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Sample records for angiography nimiscad-non invasive

  1. Ultrahigh-speed non-invasive widefield angiography

    NASA Astrophysics Data System (ADS)

    Blatter, Cedric; Klein, Thomas; Grajciar, Branislav; Schmoll, Tilman; Wieser, Wolfgang; Andre, Raphael; Huber, Robert; Leitgeb, Rainer A.

    2012-07-01

    Retinal and choroidal vascular imaging is an important diagnostic benefit for ocular diseases such as age-related macular degeneration. The current gold standard for vessel visualization is fluorescence angiography. We present a potential non-invasive alternative to image blood vessels based on functional Fourier domain optical coherence tomography (OCT). For OCT to compete with the field of view and resolution of angiography while maintaining motion artifacts to a minimum, ultrahigh-speed imaging has to be introduced. We employ Fourier domain mode locking swept source technology that offers high quality imaging at an A-scan rate of up to 1.68 MHz. We present retinal angiogram over ˜48 deg acquired in a few seconds in a single recording without the need of image stitching. OCT at 1060 nm allows for high penetration in the choroid and efficient separate characterization of the retinal and choroidal vascularization.

  2. Non-invasive coronary angiography with multi-detector computed tomography: comparison to conventional X-ray angiography.

    PubMed

    Schoenhagen, Paul; Stillman, Arthur E; Halliburton, Sandy S; Kuzmiak, Stacie A; Painter, Tracy; White, Richard D

    2005-02-01

    Selective coronary angiography introduced clinical coronary imaging in the late 1950s. The angiographic identification of high-grade coronary lesions in patients with acute and chronic symptomatic coronary artery disease (CAD) led to the development of surgical and percutaneous coronary revascularization. However, the fact that CAD remains the major cause of death in North America and Europe demonstrates the need for novel, complementary diagnostic strategies. These are driven by the need to characterize both increasingly advanced disease stages but also early, asymptomatic disease development. Complex revascularization techniques for patients with advanced disease stages will initiate a growing demand for 3-dimensional coronary imaging and integration of imaging modalities with new mechanical therapeutic devices. An emerging focus is atherosclerosis imaging with the goal to identify subclinical disease stages as the basis for pharmacological intervention aimed at disease stabilization or reversal. Non-invasive coronary imaging with coronary multidetector computed tomographic angiography (MDCTA) allows both assessment of luminal stenosis and subclinical disease of the arterial wall. Its complementary role in the assessment of early and advanced stages of CAD is increasingly recognized.

  3. Non-diagnostic coronary artery calcification and stenosis: a correlation of coronary computed tomography angiography and invasive coronary angiography.

    PubMed

    Engel, Leif-Christopher; Thai, Wai-Ee; Medina-Zuluaga, Hector; Karolyi, Mihaly; Sidhu, Manavjot S; Maurovich-Horvat, Pal; Margey, Ronan; Pomerantsev, Eugene; Abbara, Suhny; Ghoshhajra, Brian B; Hoffmann, Udo; Liew, Gary Y

    2016-01-01

    Background Heavy coronary artery calcification (CAC) impairs diagnostic accuracy of coronary computed tomography angiography (cCTA) and is considered to be a major limitation. Purpose To investigate the effect of non-evaluable CAC seen on cCTA on clinical decision-making by determining the degree of subsequent invasive testing and to assess the relationship between non-evaluable segments containing CAC and significant stenosis as seen in invasive coronary angiography (ICA). Material and Methods The study comprised of 356 patients who underwent cCTA and subsequent ICA within 2 months between 2005 and 2009. Clinical reports were reviewed to identify the indications for referral to ICA. In a subset of 68 patients where non-diagnostic CAC on cCTA and significant stenosis on ICA were present in the same segment, we correlated and analyzed the underlying stenosis severity of the lesion on ICA to the cCTA. Lesions with CAC were analyzed in a standardized fashion by application of reading rules. Results Non-diagnostic CAC on cCTA prompted ICA in 5.6% of patients. CAC occurred at the site of maximum stenosis in segments with stenosis <50% (95.9% [47/49]), 50-69% (82.4% [28/34]), 70-99% (64.5% [31/48]), and 100% (33.3% [1/3]). At the point of maximum calcium deposit, non-obstructive disease was present in 61.2%. Application of reading rules resulted in a 44% reduction in non-diagnostic cCTA reads. Conclusion Severe CAC may prompt further investigation with ICA. There is less CAC with increasing lesion severity at the point of maximum stenosis. Additional application of reading rules improved non-diagnostic cCTA reads.

  4. Ethical issues for invasive cardiologists: Society for cardiovascular angiography and interventions.

    PubMed

    Cameron, Airlie A C; Laskey, Warren K; Sheldon, William C

    2004-02-01

    In view of the major impact of medical economic forces, rapidly changing technology, and other pressures on invasive cardiologists, the Society for Cardiovascular Angiography and Interventions determined that a statement of the ethical issues confronting the modern invasive cardiologist was needed. The various conflicts presented to the cardiologist in his or her roles as practicing clinician, administrator of the catheterization laboratory, educator, or clinical researcher were reviewed. In all instances, the major concern was determined to be the welfare of the patient no matter how forceful the pressures from various outside force or concerns for personal advancement might be.

  5. CT Angiography (CTA)

    MedlinePlus

    ... CT Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ...

  6. High-resolution magnetic resonance coronary angiography of the entire heart using a new blood-pool agent, NC100150 injection: comparison with invasive x-ray angiography in pigs.

    PubMed

    Johansson, L O; Nolan, M M; Taniuchi, M; Fischer, S E; Wickline, S A; Lorenz, C H

    1999-01-01

    Recent developments of novel magnetic resonance intravascular contrast agents with low T1 in blood and a long intravascular half-life will rapidly position magnetic resonance coronary angiography (MRCA) at the threshold of clinical application. This article describes the use of one such intravascular contrast agent for noninvasive coronary angiography and comparison with routine invasive x-ray angiography. Six domestic farm pigs with an artificial stenoses at the left circumflex were studied. NC100150 Injection, a new ultra-small superparmagnetic iron oxide (Nycomed Amersham Imaging, Oslo, Norway), was injected using a dose of 5.0 mg Fe/kg body weight. Scanning was done using a 1.5-T Gyroscan ACS-NT. A high-resolution electrocardiogram-triggered scan covering the entire heart was applied. Navigator echoes were used for respiratory triggering. In all animals the location of the stenoses detected with MRCA correlated well with x-ray angiography. The correlation factor between the grade of stenoses determined by MRCA and x-ray angiography was 0.993. MRCA using NC100150 Injection can depict the major coronary arteries and branches well. Decreases in vessel caliber detected by MRCA correlate well with x-ray angiography. The use of such intravascular contrast agents show great promise for clinical applications for noninvasive detection of coronary artery disease in humans.

  7. Cost analysis of non-invasive fractional flow reserve derived from coronary computed tomographic angiography in Japan.

    PubMed

    Kimura, Takeshi; Shiomi, Hiroki; Kuribayashi, Sachio; Isshiki, Takaaki; Kanazawa, Susumu; Ito, Hiroshi; Ikeda, Shunya; Forrest, Ben; Zarins, Christopher K; Hlatky, Mark A; Norgaard, Bjarne L

    2015-01-01

    Percutaneous coronary intervention (PCI) based on fractional flow reserve (FFRcath) measurement during invasive coronary angiography (CAG) results in improved patient outcome and reduced healthcare costs. FFR can now be computed non-invasively from standard coronary CT angiography (cCTA) scans (FFRCT). The purpose of this study is to determine the potential impact of non-invasive FFRCT on costs and clinical outcomes of patients with suspected coronary artery disease in Japan. Clinical data from 254 patients in the HeartFlowNXT trial, costs of goods and services in Japan, and clinical outcome data from the literature were used to estimate the costs and outcomes of 4 clinical pathways: (1) CAG-visual guided PCI, (2) CAG-FFRcath guided PCI, (3) cCTA followed by CAG-visual guided PCI, (4) cCTA-FFRCT guided PCI. The CAG-visual strategy demonstrated the highest projected cost ($10,360) and highest projected 1-year death/myocardial infarction rate (2.4 %). An assumed price for FFRCT of US $2,000 produced equivalent clinical outcomes (death/MI rate: 1.9 %) and healthcare costs ($7,222) for the cCTA-FFRCT strategy and the CAG-FFRcath guided PCI strategy. Use of the cCTA-FFRCT strategy to select patients for PCI would result in 32 % lower costs and 19 % fewer cardiac events at 1 year compared to the most commonly used CAG-visual strategy. Use of cCTA-FFRCT to select patients for CAG and PCI may reduce costs and improve clinical outcome in patients with suspected coronary artery disease in Japan.

  8. Invasive coronary angiography in patients with acute exacerbated COPD and elevated plasma troponin

    PubMed Central

    Pizarro, Carmen; Herweg-Steffens, Neele; Buchenroth, Martin; Schulte, Wolfgang; Schaefer, Christian; Hammerstingl, Christoph; Werner, Nikos; Nickenig, Georg; Skowasch, Dirk

    2016-01-01

    Background In acute exacerbation of COPD, increased plasma levels of cardiac troponin are frequent and associated with increased mortality. Thus, we aimed at prospectively determining the diagnostic value of coronary angiography in patients with exacerbated COPD and concomitantly elevated cardiac troponin. Patients and methods A total of 88 patients (mean age 72.9±9.2 years, 56.8% male) hospitalized for acute exacerbation of COPD with elevated plasma troponin were included. All patients underwent coronary angiography within 72 hours after hospitalization. Complementary 12-lead electrocardiogram, transthoracic echocardiography, pulmonary function, and angiological testing were performed. Results Coronary angiography objectified the presence of ischemic heart disease (IHD) in 59 patients (67.0%), of whom 34 patients (38.6% of total study population) underwent percutaneous coronary intervention. Among these 34 intervened patients, the vast majority (n=26, 76.5%) had no previously known IHD, whereas only eight out of 34 patients (23.5%) presented an IHD history. Patients requiring coronary intervention showed significantly reduced left ventricular ejection fraction (45.8%±13.1% vs 55.1%±13.3%, P=0.01) and a significantly more frequent electrocardiographic ST-segment depression (20.6% vs 7.4%, P=0.01). Neither additional laboratory parameters for inflammation and myocardial injury nor lung functional measurements differed significantly between the groups. Conclusion Angiographically confirmed IHD that required revascularization occurred in 38.6% of exacerbated COPD patients with elevated cardiac troponin. In this considerable portion of patients, coronary angiography emerged to be of diagnostic and therapeutic value. PMID:27695304

  9. Performance of dual-source CT with high pitch spiral mode for coronary stent patency compared with invasive coronary angiography

    PubMed Central

    Yang, Xia; Yu, Qiang; Dong, Wei; Fu, Zhen-Hong; Yang, Jun-Jue; Guo, Jun; Chen, Yun-Dai

    2016-01-01

    Objective To investigate the performance of dual-source computed tomography (DSCT) using high-pitch spiral (HPS) mode for coronary stents patency. Methods We conducted a prospective study on 120 patients with 260 previous stents implanted due to recurred suspicious symptoms of angina scheduled for invasive coronary angiography (ICA), while DSCT were conducted using HPS mode. Results There was no significant impact of age, body mass index or heat rate (HR) on image quality (P > 0.05), while HR variability had a slight impact on that (P < 0.05). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of DSCT in detection of in-stent restenosis (ISR) based per-patient were 92.3%, 96.7%, 88.9%, and 97.8%, respectively. And those based per-stent were 87%, 96.8%, 83.3%, and 97.7% with un-assessment stents, 97.4%, 99.5%, 97.4%, and 99.5% without un-assessment stents. There was significant difference on sensitivity, specificity, PPV and NPV between diameter ≥ 3.0 mm group (93.3%, 97.9%, 87.5%, and 98.9%) and diameter < 3.0 mm group (80%, 93.3%, 80.0%, and 93.3%) (P < 0.05), and that between stent number ≥ 3 group (82.3%, 77.8%, 66.7%, and 60%) with < 3 group (97.3%, 80%, 96.5%, and 75%). The effective dose of DSCT (1.4 ± 0.5 mSv) is significantly less than that by invasive coronary angiography [4.0 ± 0.8 mSv (P < 0.01)]. Conclusion DSCT using HPS mode provides good diagnostic performance on stent patency with lower effective dose in patients with HR < 65 beats/min. PMID:27928222

  10. Novel Non-invasive Estimation of Coronary Blood Flow using Contrast Advection in Computed Tomography Angiography

    NASA Astrophysics Data System (ADS)

    Eslami, Parastou; Seo, Jung-Hee; Rahsepar, Amirali; George, Richard; Lardo, Albert; Mittal, Rajat

    2014-11-01

    Coronary computed tomography angiography (CTA) is a promising tool for assessment of coronary stenosis and plaque burden. Recent studies have shown the presence of axial contrast concentration gradients in obstructed arteries, but the mechanism responsible for this phenomenon is not well understood. We use computational fluid dynamics to study intracoronary contrast dispersion and the correlation of concentration gradients with intracoronary blood flow and stenotic severity. Data from our CFD patient-specific simulations reveals that contrast dispersions are generated by intracoronary advection effects, and therefore, encode the coronary flow velocity. This novel method- Transluminal Attenuation Flow Encoding (TAFE) - is used to estimate the flowrate in phantom studies as well as preclinical experiments. Our results indicate a strong correlation between the values estimated from TAFE and the values measured in these experiments. The flow physics of contrast dispersion associated with TAFE will be discussed. This work is funded by grants from Coulter Foundation and Maryland Innovation Initiative. The authors have pending patents in this technology and RM and ACL have other financial interests associated with TAFE.

  11. Congenital coronary artery anomalies silent until geriatric age: non-invasive assessment, angiography tips, and treatment

    PubMed Central

    Rigatelli, Gianluca; Dell'Avvocata, Fabio; Van Tan, Nguyen; Daggubati, Rames; Nanijundappa, Aravinda

    2015-01-01

    Coronary artery anomalies (CAAs) may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial ischemia. The cardiovascular professional may be involved in their angiographic diagnosis, functional assessment and eventual endovascular treatment. A complete angiographic definition is mandatory in order to understand the functional effects and plan any intervention in CAAs: computed tomography and magnetic resonance imaging are useful non-invasive tools to detect three-dimensional morphology of the anomalies and its relationships with contiguous cardiac structures, whereas coronary arteriography remains the gold standard for a definitive anatomic picture. A practical idea of the possible functional significance is mandatory for deciding how to manage CAAs: non-invasive stress tests and in particular the invasive pharmacological stress tests with or without intravascular ultrasound monitoring can assess correctly the functional significance of the most CAAs. Finally, the knowledge of the particular endovascular techniques and material is of paramount importance for achieving technical and clinical success. CAAs represent a complex issue, which rarely involve the cardiovascular professional at different levels. A timely practical knowledge of the main issues regarding CAAs is important in the management of such entities. PMID:25678906

  12. Prognostic Value of Combined CT Angiography and Myocardial Perfusion Imaging versus Invasive Coronary Angiography and Nuclear Stress Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events: The CORE320 Multicenter Study.

    PubMed

    Chen, Marcus Y; Rochitte, Carlos E; Arbab-Zadeh, Armin; Dewey, Marc; George, Richard T; Miller, Julie M; Niinuma, Hiroyuki; Yoshioka, Kunihiro; Kitagawa, Kakuya; Sakuma, Hajime; Laham, Roger; Vavere, Andrea L; Cerci, Rodrigo J; Mehra, Vishal C; Nomura, Cesar; Kofoed, Klaus F; Jinzaki, Masahiro; Kuribayashi, Sachio; Scholte, Arthur J; Laule, Michael; Tan, Swee Yaw; Hoe, John; Paul, Narinder; Rybicki, Frank J; Brinker, Jeffrey A; Arai, Andrew E; Matheson, Matthew B; Cox, Christopher; Clouse, Melvin E; Di Carli, Marcelo F; Lima, João A C

    2017-03-14

    Purpose To compare the prognostic importance (time to major adverse cardiovascular event [MACE]) of combined computed tomography (CT) angiography and CT myocardial stress perfusion imaging with that of combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging. Materials and Methods This study was approved by all institutional review boards, and written informed consent was obtained. Between November 2009 and July 2011, 381 participants clinically referred for ICA and aged 45-85 years were enrolled in the Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) prospective multicenter diagnostic study. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. MACE was defined as revascularization (>30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded. Comparisons of 2-year survival (time to MACE) used standard Kaplan-Meier curves and restricted mean survival times bootstrapped with 2000 replicates. Results An MACE (49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia) occurred in 51 of 379 patients (13.5%). The 2-year MACE-free rates for combined CT angiography and CT perfusion findings were 94% negative for coronary artery disease (CAD) versus 82% positive for CAD and were similar to combined ICA and single photon emission CT findings (93% negative for CAD vs 77% positive for CAD, P < .001 for both). Event-free rates for CT angiography and CT perfusion versus ICA and single photon emission CT for either positive or negative results were not

  13. Minimally Invasive Coronary Angiography with Monochromatic X-Rays Developmental Studies Utilizing Synchrotron Radiation.

    NASA Astrophysics Data System (ADS)

    Otis, John Noel

    Iodine-containing compounds are used as contrast agents in obtaining X-ray images of blood vessels for medical diagnosis. If the X-ray contrast produced by iodine can be enhanced sufficiently relative to that produced by the intervening body tissues, it becomes possible to obtain images of arteries by introducing the contrast agent into the venous circulation rather than through an arterial catheter directly into the vessel under examination. This prospect is attractive because invasion of the arterial system is the chief cause of the medical complications that are encountered in the application of current angiographic procedures. An imaging system that shows promise of accomplishing this goal for examination of the coronary arteries has been developed for operation in an X-ray beam at the Stanford Synchrotron Radiation Laboratory. Iodine-selective contrast enhancement is achieved by logarithmic subtraction of two images of the same field. One of these images is formed by monochromatic X-rays of energy just above the characteristic iodine K-absorption edge at 33.17 keV, the other by X-rays of energy just below the edge. The computer-controlled imaging system acquires digitized images line by line while scanning the subject through a stationary X-ray beam of linear profile. At present, only synchrotron radiation can provide monochromatic X-ray beams of intensity sufficient to image the small and rapidly moving coronary arteries. Preliminary studies of static phantoms and in vivo studies of dogs establish the feasibility of using synchrotron radiation as the X-ray source for iodine-selective imaging with sensitivity and speed adequate for providing sharp images of coronary arteries after intravenous introduction of contrast agent. Application of the method to human subjects began with imaging studies of three patients in May, 1986.

  14. Pulmonary angiography

    MedlinePlus

    ... Pulmonary arteriography; Pulmonary angiogram; Angiogram of the lungs Images Pulmonary arteries References Jackson JE, Meaney JFM. Angiography. ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  15. Comparison of CT angiography and digital subtraction angiography in the diagnosis of aortic coarctation.

    PubMed

    Miabi, Zinat; Pourfathi, Hojjat; Midia, Mehran; Midia, Ramin; Parvizi, Rezayat

    2011-01-01

    There are several methods for the diagnosis and evaluation of coarctation of the aorta. Digital Subtraction Angiography (DSA) is the standard detection method, though it entails complications and side-effects. The aim of the present study was to compare Computed Tomography (CT) angiography with DSA for diagnosing aortic coarctation. We performed a cross-sectional study of 15 patients (11 males and four females aged between two and 30 years) referred to Tabriz Shahid Madani Hospital and Imaging Center between August 2005 and February 2006 with suspected aortic coarctation. All patients were subjected to DSA and CT angiography for diagnosis of aortic coarctation. The mean age of the patients was 14.6 years; 11 were male (74.4%) and four (26.6%) were female. The DSA and CT angiography results were comparable in all patients in terms of diagnosis and the detection of complications, particularly cardiovascular complications. However, CT angiography was less time-consuming to perform than DSA (p < 0.0001). In conclusion, CT angiography, comparableto DSA, diagnosed coarctation of aorta in all the patients. However, CT angiography is a non-invasive, cost effective procedure that takes significantly less time to carry out than DSA. Therefore, CT angiography is recommended as an appropriate method for diagnosing the coarctation of aorta.

  16. CT angiography - chest

    MedlinePlus

    Computed tomography angiography - thorax; CTA - lungs; Pulmonary embolism - CTA chest; Thoracic aortic aneurysm - CTA chest; Venous thromboembolism - CTA lung; Blood clot - CTA lung; Embolus - CTA lung; CT ...

  17. Indocyanine green video angiography

    NASA Astrophysics Data System (ADS)

    Frambach, Donald A.

    1994-06-01

    Over the last two years, ophthalmologists have begun to use indocyanine green angiography as a supplement to fluorescein angiography. Unlike fluorescein, indocyanine green absorbs near infrared and emits slightly longer infrared light. Therefore, indocyanine green angiography images structures deeper in the retina and through blood, pigment, and turbid serous fluid that accumulates in a number of diseases. In addition, indocyanine green shows very different properties of dye leakage than does fluorescein and this can be used to identify certain abnormal blood vessels that grow beneath the retinas of patients with macular degeneration. Finally, indocyanine green fluoresces only 4% as efficiently as fluorescein which has presented a major technical problem until highly amplified video systems have become available to ophthalmologists. We have used a scanning laser ophthalmoscope to perform video indocyanine green angiography at the Doheny Eye Institute since November, 1991. In this paper, I will present several clinical cases that demonstrate the clinical usefulness of indocyanine green angiography.

  18. Rationale and Design of the Dual Energy Computed Tomography for Ischemia Determination Compared to “Gold Standard” Non-invasive and Invasive Techniques (DECIDE-Gold): A Multicenter International Efficacy Diagnostic Study of Rest-Stress Dual-Energy Computed Tomography Angiography with Perfusion

    PubMed Central

    Truong, Quynh A.; Knaapen, Paul; Pontone, Gianluca; Andreini, Daniele; Leipsic, Jonathon; Carrascosa, Patricia; Lu, Bin; Branch, Kelley; Raman, Subha; Bloom, Stephen; Min, James K.

    2014-01-01

    BACKGROUND Dual-energy CT (DECT) has potential to improve myocardial perfusion for physiologic assessment of coronary artery disease (CAD). Diagnostic performance of rest-stress DECT perfusion (DECTP) is unknown. OBJECTIVE DECIDE-Gold is a prospective multicenter study to evaluate the accuracy of DECT to detect hemodynamic (HD) significant CAD, as compared to fractional flow reserve (FFR) as a reference standard. METHODS Eligible participants are subjects with symptoms of CAD referred for invasive coronary angiography (ICA). Participants will undergo DECTP, which will be performed by pharmacological stress, and participants will subsequently proceed to ICA and FFR. HD-significant CAD will be defined as FFR ≥ 0.80. In those undergoing myocardial stress imaging (MPI) by positron emission tomography (PET), single photon emission computed tomography (SPECT) or cardiac magnetic resonance (CMR) imaging, ischemia will be graded by % ischemic myocardium. Blinded core laboratory interpretation will be performed for CCTA, DECTP, MPI, ICA and FFR. RESULTS Primary endpoint is accuracy of DECTP to detect ≥ 1 HD-significant stenosis at the subject-level when compared to FFR. Secondary and tertiary endpoints are accuracies of combinations of DECTP at the subject and vessel levels compared to FFR and MPI. CONCLUSION DECIDE-Gold will determine the performance of DECTP for diagnosing ischemia. PMID:25549826

  19. Prognostic utility of coronary computed tomographic angiography

    PubMed Central

    Otaki, Yuka; Berman, Daniel S.; Min, James K.

    2013-01-01

    Coronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a noninvasive method that enables accurate detection and exclusion of anatomically obstructive coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. There are numerous potential advantages of CCTA beyond simply luminal stenosis assessment including quantification of atherosclerotic plaque volume as well as assessment of plaque composition, extent, location and distribution. In recent years, an array of studies has evaluated the prognostic utility of CCTA findings of CAD for the prediction of major adverse cardiac events, all-cause death and plaque instability. This prognostic information enhances risk stratification and, if properly acted upon, may improve medical therapy and/or behavioral changes that may enhance event-free survival. The goal of the present article is to summarize the current status of the prognostic utility of CCTA findings of CAD. PMID:23809386

  20. Multidetector computed tomography angiography of the abdomen.

    PubMed

    Güven, Koray; Acunaş, Bülent

    2004-10-01

    Multidetector computed tomography (MDCT) angiography has provided excellent opportunities for advancement of computed tomography (CT) technology and clinical applications. It has a wide range of applications in the abdomen including vascular pathologies either occlusive or aneurysmal; enables the radiologist to produce vascular mapping that clearly show tumor invasion of vasculature and the relationship of vessels to mass lesions. MDCTA can be used in preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation. MDCTA can also provide extremely valuable information in the evaluation of ischemic bowel disease, active Crohn disease, the extent and location of collateral vessels in cirrhosis.

  1. Aqueous Angiography with Fluorescein and Indocyanine Green in Bovine Eyes

    PubMed Central

    Huang, Alex S.; Saraswathy, Sindhu; Dastiridou, Anna; Begian, Alan; Legaspi, Hanz; Mohindroo, Chirayu; Tan, James C. H.; Francis, Brian A.; Caprioli, Joseph; Hinton, David R.; Weinreb, Robert N.

    2016-01-01

    Purpose We characterize aqueous angiography as a real-time aqueous humor outflow imaging (AHO) modality in cow eyes with two tracers of different molecular characteristics. Methods Cow enucleated eyes (n = 31) were obtained and perfused with balanced salt solution via a Lewicky AC maintainer through a 1-mm side-port. Fluorescein (2.5%) or indocyanine green (ICG; 0.4%) were introduced intracamerally at 10 mm Hg individually or sequentially. With an angiographer, infrared and fluorescent images were acquired. Concurrent anterior segment optical coherence tomography (OCT) was performed, and fixable fluorescent dextrans were introduced into the eye for histologic analysis of angiographically positive and negative areas. Results Aqueous angiography in cow eyes with fluorescein and ICG yielded high-quality images with segmental patterns. Over time, ICG maintained a better intraluminal presence. Angiographically positive, but not negative, areas demonstrated intrascleral lumens with anterior segment OCT. Aqueous angiography with fluorescent dextrans led to their trapping in AHO pathways. Sequential aqueous angiography with ICG followed by fluorescein in cow eyes demonstrated similar patterns. Conclusions Aqueous angiography in model cow eyes demonstrated segmental angiographic outflow patterns with either fluorescein or ICG as a tracer. Translational Relevance Further characterization of segmental AHO with aqueous angiography may allow for intelligent placement of trabecular bypass minimally invasive glaucoma surgeries for improved surgical results. PMID:27847692

  2. Angiography and the gastrointestinal bleeder

    SciTech Connect

    Baum, S.

    1982-05-01

    The role of angiography in the diagnosis and treatment of gastrointestinal hemorrhage is discussed. Three categories of gastrointestinal bleeding are considered: upper gastrointestinal bleeding due to gastroesophageal varices, upper gastrointestinal bleeding of arterial or capillary origin, and lower gastrointestinal bleeding. The advantages and disadvantages of angiography are compared with those of radionuclide scanning and endoscopy or colonoscopy. It is anticipated that, as radionuclide scans are more widely employed, angiography will eventually be performed only in those patients with positive scans.

  3. Cost-effectiveness of initial stress cardiovascular MR, stress SPECT or stress echocardiography as a gate-keeper test, compared with upfront invasive coronary angiography in the investigation and management of patients with stable chest pain: mid-term outcomes from the CECaT randomised controlled trial

    PubMed Central

    Thom, Howard; West, Nicholas E J; Hughes, Vikki; Dyer, Matthew; Buxton, Martin; Sharples, Linda D; Jackson, Christopher H; Crean, Andrew M

    2014-01-01

    Objectives To compare outcomes and cost-effectiveness of various initial imaging strategies in the management of stable chest pain in a long-term prospective randomised trial. Setting Regional cardiothoracic referral centre in the east of England. Participants 898 patients (69% man) entered the study with 869 alive at 2 years of follow-up. Patients were included if they presented for assessment of stable chest pain with a positive exercise test and no prior history of ischaemic heart disease. Exclusion criteria were recent infarction, unstable symptoms or any contraindication to stress MRI. Primary outcome measures The primary outcomes of this follow-up study were survival up to a minimum of 2 years post-treatment, quality-adjusted survival and cost-utility of each strategy. Results 898 patients were randomised. Compared with angiography, mortality was marginally higher in the groups randomised to cardiac MR (HR 2.6, 95% CI 1.1 to 6.2), but similar in the single photon emission CT-methoxyisobutylisonitrile (SPECT-MIBI; HR 1.0, 95% CI 0.4 to 2.9) and ECHO groups (HR 1.6, 95% CI 0.6 to 4.0). Although SPECT-MIBI was marginally superior to other non-invasive tests there were no other significant differences between the groups in mortality, quality-adjusted survival or costs. Conclusions Non-invasive cardiac imaging can be used safely as the initial diagnostic test to diagnose coronary artery disease without adverse effects on patient outcomes or increased costs, relative to angiography. These results should be interpreted in the context of recent advances in imaging technology. Trial registration ISRCTN 47108462, UKCRN 3696. PMID:24508847

  4. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography.

    PubMed

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-11-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH.

  5. Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography

    PubMed Central

    Junqueira, F P; Lima, C M A O; Coutinho, A C; Parente, D B; Bittencourt, L K; Bessa, L G P; Domingues, R C; Marchiori, E

    2012-01-01

    Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH. PMID:22932061

  6. Optical Coherence Tomography Angiography

    PubMed Central

    Gao, Simon S.; Jia, Yali; Zhang, Miao; Su, Johnny P.; Liu, Gangjun; Hwang, Thomas S.; Bailey, Steven T.; Huang, David

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a noninvasive approach that can visualize blood vessels down to the capillary level. With the advent of high-speed OCT and efficient algorithms, practical OCTA of ocular circulation is now available to ophthalmologists. Clinical investigations that used OCTA have increased exponentially in the past few years. This review will cover the history of OCTA and survey its most important clinical applications. The salient problems in the interpretation and analysis of OCTA are described, and recent advances are highlighted. PMID:27409483

  7. Pediatric digital subtraction angiography

    SciTech Connect

    Amundson, G.M.; Wesenberg, R.L.; Mueller, D.L.; Reid, R.H.

    1984-12-01

    Experience with intravenous digital subtraction angiography (DSA) in infants and children is limited, although its relative rate of performance, low complication rate, and diagnostic accuracy indicate great potential. The authors performed 87 DSA examinations (74 patients) and obtained sufficient detail to facilitate diagnosis in most cases. The major problems of patient movement and overlapping vessels can be minimized by judicious use of sedation and strict attention to technique. Exposure of patients to radiation has not been a limiting factor since our system uses low exposure factors. Our results demonstrate that DSA has wide applicability to many organ systems and is especially useful in intracranial disease and for preoperative evaluation of neoplasms.

  8. Coronary plaque imaging by coronary computed tomography angiography

    PubMed Central

    Sato, Akira

    2014-01-01

    Coronary computed tomography angiography (CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease (CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice. PMID:24876919

  9. Hepatic Artery Angiography and Embolization for Hemobilia Following Laparoscopic Cholecystectomy

    SciTech Connect

    Nicholson, Tony; Travis, Simon; Ettles, Duncan; Dyet, John; Sedman, Peter; Wedgewood, Kevin; Royston, Christopher

    1999-01-15

    Purpose: The effectiveness of angiography and embolization in diagnosis and treatment were assessed in a cohort of patients presenting with upper gastrointestinal hemorrhage secondary to hepatic artery pseudoaneurysm following laparoscopic cholecystectomy. Methods: Over a 6-year period 1513 laparoscopic cholecystectomies were carried out in our region. Nine of these patients (0.6%) developed significant upper gastrointestinal bleeding, 5-43 days after surgery. All underwent emergency celiac and selective right hepatic artery angiography. All were treated by coil embolization of the right hepatic artery proximal and distal to the bleeding point. Results: Pseudoaneurysms of the hepatic artery adjacent to cholecystectomy clips were demonstrated in all nine patients at selective right hepatic angiography. In three patients celiac axis angiography alone failed to demonstrate the pseudoaneurysm. Embolization controlled hemorrhage in all patients with no further bleeding and no further intervention. One patient developed a candidal liver abscess in the post-procedure period. All patients are alive and well at follow-up. Conclusion: Selective right hepatic angiography is vital in the diagnosis of upper gastrointestinal hemorrhage following laparoscopic cholecystectomy. Embolization offers the advantage of minimally invasive treatment in unstable patients, does not disrupt recent biliary reconstruction, allows distal as well as proximal control of the hepatic artery, and is an effective treatment for this potentially life-threatening complication.

  10. Optical projection angiography

    NASA Astrophysics Data System (ADS)

    Liao, Riwei; Wang, Mingyi; Zhang, Fuli; Han, Dingan; Wang, Ruikang K.; Yang, Guojian; Zeng, Yaguang

    2016-11-01

    We propose the optical projection angiography (OPA) based on lateral dynamic scattering light for visualizing a three-dimensional (3D) blood-flow network. In OPA, a pulsed laser source illuminates a live biological sample for eliminating digital camera integration effects. The 2D flow image can be obtained by separating the dynamic and static scattering light signal of each camera pixel in the frequency domain. Flow images at a different angle are combined to reconstruct the 3D volume of the sample to realize OPA. Moreover, as our experiment retains the bright-field optical projection tomography (OPT) setup, the OPA image for the circulatory system and the OPT image for the skeletal structure can simultaneously be reconstructed. The experimental results can potentially be applied in physiological development studies.

