. The aim of the present study was to test micro-computed tomography (micro-CT) for the analysis of false starts experimentally produced on 32 human bone sections using 4 different hand-saws in order to verify the potential utility of micro-CT for distinguishing false starts produced by different saws and to correlate the morphology of the tool with that of the bone mark. Each sample was analysed through stereomicroscopy and micro-CT. Stereomicroscopic analysis allowed the identification of the false starts and the detection of the number of tool marks left by each saw. Micro-CT scans, through the integration of 3D renders and multiplanar reconstructions (MPR), allowed the identification of the shape of each false start correlating it to the injuring tool. Our results suggest that micro-CT could be a useful technique for assessing false starts produced by different classes of saws, providing accurate morphological profiles of the bone marks with all the advantages of high resolution 3D imaging (e.g., high accuracy, non-destructive analysis, preservation and documentation of evidence). However, further studies are necessary to integrate qualitative data with quantitative metrical analysis in order to further characterize the false start and the related injuring tool. Copyright © 2017 Elsevier B.V. All rights reserved.

Sex determination of a Tunisian population by CT scan analysis of the skull.

PubMed

Zaafrane, Malek; Ben Khelil, Mehdi; Naccache, Ines; Ezzedine, Ekbel; Savall, Frédéric; Telmon, Norbert; Mnif, Najla; Hamdoun, Moncef

2018-05-01

It is widely accepted that the estimation of biological attributes in the human skeleton is more accurate when population-specific standards are applied. With the shortage of such data for contemporary North African populations, it is duly required to establish population-specific standards. We present here the first craniometric standards for sex determination of a contemporary Tunisian population. The aim of this study was to analyze the correlation between sex and metric parameters of the skull in this population using CT scan analysis and to generate proper reliable standards for sex determination of a complete or fragmented skull. The study sample comprised cranial multislice computed tomography scans of 510 individuals equally distributed by sex. ASIR TM software in a General Electric TM workstation was used to position 37 landmarks along the volume-rendered images and the multiplanar slices, defining 27 inter-landmark distances. Frontal and parietal bone thickness was also measured for each case. The data were analyzed using basic descriptive statistics and logistic regression with cross-validation of classification results. All of the measurements were sexually dimorphic with male values being higher than female values. A nine-variable model achieved the maximum classification accuracy of 90% with -2.9% sex bias and a six-variable model yielded 85.9% sexing accuracy with -0.97% sex bias. We conclude that the skull is highly dimorphic and represents a reliable bone for sex determination in contemporary Tunisian individuals.

CT evaluation of timing for ossification of the medial clavicular epiphysis in a contemporary Western Australian population.

PubMed

Franklin, Daniel; Flavel, Ambika

2015-05-01

The clavicle is the first bone to ossify in the developing embryo and the last to complete epiphyseal union. It is the latter sustained period of growth that has attracted the interest of skeletal biologists and forensic practitioners alike, who collectively recognize the important opportunity this bone affords to estimate skeletal age across the prenatal to early adult lifespan. Current research is largely directed towards evaluating the applicability of assessing fusion in the medial epiphysis, specifically for determining age of majority in the living. This study aims to contribute further insights, and inform medicolegal practice, by evaluating the Schmeling five-stage system for the assessment of clavicular development in a Western Australian population. We retrospectively evaluated high-resolution multiple detector computed tomography (MDCT) scans of 388 individuals (210 male; 178 female) between 10 and 35 years of age. Scans are viewed in axial and multiplanar reconstructed (MPR) images using OsiriX®. Fusion status is scored according to a five-stage system. Transition analysis is used to calculate age ranges and determine the mean age for transition between an unfused, fusing and fused status. The maximum likelihood estimates (in years) for transition from unfused to fusing is 20.60 (male) and 19.19 (female); transition from fusing to complete fusion is 21.92 (male) and 21.47 (female). Results of the present study confirm the reliability of the assessed method and demonstrate remarkable consistency to data reported for other global populations.

Highly versatile SPION encapsulated PLGA nanoparticles as photothermal ablators of cancer cells and as multimodal imaging agents.

PubMed

Sivakumar, Balasubramanian; Aswathy, Ravindran Girija; Romero-Aburto, Rebeca; Mitcham, Trevor; Mitchel, Keith A; Nagaoka, Yutaka; Bouchard, Richard R; Ajayan, Pulickel M; Maekawa, Toru; Sakthikumar, Dasappan Nair

2017-02-28

We have designed versatile polymeric nanoparticles with cancer cell specific targeting capabilities via aptamer conjugation after the successful encapsulation of curcumin and superparamagnetic iron oxide nanoparticles (SPIONs) inside a PLGA nanocapsule. These targeted nanocomposites were selectively taken up by tumor cells, under in vitro conditions, demonstrating the effectiveness of the aptamer targeting mechanism. Moreover, the nanocomposite potentially functioned as efficient multiprobes for optical, magnetic resonance imaging (MRI) and photoacoustic imaging contrast agents in the field of cancer diagnostics. The hyperthermic ability of these nanocomposites was mediated by SPIONs upon NIR-laser irradiation. In vitro cytotoxicity was shown by curcumin-loaded nanoparticles as well as the photothermal ablation of cancer cells mediated by the drug-encapsulated nanocomposite demonstrated the potential therapeutic effect of the nanocomposite. In short, we portray the aptamer-conjugated nanocomposite as a multimodal material capable of serving as a contrast agent for MR, photoacoustic and optical imaging. Furthermore, the nanocomposite functions as a targetable drug nanocarrier and a NIR-laser inducible hyperthermic material that is capable of ablating PANC-1 and MIA PaCa-2 cancer cell lines.

