Note: This page contains sample records for the topic patients expanding image from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Expanding Perspectives for Comprehending Visual Images in Multimodal Texts  

ERIC Educational Resources Information Center

The texts that adolescents encounter today are often multimodal, meaning they incorporate a variety of modes, including visual images, hypertext, and graphic design elements along with written text. Expanding the perspectives readers use to make sense of the multimodal texts is an important aspect of comprehension instruction. Moving beyond the…

Serafini, Frank

2011-01-01

2

Expandable endoprosthesis reconstruction in skeletally immature patients with tumors.  

PubMed

Between September 1984 and January 1996, 32 expandable endoprostheses were used for limb reconstruction after resection of malignant bone tumors in patients who were skeletally immature. The 20 boys and 12 girls ranged in age from 3 to 15 years (mean, 9.7 years). One patient had a Stage IIA tumor, 22 patients had Stage IIB tumors, and seven patients had Stage III tumors according to the classification of the Musculoskeletal Tumor Society. There also were two patients with parosteal osteosarcomas. The histologic diagnosis was osteosarcoma in 23 patients and Ewing's sarcoma in nine. All patients except the patients with parosteal osteosarcoma received standard neoadjuvant therapy. Twenty-two Lewis Expandable Adjustable Prostheses, four modular Wright Medical prostheses, four modular Howmedica prostheses, and two Techmedica expandable prostheses were used. Thirteen patients died, two have no evidence of disease, and 17 are continuously disease free. Sixteen of 32 patients (50%) have not had an expansion procedure because of early death in 10 and early amputation in three. Three patients are waiting to undergo an expansion procedure. Sixteen of the 32 patients (50%) have undergone 32 expansion procedures, to a maximum of 9 cm, without any infection. To maintain range of motion before the expansion procedure, a complete resection of the pseudocapsule was done routinely. Fourteen of the 32 patients did not have complications. Eighteen of the 32 patients had 27 complications. All Lewis Expandable Adjustable Prosthesis endoprostheses and the two nonmodular Techmedica prostheses were associated with a large amount of titanium debris. The children's functional results were similar to the results reported for adults with an average Musculoskeletal Tumor Society rating of good to excellent at the knee, fair to good at the hip, and fair about the shoulder. Rehabilitation of the knee in very young patients (5-8 years) remains problematic and careful selection of patient and family is necessary. The Lewis Expandable Adjustable Prosthesis probably should be reserved for very young patients (5-8 years) and modular systems should be used for large preadolescent and adolescent children. PMID:10810462

Eckardt, J J; Kabo, J M; Kelley, C M; Ward, W G; Asavamongkolkul, A; Wirganowicz, P Z; Yang, R S; Eilber, F R

2000-04-01

3

Expanded beam non-imaging fiber optic connector  

DOEpatents

There is disclosed an expanded beam fiber to fiber connector, based on non-imaging optic principles for coupling light beams from one optical fiber to another. The system consists of two identical connector parts, referred to herein as a collimating part and a concentrating part, each having a preferred partially curved reflective boundary surface for minimizing power loss and surrounding either a hollow space or a space filled with a uniform transparent medium. In one embodiment the boundary is metallic while in a second embodiment the boundary is in the form of an interface allowing total internal reflection. In both the hollow and filled case a lens may be located at the expanded end of both the collimator part and the concentrator part forming the connector. The connector is preferably located in a housing in order to protect and preserve the mechanical stability of the coupler. 13 figs.

Jannson, T.; Jannson, J.; Yeung, P.

1990-02-06

4

Expanded beam non-imaging fiber optic connector  

DOEpatents

There is disclosed an expanded beam fiber to fiber connector, based on non-imaging optic principles for coupling light beams from one optical fiber to another. The system consists of two identical connector parts, referred to herein as a collimating part and a concentrating part, each having a preferred partially curved reflective boundary surface for minimizing power loss and surrounding either a hollow space or a space filled with a uniform transparent medium. In one embodiment the boundary is metallic while in a second embodiment the boundary is in the form of an interface allowing total internal reflection. In both the hollow and filled case a lens may be located at the expanded end of both the collimater part and the concentrator part forming the connector. The connector is preferably located in a housing in order to protect and preserve the mechanical stability of the coupler.

Jannson, Tommasz (Redondo Beach, CA); Jannson, Joanna (Redondo Beach, CA); Yeung, Peter (Redondo Beach, CA)

1990-01-01

5

Thinking the phenomenon of image through the poetics of contemporary expanded painting  

Microsoft Academic Search

The history of the painted image has involved various metamorphoses from cave, to architecture, to easel and most recently the radical hybridisation of expanded multimedia forms. Through each age the shedding of one aspect of the image; ritual, spirituality, portability, has resulted in a shift from sacred static images towards profane ephemeral events. This transformation has intensified over the last

Mark Titmarsh

2012-01-01

6

Collision judgment when viewing minified images through a HMD visual field expander  

NASA Astrophysics Data System (ADS)

Purpose: Patients with tunnel vision have great difficulties in mobility. We have developed an augmented vision head mounted device, which can provide patients 5x expanded field by superimposing minified edge images of a wider field captured by a miniature video camera over the natural view seen through the display. In the minified display, objects appear closer to the heading direction than they really are. This might cause users to overestimate collision risks, and therefore to perform unnecessary obstacle-avoidance maneuvers. A study was conducted in a virtual environment to test the impact of minified view on collision judgment. Methods: Simulated scenes were presented to subjects as if they were walking in a shopping mall corridor. Subjects reported whether they would make any contact with stationary obstacles that appeared at variable distances from their walking path. Perceived safe passing distance (PSPD) was calculated by finding the transition point from reports of yes to no. Decision uncertainty was quantified by the sharpness of the transition. Collision envelope (CE) size was calculated by summing up PSPD for left and right sides. Ten normally sighted subjects were tested (1) when not using the device and with one eye patched, and (2) when the see-through view of device was blocked and only minified images were visible. Results: The use of the 5x minification device caused only an 18% increase of CE (13cm, p=0.048). Significant impact of the device on judgment uncertainty was not found (p=0.089). Conclusion: Minification had only a small impact on collision judgment. This supports the use of such a minifying device as an effective field expander for patients with tunnel vision.

Luo, Gang; Lichtenstein, Lee; Peli, Eli

2007-02-01

7

Structural brain network imaging shows expanding disconnection of the motor system in amyotrophic lateral sclerosis.  

PubMed

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease, which primarily targets the motor system. The structural integrity of the motor network and the way it is embedded in the overall brain network is essential for motor functioning. We studied the longitudinal effects of ALS on the brain network using diffusion tensor imaging and questioned whether over time an increasing number of connections become involved or whether there is progressive impairment of a limited number of connections. The brain network was reconstructed based on "whole brain" diffusion tensor imaging data. We examined: (1) network integrity in 24 patients with ALS at baseline (T = 1) and at a more advanced stage of the disease (T = 2; interval 5.5 months) compared with a group of healthy controls and (2) progressive brain network impairment comparing patients at two time-points in a paired-analysis. These analyses demonstrated an expanding subnetwork of affected brain connections over time with a central role for the primary motor regions (P-values T = 1 0.003; T = 2 0.001). Loss of structural connectivity mainly propagated to frontal and parietal brain regions at T = 2 compared with T = 1. No progressive impairment of the initially affected (motor) connections could be detected. The main finding of this study is an increasing loss of network structure in patients with ALS. In contrast to the theory of ALS solely affecting a fixed set of primary motor connections, our findings show that the network of impaired connectivity is expanding over time. These results are in support of disease spread along structural brain connections. Hum Brain Mapp 35:1351-1361, 2014. © 2013 Wiley-Periodicals, Inc. PMID:23450820

Verstraete, Esther; Veldink, Jan H; van den Berg, Leonard H; van den Heuvel, Martijn P

2014-04-01

8

Imaging Stroke Patients with Unclear Onset Times  

PubMed Central

Despite significant progress in stroke prevention and acute treatment, stroke remains a leading cause of death and adult morbidity worldwide. By defining “stroke symptom onset” in the most conservative manner, namely the time the patient was last known to be well, many patients whose onsets are unwitnessed are automatically ineligible for thrombolytic therapy even if their true time of onset would make them eligible. Many groups are trying to determine if advanced brain imaging can serve as a substitute “witness” to estimate stroke onset and duration in those patients who do not have a human witness. We review and compare some of these imaging-based approaches to thrombolysis eligbility, which if successful, can potentially expand the use of thrombolytic therapy to a broader stroke patient population.

Wu, Ona; Schwamm, Lee H.; Sorensen, A. Gregory

2011-01-01

9

Expanding Imaging Platform Functionality for Microfluidic Applications (Brandeis\\/National Science Foundation)  

Microsoft Academic Search

Microfluidics promises solutions to problems ranging from genome sequencing to point-of-care diagnostics. The Microfluidics Laboratory at Brandeis is studying a number of applications including protein crystallization and chemical oscillators. Under a MRSEC grant from the National Science Foundation, Brandeis is expanding user facilities for microfluidics research. Last year, the Olin SCOPE team designed an automated microscope platform capable of imaging

Julie Baca; Spencer Backus; Ashley Banks; Katherine Elliot; Heena Mutha; Matthew Ritter; Emanuel Towns

2010-01-01

10

Autosomal recessive spastic ataxia of Charlevoix Saguenay (ARSACS): expanding the genetic, clinical and imaging spectrum  

PubMed Central

Background Mutations in SACS, leading to autosomal-recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), have been identified as a frequent cause of recessive early-onset ataxia around the world. Here we aimed to enlarge the spectrum of SACS mutations outside Quebec, to establish the pathogenicity of novel variants, and to expand the clinical and imaging phenotype. Methods Sequencing of SACS in 22 patients with unexplained early-onset ataxia, assessment of novel SACS variants in 3.500 European control chromosomes and extensive phenotypic investigations of all SACS carriers. Results We identified 11 index patients harbouring 17 novel SACS variants. 9/11 patients harboured two variants of at least probable pathogenicity which were not observed in controls and, in case of missense mutations, were located in highly conserved domains. These 9 patients accounted for at least 11% (9/83) in our series of unexplained early onset ataxia subjects. While most patients (7/9) showed the classical ARSACS triad, the presenting phenotype reached from pure neuropathy (leading to the initial diagnosis of Charcot-Marie-Tooth disease) in one subject to the absence of any signs of neuropathy in another. In contrast to its name “spastic ataxia”, neither spasticity (absent in 2/9=22%) nor extensor plantar response (absent in 3/9=33%) nor cerebellar ataxia (absent in 1/9=11%) were obligate features. Autonomic features included urine urge incontinence and erectile dysfunction. Apart from the well-established MRI finding of pontine hypointensities, all patients (100%) showed hyperintensities of the lateral pons merging into the (thickened) middle cerebellar peduncles. In addition, 63% exhibited bilateral parietal cerebral atrophy, and 63% a short circumscribed thinning of the posterior midbody of the corpus callosum. In 2 further patients with differences in important clinical features, VUS class 3 variants (c.1373C>T [p.Thr458Ile] and c.2983 G>T [p.Val995Phe]) were identified. These variants were, however, also observed in controls, thus questioning their pathogenic relevance. Conclusions We here demonstrate that each feature of the classical ARSACS triad (cerebellar ataxia, spasticity and peripheral neuropathy) might be missing in ARSACS. Nevertheless, characteristic MRI features – which also extend to supratentorial regions and involve the cerebral cortex – will help to establish the diagnosis in most cases.

2013-01-01

11

Preferred plasma volume expanders for critically ill patients: results of an international survey  

Microsoft Academic Search

Objective: Criteria for plasma volume expander selection in critically ill patients remain contro- versial. This study evaluated prefer- ences of intensivists regarding plas- ma volume expanders. Design: In- ternational survey using a 75-item questionnaire. Participants and setting: All members of the European and French Societies of Intensive Care Medicine (n=2,415 in 1,610 adult ICUs in Europe and elsewhere) were invited

Frédérique Schortgen; Nicolas Deye; Laurent Brochard

2004-01-01

12

Expanding Mental Health Services to Older High-Utilizing HMO Patients: A Pilot Study  

Microsoft Academic Search

Background: Expanded mental health benefits were offered to older HMO patients who were high medical utilizers. Outcomes of interest were use of services, subjective well-being, and psychopathology. Methods: Sixty-nine (25 male, 44 female) patients age 55 or above seeking frequent outpatient medical care completed the SF-36 health survey and the revised Symptom Check List (SCL-90-R). Patients were assigned to usual

Leonard J. Haas; David C. Spendlove; Michael P. Silver

2001-01-01

13

Expanded Dempster-Shafer reasoning technique for image feature integration and object recognition  

NASA Astrophysics Data System (ADS)

Integration of information from multiple sources has been one of the key steps to the success of general vision systems. It is also an essential problem to the development of color image understanding algorithms that make full use of the multichannel color data for object recognition. This paper presents a feature integration system characterized by a hybrid combination of a statistic-based reasoning technique and a symbolic logic-based inference method. A competitive evidence enhancement scheme is used in the process to fuse information from multiple sources. The scheme expands the Dempster-Shafer's function of combination and improves the reliability of the object recognition. When applied to integrate the object features extracted from the multiple spectra of the color images, the system alleviates the drawback of traditional Baysian classification system.

Zhu, Quiming; Huang, Yinghua; Payne, Matt G.

1992-12-01

14

Neurotrophic factor expression in expandable cell populations from brain samples in living patients with Parkinson's disease.  

PubMed

Cell-based therapies offer promise for patients with Parkinson's disease (PD); however, durable and effective transplantation substrates need to be defined. This study characterized the feasibility and growth properties of primary cultures established from small-volume brain biopsies taken during deep brain stimulation (DBS) surgery in patients with PD. The lineage and expression of neurotrophic factors with known beneficial actions in PD-affected brain circuitry were also evaluated. Nineteen patients with PD undergoing DBS surgery consented to brain biopsies prior to electrode implantation. Cultures from these samples exhibited exponential and plateau phases of growth and were readily expanded throughout multiple passages. There was robust expression of progenitor markers and the unexpected colocalization of neural and mesenchymal proteins. The oligodendrocyte transcription factor, Olig1, and the myelin-specific sphingolipid, galactocerebroside, were coexpressed with each of glial-derived neurotrophic factor, brain-derived neurotrophic factor, and cerebral dopamine neurotrophic factor. Fluorescence-activated cell sorting demonstrated homogeneous expression of both nestin and Olig1 throughout the expanded cultures. Cells remained viable after a year in cryostorage. These findings confirm the feasibility of small brain biopsies as an expandable source of autologous cell substrate in living patients and demonstrate the complex phenotype of these cells, with implications for therapeutic application in PD and other neurological diseases. PMID:23825231

Xu, Hu; Belkacemi, Louiza; Jog, Mandar; Parrent, Andrew; Hebb, Matthew O

2013-10-01

15

Expanded access and patient assistance programs for other experimental drugs from their manufacturers.  

PubMed

The cost of prescription drugs for AIDS treatment is high, and many people have inadequate insurance to cover them. Several pharmaceutical companies have set up hotlines and patient assistance programs to help people get the drugs. Most programs require a physician to do the actual enrollment of patients into the program. Eligibility requirements vary. Each State also has an AIDS Drug Assistance Program (ADAP). A number of expanded access programs and other assistance programs are detailed, including contact numbers for specific enrollment information. PMID:11364445

1997-01-01

16

Expanded Access  

MedlinePLUS

... appropriate. 4. Chemistry, Manufacturing, and Controls Information and Pharmacology and Toxicology Information including a description of the ... requesting expanded access. Some companies establish a lottery system to determine which patients will have treatment access. ...

17

Structure of native and expanded sobemoviruses by electron cryo-microscopy and image reconstruction.  

PubMed

Rice yellow mottle virus (RYMV) and southern bean mosaic virus, cowpea strain (SCPMV) are members of the Sobemovirus genus of RNA-containing viruses. We used electron cryo-microscopy (cryo-EM) and icosahedral image analysis to examine the native structures of these two viruses at 25 A resolution. Both viruses have a single tightly packed capsid layer with 180 subunits assembled on a T=3 icosahedral lattice. Distinctive crown-like pentamers emanate from the 12 5-fold axes of symmetry. The exterior face of SCPMV displays deep valleys along the 2-fold axes and protrusions at the quasi-3-fold axes. While having a similar topography, the surface of RYMV is comparatively smooth. Two concentric shells of density reside beneath the capsid layer of RYMV and SCPMV, which we interpret as ordered regions of genomic RNA. In the presence of divalent cations, SCPMV particles swell and fracture, whereas the expanded form of RYMV is stable. We previously proposed that the cell-to-cell movement of RYMV in xylem involves chelation of Ca(2+) from pit membranes of infected cells, thereby stabilizing the capsid shells and allowing a pathway for spread of RYMV through destabilized membranes. In the context of this model, we propose that the expanded form of RYMV is an intermediate in the in vivo assembly of virions. PMID:11023786

Opalka, N; Tihova, M; Brugidou, C; Kumar, A; Beachy, R N; Fauquet, C M; Yeager, M

2000-10-20

18

Malignant biliary obstruction: treatment with expandable metallic stents--follow-up of 50 consecutive patients.  

PubMed

A consecutive series of 50 patients with malignant biliary obstruction were treated by means of palliative drainage with a metallic expandable stent. Stent placement was successful in all patients. The patients were followed up prospectively at 2-month intervals over a period of 9-22 months. Forty-one patients (82%) died; nine (18%) are still living. The overall patency and survival rates for the 50 patients were 5.8 months and 7.5 months, respectively. The 30-day mortality rate was 8% (n = 4), the minor complication rate was 18% (n = 9), and the major complication rate was 8% (n = 4). One patient (2%) had intrahepatic arterial bleeding that required embolization, one (2%) had a right subphrenic abscess, and two patients (4%) had transient septic events. Stent occlusion requiring a second intervention occurred in 24% of patients (n = 12). Excellent palliation was achieved in most patients. No stent migration occurred. No great clinical advantages in prolonged patency compared with those of other published series involving the use of plastic stents were demonstrated. Ease of placement and versatility may offset the high cost of the stent. PMID:1371362

Gordon, R L; Ring, E J; LaBerge, J M; Doherty, M M

1992-03-01

19

A micromechanical expanding coil mechanism for in vivo magnetic resonance imaging  

NASA Astrophysics Data System (ADS)

A mechanism for an expanding coil designed for use for in vivo magnetic resonance imaging is demonstrated. The mechanism has a small (1 mm) cross-sectional width, and may therefore be passed through a tubular orifice such as the endoscope channel used for accessing a bile duct. Once in place, the coil may be deformed by controlled in-plane buckling and fixed in this state by a rack-and-tooth latch. The latch may be released to return the mechanism to its original state for withdrawal. A simple analytic model of the device is developed using Euler bending theory. Prototypes are fabricated in bonded silicon-on-insulator material by deep reactive ion etching and undercut. Expansion and latching are demonstrated, and performance characteristics are found to be in good agreement with the theoretical models. A lateral expansion of 1 mm was routinely achieved on either side of a device with an initial width of 1 mm (corresponding to a three-fold expansion) using an axial compression of 400 µm.

Ichiki, M.; Syms, R. R. A.; Young, I. R.

2005-04-01

20

Development of a bent Laue beam-expanding double-crystal monochromator for biomedical X-ray imaging  

PubMed Central

The Biomedical Imaging and Therapy (BMIT) beamline at the Canadian Light Source has produced some excellent biological imaging data. However, the disadvantage of a small vertical beam limits its usability in some applications. Micro-computed tomography (micro-CT) imaging requires multiple scans to produce a full projection, and certain dynamic imaging experiments are not possible. A larger vertical beam is desirable. It was cost-prohibitive to build a longer beamline that would have produced a large vertical beam. Instead, it was proposed to develop a beam expander that would create a beam appearing to originate at a source much farther away. This was accomplished using a bent Laue double-crystal monochromator in a non-dispersive divergent geometry. The design and implementation of this beam expander is presented along with results from the micro-CT and dynamic imaging tests conducted with this beam. Flux (photons per unit area per unit time) has been measured and found to be comparable with the existing flat Bragg double-crystal monochromator in use at BMIT. This increase in overall photon count is due to the enhanced bandwidth of the bent Laue configuration. Whilst the expanded beam quality is suitable for dynamic imaging and micro-CT, further work is required to improve its phase and coherence properties.

Martinson, Mercedes; Samadi, Nazanin; Belev, George; Bassey, Bassey; Lewis, Rob; Aulakh, Gurpreet; Chapman, Dean

2014-01-01

21

Transapical Aortic Valve Replacement under Real-time Magnetic Resonance Imaging Guidance: Experimental Results with Balloon-Expandable and Self-Expanding Stents  

PubMed Central

Objective Aortic valves have been implanted on self-expanding (SE) and balloon-expandable (BE) stents minimally invasively. We have demonstrated the advantages of transapical aortic valve implantation (tAVI) under real-time magnetic resonance imaging (rtMRI) guidance. Whether there are different advantages to SE or BE stents is unknown. We report rtMRI guided tAVI in a porcine model using both SE and BE stents, and compare the differences between the stents. Methods Twenty-two Yucatan pigs (45-57kgs.) underwent tAVI. Commercially available stentless bioprostheses (21-25mm) were mounted on either BE platinum-iridium stents or SE nitinol stents. rtMRI guidance was employed as the intraoperative imaging. Markers on both types of stents were used to enhance the visualization in rtMRI. Pigs were allowed to survive and had follow-up MRI scans and echocardiography at 1, 3 and 6 months postoperatively. Results rtMRI provided excellent visualization of the aortic valve implantation mounted on both stent types. The implantation times were shorter with the SE stents (60±14 seconds) than BE (74±18s), (p=0.027). Total procedure time was 31 and 37 minutes respectively (p=0.12). It was considerably easier to manipulate the SE stent during deployment without hemodynamic compromise. This was not always the case with the BE stent and its placement occasionally resulted in coronary obstruction and death. Long-term results demonstrated stability of the implants with preservation of myocardial perfusion and function over time for both stents. Conclusions SE stents were easier to position and deploy thus leading to fewer complications during tAVI. Future optimization of SE stent design should improve clinical results.

Horvath, Keith A.; Mazilu, Dumitru; Kocaturk, Ozgur; Li, Ming

2010-01-01

22

Expanding the use of patient reports about patient-centered care.  

PubMed

In an informative article on the assessment of patient care experiences, Zimlichman, Rozenblum, and Millenson describe the evolving use of surveys that elicit patient reports about medical care experiences in Israel, a trend that parallels developments in the U.S. This commentary summarizes some of experiences in the U.S. that might inform the development of more consistent and extensive strategies for assessing and promoting patient-centered care in Israel.More comprehensive patient experience surveys, the results of which would be publicly available, as Zimlichman and colleagues advocate, would facilitate quality improvements, especially if users are provided with support for the use and interpretation of the data. Developing more efficient survey methods will facilitate the broader use of such surveys, although it is important to use methods that yield results that are as representative of the target population as possible and to account for survey mode effects when data are reported. Although the surveys need to be appropriate for the Israeli context, the use of standard questions used in other countries would facilitate comparisons that could help to identify best practices that can be adopted in different settings. Those who work on assessing patient-centered care in the U.S. look forward to learning from the work of their Israeli colleagues.This is a commentary on http://www.ijhpr.org/content/2/1/35/. PMID:24044702

Cleary, Paul D

2013-01-01

23

Aneurysmal Lesions of Patients with Abdominal Aortic Aneurysm Contain Clonally Expanded T Cells  

PubMed Central

Abdominal aortic aneurysm (AAA) is a common disease with often life-threatening consequences. This vascular disorder is responsible for 1–2% of all deaths in men aged 65 years or older. Autoimmunity may be responsible for the pathogenesis of AAA. Although it is well documented that infiltrating T cells are essentially always present in AAA lesions, little is known about their role in the initiation and/or progression of the disease. To determine whether T cells infiltrating AAA lesions contain clonally expanded populations of T cells, we amplified ?-chain TCR transcripts by the nonpalindromic adaptor–PCR/V?-specific PCR and/or V?-specific PCR, followed by cloning and sequencing. We report in this article that aortic abdominal aneurysmal lesions from 8 of 10 patients with AAA contained oligoclonal populations of T cells. Multiple identical copies of ?-chain TCR transcripts were identified in these patients. These clonal expansions are statistically significant. These results demonstrate that ?? TCR+ T lymphocytes infiltrating aneurysmal lesions of patients with AAA have undergone proliferation and clonal expansion in vivo at the site of the aneurysmal lesion, in response to unidentified self- or nonself Ags. This evidence supports the hypothesis that AAA is a specific Ag–driven T cell disease.

Lu, Song; White, John V.; Lin, Wan Lu; Zhang, Xiaoying; Solomides, Charalambos; Evans, Kyle; Ntaoula, Nectaria; Nwaneshiudu, Ifeyinwa; Gaughan, John; Monos, Dimitri S.; Oleszak, Emilia L.

2014-01-01

24

Aneurysmal lesions of patients with abdominal aortic aneurysm contain clonally expanded T cells.  

PubMed

Abdominal aortic aneurysm (AAA) is a common disease with often life-threatening consequences. This vascular disorder is responsible for 1-2% of all deaths in men aged 65 years or older. Autoimmunity may be responsible for the pathogenesis of AAA. Although it is well documented that infiltrating T cells are essentially always present in AAA lesions, little is known about their role in the initiation and/or progression of the disease. To determine whether T cells infiltrating AAA lesions contain clonally expanded populations of T cells, we amplified ?-chain TCR transcripts by the nonpalindromic adaptor-PCR/V?-specific PCR and/or V?-specific PCR, followed by cloning and sequencing. We report in this article that aortic abdominal aneurysmal lesions from 8 of 10 patients with AAA contained oligoclonal populations of T cells. Multiple identical copies of ?-chain TCR transcripts were identified in these patients. These clonal expansions are statistically significant. These results demonstrate that ?? TCR(+) T lymphocytes infiltrating aneurysmal lesions of patients with AAA have undergone proliferation and clonal expansion in vivo at the site of the aneurysmal lesion, in response to unidentified self- or nonself Ags. This evidence supports the hypothesis that AAA is a specific Ag-driven T cell disease. PMID:24752442

Lu, Song; White, John V; Lin, Wan Lu; Zhang, Xiaoying; Solomides, Charalambos; Evans, Kyle; Ntaoula, Nectaria; Nwaneshiudu, Ifeyinwa; Gaughan, John; Monos, Dimitri S; Oleszak, Emilia L; Platsoucas, Chris D

2014-05-15

25

Self-expandable metallic stents for palliation of patients with malignant gastric outlet obstruction caused by stomach cancer  

PubMed Central

AIM: To ascertain clinical outcome and complications of self-expandable metal stents for endoscopic palliation of patients with malignant obstruction of the gastrointestinal (GI) tract. METHODS: A retrospective review was performed throughout August 2000 to June 2005 of 53 patients with gastric outlet obstruction caused by stomach cancer. All patients had symptomatic obstruction including nausea, vomiting, and decreased oral intake. All received self-expandable metallic stents. RESULTS: Stent implantation was successful in all 53 (100%) patients. Relief of obstructive symptoms was achieved in 43 (81.1%) patients. No immediate stent-related complications were noted. Seventeen patients had recurrent obstruction (tumor ingrowth in 14 patients, tumor overgrowth in 1 patient, and partial distal stent migration in 2 patients). The mean survival was 145 d. Median stent patency time was 187 d. CONCLUSION: Endoscopic placement of self-expandable metallic stents is a safe and effective treatment for the palliation of patients with inoperable malignant gastric outlet obstruction caused by stomach cancer.

Kim, Tae Oh; Kang, Dae Hwan; Kim, Gwang Ha; Heo, Jeong; Song, Geun Am; Cho, Mong; Kim, Dong Heon; Sim, Mun Sup

2007-01-01

26

Thallium-201 stress imaging in hypertensive patients  

SciTech Connect

To assess the potential effect of hypertension on the results of thallium-201 stress imaging in patients with chest pain, 272 thallium-201 stress tests performed in 133 hypertensive patients and 139 normotensive patients over a 1-year period were reviewed. Normotensive and hypertensive patients were similar in age, gender distribution, prevalence of cardiac risk factors (tobacco smoking, hyperlipidemia, and diabetes mellitus), medications, and clinical symptoms of coronary disease. Electrocardiographic criteria for left ventricular hypertrophy were present in 16 hypertensive patients. Stepwise probability analysis was used to determine the likelihood of coronary artery disease for each patient. In patients with mid to high likelihood of coronary disease (greater than 25% probability), abnormal thallium-201 stress images were present in 54 of 60 (90%) hypertensive patients compared with 51 of 64 (80%) normotensive patients. However, in 73 patients with a low likelihood of coronary disease (less than or equal to 25% probability), abnormal thallium-201 stress images were present in 21 patients (29%) of the hypertensive group compared with only 5 of 75 (7%) of the normotensive patients (p less than 0.001). These findings suggest that in patients with a mid to high likelihood of coronary artery disease, coexistent hypertension does not affect the results of thallium-201 exercise stress testing. However, in patients with a low likelihood of coronary artery disease, abnormal thallium-201 stress images are obtained more frequently in hypertensive patients than in normotensive patients.

Schulman, D.S.; Francis, C.K.; Black, H.R.; Wackers, F.J.

1987-07-01

27

Technical aspects of unilateral dual kidney transplantation from expanded criteria donors: experience of 100 patients.  

PubMed

One option for using organs from donors with a suboptimal nephron mass, e.g. expanded criteria donors (ECD) kidneys, is dual kidney transplantation (DKT). In adult recipients, DKT can be carried out by several techniques, but the unilateral placement of both kidneys (UDKT) offers the advantages of single surgical access and shorter operating time. One hundred UDKT were performed using kidneys from ECD donors with a mean age of 72 years (Group 1). The technique consists of transplanting both kidneys extraperitoneally in the same iliac fossa. The results were compared with a cohort of single kidney transplants (SKT) performed with the same selection criteria in the same study period (Group 2, n = 73). Ninety-five percent of UDKTs were positioned in the right iliac fossa, lengthening the right renal vein with an inferior vena cava patch. In 69% of cases, all anastomoses were to the external iliac vessels end-to-side. Surgical complications were comparable in both groups. At 3-year follow-up, patient and graft survival rates were 95.6 and 90.9% in Group 1, respectively. UDKT can be carried out with comparable surgical complication rates as SKT, leaving the contralateral iliac fossa untouched and giving elderly recipients a better chance of receiving a transplant, with optimal results up to 3-years follow-up. PMID:20636454

Ekser, B; Furian, L; Broggiato, A; Silvestre, C; Pierobon, E S; Baldan, N; Rigotti, P

2010-09-01

28

Nanodiamond molecular imaging with enhanced contrast and expanded field of view  

NASA Astrophysics Data System (ADS)

Nanodiamond imaging is a new molecular imaging modality that takes advantage of nitrogen-vacancy (NV) centers in nanodiamonds to image a distribution of nanodiamonds with high sensitivity and high spatial resolution. Since nanodiamonds are nontoxic and are easily conjugated to biomolecules, nanodiamond imaging can potentially elicit physiological information from within a living organism. The position of the nanodiamonds is measured using optically detected electron spin resonance of the NVs. In a previous paper, we described a proof-of-principle nanodiamond imaging system with the ability to image in two dimensions over a 1×1 cm field of view and demonstrated imaging within scattering tissue. Here, we describe a second-generation nanodiamond imaging system with a field of view of 30×200 mm, and with three-dimensional imaging potential. The new system has a comparable spatial resolution of 1.2 mm FWHM and a sensitivity (in terms of the concentration of carbon atoms in a voxel) of 1.6 Hz, a 3-dB improvement relative to the old system. We show that imaging at 2.872 GHz versus imaging at 2.869 GHz offers a 1.73× improvement in sensitivity with only a 20% decrease in resolution and motivate this by describing the observed lineshape starting from the NV spin Hamiltonian.

Hegyi, Alex; Yablonovitch, Eli

2014-01-01

29

Nanodiamond molecular imaging with enhanced contrast and expanded field of view.  

PubMed

Nanodiamond imaging is a new molecular imaging modality that takes advantage of nitrogen-vacancy (NV) centers in nanodiamonds to image a distribution of nanodiamonds with high sensitivity and high spatial resolution. Since nanodiamonds are nontoxic and are easily conjugated to biomolecules, nanodiamond imaging can potentially elicit physiological information from within a living organism. The position of the nanodiamonds is measured using optically detected electron spin resonance of the NVs. In a previous paper, we described a proof-of-principle nanodiamond imaging system with the ability to image in two dimensions over a 1×1??cm field of view and demonstrated imaging within scattering tissue. Here, we describe a second-generation nanodiamond imaging system with a field of view of 30×200??mm, and with three-dimensional imaging potential. The new system has a comparable spatial resolution of 1.2 mm FWHM and a sensitivity (in terms of the concentration of carbon atoms in a ?mm3? voxel) of 1.6??mM?mm3?Hz-1/2, a 3-dB improvement relative to the old system. We show that imaging at 2.872 GHz versus imaging at 2.869 GHz offers a 1.73× improvement in sensitivity with only a 20% decrease in resolution and motivate this by describing the observed lineshape starting from the NV spin Hamiltonian. PMID:24057337

Hegyi, Alex; Yablonovitch, Eli

2014-01-01

30

Expanded colesevelam administration options with oral suspension formulation for patients with diabetes and hypercholesterolemia.  

PubMed

Introduction: Colesevelam HCl (colesevelam) is a bile acid sequestrant initially approved by the US Food and Drug Administration (FDA) in 2000 as an adjunct to diet and exercise to lower elevated low-density lipoprotein cholesterol (LDL-C) levels in adults with primary lipidemia, as monotherapy, or in combination with a statin. More recently, the drug was approved for use in adults with type 2 diabetes mellitus (T2DM) to improve glycemic control. Thus, colesevelam is currently the only single-agent monotherapy approved by the FDA to lower both LDL-C and glycated hemoglobin (A1c) levels in adults with T2DM and elevated LDL-C. Moreover, the formulation options for colesevelam have also expanded since its original approval. Materials and Methods: A Medline search was conducted to provide evidence to support the efficacy and safety for the use of colesevelam tablets or oral suspension preparations when treating patients with lipidemia, T2DM, or both. No limitations were placed on publication date or any other parameter. Results: Clinical studies have shown that colesevelam is efficacious in lowering LDL-C levels, improving the lipid profile, and improving glycemic control by reducing both A1c and fasting plasma glucose levels in T2DM. Equilibrium and kinetics data show that colesevelam is equivalent in its tablet and oral suspension formulation. Conclusion: Having 2 effective oral routes enhances convenience and improves compliance, both of which contribute to maximal therapeutic outcomes. These compliance benefits are due to the ease and flexibility of preparing the powder in various beverages and the pleasant taste from the inclusion of a low-calorie citrus flavoring. PMID:24918798

Dayer-Berenson, Linda; Finckenor, Mary

2014-05-01

31

Self expanding stents in congenital heart disease.  

PubMed Central

OBJECTIVES--To show potential indications for and clinical use of self expanding stents in patients with congenital heart disease. DESIGN--Descriptive study of selected, non-randomised patients with balloon expandable but persistent stenoses in whom the use of a balloon expandable stent was considered suboptimal or impossible. SETTING--A tertiary referral centre. PATIENTS--10 patients, aged 15 days to 32 years. Six patients after atriopulmonary or cavopulmonary anastomosis, two with pulmonary atresia and multiple aortopulmonary collaterals, one with coarctation of the aorta, and one with congenital pulmonary venous stenosis. RESULTS--Successful, uncomplicated, placement of 10 stents with the desired haemodynamic results, even in tortuous vessels with many stenoses. CONCLUSIONS--Self expanding stents have a role in the treatment of patients with congenital heart disease. They should be considered when a smaller delivery system and flexibility would aid placement, or in the treatment of long or multiple sequential stenoses. Images

Redington, A N; Weil, J; Somerville, J

1994-01-01

32

Efficacy of ex vivo activated and expanded natural killer cells and T lymphocytes for colorectal cancer patients  

PubMed Central

Immune cell-based therapies using natural killer (NK) cells and cytotoxic T cells are under constant scrutiny, with the aim to design an effective and reduced-toxicity therapy, which will benefit patients via improved quality of life and improved prognosis. Four patients with stage IV colon cancer were administered 1, 3, 5 and 6 effector cell intravenous infusions, respectively. Peripheral blood was collected from the patients and the ex vivo activation and expansion of NK and T cells was performed in Good Manufacturing Practice-certified clean rooms for ~12–15 days. Immunophenotypic analysis of the peripheral blood mononuclear cells (PBMCs) and expanded NK and T cells was conducted using flow cytometry and the patients were followed up. On average, 4.8×107 initial PBMCs and 2.7×109 total expanded cells were obtained. The intravenous infusions of the expanded cells were not accompanied by adverse reactions. Improved prognosis, reflected by a considerable decrease in the cancer markers, accompanied by an improved quality of life in the patients were observed. In conclusion, potential strategies are currently under development for the large-scale production of effectors cells; therefore, autologous immune enhancement therapy (AIET) may be considered as a viable approach to cancer treatment.

SUBRAMANI, BASKAR; PULLAI, CHITHRA RAMANATHAN; KRISHNAN, KOHILA; SUGADAN, SHEELA DEVI; DENG, XUEWEN; HIROSHI, TERUNUMA; RATNAVELU, KANANATHAN

2014-01-01

33

Imaging of trauma in the pregnant patient.  

PubMed

The pregnant trauma patient presents an important and challenging encounter for the clinical team and radiologist. In this article, we present several key aspects of the imaging workup of pregnant trauma patients, beginning with a review of the modalities that are used in this setting. Ultrasonography plays an important role in initial evaluation of the fetus but a limited role in evaluation of maternal injuries. Given that conventional radiography and computed tomography are the "workhorse" modalities for evaluation of pregnant trauma patients, radiologists must pay particular attention to radiation dose concerns. Magnetic resonance imaging can be used after the initial evaluation and for follow-up imaging, and safety concerns related to its use in pregnant patients are addressed. At imaging interpretation, radiologists must contend not only with the typical spectrum of injuries that can be seen in any trauma patient but also with pregnancy-specific injuries, such as placental abruption and uterine rupture. Particularly unusual situations, such as a ruptured ectopic pregnancy in a trauma patient, are presented. Although pregnant trauma patients are infrequently encountered, familiarity with imaging findings of injuries in these patients is essential to providing the best care for the mother and fetus. © RSNA, 2014. PMID:24819793

Raptis, Constantine A; Mellnick, Vincent M; Raptis, Demetrios A; Kitchin, Douglas; Fowler, Kathryn J; Lubner, Meghan; Bhalla, Sanjeev; Menias, Christine O

2014-01-01

34

High-resolution Expanded Very Large Array Image of Dimethyl Ether (CH3)2O in Orion-KL  

NASA Astrophysics Data System (ADS)

We report the first subarcsecond (0farcs65 × 0farcs51) image of the dimethyl ether molecule, (CH3)2O, toward the Orion Kleinmann-Low nebula. The observations were carried at 43.4 GHz with the Expanded Very Large Array (EVLA). The distribution of the lower energy transition 61, 5-60, 6, EE (E u = 21 K) mapped in this study is in excellent agreement with the published dimethyl ether emission maps imaged with a lower resolution. The main emission peaks are observed toward the Compact Ridge and Hot Core southwest components, at the northern parts of the Compact Ridge and in an intermediate position between the Compact Ridge and the Hot Core. A notable result is that the distribution of dimethyl ether is very similar to that of another important larger O-bearing species, the methyl formate (HCOOCH3), imaged at a lower resolution. Our study shows that higher spectral resolution (WIDAR correlator) and increased spectral coverage provided by the EVLA offer new possibilities for imaging complex molecular species. The sensitivity improvement and the other EVLA improvements make this instrument well suited for high sensitivity, high angular resolution, and molecular line imaging.

Favre, C.; Wootten, H. A.; Remijan, A. J.; Brouillet, N.; Wilson, T. L.; Despois, D.; Baudry, A.

2011-09-01

35

Skin-sparing mastectomy and immediate tissue expander breast reconstruction in patients with macromastia using the passot breast reduction pattern.  

PubMed

Skin-sparing mastectomy (SSM) with immediate tissue expander reconstruction poses a challenge in the patient with macromastia or excessive ptosis. Skin reduction via the Wise pattern has been described but is associated with high rates of skin necrosis. The study group consisted of 43 women with grade 2 or 3 ptosis who underwent SSM and immediate reconstruction with tissue expanders, using the Passot (horizontal) skin reduction pattern. Age ranged from 31 to 67 years (mean, 51 years). The endpoints measured were time to final expansion, mastectomy skin flap necrosis, infectious complications, and total complications. Thirty reconstructions were bilateral and 13 were unilateral (73 breasts total). Follow-up ranged from 6 to 55 months (mean, 20). Common comorbid conditions included hypertension (n = 16), obesity (n = 22), and smoking (n = 9). The mean body mass index was 30.6 (range, 19.4-58.6). Twenty-one patients underwent chemotherapy; 12 received radiation. The mean initial fill was 196 mL (range, 0-420 mL), and the mean time to final expansion was 84 days (range, 28-225 days). Five patients did not complete the reconstruction, 2 because of cancer recurrence and 3 because of infection. There were 3 cases of mastectomy flap necrosis occurring after tissue expander placement (7%). There were 7 infectious complications (16%). The use of a horizontal breast reduction pattern at the time of expander placement produces consistently good esthetic outcomes and a low rate of skin necrosis, and it should be considered as an option in patients with macromastia or ptosis undergoing SSM and immediate reconstruction. PMID:24835873

Rinker, Brian; Thornton, Brian P

2014-06-01

36

A PILOT IMAGING LINE SURVEY OF RW LMi AND IK Tau USING THE EXPANDED VERY LARGE ARRAY  

SciTech Connect

We report on a pilot imaging line survey (36.0-37.0 GHz, with {approx}1 km s{sup -1} spectral channels) with the Expanded Very Large Array for two asymptotic giant branch stars, RW LMi (= CIT6, which has a carbon-rich circumstellar envelope, CSE) and IK Tau (=NML Tau, with an oxygen-rich CSE). Radio continuum emission consistent with photospheric emission was detected from both stars. From RW LMi we imaged the HC{sub 3}N (J = 4{yields}3) emission. The images show several partial rings of emission; these multiple shells trace the evolution of the CSE from 400 to 1200 years. SiS (J = 2{yields}1) emission was detected from both RW LMi and IK Tau. For both stars the SiS emission is centrally condensed with the peak line emission coincident with the stellar radio continuum emission. In addition, we have detected weak HC{sub 7}N (J = 32{yields}31) emission from RW LMi.

Claussen, M. J.; Sjouwerman, L. O.; Rupen, M. P. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Olofsson, H.; Schoeier, F. L.; Bergman, P. [Onsala Space Observatory, Department of Radio and Space Science, Chalmers University of Technology, 43992 Onsala (Sweden); Knapp, G. R. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2011-09-20

37

Geodetic Imaging: Expanding the Boundaries of Geodesy in the 21st Century  

NASA Astrophysics Data System (ADS)

High resolution (sub-meter) geodetic images covering tens to thousands of square kilometers have extended the boundaries of geodesy into related areas of the earth sciences, such as geomorphology and geodynamics, during the past decade, to archaeological exploration and site mapping during the past few years, and are now poised to transform studies of flora and fauna in the more remote regions of the world. Geodetic images produced from airborne laser scanning (ALS), a.k.a. airborne light detection and ranging (LiDAR) have proven transformative to the modern practice of geomorphology where researchers have used decimeter resolution digital elevation models (DEMs) to determine the spatial frequencies of evenly spaced features in terrain, and developed models and mathematical equations to explain how the terrain evolved to its present state and how it is expected to change in the future (Perron et al., 2009). In geodynamics researchers have used ';before' and ';after' geodetic images of the terrain near earthquakes, such as the 2010 El Mayor-Cucapah Earthquake, to quantify surface displacements and suggest models to explain the observed deformations (Oskin et. al., 2012). In archaeology, the ability of ALS to produce ';bare earth' DEMs of terrain covered with dense vegetation, including even tropical rain forests, has revolutionized the study of archaeology in highly forested areas, finding ancient structures and human modifications of landscapes not discovered by archaeologists working at sites for decades (Chase et al., 2011 & Evans et al., 2013), and finding previously unknown ruins in areas that ground exploration has not been able to penetrate since the arrival of the conquistadors in the new world in the 17th century (Carter et al., 2012). The improved spatial resolution and ability of the third generation ALS units to obtain high resolution bare earth DEMs and canopy models in areas covered in dense forests, brush, and even shallow water (steams, lakes, and coastal waters) is just beginning to attract the attention of researchers studying such plant life as marsh vegetation and sea grasses, and the habitats of animals as diverse as fish, migratory birds, and lions (Vierling et al., 2008). From thousands and thousands of survey markers covering large regions of the earth common to geodesy a half century ago, the focus of some geodesist has changed to billions and billions of points covering landscapes, which are enabling them to redefine and extend the limits of geodesy in the 21st century. References: Carter, W. E. et al., (2012), 'Geodetic Imaging: A New Tool for Mesoamerican Archaeology,' Eos, Trans. American Geophysical Union, Vol. 93, No. 42, pages 413-415. Chase, A. F. et al., (2010) 'Airborne LiDAR, archaeology, and the ancient Maya landscape at Caracol, Belize,' Journal Of Archaeological Science, vol. 38, no. 2, p. 387-398. Evans, D. H. et al., (2013), 'Uncovering archaeological landscapes at Angkor using lidar.' PNAS. Oskin, M. E. et al., (2012), 'Near-Field Deformation from the El Mayor-Cucapah Earthquake Revealed by Differential LIDAR,' Science. Vol. 335 no.6069, pp. 702-705. Perron, J. Taylor, et al (2009), 'Formation of evenly spaced ridges and valleys,' Nature, Vol. 460/23. Vierling, K. T. et al., (2008),'Lidar: shedding new light on habitat characterization and modeling,' Front Ecol Environ 2008, 6(2): 90-98.

Fernandez Diaz, J. C.; Carter, W. E.; Shrestha, R. L.; Glennie, C. L.

2013-12-01

38

Genetically-Encoded Yellow Fluorescent cAMP Indicator with an Expanded Dynamic Range for Dual-Color Imaging  

PubMed Central

Cyclic AMP is a ubiquitous second messenger, which mediates many cellular responses mainly initiated by activation of cell surface receptors. Various Förster resonance energy transfer-based ratiometric cAMP indicators have been created for monitoring the spatial and temporal dynamics of cAMP at the single-cell level. However, single fluorescent protein-based cAMP indicators have been poorly developed, with improvement required for dynamic range and brightness. Based on our previous yellow fluorescent protein-based cAMP indicator, Flamindo, we developed an improved yellow fluorescent cAMP indicator named Flamindo2. Flamindo2 has a 2-fold expanded dynamic range and 8-fold increased brightness compared with Flamindo by optimization of linker peptides in the vicinity of the chromophore. We found that fluorescence intensity of Flamindo2 was decreased to 25% in response to cAMP. Live-cell cAMP imaging of the cytosol and nucleus in COS7 cells using Flamindo2 and nlsFlamindo2, respectively, showed that forskolin elevated cAMP levels in each compartment with different kinetics. Furthermore, dual-color imaging of cAMP and Ca2+ with Flamindo2 and a red fluorescent Ca2+ indicator, R-GECO, showed that cAMP and Ca2+ elevation were induced by noradrenaline in single HeLa cells. Our study shows that Flamindo2, which is feasible for multi-color imaging with other intracellular signaling molecules, is useful and is an alternative tool for live-cell imaging of intracellular cAMP dynamics.

Odaka, Haruki; Arai, Satoshi; Inoue, Takafumi; Kitaguchi, Tetsuya

2014-01-01

39

Spectrum of Di George syndrome in patients with truncus arteriosus: Expanded Di George syndrome  

Microsoft Academic Search

Summary A study of 26 patients with truncus arteriosus showed a high prevalence of facial dysmorphism, aortic arch abnormalities, extracardiac malformations, and significant prenatal risk factors. There was little evidence of parathyroid or thymic abnormalities. However, there was laboratory evidence of immune deficiency, especially T-helper lymphocytes, and clinical evidence of predilection to infection. These findings suggest that patients with truncus

Dorothy J. Radford; Lisa Perkins; Rosa Lachman; Y. H. Thong

1988-01-01

40

Patient Centered Outcomes in Imaging: Quantifying Value  

PubMed Central

The Patient Centered Outcomes Research Institute (PCORI) was created in response to a mandate to conduct comparative effectiveness research in clinical care to inform decision-making. PCORI will be funded by the PCOR Trust Fund, through congressional set-asides, and by Medicare and private health insurers, through a per-beneficiary fee. PCORI is governed by a Board with a broad stakeholder constitution. Key committees set the national agenda for patient-centered outcomes research, the agenda for funding priorities, and communication and dissemination of the evidence with the goal of increasing the rate of implementation of the evidence into policy. In imaging, patient centered outcomes go beyond the traditional metrics of patient satisfaction. Instead, these outcomes need to encompass the benefits and harms, focus on outcomes relevant to the patient and provide information to inform decision-making. Therefore, radiologists need to involve ourselves as stakeholders in the design, conduct and dissemination of this research.

Carlos, Ruth C.; Buist, Diana S.M.; Wernli, Karen J.; Swan, J. Shannon

2013-01-01

41

Four-Year Treatment Outcomes of Adult Patients Enrolled in Mozambique's Rapidly Expanding Antiretroviral Therapy Program  

Microsoft Academic Search

BackgroundIn Mozambique during 2004–2007 numbers of adult patients (?15 years old) enrolled on antiretroviral therapy (ART) increased about 16-fold, from <5,000 to 79,500. All ART patients were eligible for co-trimoxazole. ART program outcomes, and determinants of outcomes, have not yet been reported.Methodology\\/Principal FindingsIn a retrospective cohort study, we investigated rates of mortality, attrition (death, loss to follow-up, or treatment cessation),

Andrew F. Auld; Francisco Mbofana; Ray W. Shiraishi; Mauro Sanchez; Charity Alfredo; Lisa J. Nelson; Tedd Ellerbrock; Rupert Kaul

2011-01-01

42

Single-center experience with ipilimumab in an expanded access program for patients with pretreated advanced melanoma.  

PubMed

Ipilimumab, a CTLA-4-blocking monoclonal antibody, improved the overall survival (OS) of advanced melanoma patients treated in prospective clinical trials. We here report a study on the outcome of patients with pretreated advanced melanoma offered ipilimumab (at its licensed dose of 3 mg/kg, every 3 wk for a total of 4 doses) in an expanded access program at a single-center university hospital. Of the 50 patients initiating ipilimumab, 31 patients completed induction therapy and 9 patients were offered reinduction therapy. Most immune-related adverse events were mild and reversible. The best objective response rate by mWHO-criteria included 1 complete response and 4 partial responses (best objective response rate of 10%). Two additional patients obtained a partial response by immune-related response criteria. Median OS was 7 months, with a 1- and 2-year survival rate of 45.2% and 28.8%, respectively. Long-term disease control with ipilimumab was observed in 7 patients of which 4 received reinduction. Baseline serum C-reactive protein (CRP) and the absolute lymphocyte count (ALC) measured on week 6 significantly correlated with OS. In conclusion, in this single-center experience with ipilimumab for advanced pretreated melanoma patients, clinical outcome was comparable with the results of published prospective studies. Reinduction therapy was of importance for maintaining long-term disease control in the majority of responding patients. Baseline CRP and ALC at week 6 deserve further prospective evaluation as prognostic and/or predictive (surrogate) markers. PMID:23502769

Wilgenhof, Sofie; Du Four, Stephanie; Vandenbroucke, Frederik; Everaert, Hendrik; Salmon, Isabelle; Liénard, Danielle; Marmol, Véronique Del; Neyns, Bart

2013-04-01

43

Scroll Expander  

NASA Astrophysics Data System (ADS)

Loss analysis of scroll expanders using R134a refrigerant was investigated and the following results were obtained. A loss estimating method of scroll expanders was proposed by using indicated power calculated by measured P-V diagram and another values. Leakage gas loss in suction process was large, so tip seals of scroll clearance are very important to realize high efficient scroll expanders. A new suction port system was designed and by this new type scroll expanders gas leakage decreased about 10% and expander efficiency increased about 10%.

Nagatomo, Shigemi; Ootaka, Toshio; Morishima, Akira

44

Expanding the guidelines for electronic communication with patients: application to a specific tool.  

PubMed

In 1998, the American Medical Informatics Association (AMIA) published a white paper entitled "Guidelines for the Clinical Use of Electronic Mail with Patients," which outlined a practical framework for this interaction. Interest in the use of other Internet-based tools, such as the World Wide Web, to enhance clinical communication is increasing. In such systems, static information can be made centrally available to patients and interactive tools such as messaging systems, schedules, and individualized care regimens can be integrated within the site. Site-specific guidelines are needed to address potential problems inherent in the particular services being offered. This article presents advice on developing site-specific guidelines, with examples, based on experience gained in developing and refining guidelines for the use of PatientWeb at the Massachusetts General Hospital Department of Neurology. PMID:11418540

Prady, S L; Norris, D; Lester, J E; Hoch, D B

2001-01-01

45

Perampanel: expanding therapeutic options for patients with medically refractory secondary generalized convulsive seizures.  

PubMed

To evaluate the efficacy of adjunctive, once-daily perampanel against secondarily generalized (SG) seizures in three Phase III trials (studies 304, 305, and 306) and their extension (study 307). The Phase III studies enrolled patients (? 12 years) with uncontrolled partial-onset seizures despite treatment with 1-3 concomitant antiepileptic drugs. Patients completing the core Phase III studies were eligible for the extension study. Endpoints included median percent change in SG seizure frequency, 50% responder (proportion of patients achieving a ? 50% reduction in SG seizure frequency), 75% response, and seizure-freedom rates. In total, 1480 patients were randomized and treated in the three perampanel Phase III trials. At baseline, 71.9% of placebo-treated and 68.4% of perampanel-treated patients had a history of SG seizures. In the individual core Phase III studies, perampanel (4-12 mg) reduced seizure frequency and improved responder rates. Consistent with this, in pooled analyses of the Phase III data, the median percent change in SG seizure frequency was -48.6%, -62.9%, and -53.3% with perampanel 4, 8, and 12 mg, respectively, vs -19.4% with placebo; 50% responder rates were 49.3%, 60.5%, and 53.7% vs 37.0% with placebo. More perampanel-treated patients had ? 75% reductions in SG seizure frequency, and seizure-freedom rates improved, compared with placebo. Improvements in seizure frequency and responder rate were maintained during the extension study. Perampanel consistently demonstrated efficacy against SG seizures when assessed using various endpoints. Furthermore, reductions in seizure frequency and improvements in responder rate were sustained with long-term perampanel treatment. PMID:23480155

Ko, D; Ramsay, R E

2013-01-01

46

Life Support for Trauma and Transport (LSTAT) Patient Care Platform: Expanding Global Applications and Impact.  

National Technical Information Service (NTIS)

The Life Support for Trauma and Transport (LSTAT(TM)) patient care platform looks like a stretcher, but is actually a portable intensive care unit and surgical platform only 15 cm thick. There is a growing body of evidence to suggest that, compared to con...