  11. Optical coherence angiography

    PubMed Central

    Wylęgała, Adam; Teper, Sławomir; Dobrowolski, Dariusz; Wylęgała, Edward

    2016-01-01

    Abstract Background: Retinal vascular diseases are one of the most common causes of blindness in the developed world. Optical Coherence Tomography Angiography (OCT-A) is a new noninvasive method that uses several algorithms to detect blood movement. This enables the creation of high-resolution vascular images with contrast depicting motionless tissue. Methods: This review presents the results of articles relevant to age-related macular degeneration (AMD), diabetic retinopathy (DR), and OCT-A. The OCT-A technique can successfully be used in the diagnosis of neovascularization, retinal vein occlusion (RVO) and retinal artery occlusion (RAO), vessel abnormalities and even anterior segment neovascularization. OCT-A can also be applied to compute data such as vessel density, and flow index in both superficial and deep plexuses. Results: Many studies have compared fluorescein angiography with OCT-A. Other studies have reported differences in vascular density in AMD patients and have compared them with people having healthy eyes. Although OCT-A offers rapid picture acquisition, high repeatability and resolution, it also has many drawbacks. The most common are: motion artifacts, projections from overlying vessels and limited field of view. An interesting new application is the possibility to assess changes during antivascular endothelial growth factor (anti-VEGF) therapy. Another function of OCT-A is the possible application in the study of choriocapillaries in many fields of ocular pathology. Conclusion: OCT-A is a new promising method that allows the visualization of the retinal vascular network and the counting of blood flow parameters. This technique provides reliable images useful in clinical routines. PMID:27741104

  12. High resolution 3 Tesla contrast-enhanced MR angiography of the hands in Raynaud's disease.

    PubMed

    Walcher, J; Strecker, R; Goldacker, S; Winterer, J; Langer, M; Bley, T A

    2007-04-01

    Raynaud's disease is associated with disorders in blood circulation of the hands. The gold standard to visualise pathology of digital arteries is catheter angiography. Contrast-enhanced MR angiography (CE MRA) has developed even more as an alternative non-invasive method to digital subtraction angiography, mostly for pelvic or lower limb vessels. We report a case of primary Raynaud's disease with high-grade stenosis and an occlusion of the digital arteries. This case illustrates the benefit and efficiency of CE MRA at high fields in depicting location and extension of peripheral arterial alterations.

  13. Risks and Complications of Coronary Angiography: A Comprehensive Review

    PubMed Central

    Tavakol, Morteza; Ashraf, Salman; Brener, Sorin J.

    2012-01-01

    Coronary angiography and heart catheterization are invaluable tests for the detection and quantification of coronary artery disease, identification of valvular and other structural abnormalities, and measurement of hemodynamic parameters. The risks and complications associated with these procedures relate to the patient’s concomitant conditions and to the skill and judgment of the operator. In this review, we examine in detail the major complications associated with invasive cardiac procedures and provide the reader with a comprehensive bibliography for advanced reading. PMID:22980117

  14. CT angiography - head and neck

    MedlinePlus

    ... medlineplus.gov/ency/article/007677.htm CT angiography - head and neck To use the sharing features on this page, ... create pictures of the blood vessels in the head and neck. How the Test is Performed You will be ...

  15. Computed tomography imaging and angiography - principles.

    PubMed

    Kamalian, Shervin; Lev, Michael H; Gupta, Rajiv

    2016-01-01

    The evaluation of patients with diverse neurologic disorders was forever changed in the summer of 1973, when the first commercial computed tomography (CT) scanners were introduced. Until then, the detection and characterization of intracranial or spinal lesions could only be inferred by limited spatial resolution radioisotope scans, or by the patterns of tissue and vascular displacement on invasive pneumoencaphalography and direct carotid puncture catheter arteriography. Even the earliest-generation CT scanners - which required tens of minutes for the acquisition and reconstruction of low-resolution images (128×128 matrix) - could, based on density, noninvasively distinguish infarct, hemorrhage, and other mass lesions with unprecedented accuracy. Iodinated, intravenous contrast added further sensitivity and specificity in regions of blood-brain barrier breakdown. The advent of rapid multidetector row CT scanning in the early 1990s created renewed enthusiasm for CT, with CT angiography largely replacing direct catheter angiography. More recently, iterative reconstruction postprocessing techniques have made possible high spatial resolution, reduced noise, very low radiation dose CT scanning. The speed, spatial resolution, contrast resolution, and low radiation dose capability of present-day scanners have also facilitated dual-energy imaging which, like magnetic resonance imaging, for the first time, has allowed tissue-specific CT imaging characterization of intracranial pathology.

  16. Optical coherence tomography based angiography [Invited

    PubMed Central

    Chen, Chieh-Li; Wang, Ruikang K.

    2017-01-01

    Optical coherence tomography (OCT)-based angiography (OCTA) provides in vivo, three-dimensional vascular information by the use of flowing red blood cells as intrinsic contrast agents, enabling the visualization of functional vessel networks within microcirculatory tissue beds non-invasively, without a need of dye injection. Because of these attributes, OCTA has been rapidly translated to clinical ophthalmology within a short period of time in the development. Various OCTA algorithms have been developed to detect the functional micro-vasculatures in vivo by utilizing different components of OCT signals, including phase-signal-based OCTA, intensity-signal-based OCTA and complex-signal-based OCTA. All these algorithms have shown, in one way or another, their clinical values in revealing micro-vasculatures in biological tissues in vivo, identifying abnormal vascular networks or vessel impairment zones in retinal and skin pathologies, detecting vessel patterns and angiogenesis in eyes with age-related macular degeneration and in skin and brain with tumors, and monitoring responses to hypoxia in the brain tissue. The purpose of this paper is to provide a technical oriented overview of the OCTA developments and their potential pre-clinical and clinical applications, and to shed some lights on its future perspectives. Because of its clinical translation to ophthalmology, this review intentionally places a slightly more weight on ophthalmic OCT angiography. PMID:28271003

  17. Technical aspects of CT angiography.

    PubMed

    Kuszyk, B S; Fishman, E K

    1998-10-01

    The basic tasks of spiral CT acquisition, image processing, and image display are the foundations underlying CT angiography regardless of the anatomic region of interest. Volume rendering is a rapidly emerging image processing technique for creating three-dimensional (3D) images from CT datasets, which has important advantages over other 3D rendering techniques including maximum intensity projection and surface rendering. This articles reviews the techniques that are commonly used in CT angiography and key considerations for optimization.

  18. Computed tomography angiography in patients with active gastrointestinal bleeding.

    PubMed

    Reis, Fatima Regina Silva; Cardia, Patricia Prando; D'Ippolito, Giuseppe

    2015-01-01

    Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding.

  19. Noninvasive coronary artery angiography using electron beam computed tomography

    NASA Astrophysics Data System (ADS)

    Rumberger, John A.; Rensing, Benno J.; Reed, Judd E.; Ritman, Erik L.; Sheedy, Patrick F., II

    1996-04-01

    Electron beam computed tomography (EBCT), also known as ultrafast-CT or cine-CT, uses a unique scanning architecture which allows for multiple high spatial resolution electrocardiographic triggered images of the beating heart. A recent study has demonstrated the feasibility of qualitative comparisons between EBCT derived 3D coronary angiograms and invasive angiography. Stenoses of the proximal portions of the left anterior descending and right coronary arteries were readily identified, but description of atherosclerotic narrowing in the left circumflex artery (and distal epicardial disease) was not possible with any degree of confidence. Although these preliminary studies support the notion that this approach has potential, the images overall were suboptimal for clinical application as an adjunct to invasive angiography. Furthermore, these studies did not examine different methods of EBCT scan acquisition, tomographic slice thicknesses, extent of scan overlap, or other segmentation, thresholding, and interpolation algorithms. Our laboratory has initiated investigation of these aspects and limitations of EBCT coronary angiography. Specific areas of research include defining effects of cardiac orientation; defining the effects of tomographic slice thickness and intensity (gradient) versus positional (shaped based) interpolation; and defining applicability of imaging each of the major epicardial coronary arteries for quantitative definition of vessel size, cross-sectional area, taper, and discrete vessel narrowing.

  20. Computed tomography angiography in patients with active gastrointestinal bleeding*

    PubMed Central

    Reis, Fatima Regina Silva; Cardia, Patricia Prando; D'Ippolito, Giuseppe

    2015-01-01

    Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding. PMID:26811556

  1. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    MedlinePlus

    ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. ...

  2. Society for Cardiovascular Angiography and Interventions

    MedlinePlus

    ... jointly produced, collaborated with, or endorsed by the Society of Cardiovascular Angiography and Interventions. Press & News » Review ... SCAI Member? Create an Account Advertisement Advertisement The Society for Cardiovascular Angiography and Interventions Foundation, 1100 17th ...

  3. Duplex ultrasound assessment of femorodistal grafts: correlation with angiography.

    PubMed

    McShane, M D; Gazzard, V M; Clifford, P C; Hacking, C N; Fairhurst, J J; Humphries, K N; Birch, S J; Webster, J H; Chant, A D

    1987-12-01

    Fifty-eight grafts have been assessed using duplex scanning and ankle brachial pressure indices. This assessment is compared with the findings by angiography. Eighteen grafts were occluded and 40 patent. Duplex scanning defined graft status with a greater accuracy than pressure indices. Pressure indices alone would not differentiate "satisfactory" grafts from those with localised, haemodynamically significant disease. Only 55% of those grafts with localised stenoses demonstrated a fall of greater than 0.2 in ankle brachial pressure index after exercise. When the information obtained using pressure indices and duplex scanning was combined non-invasive assessment had a sensitivity of 86% and specificity of 94% for detection of localised, haemodynamically significant disease in patent grafts. Haemodynamically significant disease, as defined by angiography, can be detected and localised with duplex scanning complementing the use of pressure indices in graft assessment.

  4. Accuracy of distance measurements in biplane angiography

    NASA Astrophysics Data System (ADS)

    Toennies, Klaus D.; Oishi, Satoru; Koster, David; Schroth, Gerhard

    1997-05-01

    Distance measurements of the vascular system of the brain can be derived from biplanar digital subtraction angiography (2p-DSA). The measurements are used for planning of minimal invasive surgical procedures. Our 90 degree-fixed-angle G- ring angiography system has the potential of acquiring pairs of such images with high geometric accuracy. The sizes of vessels and aneurysms are estimated applying a fast and accurate extraction method in order to select an appropriate surgical strategy. Distance computation from 2p-DSA is carried out in three steps. First, the boundary of the structure to be measured is detected based on zero-crossings and closeness to user-specified end points. Subsequently, the 3D location of the center of the structure is computed from the centers of gravity of its two projections. This location is used to reverse the magnification factor caused by the cone-shaped projection of the x-rays. Since exact measurements of possibly very small structures are crucial to the usefulness in surgical planning, we identified mechanical and computational influences on the geometry which may have an impact on the measurement accuracy. A study with phantoms is presented distinguishing between the different effects and enabling the computation of an optimal overall exactness. Comparing this optimum with results of distance measurements on phantoms whose exact size and shape is known, we found, that the measurement error for structures of size of 20 mm was less than 0.05 mm on average and 0.50 mm at maximum. The maximum achievable accuracy of 0.15 mm was in most cases exceeded by less than 0.15 mm. This accuracy surpasses by far the requirements for the above mentioned surgery application. The mechanic accuracy of the fixed-angle biplanar system meets the requirements for computing a 3D reconstruction of the small vessels of the brain. It also indicates, that simple measurements will be possible on systems being less accurate.

  5. Mechanical aspects of CO₂ angiography.

    PubMed

    Corazza, Ivan; Rossi, Pier Luca; Feliciani, Giacomo; Pisani, Luca; Zannoli, Sebastiano; Zannoli, Romano

    2013-01-01

    The aim of this paper is to clarify some physical-mechanical aspects involved in the carbon dioxide angiography procedure (CO₂ angiography), with a particular attention to a possible damage of the vascular wall. CO₂ angiography is widely used on patients with iodine intolerance. The injection of a gaseous element, in most cases manually performed, requires a long training period. Automatic systems allow better control of the injection and the study of the mechanical behaviour of the gas. CO₂ injections have been studied by using manual and automatic systems. Pressures, flows and jet shapes have been monitored by using a cardiovascular mock. Photographic images of liquid and gaseous jet have been recorded in different conditions, and the vascular pressure rises during injection have been monitored. The shape of the liquid jet during the catheter washing phase is straight in the catheter direction and there is no jet during gas injection. Gas bubbles are suddenly formed at the catheter's hole and move upwards: buoyancy is the only governing phenomenon and no bubbles fragmentation is detected. The pressure rise in the vessel depends on the injection pressure and volume and in some cases of manual injection it may double the basal vascular pressure values. CO₂ angiography is a powerful and safe procedure which diffusion will certainly increase, although some aspects related to gas injection and chamber filling are not jet well known. The use of an automatic system permits better results, shorter training period and limitation of vascular wall damage risk.

  6. Efficacy of Patient Selection for Diagnostic Coronary Angiography in Suspected Coronary Artery Disease

    PubMed Central

    Costa Filho, Francisco Flávio; Chaves, Áurea Jacob; Ligabó, Lourenço Teixeira; dos Santos, Eduardo Moreira; da Silva, Danillo Taiguara; Puzzi, Marcelo Aguiar; Braga, Sérgio Luiz; Abizaid, Alexandre; Sousa, Amanda GMR

    2015-01-01

    Background Guidelines recommend that in suspected stable coronary artery disease (CAD), a clinical (non-invasive) evaluation should be performed before coronary angiography. Objective We assessed the efficacy of patient selection for coronary angiography in suspected stable CAD. Methods We prospectively selected consecutive patients without known CAD, referred to a high-volume tertiary center. Demographic characteristics, risk factors, symptoms and non-invasive test results were correlated to the presence of obstructive CAD. We estimated the CAD probability based on available clinical data and the incremental diagnostic value of previous non-invasive tests. Results A total of 830 patients were included; median age was 61 years, 49.3% were males, 81% had hypertension and 35.5% were diabetics. Non-invasive tests were performed in 64.8% of the patients. At coronary angiography, 23.8% of the patients had obstructive CAD. The independent predictors for obstructive CAD were: male gender (odds ratio [OR], 3.95; confidence interval [CI] 95%, 2.70 - 5.77), age (OR for 5 years increment, 1.15; CI 95%, 1.06 - 1.26), diabetes (OR, 2.01; CI 95%, 1.40 - 2.90), dyslipidemia (OR, 2.02; CI 95%, 1.32 - 3.07), typical angina (OR, 2.92; CI 95%, 1.77 - 4.83) and previous non-invasive test (OR 1.54; CI 95% 1.05 - 2.27). Conclusions In this study, less than a quarter of the patients referred for coronary angiography with suspected CAD had the diagnosis confirmed. A better clinical and non-invasive assessment is necessary, to improve the efficacy of patient selection for coronary angiography. PMID:26312552

  7. Angiography by Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Rubenstein, E.; Brown, G. S.; Giacomini, J. C.; Gordon, H. J.; Hofstadter, R.; Kernoff, R. S.; Otis, J. N.; Thomlinson, W.; Thompson, A. C.; Zeman, H. D.

    1987-01-01

    Because coronary disease represents the principal health problem in the Western, industrialized world, and because of the risks and costs associated with conventional methods of visualizing the coronary arteries, an effort has been underway at the Stanford Synchrotron Radiation Laboratory to develop a less invasive coronary imaging procedure based on iodine K-edge dichromography. A pair of line images, recorded within a few milliseconds of each other, is taken with two monochromatic X-ray beams whose energy closely brackets the K-edge of iodine, 33.17 keV. The logarithmic subtraction of the images produced by these beams results in an image which greatly enhances signals arising from attenuation by iodine and almost totally suppresses signals arising from attenuation by soft tissue and bone. The high sensitivity to iodine allows the visualization of arterial structures after an intravenous injection of contrast agent and its subsequent 20-30 fold dilution. The experiments began in 1979, with initial studies done on phantoms and excised pig hearts. The first images of anesthetized dogs were taken in 1982. The results of experiments on dogs will be reviewed, showing the stepwise evolution of the imaging system, leading to the use of the system on human subjects in 1986. The images recorded on human subjects will be described and the remaining problems discussed.

  8. Advances in non-invasive imaging of intracranial vascular disease.

    PubMed Central

    Jäger, H. R.; Grieve, J. P.

    2000-01-01

    Intra-arterial catheter angiography has, in the past, been the mainstay for the investigation of intracranial vascular disease. It is, however, invasive, usually requires in-patients admission, and is associated with a rate of neurological complications between 1% and 3%. In recent years, magnetic resonance angiography (MRA) and CT angiography (CTA) have emerged as non-invasive alternatives for imaging blood vessels and have made a significant impact on neuroradiological investigations. It is the purpose of this article to explain the basic technical principles of these two methods and to give an overview of their current clinical applications. PMID:10700757

  9. From the RSNA refresher courses: CT angiography: clinical applications in the abdomen.

    PubMed

    Fishman, E K

    2001-10-01

    The development of spiral computed tomography (CT) and subsequently multidetector CT has provided unparalleled opportunities for advancement of CT technology and clinical applications. One of the most influential developments has been CT angiography, which is the use of thin-section CT combined with postprocessing of imaging data by using a variety of three-dimensional reconstruction techniques to produce vascular maps that equal or exceed those provided by classic angiography in many applications. In the evaluation of pancreatic disease, the use of multidetector CT angiography enables the radiologist to produce vascular maps that clearly show tumor invasion of vasculature and the relationship of vessels to pancreatic masses. Anatomic areas for which the three-dimensional display is especially helpful include the confluence of the portal vein and the superior mesenteric vein and the more distal portions of the portal vein. Preliminary studies indicate that CT angiography may prove beneficial in the evaluation of ischemic bowel and active Crohn disease. CT angiography has proved extremely valuable for applications such as preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation, pretreatment planning for patients considered for hepatic arterial infusion chemotherapy, and pretreatment evaluation of portal vein patency for a variety of reasons. CT angiography can also provide supplemental information in patients with cirrhosis, upper gastrointestinal tract bleeding due to varices, or primary extrahepatic neoplasms.

  10. Angiography of nonneoplastic retroperitoneal masses

    SciTech Connect

    Lois, J.F.; Levin, D.C.; Hooshmand, I.

    1982-01-01

    Although noninvasive imaging modalities can be used to initially detect retroperitoneal masses, angiography is still desirable for several reasons in those cases in which surgery is contemplated. The latter can forewarn the surgeon as to possible hemorrhagic complications in highly vascular lesions. In some cases it can predict the malignant potential of the lesion. Finally, since these masses may derive blood supply from multiple sources, a vascular ''road map'' is provided to the surgeon. The angiographic findings of malignant retroperitoneal tumors are well known, but very little has been published dealing with benign nonneoplastic retroperitoneal masses. We have performed angiography in 11 surgically proven nonneoplastic retroperitoneal masses (9 inflammatory lesions, 2 hematomas). Major arterial or renal displacement occurred in 10. The 2 hematomas and 3 inflammatory lesions were totally avascular; 6 of the 9 inflammatory lesions revealed fine neovascularity and 5 of these 6 had an associated capillary blush. Sources of vascular supply included the lumbar, renal capsular, superior mesenteric, and gastroduodenal arteries. Although angiography is helpful in preoperative evaluation of retroperitoneal masses for the aforementioned reasons, it may be difficult or impossible to differentiate benign from malignant lesions based on the angiographic findings alone.

  11. Radiation dose measurements in coronary CT angiography

    PubMed Central

    Sabarudin, Akmal; Sun, Zhonghua

    2013-01-01

    Coronary computed tomography (CT) angiography is associated with high radiation dose and this has raised serious concerns in the literature. Awareness of various parameters for dose estimates and measurements of coronary CT angiography plays an important role in increasing our understanding of the radiation exposure to patients, thus, contributing to the implementation of dose-saving strategies. This article provides an overview of the radiation dose quantity and its measurement during coronary CT angiography procedures. PMID:24392190

  12. Digital subtraction angiography in children

    SciTech Connect

    Wagner, M.L.; Singleton, E.B.; Egan, M.E.

    1983-01-01

    Preliminary results with digital subtraction angiography in infants and children have shown this to be an excellent screening procedure and often diagnostic. The examination can be performed satisfactorily on outpatients. Sixty patients have undergone this examination for evaluation of suspected abnormalities of the aortic arch and its branches, intracranial arteries, pulmonary arteries, abdominal aorta and its branches, and peripheral vessels. Adequate sedation is mandatory to prevent motion artifacts. While the literature reports increasing use of central venous catheters for delivery of contrast material, the use of short catheters placed in an antecubital vein is satisfactory for the pediatric patient. Techniques of the procedures are described along with seven appropriate case examples.

  13. Radionuclide angiography: as diagnostic method for Wilms' tumor with direct extension into the heart.

    PubMed

    Avila Ramírez, E; Martínez Guerra, G

    1982-01-01

    Radioisotope angiography may be used as an initial study in Wilms' tumor. We report a patient who had a total nephrectomy but then had severe cardiovascular complications. These led to open heart surgery and removal of a tumor lodged in the right atrium. Radioisotope angiography, performed two weeks earlier, showed a "cold" image on the anterior wall of the right ventricle. This finding was later confirmed by other studies and finally at the time of a second operation. The purpose of this paper is to discuss the different methods employed in this case, to emphasize the risks attributed to each, and finally to suggest the use of non-invasive studies such as radioisotope angiography as a practical method of study in infancy.

  14. Transient cortical blindness after coronary artery angiography.

    PubMed

    Terlecki, Michał; Wojciechowska, Wiktoria; Rajzer, Marek; Jurczyszyn, Artur; Bazan-Socha, Stanisława; Bryniarski, Leszek; Czarnecka, Danuta

    2013-01-01

    Coronary angiography is the current gold standard for the diagnosis of ischemic heart disease and therefore the prevalence of percutaneous coronary procedures such as angiography and angioplasty is high. The occurrence of cerebral complications after coronary angiography and coronary angioplasty is low and it mainly includes transient ischemic attack and stroke. The prevalence of transient cortical blindness after X-ray contrast media is low and it is usually seen after cerebral angiography. Until now only a few cases of transient cortical blindness have been described after coronary artery angiography. Regarding the spread of coronary angiography worldwide and in Poland this complication is uniquely rare. A 32-year-old man with multiple extrasystolic ventricular arrhythmia suggesting Brugada syndrome diagnosis according to morphology of the left bundle branch block and with decreased left ventricular ejection fraction was admitted to the First Department of Cardiology and Hypertension, Medical College of the Jagiellonian University in Krakow. Coronary angiography was performed in order to exclude ischemic etiology of the observed abnormalities. No arteriosclerotic lesions were found in coronary arteries. Transient cortical blindness was observed directly after angiography which may have been caused by the neurotoxic effect of the used X-ray contrast medium. In ophthalmologic and neurologic examination as well as in the cerebral computed tomography scan no pathologies were found. Visual impairment disappeared totally within several hours.

  15. Doppler Fourier Domain Optical Coherence Tomography for Label-Free Tissue Angiography

    NASA Astrophysics Data System (ADS)

    Leitgeb, Rainer A.; Szkulmowski, Maciej; Blatter, Cedric; Wojtkowski, Maciej

    Information about tissue perfusion and the vascular structure is certainly most important for assessment of tissue state or personal health and the diagnosis of any pathological conditions. It is therefore of key medical interest to have tools available for both quantitative blood flow assessment as well as qualitative vascular imaging. The strength of optical techniques is the unprecedented level of detail even for small capillary structures or microaneurysms and the possibility to combine different techniques for additional tissue spectroscopy giving insight into tissue metabolism. There is an immediate diagnostic and pharmacological demand for high-resolution, label-free, tissue angiography and flow assessment that in addition allow for precise depth gating of flow information. The most promising candidate is Doppler optical coherence tomography (DOCT) being noncontact, label free, and without employing hazardous radiation. DOCT provides fully quantitative volumetric information about blood flow together with the vascular and structural anatomy. Besides flow quantification, analysis of OCT signal fluctuations allows to contrast moving scatterers in tissue such as red blood cells from static tissue. This allows for non-invasive optical angiography and yields high resolution even for smallest capillaries. Because of the huge potential of DOCT and lable-free optical angiography for diagnosis, the last years saw a rapid increase of publications in this field with many different approaches. The present chapter gives an overview over existing Doppler OCT approaches and angiography techniques. It furthermore discusses limitations and noise issues, and gives examples for angiography in the eye and the skin.

  16. Postmortem CT angiography: capabilities and limitations in traumatic and natural causes of death.

    PubMed

    Ross, Steffen G; Bolliger, Stephan A; Ampanozi, Garyfalia; Oesterhelweg, Lars; Thali, Michael J; Flach, Patricia M

    2014-01-01

    Whole-body postmortem computed tomographic (CT) angiography is a promising new development in forensic radiology that has the potential to improve vascular and soft-tissue imaging beyond levels currently achievable with unenhanced postmortem CT. Postmortem access to the vascular system and injection of contrast medium are different from those steps in clinical (antemortem) radiology. Because there is no circulation in a corpse that could transport or dilute a contrast medium, the injection must be performed by using a roller pump to fill the vasculature (arterial and venous) with a mixture of a water-soluble iodized contrast medium and polyethylene glycol. In contrast to a classic autopsy, postmortem CT angiography is a minimally invasive procedure. It allows the diagnosis of vascular lesions without the disruption or destruction of anatomic structures, which could result in a loss of evidence in a criminal investigation. Furthermore, postmortem CT angiography facilitates the display of vascular pathologic conditions in areas that are not typically covered with autopsy alone, such as the craniocervical junction and the small pelvis. Therefore, postmortem CT angiography adds substantial value to the classic forensic autopsy; cross-sectional data can be reevaluated objectively at any time and are fully reproducible as counterexpertise, which is as useful in the fields of forensic medicine and pathology as in clinical research. Familiarity with the capabilities of postmortem CT angiography may help radiologists working with forensic cases improve their diagnostic performance.

  17. "Geyser" leakage on fluorescein angiography.

    PubMed

    Levy, Jaime; Fagan, Xavier J; Lifshitz, Tova; Schneck, Marina

    2013-11-22

    An 82-year-old patient with diabetes was followed up due to moderate nonproliferative diabetic retinopathy with macular edema in the right eye. Visual acuity was 6/36. Focal macular laser was conducted (A). Three years later, the patient presented with blurry vision in the right eye. Visual acuity was 3/60. Vitreous hemorrhage was observed (B), and neovascularization of the disc was suspected (C). Fluorescein angiography (D, mid venous phase; E-F, recirculation phase) confirmed neovascularization of the disc and depicted a striking vertical leakage. Panretinal photocoagulation was started. Possible explanations for the "geyser" leakage may be either a partial posterior vitreous detachment allowing the fluorescein to track upwards but not elsewhere or a pocket of syneretic vitreous allowing the fluorescein passage in which to diffuse, much like the passage the blood would have taken.

  18. Renal angiography with iohexol and metrizoate

    SciTech Connect

    Toernquist, C.; Holtaes, S.

    1984-02-01

    The nephrotoxicity of the ionic contrast medium metrizoate was compared with that of nonionic iohexol when used for renal angiography. Fifteen patients who underwent renal angiography with metrizoate and 15 with iohexol were studied. Serum creatinine level, Cr-51-EDTA clearance, and urine albumin level were recorded before and after angiography. Metrizoate affected renal function, as indicated both by a transient decrease in glomerular filtration rate and by a transient albuminuria. Renal function was unaffected by iohexol. Furthermore, iohexol produced less subjective discomfort than metrizoate. There appeared to be no difference in the quality of the angiograms obtained with the two media.

  19. Digital subtraction angiography of the heart and lungs

    SciTech Connect

    Moodie, D.S.; Yiannikas, J.

    1986-01-01

    This book contains 12 chapters. Some of the chapter titles are: Physical Principles of Cardiac Digital Subtraction Angiography, The Use of Intravenous Digital Subtraction Angiography in Evaluating Patients with Complex Congenital Heart Disease, Exercise Intravenous Digital Subtraction Angiograpny, Cardiomyopathic and Cardiac Neoplastic Disease, Digital Subtraction Angiography in the Catheterization Laboratory, and Cardiac Digital Subtraction Angiography - Future Directions.

  20. Diagnostic accuracy of noninvasive coronary angiography with 320-detector row computed tomography.

    PubMed

    Nasis, Arthur; Leung, Michael C; Antonis, Paul R; Cameron, James D; Lehman, Sam J; Hope, Sarah A; Crossett, Marcus P; Troupis, John M; Meredith, Ian T; Seneviratne, Sujith K

    2010-11-15

    We sought to evaluate the diagnostic accuracy of noninvasive coronary angiography using 320-detector row computed tomography, which provides 16-cm craniocaudal coverage in 350 ms and can image the entire coronary tree in a single heartbeat, representing a significant advance from previous-generation scanners. We evaluated 63 consecutive patients who underwent 320-detector row computed tomography and invasive coronary angiography for the investigation of suspected coronary artery disease. Patients with known coronary artery disease were excluded. Computed tomographic (CT) studies were assessed by 2 independent observers blinded to results of invasive coronary angiography. A single observer unaware of CT results assessed invasive coronary angiographic images quantitatively. All available coronary segments were included in the analysis, regardless of size or image quality. Lesions with >50% diameter stenoses were considered significant. Mean heart rate was 63 ± 7 beats/min, with 6 patients (10%) in atrial fibrillation during image acquisition. Thirty-three patients (52%) and 70 of 973 segments (7%) had significant coronary stenoses on invasive coronary angiogram. Seventeen segments (2%) were nondiagnostic on computed tomogram and were assumed to contain significant stenoses on an "intention-to-diagnose" analysis. Sensitivity, specificity, and positive and negative predictive values of computed tomography for detecting significant stenoses were 94%, 87%, 88%, and 93%, respectively, by patient (n = 63), 89%, 95%, 82%, and 97%, respectively, by artery (n = 260), and 87%, 97%, 73%, and 99%, respectively, by segment (n = 973). In conclusion, noninvasive 320-detector row CT coronary angiography provides high diagnostic accuracy across all coronary segments, regardless of size, cardiac rhythm, or image quality.

  1. Multidetector CT angiography for acute gastrointestinal bleeding: technique and findings.

    PubMed

    Artigas, José M; Martí, Milagros; Soto, Jorge A; Esteban, Helena; Pinilla, Inmaculada; Guillén, Eugenia

    2013-01-01

    Acute gastrointestinal bleeding is a common reason for emergency department admissions and an important cause of morbidity and mortality. Factors that complicate its clinical management include patient debility due to comorbidities; intermittence of hemorrhage; and multiple sites of simultaneous bleeding. Its management, therefore, must be multidisciplinary and include emergency physicians, gastroenterologists, and surgeons, as well as radiologists for diagnostic imaging and interventional therapy. Upper gastrointestinal tract bleeding is usually managed endoscopically, with radiologic intervention reserved as an alternative to be used if endoscopic therapy fails. Endoscopy is often less successful in the management of acute lower gastrointestinal tract bleeding, where colonoscopy may be more effective. The merits of performing bowel cleansing before colonoscopy in such cases might be offset by the resultant increase in response time and should be weighed carefully against the deficits in visualization and diagnostic accuracy that would result from performing colonoscopy without bowel preparation. In recent years, multidetector computed tomographic (CT) angiography has gained acceptance as a first-line option for the diagnosis and management of lower gastrointestinal tract bleeding. In selected cases of upper gastrointestinal tract bleeding, CT angiography also provides accurate information about the presence or absence of active bleeding, its source, and its cause. This information helps shorten the total diagnostic time and minimizes or eliminates the need for more expensive and more invasive procedures.

  2. Optical Coherence Tomography Angiography of Iris Nevus: A Case Report

    PubMed Central

    Allegrini, Davide; Montesano, Giovanni; Pece, Alfredo

    2016-01-01

    Iris nevus is common: 6% of patients with suspected iris melanoma have lesions other than melanoma, and 36% of them are nevi. Iris nevus turns into melanoma in approximately 8% of cases at a mean of 15 years. This case report provides the first description of an iris tumor examined with iris optical coherence tomography angiography (OCTA) compared to iris fluorescein angiography (IFA). A 60-year-old man with a diagnosis of iris nevus in the left eye was referred to our department for IFA and iris OCTA. The iris vasculature in IFA was visible only in the early phases, but not clearly. OCTA, however, gave visualization of the vascular network and very precisely defined the vessels of the whole lesion, except for the pupillary portion, which was masked by superficial pigment accumulations. IFA and iris OCTA can add information about the vascular architecture compared to slit-lamp biomicroscopy, ultrasound biomicroscopy, and anterior-segment OCT. However, IFA is time-consuming and invasive and can – very occasionally – cause serious adverse reactions. In contrast, OCTA defines the texture of the iris vasculature better. In conclusion, OCTA is a new method, easy to execute, needing no dye injection, and provides useful information on the vascular network of iris lesions. It could therefore be helpful in the diagnosis and follow-up of these lesions. PMID:27790134

  3. [Placental 3D Doppler angiography: current and upcoming applications].