Ground-Based Measurement Experiment and First Results with Geosynchronous-Imaging Fourier Transform Spectrometer Engineering Demonstration Unit

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Smith, William L.; Bingham, Gail E.; Huppi, Ronald J.; Revercomb, Henry E.; Zollinger, Lori J.; Larar, Allen M.; Liu, Xu; Tansock, Joseph J.; Reisse, Robert A.;

Calibration Efforts and Unique Capabilities of the HST Space Telescope Imaging Spectrograph

NASA Astrophysics Data System (ADS)

Monroe, TalaWanda R.; Proffitt, Charles R.; Welty, Daniel; Branton, Doug; Carlberg, Joleen K.; debes, John Henry; Lockwood, Sean; Riley, Allyssa; Sohn, Sangmo Tony; Sonnentrucker, Paule G.; Walborn, Nolan R.; Jedrzejewski, Robert I.

2018-01-01

The Space Telescope Imaging Spectrograph (STIS) continues to offer the astronomy community the ability to carry out innovative UV and optical spectroscopic and imaging studies, two decades after its deployment on the Hubble Space Telescope (HST). Most notably, STIS provides spectroscopy in the FUV and NUV, including high spectral resolution echelle modes, imaging in the FUV, optical spectroscopy, and coronagraphic capabilities. Additionally, spatial scanning on the CCD with the long-slits is now possible to enable very high S/N spectroscopic observations without saturation while mitigating telluric and fringing concerns in the far red and near-IR. This new mode may especially benefit the diffuse interstellar bands and exoplanet transiting communities. We present recent calibration efforts for the instrument, including work to optimize the calibration of the echelle spectroscopic modes by improving the flux agreement of overlapping spectral orders affected by changes in the grating blaze function since HST Servicing Mission 4. We also discuss considerations to maintain the wavelength precision of the spectroscopic modes, and the current capabilities of CCD spectroscopic spatial trails.

The Multispectral Imaging Science Working Group. Volume 2: Working group reports

NASA Technical Reports Server (NTRS)

Cox, S. C. (Editor)

1982-01-01

Summaries of the various multispectral imaging science working groups are presented. Current knowledge of the spectral and spatial characteristics of the Earth's surface is outlined and the present and future capabilities of multispectral imaging systems are discussed.

MRI features after radiofrequency ablation of osteoid osteoma with cooled probes and impedance-control energy delivery.

PubMed

Cantwell, Colin P; Kerr, Jennifer; O'Byrne, John; Eustace, Stephen

2006-05-01

The purposes of our study were to determine the temporal changes in MR signal in bone after radiofrequency ablation of osteoid osteoma and the size of the zone of marrow signal change produced by the radiofrequency technique and to compare the size of the zone with published data for radiofrequency ablation with manual-control protocols. Radiofrequency ablation was performed in 10 patients with a clinical and radiologic diagnosis of osteoid osteoma. A cooled radiofrequency probe was inserted in the nidus. Twelve minutes of radiofrequency energy was applied from a 200-W radiofrequency generator in an impedance-control setting. MRI with multiplanar turbo spin-echo T1-weighted and STIR sequences was performed at 1, 7, and 28 days after the procedure in seven patients. The three remaining patients had follow-up imaging at 28 days only. The images were reviewed by two radiologists who categorized the imaging features and measured the marrow zone of signal alteration when visible. The size of the zone of marrow signal change produced by the radiofrequency technique was compared with published data for radiofrequency ablation with manual-control protocols. A 1-mm band of homogeneous altered marrow signal distributed symmetrically parallel to the entire probe tract was seen earliest, at 1 day, in the femoral neck lesion treated with the 2-cm probe. The band was low signal on the T1 sequence and high signal on the STIR sequence, and the diameter of the zone was 27 mm. By 7 days, five of the seven treated bones showed a band of marrow signal alteration. By 28 days, all 10 treated bones had a band of marrow signal alteration. The interband distance at 90 degrees to the probe measured on STIR images at 28 days was a mean of 20.9 mm (confidence interval, 16.1-25.7 mm [p < 0.05]; range +/- measurement error, 10.5-35 +/- 1.64 mm) with a 1-cm probe and 30.5 mm (measurement error, +/- 0.78 mm) on T1 images without contrast material when a 2-cm exposed-tip probe was used. Higher-output generators with impedance-control software and internally cooled radiofrequency probes with longer exposed tips produce larger zones of marrow signal change than expected with manual-control protocols. MRI allows detection of temporal marrow signal change after radiofrequency ablation. The marrow signal change with a high-energy delivery protocol is larger than manual-control protocols.

Motion at the Tibial and Polyethylene Component Interface in a Mobile-Bearing Total Ankle Replacement.