M. E. Hanson

2004-01-01

47

Contemporary Imaging of Renal Mass Patients  

PubMed Central

Purpose To evaluate the difference between radiographic size on computed tomography (CT) and the pathologic size of renal tumors using a contemporary cohort. Materials and Methods We retrospectively reviewed the records of 521 patients undergoing surgical resection of a renal mass between 2000 and 2007 who had tumor sizes recorded from both preoperative CT imaging and pathologic evaluation of the tumor specimen. Data regarding histologic tumor type were also extracted. The paired student’s t-test was utilized to compare the mean radiographic size as measured on CT with the mean pathologic size, and p values <0.05 were considered statistically significant. Results For all patients, the mean radiographic size and mean pathologic size was 4.79 and 4.69 cm, respectively (p = 0.02). Therefore, on average, radiographic size overestimated pathologic size by 1 mm. In patients with a tumor size of 4 to 7 cm, radiographic size overestimated pathologic size by 0.21 cm (p = 0.007). However, no significant difference was noted in patients with a tumor size of <4 cm or >7 cm. Conclusions Using a contemporary cohort of patients, we observed a statistically significant overestimation of renal tumor sizes by CT imaging as compared to pathologic assessment. However, the overall difference between radiographic and pathologic tumor size was 1 mm, suggesting that CT provides an accurate modality with which to estimate renal tumor size.

Kurta, Jordan M.; Thompson, R. Houston; Kundu, Shilajit; Kaag, Matthew; Manion, M. Thomas; Herr, Harry W.; Russo, Paul

2009-01-01

48

Expanding the clinical phenotype of patients with a ZDHHC9 mutation.  

PubMed

In 2007, 250 families with X-linked intellectual disability (XLID) were screened for mutations in genes on the X-chromosome, and in 4 of these families, mutations in the ZDHHC9 gene were identified. The ID was either isolated or associated with a marfanoid habitus. ZDHHC9 encodes a palmitoyl transferase that catalyzes the posttranslational modification of NRAS and HRAS. Since this first description, no additional patient with a ZDHHC9 mutation has been reported in the literature. Here, we describe a large family in which we identified a novel pathogenic ZDHHC9 nonsense mutation (p.Arg298*) by parallel sequencing of all X-chromosome exons. The mutation cosegregated with the clinical phenotype in this family. An 18-year-old patient and his 40-year-old maternal uncle were evaluated. Clinical examination showed normal growth parameters, lingual fasciculation, limited extension of the elbows and metacarpophalangeal joints, and acrocyanosis. There was neither facial dysmorphism nor marfanoid habitus. Brain MRI detected a dysplastic corpus callosum. Neuropsychological testing showed mild intellectual disability. They both displayed generalized anxiety disorder, and the younger patient also suffered from significant behavior impairment that required attention or treatment. Speech evaluation detected satisfactory spoken language since both were able to provide information and to understand conversations of everyday life. Occupational therapy examination showed impaired visual-spatial and visual-motor performance with poor drawing/graphic skills. These manifestations are not specific enough to guide ZDHHC9 screening in patients with ID, and emphasize the value of next generation sequencing for making a molecular diagnosis and genetic counseling in families with XLID. PMID:24357419

Masurel-Paulet, Alice; Kalscheuer, Vera M; Lebrun, Nicolas; Hu, Hao; Levy, Fabienne; Thauvin-Robinet, Christel; Darmency-Stamboul, Véronique; El Chehadeh, Salima; Thevenon, Julien; Chancenotte, Sophie; Ruffier-Bourdet, Marie; Bonnet, Marlène; Pinoit, Jean-Michel; Huet, Frédéric; Desportes, Vincent; Chelly, Jamel; Faivre, Laurence

2014-03-01

49

Patient evaluation. Laboratory and imaging studies.  

PubMed

The evaluation of urolithiases, in terms of calculus detection and evaluation of the morphology and function of the kidneys, continues to be refined with advances in imaging technology. The most significant recent advance is use of helical or spiral CT scan for the accurate delineation of renal and ureteral calculi in the acute setting. This may provide an accurate, rapid, and cost-effective method of patient evaluation. The alternative approach is to use plain abdominal radiography to detect renal or ureteral calculi. Noncontrast-enhanced helical or spiral CT scanning has its greatest impact in patients with negative abdominal radiographs or in those patients with suspected urinary colic in whom renal but not ureteral calculi are seen. A supplemental intravenous urogram can be used, as appropriate, to evaluate renal function and degree of obstruction on both the involved and uninvolved side. Combined abdominal radiography and sonography may be used for calculus detection and demonstration of obstruction. Sonography is an operator-dependent technique requiring expertise, experience, and adequate imaging equipment for satisfactory results. Physiologic study of renal blood flow and urinary dynamics using Doppler techniques are possible, though considered to be in the realm of clinical investigation at this time. Sonography has a valuable role in the serial evaluation of chronic stone formers with a history of recurrent urinary infections related to obstruction or reflux. Radiography, fluoroscopy, and sonography are the imaging, methods used in ESWL treatment in preprocedure and postprocedure. PMID:9048855

Begun, F P; Foley, W D; Peterson, A; White, B

1997-02-01

50

Scroll Expander  

NASA Astrophysics Data System (ADS)

Scroll expander for room air conditioning system was developed. The performance characteristics of scroll expander using R134a refrigerant were investigated experimentally. The following results were obtained. (1) Shaft power index Nexp was proposed newly and effective to evaluate the shaft power of scroll expander. (2) Shaft power index Nexp and expander efficiency ? exp increased with the increase in the pressure ratio in the range of the pressure ratio over 2.6. (3) Mass flow rate difference between measured and theoretical values decreased with the increase in the rotational speed and the decrease in the pressure ratio of expander. Mass flow rate ratio ? of 0.98 to 0.9 were obtained at these operating conditions. (4) Maximum shaft power index Nexp of 0.8 and maximum expander efficiency ? exp of 0.74 were obtained at the pressure ratio of 3.7 and rotational speed of 50 (1/s).

Nagatomo, Shigemi; Ootaka, Toshio; Morishima, Akira

51

Patient-Adaptive Reconstruction and Acquisition in Dynamic Imaging with Sensitivity Encoding (PARADISE)  

PubMed Central

MR imaging of the human heart without explicit cardiac synchronization promises to extend the applicability of cardiac MR to a larger patient population and potentially expand its diagnostic capabilities. However, conventional non-gated imaging techniques typically suffer from low image quality or inadequate spatio-temporal resolution and fidelity. Patient-Adaptive Reconstruction and Acquisition in Dynamic Imaging with Sensitivity Encoding (PARADISE) is a highly-accelerated non-gated dynamic imaging method that enables artifact-free imaging with high spatio-temporal resolutions by utilizing novel computational techniques to optimize the imaging process. In addition to using parallel imaging, the method gains acceleration from a physiologically-driven spatio-temporal support model; hence, it is doubly accelerated. The support model is patient-adaptive, i.e., its geometry depends on dynamics of the imaged slice, e.g., subject’s heart-rate and heart location within the slice. The proposed method is also doubly adaptive as it adapts both the acquisition and reconstruction schemes. Based on the theory of time-sequential sampling, the proposed framework explicitly accounts for speed limitations of gradient encoding and provides performance guarantees on achievable image quality. The presented in-vivo results demonstrate the effectiveness and feasibility of the PARADISE method for high resolution non-gated cardiac MRI during a short breath-hold.

Sharif, Behzad; Derbyshire, J. Andrew; Faranesh, Anthony Z.; Bresler, Yoram

2010-01-01

52

Expanded Notation  

NSDL National Science Digital Library

With this step-by-step, interactive video from StudyJams students can earn more about expanded notation. Expanded notation, also called expanded form, is a handy way to write numbers that shows the place value of each digit. It looks like an addition problem and will help you break numbers down and understand their place value. A short, self-checking quiz is also included with this link.

Scholastic, Studyjam Â.

2011-06-28

53

Expanding the boundaries of informed consent: disclosing alcoholism and HIV status to patients.  

PubMed

Since informed consent became legally required in the therapeutic setting, the risks physicians were to disclose have been limited to the risks of particular procedures. Two recent court decisions in which disclosure of surgeons' alcoholism and positive human immunodeficiency virus status was required may begin to erode that limit. The grounds for this expansion of disclosure requirements were inherent in the 20-year-old "materiality" standard for disclosure; nevertheless, the change they signal is profound. These cases may signal a trend that, in the long term, could result in a shift in physician-patient communication and a significant loss of privacy for physicians. PMID:1497019

Spielman, B

1992-08-01

54

Fulvestrant: expanding the endocrine treatment options for patients with hormone receptor-positive advanced breast cancer.  

PubMed

With the aromatase inhibitors (AIs) replacing tamoxifen as the first-line treatment for postmenopausal women with hormone receptor-positive early and advanced breast cancer, there is a need to evaluate appropriate endocrine treatment options following AI failure. However, until recently, there were no Phase III trial data in this area. Fulvestrant (Faslodex) is an oestrogen receptor antagonist utilised for the treatment of postmenopausal women with locally advanced or metastatic breast cancer following progression or recurrence on anti-oestrogen therapy. Fulvestrant has a mode of action that is distinct from the AIs and the selective oestrogen receptor modulators, and thus may offer an effective treatment option in the post-AI setting. The Evaluation of Faslodex and Exemestane Clinical Trial (EFECT) is the first Phase III trial to evaluate the efficacy and tolerability of fulvestrant and the steroidal AI, exemestane, in patients with locally advanced or metastatic breast cancer who have progressed or recurred while receiving a non-steroidal AI. EFECT confirmed that fulvestrant and exemestane offer effective treatment options in this setting. Similar efficacy was seen in both treatment groups and there were no significant differences in reported adverse events between fulvestrant and exemestane. The EFECT data provide further evidence for the activity of fulvestrant in the treatment of advanced breast cancer. Other ongoing fulvestrant trials will further define its full role, including the potential for a high-dose regimen, combination of fulvestrant with an AI, and identification of clinical and biological markers to help in targeting those patients who are most likely to respond to treatment. PMID:18353647

Chia, Stephen; Gradishar, William

2008-04-01

55

Identification of an HD patient with a (CAG) 180 repeat expansion and the propagation of highly expanded CAG repeats in lambda phage  

Microsoft Academic Search

The Huntington’s disease mutation has been identified as a CAG\\/polyglutamine repeat expansion in a large gene of unknown\\u000a function. In order to develop the transgenic systems necessary to uncover the molecular pathology of this disorder, it is\\u000a necessary to be able to manipulate highly expanded CAG repeats in a cloned form. We have identified a patient with an expanded\\u000a allele

Kirupa Sathasivam; Iheoma Amaechi; Laura Mangiarini; Gillian Bates

1997-01-01

56

The expanded Global Registry of Acute Coronary Events: Baseline characteristics, management practices, and hospital outcomes of patients with acute coronary syndromes  

Microsoft Academic Search

BACKGROUND: The Global Registry of Acute Coronary Events (GRACE)-a prospective, multinational study of patients hospitalized with acute coronary syndromes (ACSs)-was designed to improve the quality of care for patients with an ACS. Expanded GRACE aims to test the feasibility of a simplified data collection tool and provision of quarterly feedback to index individual hospital management practices to an international reference

Shaun G. Goodman; Wei Huang; Andrew T. Yan; Andrzej Budaj; Brian M. Kennelly; Joel M. Gore; Keith A. A. Fox; Robert J. Goldberg; Frederick A. Anderson Jr

2009-01-01

57

Wave Expander  

Microsoft Academic Search

A schematic description of the design of a wave expander is presented. A mathematical model of the operation process has been substantiated. The operational characteristics of a reciprocating wave expander have been obtained within the framework of the numerical integration of the system of nonstationary gas-dynamics equations in a one-dimensional formulation. The stages of the operation process have been considered

S. V. Bulovich; R. L. Petrov

2002-01-01

58

Imaging in Patients with Merkel Cell Carcinoma  

PubMed Central

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor of the skin with a mortality rate of approximately 25% (Peloschek et al., 2010). Accurate assessment of nodal involvement in patients with MCC predicts significantly overall outcome (Smith et al., 2012 and Ortin-Perez et al., 2007). Due to the rarity of this highly aggressive disease, only a few imaging reports on MCC were published, and subsequently still to date no accepted imaging algorithm for MCC is available. For primary staging of MCC, general recommendations have included ultrasonography, chest X-ray CT, and MRI, but recent articles show that the use of sentinel node and FDG-PET/PET-CT is gaining more and more importance.

Enzenhofer, Elisabeth; Ubl, Philipp; Czerny, Christian; Erovic, Boban M.

2013-01-01

59

Imaging in patients with merkel cell carcinoma.  

PubMed

Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine tumor of the skin with a mortality rate of approximately 25% (Peloschek et al., 2010). Accurate assessment of nodal involvement in patients with MCC predicts significantly overall outcome (Smith et al., 2012 and Ortin-Perez et al., 2007). Due to the rarity of this highly aggressive disease, only a few imaging reports on MCC were published, and subsequently still to date no accepted imaging algorithm for MCC is available. For primary staging of MCC, general recommendations have included ultrasonography, chest X-ray CT, and MRI, but recent articles show that the use of sentinel node and FDG-PET/PET-CT is gaining more and more importance. PMID:23476783

Enzenhofer, Elisabeth; Ubl, Philipp; Czerny, Christian; Erovic, Boban M

2013-01-01

60

Low frequency of GITR+ T cells in ex vivo and in vitro expanded Treg cells from type 1 diabetic patients.  

PubMed

Reported alterations in T(reg) cells from type 1 diabetes (T1D) patients led us to a revision of their phenotypical features compared with controls. A fine cytometric analysis was designed for their characterization, using a panel of markers including FOXP3, CTLA4, glucocorticoid-induced TNFR family related (GITR) and CD127. The frequency of peripheral CD4(+)CD25(hi) T(reg) cells was similar between samples. However, the yield of sorted T(reg) cells was significantly lower in patients than in controls. When comparing the T(reg)-cell phenotype between samples, the only difference concerned the expression of GITR. A significant decrease of GITR(+) cells and GITR mean fluorescence intensity within the T(reg)-cell population, and to a lesser extent in the effector population, was observed in T1D compared with controls. Moreover, GITR expression was analyzed in several conditions of T-cell activation and differences were only observed in T1D T(reg) cells versus controls when responding to sub-optimal stimulation, that is, soluble anti-CD3 or medium alone but not in the presence of anti-CD3-/anti-CD28-coated beads. However, expanded T1D T(reg)-cell-mediated suppression was as efficient as that mediated by their control counterparts, showing no association between their regulatory capacity and the reduced GITR. Our results show a higher susceptibility to apoptosis in patients' versus controls' T(reg) cells, suggesting that GITR is a T(reg)-cell marker that would be primarily involved in T(reg)-cell survival rather than in their suppressor function. PMID:23929911

Xufré, Cristina; Costa, Manuela; Roura-Mir, Carme; Codina-Busqueta, Eva; Usero, Lorena; Pizarro, Eduarda; Obiols, Gabriel; Jaraquemada, Dolores; Martí, Mercè

2013-10-01

61

Pigmented villonodular synovitis: MR imaging in pediatric patients  

Microsoft Academic Search

Objectives: To describe the usefulness of gradient-echo imaging and contrast-enhanced MR imaging in diagnosing and assessing the extent of pigmented villonodular synovitis (PVNS) in pediatric patients. Patients and methods : Retrospective analysis of five pediatric patients (median age 14 years) with PVNS of the knee examined with a 1.5-T unit. Signal characteristics were obtained comparing T1- and proton-density (PD)-weighted imaging with

Boris P. Eckhardt; Ramiro J. Hernandez

2004-01-01

62

Body image concerns of reconstructive surgery patients: an underrecognized problem.  

PubMed

This study assessed the body image concerns of reconstructive plastic surgery patients. Forty-three reconstructive surgery patients completed two measures of body image. Responses were compared with a group of patients seeking cosmetic procedures. The two groups did not differ in the degree of dissatisfaction with their overall appearance or dissatisfaction with the specific feature for which they were seeking surgery. Reconstructive patients did consider themselves less healthy and less invested in their appearance than did cosmetic patients. Seven of the reconstructive surgery patients (all scar revision patients) reported a level of dissatisfaction and preoccupation consistent with the psychiatric diagnostic of body dysmorphic disorder. These results underscore the importance of screening for body image dissatisfaction in persons with an objective deformity. Plastic surgeons are in an optimal position to identify body image concerns in these patients and provide appropriate referrals for psychotherapy. PMID:9555996

Sarwer, D B; Whitaker, L A; Pertschuk, M J; Wadden, T A

1998-04-01

63

Dynamic imaging of seizure activity in pediatric epilepsy patients  

PubMed Central

Objective To investigate the feasibility of using noninvasive EEG source imaging approach to image continuous seizure activity in pediatric epilepsy patients. Methods Nine pediatric patients with medically intractable epilepsy were included in this study. Eight of the patients had extratemporal lobe epilepsy and one had temporal lobe epilepsy. All of the patients underwent resective surgery and seven of them underwent intracranial EEG (iEEG) monitoring. The ictal EEG was analyzed using a noninvasive dynamic seizure imaging (DSI) approach. The DSI approach separates scalp EEGs into independent components and extracts the spatio-temporal ictal features to achieve dynamic imaging of seizure sources. Surgical resection and intracranial recordings were used to validate the noninvasive imaging results. Results The DSI determined seizure onset zones (SOZs) in these patients were localized within or in close vicinity to the surgically resected region. In the seven patients with intracranial monitoring, the estimated seizure onset sources were concordant with the seizure onset zones of iEEG. The DSI also localized the multiple foci involved in the later seizure propagation, which were confirmed by the iEEG recordings. Conclusions Dynamic seizure imaging can noninvasively image the seizure activations in pediatric patients with both temporal and extratemporal lobe epilepsy. Significance EEG seizure imaging can potentially be used to noninvasively image the SOZs and aid the pre-surgical planning in pediatric epilepsy patients.

Lu, Yunfeng; Yang, Lin; Worrell, Gregory A.; Brinkmann, Benjamin; Nelson, Cindy; He, Bin

2012-01-01

64

Exercise thallium imaging in patients with diabetes mellitus. Prognostic implications  

SciTech Connect

We used exercise thallium 201 imaging in 123 patients with diabetes mellitus (77 men and 46 women, aged 56 +/- 8 years), 75% of whom had angina pectoris (typical or atypical). During exercise testing, 18 patients (15%) had angina pectoris, 28 (23%) had ischemic ST changes, and 69 (56%) had abnormal thallium images. During follow-up (up to 36 months), there were 12 cardiac events; four patients died of cardiac causes and eight had nonfatal acute myocardial infarction. Univariate and multivariate survival analysis identified two independent predictors of cardiac events: the event rate was significantly less in patients with normal images and exercise heart rate over 120 beats per minute than in patients with abnormal images and exercise heart rate of 120 beats per minute or less (0% vs 22%). The patients with abnormal images or exercise heart rate of 120 beats per minute or less had an intermediate event rate (11.5%). Furthermore, two of the 54 patients with normal images and ten of 69 patients with abnormal images had subsequent cardiac events. Thus, exercise thallium imaging is useful in risk stratification in patients with diabetes mellitus.

Felsher, J.; Meissner, M.D.; Hakki, A.H.; Heo, J.; Kane-Marsch, S.; Iskandrian, A.S.

1987-02-01

65

Expanding Gravity  

NASA Astrophysics Data System (ADS)

Newton's gravitational constant Gn and Laws of Gravity are based upon observations in our solar system. Mysteries appear when they are used far outside our solar system Apparently, Newton's gravitational constant can not be applied at large distances. Dark matter was needed to explain the observed flat rotational velocity curves of spiral galaxies (Rubin), and of groups of remote galaxies (Zwicky). Our expansion of Newton's gravitational constant Gn as a power series in distance r, is sufficient to explain these observations without using dark matter. This is different from the MOND theory of Milgrom involving acceleration. Also, our Expanded Gravitational Constant (EGC) can show the correct use of the red shift. In addition to the Doppler contribution, there are three other contributions and these depend only upon gravity. Thus, velocity observations only based on the red shift can not be used to support the concept of the expanding universe, the accelerating expansion, or dark energy. Our expanded gravity constant can predict and explain Olbers' paradox (dark sky), and the temperature of the CMB (cosmic microwave background). Thus, CMB may not support the big bang and inflation.

Aisenberg, Sol

2005-04-01

66

Small bowel imaging in managing Crohn's disease patients.  

PubMed

The small bowel is essential to sustain alimentation and small bowel Crohn's disease (CD) may severely limit its function. Small bowel imaging is a crucial element in diagnosing small bowel CD, and treatment control with imaging is increasingly used to optimize the patients outcome. Thereby, capsule endoscopy, Balloon-assisted enteroscopy, and Magnetic resonance imaging have become key players to manage CD patients. In this review, role of small bowel imaging is detailed discussed for use in diagnosing and managing Crohn's disease patients. PMID:22474438

Albert, Jörg G

2012-01-01

67

Extrahepatic abdominal imaging in patients with malignancy: comparison of MR imaging and helical CT in 164 patients.  

PubMed

The purpose of this study was to compare the performance of magnetic resonance (MR) imaging using currently available techniques with contrast-enhanced single-phase helical computed tomography (CT) in depicting extrahepatic disease in patients with malignancy. At two institutions, 164 patients with known or suspected malignancy underwent abdominal imaging with contrast-enhanced helical CT and MR imaging. The prospective interpretations of the CT scans and MR examinations were used to assess the sensitivity of each imaging test in detecting benign and malignant extrahepatic disease at 17 anatomic sites. Imaging findings were compared with results of surgery in 57 patients and with the combined results of image-guided biopsy, follow-up cross-sectional imaging studies, other concurrent imaging tests, and clinical follow-up. For the 164 patients, helical CT scans depicted 221 of 316 (70%) sites of proven extrahepatic tumor compared with 288 sites (91%) (P < 0.0001) for MR imaging. For the 57 patients who underwent exploratory laparotomy, helical CT scans depicted 101 of 154 (66%) findings of surgically confirmed extrahepatic tumor compared with MR imaging, which depicted 139 sites (90%) (P < 0.0001). Anatomic sites at which MR imaging showed a significantly greater detection of extrahepatic tumor included the peritoneum, bowel, and vascular and osseous structures. For depiction of benign extrahepatic disease, there was no significant difference between helical CT and MR imaging. MR imaging, using currently available T1-weighted, RARE T2-weighted, and gadolinium-enhanced imaging, is effective in depicting extrahepatic disease in patients with malignancy. Compared with single-phase helical CT scanning, MR imaging shows an advantage in depicting tumor involving the peritoneum, omentum, bowel, and osseous and vascular structures. PMID:10931590

Low, R N; Semelka, R C; Worawattanakul, S; Alzate, G D

2000-08-01

68

Preprocedural Imaging for Patients with Atrial Fibrillation and Heart Failure  

PubMed Central

Various electrophysiological procedures and device implantation has been shown to improve morbidity and mortality in patients with atrial fibrillation (AF) and patients with heart failure (HF). Non-invasive cardiac imaging is used extensively in the pre-procedural patient selection and for procedural guidance. In this review, we will discuss the application of pre-procedural cardiac imaging in patients with AF prior to pulmonary vein and left atrial ablation as well as insertion of left atrial occluder device. We also discuss the role of non-invasive cardiac imaging in the selection of appropriate HF patients for device therapy as well as their use in guiding implantation of biventricular pacemaker for cardiac resynchronization therapy by assessing left ventricular ejection fraction, coronary venous anatomy, mechanical dyssynchrony and myocardial scar. We describe new research associated with pre-procedural imaging in these patient cohorts.

Thai, Wai-ee; Wai, Bryan; Truong, Quynh A.

2012-01-01

69

Safe magnetic resonance image scanning of the pacemaker patient: current technologies and future directions.  

PubMed

Magnetic resonance imaging (MRI) is the imaging modality of choice in many clinical situations, and its use is likely to grow due to expanding indications and an ageing population. Many patients with implantable devices are denied MRI except in cases of urgent need, and when scans must be performed they are complicated by the need for burdensome and costly personnel and monitoring requirements that have the net effect of restricting access to scans. Several small studies, enrolling a total of 344 patients, suggest that some patients with conventional systems may undergo MR examinations without clinically overt adverse events. However, a number of potential interactions exist between implantable cardiac devices and the static and gradient magnetic fields and modulated radio frequency (RF) fields generated during MR scans; nearly all studies have reported pacing capture threshold changes, troponin elevations, ectopy, unpredictable reed switch behaviour, and other 'subclinical' issues with pacemakers and implantable cardioverter-defibrillators (ICDs) in patients who have undergone MRI. Attention has turned to devices that are specifically designed to be safe in the MRI environment. A clinical study of one such device documented its ability to be exposed to MRI in a 1.5 T scanner without adverse impact on patient outcomes or pacemaker system function. Such new technologies may enable scanning of pacemaker and ICD patients with reduced concerns regarding the short- and long-term effects of MRI. As importantly, these devices may increase the number of centres that are able to safely perform MRI and, thus, expand access to scans for patients with these devices. PMID:22237585

Jung, Werner; Zvereva, Vlada; Hajredini, Bajram; Jäckle, Sebastian

2012-05-01

70

Body Image Disturbance in Patients with Acne Vulgaris  

PubMed Central

Psychosocial outcome measures, which attempt to examine acne from the patient's perspective, have become increasingly important in dermatology research. One such measure is the Body Image Disturbance Questionnaire. The authors' primary aim was to determine the validity and internal consistency of the Body Image Disturbance Questionnaire in patients with acne vulgaris. The secondary aim was to investigate the relationship between body image disturbance and quality of life. This cross-sectional investigation included 52 consecutive acne patients presenting to an outpatient dermatology clinic. Subjects completed the Body Image Disturbance Questionnaire, Skindex-16, and other body image and psychosocial functioning measures. An objective assessment of acne was performed. The Body Image Disturbance Questionnaire was internally consistent and converged with other known body image indices. Body Image Disturbance Questionnaire scores also correlated with Skindex-16 scores, confirming that quality of life and body image are related psychosocial constructs. The Body Image Disturbance Questionnaire appears to be an accurate instrument that can assess appearance-related concern and impairment in patients with acne vulgaris. Limitations include a small sample size and the cross-sectional design.

Bowe, Whitney P.; Crerand, Canice E.; Margolis, David J.; Shalita, Alan R.

2011-01-01

71

Expanded Very Large Array Observations of Galactic Supernova Remnants: Wide-field Continuum and Spectral-index Imaging  

NASA Astrophysics Data System (ADS)

The radio continuum emission from the Galaxy has a rich mix of thermal and non-thermal emission. This very richness makes its interpretation challenging since the low radio opacity means that a radio image represents the sum of all emission regions along the line of sight. These challenges make the existing narrowband radio surveys of the Galactic plane difficult to interpret: e.g., a small region of emission might be a supernova remnant (SNR) or an H II region, or a complex combination of both. Instantaneous wide bandwidth radio observations in combination with the capability for high-resolution spectral-index mapping can be directly used to disentangle these effects. Here we demonstrate simultaneous continuum and spectral-index imaging capability at the full continuum sensitivity and resolution using newly developed wide-band wide-field imaging algorithms. Observations were conducted in the L and C bands with a total bandwidth of 1 and 2 GHz, respectively. We present preliminary results in the form of a full-field continuum image covering the wide-band sensitivity pattern of the EVLA centered on a large but poorly studied SNR (G55.7 + 3.4) and relatively narrower field continuum and spectral-index maps of three fields containing SNR and diffused thermal emission. We demonstrate that spatially resolved spectral-index maps differentiate regions with emission of different physical origins (spectral-index variation across composite SNRs and separation of thermal and non-thermal emission), superimposed along the line of sight. The wide-field image centered on the SNR G55.7+3.4 also demonstrates the excellent wide-field wide-band imaging capability of the EVLA.

Bhatnagar, S.; Rau, U.; Green, D. A.; Rupen, M. P.

2011-09-01

72

EXPANDED VERY LARGE ARRAY OBSERVATIONS OF GALACTIC SUPERNOVA REMNANTS: WIDE-FIELD CONTINUUM AND SPECTRAL-INDEX IMAGING  

SciTech Connect

The radio continuum emission from the Galaxy has a rich mix of thermal and non-thermal emission. This very richness makes its interpretation challenging since the low radio opacity means that a radio image represents the sum of all emission regions along the line of sight. These challenges make the existing narrowband radio surveys of the Galactic plane difficult to interpret: e.g., a small region of emission might be a supernova remnant (SNR) or an H II region, or a complex combination of both. Instantaneous wide bandwidth radio observations in combination with the capability for high-resolution spectral-index mapping can be directly used to disentangle these effects. Here we demonstrate simultaneous continuum and spectral-index imaging capability at the full continuum sensitivity and resolution using newly developed wide-band wide-field imaging algorithms. Observations were conducted in the L and C bands with a total bandwidth of 1 and 2 GHz, respectively. We present preliminary results in the form of a full-field continuum image covering the wide-band sensitivity pattern of the EVLA centered on a large but poorly studied SNR (G55.7 + 3.4) and relatively narrower field continuum and spectral-index maps of three fields containing SNR and diffused thermal emission. We demonstrate that spatially resolved spectral-index maps differentiate regions with emission of different physical origins (spectral-index variation across composite SNRs and separation of thermal and non-thermal emission), superimposed along the line of sight. The wide-field image centered on the SNR G55.7+3.4 also demonstrates the excellent wide-field wide-band imaging capability of the EVLA.

Bhatnagar, S.; Rau, U.; Rupen, M. P. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Green, D. A., E-mail: sbhatnag@nrao.edu, E-mail: rurvashi@nrao.edu, E-mail: mrupen@nrao.edu, E-mail: dag9@cam.ac.uk [Astrophysics Group, Cavendish Laboratory, Cambridge CB3 0HE (United Kingdom)

2011-09-20

73

Method of signal reception in the expanded dynamic range of the photomultiplier tube for an imaging plate  

NASA Astrophysics Data System (ADS)

A signal reception system based on simultaneous measurement of signals from the anode and one dynode of the photomultiplier tube has been developed for the readout of an imaging plate (photostimulated luminescence screen). This system is able to cover a linear-dynamic range of more than five orders of magnitude using a single photomultiplier tube with a high accuracy.

Yamamoto, Masaya; Teng, Yongjie; Aoki, Takuya; Izumi, Takatoshi

2007-03-01

74

Visualization of expanding laser-ablation plume by a proposed frequency up-converted infrared spectroscopic imaging  

Microsoft Academic Search

Observing temporal and spatial distribution of infrared (IR) radiation is restricted by the lack of a fast-gated IR detector. To overcome this problem, frequency up-conversion detection of IR radiation in a nonlinear crystal has been developed by several investigators. We have proposed the frequency up-conversion imaging of an IR degenerate four-wave mixing (DFWM) signal. DFWM produce a coherent signal, so

K. Morishita; Y. Higuchi; T. Okada

1999-01-01

75

Compact storage of medical images with patient information.  

PubMed

Digital watermarking is a technique of hiding specific identification data for copyright authentication. This technique is adapted here for interleaving patient information with medical images to reduce storage and transmission overheads. The text data are encrypted before interleaving with images to ensure greater security. The graphical signals are compressed and subsequently interleaved with the image. Differential pulse-code-modulation and adaptive-delta-modulation techniques are employed for data compression, and encryption and results are tabulated for a specific example. PMID:11759838

Acharya, R; Anand, D; Bhat, S; Niranjan, U C

2001-12-01

76

Body Image Screening for Cancer Patients Undergoing Reconstructive Surgery  

PubMed Central

Objectives Body image is a critical issue for cancer patients undergoing reconstructive surgery, as they can experience disfigurement and functional impairment. Distress related to appearance changes can lead to various psychosocial difficulties, and patients are often reluctant to discuss these issues with their healthcare team. Our goals were to design and evaluate a screening tool to aid providers in identifying patients who may benefit from referral for specialized psychosocial care to treat body image concerns. Methods We designed a brief 4-item instrument and administered it at a single time point to cancer patients who were undergoing reconstructive treatment. We used simple and multinomial regression models to evaluate whether survey responses, demographic, or clinical variables predicted interest and enrollment in counseling. Results Over 95% of the sample (n = 248) endorsed some concerns, preoccupation, or avoidance due to appearance changes. Approximately one-third of patients were interested in obtaining counseling or additional information to assist with body image distress. Each survey item significantly predicted interest and enrollment in counseling. Concern about future appearance changes was the single best predictor of counseling enrollment. Sex, age, and cancer type were not predictive of counseling interest or enrollment. Conclusions We present initial data supporting use of the Body Image Screener for Cancer Reconstruction. Our findings suggest benefits of administering this tool to patients presenting for reconstructive surgery. It is argued that screening and treatment for body image distress should be provided to this patient population at the earliest possible time point.

Fingeret, Michelle Cororve; Nipomnick, Summer; Guindani, Michele; Baumann, Donald; Hanasono, Matthew; Crosby, Melissa

2014-01-01

77

Expanding the clinical spectrum of the 16p11.2 chromosomal rearrangements: three patients with syringomyelia  

PubMed Central

16p11.2 rearrangements are associated with developmental delay, cognitive impairment, autism spectrum disorder, behavioral problems (especially attention-deficit hyperactivity disorder), seizures, obesity, dysmorphic features, and abnormal head size. In addition, congenital anomalies and abnormal brain findings were frequently observed in patients with these rearrangements. We identified and performed a detailed microarray, phenotypic, and radiological characterization of three new patients with 16p11.2 rearrangements: two deletion patients and one patient with the reciprocal duplication. All patients have a heterozygous loss (deletion) or gain (duplication) corresponding to chromosomal coordinates (chr16: 29?528?190–30?107?184) with a minimal size of 579?kb. The deletion patients had language delay and learning disabilities and one met criteria for pervasive developmental disorder not otherwise specified. The duplication patient received a diagnosis of autism and had academic deficits and behavioral problems. The patients with deletion had long cervicothoracic syringomyelia and the duplication patient had long thoracolumbar syringomyelia. The syringomyelia in one patient with deletion was associated with Chiari malformation. Our findings highlight the broad spectrum of clinical and neurological manifestations in patients with 16p11.2 rearrangements. Our observation suggests that genes (or a single gene) within the implicated interval have significant roles in the pathogenesis of syringomyelia. A more comprehensive and systematic research is warranted to study the frequency and spectrum of malformations in the central nervous system in these patients.

Schaaf, Christian P; Goin-Kochel, Robin P; Nowell, Kerri P; Hunter, Jill V; Aleck, Kirk A; Cox, Sarah; Patel, Ankita; Bacino, Carlos A; Shinawi, Marwan

2011-01-01

78

Study of Patient's Self-Image during Orthodontic Treatment.  

National Technical Information Service (NTIS)

There has been little research done that has attempted to study the patient's self-image and record what changes occur with a correction of the patient's malocclusion through orthodontic treatment. A study was done to determine what changes occur in the o...

B. B. Jacobus

1985-01-01

79

Zirconium-89 Labeled Antibodies: A New Tool for Molecular Imaging in Cancer Patients  

PubMed Central

Antibody based positron emission tomography (immuno-PET) imaging is of increasing importance to visualize and characterize tumor lesions. Additionally, it can be used to identify patients who may benefit from a particular therapy and monitor the therapy outcome. In recent years the field is focused on 89Zr, a radiometal with near ideal physical and chemical properties for immuno-PET. In this review we will discuss the production of??89Zr, the bioconjugation strategies, and applications in (pre-)clinical studies of??89Zr-based immuno-PET in oncology. To date, 89Zr-based PET imaging has been investigated in a wide variety of cancer-related targets. Moreover, clinical studies have shown the feasibility for 89Zr-based immuno-PET to predict and monitor treatment, which could be used to tailor treatment for the individual patient. Further research should be directed towards the development of standardized and robust conjugation methods and improved chelators to minimize the amount of released Zr4+ from the antibodies. Additionally, further validation of the imaging method is required. The ongoing development of new 89Zr-labeled antibodies directed against novel tumor targets is expected to expand applications of??89Zr-labeled immuno-PET to a valuable method in the medical imaging.

van de Watering, Floor C. J.; Rijpkema, Mark; Perk, Lars; Brinkmann, Ulrich; Oyen, Wim J. G.; Boerman, Otto C.

2014-01-01

80

Plerixafor and G-CSF for autologous stem cell mobilization in patients with NHL, Hodgkin's lymphoma and multiple myeloma: results from the expanded access program.  

PubMed

Before US regulatory approval, an expanded access program provided plerixafor to patients with non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HD) or multiple myeloma (MM) who had not previously failed mobilization and were otherwise candidates for auto-SCT. Patients received granulocyte-CSF (G-CSF) 10?mcg/kg daily and plerixafor 0.24?mg/kg starting on day 4 with apheresis on day 5; all repeated daily until collection was complete. Overall, 104 patients received ?1 dose of plerixafor. The addition of plerixafor to G-CSF resulted in a median threefold increase in peripheral blood CD34+ cell count between days 4 and 5. Among 43 NHL patients, 74% met the target of ?5 × 10(6) CD34+ cells/kg (median, 1 day apheresis, range 1-5 days); among 7 HD patients, 57% met the target of ?5 × 10(6) CD34+ cells/kg (median, 2 days apheresis, range 1-3); and among 54 MM patients, 89% met the target of ?6 × 10(6) CD34+ cells/kg (median, 1 day apheresis, range 1-4). Overall, 93% of patients had ?2 × 10(6) CD34+ cells/kg collected within 1-3 days. Plerixafor-related toxicities were minimal. Engraftment kinetics, graft durability and transplant outcomes demonstrated no unexpected outcomes. Efficacy and safety results were similar to results in phase II and III clinical trials. PMID:23178544

Shaughnessy, P; Uberti, J; Devine, S; Maziarz, R T; Vose, J; Micallef, I; Jacobsen, E; McCarty, J; Stiff, P; Artz, A; Ball, E D; Berryman, R; Dugan, M; Joyce, R; Hsu, F J; Johns, D; McSweeney, P

2013-06-01

81

Psychopathology and Body Image in Cosmetic Surgery Patients  

Microsoft Academic Search

.   The purpose of this study was to investigate the presence of psychiatric symptoms and evaluate the perceptive, cognitive,\\u000a and behavioral aspects of body image in cosmetic surgery patients. These parameters of 20 cosmetic patients and of 20 control\\u000a patients matched for age, gender, education, and marital status who attended the general surgery department for minor surgery\\u000a were compared in

Serpil Vargel; Aylin Ulu?ahin

2001-01-01

82

Expanded CTG repeat demarcates a boundary for abnormal CpG methylation in myotonic dystrophy patient tissues  

PubMed Central

Myotonic dystrophy (DM1) affects multiple organs, shows age-dependent progression and is caused by CTG expansions at the DM1 locus. We determined the DM1 CpG methylation profile and CTG length in tissues from DM1 foetuses, DM1 adults, non-affected individuals and transgenic DM1 mice. Analysis included CTCF binding sites upstream and downstream of the CTG tract, as methylation-sensitive CTCF binding affects chromatinization and transcription of the DM1 locus. In humans, in a given foetus, expansions were largest in heart and smallest in liver, differing by 40–400 repeats; in adults, the largest expansions were in heart and cerebral cortex and smallest in cerebellum, differing by up to 5770 repeats in the same individual. Abnormal methylation was specific to the mutant allele. In DM1 adults, heart, liver and cortex showed high-to-moderate methylation levels, whereas cerebellum, kidney and skeletal muscle were devoid of methylation. Methylation decreased between foetuses and adults. Contrary to previous findings, methylation was not restricted to individuals with congenital DM1. The expanded repeat demarcates an abrupt boundary of methylation. Upstream sequences, including the CTCF site, were methylated, whereas the repeat itself and downstream sequences were not. In DM1 mice, expansion-, tissue- and age-specific methylation patterns were similar but not identical to those in DM1 individuals; notably in mice, methylation was present up- and downstream of the repeat, but greater upstream. Thus, in humans, the CpG-free expanded CTG repeat appears to maintain a highly polarized pattern of CpG methylation at the DM1 locus, which varies markedly with age and tissues.

Lopez Castel, Arturo; Nakamori, Masayuki; Tome, Stephanie; Chitayat, David; Gourdon, Genevieve; Thornton, Charles A.; Pearson, Christopher E.

2011-01-01

83

Imaging of patients with congenital heart disease  

Microsoft Academic Search

Congenital defects most-commonly affect the heart, with an estimated incidence of up to 10 in 1,000 live births. Over the past few decades, mortality has decreased and subsequent survival has increased; approximately 90% of all patients with congenital heart disease (CHD) reach adulthood. Echocardiography is sufficient in most cases for prenatal and postnatal diagnosis of CHD and to plan an

Albert de Roos; Arno A. W. Roest

2011-01-01

84

Magnetic resonance imaging in patients with panhypopituitarism  

Microsoft Academic Search

Primary panhypopituitarism consists of functional deficiency of the anterior pituitary lobe, which appears during infancy or adolescence. The magnetic resonance findings in 10 patients with a history of primary hopopituitarism are presented. The findings include: reduced pituitary size in all cases: partially (8 cases) or totally (2 cases) empty sella; thin (4 cases), partially visible (3 cases) or absent (2

R. S. Pozzi Mucelli; F. Frezza; S. Magnaldi; G. Proto

1992-01-01

85

A patient positioning system for the ESRF medical imaging facility  

NASA Astrophysics Data System (ADS)

The medical imaging facility of the ESRF is devoted to human coronary angiography, computed tomography, diffraction enhanced imaging (DEI), bronchography, and also radiation therapy programs. Most of the imaging is performed in a satellite building located at 150 m from the wiggler source (H. Elleaume et al., Nucl. Instr. and Meth. A 428 (1999) 513). A multi-purpose device known as the Patient Positioning System (PPS or medical chair) has been designed to perform in different modes of research on patients. This device operates in the angiography mode, with alternating up and down movements in 1.6 s cycles over a period of about 30 s. The tomography mode is used mainly for the imaging of the brain. It consists of turning the patient around an axis perfectly perpendicular to the beam plane. A dual-energy scan involves two rotations with one image recorded each turn at a different energy (Phys. Med. Biol. 45 (2000) L39). The first angiography imaging on patients was undertaken in January 2000 after successful pre-clinical tests on animals.

Dabin, Y.; Draperi, A.; Elleaume, H.; Charvet, A.-M.; Brochard, T.; Perez, M.; Nemoz, C.; Blattmann, G.; Renier, M.; Fournier, F.; Dupuy, J.-L.; Lemoine, B.; Bouhaniche, P.; Thomlinson, W.; Suortti, P.

2001-07-01

86

CDAWeb and SSCWeb: Expanding Correlative Sun-Earth-Connections Science Services in the New Era of IMAGE and Cluster  

NASA Astrophysics Data System (ADS)

The Coordinated Data Analysis [Workshop] Web service (CDAWeb) supports graphical and data retrieval access to a uniquely broad and still growing database of multi-mission Sun-Earth-Connections (SEC) data. SSCWeb serves satellite orbits and various multi-mission conjunctions queries. By May 2001, CDAWeb will be serving public data from all IMAGE instruments and Cluster Summary Parameters, as well as Cluster Prime Parameters to authorized Cluster science investigators. These systems make current data quickly accessible to a wide research community and immediately available in the context of simultaneous data from almost all other current space physics missions. These systems are first working prototypes for delivering the class of integrated, multi-mission data view essential to the programs like Living with a Star (LWS). These systems' databases, capabilities, and usage continue to grow. CDAWeb has served 150,000 separate plots and listings in the last year alone, SSCWeb 26,000 listings, query results and plots. CDAWeb now has over 1450 days (4 years) with data from more 100 data sets available for every day. Over the last year, CDAWeb has been extended to 350+ GBytes and added new datasets from Wind, Polar and IMP-8, as well as ongoing flows of data from many other missions. CDAWeb remains supported by three mirror sites (in Germany-MPE, England-RAL and Japan-ISAS) as well as by the primary site at Goddard. ASCII listing and file retrieval services have been extended to include compressed (gzip) and multiple-file combined (tar) "one-keystroke" retrievals. Supported by the NASA Office of Space Science, CDAWeb and SSCWeb are joint efforts of the NASA GSFC Space Physics Data Facility (SPDF) and the National Space Science Data Center (NSSDC). These services are only possible in turn by data flows from various project data facilities and the work of the instrument science teams on the many missions now supported.

McGuire, R. E.; Candey, R. M.; Fung, S. F.; Green, J. L.; Kessel, R. L.; Kovalick, T. J.

2001-05-01

87

Clinical and imaging heterogeneity of polymicrogyria: a study of 328 patients  

PubMed Central

Polymicrogyria is one of the most common malformations of cortical development and is associated with a variety of clinical sequelae including epilepsy, intellectual disability, motor dysfunction and speech disturbance. It has heterogeneous clinical manifestations and imaging patterns, yet large cohort data defining the clinical and imaging spectrum and the relative frequencies of each subtype are lacking. The aims of this study were to determine the types and relative frequencies of different polymicrogyria patterns, define the spectrum of their clinical and imaging features and assess for clinical/imaging correlations. We studied the imaging features of 328 patients referred from six centres, with detailed clinical data available for 183 patients. The ascertainment base was wide, including referral from paediatricians, geneticists and neurologists. The main patterns of polymicrogyria were perisylvian (61%), generalized (13%), frontal (5%) and parasagittal parieto-occipital (3%), and in 11% there was associated periventricular grey matter heterotopia. Each of the above patterns was further divided into subtypes based on distinguishing imaging characteristics. The remaining 7% were comprised of a number of rare patterns, many not described previously. The most common clinical sequelae were epileptic seizures (78%), global developmental delay (70%), spasticity (51%) and microcephaly (50%). Many patients presented with neurological or developmental abnormalities prior to the onset of epilepsy. Patients with more extensive patterns of polymicrogyria presented at an earlier age and with more severe sequelae than those with restricted or unilateral forms. The median age at presentation for the entire cohort was 4 months with 38% presenting in either the antenatal or neonatal periods. There were no significant differences between the prevalence of epilepsy for each polymicrogyria pattern, however patients with generalized and bilateral forms had a lower age at seizure onset. There was significant skewing towards males with a ratio of 3:2. This study expands our understanding of the spectrum of clinical and imaging features of polymicrogyria. Progression from describing imaging patterns to defining anatomoclinical syndromes will improve the accuracy of prognostic counselling and will aid identification of the aetiologies of polymicrogyria, including genetic causes.

Jansen, Anna; Pilz, Daniela T.; Stoodley, Neil; Marini, Carla; Dubeau, Francois; Malone, Jodie; Mitchell, L. Anne; Mandelstam, Simone; Scheffer, Ingrid E.; Berkovic, Samuel F.; Andermann, Frederick; Andermann, Eva; Guerrini, Renzo; Dobyns, William B.

2010-01-01

88

Efficacy and safety of ipilimumab in elderly patients with pretreated advanced melanoma treated at Italian centres through the expanded access programme  

PubMed Central

Background Elderly patients with metastatic melanoma have different disease characteristics and a poorer prognosis than younger patients. Data from clinical trials and expanded access programmes (EAPs) suggest ipilimumab confers a consistent survival benefit and has a similar safety profile across different age groups of patients with metastatic melanoma. Here we report the efficacy and safety of ipilimumab 3 mg/kg in elderly patients enrolled in an EAP in Italy. Methods Patients aged?>?70 years with pretreated melanoma received ipilimumab 3 mg/kg every 3 weeks for four doses through an EAP. Tumour response was evaluated at baseline and after completion of induction therapy using immune-related response criteria and patients were monitored throughout the treatment period for adverse events (AEs), including immune-related AEs. Results The immune-related disease control rate among 188 evaluable patients was 38%, including four patients with an immune-related complete response, 24 with an immune-related partial response and 44 with immune-related stable disease. Median progression-free survival (PFS) was 4.0 months and the 1- and 2-year PFS rates were 21% and 12%, respectively. Median overall survival (OS) was 8.9 months; 1- and 2-year OS rates were 38% and 22%, respectively. The safety profile of ipilimumab was consistent with that observed in the general population of the Italian EAP and treatment-related AEs generally resolved within a median of 2 weeks with treatment as per protocol-specific guidelines. Conclusions These results suggest ipilimumab is a feasible treatment option in elderly patients with metastatic melanoma. Ipilimumab treatment was generally well tolerated and resulted in clinical benefit and extended survival in elderly patients treated at centres in Italy.

2014-01-01

89

Imaging of the small bowel: Crohn's disease in paediatric patients  

PubMed Central

In more than 20% of all patients, the Crohn’s disease presents before the age of 18years. The diagnosis and management of Crohn’s disease in children has changed dramatically over the last decade, mainly due to increased awareness, availability of newer diagnostic modalities such as magnetic resonance imaging (MRI) and newer, more powerful treatments such as biologics. Imaging of the small bowel is needed for diagnosis, management, follow-up and also evaluation of the disease in terms of location, extent, activity and complications. We review all the methods (barium examinations, ultrasonography, computed tomography, MR, and computed tomography- positron emission tomography) commonly used for imaging the small bowel in paediatric patients with Crohn’s disease analyzing the advantages and disadvantages of each modality, with particular emphasis on MR imaging.

Casciani, Emanuele; De Vincentiis, Chiara; Polettini, Elisabetta; Masselli, Gabriele; Di Nardo, Giovanni; Civitelli, Fortunata; Cucchiara, Salvatore; Gualdi, Gian Franco

2014-01-01

90

Transmission and storage of medical images with patient information.  

PubMed

Digital watermarking is a technique of hiding specific identification data for copyright authentication. This technique is adapted here for interleaving patient information with medical images, to reduce storage and transmission overheads. The text data is encrypted before interleaving with images to ensure greater security. The graphical signals are interleaved with the image. Two types of error control-coding techniques are proposed to enhance reliability of transmission and storage of medical images interleaved with patient information. Transmission and storage scenarios are simulated with and without error control coding and a qualitative as well as quantitative interpretation of the reliability enhancement resulting from the use of various commonly used error control codes such as repetitive, and (7,4) Hamming code is provided. PMID:12791403

Acharya U, Rajendra; Subbanna Bhat, P; Kumar, Sathish; Min, Lim Choo

2003-07-01

91

Does a continuous local anaesthetic pain treatment after immediate tissue expander reconstruction in breast carcinoma patients more efficiently reduce acute postoperative pain - a prospective randomised study  

PubMed Central

Background Immediate breast reconstruction with an expander is a reasonable option for properly selected patients. After reconstruction, patients have severe postoperative pain, which responds poorly to opioids. Our aim was to evaluate if continuous wound infusion of a local anaesthetic into the surgical wound reduces postoperative pain, consumption of opioids and incidence of chronic pain compared to standard intravenous piritramide after primary breast reconstruction in breast carcinoma patients. Methods Altogether, 60 patients were enrolled in our study; one half in the group with wound infusion of a local anaesthetic, and the other half in the standard (piritramide) group. Parameters measured included: pain intensity (visual analogue scale), drug requirements, alertness, hospitalisation, side-effects and late complications. A p-value of?expander breast reconstruction, wound infusion of a local anaesthetic significantly reduces acute pain and enables reduced opioid consumption, resulting in less postoperative sedation and reduced need for antiemetic drugs. Wound infusion of a local anaesthetic reduces chronic pain.

2014-01-01

92

[Magnetic resonance imaging of the mediastinal vessels in pediatric patients].  

PubMed

The appearance of new and better magnetic resonance imaging (MRI) techniques have made the MRI a very important imaging method for the evaluation of thoracic vessels in pediatrics. The 3D angio-MRI using GD is capable of clearly demonstrating the morphology of the aorta and pulmonary vessels. The MRI may significantly reduce the number of angiographies needed and, in some patients, may even provide additional information to the angiography. PMID:17910864

Hernández, R J; Sáez, F

2007-01-01

93

Initial clinical experience with distal embolic protection using "Filtrap", a novel filter device with a self-expandable spiral basket in patients undergoing percutaneous coronary intervention.  

PubMed

We developed a new filter-type distal protection guide wire, Filtrap, that uses a polyurethane filter with 1834 100-?m micropores covering the distal half of a spindle-shaped spiral Ni-Ti basket. The basket is 5 mm in diameter, self-expandable, and is mounted at the distal end of the system. This study aimed to assess the usefulness and safety of Filtrap during percutaneous coronary intervention (PCI). Early angiographic and in-hospital outcomes were reviewed in 14 patients, including 9 acute coronary syndrome patients, treated with Filtrap during PCI. All lesions were located in native coronary arteries but one was located in a saphenous vein graft. The Filtrap was successfully delivered and deployed distal to the lesion in 13 of 14 patients (93%). All PCI procedures including stent implantation were successfully completed except for 2 AMI patients, who ended up with Thrombolysis in Myocardial Infarction (TIMI) 2 coronary flow. One of these 2 patients had a distal embolization which occurred after thrombectomy before Filtrap insertion. The mean time of device insertion was 9.4 ± 3.2 min. Five patients showed transient no-reflow that was completely restored immediately with removal of the device. Embolic debris was entrapped in 8 (62%) of these cases. All patients were free from in-hospital events except for one patient with a large anterior acute myocardial infarction who received an emergency surgery due to a free wall cardiac rupture. These results suggest that the Filtrap is a practical and safe device for embolic protection during PCI. PMID:24122493

Isshiki, Takaaki; Kozuma, Ken; Kyono, Hiroyuki; Suzuki, Nobuaki; Yokoyama, Naoyuki; Yamamoto, Yoshito

2011-01-01

94

Depression in adults with congenital heart disease-public health challenge in a rapidly expanding new patient population  

PubMed Central

There is a growing population of adults with congenital heart disease (CHD) due to improved survival beyond childhood. It has been suggested that adults with CHD may be at increased risk for mental health problems, particularly depression. The reported incidence of depression in CHD varies from 9% to 30%. This review examines the evidence for a higher depression rate in CHD vs general population. Possible explanations are offered from a variety of disease models, ranging from brain injury to the psychoanalytical approach. Risk factors for an abnormal emotional adjustment and depression include early exposure to stress from illness and medical interventions in infancy, separation from the parents during hospitalizations and brain organic syndromes. Later in life, patients often have to cope with physical limitations. Recent improvements in care may be protective. Current patients may benefit from an earlier age at first surgical intervention, fewer reoperations and inclusion to the mainstream schooling, among other factors. At this point, there is little systematic knowledge about evidence-based therapeutic interventions for depression in adults with CHD. Health care providers of patients with CHD should be aware of mental health challenges and may take a more proactive approach to identifying patients at risk for depression.

Pauliks, Linda B

2013-01-01

95

Expanded polytetrafluoroethylene membranes to wrap surfaces of circulatory support devices in patients undergoing bridge to heart transplantation  

Microsoft Academic Search

Objective: Because of a lack of donor hearts, an increasing number of patients with heart failure must now undergo bridge to cardiac transplantation with a mechanical circulatory support device. Moreover, support periods have become longer. As a result, pericardial adhesions may develop while the support device is implanted, increasing the risk of injury at resternotomy and bleeding after transplantation. Use

P. Leprince; M. Rahmati; N. Bonnet; V. Bors; A. Rama; Ph. Léger; I. Gandjbakhch; A. Pavie

2001-01-01

96

Patient dose and image quality from mega-voltage cone beam computed tomography imaging.  

PubMed

The evolution of ever more conformal radiation delivery techniques makes the subject of accurate localization of increasing importance in radiotherapy. Several systems can be utilized including kilo-voltage and mega-voltage cone-beam computed tomography (MV-CBCT), CT on rail or helical tomography. One of the attractive aspects of mega-voltage cone-beam CT is that it uses the therapy beam along with an electronic portal imaging device to image the patient prior to the delivery of treatment. However, the use of a photon beam energy in the mega-voltage range for volumetric imaging degrades the image quality and increases the patient radiation dose. To optimize image quality and patient dose in MV-CBCT imaging procedures, a series of dose measurements in cylindrical and anthropomorphic phantoms using an ionization chamber, radiographic films, and thermoluminescent dosimeters was performed. Furthermore, the dependence of the contrast to noise ratio and spatial resolution of the image upon the dose delivered for a 20-cm-diam cylindrical phantom was evaluated. Depending on the anatomical site and patient thickness, we found that the minimum dose deposited in the irradiated volume was 5-9 cGy and the maximum dose was between 9 and 17 cGy for our clinical MV-CBCT imaging protocols. Results also demonstrated that for high contrast areas such as bony anatomy, low doses are sufficient for image registration and visualization of the three-dimensional boundaries between soft tissue and bony structures. However, as the difference in tissue density decreased, the dose required to identify soft tissue boundaries increased. Finally, the dose delivered by MV-CBCT was simulated using a treatment planning system (TPS), thereby allowing the incorporation of MV-CBCT dose in the treatment planning process. The TPS-calculated doses agreed well with measurements for a wide range of imaging protocols. PMID:17388167

Gayou, Olivier; Parda, David S; Johnson, Mark; Miften, Moyed

2007-02-01

97

Diffusion tensor magnetic resonance imaging in patients with multiple sclerosis and its relationship with disability.  