    PubMed

    Duan, J; Perdriolle-Galet, E; Chabot-Lecoanet, A-C; Callec, R; Beaumont, M; Chavatte-Palmer, P; Tsatsaris, V; Morel, O

    2015-02-01

    The placental dysfunction, which seems to be caused by a defect of trophoblastic invasion and impaired uterine vascular remodeling since the first trimester, is responsible in a non-exclusive way for the chronic placental hypoxia, resulting secondarily in the intra-uterine growth restriction (IUGR) and/or pre-eclampsia (PE). The quality of utero-placental vasculature is essential for a proper fetal development and a successful progress of pregnancy. However, the in vivo assessment of placental vascularization with non-invasive methods is complicated by the small size of placental terminal vessel and its complex architecture. Moreover, imaging with contrast agent is not recommended to pregnant women. Until recently, the fetal and maternal vascularization could only be evaluated through pulse Doppler of uterine arteries during pregnancy, which has little clinical value for utero-placental vascularization defects assessment. Recently, a non-invasive study, without use of contrast agent for vasculature evaluation of an organ of interest has become possible by the development of 3D Doppler angiography technique. The objective of this review was to make an inventory of its current and future applications for utero-placental vasculature quantification. The main findings of the literature on the assessment of utero-placental vascularization in physiological situation and major placental vascular dysfunction pathologies such as PE and IUGR were widely discussed.

  4. MD CT Angiography and MR Angiography of Nonatherosclerotic Renal Artery Disease

    SciTech Connect

    Flors, Lucia; Leiva-Salinas, Carlos; Ahmad, Ehab Ali; Norton, Patrick T.; Turba, Ulku C.; Bozlar, Ugur; Hagspiel, Klaus D.

    2011-12-15

    We reviewed the computed tomographic and magnetic resonance angiographic appearances of the various nonatherosclerotic renal artery pathologies. Rapid progress in cross-sectional techniques has allowed computed tomography and magnetic resonance angiography to replace digital subtraction angiography in most circumstances. When state-of-the-art equipment and optimized protocols are used, diagnosing a wide range of nonatherosclerotic pathologies is possible.

  5. Good visibility of TITAN-2 coronary stents demonstrable on cardiac computer tomographic angiography: a report of 2 cases.

    PubMed

    Ong, Paul Jau; Jau, Ong Paul; Ho, Hee Hwa; Hwa, Ho Hee; Jafary, Fahim Haider; Haider, Jafary Fahim; Loh, Kwok Kong; Kong, Loh Kwok; Ooi, Yau Wei; Wei, Ooi Yau; Wong, Chun Pong; Pong, Wong Chun; Foo, David; David, Foo

    2011-09-01

    Numerous studies have sought to assess stent patency by cardiac computer tomographic angiography (CCTA) in comparison with invasive coronary angiography in patients who had undergone percutaneous coronary stenting. Even with newer generation scanners, CCTA has been of limited value in the assessment of the revascularized patient. The main reason being blooming artifact from metallic stents often obscures stent luminal dimension, making the stented segment unassessable. We report on a novel finding of good visibility of TITAN-2 coronary stents demonstrable on CCTA for 2 patients and discuss the possible mechanism and potential implications of this observation.

  6. Investigating Invasives

    ERIC Educational Resources Information Center

    Lightbody, Mary

    2008-01-01

    Invasive species, commonly known as "invasives," are nonnative plants, animals, and microbes that completely take over and change an established ecosystem. The consequences of invasives' spread are significant. In fact, many of the species that appear on the Endangered Species list are threatened by invasives. Therefore, the topic of invasive…

  7. Transient cortical blindness after coronary angiography.

    PubMed

    Alp, B N; Bozbuğa, N; Tuncer, M A; Yakut, C

    2009-01-01

    Transient cortical blindness is rarely encountered after angiography of native coronary arteries or bypass grafts. This paper reports a case of transient cortical blindness that occurred 72 h after coronary angiography in a 56-year old patient. This was the patient's fourth exposure to contrast medium. Neurological examination demonstrated cortical blindness and the absence of any focal neurological deficit. A non-contrast-enhanced computed tomographic scan of the brain revealed bilateral contrast enhancement in the occipital lobes and no evidence of cerebral haemorrhage, and magnetic resonance imaging of the brain showed no pathology. Sight returned spontaneously within 4 days and his vision gradually improved. A search of the current literature for reported cases of transient cortical blindness suggested that this is a rarely encountered complication of coronary angiography.

  8. Full-field optical micro-angiography

    NASA Astrophysics Data System (ADS)

    Wang, Mingyi; Zeng, Yaguang; Liang, Xianjun; Lu, Xuanlong; Feng, Guanping; Han, Dingan; Yang, Guojian

    2014-02-01

    We present a detailed description of full-field optical micro-angiography on the basis of frequency-domain laser speckle imaging with intensity fluctuation modulation (LSI-IFM). The imaging approach works based on the instantaneous local intensity fluctuation realized via the combination of short exposure and low sampling rate of a camera and appropriate magnification of a microscope. In vivo experiments on mouse ear verify the theoretical description we made for the imaging mechanism and demonstrate the ability of LSI-IFM as optical micro-angiography. By introducing a fundus camera into LSI-IFM system, our approach has a potential application in label-free retina optical micro-angiography.

  9. Learning-based automatic detection of severe coronary stenoses in CT angiographies

    NASA Astrophysics Data System (ADS)

    Melki, Imen; Cardon, Cyril; Gogin, Nicolas; Talbot, Hugues; Najman, Laurent

    2014-03-01

    3D cardiac computed tomography angiography (CCTA) is becoming a standard routine for non-invasive heart diseases diagnosis. Thanks to its high negative predictive value, CCTA is increasingly used to decide whether or not the patient should be considered for invasive angiography. However, an accurate assessment of cardiac lesions using this modality is still a time consuming task and needs a high degree of clinical expertise. Thus, providing automatic tool to assist clinicians during the diagnosis task is highly desirable. In this work, we propose a fully automatic approach for accurate severe cardiac stenoses detection. Our algorithm uses the Random Forest classi cation to detect stenotic areas. First, the classi er is trained on 18 CT cardiac exams with CTA reference standard. Then, then classi cation result is used to detect severe stenoses (with a narrowing degree higher than 50%) in a 30 cardiac CT exam database. Features that best captures the di erent stenoses con guration are extracted along the vessel centerlines at di erent scales. To ensure the accuracy against the vessel direction and scale changes, we extract features inside cylindrical patterns with variable directions and radii. Thus, we make sure that the ROIs contains only the vessel walls. The algorithm is evaluated using the Rotterdam Coronary Artery Stenoses Detection and Quantication Evaluation Framework. The evaluation is performed using reference standard quanti cations obtained from quantitative coronary angiography (QCA) and consensus reading of CTA. The obtained results show that we can reliably detect severe stenosis with a sensitivity of 64%.

  10. Digital subtraction angiography of the thoracic aorta

    SciTech Connect

    Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.

    1984-02-01

    Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.

  11. Digital subtraction angiography of the kidney.

    PubMed

    Gattoni, F; Avogadro, A; Baldini, U; Pozzato, C; Bonfanti, M T; Gandini, D; Franch, L; Uslenghi, C

    1988-09-01

    Intravenous and intra-arterial digital subtraction angiography (DSA) was performed in 88 patients: 34 with tumours, 10 with renal trauma, 26 with suspected renovascular hypertension, 6 with vascular impression on the renal pelvis, 8 with nephrolithiasis and 4 with sonographically abnormal kidneys. Venous and arterial DSA always gave diagnostically useful images. Intravenous DSA is valuable in patients with suspected renovascular hypertension or after vascular surgery, percutaneous transluminal angioplasty and transcatheter embolisation. Arterial DSA is preferable to venous DSA in other clinical situations, particularly in the evaluation of renal tumours, and may be recommended in preference to conventional angiography.

  12. Innovations in imaging for chronic total occlusions: a glimpse into the future of angiography's blind-spot.

    PubMed

    Courtney, Brian K; Munce, Nigel R; Anderson, Kevan J; Thind, Amandeep S; Leung, General; Radau, Perry E; Foster, F Stuart; Vitkin, I Alex; Schwartz, Robert S; Dick, Alexander J; Wright, Graham A; Strauss, Bradley H

    2008-03-01

    Chronic total occlusions (CTOs) are a subset of lesions that present a considerable burden to cardiovascular patients. There exists a strong clinical desire to improve non-surgical options for CTO revascularization. While several techniques, devices, and guide wires have been developed and refined for use in CTOs, the inability of angiography to adequately visualize occluded arterial segments makes interventions in this setting technically challenging. This review describes the current status of several invasive and non-invasive imaging techniques that may facilitate improved image guidance during CTO revascularization, with the goals of improving procedure safety and efficacy while reducing the time required to complete these interventions. Cardiac imaging also has important potential roles in selecting patients most likely to benefit from revascularization as well as pre-procedural planning, post-procedural assessment of revascularized segments and long-term outcomes studies. Modalities discussed include non-invasive techniques, such as CT(computed tomography) angiography and cardiac magnetic resonance imaging (MRI), as well as invasive techniques, such as intravascular ultrasound, optical coherence tomography, intravascular MRI, and conventional angiography. While some of these techniques have some evidence to support their use at present, others are at earlier stages of development. Strategies that combine imaging techniques with the use of interventional therapies may provide significant opportunities to improve results in CTO interventions and represent an active area of investigation.

  13. Contrast enhanced ultrasonography versus MR angiography in aortocaval fistula: case report.

    PubMed

    Bhatia, Mona; Platon, Alexandra; Khabiri, Ebrahim; Becker, Christoph; Poletti, Pierre-Alexandre

    2010-06-01

    Aortocaval fistula (ACF) is a rare, life threatening complication of abdominal aortic aneurysms. Time to diagnosis is crucial as preoperative diagnosis and early surgical intervention significantly improve the outcome. The clinical spectrum being varied, the challenge of prompt and reliable diagnosis rests on emergency radiology. While the gold standard for detecting ACF today is CT angiography (CTA), frequently complicating renal insufficiency discourages the use of iodinated contrast making MR angiography (MRA) a useful alternative. Contrast enhanced ultrasound (CEUS) provides a promising new diagnostic option allowing rapid, non invasive and bedside diagnosis, especially in hemodynamically unstable patients. We present a case of prompt diagnosis of ACF by CEUS in comparison to modern MRA, thus establishing the new potential role of CEUS.

  14. Noninvasive Imaging of Atherosclerotic Plaque Progression: Status of Coronary CT Angiography

    PubMed Central

    Sandfort, Veit; Lima, Joao A.C.; Bluemke, David A.

    2015-01-01

    The process of coronary artery disease progression is infrequently visualized. Intravascular ultrasound has been used to gain important insights but is invasive and therefore limited to high risk patients. For low to moderate risk patients, noninvasive methods may be useful to quantitatively monitor plaque progression or regression, and to understand and personalize atherosclerosis therapy. This review discusses the potential for coronary CT angiography (CCTA) to evaluate the extent and subtypes of coronary plaque. CT technology is evolving and image quality of the method approaches the level required for plaque progression monitoring. Methods to quantify plaque on CT angiography are reviewed as well as a discussion of their use in clinical trials. Limitations of CCTA compared to competing modalities include limited evaluation of plaque subcomponents and incomplete knowledge of the value of the method especially in patients with low to moderate cardiovascular risk. PMID:26156016

  15. Follow-up of true visceral artery aneurysm after coil embolization by three-dimensional contrast-enhanced MR angiography

    PubMed Central

    Koganemaru, Masamichi; Abe, Toshi; Nonoshita, Masaaki; Iwamoto, Ryoji; Kusumoto, Masashi; Kuhara, Asako; Kugiyama, Tomoko

    2014-01-01

    PURPOSE We aimed to evaluate the outcomes of coil embolization of true visceral artery aneurysms by three-dimensional contrast-enhanced magnetic resonance (MR) angiography. MATERIALS AND METHODS We used three-dimensional contrast-enhanced MR angiography, which included source images, to evaluate 23 patients (mean age, 60 years; range, 28–83 years) with true visceral artery aneurysms (splenic, n=15; hepatic, n=2; gastroduodenal, n=2; celiac, n=2; pancreaticoduodenal, n=1; gastroepiploic, n=1) who underwent coil embolization. Angiographic aneurysmal occlusion was revealed in all cases. Follow-up MR angiography was conducted with either a 1.5 or 3 Tesla system 3–25 months (mean, 18 months) after embolization. MR angiography was evaluated for aneurysmal occlusion, hemodynamic status, and complications. RESULTS Complete aneurysmal occlusion was determined in 22 patients (96%) on follow-up MR angiography (mean follow-up period, 18 months). Neck recanalization, which was observed at nine and 20 months after embolization, was confirmed in one of eight patients (13%) using a neck preservation technique. In this patient, a small neck recanalization covered by a coil mass was demonstrated. The complete hemodynamic status after embolization was determined in 21 patients (91%); the visualization of several collateral vessels, such as short gastric arteries, after parent artery occlusion was poor compared with that seen on digital subtraction angiography in the remaining two patients (9%). An asymptomatic localized splenic infarction was confirmed in one patient (4%). CONCLUSION Our study presents the follow-up results from three-dimensional contrast-enhanced MR angiography, which confirmed neck recanalization, the approximate hemodynamic status, and complications. This effective and less invasive method may be suitable for serial follow-up after coil embolization of true visceral aneurysms. PMID:24356294

  16. Preserved Coronary Flow Reserve Effectively Excludes High-Risk Coronary Artery Disease on Angiography

    PubMed Central

    Naya, Masanao; Murthy, Venkatesh L.; Taqueti, Viviany R.; Foster, Courtney R.; Klein, Josh; Garber, Mariya; Dorbala, Sharmila; Hainer, Jon; Blankstein, Ron; Resnic, Frederick; Di Carli, Marcelo F.

    2014-01-01

    Myocardial perfusion imaging has limited sensitivity for the detection of high-risk coronary artery disease (CAD). We tested the hypothesis that a normal coronary flow reserve (CFR) would be helpful for excluding the presence of high-risk CAD on angiography. Methods We studied 290 consecutive patients undergoing 82Rb PET within 180 d of invasive coronary angiography. High-risk CAD on angiography was defined as 2-vessel disease (≥70% stenosis), including the proximal left anterior descending artery; 3-vessel disease; or left main CAD (≥50% stenosis). Patients with prior Q wave myocardial infarction, elevated troponin levels between studies, prior coronary artery bypass grafting, a left ventricular ejection fraction of less than 40%, or severe valvular heart disease were excluded. Results Fifty-five patients (19%) had high-risk CAD on angiography. As expected, the trade-off between the sensitivity and the specificity of the CFR for identifying high-risk CAD varied substantially depending on the cutoff selected. In multivariable analysis, a binary CFR of less than or equal to 1.93 provided incremental diagnostic information for the identification of high-risk CAD beyond the model with the Duke clinical risk score (>25%), percentage of left ventricular ischemia (>10%), transient ischemic dilation index (>1.07), and change in the left ventricular ejection fraction during stress (<2) (P = 0.0009). In patients with normal or slightly to moderately abnormal results on perfusion scans (<10% of left ventricular mass) during stress (n = 136), a preserved CFR (>1.93) excluded high-risk CAD with a high sensitivity (86%) and a high negative predictive value (97%). Conclusion A normal CFR has a high negative predictive value for excluding high-risk CAD on angiography. Although an abnormal CFR increases the probability of significant obstructive CAD, it cannot reliably distinguish significant epicardial stenosis from nonobstructive, diffuse atherosclerosis or microvascular

  17. ICG angiography predicts burn scarring within 48 h of injury in a porcine vertical progression burn model.

    PubMed

    Fourman, Mitchell S; McKenna, Peter; Phillips, Brett T; Crawford, Laurie; Romanelli, Filippo; Lin, Fubao; McClain, Steve A; Khan, Sami U; Dagum, Alexander B; Singer, Adam J; Clark, Richard A F

    2015-08-01

    The current standard of care in determining the need to excise and graft a burn remains with the burn surgeon, whose clinical judgment is often variable. Prior work suggests that minimally invasive perfusion technologies are useful in burn prognostication. Here we test the predictive capabilities of Laser Doppler Imaging (LDI) and indocyanine green dye (ICG) angiography in the prediction of burn scarring 28 days after injury using a previously validated porcine burn model that shows vertical progression injury. Twelve female Yorkshire swine were burned using a 2.5 × 2.5 cm metal bar at variable temperature and application times to create distinct burn depths. Six animals (48 injuries total) each were analyzed with LDI or ICG angiography at 1, 24, 48, and 72 h following injury. A linear regression was then performed correlating perfusion measurements against wound contraction at 28 days after injury. ICG angiography showed a peak linear correlate (r(2)) of .63 (95% CI .34 to .92) at 48 h after burn. This was significantly different from the LDI linear regression (p < .05), which was measured at r(2) of .20 (95% CI .02 to .39). ICG angiography linear regression was superior to LDI at all timepoints. Findings suggest that ICG angiography may have significant potential in the prediction of long-term burn outcomes.

  18. Invasive Species

    EPA Pesticide Factsheets

    Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

  19. Invasive Candidiasis

    MedlinePlus

    ... Invasive candidiasis is an infection caused by a yeast (a type of fungus) called Candida . Unlike Candida ... mouth and throat (also called “thrush”) or vaginal “yeast infections,” invasive candidiasis is a serious infection that ...

  20. Performance of magnetic resonance angiography in suspected acute pulmonary embolism.

    PubMed

    Blum, Alain; Bellou, Abdelouahab; Guillemin, Francis; Douek, Philippe; Laprévote-Heully, Marie-Claude; Wahl, Denis

    2005-03-01

    Pulmonary embolism (PE) is a common and potentially fatal disorder. Non-specific findings make the clinical diagnosis of PE difficult. To assess the diagnostic value and inter-observer agreement of magnetic resonance angiography (MRA) in a cohort of patients with suspected PE, we conducted a prospective clinical study. MRA was compared for sensitivity and specificity to a diagnostic strategy including clinical probability, D-dimer testing, spiral CT, ultrasound leg compression and pulmonary angiography. A total of 89 patients with clinically suspected PE were included: the clinical probability of PE was intermediate or high in 78, and low in the remaining 11. All patients underwent monoor multi-slice spiral CT and MRA with gadolinium injection (both within 24 hours of entry to the study). Anticoagulation was withheld in patients concerned about the strategy. All subjects were followed up for 3 months. MRA was read independently by two experienced teams of radiologists: one local and one from another university centre. Spiral CT was positive in 62 of 63 cases of confirmed PE. No patient with negative CT findings was positive ultrasonographically. Only one patient with a negative CT (and negative ultrasound) had a recurrent thromboembolic event. The first team diagnosed PE with MRA in 47 cases, with a sensitivity of 71% and a specificity of 92%; the second team obtained the diagnosis in 23 cases, with a sensitivity of 31% and a specificity of 85%. Inter-observer agreement between MRA reading was low: Kappa = 0.16 (-0.01 to 0.33); p = 0.07. In conclusion, compared with a non-invasive strategy based on spiral CT, the diagnostic value of MRA is limited by poor inter-observer agreement.

  1. Unexpected Angiography Findings and Effects on Management

    PubMed Central

    Neill, Matthew; Charles, Hearns W; Gross, Jonathan S; Farquharson, Sean; Deipolyi, Amy R

    2016-01-01

    Despite progress in noninvasive imaging with computed tomography and magnetic resonance imaging, conventional angiography still contributes to the diagnostic workup of oncologic and other diseases. Arteriography can reveal tumors not evident on cross-sectional imaging, in addition to defining aberrant or unexpected arterial supply to targeted lesions. This additional and potentially unanticipated information can alter management decisions during interventional procedures. PMID:27688932

  2. [MRI angiography of the thoracic vessels including coronary arteries: techniques and indications].

    PubMed

    Didier, D

    1999-09-01

    Because it is a non-invasive method, Magnetic Resonance Angiography has more and more indications in the thorax, particularly with the help of use of contrast media. Different types of sequences used (Cine-MR, Gradient-echo 2D and Gadolinium enhanced breath-hold and non breath-hold 3D) are described as well as acquisition parameters and reconstructions from natives images. Post-processing techniques (MIP, MPR, 3D Surface Rendering) and their limitations depending upon the region explored are explained. Major indications (congenital anomalies of the great vessels, aneurysms, dissections, post-operative studies, evaluation of coronary arteries) are illustrated and the role of MRA compared to the other invasive and non invasive modalities is discussed.

  3. Patients with Life-Threatening Arterial Renal Hemorrhage: CT Angiography and Catheter Angiography with Subsequent Superselective Embolization

    SciTech Connect

    Sommer, C. M. Stampfl, U.; Bellemann, N.; Ramsauer, S.; Loenard, B. M.; Haferkamp, A.; Hallscheidt, P.; Richter, G. M.; Kauczor, H. U.; Radeleff, B. A.

    2010-06-15

    The purpose of this study was to evaluate the technical and clinical success of superselective embolization in patients with life-threatening arterial renal hemorrhage undergoing preinterventional CT angiography. Forty-three patients with clinical signs of life-threatening arterial renal hemorrhage underwent CT angiography and catheter angiography. Superselective embolization was indicated in the case of a positive catheter angiography. Primary study goals were technical and clinical success of superselective embolization. Secondary study goals were CT angiographic and catheter angiographic image findings and clinical follow-up. The mean time interval between CT angiography and catheter angiography was 8.3 {+-} 10.3 h (range, 0.2-34.1 h). Arterial renal hemorrhage was identified with CT angiography in 42 of 43 patients (98%) and catheter angiography in 39 of 43 patients (91%) (overview angiography in 4 of 43 patients [9%], selective angiography in 16 of 43 patients [37%], and superselective angiography in 39 of 43 patients [91%]). Superselective embolization was performed in 39 of 43 patients (91%) and technically successful in 37 of 39 patients (95%). Therefore, coil embolization was performed in 13 of 37 patients (35%), liquid embolization in 9 of 37 patients (24%), particulate embolization in 1 of 37 patients (3%), and a combination in 14 of 37 patients (38%). Clinical failure occurred in 8 of 39 patients (21%) and procedure-related complications in 2 of 39 patients (5%). The 30-day mortality rate was 3%. Hemoglobin decreased significantly prior to intervention (P < 0.001) and increased significantly after intervention (P < 0.005). In conclusion, superselective embolization is effective, reliable, and safe in patients with life-threatening arterial renal hemorrhage. In contrast to overview and selective angiography, only superselective angiography allows reliable detection of arterial renal hemorrhage. Preinterventional CT angiography is excellent for detection

  4. Gadofosveset-enhanced magnetic resonance angiography

    PubMed Central

    Goyen, Mathias

    2008-01-01

    Gadofosveset (Vasovist®, Bayer Schering Pharma AG, Berlin/Germany) is the first intravascular contrast agent approved for use with magnetic resonance angiography in the European Union, Switzerland, Turkey, Canada, and Australia. Gadofosveset reversibly binds to albumin providing extended intravascular enhancement compared wth existing extracellular magnetic resonance contrast agents. Prior to approval, gadofosveset underwent extensive testing to evaluate the safety and efficacy of the drug; the clinical trials show that gadofosveset-enhanced magnetic resonance angiography (MRA) is safe and well tolerated in patients with vascular disease and effective for the detection of vascular stenosis and aneurysms gadofosveset has the potential to open new horizons in diagnostic MRA by increasing the spatial resolution and the robustness of MRA examinations and facilitating the examination of multiple vascular beds. PMID:18629367

  5. Angiography of Liver Transplantation Patients 1

    PubMed Central

    Zajko, Albert B.; Bron, Klaus M.; Starzl, Thomas E.; Van Thiel, David H.; Gartner, J. Carlton; Iwatsuki, Shunzaburo; Shaw, Byers W.; Zitelli, Basil J.; Malatack, J. Jeffrey; Urbach, Andrew H.

    2010-01-01

    Over 45 months, 119 angiographic examinations were performed in 95 patients prior to liver transplantation, and 53 examinations in 44 patients after transplantation. Transplantation feasibility was influenced by patency of the portal vein and inferior vena cava. Selective arterial portography, wedged hepatic venography, and transhepatic portography were used to assess the portal vein if sonography or computed tomography was inconclusive. Major indications for angiography after transplantation included early liver failure, sepsis, unexplained elevation of liver enzyme levels, and delayed bile leakage, all of which may be due to hepatic artery thrombosis. Other indications included gastrointestinal tract bleeding, hemobilia, and evaluation of portal vein patency in patients with chronic rejection who were being considered for retransplantation. Normal radiographic features of hepatic artery and portal vein reconstruction are demonstrated. Complications diagnosed using results of angiography included hepatic artery or portal vein stenoses and thromboses and pancreaticoduodenal aneurysms. Intrahepatic arterial narrowing, attenuation, slow flow, and poor filling were seen in five patients with rejection PMID:3901102

  6. Types of diaphragmatic motion during hepatic angiography.

    PubMed

    Katsuda, T; Kuroda, C; Fujita, M

    1997-01-01

    To determine the types and causes of diaphragmatic motion during hepatic angiography, the authors used transarterial cut-film portography (TAP) to study movement of the diaphragm during breath-holding. Thirty-three TAP sequences were studied, and the patients' diaphragmatic motions were classified into four categories according to the distance their diaphragms moved. Results showed that the diaphragm was stationary in 33% of the TAP studies, while perpetual motion occurred in 15% of the studies, early-phase motion occurred in 12% and late-phase motion occurred in 40%. Ten sequences showed diaphragmatic motion of more than 10 mm, with eight sequences showing caudal motion and two showing cranial motion. This article discusses the cause of diaphragmatic motion during breath-holding for hepatic angiography and presents suggestions to reduce motion artifacts during the exam.

  7. Cardiac CT Angiography in Congestive Heart Failure.

    PubMed

    Levine, Avi; Hecht, Harvey S

    2015-06-01

    Cardiac CT angiography has become an important tool for the diagnosis and treatment of congestive heart failure. Differentiation of ischemic from nonischemic cardiomyopathy; evaluation of myocardial perfusion; characterization of hypertrophic cardiomyopathy, left ventricular noncompaction, and arrhythmogenic right ventricular dysplasia; and delineation of congenital heart defects and valvular abnormalities are the primary diagnostic applications. Therapeutic use includes visualization of the coronary venous anatomy for optimal implementation of cardiac resynchronization therapy and evaluation of left ventricular assist devices and transplant vasculopathy.

  8. Indocyanine green angiography features of malattia leventinese

    PubMed Central

    Souied, E H; Leveziel, N; Querques, G; Darmon, J; Coscas, G; Soubrane, G

    2006-01-01

    Background/aim Malattia leventinese (ML) is an inherited macular degeneration characterised by the presence of small radial drusen. Despite extensive descriptions of this study of the fundus, angiographic features of ML have been inadequately described. The aim is to describe the indocyanine green angiography (ICG) features observed in ML. Methods 10 eyes from five consecutive ML patients (aged 27–44 years) were prospectively included. A complete ophthalmological examination including colour fundus photographs, autofluorescence, fluorescein angiography (FA), and ICG was performed. Results ICG differentiated two types of drusen. Large round aggregated drusen were consistently hypofluorescent in the early phases and presented as hyperfluorescent spots surrounded by halos of hypofluorescence in the late phases. Conversely, small radial drusen were mostly hyperfluorescent in the early phases with decreased fluorescence in the late phases of the ICG sequence. FA also showed differences in staining between the two types of drusen. Conclusions ICG angiography revealed marked differences between the large round and small radial drusen observed in ML. The large central drusen presented with an unusual pustuliform feature on the late phases of the ICG sequence. This distinct feature may be useful in the diagnosis of late stage disease when drusen consolidation could obscure the radial drusen. PMID:16488948

  9. Acute chest pain: the role of MR imaging and MR angiography.

    PubMed

    Hunold, Peter; Bischoff, Peter; Barkhausen, Jörg; Vogt, Florian M

    2012-12-01

    MR imaging (MRI) and MR angiography (MRA) have gained a high level of diagnostic accuracy in cardiovascular disease. MRI in cardiac disease has been established as the non-invasive standard of reference in many pathologies. However, in acute chest pain the situation is somewhat special since many of the patients presenting in the emergency department suffer from potentially life-threatening disease including acute coronary syndrome, pulmonary embolism, and acute aortic syndrome. Those patients need a fast and definitive evaluation under continuous monitoring of vital parameters. Due to those requirements MRI seems to be less suitable compared to X-ray coronary angiography and multislice computed tomography angiography (CTA). However, MRI allows for a comprehensive assessment of all clinically stable patients providing unique information on the cardiovascular system including ischemia, inflammation and function. Furthermore, MRI and MRA are considered the method of choice in patients with contraindications to CTA and for regular follow-up in known aortic disease. This review addresses specific features of MRI and MRA for different cardiovascular conditions presenting with acute chest pain.

  10. A Randomized-Controlled Trial Examining the Effects of Reflexology on Anxiety of Patients Undergoing Coronary Angiography

    PubMed Central

    Molavi Vardanjani, Mehdi; Masoudi Alavi, Negin; Razavi, Narges Sadat; Aghajani, Mohammad; Azizi-Fini, Esmail; Vaghefi, Seied Morteza

    2013-01-01

    Background: The anxiety reduction before coronary angiography has clinical advantages and is one of the objectives of nursing. Reflexology is a non-invasive method that has been used in several clinical situations. Applying reflexology might have effect on the reduction of anxiety before coronary angiography. Objectives: The aim of this randomized clinical trial was to investigate the effect of reflexology on anxiety among patients undergoing coronary angiography. Patients and Methods: This trial was conducted in Shahid Beheshti Hospital, in Kashan, Iran. One hundred male patients who were undergoing coronary angiography were randomly enrolled into intervention and placebo groups. The intervention protocol was included 30 minutes of general foot massage and the stimulation of three reflex points including solar plexus, pituitary gland, and heart. The placebo group only received the general foot massage. Spielbergers state trait anxiety inventory was used to assess the anxiety experienced by patients. Data was analyzed using Man-Witney, Wilcoxon and Chi-square tests. The stepwise multiple regressions used to analyze the variables that are involved in anxiety reduction. Results: The mean range of anxiety decreased from 53.24 to 45.24 in reflexology group which represented 8 score reduction (P = 0.0001). The reduction in anxiety was 5.9 score in placebo group which was also significant (P = 0.0001). The anxiety reduction was significantly higher in reflexology group (P = 0.014). The stepwise multiple regression analysis showed that doing reflexology can explain the 7.5% of anxiety reduction which made a significant model. Conclusions: Reflexology can decrease the anxiety level before coronary angiography. Therefore, reflexology before coronary angiography is recommended. PMID:25414869

  11. Diagnostic yield and accuracy of CT angiography, MR angiography, and digital subtraction angiography for detection of macrovascular causes of intracerebral haemorrhage: prospective, multicentre cohort study

    PubMed Central

    Velthuis, Birgitta K; Rinkel, Gabriël J E; Algra, Ale; de Kort, Gérard A P; Witkamp, Theo D; de Ridder, Johanna C M; van Nieuwenhuizen, Koen M; de Leeuw, Frank-Erik; Schonewille, Wouter J; de Kort, Paul L M; Dippel, Diederik W; Raaymakers, Theodora W M; Hofmeijer, Jeannette; Wermer, Marieke J H; Kerkhoff, Henk; Jellema, Korné; Bronner, Irene M; Remmers, Michel J M; Bienfait, Henri Paul; Witjes, Ron J G M; Greving, Jacoba P; Klijn, Catharina J M

    2015-01-01

    Study question What are the diagnostic yield and accuracy of early computed tomography (CT) angiography followed by magnetic resonance imaging/angiography (MRI/MRA) and digital subtraction angiography (DSA) in patients with non-traumatic intracerebral haemorrhage? Methods This prospective diagnostic study enrolled 298 adults (18-70 years) treated in 22 hospitals in the Netherlands over six years. CT angiography was performed within seven days of haemorrhage. If the result was negative, MRI/MRA was performed four to eight weeks later. DSA was performed when the CT angiography or MRI/MRA results were inconclusive or negative. The main outcome was a macrovascular cause, including arteriovenous malformation, aneurysm, dural arteriovenous fistula, and cavernoma. Three blinded neuroradiologists independently evaluated the images for macrovascular causes of haemorrhage. The reference standard was the best available evidence from all findings during one year’s follow-up. Study answer and limitations A macrovascular cause was identified in 69 patients (23%). 291 patients (98%) underwent CT angiography; 214 with a negative result underwent additional MRI/MRA and 97 with a negative result for both CT angiography and MRI/MRA underwent DSA. Early CT angiography detected 51 macrovascular causes (yield 17%, 95% confidence interval 13% to 22%). CT angiography with MRI/MRA identified two additional macrovascular causes (18%, 14% to 23%) and these modalities combined with DSA another 15 (23%, 18% to 28%). This last extensive strategy failed to detect a cavernoma, which was identified on MRI during follow-up (reference strategy). The positive predictive value of CT angiography was 72% (60% to 82%), of additional MRI/MRA was 35% (14% to 62%), and of additional DSA was 100% (75% to 100%). None of the patients experienced complications with CT angiography or MRI/MRA; 0.6% of patients who underwent DSA experienced permanent sequelae. Not all patients with negative CT angiography and

  12. Perceptual enhancement of arteriovenous malformation in MRI angiography displays

    NASA Astrophysics Data System (ADS)

    Abhari, Kamyar; Baxter, John S. H.; Eagleson, Roy; Peters, Terry; de Ribaupierre, Sandrine

    2012-02-01

    The importance of presenting medical images in an intuitive and usable manner during a procedure is essential. However, most medical visualization interfaces, particularly those designed for minimally-invasive surgery, suffer from a number of issues as a consequence of disregarding the human perceptual, cognitive, and motor system's limitations. This matter is even more prominent when human visual system is overlooked during the design cycle. One example is the visualization of the neuro-vascular structures in MR angiography (MRA) images. This study investigates perceptual performance in the usability of a display to visualize blood vessels in MRA volumes using a contour enhancement technique. Our results show that when contours are enhanced, our participants, in general, can perform faster with higher level of accuracy when judging the connectivity of different vessels. One clinical outcome of such perceptual enhancement is improvement of spatial reasoning needed for planning complex neuro-vascular operations such as treating Arteriovenous Malformations (AVMs). The success of an AVM intervention greatly depends on fully understanding the anatomy of vascular structures. However, poor visualization of pre-operative MRA images makes the planning of such a treatment quite challenging.