PubMed

Lundeen, Gregory A; Clanton, Thomas O; Dunaway, Linda J; Lu, Minggen

2016-08-01

Normal biomechanics of the ankle joint includes sagittal as well as axial rotation. Current understanding of mobile-bearing motion at the tibial-polyethylene interface in total ankle arthroplasty (TAA) is limited to anterior-posterior (AP) motion of the polyethylene component. The purpose of our study was to define the motion of the polyethylene component in relation to the tibial component in a mobile-bearing TAA in both the sagittal and axial planes in postoperative patients. Patients who were a minimum of 12 months postoperative from a third-generation mobile-bearing TAA were identified. AP images were saved at maximum internal and external rotation, and the lateral images were saved in maximum plantarflexion and dorsiflexion. Sagittal range of motion and AP translation of the polyethylene component were measured from the lateral images. Axial rotation was determined by measuring the relative position of the 2 wires within the polyethylene component on AP internal and external rotation imaging. This relationship was compared to a table developed from fluoroscopic images taken at standardized degrees of axial rotation of a nonimplanted polyethylene with the associated length relationship of the 2 imbedded wires. Sixteen patients were included in this investigation, 9 (56%) were male and average age was 68 (range, 49-80) years. Time from surgery averaged 25 (range, 12-38) months. Total sagittal range of motion averaged 23±9 (range, 9-33) degrees. Axial motion for total internal and external rotation of the polyethylene component on the tibial component averaged 6±5 (range, 0-18) degrees. AP translation of the polyethylene component relative to the tibial component averaged 1±1 (range, 0-3) mm. There was no relationship between axial rotation or AP translation of the polyethylene component and ankle joint range of motion (P > .05). To our knowledge, this is the first investigation to measure axial and sagittal motion of the polyethylene component at the tibial implant interface in patients following a mobile-bearing TAA. Based on outcome scores and range-of-motion measurements, we believe the patients in this study are a representative cross section of subjects compared to other TAA research results. The results from this investigation indicate the potential for a mobile-bearing TAA to fall within the parameters of normal polyaxial ankle motion. The multiplanar articulation in a mobile-bearing TAA may reduce excessively high peak pressures during the complex dynamic tibial and talar motion, which may have a positive influence on gait pattern, polyethylene wear, and implant longevity. Level IV, case series. © The Author(s) 2016.

Success of HIS DICOM interfaces in the integration of the healthcare enterprise at the Department of Veterans Affairs

NASA Astrophysics Data System (ADS)

Kuzmak, Peter M.; Dayhoff, Ruth E.

1999-07-01

The US Department of Veterans Affairs (VA) is integrating imaging into the healthcare enterprise using the Digital Imaging and Communication in Medicine (DICOM) standard protocols. Image management is directly integrated into the VistA Hospital Information System (HIS) software and the clinical database. Radiology images are acquired via DICOM, and are stored directly in the HIS database. Images can be displayed on low-cost clinician's workstations throughout the medical center. High-resolution diagnostic quality multi-monitor VistA workstations with specialized viewing software can be used for reading radiology images. Two approaches are used to acquire and handle imags within the radiology department. Some sties have a commercial Picture Archiving and Communications System (PACS) interfaced to the VistA HIS, while other sites use the direct image acquisition and integrated diagnostic reading capabilities of VistA itself. A small set of DICOM services have been implemented by VistA to allow patient and study text data to be transmitted to image producing modalities and the commercial PACS, and to enable images and study data to be transferred back. The VistA DICOM capabilities are now used to interface seven different commercial PACS products and over twenty different radiology modalities. The communications capabilities of DICOM and the VA wide area network are begin used to support reading of radiology images form remote sites. DICOM has been the cornerstone in the ability to integrate imaging functionality into the Healthcare Enterprise. Because of its openness, it allows the integration of system component from commercial and non- commercial sources to work together to provide functional cost-effective solutions. As DICOM expands to non-radiology devices, integration must occur with the specialty information subsystems that handle orders and reports, their associated DICOM image capture systems, and the computer- based patient record. The mode and concepts of the DICOM standard can be extended to these other areas, but some adjustments may be required.

Ultrashort electron pulses as a four-dimensional diagnosis of plasma dynamics.

PubMed

Zhu, P F; Zhang, Z C; Chen, L; Li, R Z; Li, J J; Wang, X; Cao, J M; Sheng, Z M; Zhang, J

2010-10-01

We report an ultrafast electron imaging system for real-time examination of ultrafast plasma dynamics in four dimensions. It consists of a femtosecond pulsed electron gun and a two-dimensional single electron detector. The device has an unprecedented capability of acquiring a high-quality shadowgraph image with a single ultrashort electron pulse, thus permitting the measurement of irreversible processes using a single-shot scheme. In a prototype experiment of laser-induced plasma of a metal target under moderate pump intensity, we demonstrated its unique capability of acquiring high-quality shadowgraph images on a micron scale with a-few-picosecond time resolution.

Digital Image Correlation Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Dan; Crozier, Paul; Reu, Phil

DICe is an open source digital image correlation (DIC) tool intended for use as a module in an external application or as a standalone analysis code. It's primary capability is computing full-field displacements and strains from sequences of digital These images are typically of a material sample undergoing a materials characterization experiment, but DICe is also useful for other applications (for example, trajectory tracking). DICe is machine portable (Windows, Linux and Mac) and can be effectively deployed on a high performance computing platform. Capabilities from DICe can be invoked through a library interface, via source code integration of DICe classesmore » or through a graphical user interface.« less

ImageX: new and improved image explorer for astronomical images and beyond

NASA Astrophysics Data System (ADS)

Hayashi, Soichi; Gopu, Arvind; Kotulla, Ralf; Young, Michael D.