PubMed

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system. Diffusion tensor magnetic resonance imaging (DTI) can yield important information on the in vivo pathological processes affecting water diffusion. The aim of this study was to quantitatively define water diffusion in normal-appearing white matter (NAWM) distant from the plaque, in the plaque, and around the plaque, and to investigate the correlation of these changes with clinical disability. Conventional MRI and DTI scans were conducted in 30 patients with MS and 15 healthy individuals. Fractional anisotropy maps and visible diffusion coefficients were created and integrated with T2-weighted images. Regions of interest (ROIs) were placed on the plaques on the same side, white matter around the plaques and NAWM on the opposite side. Only the white matter of healthy individuals in the control group, and FA and ADC values were obtained for comparison. The highest FA and lowest ADC were detected in the control group at the periventricular region, cerebellar peduncle and at all ROIs irrespective of location. There was a significant difference in comparison to the control group at all ROIs in patients with MS (p < 0.001 for all comparisons). No significant correlation between diffusion parameters and expanded disability state scale (EDSS) scores was found in patients with MS. DTI may provide more accurate information on the damage due to the illness, compared to T2A sequences, but this damage may not be correlated with the clinical disability measured by EDSS score. PMID:23859160

Temel, S; Kekliko?lu, H D; Kekli?ko?lu, H D; Vural, G; Deniz, O; Ercan, K

2013-02-01

98

A study of multiple sclerosis patients with magnetic resonance spectroscopic imaging.  

PubMed

Eleven patients with clinically definite MS and three healthy controls were investigated by magnetic resonance spectroscopic imaging. The data sets were analysed for all voxels containing white matter only. We classify these voxels in healthy controls as normal white matter (NWM), and in MS patients as normal-appearing white matter unaffected by MS lesions (NAWM) or white matter affected by MS lesions. The spectra belonging to the voxels were analysed for content of cholines, creatines and N-acetylaspartate (NAA), and compared as a group. It was found that lesions differ from white matter in chemical composition and, moreover, that normal-appearing white matter differs from healthy white matter. Specifically, levels of NAA are lower in patients. There seems to be a linear relation between the composition of white matter and the expanded disability status scale value for the patient. The presence of lactate could not be established, and no unambiguous differences were found between patients with relapsing-remitting and relapsing-progressive disease. PMID:9345466

Peters, A R; Geelen, J A; den Boer, J A; Prevo, R L; Minderhoud, J M; 's Gravenmade, E J

1995-04-01

99

76 Expanding the role of cardiac care unit nurses to reduce time to treatment for patients requiring primary angioplasty  

Microsoft Academic Search

IntroductionIn Brighton, UK, 24-h Primary Angioplasty has been used for the treatment of ST segment elevation myocardial infarction (STEMI) since October 2008, with local patients being admitted via the Accident and Emergency (A&E) department. With the publication of the National Infarct Angioplasty project report (DH 2008) it was evident that direct admission into the cardiac catheter lab from the ambulance

S Young; G Pretsell; A Gibbins; G Dixon; A de Belder

2011-01-01

100

Expanding the horizons of histoplasmosis: disseminated histoplasmosis in a renal transplant patient after a trip to Bangladesh.  

PubMed

Histoplasmosis is recognized to occur in the Ohio and Mississippi River Valleys of the United States, but less widely appreciated is its worldwide distribution. We report a case of disseminated histoplasmosis with disease involving skin, lungs, and epiglottis in a renal transplant patient 6 months after a trip to Bangladesh, to highlight the potential risk of acquisition of this infection in the Indian subcontinent. PMID:19878490

Rappo, U; Beitler, J R; Faulhaber, J R; Firoz, B; Henning, J S; Thomas, K M; Maslow, M; Goldfarb, D S; Horowitz, H W

2010-04-01

101

Clinical experience with ipilimumab 10 mg/kg in patients with melanoma treated at Italian centres as part of a European expanded access programme  

PubMed Central

Background Patients with advanced melanoma are faced with a poor prognosis and, until recently, limited treatment options. Ipilimumab, a novel immunotherapy that blocks cytotoxic T-lymphocyte-associated antigen-4, was the first agent to improve survival of patients with advanced melanoma in a randomised, controlled phase 3 trial. We used data from an expanded access programme (EAP) at Italian centres to evaluate the clinical activity and safety profile of ipilimumab 10 mg/kg in patients with advanced melanoma in a setting more similar to that of daily practice. Methods Data were collected from patients enrolled in an ipilimumab EAP across eight participating Italian centres. As per the EAP protocol, patients had life-threatening, unresectable stage III/IV melanoma, had failed or did not tolerate previous treatments and had no other therapeutic option available. Treatment comprised ipilimumab 10 mg/kg every 3 weeks for a total of four doses. If physicians believed patients would continue to derive benefit from ipilimumab treatment, maintenance therapy with ipilimumab 10 mg/kg was provided every 12 weeks. Tumour responses were assessed every 12 weeks using modified World Health Organization criteria and safety continuously monitored. Results Seventy-four pretreated patients with advanced melanoma were treated with ipilimumab 10 mg/kg. Of these, 9 (13.0%) had an objective response, comprising 3 patients with a complete response and 6 with a partial response. Median overall survival was 7.0 months (95% confidence interval, 5.3–8.7) and 16.6% of patients were alive after 3 years. Forty-five patients (60.8%) reported treatment-related adverse events of any grade, which were most commonly low-grade pruritus, pain, fever and diarrhoea. Grade 3 or 4 treatment-related AEs were reported in 8 patients (10.8%). Conclusions The clinical activity and safety profile of ipilimumab 10 mg/kg in the EAP was similar to that seen in previous clinical trials of ipilimumab in pretreated patient populations.

2013-01-01

102

Patient-centered imaging: shared decision making for cardiac imaging procedures with exposure to ionizing radiation.  

PubMed

The current paper details the recommendations arising from an NIH-NHLBI/NCI-sponsored symposium held in November 2012, aiming to identify key components of a radiation accountability framework fostering patient-centered imaging and shared decision-making in cardiac imaging. Symposium participants, working in 3 tracks, identified key components of a framework to target critical radiation safety issues for the patient, the laboratory, and the larger population of patients with known or suspected cardiovascular disease. The use of ionizing radiation during an imaging procedure should be disclosed to all patients by the ordering provider at the time of ordering, and reinforced by the performing provider team. An imaging protocol with effective dose ?3 mSv is considered very low risk, not warranting extensive discussion or written informed consent. However, a protocol effective dose >20 mSv was proposed as a level requiring particular attention in terms of shared decision-making and either formal discussion or written informed consent. Laboratory reporting of radiation dosimetry is a critical component of creating a quality laboratory fostering a patient-centered environment with transparent procedural methodology. Efforts should be directed to avoiding testing involving radiation, in patients with inappropriate indications. Standardized reporting and diagnostic reference levels for computed tomography and nuclear cardiology are important for the goal of public reporting of laboratory radiation dose levels in conjunction with diagnostic performance. The development of cardiac imaging technologies revolutionized cardiology practice by allowing routine, noninvasive assessment of myocardial perfusion and anatomy. It is now incumbent upon the imaging community to create an accountability framework to safely drive appropriate imaging utilization. PMID:24530677

Einstein, Andrew J; Berman, Daniel S; Min, James K; Hendel, Robert C; Gerber, Thomas C; Carr, J Jeffrey; Cerqueira, Manuel D; Cullom, S James; DeKemp, Robert; Dickert, Neal W; Dorbala, Sharmila; Fazel, Reza; Garcia, Ernest V; Gibbons, Raymond J; Halliburton, Sandra S; Hausleiter, Jörg; Heller, Gary V; Jerome, Scott; Lesser, John R; Raff, Gilbert L; Tilkemeier, Peter; Williams, Kim A; Shaw, Leslee J

2014-04-22

103

3D interfractional patient position verification using 2D-3D registration of orthogonal images  

SciTech Connect

Reproducible positioning of the patient during fractionated external beam radiation therapy is imperative to ensure that the delivered dose distribution matches the planned one. In this paper, we expand on a 2D-3D image registration method to verify a patient's setup in three dimensions (rotations and translations) using orthogonal portal images and megavoltage digitally reconstructed radiographs (MDRRs) derived from CT data. The accuracy of 2D-3D registration was improved by employing additional image preprocessing steps and a parabolic fit to interpolate the parameter space of the cost function utilized for registration. Using a humanoid phantom, precision for registration of three-dimensional translations was found to be better than 0.5 mm (1 s.d.) for any axis when no rotations were present. Three-dimensional rotations about any axis were registered with a precision of better than 0.2 deg. (1 s.d.) when no translations were present. Combined rotations and translations of up to 4 deg. and 15 mm were registered with 0.4 deg. and 0.7 mm accuracy for each axis. The influence of setup translations on registration of rotations and vice versa was also investigated and mostly agrees with a simple geometric model. Additionally, the dependence of registration accuracy on three cost functions, angular spacing between MDRRs, pixel size, and field-of-view, was examined. Best results were achieved by mutual information using 0.5 deg. angular spacing and a 10x10 cm{sup 2} field-of-view with 140x140 pixels. Approximating patient motion as rigid transformation, the registration method is applied to two treatment plans and the patients' setup errors are determined. Their magnitude was found to be {<=}6.1 mm and {<=}2.7 deg. for any axis in all of the six fractions measured for each treatment plan.

Jans, H.-S.; Syme, A.M.; Rathee, S.; Fallone, B.G. [Department of Medical Physics, Cross Cancer Institute, Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G IZ2 (Canada); Department of Medical Physics, Cross Cancer Institute, Department of Oncology, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G IZ2 (Canada); Department of Medical Physics, Cross Cancer Institute, Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G IZ2 (Canada)

2006-05-15

104

Dimensions of neutropenia in adult cancer patients: expanding conceptualizations beyond the numerical value of the absolute neutrophil count.  

PubMed

Neutropenia is a common and dangerous toxicity of cancer therapy that profoundly affects patients' lives. Neutropenia is typically defined by the numerical value of the absolute neutrophil count. However, considering neutropenia exclusively as the numerical value of the absolute neutrophil count limits its conceptualizations to physiologically related aspects, minimizes its complexities, and neglects dimensions of human response and the patient experience. This article offers a dimensional analysis of neutropenia derived from 42 research and clinical articles. Schatzman's dimensional analysis methods were applied to the literature to identify aspects of this phenomenon lying beyond its numerical boundaries. Dimensions of neutropenia that emerged were sorted into categories of perspective, context, conditions, processes, and consequences. The presence of the same dimension in more than 1 category and the circuitous relationships among categories begin to explicate the complexity and gravity of neutropenia. Articulation of these dimensions is necessary to assemble the beginnings of a theoretical understanding of neutropenia, which is crucial for the development and application of knowledge to research and practice. Limitations evident in the literature illuminate the urgent need for research into the psychosocial as well as physiologic dimensions of neutropenia. PMID:15292722

Crighton, Margaret H

2004-01-01

105

The role of functional imaging in the tumor patient.  

PubMed

Functional imaging studies complement structural magnetic resonance imaging (MRI) in the assessment of patients with brain tumor-associated focal epilepsy. (11)C-Methionine (MET) and (18) F-fluoro-ethyl-L-tyrosine (FET) are amino acid analogues that highlight metabolically active areas in positron emission tomography (PET). Ictal single photon emission computed tomography (SPECT) can provide information about perilesional areas of seizure onset and early propagation. Functional MRI (fMRI) and diffusion tensor imaging (DTI) allow noninvasive identification of potentially eloquent motor, sensory, and language cortical areas and pathways with an accuracy of 10-15 mm compared to electrocortical stimulation (ECS). Repetitive navigated transcranial magnetic stimulation (TMS) allows even more precise noninvasive delineation of primary motor cortex. Information from functional imaging studies helps in the planning of brain tumor biopsies, resections, and the planning of intracranial video-electroencephalography (EEG) studies. PMID:24328872

Wehner, Tim

2013-12-01

106

Radiation myelopathy in over-irradiated patients: MR imaging findings.  

PubMed

The objective of this work is to report the MRI findings in patients with radiation myelopathy due to accidental local over-irradiation syndrome. Eight patients (seven males and one female) were suffering from over-irradiation syndrome as a result of treatments from a malfunctioning linear electron accelerator. The mean accidental estimated dose was 136 Gy delivered to the "open-neck" (seven cases) and to the thoracic wall (one case), during a mean of 5.4 sessions (range 1-9 sessions). Paresthesia and weakness in the upper extremities were the earliest symptoms (87.5 %), with evolution to paralysis in all patients. No patient is alive (mean survival time 64 days). In all cases MRI was negative for neurologic lesions in the acute phase ( < 90 days from irradiation; Radiation Therapy Oncology Group scoring system). Late signs of radiation myelitis manifested as high-intensity signals on T2-weighted images in three patients, and as Gd-DTPA enhancement of T1-weighted images in one case. Autopsies performed on four patients who died in acute phase showed morphologic alterations in white matter: edema in 75 %, and necrosis and glial reaction as well as obliterative vasculitis in all cases. In cases of over-irradiation, MRI may be normal in acute phase even if the patients have severe neurologic deficit, as positive MRI findings appear only in delayed radiation myelitis. PMID:9087365

Alfonso, E R; De Gregorio, M A; Mateo, P; Escó, R; Bascón, N; Morales, F; Bellosta, R; López, P; Gimeno, M; Roca, M; Villavieja, J L

1997-01-01

107

Cardiac magnetic resonance imaging of a patient with an magnetic resonance imaging conditional permanent pacemaker  

PubMed Central

Cardiac magnetic resonance imaging (MRI) is increasingly used as the optimum modality for cardiac imaging. An aging population and rising numbers of patients with permanent pacemakers means many such individuals may require cardiac MRI scanning in the future. Whilst the presence of a permanent pacemaker is historically regarded as a contra-indication to MRI scanning, pacemaker systems have been developed to limit any associated risks. No reports have been published regarding the use of such devices with cardiac MRI in a clinical setting. We present the safe, successful cardiac MRI scan of a patient with an MRI-conditional permanent pacing system.

Hogarth, Andrew J.; Artis, Nigel J.; Sivananthan, U. Mohan; Pepper, Chris B.

2011-01-01

108

Bardet-Biedl Syndrome in an African-American patient: should the diagnostic criteria be expanded to include hydrometrocolpos?  

PubMed

Bardet-Biedl Syndrome (BBS) is a multisystemic disorder diagnosed on the basis of a combination of primary and secondary clinical features that include retinal dystrophy, obesity, polydactyly, cognitive dysfunction, and renal malformations. We report a unique case of BBS in a 13-year old girl of African-American descent who presented with retinitis pigmentosa, obesity, polydactyly, learning disabilities, precocious puberty, hypertension, renal cysts, and Hirschprung disease. Further evaluation revealed a history of precocious puberty, which is antithetical to the common manifestations of BBS, while neuroimaging was suggestive of periventricular leukomalacia and neuro-electrophysiologic studies revealed diffuse cerebral disturbance, which may contribute to her neurological abnormalities. The patient was also diagnosed with hydrometrocolpos, a finding typical of McKusick-Kaufman Syndrome (MKKS) but infrequent in other disorders. This observation, together with recent findings in some mouse models of BBS, raises the question of whether hydrometrocolpos should be considered as an additional diagnostic criterion for BBS to be used in females in parallel to the criterion of hypogonadism in males, thereby improving diagnostic sensitivity. PMID:17558852

Toma, Hassanain S; Tan, Perciliz L; McKusick, Victor A; Katsanis, Nicholas; Adams, N A

2007-06-01

109

MR enterography imaging of Crohn's disease in pediatric patients  

PubMed Central

Summary Background Crohn disease (CD) is a chronic inflammatory process of gastrointestinal tract, which frequently affects children. Recent advances in Magnetic Resonance Imaging (MRI) technique have made small bowel imaging possible, what is extremely useful in pediatrics. The purpose of this article is to describe the characteristic MR enterography findings and to present the advantages of this modality in pediatric patients. Material/Methods A group of 40 patients referred from the Department of Pediatric Gastroenterology and Nutrition, Medical University of Warsaw was included in the analysis. The patients’ age ranged from 7 to 18 years (mean age 14 years). Among the study participants, 28 patients were diagnosed with CD, whereas 12 patients had a history of ulcerative colitis or were strongly suspected of CD based on clinical data. The examinations were performed on GE Signa HD 1,5 T system. Small bowel distention was achieved by oral administration of 600–1000 ml of hyperosmotic solution of polyetylenglycol (PEG). Prior to the examination, 20–40 mg of a spasmolytic drug, hioscine-N-butylobromide (Buscolysin®), was administrated to reduce peristaltic movements. Results The abnormal small bowel segments were found in 21 patients and the features of colonic disease were detected in 5 patients. In 2 patients the lesions involved both small and large bowel. In 16 subjects mural changes were not found. Among studied patients, following signs of small bowel inflammation were fund: bowel wall thickening (n=21), submucosal edema (n=8), segment wall hyperenhancement (n=18), deep ulceration (n=6), fistula (n=3), stenosis (n=7), mesenteric signs such as hyperemia (n=9), fibrofatty proliferation (n=8) and lymphadenopathy (n=28). Conclusions MR enterography is an excellent examination, which provides an accurate information about severity and activity of and complications related to CD. It is especially valuable in children, because of lack of the negative consequences of repeated exposure to ionizing radiation.

Podgorska, Joanna; Pacho, Ryszard; Albrecht, Piotr

2014-01-01

110

THE EXPANDING NEBULAR REMNANT OF THE RECURRENT NOVA RS OPHIUCHI (2006). II. MODELING OF COMBINED HUBBLE SPACE TELESCOPE IMAGING AND GROUND-BASED SPECTROSCOPY  

SciTech Connect

We report Hubble Space Telescope (HST) imaging, obtained 155 and 449 days after the 2006 outburst of the recurrent nova RS Ophiuchi, together with ground-based spectroscopic observations, obtained from the Observatorio Astronomico Nacional en San Pedro Martir, Baja California, Mexico and at the Observatorio AstrofIsico Guillermo Haro, at Cananea, Sonora, Mexico. The observations at the first epoch were used as inputs to model the geometry and kinematic structure of the evolving RS Oph nebular remnant. We find that the modeled remnant comprises two distinct co-aligned bipolar components; a low-velocity, high-density innermost (hour glass) region and a more extended, high-velocity (dumbbell) structure. This overall structure is in agreement with that deduced from radio observations and optical interferometry at earlier epochs. We find that the asymmetry observed in the west lobe is an instrumental effect caused by the profile of the HST filter and hence demonstrate that this lobe is approaching the observer. We then conclude that the system has an inclination to the line of sight of 39{sup +10}{sub -10}. This is in agreement with the inclination of the binary orbit and lends support to the proposal that this morphology is due to the interaction of the outburst ejecta with either an accretion disk around the central white dwarf and/or a pre-existing red giant wind that is significantly denser in the equatorial regions of the binary than at the poles. The second epoch HST observation was also modeled. However, as no spectra were taken at this epoch, it is more difficult to constrain any model. Nevertheless, we demonstrate that between the two HST epochs the outer dumbbell structure seems to have expanded linearly. For the central (hour glass) region, there may be evidence of deceleration, but it is harder to draw firm conclusions in this case.

Ribeiro, V. A. R. M.; Bode, M. F.; Darnley, M. J., E-mail: var@astro.livjm.ac.u, E-mail: mfb@astro.livjm.ac.u, E-mail: mjd@astro.livjm.ac.u [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, Wirral, CH41 1LD (United Kingdom)

2009-10-01

111

Clonal B cells in patients with hepatitis C virus-associated mixed cryoglobulinemia contain an expanded anergic CD21low B-cell subset  

PubMed Central

Hepatitis C virus (HCV) is associated with the B-cell lymphoproliferative disorders mixed cryoglobulinemia (MC) and non-Hodgkin lymphoma. We have previously reported that HCV+MC+ patients have clonal expansions of hypermutated, rheumatoid factor–bearing marginal zone-like IgM+CD27+ peripheral B cells using the VH1-69 gene. Here we coupled transcriptional profiling with immunophenotypic and functional studies to ascertain these cells' role in MC pathogenesis. Despite their fundamental role in MC disease, these B cells have overall transcriptional features of anergy and apoptosis instead of neoplastic transformation. Highly up-regulated genes include SOX5, CD11C, galectin-1, and FGR, similar to a previously described FCRL4+ memory B-cell subset and to an “exhausted,” anergic CD21low memory B-cell subset in HIV+ patients. Moreover, HCV+MC+ patients' clonal peripheral B cells are enriched with CD21low, CD11c+, FCRL4high, IL-4Rlow memory B cells. In contrast to the functional, rheumatoid factor–secreting CD27+CD21high subset, the CD27+CD21low subpopulation exhibits decreased calcium mobilization and does not efficiently differentiate into rheumatoid factor–secreting plasmablasts, suggesting that a large proportion of HCV+MC+ patients' clonally expanded peripheral B cells is prone to anergy and/or apoptosis. Down-regulation of multiple activation pathways may represent a homeostatic mechanism attenuating otherwise uncontrolled stimulation of circulating HCV-containing immune complexes. This study was registered at www.clinicaltrials.gov as #NCT00435201.

Charles, Edgar D.; Brunetti, Claudia; Marukian, Svetlana; Ritola, Kimberly D.; Talal, Andrew H.; Marks, Kristen; Jacobson, Ira M.; Rice, Charles M.

2011-01-01

112

Effect of Patient Centering on Patient Dose and Image Noise in Chest CT.  

PubMed

OBJECTIVE. The objective of our study was to evaluate the effect of vertical centering on dose and image noise in chest MDCT of different-sized patients using anthropomorphic phantoms and retrospectively studying examinations of clinical patients. MATERIALS AND METHODS. Three different anthropomorphic phantoms were scanned using different vertical centering (offset ± 6 cm) and were assessed with radiation dose-monitoring software. The effect of vertical positioning on the radiation dose was studied using the volume CT dose index, dose-length product, and size-specific dose estimates for different-sized phantoms. Image noise was determined from CT number histograms. Vertical positioning for chest CT examinations of 112 patients ranging from neonates to adults were retrospectively assessed. RESULTS. Radiation doses were highest when using the posteroanterior scout image for automatic exposure control (AEC) and when phantoms were set in the lowest table position, and radiation doses were lowest when phantoms were set in the uppermost table position. For the adult phantom, relative doses increased by 38% in the lowest table position and decreased by 23% in the highest table position. Similarly, doses for pediatric 5-year-old and newborn phantoms were 21% and 12% higher in the lowest table position and 12% and 8% lower in the highest table position, respectively. The effect decreased when a lateral scout image was used for AEC. The relative noise was lowest when the phantoms were properly centered and increased with vertical offset. In clinical patients, we observed offset with a median value varying from 25 to 35 mm below the isocenter. CONCLUSION. Regardless of patient size, most patients in this study were positioned too low, which negatively affected both patient dose and image noise. Miscentering was more pronounced in smaller pediatric patients. PMID:24951205

Kaasalainen, Touko; Palmu, Kirsi; Reijonen, Vappu; Kortesniemi, Mika

2014-07-01

113

A Case of Aorto-Bronchial Fistula After Insertion of Left Main Bronchial Self-Expanding Metallic Stent in a Patient with Recurrent Esophageal Cancer  

SciTech Connect

We report a case of aorto-bronchial fistula (ABF) caused by a self-expanding metallic stent (EMS) 51 days after insertion into the left main bronchus. The patient presented with left main bronchial stenosis caused by post-operative local recurrence of esophageal cancer. Post-operative radio therapy totaling 40 Gy and post-recurrence radiotherapy totaling 34 Gy were administered, with daily fractions of 2 Gy. Stenosis of the left main bronchus improved slightly, and was followed with insertion of EMS to prevent re-stenosis. The patient experienced massive hemoptysis for 3 days before sudden death. Autopsy revealed the EMS edge perforating the descending aortic lumen. Tumor infiltration and bacterial infection were observed on the wall of the left bronchus, and atherosclerosis was present on the aortic wall around the fistula. It should be noted that the left main bronchus was at considerable risk of ABF after insertion of EMS for malignant stenosis, and prophylactic stent insertion into the bronchus without imperative need must be avoided.

Onishi, Hiroshi, E-mail: honishi@res.yamanashi-med.ac.jp; Kuriyama, Kengo; Komiyama, Takafumi; Tanaka, Shiho; Marino, Kan; Tsukamoto, Tatsuaki; Araki, Tsutomu [Yamanashi Medical University, Department of Radiation Oncology (Japan)

2004-09-15

114

Using a patient image archive to diagnose retinopathy  

SciTech Connect

Diabetes has become an epidemic that is expected to impact 365 million people worldwide by 2025. Consequently, diabetic retinopathy is the leading cause of blindness in the industrialized world today. If detected early, treatments can preserve vision and significantly reduce debilitating blindness. Through this research we are developing and testing a method for automating the diagnosis of retinopathy in a screening environment using a patient archive and digital fundus imagery. We present an overview of our content-based image retrieval (CBIR) approach and provide performance results for a dataset of 98 images from a study in Canada when compared to an archive of 1,355 patients from a study in the Netherlands. An aggregate performance of 89% correct diagnosis is achieved, demonstrating the potential of automated, web-based diagnosis for a broad range of imagery collected under different conditions and with different cameras.

Tobin Jr, Kenneth William [ORNL; Abramoff, M.D. [University of Iowa; Chaum, Edward [University of Tennessee, Knoxville (UTK); Giancardo, Luca [ORNL; Govindaswamy, Priya [Oak Ridge National Laboratory (ORNL); Karnowski, Thomas Paul [ORNL; Tennant, M [University of Alberta; Swainson, Stephen [University of Alberta

2008-01-01

115

Expanding septum pellucidum cyst due to a traumatic ventriculoperitoneal shunt  

Microsoft Academic Search

A rare complication of a ventriculoperitoneal (VP) shunt is reported. Serial imaging studies demonstrated the formation of\\u000a an expanding septum pellucidum cyst after an indwelling shunt tube penetrated the wall of the septum pellucidum. This complication\\u000a should be borne in mind if patients have symptoms of intermittent obstructive hydrocephalus or related to pressure effects\\u000a from the septum pellucidum after VP

C. J. Chen

1999-01-01

116

IR imaging of blood circulation of patients with vascular disease  

NASA Astrophysics Data System (ADS)

We conducted a preliminary IR imaging study of blood circulation in patients with peripheral vascular diseases. Abnormal blood flow is common in older adults, especially those with elevated blood lipids, diabetes, hypertension, and a history of smoking. All of these conditions have a high prevalence in our population, often with more than one condition in the same individual. The differences in blood flow is revealed by temperature differences in areas of the extremities as well as other regions of the body. However, what is needed is an imaging technique that is relatively inexpensive and can reveal the blood flow in real time. The IR imaging can show detailed venous system and small tempearture changes associated with blood flow. Six patients with vascular diseases were tested in a clinic set up. Their legs and feet were imaged. We observed large temperature differences (cooling of more than 10° C) at the foot, especially toes. More valuable information were obtained from the temperature distribution maps. IR thermography is potentially a very valuable tool for medical application, especially for vascular diseases.

Wang, Hsin; Wade, Dwight R., Jr.; Kam, Jack

2004-04-01

117

Evaluation of cutaneous body image dissatisfaction in the dermatology patient.  

PubMed

Cutaneous body image (CBI), defined as the individual's mental representation of his or her skin, hair, and nails, is an important clinical factor in dermatologic disorders and often the primary consideration in deciding whether to proceed with cosmetic procedures or institute treatment in some skin disorders such as acne. CBI is a highly subjective construct that can be significantly confounded by cultural, psychosocial, and psychiatric factors. Assessment of CBI in the dermatology patient is best accomplished using a biopsychosocial model that involves (1) evaluation of concerns about the appearance of the skin, hair, and nails, (2) assessment of comorbid body image pathologies, especially body dysmorphic disorder, and (3) assessment of other psychiatric comorbidities such as major depressive disorder that can confound the presentation of the CBI complaint. Depending on the psychiatric comobidities, an assessment of suicide risk may have to be done, and if necessary, a referral made to a mental health professional. The clinician should consider the patient's developmental stage (eg, body image concerns are likely to be much greater in the adolescent patient independent of his or her dermatologic disorder) and sociocultural background (eg, a desire for lighter skin in some ethnic groups), factors that can also have a major effect on CBI. PMID:23245977

Gupta, Madhulika A; Gupta, Aditya K

2013-01-01

118

Magnetic resonance brain imaging in patients with acute stroke: feasibility and patient related difficulties  

PubMed Central

Objectives: To assess organisational and patient specific limitations and safety of magnetic resonance imaging (MRI) as the first line investigation for hospital admitted stroke patients. Methods: Consecutive patients admitted with acute stroke were assessed and an attempt was made to perform MRI in all patients. Oxygen saturation and interventions required during scanning were recorded. Results: Among 136 patients recruited over 34 weeks, 85 (62%) underwent MRI. The patients' medical instability (15 of the 53 not scanned), contraindications to MRI (six of the 53 not scanned), and rapid symptom resolution (10 of the 53 not scanned) were the main reasons for not performing MRI. Of the 85 patients who underwent MRI, 26 required physical intervention, 17 did not complete scanning, and 11 of the 61 who had successful oxygen saturation monitoring were hypoxic during MRI. Organisational limitations accounted for only 13% of failures to scan. Conclusions: Up to 85% of hospital admitted acute stroke patients could have MRI as first line imaging investigation, but medical instability is the major limitation. Hypoxia is frequent in MRI. Patients should be monitored carefully, possibly by an experienced clinician, during scanning.

Hand, P; Wardlaw, J; Rowat, A; Haisma, J; Lindley, R; Dennis, M

2005-01-01

119

Estimated Radiation Exposure from Medical Imaging in Hemodialysis Patients  

PubMed Central

Radiation exposure accompanying medical imaging associates with cancer risk. Patients with recurrent or chronic diseases may be especially at risk, because they may undergo more of these procedures. The aim of this study was to assess the individual cumulative effective doses (CEDs), which quantify radiation from medical imaging procedures, in a cohort of 106 hemodialysis patients during a median follow-up of 3 years. We retrospectively calculated individual radiation exposures by collecting the number and type of radiologic procedures from hospital records. We also estimated organ doses for computed tomography procedures. The mean and median annual CEDs were 21.9 and 11.7 mSv per patient-year, respectively. The mean and median total CEDs per patient during the study period were 57.7 and 27.3 mSv, respectively. By radiation dose group, we classified 22 patients as low (<3 mSv/yr), 51 as moderate (3 to <20 mSv/yr), 22 as high (20 to <50 mSv/yr), and 11 as very high (?50 mSv/yr). Seventeen patients had a total CED >100 mSv, a value associated with a substantial increase in risk for cancer- mortality. Of the total CED,s 76% was a result of CT scanning. The annual CED significantly associated with age and transplant waitlist status. In summary, this study shows that a significant fraction of surviving hemodialysis patients during a 3-year period receives estimated radiation doses that may put them at an increased risk for cancer.

De Mauri, Andreana; Chiarinotti, Doriana; Matheoud, Roberta; Carriero, Alessandro; De Leo, Martino

2011-01-01

120

Achieving success with the silicone expander for overacting superior obliques.  

PubMed Central

PURPOSE: To report the results of and complications with silicone expander surgery for the overacting superior oblique. METHODS: A total of 26 patients with bilateral overaction of the superior oblique and A-pattern strabismus and 5 patients with unilateral overacting superior oblique secondary to inferior oblique palsy were treated with a 7 mm silicone expander. Care was taken not to enter the sub-Tenon's space. RESULTS: The group that underwent bilateral superior oblique surgery had an average preoperative pattern of 37.42 diopters (D) and an average correction of 35.37 D. Three patients had a severe unilateral postoperative inflammatory incident that was successfully treated with oral and topical corticosteroids. One of these patient developed Brown's syndrome. Another patient, who had no postoperative inflammatory incident, also developed Brown's syndrome. In these 4 patients, the sub-Tenon's space was inadvertently entered during surgery. CONCLUSION: The silicone expander surgery has a very high success rate in treating the A-pattern associated with the bilateral overacting superior oblique. This procedure also works well for the unilateral superior oblique that overacts owing to an inferior oblique palsy. No cyclotorsion symptoms occurred after this surgery. However, 4 patients had complications because the sub-Tenon's space was exposed during surgery. With this procedure, there is a learning curve to obtain the skill not to enter the sub-Tenon's space. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6

Pollard, Z F; Greenberg, M

1999-01-01

121

Automatic segmentation of MR brain images in multiple sclerosis patients  

NASA Astrophysics Data System (ADS)

A totally automatic scheme for segmenting brain from extracranial tissues and to classify all intracranial voxels as CSF, gray matter (GM), white matter (WM), or abnormality such as multiple sclerosis (MS) lesions is presented in this paper. It is observed that in MR head images, if a tissue's intensity values are normalized, its relationship to the other tissues is essentially constant for a given type of image. Based on this approach, the subcutaneous fat surrounding the head is normalized to classify other tissues. Spatially registered 3 mm MR head image slices of T1 weighted, fast spin echo [dual echo T2 weighted and proton density (PD) weighted images] and fast fluid attenuated inversion recovery (FLAIR) sequences are used for segmentation. Subcutaneous fat surrounding the skull was identified based on intensity thresholding from T1 weighted images. A multiparametric space map was developed for CSF, GM and WM by normalizing each tissue with respect to the mean value of corresponding subcutaneous fat on each pulse sequence. To reduce the low frequency noise without blurring the fine morphological high frequency details an anisotropic diffusion filter was applied to all images before segmentation. An initial slice by slice classification was followed by morphological operations to delete any brides connecting extracranial segments. Finally 3-dimensional region growing of the segmented brain extracts GM, WM and pathology. The algorithm was tested on sequential scans of 10 patients with MS lesions. For well registered sequences, tissues and pathology have been accurately classified. This procedure does not require user input or image training data sets, and shows promise for automatic classification of brain and pathology.

Avula, Ramesh T. V.; Erickson, Bradley J.

1996-04-01

122

Cardiac magnetic resonance imaging in patients with Fabry's disease.  

PubMed

Fabry's disease (FD) is a rare hereditary disorder caused by the loss of alpha galactosidase A activity leading to accumulation of glycosphingolipids in various organs including hypertrophy of the heart. Most reports on cardiac involvement in FD focus on the left ventricular hypertrophy (LVH) and its relation to diastolic function. However, recent studies demonstrated large subset of patients with FD and right ventricle (RV) hypertophy. The accurate depiction of RV volumes, function and mass is possible with cardiovascular magnetic resonance (CMR). The CMR study can be also used to identify typically localised regions of intramyocardial fibrosis (infero-lateral segments of the LV), which have been shown to be a marker of inefficacious response to enzyme replacement therapy. We present series of 8 patients with genetically confirmed FD who underwent CMR study. We demonstrated a typical concentric and diffuse pattern of LVH with RV involvement in patients with the most severe LVH without significant impact on RV function and volumes. We showed that myocardial fibrosis can be observed not only in LV but also in RV. In 2 patients FD coexisted with symptomatic coronary artery disease with evidence of subendocardial myocardial fibrosis typical for ischaemic origin in one patient. The CMR confirmation of the presence of FD in one patient at an early stage of the disease, before the onset of advanced hypertrophy or failure of other organs, supports the value of this imaging technique in differential diagnosis of concentric and diffuse LVH. PMID:20730727

Ma?ek, Lukasz A; Chojnowska, Lidia; Spiewak, Mateusz; K?opotowski, Mariusz; Mi?ko, Jolanta; Petryka, Joanna; Mi?osz, Barbara; Ruzy??o, Witold

2010-08-01

123

Cerebella segmentation on MR images of pediatric patients with medulloblastoma  

NASA Astrophysics Data System (ADS)

In this study, an automated method has been developed to identify the cerebellum from T1-weighted MR brain images of patients with medulloblastoma. A new objective function that is similar to Gibbs free energy in classic physics was defined; and the brain structure delineation was viewed as a process of minimizing Gibbs free energy. We used a rigid-body registration and an active contour (snake) method to minimize the Gibbs free energy in this study. The method was applied to 20 patient data sets to generate cerebellum images and volumetric results. The generated cerebellum images were compared with two manually drawn results. Strong correlations were found between the automatically and manually generated volumetric results, the correlation coefficients with each of manual results were 0.971 and 0.974, respectively. The average Jaccard similarities with each of two manual results were 0.89 and 0.88, respectively. The average Kappa indexes with each of two manual results were 0.94 and 0.93, respectively. These results showed this method was both robust and accurate for cerebellum segmentation. The method may be applied to various research and clinical investigation in which cerebellum segmentation and quantitative MR measurement of cerebellum are needed.

Shan, Zu Y.; Ji, Qing; Glass, John; Gajjar, Amar; Reddick, Wilburn E.

2005-04-01

124

Patient specific tumor growth prediction using multimodal images.  

PubMed

Personalized tumor growth model is valuable in tumor staging and therapy planning. In this paper, we present a patient specific tumor growth model based on longitudinal multimodal imaging data including dual-phase CT and FDG-PET. The proposed Reaction-Advection-Diffusion model is capable of integrating cancerous cell proliferation, infiltration, metabolic rate and extracellular matrix biomechanical response. To bridge the model with multimodal imaging data, we introduce Intracellular Volume Fraction (ICVF) measured from dual-phase CT and Standardized Uptake Value (SUV) measured from FDG-PET into the model. The patient specific model parameters are estimated by fitting the model to the observation, which leads to an inverse problem formalized as a coupled Partial Differential Equations (PDE)-constrained optimization problem. The optimality system is derived and solved by the Finite Difference Method. The model was evaluated by comparing the predicted tumors with the observed tumors in terms of average surface distance (ASD), root mean square difference (RMSD) of the ICVF map, average ICVF difference (AICVFD) of tumor surface and tumor relative volume difference (RVD) on six patients with pathologically confirmed pancreatic neuroendocrine tumors. The ASD between the predicted tumor and the reference tumor was 2.4±0.5mm, the RMSD was 4.3±0.4%, the AICVFD was 2.6±0.6%, and the RVD was 7.7±1.3%. PMID:24607911

Liu, Yixun; Sadowski, Samira M; Weisbrod, Allison B; Kebebew, Electron; Summers, Ronald M; Yao, Jianhua

2014-04-01

125

Quality of life and patient satisfaction after microsurgical abdominal flap versus staged expander/implant breast reconstruction: a critical study of unilateral immediate breast reconstruction using patient-reported outcomes instrument BREAST-Q.  

PubMed

Staged expander-implant breast reconstruction (EIBR) and microsurgical abdominal flap breast reconstruction (MAFBR) are the most common modes of breast reconstruction (BR) in the United States. Whether the mode of breast reconstruction has an impact on patient quality of life (QoL) and satisfaction remains a question. A retrospective study was conducted identifying a population of 119 patients who underwent unilateral immediate BR. Only patients who were eligible for either EIBR or MAFBR based on preoperative characteristics were included in the study. The following parameters were retrieved: demographics, mode of reconstruction, cancer, recovery, QoL, and patient satisfaction. The latter two parameters were determined using the BREAST-Q BR module questionnaire. Two-way analysis of variance with mode of reconstruction and occurrence of complication as independent variables was used to determine the effect on patient satisfaction and QoL. The association between mode of reconstruction and patient response with each item of the QoL and satisfaction survey domains was analyzed. The overall response rate was 62.2 %. Non-respondents and respondents did not significantly differ in demographics, surgery type, cancer staging, adjuvant therapy, and complication rate. Age and BMI were significantly higher in MAFBR, while level of education was higher in EIBR. MAFBR had higher scores in psychosocial and sexual wellbeing, satisfaction with outcome, breast, information, and plastic surgeon when compared with patients who underwent EIBR. For patients eligible for both MAFBR and EIBR, MAFBR is associated with higher levels of satisfaction and QoL. Comprehensive pre-operative information of pros and cons of both modes of BR is crucial for patients to make a well-informed decision, thus, resulting in higher levels of satisfaction. PMID:24831775

Liu, Chunjun; Zhuang, Yan; Momeni, Arash; Luan, Jie; Chung, Michael T; Wright, Eric; Lee, Gordon K

2014-07-01

126

Fox Chase study finds breast cancer patients face increasing number of imaging visits before surgery:  

Cancer.gov

Breast cancer patients frequently undergo imaging like mammograms or ultrasounds between their first breast cancer-related doctor visit and surgery to remove the tumor. In recent years, however, imaging has increased in dramatic and significant ways, say researchers from Fox Chase Cancer Center. More patients have repeat visits for imaging than they did 20 years ago, and single imaging appointments increasingly include multiple types of imaging.

127

Impact of miscentering on patient dose and image noise in x-ray CT imaging: phantom and clinical studies.  

PubMed

The operation of the bowtie filter in x-ray CT is correct if the object being scanned is properly centered in the scanner's field-of-view. Otherwise, the dose delivered to the patient and image noise will deviate from optimal setting. We investigate the effect of miscentering on image noise and surface dose on three commercial CT scanners. Six cylindrical phantoms with different size and material were scanned on each scanner. The phantoms were positioned at 0, 2, 4 and 6 cm below the isocenter of the scanner's field-of-view. Regression models of surface dose and noise were produced as a function of miscentering magnitude and phantom's size. 480 patients were assessed using the calculated regression models to estimate the influence of patient miscentering on image noise and patient surface dose in seven imaging centers. For the 64-slice CT scanner, the maximum increase of surface dose using the CTDI-32 phantom was 13.5%, 33.3% and 51.1% for miscenterings of 2, 4 and 6 cm, respectively. The analysis of patients' scout scans showed miscentering of 2.2 cm in average below the isocenter. An average increase of 23% and 7% was observed for patient dose and image noise, respectively. The maximum variation in patient miscentering derived from the comparison of imaging centers using the same scanner was 1.6 cm. Patient miscentering may substantially increase surface dose and image noise. Therefore, technologists are strongly encouraged to pay greater attention to patient centering. PMID:21741870

Habibzadeh, M A; Ay, M R; Asl, A R Kamali; Ghadiri, H; Zaidi, H

2012-07-01

128

Cine MR imaging of uterine peristalsis in patients with endometriosis.  

PubMed

Endometriosis is one of the most important causes of infertility; however the precise mechanism by which it affects female fertility is unclear. The objective of this study was to study the functional aspects of the uterus by evaluating uterine contractility in patients with endometrial cysts of the ovary. The study population was recruited from two institutes and consisted of 26 women (periovulatory (10), luteal (13), and menstrual phase (3); age range: 19-51 years) with untreated endometriosis; the control group consisted of 12 healthy women (age range: 22-41 years). Cine MR imaging obtained by a 1.5T magnet was visually evaluated at 12x faster than real speed, focusing on the presence of uterine peristalsis, the direction and frequency of peristalsis, and the presence of sustained uterine contractions. Uterine peristalsis was identifiable in 3/10, 3/13, and 3/3 of the endometriosis patients in each menstrual cycle, respectively, and in 11/12, 3/12, and 5/12 of their control subjects. Peristaltic detection rate and frequency were significantly less for the endometriosis group than for the controls in the periovulatory phase only (p<0.05). Sustained contractions were recognized in 19/36 control subjects and in 13/26 endometriosis patients, but the difference was not significant. Uterine peristalsis appears to be suppressed during the periovulatory phase in patients with endometriosis, which may have an adverse effect on sperm transport. PMID:17119973

Kido, Aki; Togashi, Kaori; Nishino, Mizuki; Miyake, Kanae; Koyama, Takashi; Fujimoto, Ryota; Iwasaku, Kazuhiro; Fujii, Shingo; Hayakawa, Katsumi

2007-07-01

129

The use of magnetic resonance imaging in the obstetric patient.  

PubMed

Objective: To review the biological effects and safety of magnetic resonance imaging (MRI) in the obstetric patient and to review procedural issues, indications, and contraindications for obstetrical MRI. Outcomes: This guideline is intended to reassure patients and clinicians of the safety of MRI in pregnancy and to provide a framework for its use. Evidence: Published literature was retrieved through searches of PubMed or Medline in 2013 using controlled vocabulary and key words (e.g., MRI, safety, pregnancy). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies published in English and in French. There were no date restrictions. Searches were updated on a regular basis and incorporated in the guideline to July 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values: The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table). Benefits, harms, and costs: This article is intended to reassure obstetric care providers that if used in an appropriate manner without the use of contrast agents, MRI in the obstetrical patient is safe for mother and fetus in the second and third trimesters. Because obstetrical MRI is expensive and has limited availability in Canada, this clinical guideline is intended to encourage the judicious use of this resource. Summary Statements 1. Fetal magnetic resonance imaging is safe at 3.0 tesla or less during the second and third trimesters. (II-2) 2. It is safe to continue breastfeeding after receiving a gadolinium contrast agent. (III) Recommendations 1. Use of magnetic resonance imaging during the first trimester of pregnancy should be restricted to maternal indications for which the information is considered clinically imperative. Inadvertent exposure to magnetic resonance imaging during the first trimester has not been associated with any long-term sequelae and should not raise clinical concern. (III-C) 2. Gadolinium contrast may be used in pregnant women when the benefits outweigh the potential risks. (III-C). PMID:24798674

Patenaude, Yves; Pugash, Denise; Lim, Kenneth; Morin, Lucie; Lim, Kenneth; Bly, Stephen; Butt, Kimberly; Cargill, Yvonne; Davies, Gregory; Denis, Nanette; Hazlitt, Gail; Morin, Lucie; Naud, Kentia; Ouellet, Annie; Salem, Shia

2014-04-01

130

Magical NiTi expander.  

PubMed

A 24-year-old male patient was referred to our department for expansion of the constricted maxillary arch as a presurgical procedure for the correction of congenital facial disfigurement. On examination, the patient had a convex profile, increased interlabial gap, tongue thrust, limited mouth opening, posterior crossbite, asymmetric 'V'-shaped maxillary arch with severe constriction, crowding of anterior teeth in the maxillary arch and a massive open bite. Radiographic investigations included orthopantomograph and occlusal radiographs. The patient photographs and models were analysed. On careful evaluation, the treatment for maxillary arch expansion was planned with a nickel titanium (NiTi) slow maxillary expander along with fixed mechanotherapy for alignment of teeth. An unexpectedly successful outcome was appreciated from the treatment. An emphasis should be laid on selecting and treating the case of constricted arches with a surgical or non-surgical approach, as expansion can be achieved orthodontically by using NiTi expanders. PMID:23867876

Katti, Chandrika Girish; Katti, Girish; Kallur, Ravi; Ghali, Srinivas Rao

2013-01-01

131

Expandable space frames  

NASA Technical Reports Server (NTRS)

Expandable space frames having essentially infinite periodicity limited only by practical considerations, are described. Each expandable space frame comprises a plurality of hinge joint assemblies having arms that extend outwardly in predetermined symmetrically related directions from a central or vertex point. The outer ends of the arms form one part of a hinge point. The outer expandable space frame also comprises a plurality of struts. The outer ends of the struts from the other part of the hinged joint. The struts interconnect the plurality of hinge point in sychronism, the spaceframes can be expanded or collapsed. Three-dimensional as well as two-dimensional spaceframes of this general nature are described.

Schoen, A. H. (inventor)

1973-01-01

132

Multislice CT Scans in Patients on Extracorporeal Membrane Oxygenation: Emphasis on Hemodynamic Changes and Imaging Pitfalls  

PubMed Central

This pictorial review provides the principles of extracorporeal membrane oxygenation (ECMO) support and associated CT imaging features with emphasis on the hemodynamic changes and possible imaging pitfalls encountered. It is important that radiologists in ECMO centers apply well-designed imaging protocols and familiarize themselves with post-contrast CT imaging findings in patients on ECMO.

Liu, Kao-Lang; Wang, Yu-Feng; Chang, Yeun-Chung; Huang, Shu-Chien; Chen, Shyh-Jye; Tsang, Yuk-Ming

2014-01-01

133

Applying a patient-specific bio-mathematical model of glioma growth to develop virtual [18F]-FMISO-PET images  

PubMed Central

Glioblastoma multiforme (GBM) is a class of primary brain tumours characterized by their ability to rapidly proliferate and diffusely infiltrate surrounding brain tissue. The aggressive growth of GBM leads to the development of regions of low oxygenation (hypoxia), which can be clinically assessed through [18F]-fluoromisonidazole (FMISO) positron emission tomography (PET) imaging. Building upon the success of our previous mathematical modelling efforts, we have expanded our model to include the tumour microenvironment, specifically incorporating hypoxia, necrosis and angiogenesis. A pharmacokinetic model for the FMISO-PET tracer is applied at each spatial location throughout the brain and an analytical simulator for the image acquisition and reconstruction methods is applied to the resultant tracer activity map. The combination of our anatomical model with one for FMISO tracer dynamics and PET image reconstruction is able to produce a patient-specific virtual PET image that reproduces the image characteristics of the clinical PET scan as well as shows no statistical difference in the distribution of hypoxia within the tumour. This work establishes proof of principle for a link between anatomical (magnetic resonance image [MRI]) and molecular (PET) imaging on a patient-specific basis as well as address otherwise untenable questions in molecular imaging, such as determining the effect on tracer activity from cellular density. Although further investigation is necessary to establish the predictive value of this technique, this unique tool provides a better dynamic understanding of the biological connection between anatomical changes seen on MRI and biochemical activity seen on PET of GBM in vivo.

Gu, Stanley; Chakraborty, Gargi; Champley, Kyle; Alessio, Adam M.; Claridge, Jonathan; Rockne, Russell; Muzi, Mark; Krohn, Kenneth A.; Spence, Alexander M.; Alvord, Ellsworth C.; Anderson, Alexander R. A.; Kinahan, Paul E.; Swanson, Kristin R.

2012-01-01

134

Water expandable polystyrene (WEPS)  

Microsoft Academic Search

In Part 1 (Polymer 1999;40:3685) of this series, the concept for the preparation of expandable polystyrene (PS) applying water as a blowing agent was presented. This paper focuses on the expansion characteristics of water expandable polystyrene (WEPS) beads. The influence of temperature, amount of blowing agent, molar mass of the PS matrix and slight crosslinking of the matrix were investigated

J. J. Crevecoeur; J. F. Coolegem; L. Nelissen; P. J. Lemstra

1999-01-01

135

Water expandable polystyrene (WEPS)  

Microsoft Academic Search

Conventional expandable polystyrene (PS) is prepared via the suspension polymerisation of styrene containing pentane isomers as a blowing agent. The polystyrene beads are expanded by heating above the glass transition temperature, Tg. During the expansion process, pentane, which contributes to the formation of ozone in the lower atmosphere, is released into the environment. The objective of this study was to

J. J. Crevecoeur; L. Nelissen; P. J. Lemstra

1999-01-01

136

Early molecular imaging of interstitial changes in patients after myocardial infarction: Comparison with delayed contrast-enhanced magnetic resonance imaging  

PubMed Central

Introduction The clinical feasibility of noninvasive imaging of interstitial alterations after myocardial infarction (MI) was assessed using a technetium-99m-labeled RGD imaging peptide (RIP). In experimental studies, RIP has been shown to target integrins associated with collagen-producing myofibroblasts (MFB). Methods and Results Ten patients underwent myocardial perfusion imaging (MPI) within the first week after MI. At 3 and 8 weeks after MI, RIP was administered intravenously and SPECT images acquired for interstitial imaging. RIP imaging was compared to initial MPI and to the extent of scar formation defined by late gadolinium-enhanced (LGE) cardiac magnetic resonance (CMR) imaging 1 year after MI. RIP uptake was observed in 7 of the 10 patients at both 3 and 8 weeks. Although, RIP uptake corresponded to areas of perfusion defects, it usually extended beyond the infarct zone to a variable extent; 2 of 7 patients showed tracer uptake throughout myocardium. In all positive cases, RIP uptake was similar to the extent of scar observed at 1 year by LGE-CMR imaging. Conclusion This study demonstrates that RGD-based imaging early after MI may predict the eventual extent of scar formation, which often exceeds initial MPI deficit but colocalizes with LGE in CMR imaging performed subsequently.

Verjans, Johan; Wolters, Sander; Laufer, Ward; Schellings, Mark; Lax, Michelle; Lovhaug, Dagfinn; Boersma, Hendrikus; Kemerink, Gerrit; Schalla, Simon; Gordon, Paul; Teule, Jaap

2010-01-01

137

Investigation of Gamma Knife image registration errors resulting from misalignment between the patient and the imaging axis  

Microsoft Academic Search

The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comfort. Results equally apply to magnetic resonance imaging. Seven 0.5 mm diameter CT-visible spheres were rigidly mounted

George Cernica; Wang Zhou; Harish Malhotra; Steven de Boer; Matthew B. Podgorsak

2006-01-01

138

Cost analysis of periprocedural imaging in patients undergoing catheter ablation for atrial fibrillation.  

PubMed

Cardiovascular imaging is an important part of procedural planning and safety for catheter ablation of atrial fibrillation (AF). However, the costs of imaging surrounding catheter ablation of AF have not been described. Medicare fee-for-service data were used to evaluate Medicare expenditures before, during, and after catheter ablation for AF from July 2007 to December 2009. Among 11,525 patients who underwent catheter ablation for AF, the mean overall expenditure on the day of the procedure was $14,455 (SD $7,441). The mean imaging expenditure in the periprocedural period, which included the 30 days before the catheter ablation and the day of the ablation itself, was $884 (SD $455). Periprocedural imaging expenditures varied by the imaging strategy used, ranging from a mean of $557 (SD $269) for patients with electroanatomic mapping only to $1,234 (SD $461) for patients with electroanatomic mapping, transesophageal echocardiogram, and computed tomography or magnetic resonance imaging. Mean patient-level imaging expenditures varied by provider (mean $872, SD $249). Periprocedural imaging expenditures also varied by patient risk, with mean expenditures of $862 (SD $444) for patients with a CHADS2 score of ?2 compared with $907 (SD $466) for CHADS2 score <2 (p <0.001). In conclusion, periprocedural imaging accounts for approximately 6% of mean Medicare expenditures for catheter ablation of AF. The expenditures for periprocedural imaging vary both at the patient and at the provider level and they are inversely related to stroke risk by CHADS2 score. PMID:24952929

Pokorney, Sean D; Hammill, Bradley G; Qualls, Laura G; Steinberg, Benjamin A; Curtis, Lesley H; Piccini, Jonathan P

2014-07-15

139

Patient-controlled sharing of medical imaging data across unaffiliated healthcare organizations  

PubMed Central

Background Current image sharing is carried out by manual transportation of CDs by patients or organization-coordinated sharing networks. The former places a significant burden on patients and providers. The latter faces challenges to patient privacy. Objective To allow healthcare providers efficient access to medical imaging data acquired at other unaffiliated healthcare facilities while ensuring strong protection of patient privacy and minimizing burden on patients, providers, and the information technology infrastructure. Methods An image sharing framework is described that involves patients as an integral part of, and with full control of, the image sharing process. Central to this framework is the Patient Controlled Access-key REgistry (PCARE) which manages the access keys issued by image source facilities. When digitally signed by patients, the access keys are used by any requesting facility to retrieve the associated imaging data from the source facility. A centralized patient portal, called a PCARE patient control portal, allows patients to manage all the access keys in PCARE. Results A prototype of the PCARE framework has been developed by extending open-source technology. The results for feasibility, performance, and user assessments are encouraging and demonstrate the benefits of patient-controlled image sharing. Discussion The PCARE framework is effective in many important clinical cases of image sharing and can be used to integrate organization-coordinated sharing networks. The same framework can also be used to realize a longitudinal virtual electronic health record. Conclusion The PCARE framework allows prior imaging data to be shared among unaffiliated healthcare facilities while protecting patient privacy with minimal burden on patients, providers, and infrastructure. A prototype has been implemented to demonstrate the feasibility and benefits of this approach.