  13. Changes in Medical Management after Coronary CT Angiography

    PubMed Central

    Naue, Vânia Mairi; Camargo, Gabriel; Sabioni, Letícia Roberto; Lima, Ronaldo de Souza Leão; Derenne, Maria Eduarda; de Lorenzo, Andréa Rocha; Freire, Monica Di Calafiori; Azevedo Filho, Clério Francisco; Resende, Elmiro Santos; Gottlieb, Ilan

    2015-01-01

    Introduction Coronary computed tomography angiography (CCTA) allows for non-invasive coronary artery disease (CAD) phenotyping. There are still some uncertainties regarding the impact this knowledge has on the clinical care of patients. Objective To determine whether CAD phenotyping by CCTA influences clinical decision making by the prescription of cardiovascular drugs and their impact on non-LDL cholesterol (NLDLC) levels. Methods We analysed consecutive patients from 2008 to 2011 submitted to CCTA without previous diagnosis of CAD that had two serial measures of NLDLC, one up to 3 months before CCTA and the second from 3 to 6 months after. Results A total of 97 patients were included, of which 69% were men, mean age 64 ± 12 years. CCTA revealed that 18 (18%) patients had no CAD, 38 (39%) had non-obstructive (< 50%) lesions and 41 (42%) had at least one obstructive ≥ 50% lesion. NLDLC was similar at baseline between the grups (138 ± 52 mg/dL vs. 135 ± 42 mg/dL vs. 131 ± 44 mg/dL, respectively, p = 0.32). We found significative reduction in NLDLC among patients with obstrctive lesions (-18%, p = 0.001). We also found a positive relationship between clinical treatment intensification with aspirin and cholesterol reducing drugs and the severity of CAD. Conclusion Our data suggest that CCTA results were used for cardiovascular clinical treatment titration, with especial intensification seen in patients with obstructive ≥50% CAD. PMID:26559988

  14. Comparison and co-relation of invasive and noninvasive methods of ejection fraction measurement.

    PubMed Central

    Godkar, Darshan; Bachu, Kalyan; Dave, Bijal; Megna, Robert; Niranjan, Selva; Khanna, Ashok

    2007-01-01

    BACKGROUND: Accurate estimation of left ventricular ejection fraction (LVEF) has assumed great significance in the era of automatic implantable cardioverter defibrillators (AICDs), and a low EF may be one of the sole deciding factor in determining AICD implantation in certain patient populations. AIM: There are various methods, invasive and noninvasive, which can help calculate EF. We sought to conduct a retrospective study comparing EF estimation by invasive (angiography) and noninvasive methods [MUGA (multiple-gated acquisition), echocardiography (echo), single-photon emission computed tomography (SPECT)] in 5,558 patients in our hospital from 1995-2004. METHODS AND RESULTS: EF was estimated by > or = 1 method (angiography, MUGA, echo, SPECT) within a one-month period. Values for the four tests in 5,558 patients were as follows: angiography mean 46.2, range 20-75, standard deviation (SD) 13.1; MUGA mean 45.7, range 20-70, SD 11.6; echo mean 45.7, range 22-70, SD 11.2; and SPECT mean 54.4, range 30-75, SD 11.9. Excellent positive correlations were found among all four tests as follows: angiography and MUGA, correlation coefficient (r) = 0.97, angiography and echo r = 0.96, angiography and SPECT r = 0.94, MUGA and echo r = 0.97, MUGA and SPECT r = 0.94, and echo and SPECT r = 0.94. Values for SPECT were significantly higher than for angiography, echo and MUGA (p < 0.001). The arithmetic difference between angiography and MUGA (mean 0.50, range -5.0-5.0) and the arithmetic difference between angiography and echo (mean 0.52, range -5.0-15.0) were similar (p = 0.59). The arithmetic difference between SPECT and angiography (mean 8.2, range -15.0-20.0) was significantly larger than the arithmetic difference between angiography and echo (p < 0.001). CONCLUSIONS: All the four methods used to estimate EF corelate well with each other. However, values estimated during stress testing by SPECT overestimate EF and are significantly higher as compared to MUGA, echo and

  15. Kinematics of Compton backscattering x-ray source for angiography

    SciTech Connect

    Blumberg, L.N.

    1992-05-01

    Calculations of X-Ray production rates, energy spread, and spectrum of Compton-backscattered photons from a Free Electron Laser on an electron beam in a low energy (136-MeV) compact (8.5-m circumference) storage ring indicate that an X-Ray intensity of 34.6 10{sup 7} X-Ray photons per 0.5-mm {times} 0.5-mm pixel for Coronary Angiography near the 33.169-keV iodine K-absorption edge can be achieved in a 4-msec pulse within a scattering cone of 1-mrad half angle. This intensity, at 10-m from the photon-electron interaction point to the patient is about a factor of 10 larger than presently achieved from a 4.5-T superconducting wiggler source in the NSLS 2.5-GeV storage ring and over an area about 5 times larger. The 2.2-keV energy spread of the Compton-backscattered beam is, however, much larger than the 70-eV spread presently attained form the wiggler source and use of a monochromator. The beam spot at the 10-m interaction point-to-patient distance is 20-mm diameter; larger spots are attainable at larger distances but with a corresponding reduction in X-Ray flux. Such a facility could be an inexpensive clinical alternative to present methods of non-invasive Digital Subtraction Angiography (DSA), small enough to be deployed in an urban medical center, and could have other medical, industrial and aerospace applications. Problems with the Compton backscattering source include laser beam heating of the mirror in the FEL oscillator optical cavity, achieving a large enough X-Ray beam spot at the patient, and obtaining radiation damping of the transverse oscillations and longitudinal emittance dilution of the storage ring electron beam resulting from photon-electron collisions without going to higher electron energy where the X-Ray energy spread becomes excessive for DSA. 38 refs.

  16. Computed Tomographic Angiography of the Abdominal Aorta.

    PubMed

    Hansen, Neil J

    2016-01-01

    Computed tomographic (CT) angiography (CTA) has become the preferred imaging test of choice for various aortic conditions because of its excellent spatial resolution, rapid image acquisition, and its wide availability. CTA provides a robust tool for planning aortic interventions and diagnosing acute and chronic vascular diseases in the abdomen. CTA is the standard for imaging aneurysms before intervention and evaluating the aorta in the acute setting to assess traumatic injury, dissection, and aneurysm rupture. Knowledge of the imaging features of these disease processes, inflammatory vasculitides, and occlusive atherosclerotic disease is essential for guiding surgical and medical management of patients.

  17. Hemodialysis fistula occlusion: demonstration with 64-slice CT angiography.

    PubMed

    Neyman, Edward G; Johnson, Pamela T; Fishman, Elliot K

    2006-01-01

    The speed and resolution of 64-slice CT have resulted in new applications for CT angiography (CTA) owing to rapid data acquisition during the arterial phase, improved visualization of small vessels, and lengthened anatomic coverage. Extremity CT angiography is one such region. This case report shows the utility of multislice CTA for the evaluation of hemodialysis graft dysfunction.

  18. Coronary CT angiography: Beyond morphological stenosis analysis.

    PubMed

    Sun, Zhonghua

    2013-12-26

    Rapid technological developments in computed tomography (CT) imaging technique have made coronary CT angiography an attractive imaging tool in the detection of coronary artery disease. Despite visualization of excellent anatomical details of the coronary lumen changes, coronary CT angiography does not provide hemodynamic changes caused by presence of plaques. Computational fluid dynamics (CFD) is a widely used method in the mechanical engineering field to solve complex problems through analysing fluid flow, heat transfer and associated phenomena by using computer simulations. In recent years, CFD is increasingly used in biomedical research due to high performance hardware and software. CFD techniques have been used to study cardiovascular hemodynamics through simulation tools to assist in predicting the behaviour of circulatory blood flow inside the human body. Blood flow plays a key role in the localization and progression of coronary artery disease. CFD simulation based on 3D luminal reconstructions can be used to analyse the local flow fields and flow profiling due to changes of vascular geometry, thus, identifying risk factors for development of coronary artery disease. The purpose of this article is to provide an overview of the coronary CT-derived CFD applications in coronary artery disease.

  19. Angiography with a multifunctional line scanning ophthalmoscope

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Ferguson, R. Daniel; Patel, Ankit H.; Vazquez, Vanessa; Husain, Deeba

    2012-02-01

    A multifunctional line scanning ophthalmoscope (mLSO) was designed, constructed, and tested on human subjects. The mLSO could sequentially acquire wide-field, confocal, near-infrared reflectance, fluorescein angiography (FA), and indocyanine green angiography (ICGA) retinal images. The system also included a retinal tracker (RT) and a photodynamic therapy laser treatment port. The mLSO was tested in a pilot clinical study on human subjects with and without retinal disease. The instrument exhibited robust retinal tracking and high-contrast line scanning imaging. The FA and ICGA angiograms showed a similar appearance of hyper- and hypo-pigmented disease features and a nearly equivalent resolution of fine capillaries compared to a commercial flood-illumination fundus imager. An mLSO-based platform will enable researchers and clinicians to image human and animal eyes with a variety of modalities and deliver therapeutic beams from a single automated interface. This approach has the potential to improve patient comfort and reduce imaging session times, allowing clinicians to better diagnose, plan, and conduct patient procedures with improved outcomes.

  20. Perfusion Angiography in Acute Ischemic Stroke

    PubMed Central

    Liebeskind, David S.

    2016-01-01

    Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and Tmax, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. PMID:27446232

  1. Feasibility and diagnostic performance of fractional flow reserve measurement derived from coronary computed tomography angiography in real clinical practice.

    PubMed

    Kawaji, Tetsuma; Shiomi, Hiroki; Morishita, Hiroshi; Morimoto, Takeshi; Taylor, Charles A; Kanao, Shotaro; Koizumi, Koji; Kozawa, Satoshi; Morihiro, Kazuhisa; Watanabe, Hirotoshi; Tazaki, Junichi; Imai, Masao; Saito, Naritatsu; Shizuta, Satoshi; Ono, Koh; Togashi, Kaori; Kimura, Takeshi

    2017-02-01

    Non-invasive fractional flow reserve measured by coronary computed tomography angiography (FFRCT) has demonstrated a high diagnostic accuracy for detecting coronary artery disease (CAD) in selected patients in prior clinical trials. However, feasibility of FFRCT in unselected population have not been fully evaluated. Among 60 consecutive patients who had suspected significant CAD by coronary computed tomography angiography (CCTA) and were planned to undergo invasive coronary angiography, 48 patients were enrolled in this study comparing FFRCT with invasive fractional flow reserve (FFR) without any exclusion criteria for the quality of CCTA image. FFRCT was measured in a blinded fashion by an independent core laboratory. FFRCT value was evaluable in 43 out of 48 (89.6 %) patients with high prevalence of severe calcification in CCTA images [calcium score (CS) >400: 40 %, and CS > 1000: 19 %). Per-vessel FFRCT value showed good correlation with invasive FFR value (Spearman's rank correlation = 0.69, P < 0.001). The area under the receiver operator characteristics curve (AUC) of FFRCT was 0.87. Per-vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 68.6, 92.9, 52.4, 56.5, and 91.7 %, respectively. Even in eight patients (13 vessels) with extremely severely calcified lesions (CS > 1000), per-vessel FFRCT value showed a diagnostic performance similar to that in patients with CS ≤ 1000 (Spearman's rank correlation = 0.81, P < 0.001). FFRCT could be measured in the majority of consecutive patients who had suspected significant CAD by CCTA in real clinical practice and demonstrated good diagnostic performance for detecting hemodynamically significant CAD even in patients with extremely severe calcified vessels.

  2. Gadolinium-Enhanced Magnetic Resonance Angiography for Pulmonary Embolism

    PubMed Central

    Stein, Paul D.; Chenevert, Thomas L.; Fowler, Sarah E.; Goodman, Lawrence R.; Gottschalk, Alexander; Hales, Charles A.; Hull, Russell D.; Jablonski, Kathleen A.; Leeper, Kenneth V.; Naidich, David P.; Sak, Daniel J.; Sostman, H. Dirk; Tapson, Victor F.; Weg, John G.; Woodard, Pamela K.

    2011-01-01

    Background The accuracy of gadolinium-enhanced magnetic resonance pulmonary angiography and magnetic resonance venography for diagnosing pulmonary embolism has not been determined conclusively. Objective To investigate performance characteristics of magnetic resonance angiography, with or without magnetic resonance venography, for diagnosing pulmonary embolism. Design Prospective, multicenter study from 10 April 2006 to 30 September 2008. (ClinicalTrials.gov registration number: NCT00241826) Setting 7 hospitals and their emergency services. Patients 371 adults with diagnosed or excluded pulmonary embolism. Measurements Sensitivity, specificity, and likelihood ratios were measured by comparing independently read magnetic resonance imaging with the reference standard for diagnosing pulmonary embolism. Reference standard diagnosis or exclusion was made by using various tests, including computed tomographic angiography and venography, ventilation–perfusion lung scan, venous ultra-sonography, D-dimer assay, and clinical assessment. Results Magnetic resonance angiography, averaged across centers, was technically inadequate in 25% of patients (92 of 371). The proportion of technically inadequate images ranged from 11% to 52% at various centers. Including patients with technically inadequate images, magnetic resonance angiography identified 57% (59 of 104) with pulmonary embolism. Technically adequate magnetic resonance angiography had a sensitivity of 78% and a specificity of 99%. Technically adequate magnetic resonance angiography and venography had a sensitivity of 92% and a specificity of 96%, but 52% of patients (194 of 370) had technically inadequate results. Limitation A high proportion of patients with suspected embolism was not eligible or declined to participate. Conclusion Magnetic resonance pulmonary angiography should be considered only at centers that routinely perform it well and only for patients for whom standard tests are contraindicated. Magnetic

  3. The Emerging Roles of Coronary Computed Tomographic Angiography: Acute Chest Pain Evaluation and Screening for Asymptomatic Individuals

    PubMed Central

    Chien, Ning; Wang, Tzung-Dau; Chang, Yeun-Chung; Lin, Po-Chih; Tseng, Yao-Hui; Lee, Yee-Fan; Ko, Wei-Chun; Lee, Bai-Chin; Lee, Wen-Jeng

    2016-01-01

    Coronary computed tomographic angiography (CCTA) has been widely available since 2004. After that, the diagnostic accuracy of CCTA has been extensively validated with invasive coronary angiography for detection of coronary arterial stenosis. In this paper, we reviewed the updated evidence of the role of CCTA in both scenarios including acute chest pain and screening in asymptomatic adults. Several large-scale studies have been conducted to evaluate the diagnostic value of CCTA in the context of acute chest pain patients. CCTA could play a role in delivering more efficient care. For risk stratification of asymptomatic patients using CCTA, latest studies have revealed incremental benefits. Future studies evaluating the totality of plaque characteristics may be useful for determining the role of noncalcified plaque for risk stratification in asymptomatic individuals. PMID:27122947

  4. Vascular hand-arm vibration syndrome--magnetic resonance angiography.

    PubMed

    Poole, C J M; Cleveland, T J

    2016-01-01

    The diagnosis of vascular hand-arm vibration syndrome (HAVS) requires consistent symptoms, photographic evidence of digital blanching and sufficient exposure to hand-transmitted vibration (HTV; A(8) > 2.5 m/s2). There is no reliable quantitative investigation for distinguishing HAVS from other causes of Raynaud's phenomenon and from normal individuals. Hypothenar and thenar hammer syndromes produce similar symptoms to HAVS but are difficult to diagnose clinically and may be confused with HAVS. Magnetic resonance angiography (MRA) is a safe and minimally invasive method of visualizing blood vessels. Three cases of vascular HAVS are described in which MRA revealed occlusions of the ulnar, radial and superficial palmar arteries. It is proposed that HTV was the cause of these occlusions, rather than blows to the hand unrelated to vibration, the assumed mechanism for the hammer syndromes. All three cases were advised not to expose their hands to HTV despite one of them being at Stockholm vascular stage 2 (early). MRA should be the investigation of choice for stage 2 vascular HAVS or vascular HAVS with unusual features or for a suspected hammer syndrome. The technique is however technically challenging and best done in specialist centres in collaboration with an occupational physician familiar with the examination of HAVS cases. Staging for HAVS should be developed to include anatomical arterial abnormalities as well as symptoms and signs of blanching. Workers with only one artery supplying a hand, or with only one palmar arch, may be at increased risk of progression and therefore should not be exposed to HTV irrespective of their Stockholm stage.

  5. Invasive Candidiasis.

    PubMed

    McCarty, Todd P; Pappas, Peter G

    2016-03-01

    Invasive candidiasis is a collective term that refers to a group of infectious syndromes caused by a variety of species of Candida, 5 of which cause most cases. Candidemia is the most commonly recognized syndrome associated with invasive candidiasis. Certain conditions may influence the likelihood for one species versus another in a specific clinical scenario, and this can have important implications for selection of antifungal therapy and the duration of treatment. Molecular diagnostic technology plays an ever-increasing role as an adjunct to traditional culture-based diagnostics, offering significant potential toward improvement in patient care.

  6. Visual-Functional Mismatch Between Coronary Angiography, Fractional Flow Reserve, and Quantitative Coronary Angiography.

    PubMed

    Safi, Morteza; Eslami, Vahid; Namazi, Mohammad Hasan; Vakili, Hossain; Saadat, Habib; Alipourparsa, Saeid; Adibi, Ali; Movahed, Mohammad Reza

    2016-12-01

    Anatomical and functional mismatches are not uncommon in the assessment of coronary lesions. The aim of this study was to identify clinical and lesion-specific factors affecting angiographic, anatomical, and functional mismatch in intermediate coronary lesions. In patients who underwent coronary angiography for clinical reasons, fractional flow reserve (FFR), and quantitative coronary angiography (QCA) analyses for intermediate stenotic lesions were performed simultaneously. Mismatches between the measured values were analyzed. A total of 95 intermediate lesions were assessed simultaneously by visual angiography, FFR, and QCA. The visual-FFR mismatch was found in 40% of the lesions while reverse visual-FFR mismatch was determined in nearly 14% of the lesions. Mismatch and reverse mismatch between FFR and QCA parameters were observed in 10 and 23% of the lesions. FFR value was significant in 32% of the lesions while visually significant stenosis was shown in 61% of the lesions. Among the visual-FFR reverse mismatch group, the prevalence of culprit lesions within the left anterior descending (LAD) was significantly higher than other vessels (p value < 0.02). There were high frequencies of angiographic, QCA, and functional mismatches in analyses of intermediate coronary lesions. LAD lesions showed the highest mismatch. Angiographic or QCA estimation of lesion severity has consistently resulted in inappropriate stenting of functionally nonsignificant lesions or undertreatment of significant lesions based on FFR.

  7. Fluorescein angiography basic science and engineering.

    PubMed

    Wolfe, D R

    1986-12-01

    Fluorescein angiography is an application of the physical phenomenon of fluorescence, which is phosphorescence in which the quantum mechanical decay curve is so rapid that it appears instantaneous, and it consequently has no afterglow. Sodium fluorescein is excited by light energy between 465 and 490 nm, and it decays into a lower state emitting light energy between 520 and 530 nm as fluorescent radiation. The free electrons available for excitation are reduced by chemical bonding between the fluorescein dye and plasma proteins to which up to 80% of the dye is bound in the bloodstream, thus reducing overall fluorescence. Optimalization of the observed and recorded fluorescence is afforded by providing exciter and barrier filters with as little overlap as possible to reduce or eliminate contrast reducing pseudofluorescence.

  8. [Myocardial perfusion imaging by digital subtraction angiography].

    PubMed

    Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

    1986-03-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Transient cortical blindness following vertebral angiography: a case report.

    PubMed

    Lo, Lai Wan; Chan, Ho Fung; Ma, Ka Fai; Cheng, Lik Fai; Chan, Tony Kt

    2015-02-01

    Transient cortical blindness (TCB) is a rare but well-known complication of cerebral angiography. Its pathophysiology remains uncertain. We would like to report a case of TCB in a patient during a follow up vertebral angiogram for post-coil embolization of left posterior inferior cerebellar artery aneurysm. Patient's vision was resumed spontaneously within 24 hours after angiography, with no residual neurological deficit in subsequent clinical follow up. Multi-modality imaging evaluation including vertebral angiography, brain CT and MRI performed on same day are presented.

  10. [Vascular assessment in stroke codes: role of computed tomography angiography].

    PubMed

    Mendigaña Ramos, M; Cabada Giadas, T

    2015-01-01

    Advances in imaging studies for acute ischemic stroke are largely due to the development of new efficacious treatments carried out in the acute phase. Together with computed tomography (CT) perfusion studies, CT angiography facilitates the selection of patients who are likely to benefit from appropriate early treatment. CT angiography plays an important role in the workup for acute ischemic stroke because it makes it possible to confirm vascular occlusion, assess the collateral circulation, and obtain an arterial map that is very useful for planning endovascular treatment. In this review about CT angiography, we discuss the main technical characteristics, emphasizing the usefulness of the technique in making the right diagnosis and improving treatment strategies.

  11. CT angiography in the abdomen: a pictorial review and update.

    PubMed

    Liu, Peter S; Platt, Joel F

    2014-02-01

    The development of multidetector CT technology and helical scanning techniques has revolutionized the use of CT for primary diagnostic evaluation of the abdominal vasculature, particularly the arterial system. CT angiography has numerous benefits relative to conventional catheter angiography, and has largely replaced catheter-based techniques in many clinical algorithms. This pictorial review and update will cover important technical principles related to modern CT angiography (including contrast delivery and dose considerations), discuss relevant anatomy and variants, and illustrate numerous arterial conditions related to the abdominal aorta and branch vessels.

  12. Accurate, fully-automated registration of coronary arteries for volumetric CT digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Razeto, Marco; Mohr, Brian; Arakita, Kazumasa; Schuijf, Joanne D.; Fuchs, Andreas; Kühl, J. Tobias; Chen, Marcus Y.; Kofoed, Klaus F.

    2014-03-01

    Diagnosis of coronary artery disease with Coronary Computed Tomography Angiography (CCTA) is complicated by the presence of signi cant calci cation or stents. Volumetric CT Digital Subtraction Angiography (CTDSA) has recently been shown to be e ective at overcoming these limitations. Precise registration of structures is essential as any misalignment can produce artifacts potentially inhibiting clinical interpretation of the data. The fully-automated registration method described in this paper addresses the problem by combining a dense deformation eld with rigid-body transformations where calci cations/stents are present. The method contains non-rigid and rigid components. Non-rigid registration recovers the majority of motion artifacts and produces a dense deformation eld valid over the entire scan domain. Discrete domains are identi ed in which rigid registrations very accurately align each calci cation/stent. These rigid-body transformations are combined within the immediate area of the deformation eld using a distance transform to minimize distortion of the surrounding tissue. A recent interim analysis of a clinical feasibility study evaluated reader con dence and diagnostic accuracy in conventional CCTA and CTDSA registered using this method. Conventional invasive coronary angiography was used as the reference. The study included 27 patients scanned with a second-generation 320-row CT detector in which 41 lesions were identi ed. Compared to conventional CCTA, CTDSA improved reader con dence in 13/36 (36%) of segments with severe calci cation and 3/5 (60%) of segments with coronary stents. Also, the false positive rate of CTDSA was reduced compared to conventional CCTA from 18% (24/130) to 14% (19/130).

  13. Pre-procedural combined coronary angiography and stress myocardial perfusion imaging using 320-detector CT in unprotected left main and ostial left anterior descending artery intervention.

    PubMed

    Ko, Brian S; Crossett, Marcus; Seneviratne, Sujith K

    2015-07-01

    Pre-procedural anatomic and functional coronary assessment plays a crucial role in selection of patients suitable for unprotected left main percutaneous coronary intervention. Combined coronary computed tomography angiography and adenosine stress computed tomography myocardial perfusion imaging is a non-invasive technique which may provide this information. This is the first report describing its use to assist patient selection and procedural planning prior to elective left main and ostial left anterior descending artery coronary intervention.

  14. Digital subtraction angiography for preoperative evaluation of extremity tumors

    SciTech Connect

    Paushter, D.M.; Borkowski, G.R.; Buonocore, E.; Belhobek, G.H.; Marks, K.E.

    1983-07-01

    A retrospective study was undertaken to evaluate the role of digital subtraction angiography (DSA) in the surgical planning of musculoskeletal neoplasms. Thirteen patients with primary bone and soft-tissue tumors were examined by CT and DSA. Three patients also had conventional angiography. DSA yielded surgically useful information in 10 patients, comparable to that expected from conventional angiography. DSA was most helpful in demonstrating the presence or absence of major vessel involvement by tumor when this could not be ascertained definitely on CT. Demonstration of mass extent by CT was accurate in 11 patients. Results of this study suggest that the combination of CT and DSA is useful in the preoperative evaluation of selected extremity tumors and should diminish the need for conventional angiography.

  15. Multidetector computed tomography angiography of the celiac trunk and hepatic arterial system: normal anatomy and main variants *

    PubMed Central

    Araujo Neto, Severino Aires; de Mello Júnior, Carlos Fernando; Franca, Henrique Almeida; Duarte, Cláudia Martina Araújo; Borges, Rafael Farias; de Magalhães, Ana Guardiana Ximenes

    2016-01-01

    Although digital angiography remains as the gold standard for imaging the celiac arterial trunk and hepatic arteries, multidetector computed tomography in association with digital images processing by software resources represents a useful tool particularly attractive for its non invasiveness. Knowledge of normal anatomy as well as of its variations is helpful in images interpretation and to address surgical planning on a case-by-case basis. The present essay illustrates several types of anatomical variations of celiac trunk, hepatic artery and its main branches, by means of digitally reconstructed computed tomography images, correlating their prevalence in the population with surgical implications. PMID:26929461

  16. Multidetector computed tomography angiography of the celiac trunk and hepatic arterial system: normal anatomy and main variants.

    PubMed

    Araujo Neto, Severino Aires; de Mello Júnior, Carlos Fernando; Franca, Henrique Almeida; Duarte, Cláudia Martina Araújo; Borges, Rafael Farias; de Magalhães, Ana Guardiana Ximenes

    2016-01-01

    Although digital angiography remains as the gold standard for imaging the celiac arterial trunk and hepatic arteries, multidetector computed tomography in association with digital images processing by software resources represents a useful tool particularly attractive for its non invasiveness. Knowledge of normal anatomy as well as of its variations is helpful in images interpretation and to address surgical planning on a case-by-case basis. The present essay illustrates several types of anatomical variations of celiac trunk, hepatic artery and its main branches, by means of digitally reconstructed computed tomography images, correlating their prevalence in the population with surgical implications.

  17. Registration of ultrasound to CT angiography of kidneys: a porcine phantom study

    NASA Astrophysics Data System (ADS)

    Xiang, Jing; Gill, Sean; Nguan, Christopher; Abolmaesumi, Purang; Rohling, Robert N.

    2010-02-01

    3D ultrasound (US) to computed tomography (CT) registration is a topic of significant interest because it can potentially improve many minimally invasive procedures such as laparoscopic partial nephrectomy. Partial nephrectomy patients often receive preoperative CT angiography, which helps define the important structures of the kidney such as the vasculature. Intraoperatively, dynamic real-time imaging information can be captured using ultrasound and compared with the preoperative data. Providing accurate registration between the two modalities would enhance navigation and guidance for the surgeon. However, one of the major problems of developing and evaluating registration techniques is obtaining sufficiently accurate and realistic phantom data especially for soft tissue. We present a detailed procedure for constructing tissue phantoms using porcine kidneys, which incorporates contrast agent into the tissue such that the kidneys appear representative of in vivo human CT angiography. These phantoms are also imaged with US and resemble US images from human patients. We then perform registration on corresponding CT and US datasets using a simulation-based algorithm. The method simulates an US image from the CT, generating an intermediate modality that resembles ultrasound. This simulated US is then registered to the original US dataset. Embedded fiducial markers provide a gold standard for registration. Being able to test our registration method on realistic datasets facilitates the development of novel CT to US registration techniques such that we can generate an effective method for human studies.

  18. Multidetector computed tomography angiography of the renal arteries: normal anatomy and its variations*

    PubMed Central

    de Mello Júnior, Carlos Fernando; Araujo Neto, Severino Aires; de Carvalho Junior, Arlindo Monteiro; Rebouças, Rafael Batista; Negromonte, Gustavo Ramalho Pessoa; de Oliveira, Carollyne Dantas

    2016-01-01

    Conventional angiography is still considered the gold standard for the study of the anatomy and of vascular diseases of the abdomen. However, the advent of multidetector computed tomography and techniques of digital image reconstruction has provided an alternative means of performing angiography, without the risks inherent to invasive angiographic examinations. Therefore, within the field of radiology, there is an ever-increasing demand for deeper knowledge of the anatomy of the regional vasculature and its variations. Variations in the renal vascular system are relatively prevalent in the venous and arterial vessels. For various conditions in which surgical planning is crucial to the success of the procedure, knowledge of this topic is important. The aim of this study was to familiarize the general radiologist with variations in the renal vascular system. To that end, we prepared a pictorial essay comprising multidetector computed tomography images obtained in a series of cases. We show patterns representative of the most common anatomical variations in the arterial blood supply to the kidneys, calling attention to the nomenclature, as well as to the clinical and surgical implications of such variations. PMID:27403020

  19. Subtraction CT angiography for the detection of intracranial aneurysms: A meta-analysis

    PubMed Central

    FENG, TIAN-YING; HAN, XUE-FENG; LANG, RUI; WANG, FEI; WU, QIONG

    2016-01-01

    The aim of this meta-analysis was to investigate the accuracy of subtraction computed tomography angiography (CTA) for diagnosing intracranial aneurysms. A systematic literature search up to January 1, 2013 was performed in PubMed. Two independent reviewers selected 8 studies that compared subtraction CTA with digital subtraction angiography. Data from the studies were used to construct a 2×2 contingency table on a per-patient basis in ≥5 diseased and 5 non-diseased patients, with additional data on a per-aneurysm basis. Overall, subtraction CTA had a pooled sensitivity of 99% [95% confidence interval (CI), 95–100%] and specificity of 94% (95% CI, 86–97%) for detecting and ruling out cerebral aneurysms, respectively, on a per-patient basis. On a per-aneurysm basis, the pooled sensitivity was 96% (95% CI, 90–99%), and the specificity was 91% (95% CI, 85–95%). In conclusion, subtraction CTA is a highly sensitive, specific and non-invasive method for the diagnosis and evaluation of intracranial aneurysms. PMID:27168830

  20. Multidetector computed tomography angiography of the renal arteries: normal anatomy and its variations.

    PubMed

    de Mello Júnior, Carlos Fernando; Araujo Neto, Severino Aires; de Carvalho Junior, Arlindo Monteiro; Rebouças, Rafael Batista; Negromonte, Gustavo Ramalho Pessoa; de Oliveira, Carollyne Dantas

    2016-01-01

    Conventional angiography is still considered the gold standard for the study of the anatomy and of vascular diseases of the abdomen. However, the advent of multidetector computed tomography and techniques of digital image reconstruction has provided an alternative means of performing angiography, without the risks inherent to invasive angiographic examinations. Therefore, within the field of radiology, there is an ever-increasing demand for deeper knowledge of the anatomy of the regional vasculature and its variations. Variations in the renal vascular system are relatively prevalent in the venous and arterial vessels. For various conditions in which surgical planning is crucial to the success of the procedure, knowledge of this topic is important. The aim of this study was to familiarize the general radiologist with variations in the renal vascular system. To that end, we prepared a pictorial essay comprising multidetector computed tomography images obtained in a series of cases. We show patterns representative of the most common anatomical variations in the arterial blood supply to the kidneys, calling attention to the nomenclature, as well as to the clinical and surgical implications of such variations.

  1. Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFRCT: outcome and resource impacts study

    PubMed Central

    Douglas, Pamela S.; Pontone, Gianluca; Hlatky, Mark A.; Patel, Manesh R.; Norgaard, Bjarne L.; Byrne, Robert A.; Curzen, Nick; Purcell, Ian; Gutberlet, Matthias; Rioufol, Gilles; Hink, Ulrich; Schuchlenz, Herwig Walter; Feuchtner, Gudrun; Gilard, Martine; Andreini, Daniele; Jensen, Jesper M.; Hadamitzky, Martin; Chiswell, Karen; Cyr, Derek; Wilk, Alan; Wang, Furong; Rogers, Campbell; De Bruyne, Bernard

    2015-01-01

    Aims In symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown. Methods and results At 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFRCT (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFRCT-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFRCT arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53–69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFRCT results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFRCT) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFRCT arms. Conclusions Computed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD. PMID:26330417

  2. Digital subtraction angiography in pediatric cerebrovascular occlusive disease

    SciTech Connect

    Faerber, E.N.; Griska, L.A.B.; Swartz, J.D.; Capitanio, M.A.; Popky, G.L.