2016-08-01

The One Degree Imager - Portal, Pipeline, and Archive (ODI-PPA) has included the Image Explorer interactive image visualization tool since it went operational. Portal users were able to quickly open up several ODI images within any HTML5 capable web browser, adjust the scaling, apply color maps, and perform other basic image visualization steps typically done on a desktop client like DS9. However, the original design of the Image Explorer required lossless PNG tiles to be generated and stored for all raw and reduced ODI images thereby taking up tens of TB of spinning disk space even though a small fraction of those images were being accessed by portal users at any given time. It also caused significant overhead on the portal web application and the Apache webserver used by ODI-PPA. We found it hard to merge in improvements made to a similar deployment in another project's portal. To address these concerns, we re-architected Image Explorer from scratch and came up with ImageX, a set of microservices that are part of the IU Trident project software suite, with rapid interactive visualization capabilities useful for ODI data and beyond. We generate a full resolution JPEG image for each raw and reduced ODI FITS image before producing a JPG tileset, one that can be rendered using the ImageX frontend code at various locations as appropriate within a web portal (for example: on tabular image listings, views allowing quick perusal of a set of thumbnails or other image sifting activities). The new design has decreased spinning disk requirements, uses AngularJS for the client side Model/View code (instead of depending on backend PHP Model/View/Controller code previously used), OpenSeaDragon to render the tile images, and uses nginx and a lightweight NodeJS application to serve tile images thereby significantly decreasing the Time To First Byte latency by a few orders of magnitude. We plan to extend ImageX for non-FITS images including electron microscopy and radiology scan images, and its featureset to include basic functions like image overlay and colormaps. Users needing more advanced visualization and analysis capabilities could use a desktop tool like DS9+IRAF on another IU Trident project called StarDock, without having to download Gigabytes of FITS image data.

Fast susceptibility-weighted imaging with three-dimensional short-axis propeller (SAP)-echo-planar imaging.

PubMed

Holdsworth, Samantha J; Yeom, Kristen W; Moseley, Michael E; Skare, S

2015-05-01

Susceptibility-weighted imaging (SWI) in neuroimaging can be challenging due to long scan times of three-dimensional (3D) gradient recalled echo (GRE), while faster techniques such as 3D interleaved echo-planar imaging (iEPI) are prone to motion artifacts. Here we outline and implement a 3D short-axis propeller echo-planar imaging (SAP-EPI) trajectory as a faster, motion-correctable approach for SWI. Experiments were conducted on a 3T MRI system. The 3D SAP-EPI, 3D iEPI, and 3D GRE SWI scans were acquired on two volunteers. Controlled motion experiments were conducted to test the motion-correction capability of 3D SAP-EPI. The 3D SAP-EPI SWI data were acquired on two pediatric patients as a potential alternative to 2D GRE used clinically. The 3D GRE images had a better target resolution (0.47 × 0.94 × 2 mm, scan time = 5 min), iEPI and SAP-EPI images (resolution = 0.94 × 0.94 × 2 mm) were acquired in a faster scan time (1:52 min) with twice the brain coverage. SAP-EPI showed motion-correction capability and some immunity to undersampling from rejected data. While 3D SAP-EPI suffers from some geometric distortion, its short scan time and motion-correction capability suggest that SAP-EPI may be a useful alternative to GRE and iEPI for use in SWI, particularly in uncooperative patients. © 2014 Wiley Periodicals, Inc.

VIP: Vortex Image Processing Package for High-contrast Direct Imaging

NASA Astrophysics Data System (ADS)

Gomez Gonzalez, Carlos Alberto; Wertz, Olivier; Absil, Olivier; Christiaens, Valentin; Defrère, Denis; Mawet, Dimitri; Milli, Julien; Absil, Pierre-Antoine; Van Droogenbroeck, Marc; Cantalloube, Faustine; Hinz, Philip M.; Skemer, Andrew J.; Karlsson, Mikael; Surdej, Jean

2017-07-01

We present the Vortex Image Processing (VIP) library, a python package dedicated to astronomical high-contrast imaging. Our package relies on the extensive python stack of scientific libraries and aims to provide a flexible framework for high-contrast data and image processing. In this paper, we describe the capabilities of VIP related to processing image sequences acquired using the angular differential imaging (ADI) observing technique. VIP implements functionalities for building high-contrast data processing pipelines, encompassing pre- and post-processing algorithms, potential source position and flux estimation, and sensitivity curve generation. Among the reference point-spread function subtraction techniques for ADI post-processing, VIP includes several flavors of principal component analysis (PCA) based algorithms, such as annular PCA and incremental PCA algorithms capable of processing big datacubes (of several gigabytes) on a computer with limited memory. Also, we present a novel ADI algorithm based on non-negative matrix factorization, which comes from the same family of low-rank matrix approximations as PCA and provides fairly similar results. We showcase the ADI capabilities of the VIP library using a deep sequence on HR 8799 taken with the LBTI/LMIRCam and its recently commissioned L-band vortex coronagraph. Using VIP, we investigated the presence of additional companions around HR 8799 and did not find any significant additional point source beyond the four known planets. VIP is available at http://github.com/vortex-exoplanet/VIP and is accompanied with Jupyter notebook tutorials illustrating the main functionalities of the library.