Ahn, David K; Unde, Bhagyashree; Gage, H Donald; Carr, J Jeffrey

2013-01-01

140

Fluoroscopically guided insertion of self-expandable metal esophageal stents for palliative treatment of patients with malignant stenosis of esophagus and cardia: comparison of uncovered and covered stent types.  

PubMed

The aim of this retrospective study was to present and compare the results of using two different types of esophageal self-expanding stents (uncovered and covered) for palliative treatment of patients with inoperable malignant stenosis of the esophagus and cardia. Over a period of 8 years, 152 patients underwent fluoroscopically guided insertion of metal esophageal stents. We inserted uncovered esophageal nitinol Strecker stents in 54 patients (group I) and covered esophageal Ultraflex stents in the remaining 98 patients (group II). The stent insertion procedure was successively performed in all patients. Closure of esophageal fistula by covered stents was achieved in 8/8 patients. Mean dysphagia score was significantly decreased in both patient groups at 4 weeks follow-up: from 2.73 before stent insertion to 0.15 in group I, and from 2.67 to 0.05 in group II (on 0-4 scale). Eighty-eight per cent of patients with covered stents and 54% with uncovered type were free of symptoms during follow-up. Complications occurring during follow-up and their comparative frequency in the two groups of patients were as follows (group I: group II%): stent migration (0:10%); tumor or granulation tissue ingrowth (100:53%); overgrowth at the ends of stents (17:30%); restenosis causing recurrent dysphagia (37:8%); and appearance of esophageal fistulas (8:6%). In conclusion, fluoroscopically guided insertion of self-expandable esophageal stents is a safe and comfortable method of palliation for patients suffering with malignant dysphagia. In selection of a stent, covered types should be given priority for prevention of restenosis. PMID:16128779

Saranovic, Dj; Djuric-Stefanovic, A; Ivanovic, A; Masulovic, D; Pesko, P

2005-01-01

141

Expanding the Universe  

NASA Astrophysics Data System (ADS)

Proceedings of the International Conference EXPANDING THE UNIVERSE, On the occasion of the 200th anniversary of the Tartu Observatory, Tartu, Estonia 2011 April 27-29. C. Sterken, L. Leedjarv, E. Tempel (Eds.)

Sterken, Christiaan; Leedjärv, Laurits; Tempel, Elmo

2011-12-01

142

Evidence for the Expanding Universe  

NSDL National Science Digital Library

In this activity, students examine the first line of evidence, galactic motion, for the notion of an expanding universe. By examining the spectrum of light from a galaxy, students can determine whether a galaxy is moving toward or away from us, and how fast. Students will look at optical images of four galaxies, compare the emission spectra from these same four galaxies, and measure the wavelength of the red hydrogen line for each galaxy. This activity is part of the "Cosmic Questions" educator's guide developed to support the Cosmic Questions exhibit. This activity can be used in conjunction with, or independently of, the exhibit.

143

Patient-Specific Models for Lung Nodule Detection and Survellience in CT Images  

Microsoft Academic Search

The purpose of this work is to develop patient-specific models for automatically detecting lung nodules in computed tomography (CT) images. It is motivated by significant developments in CT scanner technology and the burden that lung cancer screening and surveillance imposes on radiologists. We propose a new method that uses a patient's baseline image data to assist in the segmentation of

Matthew S. Brown; Michael F. Mcnitt-gray; Jonathan G. Goldin; Robert D. Suh; James W. Sayre; Denise R. Aberle

2001-01-01

144

Magnetic resonance imaging of the shoulder in patients with rheumatoid arthritis  

Microsoft Academic Search

To evaluate the ability of magnetic resonance imaging (MRI) to detect shoulder abnormalities 18 patients (36 shoulders) with rheumatoid arthritis (RA) and shoulder complaints were studied. Osseous abnormalities of the glenoid and humeral head were readily detected with MRI. The imaging planes used were not suitable for the evaluation of acromioclavicular joint involvement. Magnetic resonance imaging depicted soft tissue abnormalities

G J Kieft; B A Dijkmans; J L Bloem; H M Kroon

1990-01-01

145

A patient positioning system for the ESRF medical imaging facility  

Microsoft Academic Search

The medical imaging facility of the ESRF is devoted to human coronary angiography, computed tomography, diffraction enhanced imaging (DEI), bronchography, and also radiation therapy programs. Most of the imaging is performed in a satellite building located at 150m from the wiggler source (H. Elleaume et al., Nucl. Instr. and Meth. A 428 (1999) 513). A multi-purpose device known as the

Y. Dabin; A. Draperi; H. Elleaume; A. M. Charvet; T. Brochard; M. Perez; C. Nemoz; G. Blattmann; M. Renier; F. Fournier; J-L Dupuy; B. Lemoine; P. Bouhaniche; W. Thomlinson; P. Suortti

2001-01-01

146

An Adaptive Approach to Decomposing Patient-Motion Tracking Data Acquired During Cardiac SPECT Imaging  

Microsoft Academic Search

Patient motion during cardiac SPECT imaging can cause diagnostic imaging artifacts. We have implemented a Neural Network (NN) approach to decompose monitored patient motion data, gathered during cardiac SPECT imaging, using the Polaris stereo-IR real-time motion-tracking system. Herein, we show the successful decomposition of Polaris motion data into rigid body motion (RBM) and respiratory motion (RM). The motivation for separating

Richard D. Beach; Hans Depold; Guido Boening; Philippe P. Bruyant; Bing Feng; Howard C. Gifford; Michael A. Gennert; Suman Nadella; Michael A. King

2007-01-01

147

Imaging axillary lymph nodes in patients with newly diagnosed breast cancer.  

PubMed

The presence of axillary lymph node metastasis in patients newly diagnosed with breast cancer carries significant prognostic and management implications. As a result, there is increasing interest to stage accurately the axilla with preoperative imaging to facilitate treatment planning. Currently, the most widespread imaging techniques for the evaluation of the axilla include ultrasound and magnetic resonance imaging. In many settings, the ability to detect axillary lymph nodes containing metastases with imaging and image-guided biopsy can allow surgeons to bypass sentinel lymph node dissection and proceed with full axillary lymph node dissection. However, no imaging modality currently has sufficient negative-predictive value to obviate surgical staging of the axilla if no abnormal lymph nodes are detected. Promising advanced imaging technologies, such as diffusion-weighted imaging and magnetic resonance lymphangiography, hold the potential to improve the accuracy of axillary staging and thereby transform management of the axilla in patients newly diagnosed with breast cancer. PMID:22818835

Rahbar, Habib; Partridge, Savannah C; Javid, Sara H; Lehman, Constance D

2012-01-01

148

Implications of Surface-Rendered Facial CT Images in Patient Privacy.  

PubMed

OBJECTIVE. Three-dimensional and multiplanar reconstruction of CT images has become routine in diagnostic imaging. The technology also facilitates surface reconstruction, in which facial features and, as a result, patient identity may be recognized, leading to risk of violations of patient privacy rights. The purpose of this study was to assess whether volunteer viewers can recognize faces on 3D reconstructed images as specific patients. SUBJECTS AND METHODS. A total of 328 participants were included: 29 patients underwent clinically indicated CT of the maxillofacial sinuses or cerebral vasculature and were also photographed (group A); 150 patients volunteered to have their faces photographed (group B); and 149 observers reviewed the images. Surface-reconstructed 3D images of group A were generated from CT data, and digital photographs of both groups A and B were acquired for a total of 179 facial photographs. Image reviewers were recruited with a web-based questionnaire that required observers to match surface-reconstructed images generated from CT data with randomized digital photographs from among the 179 photographs. Data analyses were performed to determine the ability of observers to successfully match surface-reconstructed images with facial photographs. RESULTS. The overall accuracy among the image observers was approximately 61%. No significant differences were found with regard to sex, age, or ethnicity and accuracy of image observers. CONCLUSION. Image reviewers were relatively poor at even side-by-side matching of patient photographs with 3D surface-reconstructed images. This finding suggests that successful identification of patients using surface-rendered faces may be a relatively difficult task for observers. PMID:24848824

Chen, Joseph Jen-Sho; Juluru, Krishna; Morgan, Tara; Moffitt, Ryan; Siddiqui, Khan M; Siegel, Eliot L

2014-06-01

149

The VA's use of DICOM to integrate image data seamlessly into the online patient record.  

PubMed

The US Department of Veterans Affairs (VA) is using the Digital Imaging and Communications in Medicine (DICOM) standard to integrate image data objects from multiple systems for use across the healthcare enterprise. DICOM uses a structured representation of image data and a communication mechanism that allows the VA to easily acquire radiology images and store them directly into the online patient record. Images can then 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. Various image and study specific items from the DICOM data object are essential for the correct display of images. The VA's DICOM capabilities are now used to interface seven different commercial Picture Archiving and Communication Systems (PACS) and over twenty different radiology image acquisition modalities. PMID:10566327

Kuzmak, P M; Dayhoff, R E

1999-01-01

150

Magnetic resonance imaging in patients with progressive myelopathy following spinal surgery.  

PubMed Central

Thirty one patients with insidious progressive myelopathy 2 to 8 years following surgery of the cervical spine were subjected to magnetic resonance imaging (MRI). In 15 patients operated on for vascular malformations or intramedullary tumours, syringomyelia and cystic lesions of the spinal cord were shown. Seven of these patients also showed a combination of a recurrent tumour and spinal atrophy. Out of 16 patients who had surgery for herniated disc or spinal stenosis of the cervical spine, four had syringomyelia and 12 had spinal cord atrophy. There was no syringomyelia in the 12 patients submitted to MRI prior to surgery. Images

Avrahami, E; Tadmor, R; Cohn, D F

1989-01-01

151

Development of a cardiovascular calcification index using simple imaging tools in haemodialysis patients  

Microsoft Academic Search

Background. Coronary artery calcification (CAC) is highly prevalent in haemodialysis patients and is associated with cardiovascular outcomes. Though cardiac computed tomography (CCT) is accurate, it is not widely available. Methods. We developed a cardiovascular calcification index (CCI) to predict the presence of CAC for haemodialysis patients using simple in-office techniques. Prevalent haemodialysis patients (n ¼ 140) underwent CCT imaging for

Paul Muntner; Emiliana Ferramosca; Antonio Bellasi; Geoffrey A. Block; Paolo Raggi

2007-01-01

152

Value of single photon emission computerized imaging in the treatment of patients undergoing carotid endarterectomy  

Microsoft Academic Search

Purpose: The purpose of this study was to evaluate the clinical relevance of regional cerebral blood flow by single photon emission computerized imaging (SPECT) in patients undergoing carotid endarterectomy (CEA).Method: Eighty-four patients were included in this study; 74 were undergoing CEA. All 74 operative cases had SPECT scans before and after surgery. The first 30 patients undergoing CEA also had

Roy L. Tawes; Robert Lull

1996-01-01

153

Changes in the surgical management of patients with breast carcinoma based on preoperative magnetic resonance imaging  

Microsoft Academic Search

BACKGROUND. Breast magnetic resonance imaging (MRI) is a developing technique for the evaluation of patients with primary breast carcinoma. The authors assessed the impact of preoperative breast MRI on surgical management. METHODS. The current study was a retrospective review of 267 patients with primary breast tumors who had MRI studies prior to undergoing definitive surgery. RESULTS. Two hundred sixty-seven patients

Isabelle Bedrosian; Rosemarie Mick; Susan G. Orel; Mitchell Schnall; Carol Reynolds; Francis R. Spitz; Linda S. Callans; Gordon P. Buzby; Ernest F. Rosato; Douglas L. Fraker; Brian J. Czerniecki

2003-01-01

154

Holography and the virtual patient: the holographic medical image  

Microsoft Academic Search

Practical holographic systems utilizing the pulsed laser are finding potential applications in medicine. Exploiting both the hologram's true 3D image and holographic interferometry these techniques enhance the physician's vision beyond the 2D radiological imaging of even the best CT and MRI. The authors describe the use of pulsed laser holography as applied to the morphological specialties: anatomy, pathology, and surgery.

Kathryn Ko; Ronald R. Erickson; John M. Webster

1996-01-01

155

Tabbed Tissue Expanders Improve Breast Symmetry Scores in Breast Reconstruction  

PubMed Central

Background Achieving symmetry is a key goal in breast reconstruction. Anatomically shaped tabbed expanders are a new tool in the armamentarium of the breast reconstruction surgeon. Suture tabs allow for full control over the expander position and thus inframammary fold position, and, in theory, tabbed expanders mitigate many factors responsible for poor symmetry. The impact of a tabbed expander on breast symmetry, however, has not been formally reported. This study aims to evaluate breast symmetry following expander-implant reconstruction using tabbed and non-tabbed tissue expanders. Methods A chart review was performed of 188 consecutive expander-implant reconstructions that met the inclusion criteria of adequate follow-up data and postoperative photographs. Demographic, oncologic, postoperative complication, and photographic data was obtained for each patient. The photographic data was scored using a 4-point scale assessing breast symmetry by three blinded, independent reviewers. Results Of the 188 patients, 74 underwent reconstruction with tabbed expanders and 114 with non-tabbed expanders. The tabbed cohort had significantly higher symmetry scores than the non-tabbed cohort (2.82/4±0.86 vs. 2.55/4±0.92, P=0.034). Conclusions The use of tabbed tissue expanders improves breast symmetry in tissue expander-implant-based breast reconstruction. Fixation of the expander to the chest wall allows for more precise control over its location and counteracts the day-to-day translational forces that may influence the shape and location of the expander pocket, mitigating many factors responsible for breast asymmetry.

Khavanin, Nima; Gust, Madeleine J; Grant, David W; Nguyen, Khang T

2014-01-01

156

Creation of a Reference Image with Monte Carlo Simulations for Online EPID Verification of Daily Patient Setup.  

National Technical Information Service (NTIS)

Patient positioning accuracy remains an issue for external beam radiotherapy. Currently, kilovoltage verification images are used as reference by clinicians to compare the actual patient treatment position with the planned position. These images are quali...

M. A. Descalle C. F. Chuang J. Pouliot

2002-01-01

157

Expanded Roles for HRD.  

ERIC Educational Resources Information Center

This document contains three papers from a symposium on expanded roles for human resource development (HRD). "The Roles of Consultants in Gainsharing Firms: Empirical Results" (Eunsang Cho, Gary N. McLean) reports findings that consultants are moderately involved at the separation, preparation, evaluation, and design stages and have low…

1998

158

Expanding community psychology's domain  

Microsoft Academic Search

Community psychology's twin goals of prevention and empowerment are ill-served when researchers and practitioners restrict their activities to traditional mental health settings. This paper echoes the call of the Swampscott conference for expanding community psychology's domain of inquiry and action. It reviews examples from the research literature of efforts at prevention and empowerment in five classes of behavior settings identified

Marybeth Shinn

1987-01-01

159

Expanding hollow metal rings  

Microsoft Academic Search

A sealing device that may expand more planar dimensions due to internal thermal expansion of a filler material. The sealing material is of a composition such that when desired environment temperatures and internal actuating pressures are reached, the sealing materials undergoes a permanent deformation. For metallic compounds, this permanent deformation occurs when the material enters the plastic deformation phase. Polymers,

Harold B. Peacock; Kenneth J. Imrich

2009-01-01

160

The Expanding Universe  

NSDL National Science Digital Library

This activity demonstrates with balloons the expansion of the universe. Distances between points on the balloon are meausred as the balloon expands, showing how all are getting farther apart. After the activity the students are asked questions about the universe's expansion.

Slater, Tim P.

2004-07-16

161

EXPANDED BED BIOLOGICAL TREATMENT  

EPA Science Inventory

A three-year pilot-scale research investigation at the EPA Lebanon Pilot Plant was conducted to evaluate the feasibility of a unique biological secondary treatment process, designated the Expanded Bed Biological Treatment Process (EBBT). The EBBT process is a three-phase (oxygen/...

162

Magnetic resonance imaging findings in patients with delusional disorder due to diffuse cerebrovascular disease: a report of seven cases.  

PubMed

Delusions associated with cerebrovascular diseases have been sporadically reported. Although both psychiatrists and neurologists attempted to link delusions with anatomical locations of the brain lesion, comorbid psychiatric and neurological disorders make the interpretation of delusions difficult. The purpose of the present paper is to report the clinical features and magnetic resonance imaging (MRI) characteristics in patients with delusional disorder due to diffuse cerebrovascular diseases, and to redefine the concept of 'vascular delusion'. The clinical features and MRI findings were reviewed retrospectively in a series of seven patients with 'delusional disorder due to cerebrovascular disease' as defined in Diagnostic and Statistical Manual of Mental Disorders (DSMIV). The average age of onset is 64. No patient had a prior personal or family history of major psychiatric illness. The illness is presented as acute, subacute or stepwise course. Hypertension was present in all patients. Two had diabetes mellitus, and one had atrial fibrillation. Three had clinical evidence of previous cerebrovascular attacks, only one showed minor neurological deficits. Three had diffuse cortical slow wave in electroencephalogram. No patient had significant cognitive impairment but had multiple cortical and subcortical cerebrovascular lesions in MRI, with white-matter lesions (WML) in bilateral frontal areas. Delusional disorder due to diffuse cerebrovascular change is characterized by late-onset, stepwise course, and comorbid medical and neurological diseases. The results of vascular changes in the present study did not establish a cause-effect relationship and should be considered as multifactorial in pathogenesis. The findings suggested the hypothesis of neural circuit theory. Further studies in larger numbers of patients and newer neuroimaging techniques are needed to expand the knowledge learned from these findings. PMID:11285090

Su, K P; Hsu, C Y; Hsieh, S C; Shen, W W

2001-04-01

163

Development of A Novel Image Guidance Alternative for Patient Localization using Topographic Images for TomoTherapy  

NASA Astrophysics Data System (ADS)

To develop a faster and lower dose topogram based image registration for TomoTherapy as an alternative image guidance tool to volumetric megavoltage computed tomography (MVCT). Topogram procedures were performed for an anthropomorphic thorax phantom on a TomoTherapy HD unit (Accuray Inc., Sunnyvale, CA) using couch speeds from 1-4 cm/s and gantry angles of 0 and 90 degrees, other scanning parameters are: 1 mm imaging jaw, compression factor of 1, 30 seconds scanning duration with all multileaf collimators (MLCs) open. The raw exit detector data was exported after each scan. The topogram was reconstructed from a fan beam source for TomoTherapy beam and detector geometry at a SSD of 85 cm. A reference image, so called Digitally Reconstructed Topogram (DRT) was created by integrating the trajectories through the kVCT simulation with the topogram geometry. Image registration was performed by visually aligning the bony structure in topogram to the DRT. Image resolution was determined by the radius of curvature for the detector array, source to axis distance, source to detector distance, detector spacing, and number of detectors. The localization errors were 1.5, 2.5 mm in medio-lateral and anterior-posterior direction, larger errors in cranial-caudal direction was observed for faster couch speeds (i.e., >=3cm/s). The topographic imaging time was 30 sec (versus 3-5 minutes for MVCT thorax scan) with imaging dose less than 1% of MVCT scan. Topograms with appropriate couch speed provide reliable patient localization images while significantly reducing pre-treatment imaging time. Topogram can be used as an alternative and/or additional patient alignment tool to MVCT on TomoTherapy.

Qi, X. Sharon; White, Benjamin; Low, Daniel A.

2014-03-01

164

Who am I? Reflections on self-image among patients with cancer in clinical trials.  

PubMed

Patients with cancer who participate in research face difficult challenges. Their lives change in many ways, and they often question their self-image. Self-image includes how patients see themselves and who they want to become. The current commentary addresses the issue of self-image in patients with cancer who participate in clinical trials and how their sense of who they were changes as they shift from patients with cancer to research participants. Patients with cancer who participate in research may suffer from multiple identity transitions, ranging from physical alterations in appearance and bodily capabilities to psychological burdens of job loss and the inability to contribute financially to their families. The author aims to provide insight as to how researchers can help patients find meaning in their lives during the process of participation in clinical trials as they undergo identity transitions. PMID:24305493

Ulrich, Connie M

2013-12-01

165

Malignant peritoneal mesothelioma in two pediatric patients: MR imaging findings  

Microsoft Academic Search

Malignant mesothelioma is a rare tumor in childhood. We present two cases of malignant peritoneal mesothelioma in which contrast-enhanced,\\u000a fat-saturated magnetic resonance (MR) imaging was used advantageously to detect peritoneal tumor involvement.

Mithat Haliloglu; Fredric A. Hoffer; Barry D. Fletcher

2000-01-01

166

Compendium of national guidelines for imaging of the pediatric patient  

Microsoft Academic Search

Background  Diagnostic imaging plays an integral role in diagnosing and managing many pediatric disorders, but there is growing concern\\u000a in both the medical community and the general public about the long-term health effects of ionizing radiation in children,\\u000a as well as utilization of imaging evaluation. These concerns, coupled with increasing pressure to reduce national health care\\u000a spending, underscore the need for

Cameron H. Williams; Donald P. Frush

167

The Psychiatric View of Patients of Aesthetic Surgery: Self-Esteem, Body Image, and Eating Attitude  

Microsoft Academic Search

The patient who presents for aesthetic surgery possesses various demands depending on the characteristic properties of the individual. Evaluation of self-esteem, body image and eating habits in patients of aesthetic surgery could help in understanding patients and their demands. We performed Rosenberg Scale Test for evaluation of self-esteem on 98 patients who presented for any kind of aesthetic surgery. Seventy-five

Murat S Sahin Alagoz; Ay?e Devrim Ba?terzi; Ahmet Ça?r? Uysal; Verda Tüzer; Ramazan Erkin Ünlü; Ömer ?ensöz; Erol Göka

2003-01-01

168

Magnetic resonance imaging in patients with unstable angina: comparison with acute myocardial infarction and normals  

SciTech Connect

The role of magnetic resonance imaging in characterizing normal, ischemic and infarcted segments of myocardium was examined in 8 patients with unstable angina, 11 patients with acute myocardial infarction, and 7 patients with stable angina. Eleven normal volunteers were imaged for comparison. Myocardial segments in short axis magnetic resonance images were classified as normal or abnormal on the basis of perfusion changes observed in thallium-201 images in 22 patients and according to the electrocariographic localization of infarction in 4 patients. T2 relaxation time was measured in 57 myocardial segments with abnormal perfusion (24 with reversible and 33 with irreversible perfusion changes) and in 25 normally perfused segments. T2 measurements in normally perfused segments of patients with acute myocardial infarction, unstable angina and stable angina were within normal range derived from T2 measurements in 48 myocardial segments of 11 normal volunteers (42 +/- 10 ms). T2 in abnormal myocardial segments of patients with stable angina also was not significantly different from normal. T2 of abnormal segments in patients with unstable angina (64 +/- 14 in reversibly ischemic and 67 +/- 21 in the irreversibly ischemic segments) was prolonged when compared to normal (p less than 0.0001) and was not significantly different from T2 in abnormal segments of patients with acute myocardial infarction (62 +/- 18 for reversibly and 66 +/- 11 for irreversibly ischemic segments). The data indicate that T2 prolongation is not specific for acute myocardial infarction and may be observed in abnormally perfused segments of patients with unstable angina.

Ahmad, M.; Johnson, R.F. Jr.; Fawcett, H.D.; Schreiber, M.H.

1988-09-01

169

Diagnosis Performance of Different MR Imaging Signs of Cirrhosis: the Caudate to Right Lobe Ratio, the Posterior Right Hepatic Notch, and the Expanded Gallbladder Fossa  

PubMed Central

Background & Aims The purpose of the study is to evaluate the accuracy of the C/RL, RPN, and EGF in diagnosing cirrhosis. Methods The study population included 95 cirrhotic patients in the cirrhosis group (56 men, 39 women, age range 14-76;mean age 52.3) and 57 subjects in the control group (26 men, 31 women, age range 18-83;mean age 51). All MR examinations were performed by using the same protocol. Two radiologists independently assessed data sets in two different reading sessions. The sensitivity, specificity, and accuracy and the relative risk of the signs in diagnosing cirrhosis were calculated. The diagnosis accuracy of the C/RL sign was calculated using the ROC curve. The statistical significance of any difference of each sign between different classes of cirrhosis was also calculated. Results The interobserver agreement between the readers was excellent (?? 0.81;95% CI:0.92, 1.0). There was a significant statistical difference of the diagnostic value of C/RL, RPN, and EGF between cirrhotic patients and control group (p<0.001). The sensitivity, specificity, and accuracy of C/RL were 72%, 87%, and 78%; 67%, 87%, and 75% for RPN; and 49%, 91%, and 65% for EGF. C/RL (OR=18.95) and RPN (OR=14.74) showed a higher risk for cirrhosis compared to EGF (OR=14.74). There was a statistical significance difference between C/RL and EGF (p=0.002) and between RPN and EGF for Child A class of cirrhosis (p-0.037). Conclusion The C/RL and RPN have similar performance regarding the diagnosis of cirrhosis having a higher diagnostic performance compared to EGF in cirrhosis.

Bolog, N.; Oancea, I.; Andreisek, G.; Mangrau, Angelica; Caruntu, F.

2009-01-01

170

Performing functional magnetic resonance imaging in patients with Parkinson's disease treated with deep brain stimulation.  

PubMed

Deep brain stimulation (DBS) is a relatively novel treatment in advanced Parkinson's disease (PD). Functional magnetic resonance imaging (fMRI) is a useful technique for examining the effects of DBS both within the basal ganglia and its cortical connectivity. There are technical difficulties in imaging patients with PD, and the DBS itself can generate image artifacts. We describe aspects related to optimizing the fMRI acquisition parameters in patients with DBS and the results of sensorimotor activation tasks performed by four PD patients during hand, foot, and tongue movements, both before and after DBS implant. Provided that all safety conditions are followed, it is possible to perform fMRI in patients with PD and DBS. The standard DBS surgical procedure has to be slightly modified in order to reduce image artifacts. The event-related design provided increased power to detect sensorimotor cortex and basal ganglia activation. PMID:16671094

Arantes, Paula R; Cardoso, Ellison F; Barreiros, Maria A; Teixeira, Manoel J; Gonçalves, Márcia R; Barbosa, Egberto R; Sukwinder, Sukhi Shergill; Leite, Claudia C; Amaro, Edson

2006-08-01

171

Associations Among Speech, Eating, and Body Image Concerns for Surgical Patients with Head and Neck Cancer  

PubMed Central

Background Body image can be affected by bodily experiences extending beyond physical appearance. This study evaluated associations among speech, eating, and body image concerns for surgically treated patients with oral cavity, midface, and cutaneous cancers of the head and neck. Methods Using a cross-sectional design, 280 participants completed the Body Image Scale, a survey evaluating disease-specific body image issues, and the Functional Assessment of Cancer Therapy Scale – General. Results Participants with speech and eating concerns reported the highest levels of body image/appearance dissatisfaction compared to those without such concerns. This group also reported greater cognitive and behavioral difficulties associated with body image concerns and significantly higher levels of interest in psychosocial interventions to address appearance-related difficulties compared to all other participants. Conclusions Findings point to the need for more comprehensive psychosocial care for head and neck patients with speech and eating difficulties, which extends beyond functional rehabilitation.

Fingeret, Michelle Cororve; Hutcheson, Katherine A.; Jensen, Katrina; Yuan, Ying; Urbauer, Diana; Lewin, Jan S.

2014-01-01

172

Patient positioning with X-ray detector self-calibration for image guided therapy.  

PubMed

Automatic alignment estimation from projection images has a range of applications, but misaligned cameras induce inaccuracies. Calibration methods for optical cameras requiring calibration bodies or detectable features have been a matter of research for years. Not so for image guided therapy, although exact patient pose recovery is crucial. To image patient anatomy, X-ray instead of optical equipment is used. Feature detection is often infeasible. Furthermore, a method not requiring a calibration body, usable during treatment, would be desirable to improve accuracy of the patient alignment. We present a novel approach not relying on image features but combining intensity based calibration with 3D pose recovery. A stereoscopic X-ray camera model is proposed, and effects of erroneous parameters on the patient alignment are evaluated. The relevant camera parameters are automatically computed by comparison of X-ray to CT images and are incorporated in the patient alignment computation. The methods were tested with ground truth data of an anatomic phantom with artificially produced misalignments and available real-patient images from a particle therapy machine. We show that our approach can compensate patient alignment errors through mis-calibration of a camera from more than 5 mm to below 0.2 mm. Usage of images with artificial noise shows that the method is robust against image degradation of 2-5%. X-ray camera self-calibration improves accuracy when cameras are misaligned. We could show that rigid body alignment was computed more accurately and that self-calibration is possible, even if detection of corresponding image features is not. PMID:21809141

Selby, Boris Peter; Sakas, Georgios; Groch, Wolfgang-Dieter; Stilla, Uwe

2011-09-01

173

Self-image and perception of mother and father in psychotic and borderline patients.  

PubMed

Psychotic and borderline patients rated their self-image and their perception of their mother and father using the Structural Analysis of Social Behavior model (SASB). The borderline patients had more negative images of themselves and their parents, especially their fathers, than did the psychotic patients and the normal subjects, while the psychotic patients' ratings did not differ much from those of the normal subjects. The self-image was related to the images of both parents for borderline patients and normal subjects, while for the psychotic patients only the image of the mother was important for the self-image. In addition, the psychotic patients did not differentiate between the poles of control and autonomy in the introjected self-image. It was concluded that borderline patients are characterized by negative attachment, while psychotic patients are characterized by poor separation from the mother and poor differentiation between autonomy and control. The paper also discusses how this may influence the patients' relations to others. Psychotische und Borderline Patienten beurteilten ihr Selbstbild und ihre Wahrnehmung von Mutter und Vater mit Hilfe der strukturalen Analyse sozialen Verhaltens (SASB). Die Borderline Patienten hattten negativere Selbstbilder und Elternbilder (speziell Vaterbilder) als die psychotischen Patienten und gesunde Personen. Die Beurteilungen der psychotischen Patienten unterschieden sich dagegen nicht besonders von jenen Gesunder. Das Selbstbild stand in Beziehung zu beiden Elternbildern bei den Borderline Patienten und den Gesunden, während bei den psychotischen Patienten nur das Mutterbild für das Selbstbild bedeutsam war. Außerdem konnte bei den psychotischen Patienten nicht zwischen den Polen der Kontrolle und Autonomie bzgl. der introjizierten Selbstbilder differenziert werden. Aus den Ergebnissen wird gefolgert, dass Borderline Patienten durch eine negative Bindung charackterisiert sind, psychotische Patienten dagegen durch eine mangelnde Separation von ihren Müttern und eine geringe Differenzierung zwischen Autonomie und Kontrolle. Es wird außerdem diskutiert, wie die Ergebnisse auf die realen Beziehungen der Patienten zu anderen Menschen Einflus nehmen könnten. Des patients psychotiques et Borderline ont évalué leur image d'eux-mêmes et leur perception de leur mère et père à l'aide du modèle de l'Analyse Structural du Comportement Social (SASB. Les patients Borderline avaient des imagess plus négatives d'eux-mêmes et de leurs parents, surtout de leur père, que les patients psychotiques et les sujets normaux, alors que les patients psychotiques se jugeaient à peine différemment des sujets normaux. L'image de soi était en relation avec les images des deux parents pour les patients Borderline et pour les sujets normaux, alors que pour les patients psychotiques, seulement l'image de la mère jouait un rôle pour leur image. En plus, les patients psychotiques ne différenciaient pas entre les pôles de contrôle et d'autonomie dans l'image de soi introjectée. Nous en avons conclu que les patients Borderline se caractérisent par un attachement négatif, et les patients psychotiques par une faible séparation de la mère ainsi qu'une différenciation modeste entre autonomie et contrôle. L'influence de ceci sur les relations des patients avec les autrs est discutée dans cet article. Pacientes limítrofes y psicóticos evaluaron su autoimagen y la percepción que tenían de sus padres usando el modelo de Análisis estructural del comportamiento social (SASB). Los pacientes limítrofes registraron imágenes más negativas de sí mismos y de sus progenitores, especialmente de su padre, que los pacientes psicóticos y los normales, mientras que las evaluaciones de los pacientes psicóticos no difirieron mucho de las de los sujetos normales. La autoimagen tuvo relación con la imagen de ambos progenitores tanto en el caso de los pacientes limítrofes como de los sujetos normales, mientras que para los pacientes psicóticos no diferenciaron entre control y autonomía en la a

Armelius, K; Granberg

2000-02-01

174

Grazing incidence beam expander  

SciTech Connect

A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

1985-01-01

175

Water expandable polystyrene (WEPS)  

Microsoft Academic Search

In Part 1 of this series (Polymer 1999;40:3685), the concept for the preparation of expandable polystyrene (PS) applying water as a blowing agent was presented. In order to achieve this goal, water was emulsified by means of a commercially available surfactant (sodium bis(2-ethylhexyl)sulfosuccinate) in a prepolymerised styrene\\/PS mixture. This mixture was subsequently suspended in water and polymerisation was continued to

J. J. Crevecoeur; L. Nelissen; P. J. Lemstra

1999-01-01

176

The Expanding Place Value  

NSDL National Science Digital Library

This collection of three lesson plans is designed to provide students with practice understanding place value (0 to 999), using standard and word form to represent numbers, and using expanded form to represent place value. Each lesson plan provides activities that will help build student understanding of the concepts and practice to help reinforce the skill. Thirteen resource sheets are included and can be used with these lessons or as independent activities.

Thomson, Erin; Pugh, Dana

2005-01-01

177

Diagnostic MR imaging features of craniocerebral Aspergillosis of sino-nasal origin in immunocompetent patients  

Microsoft Academic Search

Summary  Background. Craniocerebral invasive Aspergillosis of sino-nasal origin has been reported with a very high mortality due to a peculiarly fulminant clinical course. Early diagnosis\\u000a based on clinical radiological imaging may have an impact on final clinical outcome. This retrospective study focuses on characteristic\\u000a MR imaging features of Aspergillosis (of sinonasal origin) in immunocompetent patients.\\u000a \\u000a Methods. Medical records of patients were

A. A. Siddiqui; S. H. Bashir; A. Ali Shah; Z. Sajjad; N. Ahmed; R. Jooma; S. Ather Enam

2006-01-01

178

Disturbed myelination in patients with treated hyperphenylalaninaemia: evaluation with magnetic resonance imaging  

Microsoft Academic Search

Cranial magnetic resonance imaging (MRI) was performed in nine treated adolescents with hyperphenylalaninaemia (HPA) in order to analyse possible changes in myelination. Three patients suffered from type I HPA, four from type II and two from type III (persistent HPA). Images were obtained with a 1.5T unit using spin-echo-sequences. In all patients with type I or type II HPA, abnormal

U. Bick; G. Fahrendorf; A. C. Ludolph; P. Vassallo; J. Weglage; K. Ullrich

1991-01-01

179

Body Image and Quality of Life in Post Massive Weight Loss Body Contouring Patients  

Microsoft Academic Search

Objective: Because post-bariatric surgery patients undergo massive weight loss, the resulting skin excess can lead to both functional problems and profound dissatisfaction with appearance. Correcting skin excess could improve all these corollaries, including body image. Presently, few data are available documenting body image and weight-related quality of life in this population.Research Methods and Procedures: Eighteen patients who underwent both bariatric

Angela Y. Song; J. Peter Rubin; Veena Thomas; Jason R. Dudas; Kacey G. Marra; Madelyn H. Fernstrom

2006-01-01

180

Transfer patient imaging: current status, review of the literature, and the Harborview experience.  

PubMed

Patients transferred for higher levels of care often arrive with medical imaging from the outside facility, with or without accompanying radiology reports. The handling of pretransfer studies by receiving radiologists introduces several concerns regarding resource utilization, medicolegal risk, and technical quality control. The authors review the current status of transfer patient imaging, with an emphasis on the role of the receiving emergency radiologist. Practice solutions developed at the authors' level I trauma center are described. PMID:23415656

McNeeley, Michael F; Gunn, Martin L; Robinson, Jeffrey D

2013-05-01

181

Usefulness of Medium-Energy Collimator for Sentinel Node Lymphoscintigraphy Imaging in Breast Cancer Patients  

Microsoft Academic Search

This study was performed to investigate the usefulness of a general-purpose medium-energy (ME) collimator for the accu- rate localization of the sentinel lymph node (SLN) in breast cancer patients. Methods: We compared phantom images and lymphoscintigraphy images obtained under different conditions for a patient with breast cancer. Comparisons were performed between 2 cameras, between a low-energy high-resolution (LEHR) collimator and

Hiroyuki Tsushima; Teruhiko Takayama; Takashi Yamanaga; Hiroto Kizu; Yoshihiro Shimonishi; Kazuhisa Kosakai; Atsushi Noguchi; Masahisa Onoguchi

182

The expanded very large array  

NASA Astrophysics Data System (ADS)

The Expanded Very Large Array (EVLA) is an international project to improve the scientific capabilities of the Very Large Array (VLA), an aperture synthesis radio telescope consisting of 27, 25-meter diameter antennas distributed in a Y-shaped configuration on the Plains of San Augustin in west-central New Mexico. The EVLA's major science themes include measuring the strength and topology of magnetic fields, enabling unbiased surveys and imaging of dust-shrouded objects that are obscured at other wavelengths, enabling rapid response to and imaging of rapidly evolving transient sources, and tracking the formation and evolution of objects in the universe. The EVLA's primary technical elements include new or upgraded receivers for continuous frequency coverage from 1 to 50 GHz, new local oscillator, intermediate frequency, and wide bandwidth data transmission systems to carry signals with 16 GHz total bandwidth from each antenna, and a new digital correlator with the capability to process this bandwidth with an unprecedented number of frequency channels for an imaging array. The project also includes a new monitor and control system and new software that will provide telescope ease of use. The project was started in 2001 and is on schedule and within budget. Scientific observations with the new correlator started in March 2010. The structural modifications that convert the VLA antennas to the EVLA design were completed in May 2010. The project will be complete in December 2012 when the last receiver will be installed on an antenna.

McKinnon, Mark; Perley, Rick; Jackson, Jim; Butler, Bryan; Rupen, Michael; Clark, Barry

2010-07-01

183

Gd-DTPA-Enhanced MR Imaging of the Brain in Patients with Meningitis: Comparison with CT  

Microsoft Academic Search

Plain and Gd-DTPA-enhanced MR images of the brain were obtained in 18 consecutive patients with meningitis (eight with tuberculous, five with bacterial, three with viral, and two with fungal infections); the MR images were compared with CT scans. MR images were obtained on a 2.O-T superconducting unit with both Ti- and T2-weighted pulse sequences before injectionand with a TI-weighted sequence

Kee Hyun Chang; Moon Hee Han; Jae Kyu Roh; Man Chung Han; Chu-Wan Kim

184

Clinical decision support for imaging in the era of the Patient Protection and Affordable Care Act.  

PubMed

Imaging clinical decision support (CDS) systems provide evidence for or against imaging procedures ordered within a computerized physician order entry system at the time of the image order. Depending on the pertinent clinical history provided by the ordering clinician, CDS systems can optimize imaging by educating providers on appropriate image order entry and by alerting providers to the results of prior, potentially relevant imaging procedures, thereby reducing redundant imaging. The American Recovery and Reinvestment Act (ARRA) has expedited the adoption of computerized physician order entry and CDS systems in health care through the creation of financial incentives and penalties to promote the "meaningful use" of health IT. Meaningful use represents the latest logical next step in a long chain of legislation promoting the areas of appropriate imaging utilization, accurate reporting, and IT. It is uncertain if large-scale implementation of imaging CDS will lead to improved health care quality, as seen in smaller settings, or to improved patient outcomes. However, imaging CDS enables the correlation of existing imaging evidence with outcome measures, including morbidity, mortality, and short-term imaging-relevant management outcomes (eg, biopsy, chemotherapy). The purposes of this article are to review the legislative sequence relevant to imaging CDS and to give guidance to radiology practices focused on quality and financial performance improvement during this time of accelerating regulatory change. PMID:23206649

Zafar, Hanna M; Mills, Angela M; Khorasani, Ramin; Langlotz, Curtis P

2012-12-01

185

MR imaging of acute right lower quadrant pain in pregnant and nonpregnant patients.  

PubMed

The use of magnetic resonance (MR) imaging in the evaluation of acute abdominal pain is increasing, particularly in those circumstances where computed tomography (CT) is not desirable (eg, pregnancy, allergy to iodinated contrast material). Although ultrasonography (US) is considered the imaging study of choice for evaluation of abdominal pain in pregnant patients, MR imaging is a valuable adjunct to US in evaluation of pregnant patients with acute right lower quadrant (RLQ) pain who have inconclusive US results. MR imaging is also frequently used in patients with renal failure, in whom the use of iodinated contrast material is contraindicated, as well as in cases where CT results are inconclusive. In patients with acute RLQ pain, the breadth of abnormalities visible at MR imaging is very broad, with pathologic conditions potentially originating from multiple organ systems, but most commonly from the gastrointestinal and genitourinary systems. MR imaging is an excellent imaging modality for evaluation of RLQ pain and should be strongly considered in those patients in whom use of iodinated contrast media or radiation is not desirable. PMID:17495289

Pedrosa, Ivan; Zeikus, Eric A; Levine, Deborah; Rofsky, Neil M

2007-01-01

186

Imaging the pregnant patient for nonobstetric conditions: algorithms and radiation dose considerations.  

PubMed

Use of diagnostic imaging studies for evaluation of pregnant patients with medical conditions not related to pregnancy poses a persistent and recurring dilemma. Although a theoretical risk of carcinogenesis exists, there are no known risks for development of congenital malformations or mental retardation in a fetus exposed to ionizing radiation at the levels typically used for diagnostic imaging. An understanding of the effects of ionizing radiation on the fetus at different gestational stages and the estimated exposure dose received by the fetus from various imaging modalities facilitates appropriate choices for diagnostic imaging of pregnant patients with nonobstetric conditions. Other aspects of imaging besides radiation (ie, contrast agents) also carry potential for fetal injury and must be taken into consideration. Imaging algorithms based on a review of the current literature have been developed for specific nonobstetric conditions: pulmonary embolism, acute appendicitis, urolithiasis, biliary disease, and trauma. Imaging modalities that do not use ionizing radiation (ie, ultrasonography and magnetic resonance imaging) are preferred for pregnant patients. If ionizing radiation is used, one must adhere to the principle of using a dose that is as low as reasonably achievable after a discussion of risks versus benefits with the patient. PMID:18025513

Patel, Shital J; Reede, Deborah L; Katz, Douglas S; Subramaniam, Raja; Amorosa, Judith K

2007-01-01

187

Fast Monte Carlo Simulation for Patient-specific CT\\/CBCT Imaging Dose Calculation  

Microsoft Academic Search

Recently, X-ray imaging dose from computed tomography (CT) or cone beam CT (CBCT) scans has become a serious concern. Patient-specific imaging dose calculation has been proposed for the purpose of dose management. While Monte Carlo (MC) dose calculation can be quite accurate for this purpose, it suffers from low computational efficiency. In response to this problem, we have successfully developed

Xun Jia; Hao Yan; Xuejun Gu; Steve B. Jiang

2011-01-01

188

Fast Monte Carlo simulation for patient-specific CT\\/CBCT imaging dose calculation  

Microsoft Academic Search

X-ray imaging dose from computed tomography (CT) or cone beam CT (CBCT) scans has become a serious concern. Patient-specific imaging dose calculation has been proposed for the purpose of dose management. While Monte Carlo (MC) dose calculation can be quite accurate for this purpose, it suffers from low computational efficiency. In response to this problem, we have successfully developed a

Xun Jia; Hao Yan; Xuejun Gu; Steve B Jiang

2012-01-01

189

The Role of Public Relations for Image Creating in Health Services: A Sample Patient Satisfaction Survey  

Microsoft Academic Search

This study discusses the role of public relations for image creating in health services. Hospitals require public relations activities to distinguish them from competitors, provide bidirectional communication between the society and the hospital, and assist to create of a strong hospital image and culture. A satisfaction survey was conducted on 264 patients who have received health services at Maltepe University

Yalçïn Kirdar

2008-01-01

190

Multimode C-arm fluoroscopy, tomosynthesis, and cone-beam CT for image-guided interventions: from proof of principle to patient protocols  

NASA Astrophysics Data System (ADS)

High-performance intraoperative imaging is essential to an ever-expanding scope of therapeutic procedures ranging from tumor surgery to interventional radiology. The need for precise visualization of bony and soft-tissue structures with minimal obstruction to the therapy setup presents challenges and opportunities in the development of novel imaging technologies specifically for image-guided procedures. Over the past ~5 years, a mobile C-arm has been modified in collaboration with Siemens Medical Solutions for 3D imaging. Based upon a Siemens PowerMobil, the device includes: a flat-panel detector (Varian PaxScan 4030CB); a motorized orbit; a system for geometric calibration; integration with real-time tracking and navigation (NDI Polaris); and a computer control system for multi-mode fluoroscopy, tomosynthesis, and cone-beam CT. Investigation of 3D imaging performance (noise-equivalent quanta), image quality (human observer studies), and image artifacts (scatter, truncation, and cone-beam artifacts) has driven the development of imaging techniques appropriate to a host of image-guided interventions. Multi-mode functionality presents a valuable spectrum of acquisition techniques: i.) fluoroscopy for real-time 2D guidance; ii.) limited-angle tomosynthesis for fast 3D imaging (e.g., ~10 sec acquisition of coronal slices containing the surgical target); and iii.) fully 3D cone-beam CT (e.g., ~30-60 sec acquisition providing bony and soft-tissue visualization across the field of view). Phantom and cadaver studies clearly indicate the potential for improved surgical performance - up to a factor of 2 increase in challenging surgical target excisions. The C-arm system is currently being deployed in patient protocols ranging from brachytherapy to chest, breast, spine, and head and neck surgery.

Siewerdsen, J. H.; Daly, M. J.; Bachar, G.; Moseley, D. J.; Bootsma, G.; Brock, K. K.; Ansell, S.; Wilson, G. A.; Chhabra, S.; Jaffray, D. A.; Irish, J. C.

2007-03-01

191

CT imaging features of obturator prostheses in patients following palatectomy or maxillectomy.  

PubMed

Palatal tumors are often treated with palatectomy or maxillectomy. The resulting surgical defect produces an oroantral communication. An obturator is a removable prosthesis used to close the palatal or maxillectomy defect. Fifteen patients who had undergone palatectomy or maxillectomy for carcinoma and subsequent obturator prosthesis placement were retrospectively studied. Obturators were characterized by Hounsfield units and were subdivided into 3 CT imaging groups: either hyperattenuated, hollow (air-containing), or heterogeneous (isoattenuated to hyperattenuated with internal foci of air). Eight patients had hyperattenuated obturators either representing acrylic resin or Trusoft. Four patients had hollow obturators also composed of acrylic resin or Trusoft. Three patients had heterogeneous obturators, which were composed of only Trusoft. The postoperative imaging of patients treated for palatal or maxillary tumors can be complicated by the presence of obturator prostheses. The intent of this article was to familiarize the reader with the CT imaging features of obturator prostheses. PMID:21799037

Kumar, V A; Hofstede, T M; Ginsberg, L E

2011-01-01

192

Coping and self-image in patients with symptoms attributed to indoor environment.  

PubMed

This study investigated self-image and coping ability in a group of patients with symptoms from indoor environment. A follow-up questionnaire was sent to 239 patients previously referred with nonspecific building-related symptoms at University Hospital in Umeå, Sweden. One hundred seventy-four women and 14 men answered and the patient group rated their self-image as more spontaneous, more positive, and less negative than a control group. The patient group rated higher on the cognitive scale in the Coping Resources Inventory (CRI) than the control group. The female patients had an increased risk of not being able to work associated with a low score on negative self-image. The authors conclude that certain personality traits may be potential risk factors that increase the probability of encountering and experiencing stressful work situations. The resulting stress may increase workers' susceptibility to indoor environment exposure. PMID:23566321

Edvardsson, B; Bergdahl, J; Eriksson, N; Stenberg, B

2013-01-01

193

Modeling Cardiovascular Anatomy from Patient-Specific Imaging  

NASA Astrophysics Data System (ADS)

The importance of modern imaging techniques for capturing detailed structural information of a biological system cannot be understated. Unfortunately images do not reveal the "full functional story" and a spatially realistic computer model is often necessary for a comprehensive understanding of the complicated structural and physiological properties of the biological system's entities under investigation [1]. Deeper insights into structure-to-function relationships of different entities is achieved via finite element simulations of the modeled biomedical process. A 3D (three dimensional) finite element meshed computer model of the biological system is therefore a first step to perform such simulations.

Bajaj, Chandrajit; Goswami, Samrat

194

Muscle Hemangiomatosis Presenting as a Severe Feature in a Patient with the Pten Mutation: Expanding the Phenotype of Vascular Malformations in Bannayan-Riley-Ruvalcaba Syndrome  

PubMed Central

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare autosomal, dominantly-inherited, hamartoma syndrome with distinct phenotypic features. Mutations in the PTEN gene have been identified in PTEN hamartoma tumor syndromes. Our aim was to determine the correlation of phenotype-genotype relationships in a BRRS case. We have evaluated a PTEN mutation in a patient with vascular anomalies and the phenotypic findings of BRRS. We described an 8-year-old girl with the clinical features of BRRS, specifically with vascular anomalies. The mutation in the PTEN gene was identified by DNA sequencing. In our patient, we defined a de novo nonsense R335X (c.1003 C>T) mutation in exon 8, which results in a premature termination codon. Due to vascular anomalies and hemangioma, the patient’s left leg was amputated 1 year after the hemangioma diagnosis. Bannayan - Riley - Ruvalcaba syndrome patients with macrocephaly and vascular anomalies should be considered for PTEN mutation analysis and special medical care.

Soysal, Y; Acun, T; Lourenco, CM; Marques, W; Yak?c?er, MC

2012-01-01

195

Sequential treatment with ipilimumab and BRAF inhibitors in patients with metastatic melanoma: data from the Italian cohort of the ipilimumab expanded access program.  

PubMed

Of 93 patients with pretreated, BRAF(V600) mutation-positive advanced melanoma who received vemurafenib or dabrafenib before (n = 45) or after (n = 48) treatment with ipilimumab 3 mg/kg, median overall survival (mOS) from first treatment was 9.9 and 14.5 months, respectively. Among patients treated with a BRAF inhibitor first, mOS from the end of BRAF inhibition was 1.2 months for those who did not complete ipilimumab treatment as per protocol, compared with 12.7 months for those who did (p < .001). Prospective, randomized studies are required to determine the optimal sequencing of ipilimumab and BRAF inhibitors in patients with BRAF-mutated metastatic melanoma. PMID:24484235

Ascierto, Paolo Antonio; Simeone, Ester; Sileni, Vanna Chiarion; Del Vecchio, Michele; Marchetti, Paolo; Cappellini, Gian Carlo Antonini; Ridolfi, Ruggero; de Rosa, Francesco; Cognetti, Francesco; Ferraresi, Virginia; Testori, Alessandro; Queirolo, Paola; Bernengo, Maria Grazia; Guida, Michele; Galli, Luca; Mandalà, Mario; Cimminiello, Carolina; Rinaldi, Gaetana; Carnevale-Schianca, Fabrizio; Maio, Michele

2014-05-01

196

Prevalence of microdeletion 22q11 in patients with hypernasal speech due to velopharyngeal insufficiency: Expanded phenotype and clinical comparison to nondeletion  

SciTech Connect

Microdeletion 22q11.2 has been reported as a frequent ethiology of both velocardiofacial (VCF) and DiGeorge syndromes. We have studied the prevalence of microdeletion 22q11 in a group of patients ascertained through a Speech and Language clinic presenting with (1) velopharyngeal insufficiency (VPI) and (2) difficultly in school. Growth parameters were measured, and facies were scored for features of VCF. Microdeletions were detected at locus D22S75 by FISH with probe N25 (Oncor), and at 22q11.2 with high resolution banding analysis (HRB). One child with typical VCF facies was considered to have a deletion at 22q11 with HRB, but is not deleted with N25, indicating that N25 may not detect all deletion patients. An additional 8/30 children tested to date were deleted with the N25 probe. Heart defects were present in only 2/8 deletion patients: VSD/ASD and PS/AS. One N25 deletion patient was atypica; he has a tall, lanky habitus (height = 90%), and facies not characteristic of CVF. As expected, there is a trend to lower head size, smaller ear size, and more typical facies in deletion patients; however, four of the nondeletion patients also had a clinical diagnosis of VCF. Medially displaced carotid arteries were present in both groups, which is therefore not a diagnostic feature of microdeletion 22q11. Our findings indicate that the microdeletion 22q11 is frequent (26% in this series) in a population with VPI, even when not selected for typical facies. We believe this series supports the view that microdeletion 22q11 has a broader clinical phenotype than previously recognized.

Siegel-Bartelt, J.; Cytrynbaum, C.; Witzel, M.A.; Teshima, I.E. [Univ. of Toronto, Ontario (Canada)

1994-09-01

197

Cardiac electrophysiological activation pattern estimation from images using a patient-specific database of synthetic image sequences.  

PubMed

While abnormal patterns of cardiac electrophysiological activation are at the origin of important cardiovascular diseases (e.g., arrhythmia, asynchrony), the only clinically available method to observe detailed left ventricular endocardial surface activation pattern is through invasive catheter mapping. However, this electrophysiological activation controls the onset of the mechanical contraction; therefore, important information about the electrophysiology could be deduced from the detailed observation of the resulting motion patterns. In this paper, we present the study of this inverse cardiac electrokinematic relationship. The objective is to predict the activation pattern knowing the cardiac motion from the analysis of cardiac image sequences. To achieve this, we propose to create a rich patient-specific database of synthetic time series of the cardiac images using simulations of a personalized cardiac electromechanical model, in order to study this complex relationship between electrical activity and kinematic patterns in the context of this specific patient. We use this database to train a machine-learning algorithm which estimates the depolarization times of each cardiac segment from global and regional kinematic descriptors based on displacements or strains and their derivatives. Finally, we use this learning to estimate the patient’s electrical activation times using the acquired clinical images. Experiments on the inverse electrokinematic learning are demonstrated on synthetic sequences and are evaluated on clinical data with promising results. The error calculated between our prediction and the invasive intracardiac mapping ground truth is relatively small (around 10 ms for ischemic patients and 20 ms for nonischemic patient). This approach suggests the possibility of noninvasive electrophysiological pattern estimation using cardiac motion imaging. PMID:24058008

Prakosa, Adityo; Sermesant, Maxime; Allain, Pascal; Villain, Nicolas; Rinaldi, C Aldo; Rhode, Kawal; Razavi, Reza; Delingette, Hervé; Ayache, Nicholas

2014-02-01

198

The reproductive outcome of female patients with myotonic dystrophy type 1 (DM1) undergoing PGD is not affected by the size of the expanded CTG repeat tract  

Microsoft Academic Search

Purpose  This study aims to analyze the relationship between trinucleotide repeat length and reproductive outcome in a large cohort\\u000a of DM1 patients undergoing ICSI and PGD.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Prospective cohort study. The effect of trinucleotide repeat length on reproductive outcome per patient was analyzed using\\u000a bivariate analysis (T-test) and multivariate analysis using Kaplan-Meier and Cox regression analysis.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Between 1995 and 2005, 205 cycles

Willem Verpoest; Sara Seneca; Marjan De Rademaeker; Karen Sermon; Martine De Rycke; Michel De Vos; Patrick Haentjens; Paul Devroey; Ingeborg Liebaers

2010-01-01

199

Cardiovascular Imaging in Patients with Chronic Kidney Disease  

Microsoft Academic Search

Cardiovascular disease is highly prevalent in chronic kidney disease and has been associated with increased morbidity and mortality. Several morphological and functional tests are available to assess the cardiovascular system. Since structural and functional cardiovascular abnormalities have prognostic implications, their identification may become crucial for the implementation of effective preventive and therapeutic strategies. We review the most frequently used imaging

Cristina Karohl; Paolo Raggi

2011-01-01

200

Method and system for the diagnosis of disease using retinal image content and an archive of diagnosed human patient data  

DOEpatents

A method for diagnosing diseases having retinal manifestations including retinal pathologies includes the steps of providing a CBIR system including an archive of stored digital retinal photography images and diagnosed patient data corresponding to the retinal photography images, the stored images each indexed in a CBIR database using a plurality of feature vectors, the feature vectors corresponding to distinct descriptive characteristics of the stored images. A query image of the retina of a patient is obtained. Using image processing, regions or structures in the query image are identified. The regions or structures are then described using the plurality of feature vectors. At least one relevant stored image from the archive based on similarity to the regions or structures is retrieved, and an eye disease or a disease having retinal manifestations in the patient is diagnosed based on the diagnosed patient data associated with the relevant stored image(s).