    1984-08-01

    While conventional angiography has been used to demonstrate cerebrovascular occlusive disease in the past, digital subtraction angiography (DSA) is capable of showing progressive vascular involvement with ease, simplicity, and extremely low morbidity, making it particularly well suited for children and outpatients either alone or coordinated with computed tomography. The authors discuss the usefulness and advantages of DSA as demonstrated in 7 infants and children with hemiplegia, 4 of whom had sickle-cell disease.

  3. Imaging Foveal Microvasculature: Optical Coherence Tomography Angiography Versus Adaptive Optics Scanning Light Ophthalmoscope Fluorescein Angiography

    PubMed Central

    Mo, Shelley; Krawitz, Brian; Efstathiadis, Eleni; Geyman, Lawrence; Weitz, Rishard; Chui, Toco Y. P.; Carroll, Joseph; Dubra, Alfredo; Rosen, Richard B.

    2016-01-01

    Purpose To compare the use of optical coherence tomography angiography (OCTA) and adaptive optics scanning light ophthalmoscope fluorescein angiography (AOSLO FA) for characterizing the foveal microvasculature in healthy and vasculopathic eyes. Methods Four healthy controls and 11 vasculopathic patients (4 diabetic retinopathy, 4 retinal vein occlusion, and 3 sickle cell retinopathy) were imaged with OCTA and AOSLO FA. Foveal perfusion maps were semiautomatically skeletonized for quantitative analysis, which included foveal avascular zone (FAZ) metrics (area, perimeter, acircularity index) and vessel density in three concentric annular regions of interest. On each set of OCTA and AOSLO FA images, matching vessel segments were used for lumen diameter measurement. Qualitative image comparisons were performed by visual identification of microaneurysms, vessel loops, leakage, and vessel segments. Results Adaptive optics scanning light ophthalmoscope FA and OCTA showed no statistically significant differences in FAZ perimeter, acircularity index, and vessel densities. Foveal avascular zone area, however, showed a small but statistically significant difference of 1.8% (P = 0.004). Lumen diameter was significantly larger on OCTA (mean difference 5.7 μm, P < 0.001). Microaneurysms, fine structure of vessel loops, leakage, and some vessel segments were visible on AOSLO FA but not OCTA, while blood vessels obscured by leakage were visible only on OCTA. Conclusions Optical coherence tomography angiography is comparable to AOSLO FA at imaging the foveal microvasculature except for differences in FAZ area, lumen diameter, and some qualitative features. These results, together with its ease of use, short acquisition time, and avoidance of potentially phototoxic blue light, support OCTA as a tool for monitoring ocular pathology and detecting early disease. PMID:27409463

  4. Three-dimensional contrast-enhanced magnetic resonance angiography of the thoracic vasculature.

    PubMed

    Leung, D A; Debatin, J F

    1997-01-01

    Magnetic resonance angiography (MRA) has become a useful non-invasive imaging technique for the assessment of vascular disease. Due to limitations such as respiratory motion artefacts, saturations problems, and long acquisition times, applications of MRA in the thorax have largely been restricted to imaging of the aorta. The recent introduction of breath-hold three-dimensional (3D) contrast-enhanced MRA promises not only to enhance conventional MR protocols for aortic imaging, but to extend the clinical indications of MRI to diseases affecting other vascular structures of the thorax, most notably the pulmonary arteries. This article describes the technical aspects of contrast-enhanced 3D MRA and reviews existing and potential future clinical applications.

  5. Comparison of echocardiography and angiography in determining the cause of severe aortic regurgitation.

    PubMed

    DePace, N L; Nestico, P F; Kotler, M N; Mintz, G S; Kimbiris, D; Goel, I P; Glazier-Laskey, E E; Ross, J

    1984-01-01

    To assess the accuracy of echocardiography in determining the cause of aortic regurgitation M mode and cross sectional echocardiography were compared with angiography in 43 patients with predominant aortic regurgitation. Each patient had all three investigations performed during the same admission to hospital. In each instance, the cause of aortic regurgitation was confirmed at surgery or necropsy. Seventeen patients had rheumatic aortic valve disease, 13 bacterial endocarditis with a perforated or partially destroyed cusp, five a bicuspid aortic valve (four with a history of endocarditis), and eight aortic regurgitation secondary to aortic root dilatation or aneurysm. Overall sensitivity of echocardiography and aortography was 84% in determining the cause of aortic regurgitation. Thus, rheumatic valve disease and endocarditis appear to be the most common causes of severe aortic regurgitation in this hospital based population. Furthermore, echocardiography is a sensitive non-invasive technique for determining the cause of aortic regurgitation and allows differentiation of valvular from root causes of aortic regurgitation.

  6. Comparison of echocardiography and angiography in determining the cause of severe aortic regurgitation.

    PubMed Central

    DePace, N L; Nestico, P F; Kotler, M N; Mintz, G S; Kimbiris, D; Goel, I P; Glazier-Laskey, E E; Ross, J

    1984-01-01

    To assess the accuracy of echocardiography in determining the cause of aortic regurgitation M mode and cross sectional echocardiography were compared with angiography in 43 patients with predominant aortic regurgitation. Each patient had all three investigations performed during the same admission to hospital. In each instance, the cause of aortic regurgitation was confirmed at surgery or necropsy. Seventeen patients had rheumatic aortic valve disease, 13 bacterial endocarditis with a perforated or partially destroyed cusp, five a bicuspid aortic valve (four with a history of endocarditis), and eight aortic regurgitation secondary to aortic root dilatation or aneurysm. Overall sensitivity of echocardiography and aortography was 84% in determining the cause of aortic regurgitation. Thus, rheumatic valve disease and endocarditis appear to be the most common causes of severe aortic regurgitation in this hospital based population. Furthermore, echocardiography is a sensitive non-invasive technique for determining the cause of aortic regurgitation and allows differentiation of valvular from root causes of aortic regurgitation. Images PMID:6689919

  7. Invasive coronary imaging: any role in primary and secondary prevention?

    PubMed

    Di Mario, Carlo; Moreno, Pedro R

    2016-06-21

    This review discusses the possibilities offered by new modalities of non-invasive and invasive coronary imaging in an effort to optimize risk stratification for coronary artery disease, and identify subgroups at high risk that may benefit from an aggressive, personalized approach, with access to a growing number of novel drugs and interventions. Special emphasis is placed on the progress of novel invasive imaging techniques such as near infrared spectroscopy and optical coherence tomography that can reliably identify thin-capped fibroatheromas. Multiple trials are exploring the feasibility of these techniques to guide modulation of risk factor control and treatment of non-flow limiting lesions at high risk of destabilization and progression in patients undergoing clinically mandated angioplasty of angiographically critical lesions. Asymptomatic patients at high risk of cardiovascular ischaemic events may also benefit, with the intermediate step of a wider application of calcium score and angiography with multi-slice computed tomography, by a selective use of invasive imaging.

  8. Correlation between magnetic resonance angiography (MRA) and quantitative coronary angiography (QCA) in ectatic coronary vessels.

    PubMed

    Mavrogeni, Sophie I; Manginas, Athanassios; Papadakis, Emmanouil; Foussas, Stefanos; Douskou, Marouso; Baras, Panagiotis; Seimenis, Ioannis; Cokkinos, Dennis V

    2004-01-01

    Coronary artery ectasia (CAE) is defined as a dilatation of an arterial segment to a diameter at least 1.5 times that of the adjacent normal artery. The correct follow-up of ectatic vessels is hampered by the need for repeat angiograms. In this work we compared quantitative coronary angiography (QCA) measurements of the diameter of the proximal most ectatic part of coronary vessels, with corresponding measurements obtained by magnetic resonance angiography (MRA) using both gradient echo and turbo spin echo imaging sequences. Fifteen patients (14 male), aged 45-65 years, with known CAE were prospectively studied. Two electrocardiogram (ECG)-triggered pulse sequences were implemented for coronary magnetic resonance angiography. The first was a three-dimensional (3D), segmented, k-space gradient-echo sequence, employing a T2-weighted preparation prepulse and a frequency-selective, fat-saturation prepulse to enhance "white blood" (WB) contrast of the coronary arteries. The second sequence was an M2D dual Inversion Recovery (IR) Turbo Spin-Echo with a linear k-space acquisition scheme, providing "black-blood" (BB) contrast of the coronaries. All scans were carried out with the patient free breathing using a 2D, real-time Navigator beam, for respiratory motion tracking and gating. All patients underwent QCA, and the diameter of the proximal most ectatic part of each vessel was measured and compared with "white-blood" and "black-blood" MRA measurements. The average length of continuously visualized LM, LAD, LCx, and RCA by MRA was 2.5 +/- 0.3, 5.8 +/- 0.8, 3.9 +/- 1.0, and 7.2 +/- 1.2 cm, respectively. There were no statistically significant differences between diameter measurements of the proximal most ectatic part of each vessel, obtained with WB and BB sequences. There was a close correlation between MRA and QCA measurements (r = 0.87, p < 0.001). Bland-Altman analysis showed no systematic differences between the examined methods, over the whole range of vessel

  9. Unusual Congenital Aortic Anomaly with Rare Common Celiamesenteric Trunk Variation: MR Angiography and Digital Substraction Angiography Findings

    SciTech Connect

    Tosun, Ozgur Sanlidilek, Umman; Cetin, Huseyin; Ozdemir, Ozcan; Kurt, Aydin; Sakarya, Mehmet Emin; Tas, Ismet

    2007-09-15

    Magnetic resonance angiography and digital substraction angiography (DSA) findings in a case with a rare congenital thoracoabdominal aortic hypoplasia and common celiamesenteric trunk variation with occlusion of infrarenal abdominal aorta are described here. To our knowledge, this aortic anomaly has not been previously described in the English literature. DSA is the optimum imaging modality for determination of aortic hypoplasia, associated vascular malformations, collateral vessels, and direction of flow within vessels.

  10. Photodynamic therapy monitoring with optical coherence angiography

    NASA Astrophysics Data System (ADS)

    Sirotkina, M. A.; Matveev, L. A.; Shirmanova, M. V.; Zaitsev, V. Y.; Buyanova, N. L.; Elagin, V. V.; Gelikonov, G. V.; Kuznetsov, S. S.; Kiseleva, E. B.; Moiseev, A. A.; Gamayunov, S. V.; Zagaynova, E. V.; Feldchtein, F. I.; Vitkin, A.; Gladkova, N. D.

    2017-02-01

    Photodynamic therapy (PDT) is a promising modern approach for cancer therapy with low normal tissue toxicity. This study was focused on a vascular-targeting Chlorine E6 mediated PDT. A new angiographic imaging approach known as M-mode-like optical coherence angiography (MML-OCA) was able to sensitively detect PDT-induced microvascular alterations in the mouse ear tumour model CT26. Histological analysis showed that the main mechanisms of vascular PDT was thrombosis of blood vessels and hemorrhage, which agrees with angiographic imaging by MML-OCA. Relationship between MML-OCA-detected early microvascular damage post PDT (within 24 hours) and tumour regression/regrowth was confirmed by histology. The advantages of MML-OCA such as direct image acquisition, fast processing, robust and affordable system opto-electronics, and label-free high contrast 3D visualization of the microvasculature suggest attractive possibilities of this method in practical clinical monitoring of cancer therapies with microvascular involvement.

  11. Image quality metrics for optical coherence angiography

    PubMed Central

    Lozzi, Andrea; Agrawal, Anant; Boretsky, Adam; Welle, Cristin G.; Hammer, Daniel X.

    2015-01-01

    We characterized image quality in optical coherence angiography (OCA) en face planes of mouse cortical capillary network in terms of signal-to-noise ratio (SNR) and Weber contrast (Wc) through a novel mask-based segmentation method. The method was used to compare two adjacent B-scan processing algorithms, (1) average absolute difference (AAD) and (2) standard deviation (SD), while varying the number of lateral cross-sections acquired (also known as the gate length, N). AAD and SD are identical at N = 2 and exhibited similar image quality for N<10. However, AAD is relatively less susceptible to bulk tissue motion artifact than SD. SNR and Wc were 15% and 35% higher for AAD from N = 25 to 100. In addition data sets were acquired with two objective lenses with different magnifications to quantify the effect of lateral resolution on fine capillary detection. The lower power objective yielded a significant mean broadening of 17% in Full Width Half Maximum (FWHM) diameter. These results may guide study and device designs for OCA capillary and blood flow quantification. PMID:26203372

  12. Photodynamic therapy monitoring with optical coherence angiography

    PubMed Central

    Sirotkina, M. A.; Matveev, L. A.; Shirmanova, M. V.; Zaitsev, V. Y.; Buyanova, N. L.; Elagin, V. V.; Gelikonov, G. V.; Kuznetsov, S. S.; Kiseleva, E. B.; Moiseev, A. A.; Gamayunov, S. V.; Zagaynova, E. V.; Feldchtein, F. I.; Vitkin, A.; Gladkova, N. D.

    2017-01-01

    Photodynamic therapy (PDT) is a promising modern approach for cancer therapy with low normal tissue toxicity. This study was focused on a vascular-targeting Chlorine E6 mediated PDT. A new angiographic imaging approach known as M-mode-like optical coherence angiography (MML-OCA) was able to sensitively detect PDT-induced microvascular alterations in the mouse ear tumour model CT26. Histological analysis showed that the main mechanisms of vascular PDT was thrombosis of blood vessels and hemorrhage, which agrees with angiographic imaging by MML-OCA. Relationship between MML-OCA-detected early microvascular damage post PDT (within 24 hours) and tumour regression/regrowth was confirmed by histology. The advantages of MML-OCA such as direct image acquisition, fast processing, robust and affordable system opto-electronics, and label-free high contrast 3D visualization of the microvasculature suggest attractive possibilities of this method in practical clinical monitoring of cancer therapies with microvascular involvement. PMID:28148963

  13. Acceptance of Combined Coronary CT Angiography and Myocardial CT Perfusion versus Conventional Coronary Angiography in Patients with Coronary Stents—Intraindividual Comparison

    PubMed Central

    Martus, Peter; Laule, Michael; Dewey, Marc; Schönenberger, Eva

    2015-01-01

    Objectives To evaluate how well patients with coronary stents accept combined coronary computed tomography angiography (CTA) and myocardial CT perfusion (CTP) compared with conventional coronary angiography (CCA). Background While combined CTA and CTP may improve diagnostic accuracy compared with CTA alone, patient acceptance of CTA/CTP remains to be defined. Methods A total of 90 patients with coronary stents prospectively underwent CTA/CTP (both with contrast agent, CTP with adenosine) and CCA as part of the CARS-320 study. In this group, an intraindividual comparison of patient acceptance of CTA, CTP, and CCA was performed. Results CTP was experienced to be significantly more painful than CTA (p<0.001) and was associated with a higher frequency of dyspnea (p<0.001). Comparison of CTA/CTP with CCA revealed no significant differences in terms of pain (p = 0.141) and comfort (p = 0.377). Concern before CTA/CTP and CCA and overall satisfaction were likewise not significantly different (p = 0.097 and p = 0.123, respectively). Nevertheless, about two thirds (n = 60, 68%) preferred CTA/CTP to CCA (p<0.001). Moreover, patients felt less helpless during CTA/CTP than during CCA (p = 0.026). Lack of invasiveness and absence of pain were the most frequently mentioned advantages of CTA/CTP over CCA in our patient population. Conclusions CCA and combined CTA/CTP are equally well accepted by patients; however, more patients prefer CTA/CTP. CTP was associated with more intense pain than CTA and more frequently caused dyspnea than CTA alone. Trial Registration ClinicalTrials.gov NCT00967876 PMID:26327127

  14. Diabetic Macular Ischemia Diagnosis: Comparison between Optical Coherence Tomography Angiography and Fluorescein Angiography

    PubMed Central

    Lima, Talita Toledo; Louzada, Ricardo Noguera; Rassi, Alessandra Thome; Isaac, David Leonardo Cruvinel; Avila, Marcos

    2016-01-01

    Purpose. To compare fluorescein angiography (FA) and optical coherence tomography angiography (OCTA) images of foveal avascular zone (FAZ) in patients with diabetic retinopathy (DR) with and without diabetic macular ischemia (DMI). Methods. The Wilcoxon signed-rank test was used to compare area measurements and p values of <0.05 were considered statistically significant. FA and OCTA images were independently graded by 2 observers that reached agreement regarding quantitative DMI according established protocols. The ischemic area was divided into “large” macular ischemia (superior to 0.32 mm2) and “small” (inferior to 0.32 mm2) groups. Quantitative analyses of the FAZ were performed using custom software. Results. Thirty-four eyes from 34 diabetic patients were enrolled. Subjects with DMI presented a mean area on FA and OCTA of 0.68 ± 0.53 mm2 and 0.58 ± 0.35 mm2, respectively (p = 0.1374). Patients without DMI presented a mean area on FA and OCTA of 0.19 ± 0.67 mm2 and 0.20 ± 0.79 mm2, respectively (p = 0.9594). The ICC for the FAZ measurements between the 2 observers on FA and OCTA was 0.96 and 0.92, respectively. Conclusion. OCTA represents a novel technique for the diagnosis of DMI and it may become an alternative to FA for this purpose. PMID:27891250

  15. Early surgery after angiography in patients scheduled for valve replacement.

    PubMed

    Dayan, Victor; Stanham, Roberto; Soca, Gerardo; Genta, Fernando; Mariño, Jorge; Lorenzo, Alvaro

    2017-01-01

    Background There are limited data regarding the risks of cardiac surgery early after coronary angiography in patients scheduled for isolated aortic and/or mitral valve replacement. Our aim was to evaluate the risk of early surgery after coronary angiography in these patients. Methods We retrospectively analyzed data of 1044 patients who underwent isolated aortic and/or mitral valve replacement from 2006 to 2014. Baseline, operative, and postoperative variables were collected. The patients were divided into 3 groups based on the interval between coronary angiography and surgery: ≤3 days ( n = 216), 4-7 days ( n = 109), and ≥8 days ( n = 719). We evaluated hospital mortality and postoperative acute kidney injury. Subgroup analysis was performed according to preoperative creatinine clearance. Results Postoperative creatinine clearance was lower in patients who underwent surgery ≤3 days after coronary angiography (63.57 ± 38.52 mL min(-1)) compared to ≥8 days after coronary angiography (74.56 ± 54.25 mL min(-1), p = 0.015). Patients who underwent surgery ≤3 days after coronary angiography had higher hospital mortality when preoperative creatinine clearance was ≤60 mL min(-1) (12% vs. 4% for creatinine clearance ≤and >60 mL min(-1), respectively; p = 0.039). Predictors of hospital mortality were New York Heart Association class and postoperative creatinine clearance. Conclusion Hospital mortality was higher in patients with decreased preoperative renal function who underwent surgery within the first 3 days after coronary angiography. Delaying surgery in this subgroup of patients could be a good strategy.

  16. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography: design and implementation of the CORE320 multicenter, multinational diagnostic study.

    PubMed

    Vavere, Andrea L; Simon, Gregory G; George, Richard T; Rochitte, Carlos E; Arai, Andrew E; Miller, Julie M; Di Carli, Marcello; Arbab-Zadeh, Armin; Zadeh, Armin A; Dewey, Marc; Niinuma, Hiroyuki; Laham, Roger; Rybicki, Frank J; Schuijf, Joanne D; Paul, Narinder; Hoe, John; Kuribyashi, Sachio; Sakuma, Hajime; Nomura, Cesar; Yaw, Tan Swee; Kofoed, Klaus F; Yoshioka, Kunihiro; Clouse, Melvin E; Brinker, Jeffrey; Cox, Christopher; Lima, Joao A C

    2011-01-01

    Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8 countries worldwide. CT has the potential to assess both anatomy and physiology in a single imaging session. The co-primary aim of the CORE320 study is to define the per-patient diagnostic accuracy of the combination of coronary CTA and myocardial CTP to detect physiologically significant coronary artery disease compared with (1) the combination of conventional coronary angiography and SPECT-MPI and (2) conventional coronary angiography alone. If successful, the technology could revolutionize the management of patients with symptomatic CAD.

  17. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia

    PubMed Central

    Zhang, Yang; Chen, Ming; Bao, Shengde

    2016-01-01

    Introduction. Transient global amnesia (TGA) following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360) or cardiac angiography (4 in 8817) and no case with TGA following peripheral angiography (0 in 7659). Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p = 0.022). Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p = 0.82) and different contrast agents (p = 0.619). Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography. PMID:27419129

  18. Coronary artery angiography and myocardial viability imaging: a 3.0-T contrast-enhanced magnetic resonance coronary artery angiography with Gd-BOPTA.

    PubMed

    Yun, Hong; Jin, Hang; Yang, Shan; Huang, Dong; Chen, Zhang-wei; Zeng, Meng-su

    2014-01-01

    With improving MR sequence, phase-array coil and image quality, cardiac magnetic resonance imaging is becoming a promising method for a comprehensive non-invasive evaluation of coronary artery and myocardial viability. The study aimed to evaluate contrast-enhanced whole-heart coronary MR angiography (CE WH-CMRA) at 3.0-Tesla for the diagnosis of significant stenosis (≥50%) and detection of myocardial infarction (MI) in patients with suspected coronary artery disease (CAD). CE WH-CMRA was performed in consecutive 70 patients with suspected CAD by using a 3.0-T MR system. A respiratory-gated, electrocardiography-triggered, inversion-recovery, segmented fast low angle shot sequence (TI = 200 ms) was used. Data acquisition began 60 s after the slow injection of Gd-BOPTA (0.2 mmol/kg body weight, at an injection rate 0.3 ml/s). At last, breath-hold 2D-PSIR-SSFP sequence was performed. Diagnostic accuracy of CE WH-CMRA in detecting significant stenosis (≥50%) was evaluated using invasive coronary angiography as the referenced standard. The MI region appearing as high signal intensity visualized on CEWH-CMRA and 2D-PSIR-SSFP images were compared and analyzed. CE WH-CMRA correctly identified 42 of 44 patients with significant CAD. The overall sensitivity, specificity, negative predictive value, positive predictive value and accuracy for diagnosing significant CAD was 83.6, 95.8, 96.0, 82.8 and 93.4% respectively. The MI region detected by WH-CMRA and 2D-PSIR-SSFP were consistent in 10 patients and these segments manifested with transmural or subendocardial enhancement patterns. Only one MI patient was judged inconsistent between WH-CMRA and 2D-PSIR-SSFP, who was confirmed by clinical and electrocardiogram results. The enhancement pattern in this patient was spotted and focal in 2D-PSIR-SSFP, but was dismissed by WH-CMRA. It is feasible to obtain information about coronary artery stenosis and myocardial viability in a single CE WH-CMRA with administration of Gd-BOPTA.

  19. Upper Extremity Runoff: Pearls and Pitfalls in Computed Tomography Angiography and Magnetic Resonance Angiography.

    PubMed

    Nagpal, Prashant; Maller, Vinod; Garg, Gunjan; Hedgire, Sandeep; Khandelwal, Ashish; Kalva, Sanjeeva; Steigner, Michael L; Saboo, Sachin S

    Upper extremity vasculature can be affected by various traumatic and nontraumatic pathologies; however, the evaluation of these arteries can be challenging for the radiologists as well as for the clinicians. After an accurate history and clinical examination, imaging plays a vital role in the diagnosis and treatment planning of these patients. Depending on the urgency and the indication, upper extremity arteries may be evaluated by ultrasonography with color Doppler, computed tomography (CT), magnetic resonance imaging (MRI), or digital subtraction angiography. This review article discusses relevant imaging anatomy of the upper extremity arteries, presents CT and MRI protocols, briefly describes the state-of-the-art CT and MRI of various pathologies affecting the upper extremity arteries, and summarizes the important pearls needed for busy practicing radiologist.

  20. Split-spectrum phase-gradient optical coherence tomography angiography

    PubMed Central

    Liu, Gangjun; Jia, Yali; Pechauer, Alex D.; Chandwani, Rahul; Huang, David

    2016-01-01

    A phase gradient angiography (PGA) method is proposed for optical coherence tomography (OCT). This method allows the use of phase information to map the microvasculature in tissue without the correction of bulk motion and laser trigger jitter induced phase artifacts. PGA can also be combined with the amplitude/intensity to improve the performance. Split-spectrum technique can further increase the signal to noise ratio by more than two times. In-vivo imaging of human retinal circulation is shown with a 70 kHz, 840 nm spectral domain OCT system and a 200 kHz, 1050 nm swept source OCT system. Four different OCT angiography methods are compared. The best performance was achieved with split-spectrum amplitude and phase-gradient angiography. PMID:27570689

  1. Optical Coherence Tomography Angiography in Mice: Comparison with Confocal Scanning Laser Microscopy and Fluorescein Angiography

    PubMed Central

    Giannakaki-Zimmermann, Helena; Kokona, Despina; Wolf, Sebastian; Ebneter, Andreas; Zinkernagel, Martin S.

    2016-01-01

    Purpose Optical coherence tomography angiography (OCT-A) allows noninvasive visualization of retinal vessels in vivo. OCT-A was used to characterize the vascular network of the mouse retina and was compared with fluorescein angiography (FA) and histology. Methods In the present study, OCT-A based on a Heidelberg Engineering Spectralis system was used to investigate the vascular network in mice. Data was compared with FA and confocal microscopy of flat-mount histology stained with isolectin IB4. For quantitative analysis the National Cancer Institute's AngioTool software was used. Vessel density, the number of vessel junctions, and endpoints were measured and compared between the imaging modalities. Results The configuration of the superficial capillary network was comparable with OCT-A and flat-mount histology in BALBc mice. However, vessel density and the number of vessel junctions per region of interest (P = 0.0161 and P = 0.0015, respectively) in the deep vascular network of BALBc mice measured by OCT-A was significantly higher than with flat-mount histology. In C3A.Cg-Pde6b+Prph2Rd2/J mice, where the deep capillary plexus is absent, analysis of the superficial network provided similar results for all three imaging modalities. Conclusion OCT-A is a helpful imaging tool for noninvasive, in vivo imaging of the vascular plexus in mice. It may offer advantages over FA and confocal microscopy especially for imaging the deep vascular plexus. Translational Relevance The present study shows that OCT-A can be employed for small animal imaging to assess the vascular network and offers advantages over flat-mount histology and FA. PMID:27570710

  2. MR pulmonary angiography and perfusion imaging: recent advances.

    PubMed

    Hatabu, H

    1997-10-01

    Recent advances in MR pulmonary angiography and MR perfusion imaging are reviewed, focusing on two principal areas of technical development: (1) the availability of MR scanners equipped with enhanced gradient systems; and (2) new trends in MR angiography using gadolinium contrast agents or labeling of blood with an inversion recovery radiofrequency pulse in place of the more traditional methods using naturally flowing spins as the source of intravascular signal. These recent developments in MR have significant potential for clinical imaging of the pulmonary vasculature, particularly for the diagnosis of pulmonary embolism, and are now opening windows to functional MR imaging of the lung.

  3. Anomalous left main coronary artery detected by CT angiography.

    PubMed

    Forte, Ernesto; Inglese, Marianna; Infante, Teresa; Schiano, Concetta; Napoli, Claudio; Soricelli, Andrea; Salvatore, Marco; Tedeschi, Carlo

    2016-10-01

    The growing improvements of computed tomography have made this technique more and more available for cardiac evaluation. Coronary artery anomalies (CAAs) are often incidental findings in subjects with suspected coronary artery disease (CAD) undergoing coronary angiography or computed tomography coronary angiography (CTCA). In some cases, CAAs can be clinically relevant so their identification could change radically patient management and treatment. We report the case of a 68-year-old male patient with known CAD and associated anomalous origination of the left coronary artery from the opposite sinus.

  4. Technical innovation: Multidimensional computerized software enabled subtraction computed tomographic angiography.

    PubMed

    Bhatia, Mona; Rosset, Antoine; Platon, Alexandra; Didier, Dominique; Becker, Christoph D; Poletti, Pierre-Alexandre

    2010-01-01

    Computed tomographic angiography (CTA) is a frequent noninvasive alternative to digital subtraction angiography. We previously reported the development of a new subtraction software to overcome limitations of adjacent bone and calcification in CT angiographic subtraction. Our aim was to further develop and improve this fast and automated computerized software, universally available for free use and compatible with most CT scanners, thus enabling better delineation of vascular structures, artifact reduction, and shorter reading times with potential clinical benefits. This computer-based free software will be available as an open source in the next release of OsiriX at the Web site http://www.osirix-viewer.com.

  5. Ultra-Wide-Field Fluorescein Angiography in Microscopic Polyangiitis

    PubMed Central

    Philander, Shannon A.; Ter-Zakarian, Anna; Rao, Narsing A.; Rodger, Damien C.

    2016-01-01

    A 25-year-old Hispanic female presented with 5 months of dry eyes and 2 months of bilateral photophobia and decreased vision. On examination, she had bilateral anterior uveitis and mild disc edema of the left eye. A complete infectious and inflammatory work-up was positive for elevated antinuclear antibodies and p-ANCA, leading to a diagnosis of microscopic polyangiitis. One year after initial treatment and steroid taper, an ultra-wide-field fluorescein angiography revealed peripheral vasculitis, outside of the standard traditional field of view, leading to an increase in immunomodulatory therapy and illustrating the utility of wide-field angiography for managing patients with uveitis. PMID:27872779

  6. Three-dimensional MDCT angiography of splanchnic arteries: pearls and pitfalls.

    PubMed

    Dohan, A; Dautry, R; Guerrache, Y; Fargeaudou, Y; Boudiaf, M; Le Dref, O; Sirol, M; Soyer, P

    2015-02-01

    Fast scanning along with high resolution of multidetector computed tomography (MDCT) have expanded the role of non-invasive imaging of splanchnic arteries. Advancements in both MDCT scanner technology and three-dimensional (3D) imaging software provide a unique opportunity for non-invasive investigation of splanchnic arteries. Although standard axial computed tomography (CT) images allow identification of splanchnic arteries, visualization of small or distal branches is often limited. Similarly, a comprehensive assessment of the complex anatomy of splanchnic arteries is often beyond the reach of axial images. However, the submillimeter collimation that can be achieved with MDCT scanners now allows the acquisition of true isotropic data so that a high spatial resolution is now maintained in any imaging plane and in 3D mode. This ability to visualize the complex network of splanchnic arteries using 3D rendering and multiplanar reconstruction is of major importance for an optimal analysis in many situations. The purpose of this review is to discuss and illustrate the role of 3D MDCT angiography in the detection and assessment of abnormalities of splanchnic arteries as well as the limitations of the different reconstruction techniques.

  7. Optical Coherence Tomography Angiography to Estimate Retinal Blood Flow in Eyes with Retinitis Pigmentosa.

    PubMed

    Sugahara, Masako; Miyata, Manabu; Ishihara, Kenji; Gotoh, Norimoto; Morooka, Satoshi; Ogino, Ken; Hasegawa, Tomoko; Hirashima, Takako; Yoshikawa, Munemitsu; Hata, Masayuki; Muraoka, Yuki; Ooto, Sotaro; Yamashiro, Kenji; Yoshimura, Nagahisa

    2017-04-13

    Ophthalmologists sometimes face difficulties in identifying the origin of visual acuity (VA) loss in a retinitis pigmentosa (RP) patient, particularly before cataract surgery: cataract or the retinal disease state. Therefore, it is important to identify the significant factors correlating with VA. Nowadays, retinal blood flow in superficial and deep layers can be estimated non-invasively using optical coherence tomography angiography (OCTA). We estimated blood flow per retinal layer by using OCTA; investigated the correlation between VA and other parameters including blood flow and retinal thickness; and identified the most associated factor with VA in patients with RP. OCTA images in 68 of consecutive 110 Japanese RP patients were analysable (analysable RP group). Thirty-two age- and axial length-matched healthy eyes (control group) were studied. In the analysable RP group, the parafoveal flow density in superficial and deep layers was 47.0 ± 4.9% and 52.4 ± 5.5%, respectively, which was significantly lower than that in controls. Using multivariate analysis, we found that the parafoveal flow density in the deep layer and superficial foveal avascular area were the factors associated with VA. Non-invasive estimation of retinal blood flow per retinal layer using OCTA is useful for predicting VA in RP patients.

  8. Esophagectomy - minimally invasive

    MedlinePlus

    Minimally invasive esophagectomy; Robotic esophagectomy; Removal of the esophagus - minimally invasive; Achalasia - esophagectomy; Barrett esophagus - esophagectomy; Esophageal cancer - esophagectomy - laparoscopic; Cancer of the ...

  9. Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database

    SciTech Connect

    Petereit, D.; Mehta, M.; Turski, P.; Levin, A.; Strother, C.; Mistretta, C.; Mackie, R.; Gehring, M.; Kubsad, S.; Kinsella, T. )

    1993-01-15

    Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquanitfy flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60 and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none. Early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery an flow parameters should be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning. A single diagnostic test may therefore be used for diagnosis, radiosurgical treatment planning, follow-up, and treatment selection by identifying patients likely to respond early to radiosurgical management.