Health care using high-bandwidth communication to overcome distance and time barriers for the Department of Defense

NASA Astrophysics Data System (ADS)

Mun, Seong K.; Freedman, Matthew T.; Gelish, Anthony; de Treville, Robert E.; Sheehy, Monet R.; Hansen, Mark; Hill, Mac; Zacharia, Elisabeth; Sullivan, Michael J.; Sebera, C. Wayne

1993-01-01

Image management and communications (IMAC) network, also known as picture archiving and communication system (PACS) consists of (1) digital image acquisition, (2) image review station (3) image storage device(s), image reading workstation, and (4) communication capability. When these subsystems are integrated over a high speed communication technology, possibilities are numerous in improving the timeliness and quality of diagnostic services within a hospital or at remote clinical sites. Teleradiology system uses basically the same hardware configuration together with a long distance communication capability. Functional characteristics of components are highlighted. Many medical imaging systems are already in digital form. These digital images constitute approximately 30% of the total volume of images produced in a radiology department. The remaining 70% of images include conventional x-ray films of the chest, skeleton, abdomen, and GI tract. Unless one develops a method of handling these conventional film images, global improvement in productivity in image management and radiology service throughout a hospital cannot be achieved. Currently, there are two method of producing digital information representing these conventional analog images for IMAC: film digitizers that scan the conventional films, and computed radiography (CR) that captures x-ray images using storage phosphor plate that is subsequently scanned by a laser beam.

Computer-aided light sheet flow visualization using photogrammetry

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1994-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and a visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) results, was chosen to interactively display the reconstructed light sheet images with the numerical surface geometry for the model or aircraft under study. The photogrammetric reconstruction technique and the image processing and computer graphics techniques and equipment are described. Results of the computer-aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images with CFD solutions in the same graphics environment is also demonstrated.

Computer-Aided Light Sheet Flow Visualization

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1993-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

Computer-aided light sheet flow visualization

NASA Technical Reports Server (NTRS)

Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

1993-01-01

A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

Isotropic three-dimensional T2 mapping of knee cartilage: Development and validation.

PubMed

Colotti, Roberto; Omoumi, Patrick; Bonanno, Gabriele; Ledoux, Jean-Baptiste; van Heeswijk, Ruud B

2018-02-01

1) To implement a higher-resolution isotropic 3D T 2 mapping technique that uses sequential T 2 -prepared segmented gradient-recalled echo (Iso3DGRE) images for knee cartilage evaluation, and 2) to validate it both in vitro and in vivo in healthy volunteers and patients with knee osteoarthritis. The Iso3DGRE sequence with an isotropic 0.6 mm spatial resolution was developed on a clinical 3T MR scanner. Numerical simulations were performed to optimize the pulse sequence parameters. A phantom study was performed to validate the T 2 estimation accuracy. The repeatability of the sequence was assessed in healthy volunteers (n = 7). T 2 values were compared with those from a clinical standard 2D multislice multiecho (MSME) T 2 mapping sequence in knees of healthy volunteers (n = 13) and in patients with knee osteoarthritis (OA, n = 5). The numerical simulations resulted in 100 excitations per segment and an optimal radiofrequency (RF) excitation angle of 15°. The phantom study demonstrated a good correlation of the technique with the reference standard (slope 0.9 ± 0.05, intercept 0.2 ± 1.7 msec, R 2 ≥ 0.99). Repeated measurements of cartilage T 2 values in healthy volunteers showed a coefficient of variation of 5.6%. Both Iso3DGRE and MSME techniques found significantly higher cartilage T 2 values (P < 0.03) in OA patients. Iso3DGRE precision was equal to that of the MSME T 2 mapping in healthy volunteers, and significantly higher in OA (P = 0.01). This study successfully demonstrated that high-resolution isotropic 3D T 2 mapping for knee cartilage characterization is feasible, accurate, repeatable, and precise. The technique allows for multiplanar reformatting and thus T 2 quantification in any plane of interest. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:362-371. © 2017 International Society for Magnetic Resonance in Medicine.

Superior Canal Dehiscence Syndrome Affecting 3 Families.

PubMed

Heidenreich, Katherine D; Kileny, Paul R; Ahmed, Sameer; El-Kashlan, Hussam K; Melendez, Tori L; Basura, Gregory J; Lesperance, Marci M