Tobin, Kenneth W; Karnowski, Thomas P; Chaum, Edward

2013-08-06

201

Congenital pulmonary malformations in pediatric patients: review and update on etiology, classification, and imaging findings.  

PubMed

Congenital pulmonary malformations represent a heterogeneous group of developmental disorders affecting the lung parenchyma, the arterial supply to the lung, and the lung's venous drainage. In both asymptomatic and symptomatic pediatric patients with congenital pulmonary malformations, the diagnosis of such malformations usually requires imaging evaluation, particularly in cases of surgical lesions for preoperative assessment. The goal of this article is to review the current imaging techniques for evaluating congenital pulmonary malformations and their characteristic imaging findings, which can allow differentiation among various congenital pulmonary malformations in pediatric patients. PMID:21889015

Lee, Edward Y; Dorkin, Henry; Vargas, Sara O

2011-09-01

202

Clinical Application of 3D-FIESTA Image in Patients with Unilateral Inner Ear Symptom  

PubMed Central

Background and Objectives Unilateral auditory dysfunction such as tinnitus and hearing loss could be a warning sign of a retrocochlear lesion. Auditory brainstem response (ABR) and internal auditory canal magnetic resonance image (MRI) are suggested as novel diagnostic tools for retrocochlear lesions. However, the high cost of MRI and the low sensitivity of the ABR test could be an obstacle when assessing patients with unilateral ear symptoms. The purpose of this study was to introduce the clinical usefulness of three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) MRI in patients with unilateral ear symptoms. Subjects and Methods Two hundred and fifty-three patients with unilateral tinnitus or unilateral hearing loss who underwent 3D-FIESTA temporal bone MRI as a screening test were enrolled. We reviewed the abnormal findings in the 3D-FIESTA images and ear symptoms using the medical records. Results In patients with unilateral ear symptoms, 51.0% of the patients had tinnitus and 32.8% patients were assessed to have sudden sensory neural hearing loss. With 3D-FIESTA imaging, twelve patients were diagnosed with acoustic neuroma, four with enlarged vestibular aqueduct syndrome, and two with posterior inferior cerebellar artery aneurysm. Inner ear anomalies and vestibulocochlear nerve aplasia could be diagnosed with 3D-FIESTA imaging. Conclusions 3D-FIESTA imaging is a highly sensitive method for the diagnosis of cochlear or retrocochlear lesions. 3D-FIESTA imaging is a useful screening tool for patients with unilateral ear symptoms.

Oh, Jae Ho; Chung, Jae Ho; Min, Hyun Jung; Cho, Seok Hyun; Park, Chul Won

2013-01-01

203

High response rate to bortezomib with or without dexamethasone in patients with relapsed or refractory multiple myeloma: results of a global phase 3b expanded access program.  

PubMed

Phase 2 trials have demonstrated that bortezomib +/- dexamethasone is safe and effective in relapsed multiple myeloma (MM). In this multicentre, open-label, phase 3b trial, 638 patients with relapsed or refractory MM (median 3 prior therapies) received bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11 of a maximum of eight 3-week cycles (median 5 cycles). Dexamethasone 20 mg/d was added the day of and day after each bortezomib dose for progressive disease after > or =2 cycles or for stable disease after > or =4 cycles. Responses were assessed based on M-protein changes. Overall response rate was 67%, including 11% complete (100% M-protein reduction), 22% very good partial (75-99% reduction), 18% partial (50-74% reduction), and 16% minimal response (25-49% reduction). Dexamethasone was added in 208 patients (33%), of whom 70 (34%) showed improved response. Median time to best response of minimal response or better was 84 d. Most common grade 3/4 adverse events were thrombocytopenia (39%), neutropenia (16%), anaemia (12%), diarrhoea (7%), and peripheral neuropathy (6%). Neuropathy (any grade) was seen in 25% of the patients and led to discontinuation in 5%. Bortezomib, alone and combined with dexamethasone, is safe and effective in heavily pretreated patients with relapsed or refractory MM. PMID:19036114

Mikhael, Joseph R; Belch, Andrew R; Prince, H Miles; Lucio, Maria Nambo; Maiolino, Angelo; Corso, Alessandro; Petrucci, Maria Teresa; Musto, Pellegrino; Komarnicki, Mieczyslaw; Stewart, A Keith

2009-01-01

204

Disparities in imaging utilization for acute ischemic stroke based on patient insurance status.  

PubMed

OBJECTIVE. Previous studies have shown socioeconomic disparities in imaging utilization for both acute and chronic diseases. We studied a nationwide database to determine whether insurance-based disparities exist in the utilization of imaging for acute ischemic stroke. MATERIALS AND METHODS. Inpatients with a primary diagnosis of acute ischemic stroke from November 2005 through December 2011 were identified from the Perspective database. Patients were stratified into four groups according to insurance status as follows: uninsured, Medicaid, Medicare, and private insurance. Utilization rates of head CT, perfusion CT, head MRI, noninvasive head angiography (including head CT angiography [CTA] and head MR angiography [MRA]), noninvasive neck angiography (including neck CTA and neck MRA), carotid ultrasound, and echocardiography were compared using a chi-square test. A multivariable logistic regression model adjusting for potential confounding variables was fit to determine the association between insurance status and imaging utilization. RESULTS. A total of 210,212 patients were included in this study: 10,396 patients (5.0%) were uninsured, 14,243 patients (6.8%) had Medicaid, 153,209 patients (72.9%) had Medicare, and 32,364 patients (15.4%) had private insurance. Even after we had controlled for confounding variables, significant disparities existed in imaging utilization. Compared with patients with private insurance, uninsured patients had significantly lower odds of noninvasive head angiography (odds ratio [OR] = 0.78, 95% CI = 0.74-0.81, p < 0.0001), neck angiography (OR = 0.79, 95% CI = 0.76-0.83, p < 0.0001), and head MRI (OR = 0.77, 95% CI = 0.74-0.81, p < 0.0001). The same was true for Medicaid and Medicare patients. CONCLUSION. Disparities exist in the utilization of noninvasive head and neck imaging, MRI, and echocardiography for patients with acute ischemic stroke based on patient insurance status. More research is needed to understand these disparities. PMID:25055273

Brinjikji, Waleed; El-Sayed, Abdulrahman M; Rabinstein, Alejandro A; McDonald, Jennifer S; Cloft, Harry J

2014-08-01

205

Patent foramen ovale size and embolic brain imaging findings among patients with ischemic stroke  

Microsoft Academic Search

Background and Purpose—Although the cause of stroke among patients with patent foramen ovale (PFO) may be due to paradoxical cerebral embolism (PCE), this mechanism is often difficult to prove. The aim of our study was to evaluate the association between brain imaging findings suggestive of embolism and PFO among ischemic stroke patients. Methods—As part of the Northern Manhattan Stroke Study,

Michaela M. Steiner; Di Tullio; Tanja Rundek; Robert Gan; Xun Chen; Chiara Liguori; Michael Brainin; Shunichi Homma; Ralph L. Sacco

1998-01-01

206

Magnetic resonance imaging findings of internal derangement and effusion in patients with unilateral temporomandibular joint pain  

Microsoft Academic Search

Objectives: The purpose of this study was to investigate the relationship between the presence of temporomandibular joint (TMJ) pain and the magnetic resonance (MR) imaging findings of internal derangement (ID) and effusion. Study Design: The study was comprised of 41 consecutive patients with TMJ pain. Criteria for including a patient were report of unilateral pain near the TMJ, with the

Ansgar Rudisch; Katharina Innerhofer; Stefan Bertram; Rüdiger Emshoff

2001-01-01

207

Magnetic resonance imaging compared to echocardiography to assess left ventricular mass in the hypertensive patient  

Microsoft Academic Search

Echocardiography (ECHO) is useful to document changes in left ventricular mass (LVM) in groups of patients, but may be too variable for use in the individual patient. Magnetic resonance imaging (MRI) may be a more precise and reliable method to quantify the mass of the left ventricle. This study reports the accuracy, precision, and reliability of LVM estimates by MRI

Peter B. Bottini; Albert A. Carr; L. Michael Prisant; Fred W. Flickinger; Jerry D. Allison; John S. Gottdiener

1995-01-01

208

F18 EF5 PET/CT Imaging in Patients with Brain Metastases from Breast Cancer.  

National Technical Information Service (NTIS)

The aim of this study is to estimate the degree of residual hypoxia after whole brain radiation therapy in patients with brain metastases from breast cancer as quantified by F18 EF5 PET/CT imaging. We enrolled two patients on this study who after completi...

L. Lin

2012-01-01

209

Investigation of gamma knife image registration errors resulting from misalignment between the patient and the imaging axis.  

PubMed

The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comfort. Results equally apply to magnetic resonance imaging. Seven 0.5 mm diameter CT-visible spheres were rigidly mounted to a string tied tightly at each end to diagonally opposite posts attached to a Leksell stereotactic frame. A standard CT fiducial box was applied to the frame in the usual clinical manner. A baseline CT scan (1 mm slice thickness) was obtained with the fiducial box perfectly aligned with the scanner axis. After localization of the image set, the (x,y,z) coordinate of the center of each sphere was recorded. Repeat CT scans with varying fiducial box misalignments with the imaging axis were subsequently obtained. The mean difference between the base line and the respective coordinates in misaligned geometries was approximately 0.2 mm (sigma=0.2 mm), well within the accuracy of the image sets and the delivery of radiosurgery with the Gamma Knife. PMID:16696470

Cernica, George; Wang, Zhou; Malhotra, Harish; de Boer, Steven; Podgorsak, Matthew B

2006-04-01

210

Investigation of Gamma Knife image registration errors resulting from misalignment between the patient and the imaging axis  

SciTech Connect

The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comfort. Results equally apply to magnetic resonance imaging. Seven 0.5 mm diameter CT-visible spheres were rigidly mounted to a string tied tightly at each end to diagonally opposite posts attached to a Leksell stereotactic frame. A standard CT fiducial box was applied to the frame in the usual clinical manner. A baseline CT scan (1 mm slice thickness) was obtained with the fiducial box perfectly aligned with the scanner axis. After localization of the image set, the (x,y,z) coordinate of the center of each sphere was recorded. Repeat CT scans with varying fiducial box misalignments with the imaging axis were subsequently obtained. The mean difference between the base line and the respective coordinates in misaligned geometries was approximately 0.2 mm ({sigma}=0.2 mm), well within the accuracy of the image sets and the delivery of radiosurgery with the Gamma Knife.

Cernica, George; Wang Zhou; Malhotra, Harish; Boer, Steven de; Podgorsak, Matthew B. [Department of Physics, State University of New York, Buffalo, New York 14260 (United States) and Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States); Department of Radiation Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263 (United States)

2006-04-15

211

Noninvasive imaging of the high frequency brain activity in focal epilepsy patients.  

PubMed

High-frequency (HF) activity represents a potential biomarker of the epileptogenic zone in epilepsy patients, the removal of which is considered to be crucial for seizure-free surgical outcome. We proposed a high frequency source imaging (HFSI) approach to noninvasively image the brain sources of the scalp-recorded HF EEG activity. Both computer simulation and clinical patient data analysis were performed to investigate the feasibility of using the HFSI approach to image the sources of HF activity from noninvasive scalp EEG recordings. The HF activity was identified from high-density scalp recordings after high-pass filtering the EEG data and the EEG segments with HF activity were concatenated together to form repetitive HF activity. Independent component analysis was utilized to extract the components corresponding to the HF activity. Noninvasive EEG source imaging using realistic geometric boundary element head modeling was then applied to image the sources of the pathological HF brain activity. Five medically intractable focal epilepsy patients were studied and the estimated sources were found to be concordant with the surgical resection or intracranial recordings of the patients. The present study demonstrates, for the first time, that source imaging from the scalp HF activity could help to localize the seizure onset zone and provide a novel noninvasive way of studying the epileptic brain in humans. This study also indicates the potential application of studying HF activity in the presurgical planning of medically intractable epilepsy patients. PMID:24845275

Lu, Yunfeng; Worrell, Gregory A; Zhang, Huishi Clara; Yang, Lin; Brinkmann, Benjamin; Nelson, Cindy; He, Bin

2014-06-01

212

Abnormal brain magnetic resonance imaging in two patients with Smith-Magenis syndrome.  

PubMed

Smith-Magenis syndrome (SMS) is a clinically recognizable contiguous gene syndrome ascribed to an interstitial deletion in chromosome 17p11.2. Seventy percent of SMS patients have a common deletion interval spanning 3.5 megabases (Mb). Clinical features of SMS include characteristic mild dysmorphic features, ocular anomalies, short stature, brachydactyly, and hypotonia. SMS patients have a unique neurobehavioral phenotype that includes intellectual disability, self-injurious behavior and severe sleep disturbance. Little has been reported in the medical literature about anatomical brain anomalies in patients with SMS. Here we describe two patients with SMS caused by the common deletion in 17p11.2 diagnosed using chromosomal microarray (CMA). Both patients had a typical clinical presentation and abnormal brain magnetic resonance imaging (MRI) findings. One patient had subependymal periventricular gray matter heterotopia, and the second had a thin corpus callosum, a thin brain stem and hypoplasia of the cerebellar vermis. This report discusses the possible abnormal MRI images in SMS and reviews the literature on brain malformations in SMS. Finally, although structural brain malformations in SMS patients are not a common feature, we suggest baseline routine brain imaging in patients with SMS in particular, and in patients with chromosomal microdeletion/microduplication syndromes in general. Structural brain malformations in these patients may affect the decision-making process regarding their management. © 2014 Wiley Periodicals, Inc. PMID:24788350

Maya, Idit; Vinkler, Chana; Konen, Osnat; Kornreich, Liora; Steinberg, Tamar; Yeshaya, Josepha; Latarowski, Victoria; Shohat, Mordechai; Lev, Dorit; Baris, Hagit N

2014-08-01

213

Simultaneous storage of patient information with medical images in the frequency domain.  

PubMed

Digital watermarking is a technique of hiding specific identification data for copyright authentication. Most of the medical images are compressed by joint photographic experts group (JPEG) standard for storage. The watermarking is adapted here for interleaving patient information with medical images during JPEG compression, to reduce storage and transmission overheads. The text data is encrypted before interleaving with images in the frequency domain to ensure greater security. The graphical signals are also interleaved with the image. The result of this work is tabulated for a specific example and also compared with the spatial domain interleaving. PMID:15313538

Acharya, Rajendra; Niranjan, U C; Iyengar, S S; Kannathal, N; Min, Lim Choo

2004-10-01

214

The Effect of Doxapram on Brain Imaging In Patients with Panic Disorder  

PubMed Central

Administration of doxapram hydrochloride, a respiratory stimulant, is experienced by panic disorder patients to be similar to panic attacks but has reduced emotional effect in normal volunteers thus providing a laboratory model of panic for functional imaging. Six panic patients and seven normal control subjects underwent positron emission tomography with 18F-deoxyglucose imaging after a single-blinded administration of either doxapram or a placebo saline solution. Saline and doxapram were administered on separate days in counterbalanced order. Patients showed a greater heart rate increase on doxapram from saline than controls, indicating differential response. On the saline placebo day, patients had greater prefrontal relative activity than controls. In response to doxapram, patients tended to decrease prefrontal activity more than controls, and increased cingulate gyrus and amygdala activity more than controls. This suggests that panic disorder patients activate frontal inhibitory centers less than controls which may lower the threshold for panic.

Garakani, Amir; Buchsbaum, Monte S.; Newmark, Randall E.; Goodman, Chelain; Aaronson, Cindy J.; Martinez, Jose M.; Torosjan, Yuliya; Chu, King-Wai; Gorman, Jack M.

2009-01-01

215

Imaging of Microglia in Patients with Neurodegenerative Disorders  

PubMed Central

Microglia constitute the main immune defense in the central nervous system. In response to neuronal injury, microglia become activated, acquire phagocytic properties, and release a wide range of pro-inflammatory mediators that are essential for the annihilation of the neuronal insult. Although the role of microglial activation in acute neuronal damage is well defined, the pathophysiological processes underlying destructive or protective role to neurons following chronic exposure to microglial activation is still a subject of debate. It is likely that chronic exposure induces detrimental effects by promoting neuronal death through the release of neurotoxic factors. Positron emission tomography (PET) imaging with the use of translocator protein (TSPO) radioligands provides an in vivo tool for tracking the progression and severity of neuroinflammation in neurodegenerative disease. TSPO expression is correlated to the extent of microglial activation and the measurement of TSPO uptake in vivo with PET is a useful indicator of active disease. Although understanding of the interaction between radioligands and TSPO is not completely clear, there is a wide interest in application of TSPO imaging in neurodegenerative disease. In this article, we aim to review the applications of in vivo microglia imaging in neurodegenerative disorders such as Parkinson’s disease, Huntington’s disease, Dementias, and Multiple Sclerosis.

Politis, Marios; Su, Paul; Piccini, Paola

2012-01-01

216

Correlations between multiple sclerosis functional composite, expanded disability status scale and health-related quality of life during and after treatment of relapses in patients with multiple sclerosis  

Microsoft Academic Search

The measurement of the clinical manifestations of multiple sclerosis (MS) is difficult. In the present study, we examined the changes in measurement of functions during and after pulse methylprednisolon (MP) treatment of MS exacerbations using the MSFC and EDSS. Correlation between multiple sclerosis quality of life (MSQoL)-54, EDSS and MSFC were studied. Thirty-six clinically definite MS patients were included in

Serkan Ozakbas; Inanc Cagiran; Burcu Ormeci; Egemen Idiman

2004-01-01

217

Clinical and molecular analysis of UAE fibrochondrogenesis patients expands the phenotype and reveals two COL11A1 homozygous null mutations.  

PubMed

Fibrochondrogenesis is documented to be a neonatally lethal rare recessively inherited disorder characterized by short-limbed skeletal dysplasia. Here we report two patients from two unrelated consanguineous Emirati families who have unexpectedly survived till the ages of 3 and 6 years. These patients show additional symptoms which include developmental delay, profound sensory-neural deafness, severe myopia and progressive severe skeletal abnormalities. Linkage of fibrochondrogenesis in the Emirati families to chromosome 1 has been established using homozygosity mapping confirming recent findings by Tompson et al. in 2010. Screening of the COL11A1 gene revealed two null homozygous mutations [c.4084C>T (p.R1362X) and c.3708+437T>G] in the aforementioned two families. The c.4084C>T mutation is predicted to introduce a stop codon at position Arg1362, whereas the c.3708+437T>G mutation causes the activation of an intronic pseudoexon between exons 48 and 49. This resulted in the insertion of 50 nucleotides into the mRNA. The carriers of these mutations display ocular defects with normal hearing. In conclusion, our data shall improve the overall understanding of fibrochondrogenesis especially in surviving homozygous patients and, at least partly, explain the phenotypic variability associated with COL11A1 gene mutations. PMID:21668896

Akawi, N A; Al-Gazali, L; Ali, B R

2012-08-01

218

Survival outcomes in patients with advanced non-small cell lung cancer treated with erlotinib: expanded access programme data from Belgium (the TRUST study).  

PubMed

Erlotinib has been shown to prolong progression-free (PFS) and overall survival (OS) in patients with advanced non-small cell lung cancer (NSCLC). We report here on effectiveness data on the subsample of 261 patients from 40 centres in Belgium involved in the TRUST study. Median age was 63 years. Most (69.0%) were male and current/former smokers (84.7%); with Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 (74.3%), stage IV disease (75.1%) and adenocarcinoma by histology (54.0%). Erlotinib was administered mainly as second- (47.1%) or third-line treatment (48.3%). Response rate was 6.5%; disease control rate 58.3%. Median PFS was 2.2 months. Better PS (P = 0.0384), stage IIIB disease (P = 0.0018) and presence of rash (P < 0.0001) were associated with longer PFS. OS rates at 1, 2 and 3 years were 26.4%, 10.9% and 6.4% respectively. Median OS was 5.9 months. Female gender (P = 0.007), better PS (P < 0.0001), stage IIIB disease (P = 0.0355) and presence of rash (P < 0.0001) were associated with longer OS. The findings confirm the therapeutic benefit of erlotinib in a broad range of patients in a sample from a country with a historically high lung cancer morbidity and mortality burden. Several determinants of PFS and OS are identified. PMID:24152297

Van Meerbeeck, J; Galdermans, D; Bustin, F; De Vos, L; Lechat, I; Abraham, I

2014-05-01

219

Spinocerebellar ataxia type 7 (SCA7): first report of a systematic neuropathological study of the brain of a patient with a very short expanded CAG-repeat.  

PubMed

Spinocerebellar ataxia type 7 (SCA7) represents a very rare and severe autosomal dominantly inherited cerebellar ataxia (ADCA). It belongs to the group of CAG-repeat or polyglutamine diseases with its underlying molecular genetical defect on chromosome 3p12-p21.1. Here, we performed a systematic study of the neuropathology on unconventional thick serial sections of the first available brain tissue of a genetically confirmed late-onset SCA7 patient with a very short CAG-repeat expansion. Along with myelin pallor of a variety of central nervous fiber tracts, we observed i) neurodegeneration in select areas of the cerebral cortex, and ii) widespread nerve cell loss in the cerebellum, thalamus, nuclei of the basal ganglia, and brainstem. In addition, upon immunocytochemical analysis using the anti-polyglutamine antibody 1C2, immunopositive neuronal intranuclear inclusions bodies (NI) were observed in all cerebellar regions, in all parts of the cerebral cortex, and in telencephalic and brainstem nuclei, irrespective of whether they underwent neurodegeneration. These novel findings provide explanations for a variety of clinical symptoms and paraclinical findings of both our and other SCA7 patients. Finally, our immunocytochemical analysis confirms previous studies which described the presence of NI in obviously degenerated brain and retinal regions as well as in apparently well-preserved brain regions and retina of SCA7 patients. PMID:16389941

Rüb, U; Brunt, E R; Gierga, K; Seidel, K; Schultz, C; Schöls, L; Auburger, G; Heinsen, H; Ippel, P F; Glimmerveen, W F; Wittebol-Post, D; Arai, K; Deller, T; de Vos, R A I

2005-10-01

220

Expanding maps, shrinking targets and hitting times  

NASA Astrophysics Data System (ADS)

We study the (metric) Diophantine approximation properties of uniformly expanding transformations and some non-uniformly expanding transformations, i.e. transformations T(x) with an associated countable (not necessarily finite) partition and a return time function R(x) (constant on the blocks of the partition) so that \\widehat{T}(x)=T^{R(x)}(x) is uniformly expanding, and we obtain Borel-Cantelli results on hitting times of shrinking targets. Our arguments do not require the so-called big image property for \\widehat{T} and our results contain most of the diversity of examples of slowly mixing systems. We also obtain, with related techniques, results for one-sided topological Markov chains over a countable alphabet with a Gibbs measure.

Fernández, J. L.; Melián, M. V.; Pestana, D.

2012-09-01

221

Recent advances in MRI technology: Implications for image quality and patient safety  

PubMed Central

Recent advances in MRI technology are presented, with emphasis on how this new technology impacts clinical operations (better image quality, faster exam times, and improved throughput). In addition, implications for patient safety are discussed with emphasis on the risk of patient injury due to either high local specific absorption rate (SAR) or large cumulative energy doses delivered during long exam times. Patient comfort issues are examined as well.

Sobol, Wlad T.

2012-01-01

222

Dose reduction and image quality optimizations in CT of pediatric and adult patients: phantom studies  

NASA Astrophysics Data System (ADS)

Multi-detector computed tomography (MDCT) can be used to easily and rapidly perform numerous acquisitions, possibly leading to a marked increase in the radiation dose to individual patients. Technical options dedicated to automatically adjusting the acquisition parameters according to the patient's size are of specific interest in pediatric radiology. A constant tube potential reduction can be achieved for adults and children, while maintaining a constant detector energy fluence. To evaluate radiation dose, the weighted CT dose index (CTDIw) was calculated based on the CT dose index (CTDI) measured using an ion chamber, and image noise and image contrast were measured from a scanned image to evaluate image quality. The dose-weighted contrast-to-noise ratio (CNRD) was calculated from the radiation dose, image noise, and image contrast measured from a scanned image. The noise derivative (ND) is a quality index for dose efficiency. X-ray spectra with tube voltages ranging from 80 to 140 kVp were used to compute the average photon energy. Image contrast and the corresponding contrast-to-noise ratio (CNR) were determined for lesions of soft tissue, muscle, bone, and iodine relative to a uniform water background, as the iodine contrast increases at lower energy (i.e., k-edge of iodine is 33 keV closer to the beam energy) using mixed water-iodine contrast normalization (water 0, iodine 25, 100, 200, and 1000 HU, respectively). The proposed values correspond to high quality images and can be reduced if only high-contrast organs are assessed. The potential benefit of lowering the tube voltage is an improved CNRD, resulting in a lower radiation dose and optimization of image quality. Adjusting the tube potential in abdominal CT would be useful in current pediatric radiography, where the choice of X-ray techniques generally takes into account the size of the patient as well as the need to balance the conflicting requirements of diagnostic image quality and radiation dose optimization.

Jeon, P.-H.; Lee, C.-L.; Kim, D.-H.; Lee, Y.-J.; Jeon, S.-S.; Kim, H.-J.

2014-03-01

223

Automatic Exudates Detection on Thai Diabetic Retinopathy Patients' Retinal Images  

Microsoft Academic Search

Diabetic retinopathy is a complication of diabetes that is caused by changes in the blood vessels of the retina. The symptom can blur or distort the patient's vision and are mainly cause of blindness. Exudates are one of the primary signs of diabetic retinopathy. Detection of exudates by ophthalmologists normally required pupil dilation using chemical solution which takes time and

Akara Sopharak; Bunyarit Uyyanonvara

2006-01-01

224

Education and Outreach for Breast Imaging and Breast Cancer Patients.  

National Technical Information Service (NTIS)

During the past year, we obtained lRB approval from the DOD to begin data collection in December, 2001. However, the practice of the Breast Health Center, where the study was planned, had changed. Because randomization of patients according to core biopsy...

D. M. Farria

2002-01-01

225

Magnetic resonance imaging for radiotherapy planning of brain cancer patients using immobilization and surface coils  

NASA Astrophysics Data System (ADS)

This study investigated the compatibility of a head and neck immobilization device with magnetic resonance imaging (MRI). The immobilization device is used to position a patient in the same way as when receiving a computed tomography (CT) scan for radiotherapy planning and radiation treatment. The advantage of using immobilization in MR is improved accuracy in CT/MR image registration enabling greater confidence in the delineation of structures. The main practical difficulty in using an immobilization device in MRI is that physical constraints make their use incompatible with head imaging coils. Within this paper we describe a method for MR imaging of the brain which allows the use of head and neck immobilization devices. By a series of image quality tests we obtained the same or better image quality as a multi-channel head coil.

Hanvey, S.; Glegg, M.; Foster, J.

2009-09-01

226

Expanding the Visibility of Women's Work: Policy Implications.  

ERIC Educational Resources Information Center

Social conceptualization and media images of women's work affect health and social policy formation. Nurses can expand the visibility of women's work and promote gender-sensitive policies within and outside the profession. (SK)

Messias, DeAnne K. Hilfinger; Regev, Hanna; Im, Eun-Ok; Spiers, Judith A.; Van, Paulina; Meleis, Afaf Ibrahim

1997-01-01

227

Imaging of Cerebral Blood Flow in Patients with Severe Traumatic Brain Injury in the Neurointensive Care  

PubMed Central

Ischemia is a common and deleterious secondary injury following traumatic brain injury (TBI). A great challenge for the treatment of TBI patients in the neurointensive care unit (NICU) is to detect early signs of ischemia in order to prevent further advancement and deterioration of the brain tissue. Today, several imaging techniques are available to monitor cerebral blood flow (CBF) in the injured brain such as positron emission tomography (PET), single-photon emission computed tomography, xenon computed tomography (Xenon-CT), perfusion-weighted magnetic resonance imaging (MRI), and CT perfusion scan. An ideal imaging technique would enable continuous non-invasive measurement of blood flow and metabolism across the whole brain. Unfortunately, no current imaging method meets all these criteria. These techniques offer snapshots of the CBF. MRI may also provide some information about the metabolic state of the brain. PET provides images with high resolution and quantitative measurements of CBF and metabolism; however, it is a complex and costly method limited to few TBI centers. All of these methods except mobile Xenon-CT require transfer of TBI patients to the radiological department. Mobile Xenon-CT emerges as a feasible technique to monitor CBF in the NICU, with lower risk of adverse effects. Promising results have been demonstrated with Xenon-CT in predicting outcome in TBI patients. This review covers available imaging methods used to monitor CBF in patients with severe TBI.

Rostami, Elham; Engquist, Henrik; Enblad, Per

2014-01-01

228

Advanced diffusion imaging sequences could aid assessing patients with focal cortical dysplasia and epilepsy?  

PubMed Central

Summary Malformations of cortical development (MCD), particularly focal cortical dysplasia (FCD), are a common cause of refractory epilepsy but are often invisible on structural imaging. NODDI (neurite orientation dispersion and density imaging) is an advanced diffusion imaging technique that provides additional information on tissue microstructure, including intracellular volume fraction (ICVF), a marker of neurite density. We applied this technique in 5 patients with suspected dysplasia to show that the additional parameters are compatible with the underlying disrupted tissue microstructure and could assist in the identification of the affected area. The consistent finding was reduced ICVF in the area of dysplasia. In one patient, an area of reduced ICVF and increased fibre dispersion was identified that was not originally seen on the structural imaging. The focal reduction in ICVF on imaging is compatible with previous iontophoretic data in surgical specimens, was more conspicuous than on other clinical or diffusion images (supported by an increased contrast-to-noise ratio) and more localised than on previous DTI studies. NODDI may therefore assist the clinical identification and localisation of FCD in patients with epilepsy. Future studies will assess this technique in a larger cohort including MRI negative patients.

Winston, Gavin P.; Micallef, Caroline; Symms, Mark R.; Alexander, Daniel C.; Duncan, John S.; Zhang, Hui

2014-01-01

229

An optically stimulated luminescence dosimeter for measuring patient exposure from imaging guidance procedures.  

PubMed

There is a growing interest in patient exposure resulting from an x-ray imaging procedure used in image-guided radiation therapy. This study explores a feasibility to use a commercially available optically stimulated luminescence (OSL) dosimeter, nanoDot, for estimating imaging radiation exposure to patients. The kilovoltage x-ray sources used for kV-cone-beam CT (CBCT) imaging acquisition procedures were from a Varian on-board imager (OBI) image system. An ionization chamber was used to determine the energy response of nanoDot dosimeters. The chamber calibration factors for x-ray beam quality specified by half-value layer were obtained from an Accredited Dosimetry Calibration Laboratory. The Monte Carlo calculated dose distributions were used to validate the dose distributions measured by using the nanoDot dosimeters in phantom and in vivo. The range of the energy correction factors for the nanoDot as a function of photon energy and bow-tie filters was found to be 0.88-1.13 for different kVp and bow-tie filters. Measurement uncertainties of nanoDot were approximately 2-4% after applying the energy correction factors. The tests of nanoDot placed on a RANDO phantom and on patient's skin showed consistent results. The nanoDot is suitable dosimeter for in vivo dosimetry due to its small size and manageable energy dependence. The dosimeter placed on a patient's skin has potential to serve as an experimental method to monitor and to estimate patient exposure resulting from a kilovoltage x-ray imaging procedure. Due to its large variation in energy response, nanoDot is not suitable to measure radiation doses resulting from mixed beams of megavoltage therapeutic and kilovoltage imaging radiations. PMID:23920245

Ding, George X; Malcolm, Arnold W

2013-09-01

230

An optically stimulated luminescence dosimeter for measuring patient exposure from imaging guidance procedures  

NASA Astrophysics Data System (ADS)

There is a growing interest in patient exposure resulting from an x-ray imaging procedure used in image-guided radiation therapy. This study explores a feasibility to use a commercially available optically stimulated luminescence (OSL) dosimeter, nanoDot, for estimating imaging radiation exposure to patients. The kilovoltage x-ray sources used for kV-cone-beam CT (CBCT) imaging acquisition procedures were from a Varian on-board imager (OBI) image system. An ionization chamber was used to determine the energy response of nanoDot dosimeters. The chamber calibration factors for x-ray beam quality specified by half-value layer were obtained from an Accredited Dosimetry Calibration Laboratory. The Monte Carlo calculated dose distributions were used to validate the dose distributions measured by using the nanoDot dosimeters in phantom and in vivo. The range of the energy correction factors for the nanoDot as a function of photon energy and bow-tie filters was found to be 0.88-1.13 for different kVp and bow-tie filters. Measurement uncertainties of nanoDot were approximately 2-4% after applying the energy correction factors. The tests of nanoDot placed on a RANDO phantom and on patient's skin showed consistent results. The nanoDot is suitable dosimeter for in vivo dosimetry due to its small size and manageable energy dependence. The dosimeter placed on a patient's skin has potential to serve as an experimental method to monitor and to estimate patient exposure resulting from a kilovoltage x-ray imaging procedure. Due to its large variation in energy response, nanoDot is not suitable to measure radiation doses resulting from mixed beams of megavoltage therapeutic and kilovoltage imaging radiations.

Ding, George X.; Malcolm, Arnold W.

2013-09-01

231

Adaptive optics fundus images of cone photoreceptors in the macula of patients with retinitis pigmentosa  

PubMed Central

Background The purpose of this study was to examine cone photoreceptors in the macula of patients with retinitis pigmentosa using an adaptive optics fundus camera and to investigate any correlations between cone photoreceptor density and findings on optical coherence tomography and fundus autofluorescence. Methods We examined two patients with typical retinitis pigmentosa who underwent ophthalmological examination, including measurement of visual acuity, and gathering of electroretinographic, optical coherence tomographic, fundus autofluorescent, and adaptive optics fundus images. The cone photoreceptors in the adaptive optics images of the two patients with retinitis pigmentosa and five healthy subjects were analyzed. Results An abnormal parafoveal ring of high-density fundus autofluorescence was observed in the macula in both patients. The border of the ring corresponded to the border of the external limiting membrane and the inner segment and outer segment line in the optical coherence tomographic images. Cone photoreceptors at the abnormal parafoveal ring were blurred and decreased in the adaptive optics images. The blurred area corresponded to the abnormal parafoveal ring in the fundus autofluorescence images. Cone densities were low at the blurred areas and at the nasal and temporal retina along a line from the fovea compared with those of healthy controls. The results for cone spacing and Voronoi domains in the macula corresponded with those for the cone densities. Conclusion Cone densities were heavily decreased in the macula, especially at the parafoveal ring on high-density fundus autofluorescence in both patients with retinitis pigmentosa. Adaptive optics images enabled us to observe in vivo changes in the cone photoreceptors of patients with retinitis pigmentosa, which corresponded to changes in the optical coherence tomographic and fundus autofluorescence images.

Tojo, Naoki; Nakamura, Tomoko; Fuchizawa, Chiharu; Oiwake, Toshihiko; Hayashi, Atsushi

2013-01-01

232

Reliable and robust transmission and storage techniques for medical images with patient information.  

PubMed

There is an increased emphasis on the use of digital techniques in all aspects of human life today. Broadcast radio and television, cellular phone services, consumer and entertainment electronics etc are increasingly using digital signal processing techniques to improve the quality of service. Transmission and storage of documentation and images pertaining to patient records cannot remain an exception to this global trend. Hence, patient records (text and image information) are increasingly stored and processed in digital form. Currently, text and image information, which constitute two separate pieces of data are handled as different files. Thus, there is a possibility of the text and message information, pertaining to different patients, being interchanged and thus mishandled. This can be avoided by merging text and image information in such a manner that the two can be separated without perceptible damage to information contained in either file. Digital watermarking techniques can be used to interleave patient information with medical images. In this work, we have employed digital watermarking along with strong cryptographic protocols and powerful error correcting codes. This reduces the probability of sensitive patient information falling into the wrong hands and ensures information integrity when it is conveyed over noisy channels. PMID:20703594

Nergui, Myagmarbayar; Acharya, U Sripati; Acharya U, Rajendra; Yu, Wenwei

2010-12-01

233

Seeing, mirroring, desiring: the impact of the analyst's pregnant body on the patient's body image.  

PubMed

The paper explores the impact of the analyst's pregnant body on the course of two analyses, a young man, and a young woman, specifically focusing on how each patient's visual perception and affective experience of being with the analyst's pregnant body affected their own body image and subjective experience of their body. The pre-verbal or 'subsymbolic' material evoked in the analyses contributed to a greater understanding of the patients' developmental experiences in infancy and adolescence, which had resulted in both carrying a profoundly distorted body image into adulthood. The analyst's pregnancy offered a therapeutic window in which a shift in the patient's body image could be initiated. Clinical material is presented in detail with reference to the psychoanalytic literature on the pregnant analyst, and that of the development of the body image, particularly focusing on the role of visual communication and the face. The author proposes a theory of psychic change, drawing on Bucci's multiple code theory, in which the patients' unconscious or 'subsymbolic' awareness of her pregnancy, which were manifest in their bodily responses, feeling states and dreams, as well as in the analyst s countertransference, could gradually be verbalized and understood within the transference. Thus visual perception, or 'external seeing', could gradually become 'internal seeing', or insight into unconscious phantasies, leading to a shift in the patients internal object world towards a less persecutory state and more realistic appraisal of their body image. PMID:23924329

Yakeley, Jessica

2013-08-01

234

Th22 Cells as Well as Th17 Cells Expand Differentially in Patients with Early-Stage and Late-Stage Myelodysplastic Syndrome  

PubMed Central

Background Immunological mechanisms are increasingly recognized in the progression of myelodysplastic syndrome (MDS). Early-stage MDS (E-MDS) is characterized by autoimmune-mediated myelosuppression whereas late-stage MDS (L-MDS) involves immune evasion, giving dysplastic cells growth potential to progress into acute myeloid leukemia. T-helper (Th) 22 is involved in the pathogenesis of inflammatory autoimmunity and tumorigenesis. The roles of Th22 cells in the pathophysiology of E-MDS and L-MDS remain unsettled. Design and Methods We studied 37 MDS patients (E-MDS, n?=?17; L-MDS, n?=?20) and 20 healthy controls to characterize their peripheral blood (PB), as well as 25 MDS patients and 10 healthy controls to characterize their bone marrow(BM). The expression of Interleukin-22 (IL-22), IL-17 or interferon gamma (IFN-?) was examined in E-MDS, L-MDS patients and controls by flow cytometry. The mRNA expression levels of RAR-related orphan receptor C (RORC), IL-6, tumor necrosis factor alpha (TNF-?) and IL-23 in peripheral blood mononuclear cells (PBMCs) were determined by real-time quantitative polymerase chain reaction. The levels of IL-22 and IL-17 both in PB and BM plasma were examined by enzyme-linked immunosorbent assay. Results In E-MDS, peripheral Th17 cells were significantly elevated and correlated with peripheral Th22 cells compared with healthy controls and L-MDS. Significantly higher levels of peripheral Th22 expansion, mRNA expression of IL-6, TNF-? and lower level of RORC mRNA expression were observed in L-MDS compared with E-MDS. No statistical difference was found in IL-23 mRNA expression or plasma IL-22, IL-17 levels among E-MDS, L-MDS and controls. Conclusions Our data demonstrated that L-MDS cohort had increased frequencies of peripheral Th22 cells and higher mRNA expression levels of IL-6 and TNF-?, indicating that Th22 cells along with Th17 cells or not are involved in the dynamic immune responses of MDS.

Shao, Lin-lin; Zhang, Lei; Hou, Yu; Yu, Shuang; Liu, Xin-guang; Huang, Xiao-yang; Sun, Yuan-xin; Tian, Tian; He, Na; Ma, Dao-xin; Peng, Jun; Hou, Ming

2012-01-01

235

Electroencephalographic source imaging: a prospective study of 152 operated epileptic patients  

PubMed Central

Electroencephalography is mandatory to determine the epilepsy syndrome. However, for the precise localization of the irritative zone in patients with focal epilepsy, costly and sometimes cumbersome imaging techniques are used. Recent small studies using electric source imaging suggest that electroencephalography itself could be used to localize the focus. However, a large prospective validation study is missing. This study presents a cohort of 152 operated patients where electric source imaging was applied as part of the pre-surgical work-up allowing a comparison with the results from other methods. Patients (n = 152) with >1 year postoperative follow-up were studied prospectively. The sensitivity and specificity of each imaging method was defined by comparing the localization of the source maximum with the resected zone and surgical outcome. Electric source imaging had a sensitivity of 84% and a specificity of 88% if the electroencephalogram was recorded with a large number of electrodes (128–256 channels) and the individual magnetic resonance image was used as head model. These values compared favourably with those of structural magnetic resonance imaging (76% sensitivity, 53% specificity), positron emission tomography (69% sensitivity, 44% specificity) and ictal/interictal single-photon emission-computed tomography (58% sensitivity, 47% specificity). The sensitivity and specificity of electric source imaging decreased to 57% and 59%, respectively, with low number of electrodes (<32 channels) and a template head model. This study demonstrated the validity and clinical utility of electric source imaging in a large prospective study. Given the low cost and high flexibility of electroencephalographic systems even with high channel counts, we conclude that electric source imaging is a highly valuable tool in pre-surgical epilepsy evaluation.

Brodbeck, Verena; Spinelli, Laurent; Lascano, Agustina M.; Wissmeier, Michael; Vargas, Maria-Isabel; Vulliemoz, Serge; Pollo, Claudio; Schaller, Karl; Michel, Christoph M.

2011-01-01

236

Mechanically expandable annular seal  

DOEpatents

A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.

Gilmore, R.F.

1983-07-19

237

Mechanically expandable annular seal  

DOEpatents

A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluidtight barrier. A counterrotation removes the barrier.

Gilmore, Richard F. (Kennewick, WA)

1983-01-01

238

Expanding hollow metal rings  

DOEpatents

A sealing device that may expand more planar dimensions due to internal thermal expansion of a filler material. The sealing material is of a composition such that when desired environment temperatures and internal actuating pressures are reached, the sealing materials undergoes a permanent deformation. For metallic compounds, this permanent deformation occurs when the material enters the plastic deformation phase. Polymers, and other materials, may be using a sealing mechanism depending on the temperatures and corrosivity of the use. Internal pressures are generated by either rapid thermal expansion or material phase change and may include either liquid or solid to gas phase change, or in the gaseous state with significant pressure generation in accordance with the gas laws. Sealing material thickness and material composition may be used to selectively control geometric expansion of the seal such that expansion is limited to a specific facing and or geometric plane.

Peacock, Harold B. (Evans, GA) [Evans, GA; Imrich, Kenneth J. (Grovetown, GA) [Grovetown, GA

2009-03-17

239

Model-based estimation of breast percent density in raw and processed full-field digital mammography images from image-acquisition physics and patient-image characteristics  

NASA Astrophysics Data System (ADS)

Breast percent density (PD%), as measured mammographically, is one of the strongest known risk factors for breast cancer. While the majority of studies to date have focused on PD% assessment from digitized film mammograms, digital mammography (DM) is becoming increasingly common, and allows for direct PD% assessment at the time of imaging. This work investigates the accuracy of a generalized linear model-based (GLM) estimation of PD% from raw and postprocessed digital mammograms, utilizing image acquisition physics, patient characteristics and gray-level intensity features of the specific image. The model is trained in a leave-one-woman-out fashion on a series of 81 cases for which bilateral, mediolateral-oblique DM images were available in both raw and post-processed format. Baseline continuous and categorical density estimates were provided by a trained breast-imaging radiologist. Regression analysis is performed and Pearson's correlation, r, and Cohen's kappa, ?, are computed. The GLM PD% estimation model performed well on both processed (r=0.89, p<0.001) and raw (r=0.75, p<0.001) images. Model agreement with radiologist assigned density categories was also high for processed (?=0.79, p<0.001) and raw (?=0.76, p<0.001) images. Model-based prediction of breast PD% could allow for a reproducible estimation of breast density, providing a rapid risk assessment tool for clinical practice.

Keller, Brad M.; Nathan, Diane L.; Conant, Emily F.; Kontos, Despina

2012-02-01

240

Image enhancement of high digital magnification for patients with central vision loss  

NASA Astrophysics Data System (ADS)

We have developed a mobile vision assistive device based on a head mounted display (HMD) with a video camera, which provides image magnification and contrast enhancement for patients with central field loss (CFL). Because the exposure level of the video camera is usually adjusted according to the overall luminance of the scene, the contrast of sub-images (to be magnified) may be low. We found that at high magnification levels, conventional histogram enhancement methods frequently result in over- or under-enhancement due to irregular histogram distribution of subimages. Furthermore, the histogram range of the sub-images may change dramatically when the camera moves, which may cause flickering. A piece-wise histogram stretching method based on a center emphasized histogram is proposed and evaluated by observers. The center emphasized histogram minimizes the histogram fluctuation due to image changes near the image boundary when the camera moves slightly, which therefore reduces flickering after enhancement. A piece-wise histogram stretching function is implemented by including a gain turnaround point to deal with very low contrast images and reduce the possibility of over enhancement. Six normally sighted subjects and a CFL patient were tested for their preference of images enhanced by the conventional and proposed methods as well as the original images. All subjects preferred the proposed enhancement method over the conventional method.

Li, Zhengzhou; Luo, Gang; Peli, Eli

2011-02-01

241

Multimodality Imaging in an Adult Patient with Scimitar Syndrome  

PubMed Central

The “Scimitar syndrome” is a rare congenital anomaly characterized by combination of partial or complete pulmonary venous return from the right lung to the inferior vena cava either above or below the diaphragm together with hypoplasia of the right lung and sometimes systemic arterial supply to the right lung. In this case, multimodality imaging findings such as the vein draining into the inferior vena cava, the presence of hypertrophied and dilated right ventricle, the absence of other cardiac abnormalities, displacement of the heart without malrotation and the mediastinum to the right, normal bronchial and vascular continuity in the whole lung, absence of pulmonary sequestration and systemic collaterals, normal perfusion and systolic functions of the left ventricle were reported.

Karacal?oglu, Alper Ozgur; Gumus, Seyfettin; Ince, Semra; Demirkol, Sait

2014-01-01

242

Whole-brain arterial spin labeling perfusion MR imaging in patients with acute stroke  

PubMed Central

Background and purpose Perfusion MRI can be used to identify patients with acute ischemic stroke that may benefit from reperfusion therapies. The risk of nephrogenic systemic fibrosis, however, limits the use of contrast agents. Our objective was to evaluate the ability of arterial spin labeling (ASL), an alternative non-invasive perfusion technique, to detect perfusion deficits compared with dynamic susceptibility contrast (DSC) perfusion imaging. Methods Consecutive patients referred for emergency assessment of suspected acute stroke within a seven-month period were imaged with both ASL and DSC perfusion MRI. Images were interpreted in a random order by two experts blinded to clinical information for image quality, presence of perfusion deficits and diffusion-perfusion mismatches. Results 156 patients were scanned with a median time of 5.6 (3.0–17.7) hours from last seen normal. Stroke diagnosis was clinically confirmed in 78 patients. ASL and DSC imaging were available in 64 of these patients. A perfusion deficit was detected with DSC in 39 of these patients; ASL detected 32 of these index perfusion deficits, missing 7 lesions. The median volume of the perfusion deficits as determined with DSC was smaller in patients which were evaluated as normal with ASL than in those with a deficit (median, interquartile range; 56 (10–116) vs. 114 (41–225) ml, p=0.01). Conclusions ASL can depict large perfusion deficits and perfusion/diffusion mismatches in correspondence with DSC. Our findings show that a fast 2½ minute ASL perfusion scan may be adequate for screening acute stroke patients with contraindications to gadolinium-based contrast agents.

Bokkers, Reinoud P.H.; Hernandez, Daymara A.; Merino, Jose G.; Mirasol, Raymond V.; van Osch, M.J.; Hendrikse, Jeroen; Warach, Steven; Latour, Lawrence L.

2012-01-01

243

Integration of patient specific modeling and advanced image processing techniques for image-guided neurosurgery  

Microsoft Academic Search

A major challenge in neurosurgery oncology is to achieve maximal tumor removal while avoiding postoperative neurological deficits. Therefore, estimation of the brain deformation during the image guided tumor resection process is necessary. While anatomic MRI is highly sensitive for intracranial pathology, its specificity is limited. Different pathologies may have a very similar appearance on anatomic MRI. Moreover, since fMRI and

Neculai Archip; Andriy Fedorov; Bryn Lloyd; Nikos Chrisochoides; Alexandra Golby; Peter M. Black; Simon K. Warfield

2006-01-01

244

Development of Fast and Highly Efficient Gas Ionization Chamber For Patient Imaging and Dosimetry in Radiation Therapy  

SciTech Connect

In radiation therapy of cancer, more accurate delivery techniques spur the need for improved patient imaging during treatment. To this purpose, the megavoltage radiation protocol that is used for treatment is also used for imaging.

R. Hinderler; H. Keller; T.R. Mackie; M.L. Corradini

2003-09-08

245

Influence of exposure parameters on patient dose and image noise in computed tomography  

NASA Astrophysics Data System (ADS)

This work presents the results of investigation of influence of main exposure parameters on the patient dose and image noise on five clinical computed tomography units. Patient dose was determined by means of the quantity CTDIair free on air measured with pencil shaped ionization chamber. The image noise was estimated as a standard deviation of CT numbers in a 500 mm2 central region of interest in a water-equivalent phantom positioned in the centre of rotation. The alteration of tube voltage and tube current show the potential in patient dose reduction up to 40% but may deteriorate image quality and has to be carefully applied in order to optimize the clinical CT protocols taking into account the specific clinical task. This survey is essential for optimization of routine CT protocols especially for CT units without automatic exposure control systems, which are main part of CT units in Bulgaria.

Stoyanov, Desislav; Vassileva, Jenia

2009-01-01

246

Deformable image registration for geometrical evaluation of DIBH radiotherapy treatment of lung cancer patients  

NASA Astrophysics Data System (ADS)

Respiration and anatomical variation during radiotherapy (RT) of lung cancer yield dosimetric uncertainties of the delivered dose, possibly affecting the clinical outcome if not corrected for. Adaptive radiotherapy (ART), based on deformable image registration (DIR) and Deep-Inspiration-Breath-Hold (DIBH) gating can potentially improve the accuracy of RT. Purpose: The objective was to investigate the performance of contour propagation on repeated CT and Cone Beam CT (CBCT) images in DIBH compared to images acquired in free breathing (FB), using a recently released DIR software. Method: Three locally advanced non-small cell lung cancer patients were included, each with a planning-, midterm- and final CT (pCT, mCT, fCT) and 7 CBCTs acquired weekly and on the same day as the mCT and fCT. All imaging were performed in both FB and DIBH, using Varian RPM system for respiratory tracking. Delineations of anatomical structures were performed on each image set. The CT images were retrospective rigidly and deformable registered to all obtained images using the Varian Smart Adapt v. 11.0. The registered images were analysed for volume change and Dice Similarity Coefficient (DSC). Result: Geometrical similarities were found between propagated and manually delineated structures, with a slightly favour of FB imaging. Special notice should be taken to registrations where image artefacts or low tissue contrast are present. Conclusion: This study does not support the hypothesis that DIBH images perform better image registration than FB images. However DIR is a feasible tool for ART of lung cancer.

Ottosson, W.; Lykkegaard Andersen, J. A.; Borrisova, S.; Mellemgaard, A.; Behrens, C. F.

2014-03-01

247

Patient dose considerations for routine megavoltage cone-beam CT imaging  

Microsoft Academic Search

Megavoltage cone-beam CT (MVCBCT), the recent addition to the family of in-room CT imaging systems for image-guided radiation therapy (IGRT), uses a conventional treatment unit equipped with a flat panel detector to obtain a three-dimensional representation of the patient in treatment position. MVCBCT has been used for more than two years in our clinic for anatomy verification and to improve

Olivier Morin; Amy Gillis; Martina Descovich; Josephine Chen; Michèle Aubin; Jean-François Aubry; Hong Chen; Alexander R. Gottschalk; Ping Xia; Jean Pouliot

2007-01-01

248

Perspectives and limitations of image-guided neurosurgery in pediatric patients  

Microsoft Academic Search

Introduction Progress in image-guided neurosurgery, and specifically in computer-assisted frameless navigation techniques and the application of robotic systems, has brought about many changes in the way we approach and treat pathologies involving the adult and pediatric central nervous system (CNS). Nevertheless, children are a patient group with special demands, in whom image-guided surgical techniques have certain limitations. In this article

Vassilios I. Vougioukas; Ulrich Hubbe; Albrecht Hochmuth; Nils C. Gellrich; Vera van Velthoven

2003-01-01

249

An image-based modeling framework for patient-specific computational hemodynamics  

Microsoft Academic Search

We present a modeling framework designed for patient-specific computational hemodynamics to be performed in the context of\\u000a large-scale studies. The framework takes advantage of the integration of image processing, geometric analysis and mesh generation\\u000a techniques, with an accent on full automation and high-level interaction. Image segmentation is performed using implicit deformable\\u000a models taking advantage of a novel approach for selective

Luca Antiga; Marina Piccinelli; Lorenzo Botti; Bogdan Ene-Iordache; Andrea Remuzzi; David A. Steinman

2008-01-01

250

A multiparametric brain and cord MR imaging study of a patient with Hirayama disease.  