  10. Combined multi-modal photoacoustic tomography, optical coherence tomography (OCT) and OCT angiography system with an articulated probe for in vivo human skin structure and vasculature imaging

    PubMed Central

    Liu, Mengyang; Chen, Zhe; Zabihian, Behrooz; Sinz, Christoph; Zhang, Edward; Beard, Paul C.; Ginner, Laurin; Hoover, Erich; Minneman, Micheal P.; Leitgeb, Rainer A.; Kittler, Harald; Drexler, Wolfgang

    2016-01-01

    Cutaneous blood flow accounts for approximately 5% of cardiac output in human and plays a key role in a number of a physiological and pathological processes. We show for the first time a multi-modal photoacoustic tomography (PAT), optical coherence tomography (OCT) and OCT angiography system with an articulated probe to extract human cutaneous vasculature in vivo in various skin regions. OCT angiography supplements the microvasculature which PAT alone is unable to provide. Co-registered volumes for vessel network is further embedded in the morphologic image provided by OCT. This multi-modal system is therefore demonstrated as a valuable tool for comprehensive non-invasive human skin vasculature and morphology imaging in vivo. PMID:27699106

  11. Multimodality evaluation of dural arteriovenous fistula with CT angiography, MR with arterial spin labeling, and digital subtraction angiography: case report.

    PubMed

    Alexander, Matthew; McTaggart, Ryan; Santarelli, Justin; Fischbein, Nancy; Marks, Michael; Zaharchuk, Greg; Do, Huy

    2014-01-01

    Dural arteriovenous fistulae (DAVF) are cerebrovascular lesions with pathologic shunting into the venous system from arterial feeders. Digital subtraction angiography (DSA) has long been considered the gold standard for diagnosis, but advances in noninvasive imaging techniques now play a role in the diagnosis of these complex lesions. Herein, we describe the case of a patient with right-side pulsatile tinnitus and DAVF diagnosed using computed tomography angiography, magnetic resonance with arterial spin labeling, and DSA. Implications for imaging analysis of DAVFs and further research are discussed.

  12. Computed Tomography Angiography Allows the Classification of the First Dorsal Metatarsal Arteries.

    PubMed

    Xu, Lin; Yang, Keqin; Wei, Pingou; Luo, Xiang; Mo, Yongjun; Liang, Xuquan; Lin, Han; Tan, Haitao; Mudgal, Chaitanya S

    2016-11-01

    Background Conventional angiography is an invasive technique. Submillimeter computed tomography angiography (CTA) has been shown to be an effective alternative for peripheral artery branches. This study aimed to assess the use of CTA to guide the choice and design of foot donor area for finger or thumb reconstruction. Methods This was a retrospective study of 79 patients who underwent finger or thumb reconstruction between January, 2011 and March, 2014. All these patients underwent preoperative CTA to determine the exact blood supply at the donor site. Preoperative imaging and intraoperative findings at the donor site were compared. Results Among the 79 patients (158 feet), 474 artery segments (dorsalis pedis artery [DPA], first dorsal metatarsal artery [FDMA], and toe web artery [TWA]) were evaluated using CTA. Image satisfaction rates of the vessels were 100.0 ± 0.0%, 89.2 ± 3.2%, and 60.1 ± 5.0% for DPA, FDMA, and TWA, respectively. Among the 158 feet, 90 were Gilbert type I (57.0%), 52 were Gilbert type II (32.9%), 13 were Gilbert type III (8.2%), and 3 were with poor visibility and could not be classified (1.9%). In all 79 patients, the CTA image of the FDMA was consistent with the intraoperative observations. All reconstructed fingers survived. Follow-up was available for 69 patients. After a 6- to 18-month follow-up, the reconstructed fingers and donor area recovered well, and the reconstructed fingers had strong holding power, without pain. Conclusion CTA can produce three-dimensional images for extremity arteries, allowing the preoperative assessment of blood supply and planning of donor site.

  13. [A man with vision problems after coronary angiography].

    PubMed

    Salomé, Mariet E; Jansen, Ben P W

    2015-01-01

    A 71-year-old man underwent a coronary angiography (CAG). Afterwards he experienced vision loss. Neurologic examination revealed bilateral cortical blindness. A cerebral CT-scan showed occipital hyperdensity, due to contrast accumulation and oedema. There was complete recovery of vision within 2 days. Transient cortical blindness after CAG is a rare complication of iodinated contrast agents.

  14. Myocardial Scar Detection by Standard CT Coronary Angiography

    PubMed Central

    Jeevarethinam, Anand; Venuraju, Shreenidhi; Mehta, Vishal Shahil; Atwal, Satvir; Raval, Usha; Rakhit, Roby; Davar, Joseph; Lahiri, Avijit

    2014-01-01

    We have described a myocardial infarct scar identified by a standard dual source CT coronary angiography (CTCA). We were able to detect the scar during the routine coronary assessment without contrast late enhancement and without additional radiation exposure. It is therefore feasible to assess chronic scar using a standard CTCA technique.

  15. High-speed lossless compression for angiography image sequences

    NASA Astrophysics Data System (ADS)

    Kennedy, Jonathon M.; Simms, Michael; Kearney, Emma; Dowling, Anita; Fagan, Andrew; O'Hare, Neil J.

    2001-05-01

    High speed processing of large amounts of data is a requirement for many diagnostic quality medical imaging applications. A demanding example is the acquisition, storage and display of image sequences in angiography. The functional performance requirements for handling angiography data were identified. A new lossless image compression algorithm was developed, implemented in C++ for the Intel Pentium/MS-Windows environment and optimized for speed of operation. Speeds of up to 6M pixels per second for compression and 12M pixels per second for decompression were measured. This represents an improvement of up to 400% over the next best high-performance algorithm (LOCO-I) without significant reduction in compression ratio. Performance tests were carried out at St. James's Hospital using actual angiography data. Results were compared with the lossless JPEG standard and other leading methods such as JPEG-LS (LOCO-I) and the lossless wavelet approach proposed for JPEG 2000. Our new algorithm represents a significant improvement in the performance of lossless image compression technology without using specialized hardware. It has been applied successfully to image sequence decompression at video rate for angiography, one of the most challenging application areas in medical imaging.

  16. Preduodenal portal vein in an adult--angiography and CT.

    PubMed

    Sasai, K; Sano, A; Nishizawa, S; Imanaka, K; Kuroda, Y

    1985-01-01

    We report on an adult case of preduodenal portal vein illustrated by computed tomography (CT) and angiography. These diagnostic modalities were initially performed to evaluate a coexisting pancreatic cancer. Contrast-enhanced CT demonstrated unusual positioning of the portal vein ventral to the duodenum. The superior mesenteric-portal vein, which was L-shaped and convexly caudad, strongly suggested this anomalous condition.

  17. Advances in post-mortem CT-angiography

    PubMed Central

    Grimm, J; Dominguez, A; Vanhaebost, J; Mangin, P

    2014-01-01

    Performing a post-mortem multidetector CT (MDCT) scan has already become routine in some institutes of forensic medicine. To better visualize the vascular system, different techniques of post-mortem CT-angiography have been explored, which can essentially be divided into partial- and whole-body angiography techniques. Probably the most frequently applied technique today is the so-called multiphase post-mortem CT-angiography (MPMCTA) a standardized method for investigating the vessels of the head, thorax and abdomen. Different studies exist, describing its use for medicolegal investigations, and its advantages as well as its artefacts and pitfalls. With the aim to investigate the performance of PMCTA and to develop and validate techniques, an international working group was created in 2012 called the “Technical Working Group Post-mortem Angiography Methods” (TWGPAM). Beyond its primary perspective, the goals of this group include creating recommendations for the indication of the investigation and for the interpretation of the images and to distribute knowledge about PMCTA. This article provides an overview about the different approaches that have been developed and tested in recent years and an update about ongoing research in this field. It will explain the technique of MPMCTA in detail and give an outline of its indications, application, advantages and limitations. PMID:24234582

  18. Costs and clinical outcomes for non-invasive versus invasive diagnostic approaches to patients with suspected in-stent restenosis.

    PubMed

    Min, James K; Hasegawa, James T; Machacz, Susanne F; O'Day, Ken

    2016-02-01

    This study compared costs and clinical outcomes of invasive versus non-invasive diagnostic evaluations for patients with suspected in-stent restenosis (ISR) after percutaneous coronary intervention. We developed a decision model to compare 2 year diagnosis-related costs for patients who presented with suspected ISR and were evaluated by: (1) invasive coronary angiography (ICA); (2) non-invasive stress testing strategy of myocardial perfusion imaging (MPI) with referral to ICA based on MPI; (3) coronary CT angiography-based testing strategy with referral to ICA based on CCTA. Costs were modeled from the payer's perspective using 2014 Medicare rates. 56 % of patients underwent follow-up diagnostic testing over 2 years. Compared to ICA, MPI (98.6 %) and CCTA (98.1 %) exhibited lower rates of correct diagnoses. Non-invasive strategies were associated with reduced referrals to ICA and costs compared to an ICA-based strategy, with diagnostic costs lower for CCTA than MPI. Overall 2-year costs were highest for ICA for both metallic as well as BVS stents ($1656 and $1656, respectively) when compared to MPI ($1444 and $1411) and CCTA. CCTA costs differed based upon stent size and type, and were highest for metallic stents >3.0 mm followed by metallic stents <3.0 mm, BVS < 3.0 mm and BVS > 3.0 mm ($1466 vs. $1242 vs. $855 vs. $490, respectively). MPI for suspected ISR results in lower costs and rates of complications than invasive strategies using ICA while maintaining high diagnostic performance. Depending upon stent size and type, CCTA results in lower costs than MPI.

  19. Costs and clinical outcomes for non-invasive versus invasive diagnostic approaches to patients with suspected in-stent restenosis

    PubMed Central

    Hasegawa, James T.; Machacz, Susanne F.; O’Day, Ken

    2015-01-01

    This study compared costs and clinical outcomes of invasive versus non-invasive diagnostic evaluations for patients with suspected in-stent restenosis (ISR) after percutaneous coronary intervention. We developed a decision model to compare 2 year diagnosis-related costs for patients who presented with suspected ISR and were evaluated by: (1) invasive coronary angiography (ICA); (2) non-invasive stress testing strategy of myocardial perfusion imaging (MPI) with referral to ICA based on MPI; (3) coronary CT angiography-based testing strategy with referral to ICA based on CCTA. Costs were modeled from the payer’s perspective using 2014 Medicare rates. 56 % of patients underwent follow-up diagnostic testing over 2 years. Compared to ICA, MPI (98.6 %) and CCTA (98.1 %) exhibited lower rates of correct diagnoses. Non-invasive strategies were associated with reduced referrals to ICA and costs compared to an ICA-based strategy, with diagnostic costs lower for CCTA than MPI. Overall 2-year costs were highest for ICA for both metallic as well as BVS stents ($1656 and $1656, respectively) when compared to MPI ($1444 and $1411) and CCTA. CCTA costs differed based upon stent size and type, and were highest for metallic stents >3.0 mm followed by metallic stents <3.0 mm, BVS < 3.0 mm and BVS > 3.0 mm ($1466 vs. $1242 vs. $855 vs. $490, respectively). MPI for suspected ISR results in lower costs and rates of complications than invasive strategies using ICA while maintaining high diagnostic performance. Depending upon stent size and type, CCTA results in lower costs than MPI. PMID:26335370

  20. Evaluating Polypoidal Choroidal Vasculopathy With Optical Coherence Tomography Angiography

    PubMed Central

    Wang, Min; Zhou, Yao; Gao, Simon S.; Liu, Wei; Huang, Yongheng; Huang, David; Jia, Yali

    2016-01-01

    Purpose We observed and analyzed the morphologic characteristics of polypoidal lesions and abnormal branching vascular network (BVN) in patients with polypoidal choroidal vasculopathy (PCV) by optical coherence tomography angiography (OCTA). Methods A retrospective observational case series was done of patients with PCV. All patients were scanned with a 70-kHz spectral-domain OCT system using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm to distinguish blood flow from static tissue. The OCTA images of these patients were compared to those from indocyanine green angiography (ICGA). Semiautomated segmentation was used to further analyze the polypoidal lesion and the BVN. Results We studied 13 eyes of 13 patients 51 to 69 years old. A total of 11 patients were treatment-naive. Two patients had multiple anti-VEGF injections and one underwent photodynamic therapy (PDT). Optical coherence tomography angiography was able to detect the BVN in all cases. Using cross-sectional OCTA, BVN locations were shown to be in the space between the RPE and Bruch's membrane. Using en face OCTA, the BVN vascular pattern could be shown more clearly than by ICGA. Polypoidal lesions showed high flow signals in different patterns in 12 cases in the outer retina slab. Using cross-sectional OCTA, the polyps were shown to be just below the top of the pigment epithelial detachment (PED). In one case, the polypoidal lesion was not detectable at the outer retina slab. Conclusions Optical coherence tomography angiography is a noninvasive imaging tool for detecting vascular changes in PCV. Branching vascular networks showed more clearly on OCTA than on ICGA. Polypoidal lesions had variable patterns on OCTA and were not always detected. The OCTA patterns of the polypoidal lesions and the BVN are helpful in understanding the pathology of PCV. PMID:27472276

  1. [Digital thermo-coronary angiography--development and validation of the method in comparison with conventional cine-coronary angiography].

    PubMed

    Mohr, F W; Grundfest, W; Litvack, F; Forrester, J; Matloff, J; Kirchhoff, P G

    1989-07-01

    We describe the technique-thermal coronary angiography (TCA)-for real-time assessment of coronary anatomy and flow. The goal of this study was to compare thermal coronary angiography to cine coronary angiography and to validate its value for detecting stenoses. We studied the exposed LAD both in beating and arrested hearts in 11 open-chest pigs by TCA and cine angiography. We used an AGA 782 Thermovision system combined with a TIC 8000 digital image processor providing coronary images with 0.1-0.2 mm spatial and 0.1 degrees C thermal resolution, and a CFR x-ray system. The coronary arteries were catheterized via the right carotid artery, using standard 5F catheters. The thermal camera was focused at a 1m-distance to the heart surface and the x-ray was angled to LAO position. We performed simultaneous thermal and cine angiography using Angiovist 370 at different temperatures (10-40 degrees C) and injection rates (1-2.5 ml/s). Different grades of stenoses were created by snares. Thermistor probe readings of the epimyocardium and the left atrial blood were performed to reference the thermal camera measurements. We obtained high resolution TCA images of both the coronaries and of the myocardial perfusion beds whenever there was greater than 4 degrees C difference between injectate and epicardial temperature. The TCA detection of stenoses as compared to cine angiography was 29/30 (96.6%) in arrested and 36/42 (85.7%) in beating hearts. Coronary occlusion produced immediate and dramatic perfusion defects as detected by TCA. TCAs were highly reproducible. Injection rate of 2 ml/s provided optimal thermal coronary images. Thermal angiograms of the LAD were sometimes affected by large crossing coronary veins, myocardial bridges, and excess of fat pretending nonexistent coronary stenosis. TCA is a highly sensitive and reproducible method as compared to standard coronary angiography and allows for detection of coronary stenoses. The image quality was best in arrested hearts.

  2. Three-dimensional spiral CT angiography in pancreatic surgical planning using non-tailored protocols: comparison with conventional angiography.

    PubMed

    Blomley, M J; Albrecht, T; Williamson, R C; Allison, D J

    1998-03-01

    The aim of this study was to investigate three-dimensional spiral computed tomography (3DCT) as an adjunct to routine pancreatic CT scanning, with particular regard to the identification of surgically important hepatic arterial anomalies, correlated with conventional visceral angiography. 32 patients underwent spiral CT scans prior to pancreatic surgery using established protocols. Oral contrast medium was used throughout. 150 ml of intravenous contrast medium was given at 3 ml s-1 with a 24 s spiral CT sequence starting 35 s after the start of infusion. Two protocols were employed, both with a pitch of 1:3 mm table feed/collimation (n = 17) and 5 mm table feed/collimation (n = 15). Overlapping (1 mm minimum) axial reformats were reconstructed. 3DCT shaded-surface displays of the visceral arteries were assessed for visceral arterial anomalies. Visceral angiography (n = 23) was independently correlated. Satisfactory 3D angiograms were performed in all but one patient, in whom the coeliac axis was missed. (i) 3 mm protocol: 3DCT (n = 17) showed three anomalous right hepatic arteries (ARHA), one trifurcation anomaly and one splenic artery with an aortic origin. Angiography (n = 11) confirmed these findings, although one patient with an ARHA did not have angiography. A left gastric arterial supply to the left liver was not detected. (ii) 5 mm protocol: 3DCT (n = 15) showed two cases of ARHA. While confirming these findings, angiography (n = 12) showed a third case of ARHA, in which the coeliac and superior mesenteric artery had very close origins. A left gastric supply to the left liver was also missed. It is concluded that satisfactory 3DCT is possible without changing existing scanning protocols, although narrow sections are required for the confident assessment of right hepatic arterial anomalies, and any left hepatic supply via the left gastric artery was poorly assessed in this series.

  3. MR-Guided PTA in Experimental Bilateral Rabbit Renal Artery Stenosis and MR Angiography Follow-Up Versus Histomorphometry

    SciTech Connect

    Le Blanche, Alain-Ferdinand; Rossert, Jerome; Wassef, Michel; Levy, Bernard; Bigot, Jean-Michel; Boudghene, Frank

    2000-09-15

    Purpose: To assess in vivo 1) MR-guided percutaneous transluminal renal angioplasty (PTRA) in experimental bilateral rabbit renal artery stenosis (RAS); 2) postprocedural follow-up by gadolinium-enhanced MR angiography versus histomorphometry.Methods: Fifteen male NZW rabbits of mean weight 4.0 kg (range 3.5-4.2 kg) underwent bilateral RAS induction by combined overdilation-deendothelialization with a gadolinium-filled balloon, passively MR-guided by the artifact of a 0.014-inch guidewire. After 4 weeks the rabbits were randomized into two groups: group A (n = 8) underwent right-sided PTRA for treatment of RAS, group B (n = 7) underwent left-sided PTRA. After another 4 weeks the rabbits were killed to assess by histomorphometry recurrent stenosis and contralateral induction injury stenosis lesions. Each step was preceded by gadolinium-enhanced three-dimensional MR angiography, and the cortex-to-aorta (C/A) signal intensity ratio was calculated.Results: RAS induction was successful in all cases. Fourteen arteries developed restenosis and 13 only initial stenosis. MR-guided PTRAs were feasible in 22 arteries (73%). For a successful catheterization of the ostium (20 arteries, 66% success rate), 10-25 steps were required. Five to eight steps were required for balloon localization and inflation for each PTRA. The restenosis effect was reflected by a 16% (12%-27%) decrease in C/A values on MR angiograms (p < 0.05).Conclusion: MR guidance and MR angiography represent a feasible, less invasive alternative for performing and assessing experimental PTRA in RAS.

  4. A prospective feasibility study of duplex ultrasound arterial mapping, digital-subtraction angiography, and magnetic resonance angiography in management of critical lower limb ischemia by endovascular revascularization.

    PubMed

    Lowery, A J; Hynes, N; Manning, B J; Mahendran, M; Tawfik, S; Sultan, S

    2007-07-01

    Duplex ultrasound arterial mapping (DUAM) allows precise evaluation of peripheral vascular disease (PVD). However, magnetic resonance angiography (MRA) and digital-subtraction angiography (DSA) are the diagnostic tools used most frequently prior to intervention. Our aim was to compare clinical pragmatism, hemodynamic outcomes, and cost-effectiveness when using DUAM alone compared to DSA or MRA as preoperative assessment tools for endovascular revascularization (EvR) in critical lower limb ischemia (CLI). From 2002 through 2005, 465 patients were referred with PVD. Of these, 199 had CLI and 137 required EvR. Preoperative diagnostic evaluation included DUAM (n = 41), DSA (n = 50), or MRA (n = 46). EvR was aortoiliac in 27% of cases and infrainguinal in 73%. Patients were assessed at day 1, 6 weeks, 3 months, and 6 months. Composite end points were relief of rest pain, ulcer/gangrene healing, and increase in perfusion pressure, as measured by ankle-brachial index (ABI) and digital pressures. Patency by DUAM, limb salvage, morbidity, mortality, length of stay, and cost-effectiveness were compared between groups using nonparametric t-test, analysis of variance, and Kaplan-Meier analysis. The three groups were comparable in terms of age, sex, comorbidity, and Society for Vascular Surgery/International Society of Cardiovascular Surgery clinical classification. Six-month mean improvement in ABI in the DUAM group was comparable to that in the DSA group (P = 0.25) and significantly better than that in the MRA group (P < 0.05). Six-month patency rates for the DUAM group were comparable to those in the DSA group (P = 0.68, relative risk [RR] = 0.74, 95% confidence interval [CI] 0.18-2.99) and superior to that in the MRA group (P = 0.022, RR = 0.255, 95% CI 0.09-0.71). Length of hospital stay was lower in the DUAM group compared with the DSA group (P < 0.0001) and the MRA group (P = 0.0003). The cost of DUAM is lower than that of both DSA and MRA. DUAM accurately identified the

  5. Current role of hybrid CT/angiography system compared with C-arm cone beam CT for interventional oncology

    PubMed Central

    Arai, Y; Inaba, Y; Inoue, M; Nishiofuku, H; Anai, H; Hori, S; Sakaguchi, H; Kichikawa, K

    2014-01-01

    Hybrid CT/angiography (angiography) system and C-arm cone beam CT provide cross-sectional imaging as an adjunct to angiography. Current interventional oncological procedures can be conducted precisely using these two technologies. In this article, several cases using a hybrid CT/angiography system are shown first, and then the advantages and disadvantages of the hybrid CT/angiography and C-arm cone beam CT are discussed with literature reviews. PMID:24968749

  6. Current role of hybrid CT/angiography system compared with C-arm cone beam CT for interventional oncology.

    PubMed

    Tanaka, T; Arai, Y; Inaba, Y; Inoue, M; Nishiofuku, H; Anai, H; Hori, S; Sakaguchi, H; Kichikawa, K

    2014-09-01

    Hybrid CT/angiography (angiography) system and C-arm cone beam CT provide cross-sectional imaging as an adjunct to angiography. Current interventional oncological procedures can be conducted precisely using these two technologies. In this article, several cases using a hybrid CT/angiography system are shown first, and then the advantages and disadvantages of the hybrid CT/angiography and C-arm cone beam CT are discussed with literature reviews.

  7. Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT)

    PubMed Central

    2013-01-01

    Background Coronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780). Methods/Design The analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest

  8. Generation and visualization of four-dimensional MR angiography data using an undersampled 3-D projection trajectory.

    PubMed

    Liu, Jing; Redmond, Michael J; Brodsky, Ethan K; Alexander, Andrew L; Lu, Aiming; Thornton, Francis J; Schulte, Michael J; Grist, Thomas M; Pipe, James G; Block, Walter F

    2006-02-01

    Time-resolved contrast-enhanced magnetic resonance (MR) angiography (CE-MRA) has gained in popularity relative to X-ray Digital Subtraction Angiography because it provides three-dimensional (3-D) spatial resolution and it is less invasive. We have previously presented methods that improve temporal resolution in CE-MRA while providing high spatial resolution by employing an undersampled 3-D projection (3D PR) trajectory. The increased coverage and isotropic resolution of the 3D PR acquisition simplify visualization of the vasculature from any perspective. We present a new algorithm to develop a set of time-resolved 3-D image volumes by preferentially weighting the 3D PR data according to its acquisition time. An iterative algorithm computes a series of density compensation functions for a regridding reconstruction, one for each time frame, that exploit the variable sampling density in 3D PR. The iterative weighting procedure simplifies the calculation of appropriate density compensation for arbitrary sampling patterns, which improve sampling efficiency and, thus, signal-to-noise ratio and contrast-to-noise ratio, since it is does not require a closed-form calculation based on geometry. Current medical workstations can display these large four-dimensional studies, however, interactive cine animation of the data is only possible at significantly degraded resolution. Therefore, we also present a method for interactive visualization using powerful graphics cards and distributed processing. Results from volunteer and patient studies demonstrate the advantages of dynamic imaging with high spatial resolution.

  9. High Resolution Ultrasound Superharmonic Perfusion Imaging: In Vivo Feasibility and Quantification of Dynamic Contrast-Enhanced Acoustic Angiography.

    PubMed

    Lindsey, Brooks D; Shelton, Sarah E; Martin, K Heath; Ozgun, Kathryn A; Rojas, Juan D; Foster, F Stuart; Dayton, Paul A

    2017-04-01

    Mapping blood perfusion quantitatively allows localization of abnormal physiology and can improve understanding of disease progression. Dynamic contrast-enhanced ultrasound is a low-cost, real-time technique for imaging perfusion dynamics with microbubble contrast agents. Previously, we have demonstrated another contrast agent-specific ultrasound imaging technique, acoustic angiography, which forms static anatomical images of the superharmonic signal produced by microbubbles. In this work, we seek to determine whether acoustic angiography can be utilized for high resolution perfusion imaging in vivo by examining the effect of acquisition rate on superharmonic imaging at low flow rates and demonstrating the feasibility of dynamic contrast-enhanced superharmonic perfusion imaging for the first time. Results in the chorioallantoic membrane model indicate that frame rate and frame averaging do not affect the measured diameter of individual vessels observed, but that frame rate does influence the detection of vessels near and below the resolution limit. The highest number of resolvable vessels was observed at an intermediate frame rate of 3 Hz using a mechanically-steered prototype transducer. We also demonstrate the feasibility of quantitatively mapping perfusion rate in 2D in a mouse model with spatial resolution of ~100 μm. This type of imaging could provide non-invasive, high resolution quantification of microvascular function at penetration depths of several centimeters.

  10. Fluorescein angiography in retrolental fibroplasia: experience from 1969-1977.

    PubMed

    Flynn, J T; Cassady, J; Essner, D; Zeskind, J; Merritt, J; Flynn, R; Williams, M J

    1979-10-01

    Acute proliferative retrolental fibroplasia (RLF) has been studied in premature infants employing a Zeiss fundus camera and fluorescein angiography. A total of 164 angiograms have been performed on 122 infants. At the present time, angiography is reserved for studying infants with peculiar or puzzling fundus pictures. A dose of 0.1-0.4 cc of 10% sodium fluoresceinate is employed, depending on the age and the weight of the baby. Fluorescein clearly outlines the major arteriovenous shunt in the retina, which is the hallmark of acute RLF. The shunt fills with fluorescein and leaks it profusely. On regression, a fine brush border of capillaries is seen in the region where the shunt previously had been located. Study of the population susceptible to RLF reveals it to be the smallest sickest babies in the premature nursery.

  11. Neuroradiologic applications of dynamic MR angiography at 3 T.

    PubMed

    Parmar, Hemant; Ivancevic, Marko K; Dudek, Nancy; Gandhi, Dheeraj; Geerts, Liesbeth; Hoogeveen, R; Mukherji, S K; Chenevert, Thomas L

    2009-02-01

    Four-dimensional time-resolved MR angiography (4D-MRA) using keyhole imaging techniques is a new method of performing contrastenhanced vascular imaging. Combining parallel imaging and keyhole imaging techniques, it is possible to obtain dynamic MRA scans up to 60 times faster, thereby achieving subsecond sampling of the contrast hemodynamics. Furthermore, imaging at 3 T gives higher signal, thus affording higher spatial resolution and allowing dynamic 3D MRA to approach the diagnostic performance of conventional digital subtraction angiography. This article presents the authors' clinical experience using 4D-MRA to evaluate various vascular abnormalities in the brain, spine, orbits, and neck at 3 T, demonstrates the imaging findings of this novel technique, and discusses its advantages and use in current neuroradiology practice.

  12. Towards the use of OCT angiography in clinical dermatology

    NASA Astrophysics Data System (ADS)

    Baran, Utku; Choi, Woo June; Wang, Ruikang K.

    2016-02-01

    Optical coherence tomography (OCT) is a popular imaging technique used in ophthalmology, and on the way to become clinically viable alternative in dermatology due to its capability of acquiring histopathology level images of in vivo tissue, noninvasively. In this study, we demonstrate the capabilities of OCT-based angiography (OMAG) in detecting high-resolution, volumetric structural and microvascular features of in vivo human skin with various conditions using a swept source OCT system that operates on a central wavelength of 1310 nm with an A-line rate of 100 kHz. OMAG images provide detailed in vivo visualization of microvasculature of abnormal human skin conditions from face, chest and belly. Moreover, the progress of wound healing on human skin from arm is monitored during longitudinal wound healing process. The presented results promise the clinical use of OCT angiography in treatment of prevalent cutaneous diseases within human skin, in vivo.

  13. Optical Coherence Tomography Angiography of the Optic Disc; an Overview

    PubMed Central

    Akil, Handan; Falavarjani, Khalil Ghasemi; Sadda, Srinivas R.; Sadun, Alfredo A.

    2017-01-01

    Different diseases of the optic disc may be caused by or lead to abnormal vasculature at the optic nerve head. Optical coherence tomography angiography (OCTA) is a novel technology that provides high resolution mapping of the retinal and optic disc vessels. Recent studies have shown the ability of OCTA to visualize vascular abnormalities in different optic neuropathies. In addition, quantified OCTA measurements were found promising for differentiating optic neuropathies from healthy eyes. PMID:28299012

  14. National Synchrotron Light Source angiography personnel protection interlock

    SciTech Connect

    Gmuer, N.; Larson, R.; Thomlinson, W.

    1992-06-01

    This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system.

  15. Vascular ultrasound studies for the non-invasive assessment of vascular flow and patency in experimental surgery in the pig.

    PubMed

    Osorio-da Cruz, S M; Aggoun, Y; Cikirikcioglu, M; Khabiri, E; Djebaili, K; Kalangos, A; Walpoth, B

    2009-10-01

    Vascular ultrasound is a reliable non-invasive tool used for the routine assessment of vascular flow and patency in human recipients. We describe the use at three different time points (immediately, 1 week and 4 weeks postsurgery) of ultrasound studies and its validation by angiographic studies in 37 swine undergoing carotid graft replacement. We calculated predictive values (>92%), sensitivity (>85%) and specificity (>92%) with high results at all time points. Ultrasound appeared as an accessible non-invasive technique, providing rapid, safe, repeatable and reliable results. It is an excellent alternative to angiography, avoiding risks inherent to invasive methods and therefore contributing to animal welfare.

  16. Optical coherence tomography angiography in pediatric choroidal neovascularization

    PubMed Central

    Veronese, Chiara; Maiolo, Chiara; Huang, David; Jia, Yali; Armstrong, Grayson W.; Morara, Mariachiara; Ciardella, Antonio P.

    2016-01-01

    Purpose To report two cases of pediatric choroidal neovascularization (CNV) and the associated neo-vascular and retinal findings identified on Optical Coherence Tomography Angiography (OCTA) imaging. Methods A 14-year-old boy with handheld laser-induced maculopathy-related CNV and a 13-year-old boy with idiopathic CNV were evaluated with visual acuity testing, slit-lamp exam, fundus photography, fluorescein angiography, indocyanine green angiography, spectral domain optical coherence tomography, and OCTA. Results Macular CNV were identified in both pediatric patients using OCTA imaging. The first case demonstrated a classic pediatric type II CNV with a “tree-like” pattern and a single vessel in-growth site, while the second case demonstrated a type I CNV with a “glomerular” pattern. Conclusion Distinct choroidal neovascular patterns were visualized in these two cases of pediatric CNV when compared to adult subtypes. OCTA is a noninvasive imaging modality capable of evaluating and characterizing pediatric CNV and their associated vascular patterns. PMID:27990495

  17. Calibration of optical coherence tomography angiography with a microfluidic chip

    NASA Astrophysics Data System (ADS)

    Su, Johnny P.; Chandwani, Rahul; Gao, Simon S.; Pechauer, Alex D.; Zhang, Miao; Wang, Jie; Jia, Yali; Huang, David; Liu, Gangjun

    2016-08-01

    A microfluidic chip with microchannels ranging from 8 to 96 μm was used to mimic blood vessels down to the capillary level. Blood flow within the microfluidic channels was analyzed with split-spectrum amplitude-decorrelation angiography (SSADA)-based optical coherence tomography (OCT) angiography. It was found that the SSADA decorrelation value was related to both blood flow speed and channel width. SSADA could differentiate nonflowing blood inside the microfluidic channels from static paper. The SSADA decorrelation value was approximately linear with blood flow velocity up to a threshold Vsat of 5.83±1.33 mm/s (mean±standard deviation over the range of channel widths). Beyond this threshold, it approached a saturation value Dsat. Dsat was higher for wider channels, and approached a maximum value Dsm as the channel width became much larger than the beam focal spot diameter. These results indicate that decorrelation values (flow signal) in capillary networks would be proportional to both flow velocity and vessel caliber but would be capped at a saturation value in larger blood vessels. These findings are useful for interpretation and quantification of clinical OCT angiography results.

  18. Mono-Energy Coronary Angiography with a Compact Synchrotron Source

    NASA Astrophysics Data System (ADS)

    Eggl, Elena; Mechlem, Korbinian; Braig, Eva; Kulpe, Stephanie; Dierolf, Martin; Günther, Benedikt; Achterhold, Klaus; Herzen, Julia; Gleich, Bernhard; Rummeny, Ernst; Noёl, Peter B.; Pfeiffer, Franz; Muenzel, Daniela

    2017-02-01

    X-ray coronary angiography is an invaluable tool for the diagnosis of coronary artery disease. However, the use of iodine-based contrast media can be contraindicated for patients who present with chronic renal insufficiency or with severe iodine allergy. These patients could benefit from a reduced contrast agent concentration, possibly achieved through application of a mono-energetic x-ray beam. While large-scale synchrotrons are impractical for daily clinical use, the technology of compact synchrotron sources strongly advanced during the last decade. Here we present a quantitative analysis of the benefits a compact synchrotron source can offer in coronary angiography. Simulated projection data from quasi-mono-energetic and conventional x-ray tube spectra is used for a CNR comparison. Results show that compact synchrotron spectra would allow for a significant reduction of contrast media. Experimentally, we demonstrate the feasibility of coronary angiography at the Munich Compact Light Source, the first commercial installation of a compact synchrotron source.