2017-07-01

Superior canal dehiscence syndrome (SCDS) is an increasingly recognized cause of hearing loss and vestibular symptoms, but the etiology of this condition remains unknown. To describe 7 cases of SCDS across 3 families. This retrospective case series included 7 patients from 3 different families treated at a neurotology clinic at a tertiary academic medical center from 2010 to 2014. Patients were referred by other otolaryngologists or were self-referred. Each patient demonstrated unilateral or bilateral SCDS or near dehiscence. Clinical evaluation involved body mass index calculation, audiometry, cervical vestibular evoked myogenic potential testing, electrocochleography, and multiplanar computed tomographic (CT) scan of the temporal bones. Zygosity testing was performed on twin siblings. The diagnosis of SCDS was made if bone was absent over the superior semicircular canal on 2 consecutive CT images, in addition to 1 physiologic sign consistent with labyrinthine dehiscence. Near dehiscence was defined as absent bone on only 1 CT image but with symptoms and at least 1 physiologic sign of labyrinthine dehiscence. A total of 7 patients (5 female and 2 male; age range, 8-49 years) from 3 families underwent evaluation. Family A consisted of 3 adult first-degree relatives, of whom 2 were diagnosed with SCDS and 1 with near dehiscence. Family B included a mother and her child, both of whom were diagnosed with unilateral SCDS. Family C consisted of adult monozygotic twins, each of whom was diagnosed with unilateral SCDS. For all cases, dehiscence was located at the arcuate eminence. Obesity alone did not explain the occurrence of SCDS because 5 of the 7 cases had a body mass index (calculated as weight in kilograms divided by height in meters squared) less than 30.0. Superior canal dehiscence syndrome is a rare, often unrecognized condition. This report of 3 multiplex families with SCDS provides evidence in support of a potential genetic contribution to the etiology. Symptomatic first-degree relatives of patients diagnosed with SCDS should be offered evaluation to improve detection of this disorder.

Comparative Evaluation of Flow Quantification across the Atrioventricular Valve in Patients with Functional Univentricular Heart after Fontan's Surgery and Healthy Controls: Measurement by 4D Flow Magnetic Resonance Imaging and Streamline Visualization.

PubMed

She, Hoi Lam; Roest, Arno A W; Calkoen, Emmeline E; van den Boogaard, Pieter J; van der Geest, Rob J; Hazekamp, Mark G; de Roos, Albert; Westenberg, Jos J M

2017-01-01

To evaluate the inflow pattern and flow quantification in patients with functional univentricular heart after Fontan's operation using 4D flow magnetic resonance imaging (MRI) with streamline visualization when compared with the conventional 2D flow approach. Seven patients with functional univentricular heart after Fontan's operation and twenty-three healthy controls underwent 4D flow MRI. In two orthogonal two-chamber planes, streamline visualization was applied, and inflow angles with peak inflow velocity (PIV) were measured. Transatrioventricular flow quantification was assessed using conventional 2D multiplanar reformation (MPR) and 4D MPR tracking the annulus and perpendicular to the streamline inflow at PIV, and they were validated with net forward aortic flow. Inflow angles at PIV in the patient group demonstrated wide variation of angles and directions when compared with the control group (P < .01). The use of 4D flow MRI with streamlines visualization in quantification of the transatrioventricular flow had smaller limits of agreement (2.2 ± 4.1 mL; 95% limit of agreement -5.9-10.3 mL) when compared with the static plane assessment from 2DFlow MRI (-2.2 ± 18.5 mL; 95% limit of agreement agreement -38.5-34.1 mL). Stronger correlation was present in the 4D flow between the aortic and trans-atrioventricular flow (R 2 correlation in 4D flow: 0.893; in 2D flow: 0.786). Streamline visualization in 4D flow MRI confirmed variable atrioventricular inflow directions in patients with functional univentricular heart with previous Fontan's procedure. 4D flow aided generation of measurement planes according to the blood flood dynamics and has proven to be more accurate than the fixed plane 2D flow measurements when calculating flow quantifications. © 2016 Wiley Periodicals, Inc.

Is there a role for pre-operative contrast-enhanced magnetic resonance imaging for radical surgery in malignant pleural mesothelioma?

PubMed

Stewart, Duncan; Waller, David; Edwards, John; Jeyapalan, Kanagaratnam; Entwisle, James

2003-12-01

To assess the use of contrast-enhanced magnetic resonance imaging (CEMRI) in addition to computed tomography in the pre-operative assessment of patients for radical surgery in malignant pleural mesothelioma. Over a 45-month period, 51 of 76 patients assessed (69 men and seven women), underwent extra-pleural pneumonectomy or radical pleurectomy/decortication. Post-operative pathological stage was correlated with radiological staging, with particular emphasis on tumour resectability. Seventeen (22%) patients were found on CEMRI to have unresectable, but histologically unconfirmed disease, not previously seen on CT. Fifty-one (67%) patients proceeded to radical surgery, but pathological nodal data were incomplete in three, so excluding these patients from further analyses. The median pre-operative interval after CEMRI was 17 days. Two patients were found to have unexpectedly extensive disease at thoracotomy, thus the sensitivity of CEMRI for prediction of resectability was 97%. Using the International Mesothelioma Interest Group system, tumour stage was correctly predicted by CEMRI in 48% of patients, but understaged in 50% of cases, largely due to the underestimation of pericardial involvement, but this did not affect resectability and had no significant effect on prognosis. Nodal stage was correctly identified in 60% of patients. CEMRI was successful in predicting pathological tumour stage T3 or less (sensitivity of 85%; specificity of 100%), but less so in identifying tumour stage T2 or less (sensitivity of 23%; specificity of 96%) or N2 nodal disease (sensitivity 66%; specificity 73%). CEMRI is most useful in the differentiation of T3 and T4 disease and may be unnecessary at earlier stages. Its multiplanar tumour localisation abilities are of value in the assessment of resectability. It is unlikely to contribute significantly to nodal staging, but it remains a valuable adjunct in the selection of patients for radical surgery.