PubMed

In this study, we used a multiparametric MR imaging approach to assess a patient with Hirayama disease (HD). We found that cervical cord damage extends beyond cord T2-visible lesions. We also showed an altered pattern of cortical activations during movements of clinically unaffected limbs. Whereas this study suggests a more widespread cord involvement in HD than seen on routine MR imaging, its cause remains unclear (vascular damage versus a primary lower motor neuron disease). PMID:17110678

Gallo, A; Rocca, M A; Tortorella, P; Ammendola, A; Tedeschi, G; Filippi, M

2006-01-01

251

Contrast-Enhanced MR Imaging of Lymph Nodes in Cancer Patients  

PubMed Central

The accurate identification and characterization of lymph nodes by modern imaging modalities has important therapeutic and prognostic significance for patients with newly diagnosed cancers. The presence of nodal metastases limits the therapeutic options, and it generally indicates a worse prognosis for the patients with nodal metastases. Yet anatomic imaging (CT and MR imaging) is of limited value for depicting small metastatic deposits in normal-sized nodes, and nodal size is a poor criterion when there is no extracapsular extension or focal nodal necrosis to rely on for diagnosing nodal metastases. Thus, there is a need for functional methods that can be reliably used to identify small metastases. Contrast-enhanced MR imaging of lymph nodes is a non-invasive method for the analysis of the lymphatic system after the interstitial or intravenous administration of contrast media. Moreover, some lymphotrophic contrast media have been developed and used for detecting lymph node metastases, and this detection is independent of the nodal size. This article will review the basic principles, the imaging protocols, the interpretation and the accuracies of contrast-enhanced MR imaging of lymph nodes in patients with malignancies, and we also focus on the recent issues cited in the literature. In addition, we discuss the results of several pre-clinical studies and animal studies that were conducted in our institution.

Choi, Seung Hong

2010-01-01

252

Prospective Imaging Biomarker Assessment of Mortality Risk in Patients Treated with Head and Neck Radiotherapy  

PubMed Central

Purpose The optimal roles for imaging-based biomarkers in the management of head and neck cancer remain undefined. Unresolved questions include whether functional or anatomic imaging biomarkers might improve mortality risk assessment for this disease. We addressed these issues in a prospective institutional trial. Methods and Materials Ninety-eight patients with locally advanced pharyngolaryngeal squamous cell cancer were enrolled. Each underwent pre-and post-chemoradiotherapy contrast-enhanced CT and FDG-PET/CT imaging. Imaging parameters were correlated with survival outcomes. Results Low post-radiation primary tumor FDG avidity correlated with improved survival on multivariate analysis; so too did complete primary tumor response by CT alone. Although both imaging modalities lacked sensitivity, each had high specificity and negative predictive value for disease-specific mortality risk assessment. Kaplan-Meier estimates confirmed that both CT and FDG-PET/CT stratify patients into distinct high- and low-probability survivorship groups on the basis of primary tumor response to radiotherapy. Subset analyses demonstrated that the prognostic value for each biomarker was primarily derived from patients at high risk for local treatment failure (HPV-negative disease, non-oropharyngeal primary disease, or tobacco use). Conclusions CT- and FDG-PET/CT-based biomarkers are useful clinical tools in head and neck cancer-specific mortality risk assessment following radiotherapy, particularly for high-risk HPV-unrelated disease. Focus should be placed on further refinement and corroboration of imaging-based biomarkers in future studies.

Moeller, Benjamin J.; Rana, Vishal; Cannon, Blake A.; Williams, Michelle D.; Sturgis, Erich M.; Ginsberg, Lawrence E.; Macapinlac, Homer A.; Lee, J. Jack; Ang, K. Kian; Chao, K.S. Clifford; Chronowski, Gregory M.; Frank, Steven J.; Morrison, William H.; Rosenthal, David I.; Weber, Randal S.; Garden, Adam S.; Lippman, Scott M.; Schwartz, David L.

2010-01-01

253

Radiation Exposure from Abdominal Imaging Studies in Patients with Intestinal Beh?et Disease  

PubMed Central

Background/Aims Recently, several studies have revealed that diagnostic imaging can result in exposure to harmful levels of ionizing radiation in inflammatory bowel disease patients. However, the extent of radiation exposure in intestinal Behcet disease (BD) patients has not been documented. The aim of this study was to estimate the radiation exposure from abdominal imaging studies in intestinal BD patients. Methods Patients with a diagnosis of intestinal BD established between January 1990 and March 2012 were investigated at a single tertiary academic medical center. The cumulative effective dose (CED) was calculated retrospectively from standard tables and by counting the number of abdominal imaging studies performed. High exposure was defined as CED >50 mSv. Results In total, 270 patients were included in the study. The mean CED was 41.3 mSv, and 28.1% of patients were exposed to high levels of radiation. Computed tomography (CT) accounted for 81.7% of the total effective dose. In multivariate analyses, predictors of high radiation exposure were azathioprine/6-mercaptopurine use, surgery, and hospitalization. Conclusions Approximately a quarter of intestinal BD patients were exposed to harmful levels of diagnostic radiation, mainly from CT examination. Clinicians should reduce the number of unnecessary CT examinations and consider low-dose CT profiles or alternative modalities such as magnetic resonance enterography.

Jung, Yoon Suk; Park, Dong Il; Moon, Chang Mo; Park, Soo Jung; Hong, Sung Pil; Kim, Tae Il; Kim, Won Ho; Cheon, Jae Hee

2014-01-01

254

Modulation of brain response to emotional images by alcohol cues in alcohol-dependent patients.  

PubMed

Alcohol is often used to modulate mood states. Alcohol drinkers report that they use alcohol both to enhance positive affect and to reduce dysphoria, and alcohol-dependent patients specifically state reduction of negative affect as a primary reason for drinking. The current study proposes that alcohol cues may reduce negative affect in alcoholics. We used functional magnetic resonance imaging to examine brain activation in response to combination images that juxtaposed negative or positive International Affective Picture System (IAPS) images with an alcohol or non-alcohol-containing beverage. We found that in the absence of the alcohol cue, alcoholics showed more activation to negative than to positive images and greater activation than controls to negative images. When the IAPS images were presented with the alcohol cue, there was a decreased difference in activation between the positive and negative images among the alcoholics, and a decreased difference in response to the negative images between controls and alcoholics. Additionally, in the neutral-beverage conditions, anxiety ratings significantly predicted activation in the right parahippocampal gyrus but did not predict activation when the alcohol cues were presented. In conclusion, the alcohol cues may have modulated cortical networks involved in the processing of emotional stimuli by eliciting a conditioned response in the alcoholics, but not in the controls, which may have decreased responsiveness to the negative images. PMID:18507736

Gilman, Jodi M; Hommer, Daniel W

2008-09-01

255

On the way to a patient table integrated scanner system in magnetic particle imaging  

NASA Astrophysics Data System (ADS)

Magnetic Particle Imaging is capable of three-dimensional real-time imaging. Due to high spatial and temporal resolution, the method offers a great potential to be used in interventional scenarios. In this contribution, a design study integrating a single-sided coil assembly into a patient table is presented. An elliptical and an approximated elliptical coil topology are compared and proposed as alternatives to the commonly used circular shaped coils. Through this, the size of the field of view can be extended while not exceeding the lateral width of the patient table.

Kaethner, C.; Ahlborg, M.; Gräfe, K.; Bringout, G.; Sattel, T. F.; Buzug, T. M.

2014-03-01

256

Kilovoltage Imaging Doses in the Radiotherapy of Pediatric Cancer Patients  

SciTech Connect

Purpose: To investigate doses induced by kilovoltage cone-beam computed tomography (kVCBCT) to pediatric cancer patients undergoing radiotherapy, as well as strategies for dose reduction. Methods and Materials: An EGS4 Monte Carlo code was used to calculate three-dimensional dose deposition due to kVCBCT on 4 pediatric cancer patients. Absorbed doses to various organs were analyzed for both half-fan and full-fan modes. Clinical conditions, such as distance from organ at risk (OAR) to CBCT field border, kV peak energy, and testicular shielding, were studied. Results: The mean doses induced by one CBCT scan operated at 125 kV in half-fan mode to testes, liver, kidneys, femoral heads, spinal cord, brain, eyes, lens, and optical nerves were 2.9, 4.7, 7.7, 10.5, 8.8, 7.6, 7.7, 7.8, and 7.2 cGy, respectively. Increasing the distances from OARs to CBCT field border greatly reduced the doses to OARs, ranging from 33% reduction for spinal cord to 2300% reduction for testes. As photon beam energy increased from 60 to 125 kV, the dose increase due to kVCBCT ranged from 170% for lens to 460% for brain and spinal cord. A testicular shielding made of 1-cm cerrobend could reduce CBCT doses down to 31%, 51%, 68%, and 82%, respectively, for 60, 80, 100, and 125 kV when the testes lay within the CBCT field. Conclusions: Generally speaking, kVCBCT deposits much larger doses to critical structures in children than in adults, usually by a factor of 2 to 3. Increasing the distances from OARs to CBCT field border greatly reduces doses to OARs. Depending on OARs, kVCBCT-induced doses increase linearly or exponentially with photon beam energy. Testicular shielding works more efficiently at lower kV energies. On the basis of our study, it is essential to choose an appropriate scanning protocol when kVCBCT is applied to pediatric cancer patients routinely.

Deng Jun, E-mail: jun.deng@yale.edu [Department of Therapeutic Radiology, Yale University, New Haven, CT (United States); Chen Zhe; Roberts, Kenneth B.; Nath, Ravinder [Department of Therapeutic Radiology, Yale University, New Haven, CT (United States)

2012-04-01

257

Pancreas imaging by computed tomography after endoscopic retrograde pancreatography. [Dogs; patients  

SciTech Connect

A method using CT after endoscopic retrograde pancreatography (CT-ERP) is described for pancreatic imaging. When using an ERP technique in the canine model comparable to that used in humans, small amounts of contrast material in peripheral pancreatic radicles resulted in enhancement of the pancreas on CT scans. Nine patients were also studied by CT-ERP images. The main pancreatic duct was seen on delayed images. In cases of chronic pancreatitis (n = 2), pancreatic opacification was patchy and heterogeneous. There was no contrast-material enhancement in areas of pancreatic carcimomas (n = 2). CT-ERP showed the true extent of carcinoma better than ERP alone.

Frick, M.P.; O'Leary, J.F.; Salomonowitz, E.; Stoltenberg, E.; Hutton, S.; Gedgaudas, E.

1984-01-01

258

Patient dose evaluation by means of DICOM images for a direct radiography system  

Microsoft Academic Search

Purpose  The purpose of this work was to evaluate the statistical distribution of patient dose for different examinations by using\\u000a the data stored in a DICOM image archive of a direct digital radiography system.\\u000a \\u000a \\u000a \\u000a Materials and methods  An automatic procedure to extract dose data and exposure parameters from the image archives was implemented. During a 4.5-month\\u000a period, 8,292 images were collected. Exposure

O. Rampado; E. Garelli; R. Zatteri; U. Escoffier; R. De Lucchi; R. Ropolo

2008-01-01

259

Ultrasound imaging for the rheumatologist. XLII. Assessment of hip pain in rheumatic patients: the radiologist's view.  

PubMed

Hip pain is a common complaint in daily practice and the identification of the underlying pathologic condition is the first step for an adequate treatment. In this review, we discuss the available evidence for the application of conventional radiography, computed tomography and magnetic resonance imaging in rheumatologic patients with painful hip, presenting the main imaging findings due to osteoarthritis, inflammatory arthritis (rheumatoid arthritis and spondyloarthritides), osteonecrosis and some other soft tissue involvement (bursitis and synovial cyst) that could be the cause of hip pain. Because different imaging techniques show different sensitivity and specificity, the choice of technique to use depends on the type and stage of the disease itself. PMID:23253630

Vitali, Saverio; Delle Sedie, Andrea; Filippucci, Emilio; Riente, Lucrezia; Iagnocco, Annamaria; Sakellariou, Garifallia; Meenagh, Gary; Paolicchi, Alessandro; Montecucco, Carlomaurizio; Valesini, Guido; Grassi, Walter; Bombardieri, Stefano; Caramella, Davide

2012-01-01

260

Pattern of brain blood perfusion in tinnitus patients using technetium-99m SPECT imaging  

PubMed Central

Background and Purpose: Tinnitus is associated with an increased activity in central auditory system as demonstrated by neuroimaging studies. Brain perfusion scanning using single photon emission computed tomography (SPECT) was done to understand the pattern of brain blood perfusion of tinnitus subjects and find the areas which are mostly abnormal in these patients. Materials and Methods: A number of 122 patients with tinnitus were enrolled to this cross-sectional study. They underwent SPECT and magnetic resonance imaging (MRI) of brain, and the images were fused to find the regions with abnormal perfusion. Results: SPECT scan results were abnormal in 101 patients (83%). Most patients had bilateral abnormal perfusion (N = 65, 53.3%), and most subjects had abnormality in middle-temporal gyrus (N = 83, 68%) and temporoparietal cortex (N = 46, 37.7%). Patients with multifocal involvement had the least mean age than other 2 groups (patients with no abnormality and unifocal abnormality) (P value = 0.045). Conclusions: Brain blood perfusion pattern differs in patient with tinnitus than others. These patients have brain perfusion abnormality, mostly in auditory gyrus (middle temporal) and associative cortex (temporoparietal cortex). Multifocal abnormalities might be due to more cognitive and emotional brain centers involvement due to tinnitus or more stress and anxiety of tinnitus in the young patients.

Mahmoudian, Saeid; Farhadi, Mohammad; Gholami, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaei, Mohammad; Ghoreyshi, Esmaeel; Ahmadizadeh, Majid; Lenarz, Thomas

2012-01-01

261

Arrival Time Correction for Dynamic Susceptibility Contrast MR Permeability Imaging in Stroke Patients  

PubMed Central

Purpose To determine if applying an arrival time correction (ATC) to dynamic susceptibility contrast (DSC) based permeability imaging will improve its ability to identify contrast leakage in stroke patients for whom the shape of the measured curve may be very different due to hypoperfusion. Materials and Methods A technique described in brain tumor patients was adapted to incorporate a correction for delayed contrast delivery due to perfusion deficits. This technique was applied to the MRIs of 9 stroke patients known to have blood-brain barrier (BBB) disruption on T1 post contrast imaging. Regions of BBB damage were compared with normal tissue from the contralateral hemisphere. Receiver operating characteristic (ROC) analysis was performed to compare the detection of BBB damage before and after ATC. Results ATC improved the area under the curve (AUC) of the ROC from 0.53 to 0.70. The sensitivity improved from 0.51 to 0.67 and the specificity improved from 0.57 to 0.66. Visual inspection of the ROC curve revealed that the performance of the uncorrected analysis was worse than random guess at some thresholds. Conclusions The ability of DSC permeability imaging to identify contrast enhancing tissue in stroke patients improved considerably when an ATC was applied. Using DSC permeability imaging in stroke patients without an ATC may lead to false identification of BBB disruption.

Leigh, Richard; Jen, Shyian S.; Varma, Daniel D.; Hillis, Argye E.; Barker, Peter B.

2012-01-01

262

Texture analysis of computed tomography images of acute ischemic stroke patients.  

PubMed

Computed tomography (CT) images are routinely used to assess ischemic brain stroke in the acute phase. They can provide important clues about whether to treat the patient by thrombolysis with tissue plasminogen activator. However, in the acute phase, the lesions may be difficult to detect in the images using standard visual analysis. The objective of the present study was to determine if texture analysis techniques applied to CT images of stroke patients could differentiate between normal tissue and affected areas that usually go unperceived under visual analysis. We performed a pilot study in which texture analysis, based on the gray level co-occurrence matrix, was applied to the CT brain images of 5 patients and of 5 control subjects and the results were compared by discriminant analysis. Thirteen regions of interest, regarding areas that may be potentially affected by ischemic stroke, were selected for calculation of texture parameters. All regions of interest for all subjects were classified as lesional or non-lesional tissue by an expert neuroradiologist. Visual assessment of the discriminant analysis graphs showed differences in the values of texture parameters between patients and controls, and also between texture parameters for lesional and non-lesional tissue of the patients. This suggests that texture analysis can indeed be a useful tool to help neurologists in the early assessment of ischemic stroke and quantification of the extent of the affected areas. PMID:19820884

Oliveira, M S; Fernandes, P T; Avelar, W M; Santos, S L M; Castellano, G; Li, L M

2009-11-01

263

Optimization of diagnostic imaging use in patients with acute abdominal pain (OPTIMA): Design and rationale  

PubMed Central

Background The acute abdomen is a frequent entity at the Emergency Department (ED), which usually needs rapid and accurate diagnostic work-up. Diagnostic work-up with imaging can consist of plain X-ray, ultrasonography (US), computed tomography (CT) and even diagnostic laparoscopy. However, no evidence-based guidelines exist in current literature. The actual diagnostic work-up of a patient with acute abdominal pain presenting to the ED varies greatly between hospitals and physicians. The OPTIMA study was designed to provide the evidence base for constructing an optimal diagnostic imaging guideline for patients with acute abdominal pain at the ED. Methods/design Thousand consecutive patients with abdominal pain > 2 hours and < 5 days will be enrolled in this multicentre trial. After clinical history, physical and laboratory examination all patients will undergo a diagnostic imaging protocol, consisting of plain X-ray (upright chest and supine abdomen), US and CT. The reference standard will be a post hoc assignment of the final diagnosis by an expert panel. The focus of the analysis will be on the added value of the imaging modalities over history and clinical examination, relative to the incremental costs. Discussion This study aims to provide the evidence base for the development of a diagnostic algorithm that can act as a guideline for ED physicians to evaluate patients with acute abdominal pain.

Lameris, Wytze; van Randen, Adrienne; Dijkgraaf, Marcel GW; Bossuyt, Patrick MM; Stoker, Jaap; Boermeester, Marja A

2007-01-01

264

Longitudinal changes in patients with traumatic brain injury assessed with diffusion tensor and volumetric imaging  

PubMed Central

Traumatic brain injury (TBI) is associated with brain volume loss, but there is little information on the regional gray matter (GM) and white matter (WM) changes that contribute to overall loss. Since axonal injury is a common occurrence in TBI, imaging methods that are sensitive to WM damage such as diffusion-tensor imaging (DTI) may be useful for characterizing microstructural brain injury contributing to regional WM loss in TBI. High-resolution T1-weighted imaging and DTI were used to evaluate regional changes in TBI patients compared to matched controls. Patients received neuropsychological testing and were imaged approximately 2 months and 12.7 months post injury. Paradoxically, neuropsychological function improved from Visit 1 to Visit 2, while voxel-based analyses of fractional anisotropy (FA), and mean diffusivity (MD) from the DTI images, and voxel-based analyses of the GM and WM probability maps from the T1-weighted images, mainly revealed significantly greater deleterious GM and WM change over time in patients compared to controls. Cross-sectional comparisons of the DTI measures indicated that patients have decreased FA and increased MD compared to controls over large regions of the brain. TBI affected virtually all of the major fiber bundles in the brain including the corpus callosum, cingulum, the superior and inferior longitudinal fascicules, the uncinate fasciculus, and brain stem fiber tracts. The results indicate that both GM and WM degeneration are significant contributors to brain volume loss in the months following brain injury, and also suggest that DTI measures may be more useful than high-resolution anatomical images in assessment of group differences.

Bendlin, Barbara; Ries, Michele L.; Lazar, Mariana; Alexander, Andrew L.; Dempsey, Robert J.; Rowley, Howard A.; Sherman, Jack E.; Johnson, Sterling C.

2008-01-01

265

Accurate positioning for head and neck cancer patients using 2D and 3D image guidance  

PubMed Central

Our goal is to determine an optimized image-guided setup by comparing setup errors determined by two-dimensional (2D) and three-dimensional (3D) image guidance for head and neck cancer (HNC) patients immobilized by customized thermoplastic masks. Nine patients received weekly imaging sessions, for a total of 54, throughout treatment. Patients were first set up by matching lasers to surface marks (initial) and then translationally corrected using manual registration of orthogonal kilovoltage (kV) radiographs with DRRs (2D-2D) on bony anatomy. A kV cone beam CT (kVCBCT) was acquired and manually registered to the simulation CT using only translations (3D-3D) on the same bony anatomy to determine further translational corrections. After treatment, a second set of kVCBCT was acquired to assess intrafractional motion. Averaged over all sessions, 2D-2D registration led to translational corrections from initial setup of 3.5 ± 2.2 (range 0–8) mm. The addition of 3D-3D registration resulted in only small incremental adjustment (0.8 ± 1.5 mm). We retrospectively calculated patient setup rotation errors using an automatic rigid-body algorithm with 6 degrees of freedom (DoF) on regions of interest (ROI) of in-field bony anatomy (mainly the C2 vertebral body). Small rotations were determined for most of the imaging sessions; however, occasionally rotations > 3° were observed. The calculated intrafractional motion with automatic registration was < 3.5 mm for eight patients, and < 2° for all patients. We conclude that daily manual 2D-2D registration on radiographs reduces positioning errors for mask-immobilized HNC patients in most cases, and is easily implemented. 3D-3D registration adds little improvement over 2D-2D registration without correcting rotational errors. We also conclude that thermoplastic masks are effective for patient immobilization.

Kang, Hyejoo; Lovelock, Dale M.; Yorke, Ellen D.; Kriminiski, Sergey; Lee, Nancy; Amols, Howard I.

2011-01-01

266

Pulsed Doppler tissue imaging can help to identify patients with right ventricular infarction  

Microsoft Academic Search

This study was planned to assess whether tissue Doppler imaging is a useful method for the detection of the right ventricular myocardial infarction. Forty-eight patients with acute inferior myocardial infarction and 24 age- and sex-matched healthy controls were included in this study. Twenty-four patients had electrocardiographic signs of inferior myocardial infarction without right ventricular infarction (group I), and the other

Mustafa Yilmaz; Mustafa Kemal Erol; Mahmut Acikel; Serdar Sevimli; Necip Alp

2003-01-01

267

Magnetic resonance imaging of the inner ear in patients with idiopathic sudden sensorineural hearing loss  

Microsoft Academic Search

Although gadolinium-enhanced magnetic resonance imaging (Gd-MRI) has been used to indicate the presence of a subclinical\\u000a labyrinthitis in patients with idiopathic sudden sensorineural hearing loss (ISSHL), its sensitivity in daily clinical practice\\u000a is unknown. We describe Gd-MRI findings in 27 ISSHL patients taking part in a prospective multicenter clinical trial. MRI\\u000a findings were related to the severity of the hearing

R. J. Stokroos; F. W. J. Albers; A. P. Krikke; J. W. Casselman

1998-01-01

268

Doctors, Patients, and Perceived Job Image: An Empirical Study of Stress and Nurses in Singapore  

Microsoft Academic Search

This study examined the relationships among three potential sources of stress, namely, demands from patients\\/relatives, demands from doctors, and perceived job image, and several work-related outcomes, namely, job satisfaction, organizational commitment, intention to quit, and job-induced tension. Respondents consist of nurses from two tertiary-care hospitals in Singapore. Findings of this study suggest that demands from patients\\/relatives, doctors, and perceived job

Vivien K. G. Lim; Edith C. Yuen

1998-01-01

269

Prognostic value of iodine-123 labelled BMIPP fatty acid analogue imaging in patients with myocardial infarction  

Microsoft Academic Search

This study was undertaken to evaluate the prognostic value of iodine-123 labelled 15-iodophenyl3-R,S-methyl pentadecanoic acid (BMIPP) imaging in patients with myocardial infarction. BMIPP is an iodinated methyl branched fatty acid analogue which is trapped in the myocardium with little washout, thereby reflecting fatty acid utilization in the myocardium. We previously reported that in patients with myocardial infarction, regions are often

Nagara Tamaki; Eiji Tadamura; Takashi Kudoh; Naoya Hattori; Yoshiharu Yonekura; Ryuji Nohara; Shigetake Sasayama; Katsuji Ikekubo; Hiroshi Kato; Junji Konishi

1996-01-01

270

Clinical utility of image-guided chest wall mass biopsy: results in 28 patients.  

PubMed

The purpose of our study was to determine the clinical usefulness of percutaneous image-guided biopsy of chest wall masses. A retrospective study of 28 patients who underwent image-guided biopsy of chest wall masses from 2005 to 2007 was performed. In 19 (68%) patients, the mass was detected as part of a staging evaluation in patients with known malignancy; 9 (32%) patients had no known malignancy. Biopsy results were classified as diagnostic (malignant or benign) or non-diagnostic (atypical and insufficient). Sensitivity, specificity and negative predictive value were calculated for all patients, and the Fisher-Freeman-Halton exact test was used to determine if test characteristics varied in patients with and without a history of cancer, masses smaller and greater than 5 cm, or according to needle size. The overall diagnostic rate was 71%. Of these, there were 20 true-positives, 3 true-negatives, 5 false-negatives and no false-positive results (sensitivity 80% (20/25), specificity 100% (3/3) and negative predictive value 37.5% (3/8)). There were no differences between patients with and without cancer. Among 19 patients with known cancer, 10 had metastatic disease from their known primary. Biopsy test characteristics did not differ with respect to mass or needle size. Minor complications were seen in 7% of patients. Image-guided chest wall mass biopsy is a sensitive and specific procedure, which is clinically important in the care of patients both with and without a known primary cancer. PMID:21555261

Souza, Frederico Ferreira; De Angelo Andrade, Maurício; Smith, Andrew; Dei Santi, Daniel B

2011-01-01

271

Chemoembolization for Hepatocellular Carcinoma: Comprehensive Imaging and Survival Analysis in a 172-Patient Cohort 1  

PubMed Central

Purpose: To determine comprehensive imaging and long-term survival outcome following chemoembolization for hepatocellular carcinoma (HCC). Materials and Methods: One hundred seventy-two patients with HCC treated with chemoembolization were studied retrospectively in an institutional review board approved protocol; this study was HIPAA compliant. Baseline laboratory and imaging characteristics were obtained. Clinical and laboratory toxicities following treatment were assessed. Imaging characteristics following chemoembolization were evaluated to determine response rates (size and necrosis) and time to progression (TTP). Survival from the time of first chemoembolization treatment was calculated. Subanalyses were performed by stratifying the population according to Child-Pugh, United Network for Organ Sharing, and Barcelona Clinic for Liver Cancer (BCLC) staging systems. Results: Cirrhosis was present in 157 patients (91%); portal hypertension was present in 139 patients (81%). Eleven patients (6%) had metastases at baseline. Portal vein thrombosis was present in 11 patients (6%). Fifty-five percent of patients experienced some form of toxicity following treatment; 21% developed grade 3 or 4 bilirubin toxicity. Post-chemoembolization response was seen in 31% and 64% of patients according to size and necrosis criteria, respectively. Median TTP was 7.9 months (95% confidence interval: 7.1, 9.4) but varied widely by stage. Median survival was significantly different between patients with BCLC stages A, B, and C disease (stage A, 40.0 months; B, 17.4 months; C, 6.3 months; P < .0001). Conclusion: The determination of TTP and survival in patients with HCC is confounded by tumor biology and background cirrhosis; chemoembolization was shown to be a safe and effective therapy in patients with HCC. © RSNA, 2010

Lewandowski, Robert J.; Mulcahy, Mary F.; Kulik, Laura M.; Riaz, Ahsun; Ryu, Robert K.; Baker, Talia B.; Ibrahim, Saad M.; Abecassis, Michael I.; Miller, Frank H.; Sato, Kent T.; Senthilnathan, Seanthan; Resnick, Scott A.; Wang, Edward; Gupta, Ramona; Chen, Richard; Newman, Steven B.; Chrisman, Howard B.; Nemcek, Albert A.; Vogelzang, Robert L.; Omary, Reed A.; Benson, Al B.

2010-01-01

272

Patient-reported complications from fiducial marker implantation for prostate image-guided radiotherapy  

PubMed Central

Objectives To report on complications from transrectal ultrasound-guided insertion of fiducial markers for prostate image-guided radiotherapy. Methods 234 patients who underwent transrectal fiducial marker insertion for prostate cancer image-guided radiotherapy were assessed retrospectively by questionnaire with regard to the duration and severity of eight symptoms experienced following the procedure. Pain during the implantation procedure was assessed according to the Wong–Baker faces pain scale. Results Of 234 patients, 32% had at least one new symptom after the procedure. The commonest new symptom following the procedure was urinary frequency affecting 16% of patients who had not been troubled by frequency beforehand. Haematuria, rectal bleeding, dysuria and haematospermia affected 9–13% of patients, mostly at Grade 1 or 2. Pain, obstruction, and fever and shivers affected 3–4% of patients. Grade 3 rectal bleeding, haematuria, fever and shivers, and urinary frequency affected 0.5–1.5% of patients. Only one patient had a Grade 4 complication (i.e. fever and shivers). Overall, 9% of patients had symptoms lasting more than 2 weeks. The commonest symptoms that lasted more than 2 weeks were frequency, dysuria, obstructive symptoms and rectal bleeding. Mean pain score during the procedure was 1.1 (range 0–5). Conclusion Transrectal ultrasound-guided fiducial marker insertion for image-guided radiotherapy is well tolerated in the majority of prostate cancer patients. Most symptoms were Grade 1 or 2 in severity. Symptoms in the majority of patients last under 2 weeks. The most serious complication was sepsis in our study.

Gill, S; Li, J; Thomas, J; Bressel, M; Thursky, K; Styles, C; Tai, K H; Duchesne, G M; Foroudi, F

2012-01-01

273

Imaging of the optic disk in caring for patients with glaucoma: Ophthalmoscopy and photography remain the gold standard.  

PubMed

Optic disk imaging is integral to the diagnosis and treatment of patients with glaucoma. We discuss the various forms of imaging the optic nerve, including ophthalmoscopy, photography, and newer imaging modalities, including optical coherence tomography (OCT), confocal scanning laser ophthalmoscopy (HRT), and scanning laser polarimetry (GDx), specifically highlighting their benefits and disadvantages. We argue that ophthalmoscopy and photography remain the gold standard of imaging due to portability, ease of interpretation, and the presence of a large database of images for comparison. PMID:24856360

Spaeth, George L; Reddy, Swathi C

2014-01-01

274

Patient dose considerations for routine megavoltage cone-beam CT imaging  

SciTech Connect

Megavoltage cone-beam CT (MVCBCT), the recent addition to the family of in-room CT imaging systems for image-guided radiation therapy (IGRT), uses a conventional treatment unit equipped with a flat panel detector to obtain a three-dimensional representation of the patient in treatment position. MVCBCT has been used for more than two years in our clinic for anatomy verification and to improve patient alignment prior to dose delivery. The objective of this research is to evaluate the image acquisition dose delivered to patients for MVCBCT and to develop a simple method to reduce the additional dose resulting from routine MVCBCT imaging. Conventional CT scans of phantoms and patients were imported into a commercial treatment planning system (TPS: Phillips, Pinnacle) and an arc treatment mimicking the MVCBCT acquisition process was generated to compute the delivered acquisition dose. To validate the dose obtained from the TPS, a simple water-equivalent cylindrical phantom with spaces for MOSFETs and an ion chamber was used to measure the MVCBCT image acquisition dose. Absolute dose distributions were obtained by simulating MVCBCTs of 9 and 5 monitor units (MU) on pelvis and head and neck patients, respectively. A compensation factor was introduced to generate composite plans of treatment and MVCBCT imaging dose. The article provides a simple equation to compute the compensation factor. The developed imaging compensation method was tested on routinely used clinical plans for prostate and head and neck patients. The quantitative comparison between the calculated dose by the TPS and measurement points on the cylindrical phantom were all within 3%. The dose percentage difference for the ion chamber placed in the center of the phantom was only 0.2%. For a typical MVCBCT, the dose delivered to patients forms a small anterior-posterior gradient ranging from 0.6 to 1.2 cGy per MVCBCT MU. MVCBCT acquisitions in the pelvis and head and neck areas deliver slightly more dose than current portal imaging but render soft tissue information for positioning. Overall, the additional dose from daily 9 MU MVCBCTs of prostate patients is small compared to the treatment dose (<4%). Dose-volume histograms of compensated plans for pelvis and head and neck patients imaged daily with MVCBCT showed no additional dose to the target and small increases at low doses. The results indicate that the dose delivered for MVCBCT imaging can be precisely calculated in the TPS and therefore included in the treatment plan. This allows simple plan compensations, such as slightly reducing the treatment dose, to minimize the total dose received by critical structures from daily positioning with MVCBCT. The proposed compensation factor reduces the number of MU per treatment beam per fraction. Both the number of fractions and the beam arrangement are kept unchanged. Reducing the imaging volume in the cranio-caudal direction can further reduce the dose delivered for MVCBCT. This is a useful feature to eliminate the imaging dose to the eyes or to focus on a specific region of interest for alignment.

Morin, Olivier; Gillis, Amy; Descovich, Martina; Chen, Josephine; Aubin, Michele; Aubry, Jean-Francois; Chen Hong; Gottschalk, Alexander R.; Xia Ping; Pouliot, Jean [Comprehensive Cancer Center, Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143 (United States) and UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158 (United States); Comprehensive Cancer Center, Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143 (United States); Comprehensive Cancer Center, Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143 (United States) and UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, California 94158 (United States)

2007-05-15

275

Implantation of fiducial markers for image guidance in prostate radiotherapy: patient-reported toxicity.  

PubMed

The purpose of this study was to evaluate patient-reported morbidity of implanted fiducial markers used for image guidance in prostate radiotherapy. Three fiducial markers were implanted under transrectal ultrasound guidance to 177 patients who were referred to our department for definitive radiotherapy between June 2005 and January 2008. No local anaesthesia was administered. Patients were asked to complete a questionnaire about the possible side effects of this invasive procedure. 135 patients completed the questionnaire at a median of 57 weeks after the procedure. Pain during the procedure was assessed with the Wong-Baker Faces Pain Rating Scale. Patients were also asked to compare the pain with the diagnostic biopsy. Although haematuria, rectal bleeding and fever were reported by 15%, 4% and 2% of the 135 patients, respectively, no major toxicity necessitating any intervention was observed. The mean pain score reported by the patients was 1.7 (range, 0-5). 87% of patients reported less (or comparable) pain than the diagnostic biopsy. In conclusion, implantation of fiducial markers for image guidance in prostate radiotherapy is a safe and well-tolerated procedure. PMID:19505970

Igdem, S; Akpinar, H; Alço, G; Agaçayak, F; Turkan, S; Okkan, S

2009-11-01

276

Advanced expander test bed program  

NASA Technical Reports Server (NTRS)

The Advanced Expander Test Bed (AETB) is a key element in NASA's Chemical Transfer Propulsion Program for development and demonstration of expander cycle oxygen/hydrogen engine technology component technology for the next space engine. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced missions focused components and new health monitoring techniques. The split-expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

Masters, A. I.; Mitchell, J. C.

1991-01-01

277

Acute necrotizing pancreatitis: laboratory, clinical, and imaging findings as predictors of patient outcome.  

PubMed

OBJECTIVE. In patients with acute necrotizing pancreatitis, we analyzed whether laboratory and clinical findings determined in the early phase of disease and morphologic features on contrast-enhanced CT (CECT) at the beginning of the late phase of disease are helpful in predicting patient outcome and whether CECT findings provide additional information in establishing prognosis compared with the laboratory and clinical findings. MATERIALS AND METHODS. A retrospective analysis of 99 patients with acute necrotizing pancreatitis was performed. Four laboratory variables (albumin, calcium, C-reactive protein, WBC count) and three clinical variables (Acute Physiology, Age, Chronic Health Evaluation [APACHE] II score; Simplified Acute Physiology Score [SAPS] II; persistent organ failure) were assessed. Five morphologic features on CECT including Balthazar grade and CT severity index were reviewed. The endpoints of patient outcome were peripancreatic or pancreatic infection, need for intervention, duration of organ failure, ICU and hospital stays, and death. Based on receiver operating characteristic curve analysis for infection, high-and low-risk groups for each prognostic variable were calculated and univariable and multivariable Cox regression analyses were carried out. RESULTS. In our study population of 99 patients (63 men, 36 women; median age, 52 years; age range, 18-84 years), 25 patients (25%) developed infection, 42 patients (42%) experienced organ failure, and 12 patients (12%) died. Regarding the laboratory and clinical variables, albumin level, APACHE II score, and particularly persistent organ failure were the strongest independent predictors of patient outcome. Regarding the imaging variables, Balthazar grade and a morphologic feature that takes the distribution of intrapancreatic necrosis into account were the strongest independent predictors. In the multivariable analysis of all studied variables, imaging variables were independent and strong predictors of patient outcome and provided additional information in establishing prognosis compared with clinical and laboratory findings. CONCLUSION. In patients with suspected or proven acute necrotizing pancreatitis, performing CECT at the beginning of the late phase of disease is recommended to identify patients at increased risk for adverse outcomes. PMID:24848818

Brand, Michael; Götz, Andrea; Zeman, Florian; Behrens, Gundula; Leitzmann, Michael; Brünnler, Tanja; Hamer, Okka W; Stroszczynski, Christian; Heiss, Peter

2014-06-01

278

Early Registration of Diffusion Tensor Images for Group Tractography of Dystonia Patients  

PubMed Central

Purpose To make a group comparison of diffusion tensor imaging (DTI) results of dystonia patients and controls to reveal occult pathology. We propose using an early registration method that produces sharper group images and enables us to do group tractography. Materials and Methods Twelve dystonia patients manifesting the disease, seven nonmanifesting dystonia mutation carriers (DYT1 and DYT6 gene mutations), and eight age-matched normal control subjects were imaged for a previous study. Early and late registration methods for DTI were compared. An early registration technique for a super set was proposed, in which the diffusion-weighted images were registered to a template, gradient vectors were reoriented for each subject, and they were combined into a super set before tensor calculation. The super set included images from all subjects and was useful for group comparisons. We used results obtained from the early registration of a super set for group analysis of tracts using the deterministic fiber-tracking technique. Results In dystonia mutation carriers, we detected fewer fibers in the cerebello-thalamo-cortical pathways. This result agrees well with the findings of a previous study that utilized a probabilistic tractography method and demonstrated that gene carriers have less fiber tracts in the disease-involved pathway. Conclusion This analysis visualized group level white matter fractional anisotropy and tract differences between dystonia patients and controls, and can be useful in understanding the pathophysiology of other nonfocal white matter diseases.

Vo, An; Argyelan, Miklos; Eidelberg, David; Ulugg, Aziz M.

2014-01-01

279

Comparison of setup error using different reference images: a phantom and lung cancer patients study  

SciTech Connect

The purpose of this study was to compare setup errors obtained with kilovoltage cone-beam computed tomography (CBCT) and 2 different kinds of reference images, free-breathing 3D localization CT images (FB-CT) and the average images of 4-D localization CT images (AVG-CT) for phantom and lung cancer patients. This study also explored the correlation between the difference of translational setup errors and the gross tumor volume (GTV) motion. A respiratory phantom and 14 patients were enrolled in this study. For phantom and each patient, 3D helical CT and 4D CT images were acquired, and AVG-CT images were generated from the 4D CT. The setup errors were determined based on the image registration between the CBCT and the 2 different reference images, respectively. The data for both translational and rotational setup errors were analyzed and compared. The GTV centroid movement as well as its correlation with the translational setup error differences was also evaluated. In the phantom study, the AVG-CT method was more accurate than the FB-CT method. For patients, the translational setup errors based on FB-CT were significantly larger than those from AVG-CT in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP) directions (p < 0.05). Translational setup errors differed by >1 mm in 32.6% and >2 mm in 12.9% of CBCT scans. The rotational setup errors from FB-CT were significantly different from those from AVG-CT in the LR and AP directions (p < 0.05). The correlation coefficient of the translational setup error differences and the GTV centroid movement in the LR, SI, and AP directions was 0.515 (p = 0.060), 0.902 (p < 0.001), and 0.510 (p = 0.062), respectively. For lung cancer patients, respiration may affect the on-line target position location. AVG-CT provides different reference information than FB-CT. The difference in SI direction caused by the 2 methods increases with the GTV movement. Therefore, AVG-CT should be the prefered choice of reference images.

Jiang Bo [Department of Radiation Oncology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing (China); Dai Jianrong, E-mail: jiangbo122@126.com [Department of Radiation Oncology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing (China); Zhang Ye; Zhang Ke; Men Kuo; Zhou Zongmei; Liang Jun; Wang Lvhua [Department of Radiation Oncology, Cancer Institute (Hospital), Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing (China)

2012-04-01

280

Changes of brain anatomy in patients with posttraumatic stress disorder: A pilot magnetic resonance imaging study  

Microsoft Academic Search

No abnormalities in magnetic resonance images were recorded in patients with posttraumatic stress disorder other than an increased incidence (50%) of a small cleft in the callosal-septal interface, a cavum of the septum pellucidum. A similar grade of cavum was obtained in 14% of normal volunteers matched for age, socioeconomic background, and military experience. The cavum is believed to have

Michael S. Myslobodsky; Joseph Glicksohn; Jaffa Singer; Max Stern; Jacob Bar-Ziv; Nehemia Friedland; Avi Bleich

1995-01-01

281

Imaging of a carotid aneurysm in two patients following extracorporeal membrane oxygenation therapy.  

PubMed

Following extracorporeal membrane oxygenation (ECMO), two patients subsequently developed carotid aneurysms at the site of cannulation. Given the invasive nature of ECMO, vascular ultrasound and/or computerized tomographic imaging should be considered to rule out cannulation-site complications post-ECMO. PMID:19471993

Duncan, Andrew W; Mawson, John B; LeBlanc, Jacques G; Potts, James E; Duncan, Walter J

2009-10-01

282

Drug evaluation: Lymphoseek - Neoprobe's sentinel lymph node imaging agent for use in cancer patients.  

PubMed

Neoprobe, under license from the University of California San Diego Cancer Center, is developing 99mTc-DTPA-mannosyl-dextran (Lymphoseek) as a potential agent for imaging lymph nodes in patients undergoing treatment for breast cancer and melanoma. Phase II trials of Lymphoseek were initiated in mid 2006. PMID:17209528

de Paulis, Tomas

2006-12-01

283

Dopamine and serotonin transporters in patients with schizophrenia: an imaging study with [ 123I]?-CIT  

Microsoft Academic Search

Background: Several lines of evidence derived from imaging and postmortem studies suggest that schizophrenia is associated with hyperactivity of dopamine function and deficiency in serotonin (5-HT) function. The aim of this study was to investigate potential alterations of striatal dopamine transporters (DAT) and brainstem serotonin transporters (SERT) density in schizophrenia.Methods: Striatal DAT and brainstem SERT were measured in 24 patients

Marc Laruelle; Anissa Abi-Dargham; Christopher van Dyck; Roberto Gil; D. Cyril D’Souza; John Krystal; John Seibyl; Ronald Baldwin; Robert Innis

2000-01-01

284

Modulation of brain response to emotional images by alcohol cues in alcohol-dependent patients  

Microsoft Academic Search

Alcohol is often used to modulate mood states. Alcohol drinkers report that they use alcohol both to enhance positive affect and to reduce dysphoria, and alcohol-dependent patients specifically state reduction of negative affect as a primary reason for drinking.The current study proposes that alcohol cues may reduce negative affect in alcoholics. We used functional magnetic resonance imaging to examine brain

Jodi M. Gilman; Daniel W. Hommer

2008-01-01

285

Functional brain abnormalities localized in 55 chronic tinnitus patients: fusion of SPECT coincidence imaging and MRI  

Microsoft Academic Search

Tinnitus is often defined as the perception of sounds or noise in the absence of any external auditory stimuli. The pathophysiology of subjective idiopathic tinnitus remains unclear. The aim of this study was to investigate the functional brain activities and possible involved cerebral areas in subjective idiopathic tinnitus patients by means of single photon emission computerized tomography (SPECT) coincidence imaging,

Mohammad Farhadi; Saeid Mahmoudian; Fariba Saddadi; Ali Reza Karimian; Mohammad Mirzaee; Majid Ahmadizadeh; Khosro Ghasemikian; Saeid Gholami; Esmaeel Ghoreyshi; Saeid Beyty; Ahmadreza Shamshiri; Sedighe Madani; Valery Bakaev; Seddighe Moradkhani; Gholamreza Raeisali

2010-01-01

286

Is Routine Pelvic Surveillance Imaging Necessary in Patients with Wilms' Tumor?  

PubMed Central

Background It is unclear if routine pelvic imaging is needed in patients with Wilms’ tumor. Thus, our primary objective examined the role of routine pelvic computed tomography (CT) in a cohort of pediatric patients with Wilms’ tumor. Methods With IRB approval we retrospectively identified 110 Wilms’ tumor patients diagnosed between January 1999 and December 2009; surveillance imaging continued through March 2011. We estimated survival (OS) and event-free survival (EFS), and dosimetry from dose length product (DLP) conversion to effective dose (ED) for every CT in a subgroup of 80 patients scanned using contemporary scanners (2002–2011). MOSFET dosimeters were placed within organs of anthropomorphic phantoms to directly calculate truncal ED. EDDLP was correlated with EDMOSFET to calculate potential pelvic dose savings. Results Eighty patients underwent 605 CT examinations containing DLP information: 352 chest, abdomen and pelvis, 123 chest-abdomen, 102 chest only, 18 abdomen-pelvis, 9 abdomen only, one limited to pelvis. Respective 5-year OS and EFS estimates were 92.8% ± 3.0% and 2.6% ± 4.3%. Sixteen patients (16/110; 15%) relapsed a median of 11.3 months (range, 5.0 months to 7.3 years) after diagnosis; four died of disease recurrence. Three patients developed pelvic relapse, all symptomatic. Estimated ED savings from gender-neutral CT surveillance performed at 120 kVp without pelvic imaging was calculated: 30.5%, 30.4%, 39.4%, and 44.9% for the average 1, 5, 10, and 15 year old patient, respectively. Conclusions Omitting pelvic CT from routine off-therapy follow-up of Wilms’ tumor patients saves an average 30–45% effective dose without compromising disease detection.

Kaste, Sue C.; Brady, Samuel L.; Yee, Brian; McPherson, Valerie J.; Kaufman, Robert A.; Billups, Catherine A.; Daw, Najat C.; Pappo, Alberto S.

2012-01-01

287

Clinical findings and imaging features of 67 nasopharyngeal carcinoma patients with postradiation nasopharyngeal necrosis  

PubMed Central

Postradiation nasopharyngeal necrosis is an important late effect of radiotherapy that affects prognosis in patients with nasopharyngeal carcinoma. In the present study, we reviewed the clinical and imaging features of 67 patients with pathologically diagnosed postradiation nasopharyngeal necrosis who were treated at Sun Yat-sen University Cancer Center between June 2006 and January 2010. Their clinical manifestations, endoscopic findings, and imaging features were analyzed. Early nasopharyngeal necrosis was limited to a local site in the nasopharyngeal region, and the tissue defect was not obvious, whereas deep parapharyngeal ulcer or signs of osteoradionecrosis in the basilar region was observed in serious cases. Those with osteoradionecrosis and/or exposed carotid artery had a high mortality. In conclusion, Postradiation nasopharyngeal necrosis has characteristic magnetic resonance imaging appearances, which associate well with clinical findings, but pathologic examination is essential to make the diagnosis.

Chen, Ming-Yuan; Mai, Hai-Qiang; Sun, Rui; Guo, Xiang; Zhao, Chong; Hong, Ming-Huang; Hua, Yi-Jun

2013-01-01

288

Image-based electronic patient records for secured collaborative medical applications.  

PubMed

We developed a Web-based system to interactively display image-based electronic patient records (EPR) for secured intranet and Internet collaborative medical applications. The system consists of four major components: EPR DICOM gateway (EPR-GW), Image-based EPR repository server (EPR-Server), Web Server and EPR DICOM viewer (EPR-Viewer). In the EPR-GW and EPR-Viewer, the security modules of Digital Signature and Authentication are integrated to perform the security processing on the EPR data with integrity and authenticity. The privacy of EPR in data communication and exchanging is provided by SSL/TLS-based secure communication. This presentation gave a new approach to create and manage image-based EPR from actual patient records, and also presented a way to use Web technology and DICOM standard to build an open architecture for collaborative medical applications. PMID:17282930

Zhang, Jianguo; Sun, Jianyong; Yang, Yuanyuan; Liang, Chenwen; Yao, Yihong; Cai, Weihua; Jin, Jin; Zhang, Guozhen; Sun, Kun

2005-01-01

289

Are maladaptive schema domains and perfectionism related to body image concerns in eating disorder patients?  

PubMed

Both maladaptive schemas (MS) and perfectionism have been associated with eating pathology. However, previous research has not examined these variables simultaneously and has not studied possible mediating relationships between MS and multidimensional perfectionism for body image concerns in eating disorder (ED) patients. Eighty-eight female ED patients completed the Young Schema Questionnaire, the Frost Multidimensional Perfectionism Scale, and the Body Attitude Test. Body image concerns were found to be positively related to Personal Standards (PS) and Evaluative Concerns (EC) perfectionism and all five schema domains. PS Perfectionism was positively associated with Disconnection, Other-directedness, and Overvigilance. EC Perfectionism was positively related to Disconnection, Impaired Autonomy, Other-directedness, and Overvigilance. Moreover, EC perfectionism was found to be a significant mediator in the relationship between the schema domains Impaired Autonomy and Overvigilance and body image concerns. These findings denote the importance to address both core beliefs and perfectionism in ED treatment. PMID:22556040

Boone, Liesbet; Braet, Caroline; Vandereycken, Walter; Claes, Laurence

2013-01-01

290

Balancing dose and image registration accuracy for cone beam tomosynthesis (CBTS) for breast patient setup  

SciTech Connect

Purpose: To balance dose reduction and image registration accuracy in breast setup imaging. In particular, the authors demonstrate the relationship between scan angle and dose delivery for cone beam tomosynthesis (CBTS) when employed for setup verification of breast cancer patients with surgical clips. Methods: The dose measurements were performed in a female torso phantom for varying scan angles of CBTS. Setup accuracy was measured using three registration methods: Clip centroid localization accuracy and the accuracy of two semiautomatic registration algorithms. The dose to the organs outside of the ipsilateral breast and registration accuracy information were compared to determine the optimal scan angle for CBTS for breast patient setup verification. Isocenter positions at the center of the patient and at the breast-chest wall interface were considered. Results: Image registration accuracy was within 1 mm for the CBTS scan angles {theta} above 20 deg. for some scenarios and as large as 80 deg. for the worst case, depending on the imaged breast and registration algorithm. Registration accuracy was highest based on clip centroid localization. For left and right breast imaging with the isocenter at the chest wall, the dose to the contralateral side of the patient was very low (<0.5 cGy) for all scan angles considered. For central isocenter location, the optimal scan angles were 30 deg. - 50 deg. for the left breast imaging and 40 deg. - 50 deg. for the right breast imaging, with the difference due to the geometric asymmetry of the current clinical imaging system. Conclusions: The optimal scan angles for CBTS imaging were found to be between 10 deg. and 50 deg., depending on the isocenter location and ipsilateral breast. Use of the isocenter at the breast-chest wall locations always resulted in greater accuracy of image registration (<1 mm) at smaller angles (10 deg. - 20 deg.) and at lower doses (<0.1 cGy) to the contralateral organs. For chest wall isocenters, doses delivered to organs outside of the target breast were much smaller than the scattered and leakage doses of the treatment beams. The complete volumetric information of all clips in the region of interest, combined with the small dose to the contralateral organs and the small scan angle, could result in an advantage for small angle CBTS with off center isocenters over simple orthogonal pairs.

Winey, B. A.; Zygmanski, P.; Cormack, R. A.; Lyatskaya, Y. [Department of Radiation Oncology, Dana-Farber/Brigham and Women's Cancer Center, Harvard Medical School, Boston, Massachusetts 02115 (United States)

2010-08-15

291

[Roentgen image presentation in the patient's room. Simple equipment for demonstration and storage of roentgen images].  

PubMed

Immediate presentation of the more significant X-ray pictures facilitates planning and supervision of therapy in trauma surgery and orthopedics. If a wire rope is stretched in front of the window X-ray pictures can be clipped onto it, which avoids time-consuming searches. Suspended filing boxes placed in each sickroom make appropriate storage of each patient's X-ray pictures possible. The expenditure for all this amounted to 100 DM for each two-bedded room. Wire ropes and boxes were technically easy to install with a minimum investment of time. The presentation of X-ray pictures considerably increased the patients' understanding of their illness. It was also very rare for X-ray pictures to get mixed up once this system had been instituted. PMID:9082570

Prokop, A; Rehm, K E; Sagebiel, A

1996-12-01

292

Patterns of disease activity in multiple sclerosis: clinical and magnetic resonance imaging study  

Microsoft Academic Search

OBJECTIVE--To compare the abnormalities shown by magnetic resonance imaging of the brain in three clinically distinct groups of patients with multiple sclerosis, and to correlate the extent of abnormality with the degree of clinical disability in the three groups. DESIGN--All patients underwent magnetic resonance imaging and full neurological examination, and their disability was scored according to the expanded Kurtzke disability

A J Thompson; A G Kermode; D G MacManus; B E Kendall; D P Kingsley; I F Moseley; W I McDonald

1990-01-01

293

Shaped, lead-loaded acrylic filters for patient exposure reduction and image-quality improvement  

SciTech Connect

Shaped filters that are constructed of lead-loaded acrylic material for use in patient radiography are discussed. Use of the filters will result in improved overall image quality with significant exposure reduction to the patient (approximately a 2X reduction in breast exposure and a 3X reduction in thyroid gland exposure). Detailed drawings of the shaped filters for scoliosis radiography, cervical spine radiography, and for long film changers in special procedures are provided. The use of the scoliosis filters is detailed and includes phantom and patient radiographs and dose reduction information.

Gray, J.E.; Stears, J.G.; Frank, E.D.

1983-03-01

294

A contextual based double watermarking of PET images by patient ID and ECG signal.  

PubMed

This paper presents a novel digital watermarking framework using electrocardiograph (ECG) and demographic text data as double watermarks. It protects patient medical information and prevents mismatching diagnostic information. The watermarks are embedded in selected texture regions of a PET image using multi-resolution wavelet decomposition. Experimental results show that modifications in these locations are visually imperceptible. The robustness of the watermarks is verified through measurement of peak signal to noise ratio (PSNR), cross-correlation (CC%), structural similarity measure (SSIM) and universal image quality index (UIQI). Their robustness is also computed using pixel-based metrics and human visual system metrics. Additionally, beta factor (?) as an edge preservation measure is used for degradation evaluation of the image boundaries throughout the watermarked PET image. Assessment of the extracted watermarks shows watermarking robustness to common attacks such as embedded zero-tree wavelet (EZW) compression and median filtering. PMID:20934773

Nambakhsh, Mohammad-Saleh; Ahmadian, Alireza; Zaidi, Habib

2011-12-01

295

Indium-111 chloride imaging in patients with suspected abscesses: concise communication  

SciTech Connect

Two hundred and fifty-eight patients with clinically suspected inflammatory processes were studied. Seventy-two images were categorized as true positive; 211 as true negative. There were nine false-positive studies, four of which were due to activity in beds of excised organs. There were six false-negative studies, four of which were due to walled-off abscesses found either at surgery or biopsy. The sensitivity was 92%, the specificity 95%, and the accuracy 94%. This study shows that indium-111 chloride imaging provides a reliable way to locate inflammatory processes and overcomes the disadvantages of other imaging agents, for example gastrointestinal activity or the demonstration of healing surgical wounds with gallium-67, and the false-positive images due to cystic fibrosis and other respiratory diseases, or accessory spleens as seen with In-111-labeled white cells.

Sayle, B.A.; Balachandran, S.; Rogers, C.A.

1983-12-01

296

Tomographic and planar radionuclide imaging in patients suspected meniscal injury: Arthroscopic correlation  

SciTech Connect

In patients (pts) with knee pain which may be related to meniscal tears, clinical judgment is used to determine whether medical management or arthroscopy is indicated. Based on the assumption that meniscal injury will result in adjacent changes in Tc-99m MDP bone images, studies using both planar and tomographic techniques were performed in 12 pts referred for arthroscopy. Planar imaging was performed in the anterior, posterior, and posterior medial and lateral oblique positions of the symptomatic knee. Single photon emission computed tomography was performed using a 64 view 360/sup 0/ acquisition of both knees. In this series, both imaging techniques were accurate in identifying abnormality, but analysis of transaxial tomographic data showed greater contrast and facilitated localization because of the better spatial orientation provided by this method. Thus, tomographic bone imaging appears valuable in defining areas of localized abnormality in the knees of pts with meniscal injury.