  19. Understanding the basic concepts of CO2 angiography

    NASA Astrophysics Data System (ADS)

    Zannoli, Romano; Bianchini, David; Rossi, Pier Luca; Caridi, James G.; Corazza, Ivan

    2016-11-01

    The diagnostic quality of carbon dioxide angiography depends both on optimal setting of radiological aspects (X-ray emission and image post-processing) and on the mechanical behavior of the injected gas bubbles. The gas behavior differs in large cavities (d > 12 mm), medium sized vessels (d > 6 mm), and small diameter vessels (d < 6 mm): to optimize the result the operator has to adapt his action to the physical rules governing the phenomenon in the particular situation. In most cases, it is impossible to fill a vessel completely with gas, and to obtain an adequate angiogram, the gas volume and injection pressure must be properly selected, patient's position must be adjusted and radiological image optimization algorithms, like Digital Subtraction Angiography (DSA) and stacking, must be applied. In this optimization process, the cultural and practical intervention of a medical physicist is fundamental. Obtaining a good quality CO2 angiogram is not only a matter of medical operator experience or radiological system performance, but involves matching a wide knowledge of medical physics to particular pathophysiological conditions and to unusual measurement tests. Most medical physicists are used to dealing mainly with radiological problems, and other physical aspects are considered beyond their interest. In CO2 angiography, non-radiological aspects strongly interfere with radiological issues and an optimal result can only be obtained by tackling the two simultaneously.

  20. Compton-backscattering x-ray source for coronary angiography

    SciTech Connect

    Blumberg, L.N.

    1992-12-01

    An X-ray source utilizing Compton-backscattered (CB) photons in a 75-MeV electron storage ring containing an infrared FEL is proposed for producing 33.17-keV X-rays (Iodine K-edge) for coronary angiography. The X-ray intensity into a 4-mrad cone is computed as 7.21 {times} 10{sup 14}/sec for a 500-mA electron beam colliding with 0.2-J/bunch, 3.22-{mu}m photons from an in-ring IR-FEL at the 353.21-MHz rate of a SLAC-PEP 500-kW RF system. The resultant average flux at the patient is 6.4 {times} 10{sup 7} photons/pixel/4-msec aver a 12-cm diameter circle at 3-m from the interaction point for the 0.5 {times}0.5-mm{sup 2} pixel size of the present Si(Li) array of the BNL-SMERF Angiography Facility. This flux is 2.1 times larger than obtains at SMERF at a comparable source-to-patient distance and over an area sufficient to encompass the entire coronary region. However, the X-Ray energy spread due to kinematics alone is 2.63-keV, a factor of 35 larger then SMERF, and presents the major difficulty for the digital subtraction angiography method (DSA) envisioned.

  1. Mono-Energy Coronary Angiography with a Compact Synchrotron Source

    PubMed Central

    Eggl, Elena; Mechlem, Korbinian; Braig, Eva; Kulpe, Stephanie; Dierolf, Martin; Günther, Benedikt; Achterhold, Klaus; Herzen, Julia; Gleich, Bernhard; Rummeny, Ernst; Noёl, Peter B.; Pfeiffer, Franz; Muenzel, Daniela

    2017-01-01

    X-ray coronary angiography is an invaluable tool for the diagnosis of coronary artery disease. However, the use of iodine-based contrast media can be contraindicated for patients who present with chronic renal insufficiency or with severe iodine allergy. These patients could benefit from a reduced contrast agent concentration, possibly achieved through application of a mono-energetic x-ray beam. While large-scale synchrotrons are impractical for daily clinical use, the technology of compact synchrotron sources strongly advanced during the last decade. Here we present a quantitative analysis of the benefits a compact synchrotron source can offer in coronary angiography. Simulated projection data from quasi-mono-energetic and conventional x-ray tube spectra is used for a CNR comparison. Results show that compact synchrotron spectra would allow for a significant reduction of contrast media. Experimentally, we demonstrate the feasibility of coronary angiography at the Munich Compact Light Source, the first commercial installation of a compact synchrotron source. PMID:28181544

  2. Computed Tomography Angiography in Microsurgery: Indications, Clinical Utility, and Pitfalls

    PubMed Central

    Lee, Gordon K.; Fox, Paige M.; Riboh, Jonathan; Hsu, Charles; Saber, Sepideh; Rubin, Geoffrey D.; Chang, James

    2013-01-01

    Objective: Computed tomographic angiography (CTA) can be used to obtain 3-dimensional vascular images and soft-tissue definition. The goal of this study was to evaluate the reliability, usefulness, and pitfalls of CTA in preoperative planning of microvascular reconstructive surgery. Methods: A retrospective review of patients who obtained preoperative CTA in preparation for planned microvascular reconstruction was performed over a 5-year period (2001–2005). The influence of CTA on the original operative plan was assessed for each patient, and CTA results were correlated to the operative findings. Results: Computed tomographic angiography was performed on 94 patients in preparation for microvascular reconstruction. In 48 patients (51%), vascular abnormalities were noted on CTA. Intraoperative findings correlated with CTA results in 97% of cases. In 42 patients (45%), abnormal CTA findings influenced the original operative plan, such as the choice of vessels, side of harvest, or nature of the reconstruction (local flap instead of free tissue transfer). Technical difficulties in performing CTA were encountered in 5 patients (5%) in whom interference from external fixation devices was the main cause. Conclusions: This large study of CTA obtained for preoperative planning of reconstructive microsurgery at both donor and recipient sites study demonstrates that CTA is safe and highly accurate. Computed tomographic angiography can alter the surgeon's reconstructive plan when abnormalities are noted preoperatively and consequently improve results by decreasing vascular complication rates. The use of CTA should be considered for cases of microsurgical reconstruction where the vascular anatomy may be questionable. PMID:24023972

  3. Compton-backscattering x-ray source for coronary angiography

    SciTech Connect

    Blumberg, L.N.

    1992-01-01

    An X-ray source utilizing Compton-backscattered (CB) photons in a 75-MeV electron storage ring containing an infrared FEL is proposed for producing 33.17-keV X-rays (Iodine K-edge) for coronary angiography. The X-ray intensity into a 4-mrad cone is computed as 7.21 [times] 10[sup 14]/sec for a 500-mA electron beam colliding with 0.2-J/bunch, 3.22-[mu]m photons from an in-ring IR-FEL at the 353.21-MHz rate of a SLAC-PEP 500-kW RF system. The resultant average flux at the patient is 6.4 [times] 10[sup 7] photons/pixel/4-msec aver a 12-cm diameter circle at 3-m from the interaction point for the 0.5 [times]0.5-mm[sup 2] pixel size of the present Si(Li) array of the BNL-SMERF Angiography Facility. This flux is 2.1 times larger than obtains at SMERF at a comparable source-to-patient distance and over an area sufficient to encompass the entire coronary region. However, the X-Ray energy spread due to kinematics alone is 2.63-keV, a factor of 35 larger then SMERF, and presents the major difficulty for the digital subtraction angiography method (DSA) envisioned.

  4. Registration of 3D+t coronary CTA and monoplane 2D+t X-ray angiography.

    PubMed

    Metz, Coert T; Schaap, Michiel; Klein, Stefan; Baka, Nora; Neefjes, Lisan A; Schultz, Carl J; Niessen, Wiro J; van Walsum, Theo

    2013-05-01

    A method for registering preoperative 3D+t coronary CTA with intraoperative monoplane 2D+t X-ray angiography images is proposed to improve image guidance during minimally invasive coronary interventions. The method uses a patient-specific dynamic coronary model, which is derived from the CTA scan by centerline extraction and motion estimation. The dynamic coronary model is registered with the 2D+t X-ray sequence, considering multiple X-ray time points concurrently, while taking breathing induced motion into account. Evaluation was performed on 26 datasets of 17 patients by comparing projected model centerlines with manually annotated centerlines in the X-ray images. The proposed 3D+t/2D+t registration method performed better than a 3D/2D registration method with respect to the accuracy and especially the robustness of the registration. Registration with a median error of 1.47 mm was achieved.

  5. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    SciTech Connect

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-09-15

    Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (P{sub KA}), skin surface entrance dose (K{sub AR}), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the P{sub KA.} 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median K{sub AR} = 581 mGy (374–876). Median P{sub KA} = 3908 uGym{sup 2} (2489–5865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median K{sub AR} = 1501 mGy (928–2224). Median P{sub KA} = 8736 uGym{sup 2} (5449–12,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.

  6. What Have We Learned from CONFIRM? Prognostic Implications from a Prospective Multicenter International Observational Cohort Study of Consecutive Patients Undergoing Coronary Computed Tomographic Angiography

    PubMed Central

    Otaki, Yuka; Arsanjani, Reza; Gransar, Heidi; Cheng, Victor Y.; Dey, Damini; Labounty, Troy; Lin, Fay Y.; Achenbach, Stephan; Al-Mallah, Mouaz; Budoff, Matthew J.; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Chinnaiyan, Kavitha; Chow, Benjamin J. W.; Delago, Augustin; Hadamitzky, Martin; Hausleiter, Joerg; Kaufmann, Philipp; Maffei, Erica; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison; Cury, Ricardo C.; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Berman, Daniel S.; Min, James K.

    2014-01-01

    Coronary computed tomographic angiography (CCTA) employing CT scanners of 64-detector rows or greater represents a novel noninvasive method for detection of coronary artery disease (CAD), providing excellent diagnostic information when compared to invasive angiography. In addition to its high diagnostic performance, prior studies have shown that CCTA can provide important prognostic information, although these prior studies have been generally limited to small cohorts at single centers. The Coronary CT Angiography EvaluatioN For clinical Outcomes: An InterRnational Multicenter Registry, or CONFIRM, is a large, prospective, multinational, dynamic observational cohort study of patients undergoing CCTA. This registry currently represents more than 32,000 consecutive adults suspected of having CAD who underwent ≥ 64–detector row CCTA at 12 centers in 6 countries between 2005 and 2009. Based on its large sample size and adequate statistical power, the data derived from CONFIRM registry has and will continue to provide key answers to many important topics regarding CCTA. Based on its multisite international national design, the results derived from CONFIRM should be considered as more generalizable than prior smaller single-center studies. This article summarizes the current status of several studies from CONFIRM registry. PMID:22689072

  7. Matching of projection imaging and tomographic imaging: application to digital subtracted angiography (DSA) and magnetic resonance angiography (MRA)

    NASA Astrophysics Data System (ADS)

    Vermandel, Maximilien; Kulik, Carine; Leclerc, Xavier; Rousseau, Jean; Vasseur, Christian

    2002-05-01

    This study proposes a new method for matching vascular imaging modalities without the use of external frame or external landmarks. We first perform a 3D reconstruction of a piece of the cerebral vascular tree using Magnetic Resonance Angiography (MRA). Then, this structure is projected on the Digital Subtracted Angiography (DSA) images until its best position and orientation are found. As the 3D structure is known in the MRA referential, this method enables us to match information from DSA and MRA. The complete matching of all the DSA images in many incidences and the MRA set have been obtained. For the DSA images, the epipolar constraint has been verified between all the incidences. This new approach in medical imaging brings a very original method, making easier and more efficient visualization and quantification of vascular information.

  8. Safety, efficacy, and cost of intraoperative indocyanine green angiography compared to intraoperative catheter angiography in cerebral aneurysm surgery.

    PubMed

    Hardesty, Douglas A; Thind, Harjot; Zabramski, Joseph M; Spetzler, Robert F; Nakaji, Peter

    2014-08-01

    Intraoperative angiography in cerebrovascular neurosurgery can drive the repositioning or addition of aneurysm clips. Our institution has switched from a strategy of intraoperative digital subtraction angiography (DSA) universally, to a strategy of indocyanine green (ICG) videoangiography with DSA on an as-needed basis. We retrospectively evaluated whether the rates of perioperative stroke, unexpected postoperative aneurysm residual, or parent vessel stenosis differed in 100 patients from each era (2002, "DSA era"; 2007, "ICG era"). The clip repositioning rate for neck residual or parent vessel stenosis did not differ significantly between the two eras. There were no differences in the rate of perioperative stroke or rate of false-negative studies. The per-patient cost of intraoperative imaging within the DSA era was significantly higher than in the ICG era. The replacement of routine intraoperative DSA with ICG videoangiography and selective intraoperative DSA in cerebrovascular aneurysm surgery is safe and effective.

  9. Attacking invasive grasses

    USGS Publications Warehouse

    Keeley, Jon E.

    2015-01-01

    In grasslands fire may play a role in the plant invasion process, both by creating disturbances that potentially favour non-native invasions and as a possible tool for controlling alien invasions. Havill et al. (Applied Vegetation Science, 18, 2015, this issue) determine how native and non-native species respond to different fire regimes as a first step in understanding the potential control of invasive grasses.

  10. Invasive species in agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural production of food, feed, fiber or fuel is a local human activity with global ecological impacts, including the potential to foster invasions. Agriculture plays an unusual role in biological invasions, in that it is both a source of non-indigenous invasive species (NIS) and especially s...

  11. Coronary artery plaque formation at coronary CT angiography: morphological analysis and relationship to hemodynamics.

    PubMed

    Enrico, Benedetta; Suranyi, Pal; Thilo, Christian; Bonomo, Lorenzo; Costello, Philip; Schoepf, U Joseph

    2009-04-01

    We aimed to demonstrate that coronary CT angiography (cCTA) can be used to non-invasively study the effect of hemodynamic factors in the pathophysiology of plaque formation. cCTA data of 73 patients were analyzed. All detected plaques were classified according to location (bifurcation, non-branching segment), configuration (eccentric, concentric), orientation (myocardial, lateral, epicardial side of the vessel wall), and composition (calcified, mixed, non-calcified). Bifurcation lesions were further characterized using the Medina classification. Of 382 plaques, 8.1% were in the LM, 46.3% in the LAD, 18.3% in the LCx, and 25.9% in the RCA. Also, 25.1% were completely calcified, 72.3% were mixed, and 2.6% were purely non-calcified. Of the plaques, 51.3% were bifurcation lesions. The most frequent (40%) Medina pattern was 1.1.0 (lesion starts before, extends beyond bifurcation, sparing the side branch). Eighty percent of plaques were eccentric. A significant (p < 0.01) majority (55%) were on the myocardial side, while 17.3% were lateral, and 27.7% epicardial. Of all non-calcified and mixed plaques, 45.1% (p < 0.01) were myocardial, whereas only 14.3% were lateral, 20.6% epicardial, and 19.9% concentric. We conclude that cCTA can non-invasively study the effect of vascular hemodynamics, such as turbulent flow (bifurcations) and low shear stress (myocardial vessel wall), on the distribution and composition of atherosclerotic plaque deposition.

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

    SciTech Connect

    Raza, Syed A.; Chughtai, Aamer R.; Wahba, Mona; Cowling, Mark G.; Taube, David; Wright, Andrew R.

    2004-01-15

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

  13. Visualization of micro-capillaries using optical coherence tomography angiography with and without adaptive optics.

    PubMed

    Salas, Matthias; Augustin, Marco; Ginner, Laurin; Kumar, Abhishek; Baumann, Bernhard; Leitgeb, Rainer; Drexler, Wolfgang; Prager, Sonja; Hafner, Julia; Schmidt-Erfurth, Ursula; Pircher, Michael

    2017-01-01

    The purpose of this work is to investigate the benefits of adaptive optics (AO) technology for optical coherence tomography angiography (OCTA). OCTA has shown great potential in non-invasively enhancing the contrast of vessels and small capillaries. Especially the capability of the technique to visualize capillaries with a lateral extension that is below the transverse resolution of the system opens unique opportunities in diagnosing retinal vascular diseases. However, there are some limitations of this technology such as shadowing and projection artifacts caused by overlying vasculature or the inability to determine the true extension of a vessel. Thus, the evaluation of the vascular structure and density based on OCTA alone can be misleading. In this paper we compare the performance of AO-OCT, AO-OCTA and OCTA for imaging retinal vasculature. The improved transverse resolution and the reduced depth of focus of AO-OCT and AO-OCTA greatly reduce shadowing artifacts allowing for a better differentiation and segmentation of different vasculature layers of the inner retina. The comparison is done on images recorded in healthy volunteers and in diabetic patients with distinct pathologies of the retinal microvasculature.

  14. Comparison of adaptive optics scanning light ophthalmoscopic fluorescein angiography and offset pinhole imaging.

    PubMed

    Chui, Toco Y P; Dubow, Michael; Pinhas, Alexander; Shah, Nishit; Gan, Alexander; Weitz, Rishard; Sulai, Yusufu N; Dubra, Alfredo; Rosen, Richard B

    2014-04-01

    Recent advances to the adaptive optics scanning light ophthalmoscope (AOSLO) have enabled finer in vivo assessment of the human retinal microvasculature. AOSLO confocal reflectance imaging has been coupled with oral fluorescein angiography (FA), enabling simultaneous acquisition of structural and perfusion images. AOSLO offset pinhole (OP) imaging combined with motion contrast post-processing techniques, are able to create a similar set of structural and perfusion images without the use of exogenous contrast agent. In this study, we evaluate the similarities and differences of the structural and perfusion images obtained by either method, in healthy control subjects and in patients with retinal vasculopathy including hypertensive retinopathy, diabetic retinopathy, and retinal vein occlusion. Our results show that AOSLO OP motion contrast provides perfusion maps comparable to those obtained with AOSLO FA, while AOSLO OP reflectance images provide additional information such as vessel wall fine structure not as readily visible in AOSLO confocal reflectance images. AOSLO OP offers a non-invasive alternative to AOSLO FA without the need for any exogenous contrast agent.

  15. Visualization of micro-capillaries using optical coherence tomography angiography with and without adaptive optics

    PubMed Central

    Salas, Matthias; Augustin, Marco; Ginner, Laurin; Kumar, Abhishek; Baumann, Bernhard; Leitgeb, Rainer; Drexler, Wolfgang; Prager, Sonja; Hafner, Julia; Schmidt-Erfurth, Ursula; Pircher, Michael

    2016-01-01

    The purpose of this work is to investigate the benefits of adaptive optics (AO) technology for optical coherence tomography angiography (OCTA). OCTA has shown great potential in non-invasively enhancing the contrast of vessels and small capillaries. Especially the capability of the technique to visualize capillaries with a lateral extension that is below the transverse resolution of the system opens unique opportunities in diagnosing retinal vascular diseases. However, there are some limitations of this technology such as shadowing and projection artifacts caused by overlying vasculature or the inability to determine the true extension of a vessel. Thus, the evaluation of the vascular structure and density based on OCTA alone can be misleading. In this paper we compare the performance of AO-OCT, AO-OCTA and OCTA for imaging retinal vasculature. The improved transverse resolution and the reduced depth of focus of AO-OCT and AO-OCTA greatly reduce shadowing artifacts allowing for a better differentiation and segmentation of different vasculature layers of the inner retina. The comparison is done on images recorded in healthy volunteers and in diabetic patients with distinct pathologies of the retinal microvasculature. PMID:28101412

  16. Use of pulmonary angiography for suspected pulmonary embolism: influence of scintigraphic diagnosis

    SciTech Connect

    Sostman, H.D.; Ravin, C.E.; Sullivan, D.C.; Mills, S.R.; Glickman, M.G.; Dorfman, G.S.

    1982-10-01

    The use of pulmonary angiography as related to ventilation-perfusion scintigraphy was studied at two teaching hospitals in 600 patients clinically suspected of having pulmonary embolism, using a combined prospective-retrospective approach. Sixty patients underwent angiography, 30 in each institution. A minority of patients in each scintigraphic diagnostic category underwent angiography, but the scintigraphic diagnosis had a major impact on the frequency of requests for angiography. Inconclusive scintigraphy was the principal reason for requesting angiography, although nearly half of patients in whom scintigraphic assessment was indecisive were managed without further diagnostic measures. Few patients in the low-probability and high-probability scintigraphic categories received angiography. This study also indicates that a substantial patient selection bias may exist in series that correlate scintigraphic and angiographic results.

  17. Persistent Primitive Trigeminal Artery That Mimics Persistent Primitive Otic Artery on Cerebral Angiography

    PubMed Central

    Lee, Kwangho; Park, Insung; Han, Jongwoo

    2016-01-01

    Persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis; on the other hand, persistent primitive otic artery (PPOA) is extremely rare. PPTA is often misdiagnosed as PPOA on cerebral angiography. We present a case of PPTA that mimicked PPOA on cerebral angiography. We further describe the utility of brain computed tomography angiography for differential diagnosis of PPTA from PPOA, together with a review of previous literature. PMID:27790403

  18. Does pelvic hematoma on admission computed tomography predict active bleeding at angiography for pelvic fracture?

    PubMed

    Brown, Carlos V R; Kasotakis, George; Wilcox, Alison; Rhee, Peter; Salim, Ali; Demetriades, Demetrios

    2005-09-01

    Pelvic angiography plays an increasing role in the management of pelvic fractures (PFs). Little has been written regarding the size of pelvic hematoma on admission computed tomography (CT) and how it relates to angiography results after PF. This is a retrospective review of trauma patients with PF who underwent an admission abdominal/pelvic CT scan and pelvic angiography from 2001 to 2003. CT pelvic hematoma was measured and classified as minimal or significant based on hematoma dimensions. Presence of a contrast blush on CT scan was also documented. Thirty-seven patients underwent an admission CT scan and went on to pelvic angiography. Of the 22 patients with significant pelvic hematoma, 73 per cent (n = 16) had bleeding at angiography. Fifteen patients had minimal pelvic hematoma, with 67 per cent (n = 10) showing active bleeding at angiography. In addition, five of six patients (83%) with no pelvic hematoma had active bleeding at angiography. Six patients had a blush on CT scan, with five of these (83%) having a positive angiogram. But, 22 of 31 (71%) patients with no blush on CT scan had bleeding at angiography. The absence of a pelvic hematoma or contrast blush should not alter indications for pelvic angiography, as they do not reliably exclude active pelvic bleeding.

  19. A Case Report of Thunderclap Headache with Sub-arachnoid Hemorrhage and Negative Angiography: A Review of Call-Fleming Syndrome and the use of Transcranial Dopplers in Predicting Morbidity

    PubMed Central

    Bittel, Brennen; Husmann, Kathrin

    2011-01-01

    Introduction: We present a case report in a patient with severe, recurrent, thunderclap with computed tomography (CT) evidence of subarachnoid blood and negative work-up for aneurysm. This case is an example of Call-Fleming syndrome with subarachnoid hemorrhage in which transcranial Doppler (TCD) was used for monitoring of cerebral vasoconstriction when angiography did not evidence vasoconstriction. We will review Call-Fleming syndrome and the utility of transcranial doppler imaging to assess cerebral vasoconstriction. Methods: A review of the current literature regarding diagnostics, treatment, and morbidity in Call-Fleming (reversible cerebral vasoconstriction syndrome) as well as a review of the data using transcranial color-coded sonography and transcranial doppler imaging to assess vasospasm in these cases. Results: The patient underwent computed tomography angiography (CTA) and venography (CTV), catheter angiography, lumbar puncture, and vasculitis work-up which were all negative. His magnetic resonance imaging (MRI) showed T2 weighted and fluid attenuation inversion recovery (FLAIR) hyper-intensities in the posterior frontal lobes as well as subarachnoid blood along bilateral occipital convexities. TCDs were obtained which showed elevated mean velocities. Conclusion: The use of bedside transcranial doppler imaging is a non-invasive means of assessing vasospasm in Call-Fleming syndrome; even in cases where angiography is negative. Determining the degree of vasospasm based on the data in subarachnoid hemorrhage, we are able to predict a patient’s risk of complications related to vasospasm including reversible posterior leukoencephalopathy and ischemic events. PMID:22518264

  20. Dual-Energy CT Angiography in Peripheral Arterial Occlusive Disease

    SciTech Connect

    Brockmann, Carolin Jochum, Susanne; Sadick, Maliha; Huck, Kurt; Ziegler, Peter; Fink, Christian; Schoenberg, Stefan O.; Diehl, Steffen J.

    2009-07-15

    We sought to study the accuracy of dual-energy computed tomographic angiography (DE-CTA) for the assessment of symptomatic peripheral arterial occlusive disease of the lower extremity by using the dual-energy bone removal technique compared with a commercially available conventional bone removal tool. Twenty patients underwent selective digital subtraction angiography and DE-CTA of the pelvis and lower extremities. CTA data were postprocessed with two different applications: conventional bone removal and dual-energy bone removal. All data were reconstructed and evaluated as 3D maximum-intensity projections. Time requirements for reconstruction were documented. Sensitivity, specificity, accuracy, and concordance of DE-CTA regarding degree of stenosis and vessel wall calcification were calculated. A total of 359 vascular segments were analyzed. Compared with digital subtraction angiography, sensitivity, specificity, and accuracy, respectively, of CTA was 97.2%, 94.1%, and 94.7% by the dual-energy bone removal technique. The conventional bone removal tool delivered a sensitivity of 77.1%, a specificity of 70.7%, and an accuracy of 72.0%. Best results for both postprocessing methods were achieved in the vascular segments of the upper leg. In severely calcified segments, sensitivity, specificity, and accuracy stayed above 90% by the dual-energy bone removal technique, whereas the conventional bone removal technique showed a substantial decrease of sensitivity, specificity, and accuracy. DE-CTA is a feasible and accurate diagnostic method in the assessment of symptomatic peripheral arterial occlusive disease. Results obtained by DE-CTA are superior to the conventional bone removal technique and less dependent on vessel wall calcifications.

  1. Quantitative Digital Subtraction Angiography in Pediatric Moyamoya Disease

    PubMed Central

    2015-01-01

    Moyamoya disease is a unique cerebrovascular disorder characterized by idiopathic progressive stenosis at the terminal portion of the internal carotid artery (ICA) and fine vascular network. The aim of this review is to present the clinical application of quantitative digital subtraction angiography (QDSA) in pediatric moyamoya disease. Using conventional angiographic data and postprocessing software, QDSA provides time-contrast intensity curves and then displays the peak time (Tmax) and area under the curve (AUC). These parameters of QDSA can be used as surrogate markers for the hemodynamic evaluation of disease severity and quantification of postoperative neovascularization in moyamoya disease. PMID:26180611

  2. Digital subtraction angiography: principles and pitfalls of image improvement techniques.

    PubMed

    Levin, D C; Schapiro, R M; Boxt, L M; Dunham, L; Harrington, D P; Ergun, D L

    1984-09-01

    The technology of imaging methods in digital subtraction angiography (DSA) is discussed in detail. Areas covered include function of the video camera in both interlaced and sequential scan modes, digitization by the analog-to-digital converter, logarithmic signal processing, dose rates, and acquisition of images using frame integration and pulsed-sequential techniques. Also discussed are various methods of improving image content and quality by both hardware and software modifications. These include the development of larger image intensifiers, larger matrices, video camera improvements, reregistration, hybrid subtraction, matched filtering, recursive filtering, DSA tomography, and edge enhancement.

  3. Fluorescein angiography: insight and serendipity a half century ago.

    PubMed

    Marmor, Michael F; Ravin, James G

    2011-07-01

    It has been 50 years since fluorescein angiography was developed as a clinical procedure by 2 medical students at Indiana University. The story of its discovery and the recognition of its value to ophthalmology involve a combination of insight and serendipity. Fluorescein had been in use clinically for more than half a century, but it took a pulmonary medicine laboratory to provide the stimulus for the development of flash and barrier filters that would make vascular photography practical. The first article was rejected by the ophthalmology literature, but several clinics heard about it and soon documented the enormous diagnostic value of the procedure.

  4. The conundrum of transient cortical blindness following coronary angiography.

    PubMed

    Borghi, Claudia; Saia, Francesco; Marzocchi, Antonio; Branzi, Angelo

    2008-10-01

    We report a case of transient cortical blindness that occurred after coronary angiography and angioplasty performed through the right radial artery. This is a very rare entity, the physiopathology of which remains largely speculative. The most likely mechanism appears to be the local disruption of the blood-brain barrier by the contrast agent, possibly favoured by predisposing factors, which may cause a direct neurotoxic effect. All contrast agents can be associated with this complication, which does not seem to be volume dependent. The outcome is generally favourable, with spontaneous return of sight within 24-48 h and no requirement for specific therapy. Recurrence has never been reported.

  5. Transient Global Amnesia After Cerebral Angiography With Iomeprol

    PubMed Central

    Tiu, Cristina; Terecoasă, Elena Oana; Grecu, Nicolae; Dorobăţ, Bogdan; Marinescu, Andreea Nicoleta; Băjenaru, Ovidiu Alexandru

    2016-01-01

    Abstract Transient global amnesia is now considered a very rare complication of cerebral angiography. Various etiological mechanisms have been suggested to account for this complication, but no consensus has been reached yet. This case report documents one of the few reported cases of cerebral angiography-related transient global amnesia associated with magnetic resonance imaging (MRI) evidence of unilateral hippocampal ischemia, most probably as a consequence of a transient reduction in regional hippocampal blood flow. However, the possibility of a direct neurotoxic effect of the nonionic contrast media Iomeprol on the Cornu ammonis – field 1 neurons cannot be firmly ruled out. We describe the case of a 54-year-old woman admitted to our department for left upper limb weakness with acute onset 8 days before. The brain computed tomography (CT) scan performed at admission revealed subacute ischemic lesions in the right watershed superficial territories and a right thalamic lacunar infarct. Diagnostic digital subtraction cerebral angiography was performed 4 days after admission with the nonionic contrast media Iomeprol. A few minutes after completion of the procedure, the patient developed symptoms suggestive for transient global amnesia. The brain MRI performed 22 hours after the onset of symptoms demonstrated increased signal within the lateral part of the right hippocampus on the diffusion-weighted imaging (DWI) sequences, associated with a corresponding reduction in the apparent diffusion coefficient (ADC) and increased signal on the fluid-attenuated inversion recovery (FLAIR) sequences, consistent with acute hippocampal ischemia and several T2/FLAIR hyperintensities in the right watershed superficial territories and in the right thalamus, corresponding to the lesions already identified on the CT scan performed at admission. A follow-up MRI, performed 2 months later, demonstrated the disappearance of the increased signal within the right hippocampus on the DWI

  6. Conventional Coronary Angiography Induced Takotsubo Cardiomyopathy Complicated with Cardiac Tamponade

    PubMed Central

    Kang, Min Gyu; Kim, Kye-Hwan; Koh, Jin-Sin; Jeong, Young-Hoon; Hwang, Jin-Yong

    2017-01-01

    Takotsubo cardiomyopathy (TCM) is a transient left ventricular dysfunction that typically occurs after emotional or physical stress. TCM has a benign prognosis and serious complications are uncommon. However, though very rarely reported, cardiac tamponade has occurred on some occasions. We hereby report the case of a 70-year-old woman who underwent coronary angiography with an ergonovine provocation test to evaluate recurrent chest pain and was readmitted 7 days later presenting with TCM, followed by left ventricular outflow tract obstruction and cardiac tamponade.

  7. Automated detection of dilated capillaries on optical coherence tomography angiography

    PubMed Central

    Dongye, Changlei; Zhang, Miao; Hwang, Thomas S.; Wang, Jie; Gao, Simon S.; Liu, Liang; Huang, David; Wilson, David J.; Jia, Yali

    2017-01-01

    Automated detection and grading of angiographic high-risk features in diabetic retinopathy can potentially enhance screening and clinical care. We have previously identified capillary dilation in angiograms of the deep plexus in optical coherence tomography angiography as a feature associated with severe diabetic retinopathy. In this study, we present an automated algorithm that uses hybrid contrast to distinguish angiograms with dilated capillaries from healthy controls and then applies saliency measurement to map the extent of the dilated capillary networks. The proposed algorithm agreed well with human grading. PMID:28271005

  8. Peripheral MR Angiography of Klippel-Trenaunay Syndrome

    SciTech Connect

    Fontana, Alessandro; Olivetti, Lucio

    2004-09-15

    Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disease of unknown etiology that affects one or more limbs. It is characterized clinically by three physical findings (the so-called triad): port-wine stain hemangioma, hypertrophy of the bony and/or soft tissue, and varicose veins. A review of the medical literature in 1999 revealed about 1,000 case studies. We present here the case of a patient with clinical diagnosis of KTS studied using peripheral magnetic resonance angiography.

  9. Congenital left ventricular aneurysm diagnosed by spiral CT angiography

    SciTech Connect

    Beregi, J.P.; Coulette, J.M.; Ducloux, G.

    1996-05-01

    We report a rare case of congenital left ventricular aneurysm, diagnosed by spiral CT angiography. Despite 1 s time acquisition, spiral CT, with adequate acquisition parameters and bolus injection of contrast medium, produced sufficiently good images to permit visualization of the aneurysm. Subsequently, reconstructions (shaded surface display and multiplanar reformation) were performed to demonstrate the relationship of the aneurysm with the remainder of the left ventricle, the wide neck of the aneurysm, and the absence of contractility, therein permitting differentiation from a congenital diverticulum. 6 refs., 3 figs.