Method and Apparatus for Computed Imaging Backscatter Radiography

NASA Technical Reports Server (NTRS)

Shedlock, Daniel (Inventor); Sabri, Nissia (Inventor); Dugan, Edward T. (Inventor); Jacobs, Alan M. (Inventor); Meng, Christopher (Inventor)

2013-01-01

Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion.

Interactive Image Analysis System Design,

DTIC Science & Technology

1982-12-01

This report describes a design for an interactive image analysis system (IIAS), which implements terrain data extraction techniques. The design... analysis system. Additionally, the system is fully capable of supporting many generic types of image analysis and data processing, and is modularly...employs commercially available, state of the art minicomputers and image display devices with proven software to achieve a cost effective, reliable image

Establishment of Imaging Spectroscopy of Nuclear Gamma-Rays based on Geometrical Optics

PubMed Central

Tanimori, Toru; Mizumura, Yoshitaka; Takada, Atsushi; Miyamoto, Shohei; Takemura, Taito; Kishimoto, Tetsuro; Komura, Shotaro; Kubo, Hidetoshi; Kurosawa, Shunsuke; Matsuoka, Yoshihiro; Miuchi, Kentaro; Mizumoto, Tetsuya; Nakamasu, Yuma; Nakamura, Kiseki; Parker, Joseph D.; Sawano, Tatsuya; Sonoda, Shinya; Tomono, Dai; Yoshikawa, Kei

2017-01-01

Since the discovery of nuclear gamma-rays, its imaging has been limited to pseudo imaging, such as Compton Camera (CC) and coded mask. Pseudo imaging does not keep physical information (intensity, or brightness in Optics) along a ray, and thus is capable of no more than qualitative imaging of bright objects. To attain quantitative imaging, cameras that realize geometrical optics is essential, which would be, for nuclear MeV gammas, only possible via complete reconstruction of the Compton process. Recently we have revealed that “Electron Tracking Compton Camera” (ETCC) provides a well-defined Point Spread Function (PSF). The information of an incoming gamma is kept along a ray with the PSF and that is equivalent to geometrical optics. Here we present an imaging-spectroscopic measurement with the ETCC. Our results highlight the intrinsic difficulty with CCs in performing accurate imaging, and show that the ETCC surmounts this problem. The imaging capability also helps the ETCC suppress the noise level dramatically by ~3 orders of magnitude without a shielding structure. Furthermore, full reconstruction of Compton process with the ETCC provides spectra free of Compton edges. These results mark the first proper imaging of nuclear gammas based on the genuine geometrical optics. PMID:28155870

Establishment of Imaging Spectroscopy of Nuclear Gamma-Rays based on Geometrical Optics.

PubMed

Tanimori, Toru; Mizumura, Yoshitaka; Takada, Atsushi; Miyamoto, Shohei; Takemura, Taito; Kishimoto, Tetsuro; Komura, Shotaro; Kubo, Hidetoshi; Kurosawa, Shunsuke; Matsuoka, Yoshihiro; Miuchi, Kentaro; Mizumoto, Tetsuya; Nakamasu, Yuma; Nakamura, Kiseki; Parker, Joseph D; Sawano, Tatsuya; Sonoda, Shinya; Tomono, Dai; Yoshikawa, Kei

2017-02-03

Since the discovery of nuclear gamma-rays, its imaging has been limited to pseudo imaging, such as Compton Camera (CC) and coded mask. Pseudo imaging does not keep physical information (intensity, or brightness in Optics) along a ray, and thus is capable of no more than qualitative imaging of bright objects. To attain quantitative imaging, cameras that realize geometrical optics is essential, which would be, for nuclear MeV gammas, only possible via complete reconstruction of the Compton process. Recently we have revealed that "Electron Tracking Compton Camera" (ETCC) provides a well-defined Point Spread Function (PSF). The information of an incoming gamma is kept along a ray with the PSF and that is equivalent to geometrical optics. Here we present an imaging-spectroscopic measurement with the ETCC. Our results highlight the intrinsic difficulty with CCs in performing accurate imaging, and show that the ETCC surmounts this problem. The imaging capability also helps the ETCC suppress the noise level dramatically by ~3 orders of magnitude without a shielding structure. Furthermore, full reconstruction of Compton process with the ETCC provides spectra free of Compton edges. These results mark the first proper imaging of nuclear gammas based on the genuine geometrical optics.

Real-time intravascular photoacoustic-ultrasound imaging of lipid-laden plaque at speed of video-rate level

NASA Astrophysics Data System (ADS)

Hui, Jie; Cao, Yingchun; Zhang, Yi; Kole, Ayeeshik; Wang, Pu; Yu, Guangli; Eakins, Gregory; Sturek, Michael; Chen, Weibiao; Cheng, Ji-Xin

2017-03-01

Intravascular photoacoustic-ultrasound (IVPA-US) imaging is an emerging hybrid modality for the detection of lipidladen plaques by providing simultaneous morphological and lipid-specific chemical information of an artery wall. The clinical utility of IVPA-US technology requires real-time imaging and display at speed of video-rate level. Here, we demonstrate a compact and portable IVPA-US system capable of imaging at up to 25 frames per second in real-time display mode. This unprecedented imaging speed was achieved by concurrent innovations in excitation laser source, rotary joint assembly, 1 mm IVPA-US catheter, differentiated A-line strategy, and real-time image processing and display algorithms. By imaging pulsatile motion at different imaging speeds, 16 frames per second was deemed to be adequate to suppress motion artifacts from cardiac pulsation for in vivo applications. Our lateral resolution results further verified the number of A-lines used for a cross-sectional IVPA image reconstruction. The translational capability of this system for the detection of lipid-laden plaques was validated by ex vivo imaging of an atherosclerotic human coronary artery at 16 frames per second, which showed strong correlation to gold-standard histopathology.