Fajman, W.A.; Diehl, M.; Dunaway, E.; Stephenson, R.; Eisner, R.; Riggins, R.S.; Berger, H.J.

1985-05-01

297

Population of 100 realistic, patient-based computerized breast phantoms for multi-modality imaging research  

NASA Astrophysics Data System (ADS)

Breast imaging is an important area of research with many new techniques being investigated to further reduce the morbidity and mortality of breast cancer through early detection. Computerized phantoms can provide an essential tool to quantitatively compare new imaging systems and techniques. Current phantoms, however, lack sufficient realism in depicting the complex 3D anatomy of the breast. In this work, we created one-hundred realistic and detailed 3D computational breast phantoms based on high-resolution CT datasets from normal patients. We also developed a finiteelement application to simulate different compression states of the breast, making the phantoms applicable to multimodality imaging research. The breast phantoms and tools developed in this work were packaged into user-friendly software applications to distribute for breast imaging research.

Segars, W. Paul; Veress, Alexander I.; Wells, Jered R.; Sturgeon, Gregory M.; Kiarashi, Nooshin; Lo, Joseph Y.; Samei, Ehsan; Dobbins, James T.

2014-03-01

298

The Role of Magnetic Resonance Imaging in Preoperative Planning for Patients Undergoing Therapeutic Mammoplasty  

PubMed Central

Background. Assessment of the ratio between tumour volume and breast volume in therapeutic mammoplasty is paramount. Traditionally based on clinical assessment and conventional breast imaging, the role of breast magnetic resonance imaging (MRI) in this context has not been established. Methods. Data was collected from all women undergoing therapeutic mammoplasty (TM) between 2006 and 2011. Each case was discussed at an MDT where MRI was considered to facilitate surgical planning. The contribution of MRI to disease assessment and surgical outcome was then reviewed. Results. 35 women underwent TM, 15 of whom had additional MRI. 33% of patients within the MRI subgroup had abnormalities not seen on either mammography or USS. Of those undergoing MRI, 1/15 patients required completion mastectomy versus 3 patients requiring completion mastectomy and 1 patient requiring further wide local excision (4/20) in the conventional imaging group. No statistical difference was seen between size on MRI and size on mammography versus final histological size, but a general trend for greater correlation between size on MRI and final histological size was seen. Conclusion. MRI should be considered in selected patients undergoing therapeutic mammoplasty. Careful planning can identify those who are most likely to benefit from MRI, potentially reducing the need for further surgery.

Turton, Philip; Rajan, Sree; Nunn, April; Sharma, Nisha; Achuthan, Raj

2013-01-01

299

Chronic encapsulated expanding hematoma in nonfunctioning pituitary adenoma.  

PubMed

The diagnosis and treatment of pituitary macroadenomas with entire hematoma fluid accumulation are problematic. Such lesions are often difficult to completely resect, and recurrence is not uncommon. We present five cases of pituitary macroadenomas entirely composed of hematoma fluid and investigated their histopathology to clarify the mechanism of the hematoma fluid accumulation. Five patients with pituitary adenoma and significant intra-tumor hematoma underwent transsphenoidal resection and were retrospectively reviewed for their clinical status, findings on magnetic resonance imaging (MRI), intraoperative findings, and histopathology. The specific surgical techniques used to address these cases were also reviewed. All patients were diagnosed with nonfunctioning pituitary adenomas by histopathological examination. MRI showed all tumors extended to the cavernous sinus. Histopathology showed tumor tissues were located between the thick granulation tissue and the pseudocapsule of the tumor. The thick granulation tissues were composed of collagenous layers, neovascular vessels, and necrotic red blood cells, indicating repeat hemorrhage from the granulation tissues. The boundary between adenoma and normal pituitary gland was identified during surgical removal in four patients and was not identified in the other patient who showed a recurrence 2 years later. Clinical and histopathological findings indicate hematoma fluid accumulation in the present cases is caused by repeat hemorrhage from the reactive granulation tissues and can be regarded as a chronic encapsulated expanding hematoma. In these cases, the boundary between adenoma and normal pituitary gland should be identified before puncturing the hematoma fluid to minimize the risk of tumor recurrence. PMID:23345017

Sugawara, Takashi; Aoyagi, Masaru; Tanaka, Youji; Tamaki, Masashi; Kobayashi, Daisuke; Ohno, Kikuo

2013-07-01

300

Posterior Fossa Neurenteric Cysts Can Expand Rapidly: Case Report  

PubMed Central

Neurenteric cysts are considered congenital lesions that may slowly expand over time. Although more commonly found in the spinal canal, they may be found intracranially, particularly in the posterior fossa. Here, we present an unusual case of a large, rapidly expanding histologically confirmed posterior fossa neurenteric cyst in a 53-year-old woman, who presented with quadriparesis. Computed tomography imaging done ~1.5 years before admission failed to demonstrate any obvious abnormality; however, the lesion had grown to 4 cm in maximal dimension at presentation with significant mass effect. The lesion was resected microsurgically using a retrosigmoid approach. The patient improved postoperatively and was neurologically intact at last follow-up. We could find no other documented case of marked, rapid expansion of a neurenteric cyst in the literature. We conclude that, although neurenteric cysts are thought to be congenital, they can undergo rapid expansion even in adults. The mechanism of expansion is unknown but may involve increased secretion, hemorrhage, or inflammation. We discuss the surgical management and review the literature in view of this surprising finding.

Priamo, Francesco A.I.; Jimenez, Elpidio D.; Benardete, Ethan A.

2011-01-01

301

Expanding Patient Options: Minilaparotomy for Hysterectomy  

MedlinePLUS Videos and Cool Tools

... This is something that I can do.” Many times I would have attended conferences and seminars where ... large incisions and prolonged recoveries when it comes time to have your hysterectomy. With that, let me ...

302

Single-Beat Noninvasive Imaging of Ventricular Endocardial and Epicardial Activation in Patients Undergoing CRT  

PubMed Central

Background Little is known about the effect of cardiac resynchronization therapy (CRT) on endo- and epicardial ventricular activation. Noninvasive imaging of cardiac electrophysiology (NICE) is a novel imaging tool for visualization of both epi- and endocardial ventricular electrical activation. Methodology/Principal Findings NICE was performed in ten patients with congestive heart failure (CHF) undergoing CRT and in ten patients without structural heart disease (control group). NICE is a fusion of data from high-resolution ECG mapping with a model of the patient's individual cardiothoracic anatomy created from magnetic resonance imaging. Beat-to-beat endocardial and epicardial ventricular activation sequences were computed during native rhythm as well as during ventricular pacing using a bidomain theory-based heart model to solve the related inverse problem. During right ventricular (RV) pacing control patients showed a deterioration of the ventricular activation sequence similar to the intrinsic activation pattern of CHF patients. Left ventricular propagation velocities were significantly decreased in CHF patients as compared to the control group (1.6±0.4 versus 2.1±0.5 m/sec; p<0.05). CHF patients showed right-to-left septal activation with the latest activation epicardially in the lateral wall of the left ventricle. Biventricular pacing resulted in a resynchronization of the ventricular activation sequence and in a marked decrease of total LV activation duration as compared to intrinsic conduction and RV pacing (129±16 versus 157±28 and 173±25 ms; both p<0.05). Conclusions/Significance Endocardial and epicardial ventricular activation can be visualized noninvasively by NICE. Identification of individual ventricular activation properties may help identify responders to CRT and to further improve response to CRT by facilitating a patient-specific lead placement and device programming.

Berger, Thomas; Pfeifer, Bernhard; Hanser, Friedrich F.; Hintringer, Florian; Fischer, Gerald; Netzer, Michael; Trieb, Thomas; Stuehlinger, Markus; Dichtl, Wolfgang; Baumgartner, Christian; Pachinger, Otmar; Seger, Michael

2011-01-01

303

Reproducibility of patient setup by surface image registration system in conformal radiotherapy of prostate cancer  

PubMed Central

Background The reproducibility of patient setup for radiotherapy is based on various methods including external markers, X-rays with planar or computerized image acquisition, and, more recently, surface matching imaging. We analyzed the setup reproducibility of 16 patients affected by prostate cancer who underwent conformal radiotherapy with curative intent by using a surface image registration system. Methods We analyzed the setup reproducibility of 16 patients affected by prostate cancer candidates for conformal radiotherapy by using a surface image registration system. At the initial setup, EPID images were compared with DRRs and a reference 3D surface image was obtained by the AlignRT system (Vision RT, London, UK). Surface images were acquired prior to every subsequent setup procedure. EPID acquisition was repeated when errors > 5 mm were reported. Results The mean random and systematic errors were 1.2 ± 2.3 mm and 0.3 ± 3.0 mm along the X axis, 0.0 ± 1.4 mm and 0.5 ± 2.0 mm along the Y axis, and 2.0 ± 1.8 mm and -0.7 ± 2.4 mm along the Z axis respectively. The positioning error detected by AlignRT along the 3 axes X, Y, and Z exceeded the value of 5 mm in 14.1%, 2.0%, and 5.1% measurements and the value of 3 mm in 36.9%, 13.6% and 27.8% measurements, respectively. Correlation factors calculated by linear regression between the errors measured by AlignRT and EPID ranged from 0.77 to 0.92 with a mean of 0.85 and SD of 0.13. The setup measurements by surface imaging are highly reproducible and correlate with the setup errors detected by EPID. Conclusion Surface image registration system appears to be a simple, fast, non-invasive, and reproducible method to analyze the set-up alignment in 3DCRT of prostate cancer patients.

Krengli, Marco; Gaiano, Simone; Mones, Eleonora; Ballare, Andrea; Beldi, Debora; Bolchini, Cesare; Loi, Gianfranco

2009-01-01

304

Patient-specific CT dose determination from CT images using Monte Carlo simulations  

NASA Astrophysics Data System (ADS)

Radiation dose from computed tomography (CT) has become a public concern with the increasing application of CT as a diagnostic modality, which has generated a demand for patient-specific CT dose determinations. This thesis work aims to provide a clinically applicable Monte-Carlo-based CT dose calculation tool based on patient CT images. The source spectrum was simulated based on half-value layer measurements. Analytical calculations along with the measured flux distribution were used to estimate the bowtie-filter geometry. Relative source output at different points in a cylindrical phantom was measured and compared with Monte Carlo simulations to verify the determined spectrum and bowtie-filter geometry. Sensitivity tests were designed with four spectra with the same kVp and different half-value layers, and showed that the relative output at different locations in a phantom is sensitive to different beam qualities. An mAs-to-dose conversion factor was determined with in-air measurements using an Exradin A1SL ionization chamber. Longitudinal dose profiles were measured with thermoluminescent dosimeters (TLDs) and compared with the Monte-Carlo-simulated dose profiles to verify the mAs-to-dose conversion factor. Using only the CT images to perform Monte Carlo simulations would cause dose underestimation due to the lack of a scatter region. This scenario was demonstrated with a cylindrical phantom study. Four different image extrapolation methods from the existing CT images and the Scout images were proposed. The results show that performing image extrapolation beyond the scan region improves the dose calculation accuracy under both step-shoot scan mode and helical scan mode. Two clinical studies were designed and comparisons were performed between the current CT dose metrics and the Monte-Carlo-based organ dose determination techniques proposed in this work. The results showed that the current CT dosimetry failed to show dose differences between patients with the same scan parameters. The methodology proposed in this work required simple measurements on the CT scanner for scanner-specific Monte Carlo model establishment, and uses patient CT images to provide patient-specific organ dose calculations. This is an improvement on current CT dosimetry and benefits the patient dose tracking and individual risk estimates.

Liang, Qing

305

EXPANDS: expanding ploidy and allele frequency on nested subpopulations  

PubMed Central

Motivation:?Several cancer types consist of multiple genetically and phenotypically distinct subpopulations. The underlying mechanism for this intra-tumoral heterogeneity can be explained by the clonal evolution model, whereby growth advantageous mutations cause the expansion of cancer cell subclones. The recurrent phenotype of many cancers may be a consequence of these coexisting subpopulations responding unequally to therapies. Methods to computationally infer tumor evolution and subpopulation diversity are emerging and they hold the promise to improve the understanding of genetic and molecular determinants of recurrence. Results:?To address cellular subpopulation dynamics within human tumors, we developed a bioinformatic method, EXPANDS. It estimates the proportion of cells harboring specific mutations in a tumor. By modeling cellular frequencies as probability distributions, EXPANDS predicts mutations that accumulate in a cell before its clonal expansion. We assessed the performance of EXPANDS on one whole genome sequenced breast cancer and performed SP analyses on 118 glioblastoma multiforme samples obtained from TCGA. Our results inform about the extent of subclonal diversity in primary glioblastoma, subpopulation dynamics during recurrence and provide a set of candidate genes mutated in the most well-adapted subpopulations. In summary, EXPANDS predicts tumor purity and subclonal composition from sequencing data. Availability and implementation:?EXPANDS is available for download at http://code.google.com/p/expands (matlab version - used in this manuscript) and http://cran.r-project.org/web/packages/expands (R version). Contact:?claudia.petritsch@ucsf.edu Supplementary information:?Supplementary data are available at Bioinformatics online.

Andor, Noemi; Harness, Julie V.; Muller, Sabine; Mewes, Hans W.; Petritsch, Claudia

2014-01-01

306

The integration of medical images with the electronic patient record and their web-based distribution 1  

Microsoft Academic Search

Medical images are currently created digitally and stored in the radiology department’s picture archiving and communication system. Reports are usually stored in the electronic patient record of other information systems, such as the radiology information system (RIS) and the hospital information system (HIS). But high-quality services can only be provided if electronic patient record data is integrated with digital images

H. Münch; U. Engelmann; A. Schröter; H. P. Meinzer

2004-01-01

307

Functional MR Imaging of Language Processing: An Overview of Easy to-Implement Para digms for Patient Care  

Microsoft Academic Search

Functional magnetic resonance (MR) imaging is one of the most com- monly used functional neuroimaging techniques for studying the cere- bral representation of language processing and is increasingly being used for both patient care and clinical research. In patient care, func- tional MR imaging is primarily used in the preoperative evaluation of (a) the relationship of a lesion to critical

Marion Smits; Evy Visch-Brink; Caroline K. Schraa-Tam; Peter J. Koudstaal; Aad van der Lugt

2006-01-01

308

Thallium-201 versus technetium-99m pyrophosphate myocardial imaging in detection and evaluation of patients with acute myocardial infarction  

SciTech Connect

Thallium-201 myocardial imaging is of value in the early detection and evaluation of patients with suspected acute infarction. Thallium imaging may have a special value in characterizing patients with cardiogenic shock and in detecting patients at risk for subsequent infarction or death or death or both, before hospital discharge. Approximately 95 percent of pateints with transmural or nontransmural myocardial infarction can be detected with technetium-99m pyrophosphate myocardial imaging if the imaging is performed 24 to 72 hours after the onset of symptoms. Pyrophosphate imaging may have an important role in the evaluation of patients during the early follow-up period after hospital discharge from an episode of acute infarction. The finding of a persistently positive pyrophosphate image suggests a poor prognosis and is associated with a relatively large incidence of subsequent myocardial infarction and death.

Pitt, B.; Thrall, J.H.

1980-12-18

309

Comparison of daily megavoltage electronic portal imaging or kilovoltage imaging with marker seeds to ultrasound imaging or skin marks for prostate localization and treatment positioning in patients with prostate cancer  

Microsoft Academic Search

Purpose: To compare the accuracy of imaging modalities, immobilization, localization, and positioning techniques in patients with prostate cancer. Methods and Materials: Thirty-five patients with prostate cancer had gold marker seeds implanted transrectally and were treated with fractionated radiotherapy. Twenty of the 35 patients had limited immobilization; the remaining had a vacuum-based immobilization. Patient positioning consisted of alignment with lasers to

Christopher F.. Serago; Steven J. Buskirk; Todd C. Igel; Ashley A. Gale; Nicole E. Serago; John D. Earle

2006-01-01

310

Circumferential management of unstable thoracolumbar fractures using an anterior expandable cage, as an alternative to an iliac crest graft, combined with a posterior screw fixation: results of a series of 85 patients.  

PubMed

Object The optimal management of unstable thoracolumbar fractures remains unclear. The objective of the present study was to evaluate the results of using an expandable prosthetic vertebral body cage (EPVBC) in the management of unstable thoracolumbar fractures. Methods Eighty-five patients with unstable T7-L4 thoracolumbar fractures underwent implantation of an EPVBC via an anterior approach combined with posterior fixation. Long-term functional outcomes, including visual analog scale and Oswestry disability index scores, were evaluated. Results In a mean follow-up period of 16 months, anterior fixation led to a significant increase in vertebral body height, with an average gain of 19%. However, the vertebral regional kyphosis angle was not significantly increased by anterior fixation alone. No significant difference was found between early postoperative, 3-month, and 1-year postoperative regional kyphosis angle and vertebral body height. Postoperative impaction of the prosthetic cage in adjacent endplates was observed in 35% of the cases, without worsening at last follow-up. Complete fusion was observed at 1 year postoperatively and no cases of infections or revisions were observed in relation to the anterior approach. Conclusions The use of EPVBCs for unstable thoracolumbar fractures is safe and effective in providing long-term vertebral body height restoration and kyphosis correction, with a moderate surgical and sepsis risk. Anterior cage implantation is an alternative to iliac bone graft fusion and is a viable option in association with a posterior approach, in a single operation without additional risks. PMID:24981898

Graillon, Thomas; Rakotozanany, Patrick; Blondel, Benjamin; Adetchessi, Tarek; Dufour, Henry; Fuentes, Stéphane

2014-07-01

311

Fast Monte Carlo simulation for patient-specific CT/CBCT imaging dose calculation.  

PubMed

X-ray imaging dose from computed tomography (CT) or cone beam CT (CBCT) scans has become a serious concern. Patient-specific imaging dose calculation has been proposed for the purpose of dose management. While Monte Carlo (MC) dose calculation can be quite accurate for this purpose, it suffers from low computational efficiency. In response to this problem, we have successfully developed a MC dose calculation code, gCTD, on GPU architecture under the NVIDIA CUDA platform for fast and accurate estimation of the x-ray imaging dose received by a patient during a CT or CBCT scan. Techniques have been developed particularly for the GPU architecture to achieve high computational efficiency. Dose calculations using CBCT scanning geometry in a homogeneous water phantom and a heterogeneous Zubal head phantom have shown good agreement between gCTD and EGSnrc, indicating the accuracy of our code. In terms of improved efficiency, it is found that gCTD attains a speed-up of ?400 times in the homogeneous water phantom and ?76.6 times in the Zubal phantom compared to EGSnrc. As for absolute computation time, imaging dose calculation for the Zubal phantom can be accomplished in ?17 s with the average relative standard deviation of 0.4%. Though our gCTD code has been developed and tested in the context of CBCT scans, with simple modification of geometry it can be used for assessing imaging dose in CT scans as well. PMID:22222686

Jia, Xun; Yan, Hao; Gu, Xuejun; Jiang, Steve B

2012-02-01

312

Fast Monte Carlo simulation for patient-specific CT/CBCT imaging dose calculation  

NASA Astrophysics Data System (ADS)

X-ray imaging dose from computed tomography (CT) or cone beam CT (CBCT) scans has become a serious concern. Patient-specific imaging dose calculation has been proposed for the purpose of dose management. While Monte Carlo (MC) dose calculation can be quite accurate for this purpose, it suffers from low computational efficiency. In response to this problem, we have successfully developed a MC dose calculation code, gCTD, on GPU architecture under the NVIDIA CUDA platform for fast and accurate estimation of the x-ray imaging dose received by a patient during a CT or CBCT scan. Techniques have been developed particularly for the GPU architecture to achieve high computational efficiency. Dose calculations using CBCT scanning geometry in a homogeneous water phantom and a heterogeneous Zubal head phantom have shown good agreement between gCTD and EGSnrc, indicating the accuracy of our code. In terms of improved efficiency, it is found that gCTD attains a speed-up of ?400 times in the homogeneous water phantom and ?76.6 times in the Zubal phantom compared to EGSnrc. As for absolute computation time, imaging dose calculation for the Zubal phantom can be accomplished in ?17 s with the average relative standard deviation of 0.4%. Though our gCTD code has been developed and tested in the context of CBCT scans, with simple modification of geometry it can be used for assessing imaging dose in CT scans as well.

Jia, Xun; Yan, Hao; Gu, Xuejun; Jiang, Steve B.

2012-02-01

313

Atypical teratoid/rhabdoid tumors in adult patients: CT and MR imaging features.  

PubMed

Primary AT/RT is a rare highly malignant tumor of the CNS, usually occurring in children younger than 5 years of age. The objective of this study was to characterize the CT and MR imaging findings in a series of 5 adult patients with pathologically proved AT/RT. All 5 AT/RTs were supratentorial. In 2 patients who underwent nonenhanced CT, the tumors appeared isoattenuated, and 1 of the 2 tumors contained calcifications. Solid portions of the tumors on MR imaging were isointense on T1-weighted, T2-weighted, and FLAIR images, and 1 case showed restricted diffusion on DWI. The tumors also demonstrated a bandlike rim of strong enhancement surrounding a central cystic area on contrast-enhanced T1-weighted imaging. One tumor was associated with destruction of the calvaria. Although AT/RTs can have nonspecific findings, the tumors in our series were large and isointense on T1-weighted, T2-weighted, and FLAIR images with central necrosis and prominent rim enhancement. PMID:21051520

Han, L; Qiu, Y; Xie, C; Zhang, J; Lv, X; Xiong, W; Wang, W; Zhang, X; Wu, P

2011-01-01

314

Usefulness of bidimensional strain imaging for predicting outcome in asymptomatic patients aged ? 16 years with isolated moderate to severe aortic regurgitation.  

PubMed

Aortic regurgitation (AR) has increased in the pediatric population because of the expanded use of new surgical and hemodynamic procedures. Unfortunately, the exact timing for operation in patients with AR is still debated. Conventional echocardiographic parameters, left ventricular (LV) dimensions and the LV ejection fraction, have limitations in predicting early LV dysfunction. Two-dimensional strain imaging, an emerging ultrasound technology, has the potential to better study those patients. The aim of this study was to assess the prognostic value of 2-dimensional longitudinal strain in young patients with congenital isolated moderate to severe AR. Twenty-six young patients with asymptomatic AR (aged 3 to 16 years) were studied. The mean follow-up duration was 2.9 ± 1.2 years (range 0.5 to 6). Baseline LV function by speckle-tracking and conventional echocardiography in patients with stable disease was compared with that in patients with progressive AR (defined as development of symptoms, increase in LV volume ?15%, or decrease in the LV ejection fraction ?10% during follow-up). LV ejection fractions were similar between groups. The jet area/LV outflow tract area ratio was significantly increased in patients with AR with progressive disease (31.2 ± 5.6% vs 39.2 ± 3.8%, p <0.001). The peak transmitral early velocity/early diastolic mitral annular velocity ratio was significantly increased in patients with progressive AR (p = 0.001). LV average longitudinal strain was significantly reduced in patients with progressive AR compared to those with stable AR (-17.8 ± 3.9% vs -22.7 ± 2.7%, p = 0.001). On multivariate analysis, the only significant risk factor for progressive AR was average LV longitudinal strain (p = 0.04, cut-off value >-19.5%, sensitivity 77.8%, specificity 94.1%, area under the curve 0.889). In conclusion, 2-dimensional strain imaging can discriminate young asymptomatic patients with progressive AR. This could allow young patients with AR to have a better definition of surgical timing before the occurrence of irreversible myocardial damage. PMID:22728004

Di Salvo, Giovanni; Rea, Alessandra; Mormile, Annunziata; Limongelli, Giuseppe; D'Andrea, Antonello; Pergola, Valeria; Pacileo, Giuseppe; Caso, Pio; Calabrò, Raffaele; Russo, Maria Giovanna

2012-10-01

315

Magnetic resonance imaging in patients with newly diagnosed breast cancer: A review of the literature.  

PubMed

The use of magnetic resonance imaging (MRI) in patients with newly diagnosed breast cancer remains controversial. Here we review the current use of breast MRI and the impact of MRI on short-term surgical outcomes and rates of local recurrence. In addition, we address the use of MRI in specific patient populations, such as those with ductal carcinoma in situ, invasive lobular carcinoma, and occult primary breast cancer, and discuss the potential role of MRI for assessing response to neoadjuvant chemotherapy. Although MRI has improved sensitivity compared with conventional imaging, this has not translated into improved short-term surgical outcomes or long-term patient benefit, such as improved local control or survival, in any patient population. MRI is an important diagnostic test in the evaluation of patients presenting with occult primary breast cancer and has shown promise in monitoring response to neoadjuvant chemotherapy; however, the data do not support the routine use of perioperative MRI in patients with newly diagnosed breast cancer. Cancer 2014;120:120:2080-2089. © 2014 American Cancer Society. PMID:24752817

Pilewskie, Melissa; King, Tari A

2014-07-15

316

Inter- and intra-fraction geometric errors in daily image-guided radiotherapy of free-breathing breast cancer patients measured with continuous portal imaging.  

PubMed

Abstract Background. Daily image-guided radiotherapy (IGRT) using two orthogonal setup images may be inaccurate for breast cancer patients treated in free breathing because the setup images may capture the patient in a breathing phase that is not representative of the mean anatomy. The aim of this study was to quantify the setup errors in breast radiotherapy after image-guided setup correction based on two orthogonal setup images acquired in free breathing. Methods and materials. For 16 breast cancer patients with daily image-pair based IGRT, continuous portal imaging (7.5 Hz) were acquired at each treatment fraction during the delivery of the two tangential fields. For each portal image, the chest wall position relative to the planned position was determined in the imager direction orthogonal to the cranio-caudal direction. It yielded the time resolved setup error in this direction throughout the 16 treatment courses. Results. The mean absolute setup error exceeded 5 mm in 0.9% (first field) and 1.8% (last field) of the treatments. The group mean error (M) and the standard deviations of the random (?) and systematic (?) setup errors were M = - 0.7 mm, ? = 1.1 mm, ? = 1.5 mm (first field) and M = - 0.2 mm, ? = 1.4 mm, ? = 1.7 mm (last field). The negative sign of M indicates that less lung than planned was included in the treatment fields. Intra-field peak-to-peak chest wall motion amplitudes were patient dependent with patient mean values of 2.0 ± 0.7 mm [range 1.1-3.2 mm]. The largest observed intra-field motion amplitude was 8 mm. Conclusion. Image-guided setup based on orthogonal planar images acquired in free breathing without synchronization with the respiratory phase was found to result in accurate tangential breast radiotherapy with only few outliers. PMID:24739061

Thomsen, Mette S; Harrov, Ulla; Fledelius, Walther; Poulsen, Per R

2014-06-01

317

Using patient-specific phantoms to evaluate deformable image registration algorithms for adaptive radiation therapy  

PubMed Central

The quality of adaptive treatment planning depends on the accuracy of its underlying deformable image registration (DIR). The purpose of this study is to evaluate the performance of two DIR algorithms, B-spline–based deformable multipass (DMP) and deformable demons (Demons), implemented in a commercial software package. Evaluations were conducted using both computational and physical deformable phantoms. Based on a finite element method (FEM), a total of 11 computational models were developed from a set of CT images acquired from four lung and one prostate cancer patients. FEM generated displacement vector fields (DVF) were used to construct the lung and prostate image phantoms. Based on a fast-Fourier transform technique, image noise power spectrum was incorporated into the prostate image phantoms to create simulated CBCT images. The FEM-DVF served as a gold standard for verification of the two registration algorithms performed on these phantoms. The registration algorithms were also evaluated at the homologous points quantified in the CT images of a physical lung phantom. The results indicated that the mean errors of the DMP algorithm were in the range of 1.0 ~ 3.1 mm for the computational phantoms and 1.9 mm for the physical lung phantom. For the computational prostate phantoms, the corresponding mean error was 1.0–1.9 mm in the prostate, 1.9–2.4 mm in the rectum, and 1.8–2.1 mm over the entire patient body. Sinusoidal errors induced by B-spline interpolations were observed in all the displacement profiles of the DMP registrations. Regions of large displacements were observed to have more registration errors. Patient-specific FEM models have been developed to evaluate the DIR algorithms implemented in the commercial software package. It has been found that the accuracy of these algorithms is patient-dependent and related to various factors including tissue deformation magnitudes and image intensity gradients across the regions of interest. This may suggest that DIR algorithms need to be verified for each registration instance when implementing adaptive radiation therapy.

Stanley, Nick; Glide-Hurst, Carri; Kim, Jinkoo; Adams, Jeffrey; Li, Shunshan; Wen, Ning; Chetty, Indrin J.; Zhong, Hualiang

2014-01-01

318

Magnetic resonance imaging in patients with nipple discharge: should we recommend it?  

Microsoft Academic Search

Objectives  Comparing the sensitivity of Contrast-Enhanced Magnetic Resonance Imaging (CEMRI), mammography and ultrasonography in patients\\u000a with nipple discharge (ND).\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We retrospectively evaluated 38 women with ND who underwent mammography, ultrasound and 1.5 T CEMRI between March 2007 and\\u000a July 2009. Imaging findings, pathological diagnosis and follow-up data (mean follow-up: 20 months) were compared. Sensitivity\\u000a and specificity values were reckoned. Statistical differences in sensitivity

Michele Lorenzon; Chiara Zuiani; Anna Linda; Viviana Londero; Rossano Girometti; Massimo Bazzocchi

2011-01-01

319

An adult patient with left ventricular noncompaction detected on radionuclide myocardial perfusion imaging.  

PubMed

Left ventricular noncompaction (LVNC) is a rare congenital disease. We herein present less common single photon emission computed tomography (SPECT) images of myocardial perfusion in an adult patient with LVNC. The images revealed segmental and seriously decreased myocardial perfusion with moderate enlargement of the left ventricle. Quantitative electrocardiogram-gated SPECT showed a moderately decreased left ventricular ejection fraction with impaired contractions. The SPECT findings were very similar to those of ischemic cardiomyopathy (ICM). Cardiac magnetic resonance (CMR) and echocardiography confirmed the diagnosis of LVNC. Physicians should be aware of this uncommon cardiomyopathy and conduct comprehensive analyses in order to make a better differential diagnosis. PMID:23503407

Li, Jian-Ming; Li, Ting; Xu, Dong-Sheng; Shi, Rong-Fang

2013-01-01

320

Magnetic resonance imaging in the follow-up of patients after aortic root reconstruction.  

PubMed

Long-term survival after replacement of the aortic root with a composite graft is improving. Late deaths are in several cases due to complications related to the previous surgery or to pathologies of the remaining aorta. Regular follow-up of these patients is of paramount importance. The purpose of this study is to evaluate the reliability of magnetic resonance imaging (MRI) in such cases. Twenty-seven patients (9 dissections and 18 aneurysms) who had undergone replacement of the aortic root with a composite graft were studied 20 to 167 months after surgery using magnetic resonance imaging with a 1.5 Tesla magnet. The left-ventricular outflow tract, the mechanical valve function, the proximal part of the coronary arteries, the graft, and the remaining aorta could be examined. No aortic insufficiency, ectasy of the proximal part of the coronaries, or pseudoaneurysms were seen. A widening of the remaining ascending aorta was noted in 4 cases. A still open, dissected pipe was visualized in 7 patients. Our conclusions are that MRI provides excellent images of the thoracic and abdominal aorta following surgical repair. The examination is becoming cost-competitive. More import is its very low risk for the patient group considered here: since it is non-invasive and requires no contrast medium or X-ray exposure, examinations can be repeated as required. PMID:8896161

Lepore, V; Lamm, C; Bugge, M; Larsson, S

1996-08-01

321

Recovery mechanisms of somatosensory function in stroke patients: implications of brain imaging studies.  

PubMed

Somatosensory dysfunction is associated with a high incidence of functional impairment and safety in patients with stroke. With developments in brain mapping techniques, many studies have addressed the recovery of various functions in such patients. However, relatively little is known about the mechanisms of recovery of somatosensory function. Based on the previous human studies, a review of 11 relevant studies on the mechanisms underlying the recovery of somatosensory function in stroke patients was conducted based on the following topics: (1) recovery of an injured somatosensory pathway, (2) peri-lesional reorganization, (3) contribution of the unaffected somatosensory cortex, (4) contribution of the secondary somatosensory cortex, and (5) mechanisms of recovery in patients with thalamic lesions. We believe that further studies in this field using combinations of diffusion tensor imaging, functional neuroimaging, and magnetoencephalography are needed. In addition, the clinical significance, critical period, and facilitatory strategies for each recovery mechanism should be clarified. PMID:23471867

Jang, Sung Ho

2013-06-01

322

[Characterization of muscular involvement in patients with Duchenne muscular dystrophy by magnetic resonance imaging].  

PubMed

OBJECTIVE To study the order and degree of muscular affection in patients with Duchenne muscular dystrophy (DMD) during the course of disease. METHODS Multiplex ligation dependent probe amplification (MLPA) was used to detect potential mutation of dystrophin gene. Magnetic resonance imaging (MRI) was used to scan the anteromedial aspect of thigh muscles. RESULTS All of the 6 patients were found to have deletion or duplication mutations. The order of affection has been gluteus maximus, adductor magnus, quadriceps femoris, rectus femoris and biceps muscle of the thigh, while semimembranous muscle, semitendinosus, sartorius muscle and musculus gracilis are selectively affected and in a decreasing order. CONCLUSION MRI can reflect the order, extent and degree of skeletal muscle involvement in patients with DMD, and can reflect pathological changes of damaged skeletal muscle at each stage, which may provide an important means for patient examination and diagnosis. No apparent correlation between the severity of disease and the nature of mutations was noted. PMID:24928023

Chen, Wei; Feng, Shanwei; Feng, Huiyu; Zhang, Cheng

2014-06-10

323

Management of patients with incidental findings in imaging tests: a large prospective single-center study.  

PubMed

We prospectively followed up patients with an incidental finding detected in an image test to assess the additional interventions carried out and the clinical implications of the incidental findings detected. Out of 474 patients with an incidental finding, 63 (13.3%) were further evaluated, and of these patients, 25 (39.7%) had clinical implications. Patients who had an X-ray (24/76, 31.6%), with a preoperative examination (19/77 24.7%), and with an incidental finding in the thoracic cavity (34/117, 29.1%) or in the head/neck (6/28, 21.4%) were more likely to have additional evaluations. PMID:24560749

Lumbreras, Blanca; González-Alvarez, Isabel; Gómez-Sáez, Noemi; Lorente, M Fermina; Hernández-Aguado, Ildefonso

2014-01-01

324

Cardiac magnetic resonance imaging in daily practice in a peripheral medical centre: description of the first 383 patients  

PubMed Central

Background Cardiac magnetic resonance (CMR) imaging has evolved over the last decade into an indispensable diagnostic instrument. CMR imaging noninvasively provides structural, functional and morphological information with high spatial resolution and an unlimited field of view. Since October 2006 the VieCuri Medical Centre in Venlo has a CMR scanner at its disposal. Objectives The goal of this study was to analyse the impact of CMR imaging on diagnosis and treatment in daily practice in the setting of a medium-volume peripheral hospital. Methods All patients who underwent CMR imaging between October 2006 and November 2008 were included in this analysis. The medical history before and after the CMR scan, the application form for CMR imaging and the outcome of the scans were reviewed. CMR images, obtained using a 1.5-T magnetic resonance imaging system, were reviewed by a multidisciplinary team. Results In 235 patients CMR imaging demonstrated one or more abnormalities, whereas CMR imaging did not identify any abnormalities in 148 patients. CMR imaging confirmed an expected finding in 166 cases, identified an unexpected condition in 69 cases, ruled out an expected finding in 59 cases and ruled out a suspected condition in 89 cases. Due to better insight into diagnosis, CMR imaging resulted in a change of treatment in 166 of the total of 383 CMR scans (43%). Conclusion In a relevant number of cases CMR imaging leads to a change in the treatment of a patient, proving the value of CMR imaging as a diagnostic modality. Therefore, CMR imaging is an excellent opportunity for peripheral medical centres to improve efficiency and the standard of patient care. (Neth Heart J 2010;18:524–30.)

Lexis, C.P.H.; Rahel, B.M.; van Langen, H.; Lexis, M.A.S.; Hoffland, G.A.; Post, P.J.M.; Meeder, J.G.

2010-01-01

325

Impact of thallium-201 imaging on clinical assessment and management of patients with chest pain  

SciTech Connect

The histories, rest, and exercise ECG results of 60 patients without myocardial infarction complaining of chest pain were submitted to 6 physicians (3 cardiologists and 3 noncardiologists) who were unaware of the angiographic findings. The physicians were requested to estimate the probability of coronary artery disease present in percentages and to assess the need for coronary angiography on a five-point scale (1 . definitely not indicated, 5 . definitely indicated). After obtaining the results of thallium-201 imaging following dipyridamole (0.50 mg/kg intravenously) administration, the physicians were again requested to estimate probability and need for angiography. In the 43 patients with coronary artery disease the judgment of probability was increased significantly after /sup 201/Tl from 75.6 +/- 20.2% to 82.9 +/- 23.2% (p less than 0.001) and the need for angiography from 4.3 +/- 0.9% to 4.5 +/- 0.9% (p less than 0.001). In the subgroup of patients with atypical angina the relative change in probability was higher than in other subgroups of patients with coronary artery disease. In the 17 patients with normal coronary arteries the probability estimation fell after /sup 201/Tl from 36.7 +/- 22.0% to 24.8 +/- 21.0% (p less than 0.001), the need for angiography was decreased from 2.7 +/- 1.1% to 2.2 +/- 1.2% (p less than 0.001). With the /sup 201/Tl information, cardiologists performed a better diagnostic differentiation of patients with and without coronary artery disease than noncardiologists. The study demonstrates the improvement of clinical diagnosis in patients with chest pain by thallium-201 imaging and confirms the favorable influence of the method on the management of the patients in terms of indications for coronary angiography.

Schmoliner, R.; Dudczak, R.; Kronik, G.; Moesslacher, H.; Zangeneh, M.; Pollak, C.; Schurz, B.; Schoberwalter, A.

1984-12-01

326

Nuclear Medicine Imaging of Infection in Cancer Patients (With Emphasis on FDG-PET)  

PubMed Central

Infections are a common cause of death and an even more common cause of morbidity in cancer patients. Timely and adequate diagnosis of infection is very important. This article provides clinicians as well as nuclear medicine specialists with a concise summary of the most important and widely available nuclear medicine imaging techniques for infectious and inflammatory diseases in cancer patients with an emphasis on fluorodeoxyglucose positron emission tomography (FDG-PET). 67Ga-citrate has many unfavorable characteristics, and the development of newer radiopharmaceuticals has resulted in the replacement of 67Ga-citrate scintigraphy by scintigraphy with labeled leukocytes or FDG-PET for the majority of conditions. The sensitivity of labeled leukocyte scintigraphy in non-neutropenic cancer patients is comparable with that in patients without malignancy. The specificity, however, is lower because of the uptake of labeled leukocytes in many primary tumors and metastases, most probably as a result of their inflammatory component. In addition, labeled leukocyte scintigraphy cannot be used for febrile neutropenia because of the inability to harvest sufficient peripheral leukocytes for in vitro labeling. FDG-PET has several advantages over these conventional scintigraphic techniques. FDG-PET has shown its usefulness in diagnosing septic thrombophlebitis in cancer patients. It has also been shown that imaging of infectious processes using FDG-PET is possible in patients with severe neutropenia. Although larger prospective studies examining the value of FDG-PET in cancer patients suspected of infection, especially in those with febrile neutropenia, are needed, FDG-PET appears to be the most promising scintigraphic technique for the diagnosis of infection in this patient group.

Vos, Fidel J.; van der Graaf, Winette T.A.; Oyen, Wim J.G.

2011-01-01

327

Vaginal dose, toxicity and sexual outcomes in patients of cervical cancer undergoing image based brachytherapy.  

PubMed

Background: The aim of the study was to evaluate the vaginal dose and toxicity in patients of cervical cancer treated with image guided brachytherapy at our institute. Materials and Methods: Thirty-five patients treated with image based brachytherapy for cervical cancer were included. Vaginal contouring was done on MRI at brachytherapy and with CT scans of subsequent brachytherapy fractions. Dose volume parameters (DVH) were reported in accordance with the GEC-ESTRO guidelines. These were correlated with vaginal toxicity (assessed by CTCAE version 3) and quality of sexual life assessed at one year of completion of treatment. Results: Vaginal shortness was observed in 22 out of 30 (62.8%) patients, Nine (25.7%) had vaginal dryness and in 10 (28.5%) patients, there was contact bleeding. No association could be demonstrated between the dose volume parameters and vaginal toxicity in the present study. Conclusions: The lack of association between dose volume parameters of vagina with vaginal morbidity may be due to uncertainties involved in the delineation of vaginal wall and dosimetry. Future research is required to accurately define vaginal dose distribution to study its correlation with vaginal morbidity. Vaginal morbidity needs to be documented in order to improve the sexual outcome in these patients. PMID:24870767

Rai, Bhavana; Dhanireddy, Bhaswanth; Patel, Firuza Darius; Kumari, Reena; Oinam, Arun Singh; Simha, Vijai; Sharma, Suresh

2014-01-01

328

Tc-99m-diethyl-IDA imaging: clinical evaluation in jaundiced patients  

SciTech Connect

Hepatobiliary imaging with Tc-99m-N,..cap alpha..-(2,6-diethylacetanilide)-iminodiacetic acid (Tc-diethyl-IDA) was performed in 91 jaundiced patients with documented hepatobiliary damage and serum total bilirubin up to 35 mg/dl. There were 56 patients with obstructive jaundice and 35 with hepatocellular disease. Correct discrimination between hepatocellular and obstructive jaundice was possible with an overall accuracy of 90%. Agreement with the final clinical diagnosis was obtained in 97% of patients with hepatocellular disease, and in 86% of patients with obstructive jaundice. The reliability of the test was inversely related to the serum bilirubin levels below 10 mg/dl to 83% for bilirubin between 10 and 20 mg/dl. Above 20 mg/dl, the demonstration of a mechanical obstruction was possible in only one out of the four patients with obstructive jaundice. The high predictive values of the test illustrate that Tc-diethyl-IDA imaging constitutes a reliable method to demonstrate an obstructive cause for the jaundice as long as the bilirubin level remains below 20 mg/dl.

Pauwels, S.; Piret, L.; Schoutens, A.; Vandermoten, G.; Beckers, C.

1980-11-01

329

Quantitative Diffusion Tensor Imaging Tractography Metrics are Associated with Cognitive Performance Among HIV-Infected Patients  

PubMed Central

There have been many studies examining HIV-infection-related alterations of magnetic resonance imaging (MRI) diffusion metrics. However, examining scalar diffusion metrics ignores the orientation aspect of diffusion imaging, which can be captured with tractography. We examined five different tractography metrics obtained from global tractography maps (global tractography FA, average tube length, normalized number of streamtubes, normalized weighted streamtube length, and normalized total number of tubes generated) for differences between HIV positive and negative patients and the association between the metrics and clinical variables of disease severity. We also examined the relationship between these metrics and cognitive performance across a wide range of cognitive domains for the HIV positive and negative patient groups separately. The results demonstrated a significant difference between the groups for global tractography FA (t=2.13, p= 0.04), but not for any of the other tractography metrics examined (p-value range=0.39 to 0.95). There were also several significant associations between the tractography metrics and cognitive performance (i.e., tapping rates, switching 1 and 2, verbal interference, mazes; r?0.42) for HIV infected patients. In particular, associations were noted between tractography metrics, speed of processing, fine motor control/speed, and executive function for the HIV-infected patients. These findings suggest that tractography metrics capture clinically relevant information regarding cognitive performance among HIV infected patients and suggests the importance of subtle white matter changes in examining cognitive performance.

Conley, Jared; Paul, Robert H.; Coop, Kathryn; Zhang, Song; Zhou, Wenjin; Laidlaw, David H.; Taylor, Lynn E.; Flanigan, Timothy; Navia, Bradford; Cohen, Ronald; Tashima, Karen

2010-01-01

330

Quantitative diffusion tensor imaging tractography metrics are associated with cognitive performance among HIV-infected patients.  

PubMed

There have been many studies examining HIV-infection-related alterations of magnetic resonance imaging (MRI) diffusion metrics. However, examining scalar diffusion metrics ignores the orientation aspect of diffusion imaging, which can be captured with tractography. We examined five different tractography metrics obtained from global tractography maps (global tractography FA, average tube length, normalized number of streamtubes, normalized weighted streamtube length, and normalized total number of tubes generated) for differences between HIV positive and negative patients and the association between the metrics and clinical variables of disease severity. We also examined the relationship between these metrics and cognitive performance across a wide range of cognitive domains for the HIV positive and negative patient groups separately. The results demonstrated a significant difference between the groups for global tractography FA (t = 2.13, p = 0.04), but not for any of the other tractography metrics examined (p-value range = 0.39 to 0.95). There were also several significant associations between the tractography metrics and cognitive performance (i.e., tapping rates, switching 1 and 2, verbal interference, mazes; r > or = 0.42) for HIV infected patients. In particular, associations were noted between tractography metrics, speed of processing, fine motor control/speed, and executive function for the HIV-infected patients. These findings suggest that tractography metrics capture clinically relevant information regarding cognitive performance among HIV infected patients and suggests the importance of subtle white matter changes in examining cognitive performance. PMID:20503115

Tate, David F; Conley, Jared; Paul, Robert H; Coop, Kathryn; Zhang, Song; Zhou, Wenjin; Laidlaw, David H; Taylor, Lynn E; Flanigan, Timothy; Navia, Bradford; Cohen, Ronald; Tashima, Karen

2010-03-01

331

Hemodynamic analysis of patients in intensive care unit based on diffuse optical spectroscopic imaging system  

NASA Astrophysics Data System (ADS)

Diffuse optical spectroscopic imaging (DOSI) is a technique to assess the spatial variation in absorption and scattering properties of the biological tissues and provides the monitoring of changes in concentrations of oxy-hemoglobin and deoxy-hemoglobin. In our preliminary study, the temporal tracings of hemodynamic oxygenation are measured with DOSI and venous occlusion test (VOT) from normal subjects, patients with heart failure and patients with sepsis in intensive care unit (ICU). In experiments, the obvious differences of hemodynamic signals can be observed among the three groups. The physiological relevance of VOT hemodynamics with respect to diseases is also discussed in this paper.

Hsieh, Yao-Sheng; Wang, Chun-Yang; Ling, Yo-Wei; Chuang, Ming-Lung; Chuang, Ching-Cheng; Tsai, Jui-Che; Lu, Chih-Wei; Sun, Chia-Wei

2010-02-01

332

Evaluation of cassette performance: physical factors affecting patient exposure and image contrast.  

PubMed

Physical properties of four radiographic cassettes were investigated in combination with various screen/film systems. These properties included (a) transmittance of monoenergetic x rays over 14-96 keV and comparison with predictions based on attenuation coefficients; (b) relative patient exposure from 60 to 120 kV (from phantom measurements) and correlation with predictions based on measured transmittance as well as average energies and angles of incident radiation; and (c) amounts of scatter from various cassette materials and comparison with Monte Carlo calculations. The results provide a model of performance based on quantitation of cassette effects on system speed and image contrast. Carbon-fiber cassettes required the lowest patient exposure, produced the least scatter, and (in low-scatter situations) were capable of increased image contrast. PMID:6828696

Schmidt, R A; Chan, H P; Kodera, Y; Doi, K; Chen, C T

1983-03-01

333

Sites of tuberculous involvement in patients with AIDS. Autopsy findings and evaluation of gallium imaging.  

PubMed

The purpose of this study was to review autopsy and gallium scan findings in two different acquired immune deficiency syndrome (AIDS) patient populations who had a confirmed diagnosis of tuberculosis (TB) to identify organs involved and accuracy of clinical diagnosis. The first group was comprised of 29 autopsies between January 1982 and December 1994, including only 18 patients who were diagnosed before death. Organs most commonly involved were the lymph nodes (59%), lungs (56%), spleen (53%), liver (45%), and kidneys (37%). Other opportunistic infections were present in 18 (59%) of autopsies, with more than one opportunistic infection present in 11 (37%) of the autopsies. Lungs were involved in 79% of all autopsies. The second population group included 94 patients with AIDS with a proven diagnosis of TB, only 24 of whom had gallium scans in the period between January 1992 and December 1994. Chest x-ray results were negative in 4 patients (17%); gallium scan results were positive in 16 patients (66%). The reasons for false-negative gallium scan results were due to anti-tuberculous treatment for periods varying from 2-21 months in 7 patients or the presence of extra pulmonary tuberculosis. The sites of TB involvement in the chest were: lung parenchyma in 5 patients (19%, 4 in mid and lower lung, and 1 in upper fields). There was lymph node involvement in all 16 patients (24 locations with mediastinal involvement in 23%, supraclavicular 23%, axillary 11%, retroperitoneal 11%, and inguinal region in 4%. We conclude that (1) tuberculosis in patients with AIDS behaves similar to primary tuberculosis; (2) the combination of chest x-ray and gallium imaging is sensitive for the diagnosis of pulmonary tuberculosis in patients with AIDS; (3) the involvement of mediastinal lymph nodes in gallium scans in the presence or absence of chest x-ray abnormalities should raise the possibility of TB involvement in patients with human immunodeficiency virus; (4) anti-TB treatment decreases the sensitivity of gallium scan. PMID:9152531

Abdel-Dayem, H M; Naddaf, S; Aziz, M; Mina, B; Turoglu, T; Akisik, M F; Omar, W S; DiFabrizio, L; LaBombardi, V; Kempf, J S

1997-05-01

334

Clinical safety of magnetic resonance imaging in patients with implanted SynchroMed EL infusion pumps  

Microsoft Academic Search

Introduction  Patients with implanted SynchroMed spinal infusion pumps (Medtronic, Inc., Minneapolis, MN) routinely undergo magnetic resonance\\u000a imaging at our institution. In August 2008, Medtronic issued an urgent medical device correction report regarding several\\u000a pumps. Because of the rare potential “for a delay in the return of proper drug infusion” and “for a delay in the logging of\\u000a motor stall events,” “a

Felix E. Diehn; Christopher P. Wood; Robert E. Watson Jr; William D. Mauck; Michelle M. Burke; Christopher H. Hunt

2011-01-01

335

A protocol for the reduction of systematic patient setup errors with minimal portal imaging workload  

Microsoft Academic Search

Purpose: To evaluate a new off-line patient setup correction protocol that minimizes the required number of portal images and perform a comparison with currently applied protocols.Methods and Materials: We compared two types of off-line protocols: (a) the widely applied shrinking action level (SAL) protocol, in which the setup error, averaged over the measured treatment fractions, is compared with a threshold

Hans C. J. de Boer; Ben J. M. Heijmen

2001-01-01

336

Cerebral Aneurysms: A Patient-Specific and Image-Based Management Pipeline  

Microsoft Academic Search

\\u000a This work presents an image- and biomechanics-based data processing pipeline able to build patient-specific models of cerebral\\u000a aneurysms. The pipeline also contemplates the virtual modeling and release of endovascular devices such as stents and coils.\\u000a As a result of the morphological, morphodynamic, hemodynamic and structural analyses, a set of complex descriptors relevant\\u000a for aneurysm’s diagnosis and prognosis is derived. On

M. C. Villa-Uriol; I. Larrabide; J. M. Pozo; M. Kim; M. Craene; O. Camara; C. Zhang; A. J. Geers; H. Bogunovi?; H. Morales; A. F. Frangi

337

Robust spectral analysis of videocapsule images acquired from celiac disease patients  

PubMed Central

Background Dominant frequency (DF) analysis of videocapsule endoscopy images is a new method to detect small intestinal periodicities that may result from mechanical rhythms such as peristalsis. Longer periodicity is related to greater image texture at areas of villous atrophy in celiac disease. However, extraneous features and spatiotemporal phase shift may mask DF rhythms. Method The robustness of Fourier and ensemble averaging spectral analysis to compute DF was tested. Videocapsule images from the distal duodenum of 11 celiac patients (frame rate 2/s and pixel resolution 576 × 576) were analyzed. For patients 1, 2, ... 11, respectively, a total of 10, 11, ..., 20 sequential images were extracted from a randomly selected time epoch. Each image sequence was artificially repeated to 200 frames, simulating periodicities of 0.2, 0.18, ..., 0.1Hz, respectively. Random white noise at four different levels, spatiotemporal phase shift, and frames with air bubbles were added. Power spectra were constructed pixel-wise over 200 frames, and an average spectrum was computed from the 576 × 576 individual spectra. The largest spectral peak in the average spectrum was the estimated DF. Error was defined as the absolute difference between actual DF and estimated DF. Results For Fourier analysis, the mean absolute error between estimated and actual DF was 0.032 ± 0.052Hz. Error increased with greater degree of random noise imposed. In contrast, all ensemble average estimates precisely predicted the simulated DF. Conclusions The ensemble average DF estimate of videocapsule images with simulated periodicity is robust to noise and spatiotemporal phase shift as compared with Fourier analysis. Accurate estimation of DF eliminates the need to impose complex masking, extraction, and/or corrective preprocessing measures.

2011-01-01

338

HIPAA, dermatology images, and the law.  

PubMed

From smart phones to iPads, the world has grown increasingly reliant on new technology. In this ever-expanding digital age, medicine is at the forefront of these new technologies. In the field of dermatology and general medicine, digital images have become an important tool used in patient management. Today, one can even find physicians who use their cellular phone cameras to take patient images and transmit them to other physicians. However, as digital imaging technology has become more prevalent so too have concerns about the impact of this technology on the electronic medical record, quality of patient care, and medicolegal issues. This article will discuss the advent of digital imaging technology in dermatology and the legal ramifications digital images have on medical care, abiding by HIPAA, the use of digital images as evidence, and the possible abuses digital images can pose in a health care setting. PMID:24800426

Scheinfeld, Noah; Rothstein, Brooke

2013-12-01

339

Tissue Doppler imaging and tissue strain imaging for the evaluation of hepatic fibrosis in patients with chronic hepatitis B.  