Low-cost, high-speed back-end processing system for high-frequency ultrasound B-mode imaging.

PubMed

Chang, Jin Ho; Sun, Lei; Yen, Jesse T; Shung, K Kirk

2009-07-01

For real-time visualization of the mouse heart (6 to 13 beats per second), a back-end processing system involving high-speed signal processing functions to form and display images has been developed. This back-end system was designed with new signal processing algorithms to achieve a frame rate of more than 400 images per second. These algorithms were implemented in a simple and cost-effective manner with a single field-programmable gate array (FPGA) and software programs written in C++. The operating speed of the back-end system was investigated by recording the time required for transferring an image to a personal computer. Experimental results showed that the back-end system is capable of producing 433 images per second. To evaluate the imaging performance of the back-end system, a complete imaging system was built. This imaging system, which consisted of a recently reported high-speed mechanical sector scanner assembled with the back-end system, was tested by imaging a wire phantom, a pig eye (in vitro), and a mouse heart (in vivo). It was shown that this system is capable of providing high spatial resolution images with fast temporal resolution.

Low-Cost, High-Speed Back-End Processing System for High-Frequency Ultrasound B-Mode Imaging

PubMed Central

Chang, Jin Ho; Sun, Lei; Yen, Jesse T.; Shung, K. Kirk

2009-01-01

For real-time visualization of the mouse heart (6 to 13 beats per second), a back-end processing system involving high-speed signal processing functions to form and display images has been developed. This back-end system was designed with new signal processing algorithms to achieve a frame rate of more than 400 images per second. These algorithms were implemented in a simple and cost-effective manner with a single field-programmable gate array (FPGA) and software programs written in C++. The operating speed of the back-end system was investigated by recording the time required for transferring an image to a personal computer. Experimental results showed that the back-end system is capable of producing 433 images per second. To evaluate the imaging performance of the back-end system, a complete imaging system was built. This imaging system, which consisted of a recently reported high-speed mechanical sector scanner assembled with the back-end system, was tested by imaging a wire phantom, a pig eye (in vitro), and a mouse heart (in vivo). It was shown that this system is capable of providing high spatial resolution images with fast temporal resolution. PMID:19574160

Review of fluorescence guided surgery systems: identification of key performance capabilities beyond indocyanine green imaging

PubMed Central

DSouza, Alisha V.; Lin, Huiyun; Henderson, Eric R.; Samkoe, Kimberley S.; Pogue, Brian W.

2016-01-01

Abstract. There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here. PMID:27533438

Review of fluorescence guided surgery systems: identification of key performance capabilities beyond indocyanine green imaging

NASA Astrophysics Data System (ADS)

DSouza, Alisha V.; Lin, Huiyun; Henderson, Eric R.; Samkoe, Kimberley S.; Pogue, Brian W.

2016-08-01

There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here.

An airborne thematic thermal infrared and electro-optical imaging system

NASA Astrophysics Data System (ADS)

Sun, Xiuhong; Shu, Peter

2011-08-01

This paper describes an advanced Airborne Thematic Thermal InfraRed and Electro-Optical Imaging System (ATTIREOIS) and its potential applications. ATTIREOIS sensor payload consists of two sets of advanced Focal Plane Arrays (FPAs) - a broadband Thermal InfraRed Sensor (TIRS) and a four (4) band Multispectral Electro-Optical Sensor (MEOS) to approximate Landsat ETM+ bands 1,2,3,4, and 6, and LDCM bands 2,3,4,5, and 10+11. The airborne TIRS is 3-axis stabilized payload capable of providing 3D photogrammetric images with a 1,850 pixel swathwidth via pushbroom operation. MEOS has a total of 116 million simultaneous sensor counts capable of providing 3 cm spatial resolution multispectral orthophotos for continuous airborne mapping. ATTIREOIS is a complete standalone and easy-to-use portable imaging instrument for light aerial vehicle deployment. Its miniaturized backend data system operates all ATTIREOIS imaging sensor components, an INS/GPS, and an e-Gimbal™ Control Electronic Unit (ECU) with a data throughput of 300 Megabytes/sec. The backend provides advanced onboard processing, performing autonomous raw sensor imagery development, TIRS image track-recovery reconstruction, LWIR/VNIR multi-band co-registration, and photogrammetric image processing. With geometric optics and boresight calibrations, the ATTIREOIS data products are directly georeferenced with an accuracy of approximately one meter. A prototype ATTIREOIS has been configured. Its sample LWIR/EO image data will be presented. Potential applications of ATTIREOIS include: 1) Providing timely and cost-effective, precisely and directly georeferenced surface emissive and solar reflective LWIR/VNIR multispectral images via a private Google Earth Globe to enhance NASA's Earth science research capabilities; and 2) Underflight satellites to support satellite measurement calibration and validation observations.