PubMed

We studied the feasibility of evaluating the stages of liver fibrosis with tissue Doppler imaging (TDI) and tissue strain imaging (TSI) for patients with chronic hepatitis B virus infection. One hundred ten patients were divided into two groups: normal adult group (n = 38) and chronic liver disease group (n = 72, patients infected with HBVs). The chronic liver disease group was divided into three subgroups on the basis of the Scheuer scoring system and clinical evidence: mild fibrosis (S0 and S1, n = 11), moderate fibrosis (S2 and S3, n = 27) and cirrhosis (S4 and clinically typical cirrhosis, n = 34) groups. TDI was performed for a chosen oblique section. Four regions of interest (ROIs), A-D, were chosen in the hepatic parenchyma based on the direction of propagation from the heart to the liver. Strain rate curves were obtained on the basis of TDI and TSI findings. Strain peak rates (SPRs) of all ROIs and the differences in times to SPRs for the four ROIs (TA-B, TB-C and TC-D) in the hepatic parenchyma were measured with TDI and TSI. Strain rate curves were analyzed for each ROI. The strain rate curves for the normal adult group were synchronous, whereas those for the chronic liver disease group were asynchronous. SPRs of the ROIs gradually decreased with the progression of liver fibrosis. The SPRs of ROI B significantly correlated with chronic liver disease severity (r = 0.991, p < 0.05). Areas under the curve (AUCs) of the ROI A and ROI B SPRs at the moderate fibrosis and cirrhosis stages were 0.86 ± 0.06, 0.81 ± 0.56 and 0.90 ± 0.65, 0.92 ± 0.04, respectively. The AUC of the SPRs of ROIs A and B correlated better than the platelet/age/phosphatase/?-fetoprotein/aspartate aminotransferase (PAPAS) index for advanced fibrosis. The differences in time to SPRs among the peaks of the four ROIs (TA-B, TB-C and TC-D) gradually increased with the progression of liver fibrosis. TDI and TSI with quantitative measurements using tissue Doppler analysis software (TDIQ, GE Medical Systems, Horten, Norway) provided reliable information for evaluating non-invasive liver fibrosis in patients with chronic hepatitis B. PMID:23791352

Wang, Ying; Wu, Zhifeng; Ju, Yan; Cao, Li; Shi, Lin; Tong, Fa; Jiang, Xuan; Zhu, Changren

2013-09-01

340

Clinical Application of Magnetic Resonance Imaging in Management of Breast Cancer Patients Receiving Neoadjuvant Chemotherapy  

PubMed Central

Neoadjuvant chemotherapy (NAC), also termed primary, induction, or preoperative chemotherapy, is traditionally used to downstage inoperable breast cancer. In recent years it has been increasingly used for patients who have operable cancers in order to facilitate breast-conserving surgery, achieve better cosmetic outcome, and improve prognosis by reaching pathologic complete response (pCR). Many studies have demonstrated that magnetic resonance imaging (MRI) can assess residual tumor size after NAC, and that provides critical information for planning of the optimal surgery. NAC also allows for timely adjustment of administered drugs based on response, so ineffective regimens could be terminated early to spare patients from unnecessary toxicity while allowing other effective regimens to work sooner. This review article summarizes the clinical application of MRI during NAC. The use of different MR imaging methods, including dynamic contrast-enhanced MRI, proton MR spectroscopy, and diffusion-weighted MRI, to monitor and evaluate the NAC response, as well as how changes of parameters measured at an early time after initiation of a drug regimen can predict final treatment outcome, are reviewed. MRI has been proven a valuable tool and will continue to provide important information facilitating individualized image-guided treatment and personalized management for breast cancer patients undergoing NAC.

Chen, Jeon-Hor

2013-01-01

341

Hybrid SPECT/CT Imaging in the Evaluation of Coronary Stenosis: Role in Diabetic Patients  

PubMed Central

Purpose. Our purpose was to combine the results of the MDCT (multidetector computed tomography) morphological data and the SPECT (single-photon emission computed tomography) data using hybrid imaging to overcome the limits of the MDCT in the evaluation of coronary stenosis in diabetic patients with large amount of calcium in the coronary arteries. Method and Materials. 120 diabetic patients underwent MDCT examination and SPECT examination. We evaluated 324 coronary arteries. After the examinations, we merged CT and SPECT images. Results. CT evaluation: 52 (32.8%) coronaries with stenosis ? 50%, 228 (70.4%) with stenosis < 50%, and 44 (13.6%) with a doubtful evaluation. SPECT evaluation: 80 (24.7%) areas with hypoperfusion, 232 (71.6%) with normal perfusion, and 12 (3.7%) with a doubtful evaluation. Of 324 coronary arteries and corresponding areas, the hybrid SPECT/CT evaluation showed 92 (28.4%) areas with hypoperfusion, and 232 (71.6%) with normal perfusion. Conclusion. Hybrid CT/SPECT imaging could be useful in the detection of significant coronary stenosis in patients with large amount of coronary calcifications.

Romagnoli, Andrea; Schillaci, Orazio; Arganini, Chiara; Gaspari, Eleonora; Ricci, Aurora; Morosetti, Daniele; Coco, Irene; Crusco, Sonia; Calabria, Ferdinando; Sperandio, Massimiliano; Simonetti, Giovanni

2013-01-01

342

High Total Hospitalization Cost but Low Cost of Imaging Studies in Recurrent Acute Ischemic Stroke Patients  

PubMed Central

Background Due to the high risk and severity of recurrence after stroke attack, recurrence is a major reason contributing to the disease burden. This study aims to determine whether recurrence is a significant contributor of hospitalization cost in items for ischemic stroke patients. Methods This study assessed acute ischemic stroke patients admitted to an academic medical center in 2003 through 2009. The t-test and Chi-square tests were used to compare first-ever and recurrent ischemic stroke groups in terms of total and categorized hospitalization cost, and multiple regression was performed to assess the influence of stroke recurrence. Results Recurrent ischemic strokes were associated with higher total cost, but examination cost showed no difference between the two groups. The recurrent stroke group showed higher laboratory but lower imaging cost. Of imaging studies, there was no significant difference in computed tomography scan cost while the first-ever stroke group spent more on magnetic resonance imaging and sonography. Controlling for other influential factors, recurrence was discovered to be a significant factor in lowering examination cost. Conclusions The findings of stroke recurrence in lowering examination cost could be explained from two perspectives, different clinical patterns of healthcare utilization and patients' economic status in recurrent stroke.

Kwon, Young Dae; Yoon, Sung Sang; Chang, Hyejung

2014-01-01

343

Application of image analysis in the myocardial biopsies of patients with dilated cardiomyopathy  

NASA Astrophysics Data System (ADS)

The aim of our study is to investigate if myocardial fibrosis measured by image analysis may be considered as an important and accurate index of dilated cardiomyopathy and its prognosis. The study group consisted of 24 patients with dilated cardiomyopathy which was diagnosed by echocardiography, radionuclide ventriculography, cardiac catheterization and left ventricular endomyocardial biopsy. The patients' overall disability was conventionally expressed with the criteria for functional capacity. Using image analysis the percentage of fibrosis in a total of 35 myocardial biopsies was measured accurately. A comparison study between the percentage of myocardial fibrosis and the clinical parameters (left ventricular ejection fraction and overall functional capacity) showing the degree of each patient's heart failure followed. A correlation was found among fibrosis, left ventricular ejection fraction and overall functional capacity. The cases with small values of fibrosis (less than 10%) have big values of ejection fraction and belong in Class I of overall functional capacity. The cases with big values of fibrosis (greater than 10%) belong in Classes III and IV of overall functional capacity and have small values of ejection fraction. The results of the comparison study were presented graphically and were considered significant. Myocardial fibrosis measured by image analysis might be considered an important prognostic index of dilated cardiomyopathy.

Agapitos, Emanuel; Kavantzas, Nikolaos; Bakouris, M. G.; Kassis, Kyriakos A.; Nanas, J.; Margari, Z.; Davaris, P.

1996-04-01

344

Imaging plaques to predict and better manage patients with acute coronary events.  

PubMed

Culprit lesions of patients, who have had an acute coronary syndrome commonly, are ruptured coronary plaques with superimposed thrombus. The precursor of such lesions is an inflamed thin-capped fibroatheroma. These plaques can be imaged by means of invasive techniques, such as intravascular ultrasound (and derived techniques), optical coherence tomography, and near-infrared spectroscopy. Often these patients exhibit similar (multiple) plaques beyond the culprit lesion. These remote plaques can be assessed noninvasively by computed tomographic angiography and MRI and also using invasive imaging. The detection of these remote plaques is not only feasible but also in natural history studies have been associated with clinical coronary events. Different systemic pharmacological treatments have been studied (mostly statins) with modest success and, therefore, newer approaches are being tested. Local treatment for such lesions is in its infancy and larger, prospective, and randomized trials are needed. This review will describe the pathological and imaging findings in culprit lesions of patients with acute coronary syndrome and the assessment of remote plaques. In addition, the pharmacological and local treatment options will be reviewed. PMID:24902974

Garcia-Garcia, Hector M; Jang, Ik-Kyung; Serruys, Patrick W; Kovacic, Jason C; Narula, Jagat; Fayad, Zahi A

2014-06-01

345

Vasodilator Stress Perfusion CMR Imaging Is Feasible and Prognostic in Obese Patients  

PubMed Central

Objectives This study sought to determine feasibility and prognostic performance of stress cardiac magnetic resonance (CMR) in obese patients (body mass index [BMI] ?30 kg/m2). Background Current stress imaging methods remain limited in obese patients. Given the impact of the obesity epidemic on cardiovascular disease, alternative methods to effectively risk stratify obese patients are needed. Methods Consecutive patients with a BMI ?30 kg/m2 referred for vasodilating stress CMR were followed for major adverse cardiovascular events (MACE), defined as cardiac death or nonfatal myocardial infarction. Univariable and multivariable Cox regressions for MACE were performed to determine the prognostic association of inducible ischemia or late gadolinium enhancement (LGE) by CMR beyond traditional clinical risk indexes. Results Of 285 obese patients, 272 (95%) completed the CMR protocol, and among these, 255 (94%) achieved diagnostic imaging quality. Mean BMI was 35.4 ± 4.8 kg/m2, with a maximum weight of 200 kg. Reasons for failure to complete CMR included claustrophobia (n = 4), intolerance to stress agent (n = 4), poor gating (n = 4), and declining participation (n = 1). Sedation was required in 19 patients (7%; 2 patients with intravenous sedation). Sixteen patients required scanning by a 70-cm-bore system (6%). Patients without inducible ischemia or LGE experienced a substantially lower annual rate of MACE (0.3% vs. 6.3% for those with ischemia and 6.7% for those with ischemia and LGE). Median follow-up of the cohort was 2.1 years. In a multivariable stepwise Cox regression including clinical characteristics and CMR indexes, inducible ischemia (hazard ratio 7.5; 95% confidence interval: 2.0 to 28.0; p = 0.002) remained independently associated with MACE. When patients with early coronary revascularization (within 90 days of CMR) were censored on the day of revascularization, both presence of inducible ischemia and ischemia extent per segment maintained a strong association with MACE. Conclusions Stress CMR is feasible and effective in prognosticating obese patients, with a very low negative event rate in patients without ischemia or infarction.

Shah, Ravi V.; Heydari, Bobak; Coelho-Filho, Otavio; Abbasi, Siddique A.; Feng, Jiazhuo H.; Neilan, Tomas G.; Francis, Sanjeev; Blankstein, Ron; Steigner, Michael; Jerosch-Herold, Michael; Kwong, Raymond Y.

2014-01-01

346

Characterization of the calcaneal fat pad in diabetic and non-diabetic patients using magnetic resonance imaging  

Microsoft Academic Search

It is well known that diabetic patients have a high incidence of foot ulceration. The purpose of this study was to determine whether magnetic resonance (MR) imaging can detect changes in the composition of the calcaneal fat pad in diabetic feet. MR data were collected in vitro from amputated specimens (eight from diabetic patients and eight from non-diabetic patients) as

Patricia F Kao; Brian L Davis; Peter A Hardy

1999-01-01

347

An adaptive patient specific deformable registration for breast images of positron emission tomography and magnetic resonance imaging using finite element approach  

NASA Astrophysics Data System (ADS)

A patient specific registration model based on finite element method was investigated in this study. Image registration of Positron Emission Tomography (PET) and Magnetic Resonance imaging (MRI) has been studied a lot. Surface-based registration is extensively applied in medical imaging. We develop and evaluate a registration method combine surface-based registration with biomechanical modeling. .Four sample cases of patients with PET and MRI breast scans performed within 30 days were collected from hospital. K-means clustering algorithm was used to segment images into two parts, which is fat tissue and neoplasm [2]. Instead of placing extrinsic landmarks on patients' body which may be invasive, we proposed a new boundary condition to simulate breast deformation during two screening. Then a three dimensional model with meshes was built. Material properties were assigned to this model according to previous studies. The whole registration was based on a biomechanical finite element model, which could simulate deformation of breast under pressure.

Xue, Cheng; Tang, Fuk-Hay

2014-03-01

348

Assessment of abnormal systolic intraventricular flow patterns by Doppler imaging in patients with left ventricular dyssynergy.  

PubMed

Few data exist regarding the consequences of abnormalities of segmental contraction on intraventricular flow patterns. The development of color Doppler flow imaging has now permitted the visualization of intraventricular blood flow patterns. Therefore, we performed Doppler flow mapping in 41 patients (12 with normal left ventricular contraction, eight with hypokinesis or akinesis, and 21 with dyskinesis) and compared these findings with left ventriculography. Systolic blood flow by Doppler mapping in subjects with normal ventricular contraction was characterized primarily by flow through the left ventricular outflow tract and into the aorta. In patients with dyskinesis, paradoxical systolic flow toward the abnormal segment was present, and persisted for at least 50% of systole in 18 of 21 patients. Mean duration of paradoxical flow in dyskinetic patients was 77% of systole. Paradoxical flow was also observed in two of five patients with akinesis but in no patients with hypokinesis. A good correlation was observed between the duration of paradoxical systolic flow and indexes of regional wall motion (radian shortening of the involved myocardium) (r = 0.77) and global ejection fraction derived from cineangiography (r = 0.79). Correlations between the area of the paradoxical systolic flow stream in midsystole and indexes of left ventricular function were less close, with r equaling 0.57 for both regional wall motion and ejection fraction. Thus, paradoxical systolic flow can be detected in most patients with left ventricular dyskinesis, and correlates with the magnitude of regional and global left ventricular dysfunction by cineangiography. PMID:2364529

Garrahy, P J; Kwan, O L; Booth, D C; DeMaria, A N

1990-07-01

349

A phantom evaluation of a stereo-vision surface imaging system for radiotherapy patient setup  

SciTech Connect

External beam irradiation requires precise positioning of the target relative to the treatment planning coordinate system. A three-dimensional (3D) surface imaging system for patient positioning has recently been installed in one of our linear accelerator (linac) rooms. The device utilizes close-range photogrammetry to generate a 3D model of the patient's surface. This geometric model can be made to look like a digital camera image if wrapped with a gray-level image (texture mapping) that shows surface coloration. The system is calibrated to the linac coordinate system and has been designed as a patient setup device. To reproduce patient position in fractionated radiotherapy, the daily patient surface model is registered to a previously recorded reference surface. Using surface registration, the system calculates the rigid-body transformation that minimizes the distance between the treatment and the reference surface models in a region-of-interest (ROI). This transformation is expressed as a set of new couch coordinates at which the patient position best matches with the reference data. If respiratory motion is a concern, the surface can be obtained with a gated acquisition at a specified phase of the respiratory cycle. To analyze the accuracy of the system, we performed several experiments with phantoms to assess stability, alignment accuracy, precision of the gating function, and surface topology. The reproducibility of surface measurements was tested for periods up to 57 h. Each recorded frame was registered to the reference surface to calculate the required couch adjustment. The system stability over this time period was better than 0.5 mm. To measure the accuracy of the system to detect and quantify patient shift relative to a reference image, we compared the shift detected by the surface imaging system with known couch transitions in a phantom study. The maximum standard deviation was 0.75 mm for the three translational degrees of freedom, and less than 0.1 deg. for each rotation. Surface model precision was tested against computed tomography (CT)-derived surface topology. The root-mean-square rms of the distance between the surfaces was 0.65 mm, excluding regions where beam hardening caused artifacts in the CT data. Measurements were made to test the gated acquisition mode. The time-dependent amplitude was measured with the surface imaging system and an established respiratory gating system based on infrared (IR)-marker detection. The measured motion trajectories from both systems were compared to the known trajectory of the stage. The standard deviations of the amplitude differences to the motor trajectory were 0.04 and 0.15 mm for the IR-marker system and the 3D surface imaging system, respectively. A limitation of the surface-imaging device is the frame rate of 6.5 Hz, because rapid changes of the motion trajectory cannot be detected. In conclusion, the system is accurate and sufficiently stable to be used in the clinic. The errors computed when comparing the surface model with CT geometry were submillimeter, and deviations in the alignment and gating-signal tests were of the same magnitude.

Bert, Christoph; Metheany, Katherine G.; Doppke, Karen; Chen, George T.Y. [Biophysics, Gesellschaft fuer Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)

2005-09-15

350

Diffusion-weighted MR imaging with single-shot echo-planar imaging in the upper abdomen: preliminary clinical experience in 61 patients  

Microsoft Academic Search

Background: To determine the potential ability of diffusion-weighted magnetic resonance (MR) imaging with single-shot echo-planar imaging\\u000a (DW imaging) in the upper abdomen by apparent diffusion coefficient (ADC) and signal:intensity ratio (SIR) measurements.\\u000a \\u000a \\u000a \\u000a \\u000a Methods: DW imaging was performed in 61 clinical patients. ADCs in the liver, pancreas, spleen, kidney, and different pathological\\u000a conditions were calculated. Spleen-to-liver SIR and segmental intensity difference

T. Ichikawa; H. Haradome; J. Hachiya; T. Nitatori; T. Araki

1999-01-01

351

Imaging Lymphatic System in Breast Cancer Patients with Magnetic Resonance Lymphangiography  

PubMed Central

Objective To investigate the feasibility of gadolinium (Gd) contrast-enhanced magnetic resonance lymphangiography (MRL) in breast cancer patients within a typical clinical setting, and to establish a Gd-MRL protocol and identify potential MRL biomarkers for differentiating metastatic from non-metastatic lymph nodes. Materials and Methods 32 patients with unilateral breast cancer were enrolled and divided into 4 groups of 8 patients. Groups I, II, and III received 1.0, 0.5, and 0.3 ml of intradermal contrast; group IV received two 0.5 ml doses of intradermal contrast. MRL images were acquired on a 3.0 T system and evaluated independently by two radiologists for the number and size of enhancing lymph nodes, lymph node contrast uptake kinetics, lymph vessel size, and contrast enhancement patterns within lymph nodes. Results Group III patients had a statistically significant decrease in the total number of enhancing axillary lymph nodes and lymphatic vessels compared to all other groups. While group IV patients had a statistically significant faster time to reach the maximum peak enhancement over group I and II (by 3 minutes), there was no other statistically significant difference between imaging results between groups I, II, and IV. 27 out of 128 lymphatic vessels (21%) showed dilatation, and all patients with dilated lymphatic vessels were pathologically proven to have metastases. Using the pattern of enhancement defects as the sole criterion for identifying metastatic lymph nodes during Gd-MRL interpretation, and using histopathology as the gold standard, the sensitivity and specificity were estimated to be 86% and 95%, respectively. Conclusion Gd-MRL can adequately depict the lymphatic system, can define sentinel lymph nodes, and has the potential to differentiate between metastatic and non-metastatic lymph nodes in breast cancer patients.

Lu, Qing; Hua, Jia; Kassir, Mohammad M.; Delproposto, Zachary; Dai, Yongming; Sun, Jingyi; Haacke, Mark; Hu, Jiani

2013-01-01

352

Diffusion-weighted imaging in noncompressive myelopathies: a 33-patient prospective study.  

PubMed

Diffusion-weighted imaging (DWI) is frequently used to differentiate cerebral lesions. The aim of our study was to evaluate the diagnostic value of DWI and the measurement of the apparent diffusion coefficient (ADC) in noncompressive myelopathy explorations. Thirty-three patients presenting a spinal cord syndrome due to a noncompressive myelopathy underwent spinal cord MRI between September 2005 and November 2008. For each patient, the ADC was calculated in the pathological spinal cord. ADC values were also measured in the healthy spinal cord of ten control subjects. Statistical analysis was based on the Student's t test. Twenty-one patients presented an inflammatory myelopathy: Nine patients presented multiple sclerosis, three patients presented a parainfectious myelopathy, two patients acute disseminated encephalomyelitis, one patient neuromyelitis optica, one patient systemic lupus erythematosus, and five patients a myelopathy of unknown aetiology. Six patients presented a spinal cord infarction. ADC values were significantly lower in spinal cord infarct (mean ADC = 0.81 +/- 0.08 x 10(-3) mm(2)/s) than in inflammatory spinal cord lesions (mean ADC = 1.37 +/- 0.23 x 10(-3) mm(2)/s) and in healthy control spinal cord (mean ADC = 0.93 +/- 0.07 x 10(-3) mm(2)/s). These results are important to differentiate ischaemic from inflammatory myelopathies, especially at the acute phase when clinical presentation and extensive work-up are not able to show an aetiologic diagnosis. Although these results are similar to those described in cerebral explorations, ADC measurements remain technically limited for the moment. PMID:20425119

Marcel, Christophe; Kremer, Stéphane; Jeantroux, Jérémy; Blanc, Frédéric; Dietemann, Jean-Louis; De Sèze, Jérôme

2010-09-01

353

Differentiated thyroid cancer: a new perspective with radiolabeled somatostatin analogues for imaging and treatment of patients.  

PubMed

Background: The expression of somatostatin receptors (SSTR) in thyroid cells may offer the possibility to identify metastatic lesions and to select patients for peptide receptor radionuclide therapy (PRRT). We investigated (68)Ga-DOTATOC positron emission tomography/computed tomography (PET/CT) to select patients with progressive differentiated thyroid cancer (DTC) for PRRT as well as treatment response and toxicity in treated patients. Methods: We enrolled 41 patients with progressive radioiodine-negative DTC (24 women and 17 men; mean age=54.3 years, median=59 years, range=19-78 years). In all patients, [(18)F]FDG-PET/CT was performed to determine recurrent disease with enhanced glucose metabolism, and (68)Ga-DOTATOC PET/CT was used to identify SSTR expression. Dosimetric evaluation was performed with (111)In-DOTATOC scintigraphy. Eleven patients were treated with PRRT receiving a fractionated injection of 1.5-3.7 GBq (90)Y-DOTATOC/administration. Serial (68)Ga-DOTATOC PET/CT scans were performed in all treated patients to evaluate treatment response. Parameters provided by (68)Ga-DOTATOC PET/CT were analyzed as potential therapeutic predictors to differentiate responding from nonresponding. In all treated patients, adverse events and toxicity were recorded. Results: (68)Ga-DOTATOC PET/CT were positive in 24/41 of radioiodine-negative DTC patients. Based on the high expression of SSTR detected by (68)Ga-DOTATOC PET/CT, 13 patients were suitable for PRRT. Two out of 13 patients were not treated due to the lack of fulfillment of other study inclusion criteria. PRRT induced disease control in 7/11 patients (two partial response and five stabilization) with a duration of response of 3.5-11.5 months. Objective response was associated with symptoms relief. Functional volume (FV) over time obtained by PET/CT was the only parameter demonstrating a significant difference between lesions responding and nonresponding to PRRT (p=0.001). Main PRRT adverse events were nausea, asthenia, and transient hematologic toxicity. One patient experienced permanent renal toxicity. Conclusions: In our series, SSTR imaging provided positive results in more than half of the cases with radioiodine-negative DTC, and about one third of patients were eligible for PRRT. (68)Ga-DOTATOC PET/CT seems a reliable tool both for patient selection and evaluation of treatment response. In our experience, FV determination over time seems to represent a reliable parameter to determine tumor response to PRRT, although further investigations are needed to better define its role. PMID:24102584

Versari, Annibale; Sollini, Martina; Frasoldati, Andrea; Fraternali, Alessandro; Filice, Angelina; Froio, Armando; Asti, Mattia; Fioroni, Federica; Cremonini, Nadia; Putzer, Daniel; Erba, Paola Anna

2014-04-01

354

Images created in a model eye during simulated cataract surgery can be the basis for images perceived by patients during cataract surgery.  

PubMed

PurposeTo evaluate the images created in a model eye during simulated cataract surgery.Patients and methodsThis study was conducted as a laboratory investigation and interventional case series. An artificial opaque lens, a clear intraocular lens (IOL), or an irrigation/aspiration (I/A) tip was inserted into the 'anterior chamber' of a model eye with the frosted posterior surface corresponding to the retina. Video images were recorded of the posterior surface of the model eye from the rear during simulated cataract surgery. The video clips were shown to 20 patients before cataract surgery, and the similarity of their visual perceptions to these images was evaluated postoperatively.ResultsThe images of the moving lens fragments and I/A tip and the insertion of the IOL were seen from the rear. The image through the opaque lens and the IOL without moving objects was the light of the surgical microscope from the rear. However, when the microscope light was turned off after IOL insertion, the images of the microscope and operating room were observed by the room illumination from the rear. Seventy percent of the patients answered that the visual perceptions of moving lens fragments were similar to the video clips and 55% reported similarity with the IOL insertion. Eighty percent of the patients recommended that patients watch the video clip before their scheduled cataract surgery.ConclusionsThe patients' visual perceptions during cataract surgery can be reproduced in the model eye. Watching the video images preoperatively may help relax the patients during surgery. PMID:24788007

Inoue, M; Uchida, A; Shinoda, K; Taira, Y; Noda, T; Ohnuma, K; Bissen-Miyajima, H; Hirakata, A

2014-07-01

355

Using imaging to guide patient selection and performance of catheter-based mitral valve repair for mitral regurgitation.  

PubMed

Percutaneous transcatheter therapies for mitral regurgitation have found a role for patients at high operative risk with both degenerative and functional pathologies. The MitraClip therapy utilizes a catheter-based system to deliver a clip-type implant to provide apposition between anterior and posterior mitral leaflets. Key to the procedure is using imaging to guide patient selection as well as intra-procedure performance. Careful patient selection remains paramount for success with the MitraClip, with imaging determination of appropriate mitral pathology. Technical success is dependent on skill with echocardiographic imaging, with three-dimensional transesophageal echocardiography particularly valuable. PMID:24057275

Lim, D Scott

2013-10-01

356

Prostate Cancer: Can Multiparametric MR Imaging Help Identify Patients Who Are Candidates for Active Surveillance?  

PubMed Central

Purpose: To determine whether multiparametric magnetic resonance (MR) imaging can help identify patients with prostate cancer who would most appropriately be candidates for active surveillance (AS) according to current guidelines and to compare the results with those of conventional clinical assessment scoring systems, including the D’Amico, Epstein, and Cancer of the Prostate Risk Assessment (CAPRA) systems, on the basis of findings at prostatectomy. Materials and Methods: This institutional review board–approved HIPAA-compliant retrospectively designed study included 133 patients (mean age, 59.3 years) with a mean prostate-specific antigen level of 6.73 ng/mL (median, 4.39 ng/mL) who underwent multiparametric MR imaging at 3.0 T before radical prostatectomy. Informed consent was obtained from all patients. Patients were then retrospectively classified as to whether they would have met AS eligibility criteria or were better served by surgery. AS eligibility criteria for prostatectomy specimens were a dominant tumor smaller than 0.5 mL without Gleason 4 or 5 patterns or extracapsular or seminal vesicle invasion. Conventional clinical assessment scores (the D’Amico, Epstein, and CAPRA scoring systems) were compared with multiparametric MR imaging findings for predicting AS candidates. The level of significance of difference between scoring systems was determined by using the ?2 test for categoric variables with the level of significance set at P < .05. Results: Among 133 patients, 14 were eligible for AS on the basis of prostatectomy results. The sensitivity, positive predictive value (PPV), and overall accuracy, respectively, were 93%, 25%, and 70% for the D’Amico system, 64%, 45%, and 88% for the Epstein criteria, and 93%, 20%, and 59% for the CAPRA scoring system for predicting AS candidates (P < .005 for all, ?2 test), while multiparametric MR imaging had a sensitivity of 93%, a PPV of 57%, and an overall accuracy of 92% (P < .005). Conclusion: Multiparametric MR imaging provides useful additional information to existing clinicopathologic scoring systems of prostate cancer and improves the assignment of treatment (eg, AS or active treatment). © RSNA, 2013 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121325/-/DC1

Turkbey, Baris; Mani, Haresh; Aras, Omer; Ho, Jennifer; Hoang, Anthony; Rastinehad, Ardeshir R.; Agarwal, Harsh; Shah, Vijay; Bernardo, Marcelino; Pang, Yuxi; Daar, Dagane; McKinney, Yolanda L.; Linehan, W. Marston; Kaushal, Aradhana; Merino, Maria J.; Wood, Bradford J.; Pinto, Peter A.

2013-01-01

357

Myocardial extracellular volume by cardiac magnetic resonance imaging in patients treated with anthracycline-based chemotherapy.  

PubMed

We aimed to determine whether the myocardial extracellular volume (ECV), measured using T1 measurements obtained during cardiac magnetic resonance imaging were increased in patients treated with anthracyclines. We performed cardiac magnetic resonance imaging and echocardiography and measured the ECV in 42 patients treated with anthracyclines. The data from the cardiac magnetic resonance study were compared to those from healthy volunteers. The anthracycline-treated cohort consisted of 21 men and 21 women with a mean age of 55 ± 17 years, who presented a median of 84 months after chemotherapy with a cumulative anthracycline exposure of 282 ± 65 mg/m(2) and a mean left ventricular ejection fraction of 52 ± 12%. The ECV was elevated in the anthracycline-treated patients compared to the age- and gender-matched controls (0.36 ± 0.03 vs 0.28 ± 0.02, p <0.001). A positive association was found between the ECV and left atrial volume (ECV vs indexed left atrial volume, r = 0.65, p <0.001), and negative association was found between the ECV and diastolic function (E' lateral, r = -0.64, p <0.001). In conclusion, the myocardial ECV is elevated in patients with previous anthracycline treatment and is associated with the diastolic function and increased atrial volumes. PMID:23228924

Neilan, Tomas G; Coelho-Filho, Otavio R; Shah, Ravi V; Feng, Jiazuo H; Pena-Herrera, Diego; Mandry, Damien; Pierre-Mongeon, Francois; Heydari, Bobak; Francis, Sanjeev A; Moslehi, Javid; Kwong, Raymond Y; Jerosch-Herold, Michael

2013-03-01

358

Morphological and functional imaging in neurological and non-neurological Wilson's patients.  

PubMed

Wilson's disease causes disturbances of the central nervous system, affecting it both directly through copper toxicity and indirectly subject to a copper-induced hepatopathy, resulting in morphological and physiological changes in brain structures that can be captured by means of magnetic resonance imaging (MRI), (123) I-?-CIT (2?-carbomethoxy-3? (4-iodophenyl)tropane)-SPECT (single photon emission computed tomography), (123) I-IBZM (benzamide)-SPECT and [(18) F]FDG -PET (fluorodeoxyglucose-positron emission tomography). MRI can reveal even slight morphological changes in non-neurological Wilson's patients. More marked findings in neurological Wilson's patients become evident in T1- and T2-weighted MRI. T1-weighted MRI predominantly detects atrophic changes, whereas T2-weighted MRI regularly records signal changes in the putamen. With the aid of these three nuclear-medicine examinations, nigrostriatal and metabolic disturbances are identified in neurological Wilson's patients only. Sufficient decoppering therapy prevents progression and even tends to improve symptoms. A correlation between any of the imaging findings in patients with the genetic phenotype and the incidence of the most common mutation H1069Q (homozygote or compound heterozygote) or other mutations could not be substantiated. PMID:24495036

Hermann, Wieland

2014-05-01

359

IMAGES, IMAGES, IMAGES  

SciTech Connect

The role of images of information (charts, diagrams, maps, and symbols) for effective presentation of facts and concepts is expanding dramatically because of advances in computer graphics technology, increasingly hetero-lingual, hetero-cultural world target populations of information providers, the urgent need to convey more efficiently vast amounts of information, the broadening population of (non-expert) computer users, the decrease of available time for reading texts and for decision making, and the general level of literacy. A coalition of visual performance experts, human engineering specialists, computer scientists, and graphic designers/artists is required to resolve human factors aspects of images of information. The need for, nature of, and benefits of interdisciplinary effort are discussed. The results of an interdisciplinary collaboration are demonstrated in a product for visualizing complex information about global energy interdependence. An invited panel will respond to the presentation.

Marcus, A.

1980-07-01

360

Patient-specific dosimetry of conventional and intensity modulated radiation therapy using a novel full Monte Carlo phase space reconstruction method from electronic portal images  

Microsoft Academic Search

Electronic portal imagers have promising dosimetric applications in external beam radiation therapy. In this study a patient dose computation algorithm based on Monte Carlo (MC) simulations and on portal images is developed and validated. The patient exit fluence from primary photons is obtained from the portal image after correction for scattered radiation. The scattered radiation at the portal imager and

Geneviève Jarry; Frank Verhaegen

2007-01-01

361

Patient-specific dosimetry of conventional and intensity modulated radiation therapy using a novel full Monte Carlo phase space reconstruction method from electronic portal images  

Microsoft Academic Search

Electronic portal imagers have promising dosimetric applications in external beam radiation therapy. In this study a patient dose computation algorithm based on Monte Carlo (MC) simulations and on portal images is developed and validated. The patient exit fluence from primary photons is obtained from the portal image after correction for scattered radiation. The scattered radiation at the portal imager and

362

CT imaging as a prognostic indicator for patients with pulmonary injury from acute paraquat poisoning  

PubMed Central

Objective: CT imaging may be an effective diagnostic method for assessing the extent and progression of pulmonary injury in patients with acute paraquat (PQ) poisoning. Methods: A retrospective review of 78 patients with acute PQ poisoning (survivor group, n=42; non-survivor group, n=36) was conducted to examine the lung segment involvement and CT image characteristics from baseline (first CT scan at a mean of 2.4 days after poisoning) to treatment time (second CT scan 3 days after the first). We examined the association between prognosis and pulmonary lesions indicated by characteristic effusion, fibrosis and consolidation in CT images. Results: Significant differences were apparent in CT images at baseline and after 3 days between the survivor and the non-survivor groups, with higher levels of pulmonary segment involvement, effusion, consolidation and fibrosis observed in the non-survivor group at baseline (p<0.05). The non-survivor group also showed rapid lesion progression. The receiver operating characteristic curve indicated that the best prognostic value of baseline CT scanning was achieved when performed 2–3 days following the initial exposure. Conclusion: Prognosis correlated with increasing lung segment involvement, extent of disease characteristics visualised using CT and speed of lesion progression from baseline. Prognostic evaluation using CT scanning can be used to effectively provide earlier treatment for patients at risk for severe complications associated with PQ toxicity, such as acidosis; leukocytosis; and renal, hepatic and pancreatic failures. Advances in knowledge: Chest CT scan can be used 2–3 days following acute PQ poisoning to determine prognosis.

Liu, P; Qiao, P; Zhou, J; Zhao, Y; Xing, X

2013-01-01

363

Factors affecting patient compliance in the acute setting: an analysis of 20,000 imaging reports.  

PubMed

The aim of this study was to identify the risk factors associated with noncompliance of recommendations made by emergency radiologists. Between March 2012 and August 2012, our team retrospectively reviewed 20,000 consecutive emergency department (ED) patients receiving imaging to assess how often emergency radiologists made recommendations, how often they were followed, and what factors were associated with noncompliance. Faculty (Radiology or Emergency Medicine) were considered senior if they had been practicing for >5 years post residency/fellowship training. Faculty practicing <5 years were considered junior physicians. The following data was extracted from the electronic medical records and the hospital information system: recommendation in imaging report, age, gender, race (Caucasian, African-American, and others), insurance status, primary care contact, distance from the hospital to patient residence, and primary language. Recommendations were categorized as follows: (1) immediate follow-up, (2) follow-up 1-4 weeks, (3) follow-up 1-3 months, (4) follow-up 4-6 months, (5) follow-up 7-12 months, and (6) clinical/laboratory follow-up recommendations irrespective of time. We identified 1,650 recommendations (1,650/20,000?=?8.25 %). Using a one-to-one logistic regression analysis, the following factors were significant (P?imaging (RAI) is multifactorial. Primary and/or referring physicians should take notice of the aforementioned compliance trends and mitigating factors, adopt systematic safety measures and create interdepartmental dialogue with radiology to ensure compliance, and counsel and educate patients about the importance of imaging recommendations. PMID:24615661

Shuaib, Waqas; Vijayasarathi, Arvind; Johnson, Jamlik-Omari; Salastekar, Ninad; He, Qing; Maddu, Kiran Kumar; Khosa, Faisal

2014-08-01

364

Differences in body image between anorexics and in-vitro-fertilization patients - a study with Body Grid  

PubMed Central

Objectives: The purpose of the investigation was to explore the body image disturbance of anorexics and in-vitro-fertilization patients (IvF-patients) with Body Grid and Body Identity Plot. Methods: The paper reports on an empirical study conducted with 32 anorexic patients and 30 IvF-patients. The structure of the body image was derived from the Body Grid, an idiographic approach following the Role Repertory Grid developed by George A. Kelly [17]. The representation of the body image and the degree of body-acceptance is represented graphically. Results: By the Body Grid and Body Identity Plot measures we were able to identify important differences in body image between anorexics and IvF-patients. Conclusion: The tendencies of dissociation in the body image of anorexics which we found must be seen in the sense of a specific body image disturbance which differs significantly from the body-experience profile of IvF-patients. With the grid approach it was possible to elicit the inner structure of body image and determine the acceptance of the body and integration of single body parts.

Borkenhagen, Ada; Klapp, Burghard F.; Schoeneich, Frank; Brahler, Elmar

2005-01-01

365

Corticospinal Tract Change during Motor Recovery in Patients with Medulla Infarct: A Diffusion Tensor Imaging Study  

PubMed Central

Diffusion tensor imaging (DTI) and tractography (DTT) provide a powerful vehicle for investigating motor recovery mechanisms. However, little is known about these mechanisms in patients with medullary lesions. We used DTI and DTT to evaluate three patients presenting with motor deficits following unilateral medulla infarct. Patients were scanned three times during 1 month (within 7, 14, and 30 days after stroke onset). Fractional anisotropy (FA) values were measured in the medulla, cerebral peduncle, and internal capsule. The three-dimensional corticospinal tract (CST) was reconstructed using DTT. Patients 1 and 2 showed good motor recovery after 14 days, and the FA values of their affected CST were slightly decreased. DTTs demonstrated that the affected CST passed along periinfarct areas and that tract integrity was preserved in the medulla. Patient 3 had the most obvious decrease in FA values along the affected CST, with motor deficits of the right upper extremity after 30 days. The affected CST passed through the infarct and was disrupted in the medulla. In conclusion, DTI can detect the involvement and changes of the CST in patients with medulla infarct during motor recovery. The degree of degeneration and spared periinfarct CST compensation may be an important motor recovery mechanism.

Zhang, Miao; Ma, Qingfeng; Lu, Jie; Li, Kuncheng

2014-01-01

366

Prognostic value of exercise thallium-201 imaging in patients presenting for evaluation of chest pain  

SciTech Connect

Accurate prognostic information is important in determining optimal management of patients presenting for evaluation of chest pain. In this study, the ability of exercise thallium-201 myocardial imaging to predict future cardiac events (cardiovascular death or nonfatal myocardial infarction) was correlated with clinical, coronary and left ventricular angiographic and exercise electrocardiographic data in 139 consecutive, nonsurgically managed patients followed-up over a 3 to 5 year period (mean follow-up, 3.7 +/- 0.9), using a logistic regression analysis. Among patients without prior myocardial infarction (100 of 139), the number of myocardial segments with transient thallium-201 defects was the only statistically significant predictor of future cardiac events when all patient variables were evaluated. Among patients with myocardial infarction before evaluation (39 of 139), angiographic ejection fraction was the only significant predictor of future cardiac events when all variables were considered. This study suggests an approach to evaluate the risk of future cardiac events in patients with possible ischemic heart disease.

Brown, K.A.; Boucher, C.A.; Okada, R.D.; Guiney, T.E.; Newell, J.B.; Strauss, H.W.; Pohost, G.M.

1983-04-01

367

Assessment of signs of foot infection in diabetes patients using photographic foot imaging and infrared thermography.  

PubMed

Abstract Background: Patients with diabetic foot disease require frequent screening to prevent complications and may be helped through telemedical home monitoring. Within this context, the goal was to determine the validity and reliability of assessing diabetic foot infection using photographic foot imaging and infrared thermography. Subjects and Methods: For 38 patients with diabetes who presented with a foot infection or were admitted to the hospital with a foot-related complication, photographs of the plantar foot surface using a photographic imaging device and temperature data from six plantar regions using an infrared thermometer were obtained. A temperature difference between feet of >2.2°C defined a "hotspot." Two independent observers assessed each foot for presence of foot infection, both live (using the Perfusion-Extent-Depth-Infection-Sensation classification) and from photographs 2 and 4 weeks later (for presence of erythema and ulcers). Agreement in diagnosis between live assessment and (the combination of?) photographic assessment and temperature recordings was calculated. Results: Diagnosis of infection from photographs was specific (>85%) but not very sensitive (<60%). Diagnosis based on hotspots present was sensitive (>90%) but not very specific (<25%). Diagnosis based on the combination of photographic and temperature assessments was both sensitive (>60%) and specific (>79%). Intra-observer agreement between photographic assessments was good (Cohen's ?=0.77 and 0.52 for both observers). Conclusions: Diagnosis of foot infection in patients with diabetes seems valid and reliable using photographic imaging in combination with infrared thermography. This supports the intended use of these modalities for the home monitoring of high-risk patients with diabetes to facilitate early diagnosis of signs of foot infection. PMID:24690146

Hazenberg, Constantijn E V B; van Netten, Jaap J; van Baal, Sjef G; Bus, Sicco A

2014-06-01

368

Adaptive optics-assisted optical coherence tomography for imaging of patients with age related macular degeneration  

NASA Astrophysics Data System (ADS)

We developed an optical coherence tomography (OCT) prototype with a sample arm that uses a 3.4 mm beam, which is considerably larger than the 1.2 to 1.5 mm beam that is used in commercialized OCT systems. The system is equipped with adaptive optics (AO), and to distinguish it from traditional AO-OCT systems with a larger 6 mm beam we have coined this concept AO-assisted OCT. Compared to commercialized OCT systems, the 3.4 mm aperture combined with AO improves light collection efficiency and imaging lateral resolution. In this paper, the performance of the AOa-OCT system was compared to a standard OCT system and demonstrated for imaging of age-related macular degeneration (AMD). Measurements were performed on the retinas of three human volunteers with healthy eyes and on one eye of a patient diagnosed with AMD. The AO-assisted OCT system imaged retinal structures of healthy human eyes and a patient eye affected by AMD with higher lateral resolution and a 9° by 9° field of view. This combination of a large isoplanatic patch and high lateral resolution can be expected to fill a gap between standard OCT with a 1.2 mm beam and conventional AO-OCT with a 6 mm beam and a 1.5° by 1.5° isoplanatic patch.

Sudo, Kenta; Cense, Barry

2013-03-01

369

Automatic registration of portal images and volumetric CT for patient positioning in radiation therapy.  

PubMed

The efficacy of radiation therapy treatment depends on the patient setup accuracy at each daily fraction. A significant problem is reproducing the patient position during treatment planning for every fraction of the treatment process. We propose and evaluate an intensity based automatic registration method using multiple portal images and the pre-treatment CT volume. We perform both geometric and radiometric calibrations to generate high quality digitally reconstructed radiographs (DRRs) that can be compared against portal images acquired right before treatment dose delivery. We use a graphics processing unit (GPU) to generate the DRRs in order to gain computational efficiency. We also perform a comparative study on various similarity measures and optimization procedures. Simple similarity measure such as local normalized correlation (LNC) performs best as long as the radiometric calibration is carefully done. Using the proposed method, we achieved better than 1mm average error in repositioning accuracy for a series of phantom studies using two open field (i.e., 41 cm2) portal images with 90 degrees vergence angle. PMID:16150629

Khamene, Ali; Bloch, Peter; Wein, Wolfgang; Svatos, Michelle; Sauer, Frank

2006-02-01

370

Expandable tumor prostheses in children.  

PubMed

Any surgical resection in the lower extremities in children will cause a leg length discrepancy from physeal resection. To avoid the resulting functional deficit, leg length discrepancy must be reconciled with surgical techniques to approximate equal leg lengths at skeletal maturity. Currently there are several manufacturers who offer options for prosthetic reconstruction with expandable implants. These implants can be expanded to a length projected on the basis of three factors: the length of bone resected, the anticipated future growth of the contralateral extremity, and the estimated discrepancy of limb length at skeletal maturity. In this article, we review the basic principles and guidelines for prediction of remaining bone growth and planning lengthening in children, and present the currently available expandable prostheses and the evolution performed over time. PMID:22517686

Mavrogenis, A F; Papagelopoulos, P J; Coll-Mesa, L; Pala, E; Colangeli, M; Manfrini, M; Ruggieri, P

2012-01-01

371

Pelvic Floor Magnetic Resonance Imaging after Neonatal Single Stage Reconstruction in Male Patients With Classic Bladder Exstrophy  

Microsoft Academic Search

PurposeWe evaluate a magnetic resonance imaging (MRI) protocol used to study the pelvic floor anatomy in male patients following neonatal single stage complete bladder exstrophy and epispadias repair with osteotomies.

SAREL HALACHMI; WALID FARHAT; OSNAT KONEN; AZRA KHAN; JOHN HODAPP; DARIUS J. BAGLI; GORDON A. McLORIE; ANTOINE E. KHOURY

2003-01-01

372

Federal government expands compliance initiatives.  

PubMed

In 1995, the Federal government initiated Operation Restore Trust to increase enforcement of fraud and abuse regulations in Medicare and Medicaid programs. With the success of the original initiative, the government is expanding the project to additional states and program areas. The initial scrutiny of home health agencies, nursing homes, hospice care, and durable medical equipment is being expanded to managed care plans and acute care hospitals with an eye toward DRG creep. To manage this increased enforcement activity, healthcare organizations should institute comprehensive corporate compliance programs. Such programs should provide a framework that delineates responsibilities and provides a systematic means to resolve issues in a timely manner. PMID:10170318

Dugan, J K

1997-09-01

373

Transit Dosimetry for Patient Treatment Verification with an Electronic Portal Imaging Device  

NASA Astrophysics Data System (ADS)

The complex and individualized photon fluence patterns constructed during intensity modulated radiation therapy (IMRT) treatment planning must be verified before they are delivered to the patient. There is a compelling argument for additional verification throughout the course of treatment due to the possibility of data corruption, unintentional modification of the plan parameters, changes in patient anatomy, errors in patient alignment, and even mistakes in identifying the correct patient for treatment. Amorphous silicon (aSi) Electronic Portal Imaging Devices (EPIDs) can be utilized for IMRT verification. The goal of this thesis is to implement EPID transit dosimetry, measurement of the dose at a plane behind the patient during their treatment, within the clinical process. In order to achieve this goal, a number of the EPID's dosimetric shortcomings were studied and subsequently resolved. Portal dose images (PDIs) acquired with an aSi EPID suffer from artifacts related to radiation backscattered asymmetrically from the EPID support structure. This backscatter signal varies as a function of field size (FS) and location on the EPID. Its presence can affect pixel values in the measured PDI by up to 3.6%. Two methods to correct for this artifact are offered: discrete FS specific correction matrices and a single generalized equation. The dosimetric comparison between the measured and predicted through-air dose images for 49 IMRT treatment fields was significantly improved (p << .001) after the application of these FS specific backscatter corrections. The formulation of a transit dosimetry algorithm followed the establishment of the backscatter correction and a confirmation of the EPID's positional stability with linac gantry rotation. A detailed characterization of the attenuation, scatter, and EPID response behind an object in the beam's path is necessary to predict transit PDIs. In order to validate the algorithm's performance, 49 IMRT fields were delivered to a number of homogeneous and heterogeneous slab phantoms. A total of 33 IMRT fields were delivered to an anthropomorphic phantom. On average, 98.1% of the pixels in the dosimetric comparison between the measured and predicted transit dose images passed a 3%/3mm gamma analysis. Further validation of the transit dosimetry algorithm was performed on nine human subjects under an institutional review board (IRB) approved protocol. The algorithm was shown to be feasible for patient treatment verification. Comparison between measured and predicted transit dose images resulted in an average of 89.1% of pixels passing a 5%/3mm gamma analysis. A case study illustrated the important role that EPID transit dosimetry can play in indicating when a treatment delivery is inconsistent with the original plan. The impact of transit dosimetry on the clinical workflow for these nine patients was analyzed to identify improvements that could be made to the procedure in order to ease widespread clinical implementation. EPID transit dosimetry is a worthwhile treatment verification technique that strikes a balance between effectiveness and efficiency. This work, which focused on the removal of backscattered radiation artifacts, verification of the EPID's stability with gantry rotation, and the formulation and validation of a transit dosimetry algorithm, has improved the EPID's dosimetric performance. Future research aimed at online transit verification would maximize the benefit of transit dosimetry and greatly improve patient safety.

Berry, Sean L.

374

Expanding Criteria for Resectability of Colorectal Liver Metastases  

Microsoft Academic Search

Surgical resection is the treatment of choice in patients with colorectal liver metastases, with 5-year survival rates reported in the range of 40%-58%. Over the past 10 years, there has been an impetus to expand the crite- ria for defining resectability for patients with colorectal metastases. In the past, such features as the number of metastases (three to four), the

TIMOTHY M. PAWLIK; R ICHARD D. SCHULICK; M ICHAEL A. CHOTI

2008-01-01

375

Evaluation of patient dose using a virtual CT scanner: Applications to 4DCT simulation and Kilovoltage cone-beam imaging  

Microsoft Academic Search

This work evaluates the effects of patient size on radiation dose from simulation imaging studies such as four-dimensional computed tomography (4DCT) and kilovoltage cone-beam computed tomography (kV-CBCT). 4DCT studies are scans that include temporal information, frequently incorporating highly over-sampled imaging series necessary for retrospective sorting as a function of respiratory phase. This type of imaging study can result in a

J. J. DeMarco; M. F. McNitt-Gray; C. H. Cagnon; E. Angel; N. Agazaryan; M. Zankl

2008-01-01

376

L-2-Hydroxyglutaric aciduria: clinical, biochemical and magnetic resonance imaging in six Portuguese pediatric patients.  

PubMed

We present clinical, biochemical and cranial magnetic resonance imaging data of six pediatric patients with L-2-hydroxyglutaric aciduria. All the children have the same ethic origin and lived in the northern area of Portugal. Our findings reinforce the described phenotype of this rare metabolic disease with mental deficiency, severe cerebellar dysfunction, mild extrapyramidal and pyramidal symptoms, progressive macrocephaly and seizures. Magnetic resonance imaging revealed subcortical leukoencephalopathy, cerebellar atrophy and signal changes in the putamina and dentate nuclei. These were similar to those of the previous reports in all patients. The urinary excretion of L-2-hydroxyglutaric acid was variably increased in all patients. The other persistent biochemical abnormality was hyperlysinemia. We have found a strong correlation between the severity of the clinical manifestations and the extension of the lesions in the neuroimaging studies. There was no correlation between the clinical findings and the amount of urinary excretion of L-2-hydroxyglutaric acid. We report the second case in the literature of a cerebral thalamic tumor in L-2-hydroxyglutaric aciduria; neuropathological examination of the surgical biopsy demonstrated a diffuse fibrillary astrocytoma. PMID:9187477

Barbot, C; Fineza, I; Diogo, L; Maia, M; Melo, J; Guimarães, A; Pires, M M; Cardoso, M L; Vilarinho, L

1997-06-01

377

Functional brain abnormalities localized in 55 chronic tinnitus patients: fusion of SPECT coincidence imaging and MRI  

PubMed Central

Tinnitus is often defined as the perception of sounds or noise in the absence of any external auditory stimuli. The pathophysiology of subjective idiopathic tinnitus remains unclear. The aim of this study was to investigate the functional brain activities and possible involved cerebral areas in subjective idiopathic tinnitus patients by means of single photon emission computerized tomography (SPECT) coincidence imaging, which was fused with magnetic resonance imaging (MRI). In this cross-sectional study, 56 patients (1 subject excluded) with subjective tinnitus and 8 healthy controls were enrolled. After intravenous injection of 5?mCi F18-FDG (fluorodeoxyglucose), all subjects underwent a brain SPECT coincidence scan, which was then superimposed on their MRIs. In the eight regions of interest (middle temporal, inferotemporal, medial temporal, lateral temporal, temporoparietal, frontal, frontoparietal, and parietal areas), the more pronounced values were represented in medial temporal, inferotemporal, and temporoparietal areas, which showed more important proportion of associative auditory cortices in functional attributions of tinnitus than primary auditory cortex. Brain coincidence SPECT scan, when fused on MRI is a valuable technique in the assessment of patients with tinnitus and could show the significant role of different regions of central nervous system in functional attributions of tinnitus.

Farhadi, Mohammad; Mahmoudian, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaee, Mohammad; Ahmadizadeh, Majid; Ghasemikian, Khosro; Gholami, Saeid; Ghoreyshi, Esmaeel; Beyty, Saeid; Shamshiri, Ahmadreza; Madani, Sedighe; Bakaev, Valery; Moradkhani, Seddighe; Raeisali, Gholamreza

2010-01-01

378

Functional brain abnormalities localized in 55 chronic tinnitus patients: fusion of SPECT coincidence imaging and MRI.  

PubMed

Tinnitus is often defined as the perception of sounds or noise in the absence of any external auditory stimuli. The pathophysiology of subjective idiopathic tinnitus remains unclear. The aim of this study was to investigate the functional brain activities and possible involved cerebral areas in subjective idiopathic tinnitus patients by means of single photon emission computerized tomography (SPECT) coincidence imaging, which was fused with magnetic resonance imaging (MRI). In this cross-sectional study, 56 patients (1 subject excluded) with subjective tinnitus and 8 healthy controls were enrolled. After intravenous injection of 5 mCi F18-FDG (fluorodeoxyglucose), all subjects underwent a brain SPECT coincidence scan, which was then superimposed on their MRIs. In the eight regions of interest (middle temporal, inferotemporal, medial temporal, lateral temporal, temporoparietal, frontal, frontoparietal, and parietal areas), the more pronounced values were represented in medial temporal, inferotemporal, and temporoparietal areas, which showed more important proportion of associative auditory cortices in functional attributions of tinnitus than primary auditory cortex. Brain coincidence SPECT scan, when fused on MRI is a valuable technique in the assessment of patients with tinnitus and could show the significant role of different regions of central nervous system in functional attributions of tinnitus. PMID:20068582

Farhadi, Mohammad; Mahmoudian, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaee, Mohammad; Ahmadizadeh, Majid; Ghasemikian, Khosro; Gholami, Saeid; Ghoreyshi, Esmaeel; Beyty, Saeid; Shamshiri, Ahmadreza; Madani, Sedighe; Bakaev, Valery; Moradkhani, Seddighe; Raeisali, Gholamreza

2010-04-01

379

Dynamic contrast-enhanced magnetic resonance imaging in patients with pulmonary arterial hypertension  

PubMed Central

Abstract Dynamic contrast–enhanced (DCE) time-resolved magnetic resonance (MR) imaging is a technique whereby the passage of an intravenous contrast bolus can be tracked through the pulmonary vascular system. The aim of this study was to investigate the prognostic significance of DCE-MR pulmonary blood transit times in patients with pulmonary arterial hypertension (PAH). Seventy-nine patients diagnosed with PAH underwent pulmonary DCE imaging at 1.5 T using a time-resolved three-dimensional spoiled gradient echo sequence. The prognostic significance of two DCE parameters, full width at half maximum (FWHM) of the first-pass clearance curve and pulmonary transit time (PTT), along with demographic and invasive catheter measurements, was evaluated by univariate and bivariate Cox proportional hazards regression and Kaplan-Meier analysis. DCE-MR transit times were most closely correlated with cardiac index (CI) and pulmonary vascular resistance index (PVRI) and were both found to be accurate for detecting reduced CI (FWHM area under the curve [AUC] at receiver operating characteristic analysis = 0.91 and PTT AUC = 0.92, respectively) and for detecting elevated PVRI (FWHM AUC = 0.88 and PTT AUC = 0.84, respectively). During the follow-up period, 25 patients died. Patients with longer measurements of FWHM (P = 0.0014) and PTT (P = 0.004) were associated with poor outcome at Kaplan-Meier analysis, and both parameters were strong predictors of adverse outcome from Cox proportional hazards analysis (P = 0.013 and 0.010, respectively). At bivariate analysis, DCE measurements predicted mortality independent of age, gender, and World Health Organization functional class; however, invasive hemodynamic indexes CI, PVRI, and DCE measurements were not independent of one another. In conclusion, DCE-MR transit times predict mortality in patients with PAH and are closely associated with clinical gold standards CI and PVRI.

Condliffe, Robin; Marshall, Helen; Elliot, Charlie; Kiely, David G.; Wild, Jim M.

2014-01-01