  10. Application of image processing techniques to gamma-angiography.

    PubMed

    Romary, D; Lerallut, J F; Fontenier, G

    1985-10-01

    Different image processing techniques have been tested and compared on data derived from gamma-angiography images to detect the boundary of the left ventricle. The method involves a preprocessing step, followed by the edge detection itself. The best preprocessing is a nonlinear "variant" filtering, where each pixel is replaced by the average of the 3 X 3 neighborhood having the smallest variance. The edge detector giving the best contour is a Sobel operator. A second-order high-pass Butterworth filter also provides a good segmentation.

  11. Choriocapillaris evaluation in choroideremia using optical coherence tomography angiography

    PubMed Central

    Gao, Simon S.; Patel, Rachel C.; Jain, Nieraj; Zhang, Miao; Weleber, Richard G.; Huang, David; Pennesi, Mark E.; Jia, Yali

    2016-01-01

    The choriocapillaris plays an important role in supporting the metabolic demands of the retina. Studies of the choriocapillaris in disease states with optical coherence tomography angiography (OCTA) have proven insightful. However, image artifacts complicate the identification and quantification of the choriocapillaris in degenerative diseases such as choroideremia. Here, we demonstrate a supervised machine learning approach to detect intact choriocapillaris based on training with results from an expert grader. We trained a random forest classifier to evaluate en face structural OCT and OCTA information along with spatial image features. Evaluation of the trained classifier using previously unseen data showed good agreement with manual grading. PMID:28101400

  12. 64-Slice Computed Tomographic Angiography for the Diagnosis of Intermediate Risk Coronary Artery Disease

    PubMed Central

    2010-01-01

    Executive Summary In July 2009, the Medical Advisory Secretariat (MAS) began work on Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease (CAD), an evidence-based review of the literature surrounding different cardiac imaging modalities to ensure that appropriate technologies are accessed by patients suspected of having CAD. This project came about when the Health Services Branch at the Ministry of Health and Long-Term Care asked MAS to provide an evidentiary platform on effectiveness and cost-effectiveness of non-invasive cardiac imaging modalities. After an initial review of the strategy and consultation with experts, MAS identified five key non-invasive cardiac imaging technologies for the diagnosis of CAD. Evidence-based analyses have been prepared for each of these five imaging modalities: cardiac magnetic resonance imaging, single photon emission computed tomography, 64-slice computed tomographic angiography, stress echocardiography, and stress echocardiography with contrast. For each technology, an economic analysis was also completed (where appropriate). A summary decision analytic model was then developed to encapsulate the data from each of these reports (available on the OHTAC and MAS website). The Non-Invasive Cardiac Imaging Technologies for the Diagnosis of Coronary Artery Disease series is made up of the following reports, which can be publicly accessed at the MAS website at: www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html Single Photon Emission Computed Tomography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Stress Echocardiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Stress Echocardiography with Contrast for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis 64-Slice Computed Tomographic Angiography for the Diagnosis of Coronary Artery Disease: An Evidence-Based Analysis Cardiac

  13. Computed Tomographic Angiography as an Adjunct to Digital Subtraction Angiography for the Pre-Operative Assessment of Cerebral Aneurysms

    PubMed Central

    Farsad, Khashayar; Mamourian, Alexander C; Eskey, Clifford J; Friedman, Jonathan A

    2009-01-01

    Objectives: Computerized tomographic angiography (CTA) has emerged as a valuable diagnostic tool for the management of patients with cerebrovascular disease. The use of CTA in lieu of, or as an adjunct to, conventional cerebral angiography in the management of cerebral aneurysms awaits further experience. In this study, we evaluated the role of CTA specifically for the pre-operative assessment and planning of cerebral aneurysm surgery. Patients and Methods: We reviewed the relevant neuroimaging of all patients treated at Dartmouth Hitchcock Medical Center between January, 2001 and December, 2004 with a diagnosis of cerebral aneurysm and diagnostic evaluation with both CTA and conventional digital subtraction angiography (DSA) using standard imaging protocols. 32 patients underwent both CTA and DSA during the study period for a total of 36 aneurysms. Images were independently re-assesed by two neurosurgeons for information valuable for pre-operative surgical planning. Results: In 26 of 36 aneurysms (72%), the CTA was felt to provide the best image quality in defining the morphology of the aneurysm. In 14 aneurysms (39%), CTA provided clinically valuable anatomic detail not demonstrated on DSA, largely due to better visualization of parent and perforating vessel relationships at the aneurysm neck. There were no instances where a lesion was seen on DSA but missed on CTA. The DSA was of most clinical value in determining flow dynamics, such as the arterial supply of an anterior communicating artery aneurysm and distal anterior cerebral branches via the two A1 segments. Conclusion: CTA with three-dimensional reconstructions is a valuable adjunct to the preoperative evaluation of cerebral aneurysms. We advocate routine use of CTA in all patients in whom surgical aneurysm repair is planned, even when DSA has already been performed. PMID:19452029

  14. Animal experiments by K-edge subtraction angiography by using SR (abstract)

    NASA Astrophysics Data System (ADS)

    Anno, I.; Akisada, M.; Takeda, T.; Sugishita, Y.; Kakihana, M.; Ohtsuka, S.; Nishimura, K.; Hasegawa, S.; Takenaka, E.; Hyodo, K.; Ando, M.

    1989-07-01

    Ischemic heart disease is one of the most popular and lethal diseases for aged peoples in the world, and is usually diagnosed by transarterial selective coronary arteriography. However, it is rather invasive and somewhat dangerous, so that the selective coronary arteriography is not feasible for prospective screening of coronary occlusive heart disease. Conventional digital subtraction angiography (DSA) is widely known as a relatively noninvasive and useful technique is making a diagnosis of arterial occlusive disease, especially in making the diagnosis of ischemic heart disease. Conventional intravenous subtraction angiography by temporal subtraction, however, has several problems when applying to the moving objects. Digital subtraction method using high-speed switching above and below the K edge could be the ideal approach to this solution. We intend to make a synchrotron radiation digital K-edge subtraction angiography in the above policy, and to apply it to the human coronary ischemic disease on an outpatient basis. The principles and experimental systems have already been described in detail by our coworkers. Our prototype experimental system is situated at the AR (accumulation ring) for TRISTAN project of high energy physics. The available beam size is 70 mm by 120 mm. The electron energy of AR is 6.5 GeV and average beam current is approximately 10 mA. This paper will show the animal experiments of our K-edge subtraction system, and discuss some problems and technical difficulties. Three dogs, weighing approximately 15 kg, were examined to evaluate the ability of our prototype synchrotron radiation DSA unit, that we are now constructing. The dogs were anaesthetized with pentobarbital sodium, intravenously (30 mg/kg). Six french-sized (1.52 mm i.d.) pigtail catheter with multiple side holes were introduced via the right femoral vein into the right atrium by the cutdown technique under conventional x-ray fluoroscopic control. Respiration of the dogs was

  15. Virtual dye angiography: flow visualization for MRI-guided interventions.

    PubMed

    George, Ashvin K; Faranesh, Anthony Z; Ratnayaka, Kanishka; Derbyshire, J Andrew; Lederman, Robert J; Hansen, Michael S

    2012-04-01

    In magnetic resonance imaging-guided cardiovascular interventional procedures, it is valuable to be able to visualize blood flow immediately and interactively in selected regions. In particular, it is useful to assess normal or pathological communications between specific heart chambers and vessels. Phase-contrast velocity mapping is not suitable for this purpose as it requires too much data and is not capable of determining directly if blood originating in one location travels to a nearby location. This article presents a novel flow visualization method called virtual dye angiography that enables visualization of blood flow analogous to selective catheter angiography. The method uses two-dimensional radio frequency pulses to achieve interactive, intermittent, targeted saturation of a localized region of the blood pool. The flow of the saturated spins is observed directly on real-time images or, in an enhanced manner, using ECG synchronized background subtraction. The modular nature of the technique allows for easy and seamless integration into a real-time, interactive imaging system with minimal overhead. We present initial results in animals and in a healthy human volunteer.

  16. Clinical application of digital indocyanine green angiography in choroidal neurofibromatosis.

    PubMed

    Rescaldani, C; Nicolini, P; Fatigati, G; Bottoni, F G

    1998-01-01

    Indocyanine green angiography (ICGA) was used to investigate 2 cases of type 1 systemic neurofibromatosis that had appeared at birth with café-au-lait skin spots, gradually developing into multiple cutaneous neurofibromas. Patients underwent periodical visual acuity examinations, the fundus was checked and fluorescein angiography (FA) was done; all findings appeared extremely stable. In 1995 these 2 patients underwent ICGA to check for pathological choroidal involvement. In both cases the initial examination stages showed multiple extensive areas of hypofluorescence, their morphology and extension coinciding with the retinal pigment epithelium (RPE) lesions shown by FA and by ophthalmoscopic examination. In later stages the hypofluorescent areas became smaller, generally shrinking to small isolated dots in the middle of the original areas. These initially hypofluorescent areas appeared to be due to slow focal choroidal filling caused by deep alterations to the walls of the choroidal arterioles induced by the disease. Chronic hypoperfusion of the choriocapillaris results in impairment of the overlying RPE, causing it to atrophy. The late hypofluorescent areas could be either persistent nonperfused lobules of choriocapillaris or neurofibromatose choroidal nodules. ICGA examination showed that the FA lesions described in the literature as choroidal nodules are in fact alterations to the RPE secondary to areas of hypoperfusion in the choriocapillaris.

  17. Safe ex vivo coronary angiography with isosmotic contrast agent.

    PubMed

    Schmit, D B; Kern, J A; Mauney, M C; Kron, I L; Tribble, C G

    1996-08-01

    Plain-film coronary angiography of the cardiac explant on the operating table should be considered when conventional cardiac catheterization is desired but unavailable. We compared the effects of three contrast solutions on cold-preserved, isolated guinea pig hearts. Hearts were excised, perfused for 30 minutes, and arrested with Plegisol solution at 7 degree C. Twenty minutes after arrest, experimental hearts were perfused with one of three solutions: hyperosmolar Hexabrix solution (n = 6), hyperosmolar Renografin-76 solution (n = 6), or diluted, isosmotic Omnipaque solution (n = 8). The hearts were flushed with cold Plegisol solution 5 minutes later. Control hearts received no contrast during arrest (n = 9). The hearts were reperfused after 1 hour of arrest, and coronary blood flow (in millimeters per minute), left ventricular developed pressure (in millimeters of mercury), and rate of developed pressure (in millimeters of mercury per second) were measured. Endothelium-dependent smooth muscle relaxation to bradykinin administration and endothelium-independent relaxation to sodium nitroprusside administration were also assessed. No significant difference in myocardial or endothelial function was noted between control hearts and hearts perfused with Omnipaque solution. Hearts perfused with Renografin solution or Hexabrix solution, however, were found to have significantly impaired endothelial and myocardial function. We conclude that an isosmotic contrast solution should be used for ex vivo coronary angiography in cold-preserved hearts to avoid impairment of endothelial and myocardial function.

  18. Equilibrium radionuclide gated angiography in patients with tricuspid regurgitation

    SciTech Connect

    Handler, B.; Pavel, D.G.; Pietras, R.; Swiryn, S.; Byrom, E.; Lam, W.; Rosen, K.M.

    1983-01-15

    Equilibrium gated radionuclide angiography was performed in 2 control groups (15 patients with no organic heart disease and 24 patients with organic heart disease but without right- or left-sided valvular regurgitation) and in 9 patients with clinical tricuspid regurgitation. The regurgitant index, or ratio of left to right ventricular stroke counts, was significantly lower in patients with tricuspid regurgitation than in either control group. Time-activity variation over the liver was used to compute a hepatic expansion fraction which was significantly higher in patients with tricuspid regurgitation than in either control group. Fourier analysis of time-activity variation in each pixel was used to generate amplitude and phase images. Only pixels with values for amplitude at least 7% of the maximum in the image were retained in the final display. All patients with tricuspid regurgitation had greater than 100 pixels over the liver automatically retained by the computer. These pixels were of phase comparable to that of the right atrium and approximately 180 degrees out of phase with the right ventricle. In contrast, no patient with no organic heart disease and only 1 of 24 patients with organic heart disease had any pixels retained by the computer. In conclusion, patients with tricuspid regurgitation were characterized on equilibrium gated angiography by an abnormally low regurgitant index (7 of 9 patients) reflecting increased right ventricular stroke volume, increased hepatic expansion fraction (7 of 9 patients), and increased amplitude of count variation over the liver in phase with the right atrium (9 of 9 patients).

  19. Dynamic CT head phantom for perfusion and angiography studies

    NASA Astrophysics Data System (ADS)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  20. Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging

    SciTech Connect

    Baillet, G.Y.; Mena, I.G.; Kuperus, J.H.; Robertson, J.M.; French, W.J.

    1989-01-01

    Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

  1. Assessment of vessel diameters for MR brain angiography processed images

    NASA Astrophysics Data System (ADS)

    Moraru, Luminita; Obreja, Cristian-Dragos; Moldovanu, Simona

    2015-12-01

    The motivation was to develop an assessment method to measure (in)visible differences between the original and the processed images in MR brain angiography as a method of evaluation of the status of the vessel segments (i.e. the existence of the occlusion or intracerebral vessels damaged as aneurysms). Generally, the image quality is limited, so we improve the performance of the evaluation through digital image processing. The goal is to determine the best processing method that allows an accurate assessment of patients with cerebrovascular diseases. A total of 10 MR brain angiography images were processed by the following techniques: histogram equalization, Wiener filter, linear contrast adjustment, contrastlimited adaptive histogram equalization, bias correction and Marr-Hildreth filter. Each original image and their processed images were analyzed into the stacking procedure so that the same vessel and its corresponding diameter have been measured. Original and processed images were evaluated by measuring the vessel diameter (in pixels) on an established direction and for the precise anatomic location. The vessel diameter is calculated using the plugin ImageJ. Mean diameter measurements differ significantly across the same segment and for different processing techniques. The best results are provided by the Wiener filter and linear contrast adjustment methods and the worst by Marr-Hildreth filter.

  2. [Invasive and minimally invasive hemodynamic monitoring].

    PubMed

    Hansen, Matthias

    2016-10-01

    Advanced hemodynamic monitoring is necessary for adequate management of high-risk patients or patients with derangement of circulation. Studies demonstrate a benefit of early goal directed therapy in unstable cardiopulmonary situations. In these days we have different possibilities of minimally invasive or invasive hemodynamic monitoring. Minimally invasive measurements like pulse conture analysis or pulse wave analysis being less accurate under some circumstances, however only an artery catheter is needed for cardiac output monitoring. Pulmonary artery, transpulmonary thermodilution and lithium dilution technology have acceptable accuracy in cardiac output measurement. For therapy of unstable circulation there are additionally parameters to obtain. The pulmonary artery catheter is the device with the largest rate of complications, used by a trained crew and with a correct indication, his use is unchained justified.

  3. Evaluation of Coronary Artery Disease Using Myocardial Elastography with Diverging Wave Imaging: Validation against Myocardial Perfusion Imaging and Coronary Angiography.

    PubMed

    Grondin, Julien; Waase, Marc; Gambhir, Alok; Bunting, Ethan; Sayseng, Vincent; Konofagou, Elisa E

    2017-02-28

    Myocardial elastography (ME) is an ultrasound-based technique that can image 2-D myocardial strains. The objectives of this study were to illustrate that 2-D myocardial strains can be imaged with diverging wave imaging and differ, on average, between normal and coronary artery disease (CAD) patients. In this study, 66 patients with symptoms of CAD were imaged with myocardial elastography before a nuclear stress test or an invasive coronary angiography. Radial cumulative strains were estimated in all patients. The end-systolic radial strain in the total cross section of the myocardium was significantly higher in normal patients (17.9 ± 8.7%) than in patients with reversible perfusion defect (6.2 ± 9.3%, p < 0.001) and patients with significant (-0.9 ± 7.4%, p < 0.001) and non-significant (3.7 ± 5.7%, p < 0.01) lesions. End-systolic radial strain in the left anterior descending, left circumflex and right coronary artery territory was found to be significantly higher in normal patients than in CAD patients. These preliminary findings indicate that end-systolic radial strain measured with ME is higher on average in healthy persons than in CAD patients and that ME has the potential to be used for non-invasive, radiation-free early detection of CAD.

  4. Clinical experience of Hokkaido University-PACS and FCR-angiography.

    PubMed

    Terae, S; Hawkin, S; Sato, Y; Kikuchi, Y; Abe, S; Miyasaka, K

    1994-05-01

    Three years' experience with Hokkaido University-PACS (HU-PACS) is reported. In particular, this paper describes the suitability of FCR-angiography for HU-PACS, which has been in clinical use since March 1991. Image quality of FCR-arteriograms was evaluated in the head-and-face region and the abdominal region independently. The image quality in both regions was excellent. Quality of transferred images to image workstation for HU-PACS with 10:1 data compression was also evaluated, and no appreciable image degradation or loss of information was found in the transferred images. There was no significant difference in the examination time required for one patient in abdominal angiography between conventional angiography and FCR-angiography. In summary, FCR-angiography is suitable for HU-PACS as its image acquisition modality.

  5. Comparison of computed tomographic angiography and noncontrast magnetic resonance angiography in preoperative evaluation of living renal donors

    PubMed Central

    Patil, Abhijit Dnyandeo; Shailage, K.; Nadarajah, Jeyaseelan; Harigovind, P.; Mohan, R. Krishna

    2017-01-01

    Introduction: The computed tomographic angiography (CTA) renal donor protocol is an established method of preoperative renal vascular pedicle evaluation in prospective renal donors. However, CTA is associated with significant radiation exposure and intravenous contrast administration. The newer noncontrast-enhanced magnetic resonance angiography (NCE-MRA) techniques, especially arterial spin labeling (ASL) with steady-state free precession (SSFP) hold promise as an effective alternative. We prospectively compared CTA with NCE MRA for accuracy in the evaluation of renal arterial anatomy in prospective renal donors. Methods: A total of 43 subjects underwent CTA followed by NCE MRA in a prospective comparative study. The number of renal arteries and early branching of renal arteries were noted in both kidneys in all subjects. Intermodality agreement was calculated using “K” (Kappa) statistics and 95% confidence interval for both modalities. Results: A total of 63 single, 21 double, and 2 triple arteries were detected in 43 subjects on CTA. CTA showed an early branch in 17 kidneys. NCE MRAshowed 64 single arteries, 20 double arteries, and 2 triple arteries. A total of 14 kidneys showed an early branch. Unweighted Kappa statistic of agreement between CTA and NCE MRA for number of renal arteries and for frequency of early branching was 0.9707 and 0.8822, respectively. Conclusions: The newer NCE MRA techniques such as ASL with SSFP among others are potential alternatives for CTA, in the evaluation of prospective renal donors. PMID:28197027

  6. Computed tomography angiography versus digital subtraction angiography in vascular mapping for planning of microsurgical reconstruction of the mandible.

    PubMed

    Lell, Michael; Tomandl, Bernd F; Anders, Katharina; Baum, Ulrich; Nkenke, Emeka

    2005-08-01

    The aim of this work was to compare the potential of computed tomography angiography (CTA) with that of digital subtraction angiography (DSA) in vascular mapping of the external carotid artery (ECA) branches for planning of microvascular reconstructions of the mandible with osteomyocutaneous flaps. In 15 patients CTA and DSA were performed prior to surgery. Selective common carotid angiograms were acquired in two projection for both sides of the neck. Sixteen-slice spiral computed tomography was performed with a dual-phase protocol, using the arterial phase images for 3D CTA reconstruction. Thin-slab maximum intensity projections and volume rendering were employed for postprocessing of CTA data. The detectability of the different ECA branches in CTA and DSA was evaluated by two examiners. No statistically significant differences between CTA and DSA (p=0.097) were found for identifying branches relevant for microsurgery. DSA was superior to CTA if more peripheral ECA branches were included (P=0.030). CTA proved to be a promising alternative to DSA in vascular mapping for planning of microvascular reconstruction of the mandible.

  7. Diagnostic and Therapeutic Usefulness of Coronary Computed Tomography Angiography in Out-Clinic Patients Referred for Chest Pain.

    PubMed

    Bom, Michiel J; van der Zee, Petrus M; Cornel, Jan H; van der Zant, Friso M; Knol, Remco J J

    2015-07-01

    Coronary computed tomography angiography (CCTA) is widely used to exclude coronary artery disease (CAD) in patients with low-to-intermediate pretest probability (PTP) of obstructive CAD. The aim of our study was to investigate the reclassification by CCTA and the implications of CCTA results on management because limited studies exist on these subjects; 1,560 patients with chest pain without a history of CAD and with low or intermediate PTP of CAD referred for CCTA from the out-patient clinic were prospectively included. PTP was defined by the Duke Clinical Score as either low (<15%), low-intermediate (15% to 50%), or high-intermediate (50% to 85%). Distribution of CCTA results among the categories of PTP of CAD and the influence of CCTA results on management were analyzed. CCTA revealed obstructive CAD in 7%, 15%, and 23% of cases, in patients with low, low-intermediate, and high-intermediate PTP, respectively; 855 of 1,031 patients (83%) with intermediate PTP of CAD showed no obstructive CAD on CCTA and were consequently reclassified. Management changes after CCTA occurred in 689 patients (44%). In 633 patients (41%), medication was altered and 135 (9%) were referred for invasive coronary angiography. Treatment with statin was initiated in 442 (28%) and stopped in 71 patients (5%). Aspirin was initiated in 192 (12%) and stopped in 139 patients (9%). In conclusion, in a routine clinical cohort, CCTA resulted in reclassification in most patients. Furthermore, our study suggests that the Duke Clinical Score overestimates the probability of obstructive CAD compared with CCTA findings. Finally, CCTA results have implications on patient management, with medication changes in 41% of patients.

  8. Instantaneous wave-free ratio derived from coronary computed tomography angiography in evaluation of ischemia-causing coronary stenosis

    PubMed Central

    Ma, Yue; Liu, Hui; Hou, Yang; Qiao, Aike; Hou, Yingying; Yang, Qingqing; Guo, Qiyong

    2017-01-01

    Abstract The instantaneous wave-free ratio (iFR) closely related to fractional flow reserve (FFR) is a adenosine-independent physiologic index of coronary stenosis severity. We sought to evaluate whether iFR derived from coronary computed tomographic angiography (iFRCT) can be used as a novel noninvasive method for diagnosis of ischemia-causing coronary stenosis. We retrospectively enrolled 33 patients (47 lesions) with coronary artery disease (CAD) and examined with coronary computed tomographic angiography (CTA), invasive coronary angiography (ICA), and FFR. Patient-specific anatomical model of the coronary artery was built by original resting end-diastolic CTA images. Based on the model and computational fluid dynamics, individual boundary conditions were set to calculate iFRCT as the mean pressure distal to the stenosis divided by the mean aortic pressure during the diastolic wave-free period of rest state. Ischemia was assessed by an FFR of up to 0.8, while anatomically obstructive CAD was defined by a stenosis of at least 50% by ICA. The correlation between iFRCT and FFR was evaluated. The receiver operating characteristic (ROC) curve was used to select the cut-off value of iFRCT for diagnosis of ischemia-causing stenosis. The diagnostic performances of iFRCT, coronary CTA, and iFRCT plus CTA for ischemia-causing stenosis were compared with ROC curve and Delong method. On a per-vessel basis, iFRCT and FFR had linear correlation (r = 0.75, p < 0.01). ROC analysis identified an optimal iFRCT cut-off value of 0.82 for categorization based on an FFR cut-off value 0.8, and the diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of iFRCT were 78.72%,70.59%, 83.33%,70.59%, and 83.33%, respectively. Compared with obstructive CAD diagnosed by coronary CTA (AUC = 0.60), iFRCT yielded diagnostic improvement over stenosis assessment with AUC increasing from 0.6 by CTA to 0.87 (P < 0.01) and 0

  9. Visualization of Radial Peripapillary Capillaries Using Optical Coherence Tomography Angiography: The Effect of Image Averaging

    PubMed Central

    Phillips, Erika; Krawitz, Brian D.; Garg, Reena; Salim, Sarwat; Geyman, Lawrence S.; Efstathiadis, Eleni; Carroll, Joseph; Rosen, Richard B.; Chui, Toco Y. P.

    2017-01-01

    Objectives To assess the effect of image registration and averaging on the visualization and quantification of the radial peripapillary capillary (RPC) network on optical coherence tomography angiography (OCTA). Methods Twenty-two healthy controls were imaged with a commercial OCTA system (AngioVue, Optovue, Inc.). Ten 10x10° scans of the optic disc were obtained, and the most superficial layer (50-μm slab extending from the inner limiting membrane) was extracted for analysis. Rigid registration was achieved using ImageJ, and averaging of each 2 to 10 frames was performed in five ~2x2° regions of interest (ROI) located 1° from the optic disc margin. The ROI were automatically skeletonized. Signal-to-noise ratio (SNR), number of endpoints and mean capillary length from the skeleton, capillary density, and mean intercapillary distance (ICD) were measured for the reference and each averaged ROI. Repeated measures analysis of variance was used to assess statistical significance. Three patients with primary open angle glaucoma were also imaged to compare RPC density to controls. Results Qualitatively, vessels appeared smoother and closer to histologic descriptions with increasing number of averaged frames. Quantitatively, number of endpoints decreased by 51%, and SNR, mean capillary length, capillary density, and ICD increased by 44%, 91%, 11%, and 4.5% from single frame to 10-frame averaged, respectively. The 10-frame averaged images from the glaucomatous eyes revealed decreased density correlating to visual field defects and retinal nerve fiber layer thinning. Conclusions OCTA image registration and averaging is a viable and accessible method to enhance the visualization of RPCs, with significant improvements in image quality and RPC quantitative parameters. With this technique, we will be able to non-invasively and reliably study RPC involvement in diseases such as glaucoma. PMID:28068370

  10. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    SciTech Connect

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan

    2009-11-15

    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  11. Coronary computed tomography angiography using ultra-low-dose contrast media: radiation dose and image quality.

    PubMed

    Komatsu, Sei; Kamata, Teruaki; Imai, Atsuko; Ohara, Tomoki; Takewa, Mitsuhiko; Ohe, Ryoko; Miyaji, Kazuaki; Yoshida, Junichi; Kodama, Kazuhisa

    2013-08-01

    To analyze the invasiveness and image quality of coronary CT angiography (CCTA) with 80 kV. We enrolled 181 patients with low body weight and low calcium level. Of these, 154 patients were randomly assigned to 1 of 3 groups: 280 HU/80 kV (n = 51); 350 HU/80 kV (n = 51); or 350 HU/120 kV (n = 52). The amount of contrast media (CM) was decided with a CT number-controlling system. Twenty-seven patients were excluded because of an invalid time density curve by timing bolus. The predicted amount of CM, volume CT dose index, dose-length product, effective dose, image noise, and 5-point image quality were measured. The amounts of CM for the 80 kV/280 HU, 80 kV/350 HU, and 120 kV/350 HU groups were 10 ± 4 mL, 15 ± 7 mL, and 30 ± 6 mL, respectively. Although image noise was greater at 80 than 120 kV, there was no significant difference in image quality between 80 kV/350 HU and 120 kV/350 HU (p = 0.390). There was no significant difference in image quality between 80 kV/280 HU and 80 kV/350 HU (4.4 ± 0.7 vs. 4.7 ± 0.4, p = 0.056). The amount of CM and effective dose was lower for 80 kV CCTA than for 120 kV CCTA. CCTA at 80 kV/280 HU may decrease the amount of CM and radiation dose necessary while maintaining image quality.

  12. MR-angiography: the role of contrast agents.

    PubMed

    Goyen, M; Ruehm, S G; Debatin, J F

    2000-06-01

    Contrast-enhanced 3D MR angiography (MRA) permits comprehensive assessment of the supraaortic arteries as well as the arterial system in the chest, abdomen and lower extremities. 3D MRA combines intravenous injection of a non-nephrotoxic, paramagnetic, extracellular contrast agent that increases the signal intensity of blood by shortening its T1 value with the acquisition of a fast 3D data set. High contrast between the vascular lumen and surrounding tissues, inherent three-dimensionality and the ability to collect image data in the chest and abdomen under apnea conditions all contribute to excellent image quality. This review provides clinical applications of 3D MRA in the chest, abdomen and lower extremities based upon the available literature and several clinical examples.

  13. Magnetic resonance angiography in perforator flap breast reconstruction

    PubMed Central

    Levine, Joshua L.

    2016-01-01

    Magnetic resonance angiography (MRA) is an extremely useful preoperative imaging test for evaluation of the vasculature of donor tissue to be used in autologous breast reconstruction. MRA has sufficient spacial resolution to reliably visualize 1 mm perforating vessels and to accurately locate vessels in reference to a patient’s anatomic landmarks without exposing patients to ionizing radiation or iodinated contrast. The use of a blood pool contrast agent and the lack of radiation exposure allow multiple studies of multiple anatomic regions in one examination. The following article is a detailed description of our MRA protocol developed with our radiologists with examples that illustrate the utility of MRA in perforator flap breast reconstruction. PMID:27047787

  14. Dose reduction with adaptive bolus chasing computed tomography angiography.

    PubMed

    Cai, Zhijun; Bai, Er-Wei; Wang, Ge; Sharafuddin, Melhem J; Abada, Hicham T

    2010-01-01

    Computed Tomography (CT) has become an effective diagnosis and evaluating tool in clinical; however, its radiation exposure has drawn great attention as more and more CT scans are performed every year. How to reduce the radiation dose and meanwhile keep the resultant CT images diagnosable becomes an important research topic. In this paper, we propose a dose reduction approach along with the adaptive bolus chasing CT Angiography (CTA) techniques, which are capable of tracking the contrast bolus peak over all the blood vessel segments during the CTA scan. By modulating the tube current (and collimator width) online, we can reduce the total radiation dose and maintain the contrast to noise ratio (CNR) of the blood vessel. Numerical experiments on reference DSA data sets show that by using the proposed dose reduction method, the effective radiation dose can be saved about 39%.

  15. Dose Reduction with Adaptive Bolus Chasing Computed Tomography Angiography

    PubMed Central

    Cai, Zhijun; Bai, Er-Wei; Wang, Ge; Sharafuddin, Melhem J.; Abada, Hicham T.

    2010-01-01

    Computed Tomography (CT) has become an effective diagnosis and evaluating tool in clinical; however, its radiation exposure has drawn great attention as more and more CT scans are performed every year. How to reduce the radiation dose and meanwhile keep the resultant CT images diagnosable becomes an important research topic. In this paper, we propose a dose reduction approach along with the adaptive bolus chasing CT Angiography (CTA) techniques, which are capable of tracking the contrast bolus peak over all the blood vessel segments during the CTA scan. By modulating the tube current (and collimator width) online, we can reduce the total radiation dose and maintain the contrast to noise ratio (CNR) of the blood vessel. Numerical experiments on reference DSA data sets show that by using the proposed dose reduction method, the effective radiation dose can be saved about 39%. PMID:20421701

  16. Hepatic perfusion abnormalities during CT angiography: Detection and interpretation

    SciTech Connect

    Freeny, P.C.; Marks, W.M.

    1986-06-01

    Twenty-seven perfusion abnormalities were detected in 17 of 50 patients who underwent computed tomographic angiography (CTA) of the liver. All but one of the perfusion abnormalities occurred in patients with primary or metastatic liver tumors. Perfusion abnormalities were lobar in nine cases, segmental in 11, and subsegmental in seven; 14 were hypoperfusion and 13 were hyperperfusion abnormalities. The causes for the abnormalities included nonperfusion of a replaced hepatic artery (n = 11), cirrhosis and nodular regeneration (n = 3), altered hepatic hemodynamics (e.g., siphoning, laminar flow) caused by tumor (n = 7), contrast media washout from a nonperfused vessel (n = 1), compression of adjacent hepatic parenchyma (n = 1), and unknown (n = 4). Differentiation of perfusion abnormalities from tumor usually can be made by comparing the morphology of the known tumor with the suspected perfusion abnormality, changes of each on delayed CTA scans, and review of initial angiograms and other imaging studies.

  17. Transvenous coronary angiography in humans with synchrotron radiation

    SciTech Connect

    Thomlinson, W.

    1994-10-01

    The transvenous coronary angiography project at the National Synchrotron Light Source (NSLS) is presently undergoing a significant upgrade to the hardware and software in the synchrotron medical facility. When completed, the project will have reached a level of maturity in the imaging technology which will allow the research team to begin to concentrate on medical research programs. This paper will review the status of the project and imaging technology and will discuss the current upgrades and future advanced technology initiatives. The advantages of using the radiation from a synchrotron, over that from a standard x-ray source, were the motivation for the project. A total of 23 human imaging sessions have been carried out with in the project. The primary goals have been to establish the imaging parameters and protocol necessary to obtain clinically useful images.

  18. Statistical analysis of motion contrast in optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Cheng, Yuxuan; Guo, Li; Pan, Cong; Lu, Tongtong; Hong, Tianyu; Ding, Zhihua; Li, Peng

    2015-11-01

    Optical coherence tomography angiography (Angio-OCT), mainly based on the temporal dynamics of OCT scattering signals, has found a range of potential applications in clinical and scientific research. Based on the model of random phasor sums, temporal statistics of the complex-valued OCT signals are mathematically described. Statistical distributions of the amplitude differential and complex differential Angio-OCT signals are derived. The theories are validated through the flow phantom and live animal experiments. Using the model developed, the origin of the motion contrast in Angio-OCT is mathematically explained, and the implications in the improvement of motion contrast are further discussed, including threshold determination and its residual classification error, averaging method, and scanning protocol. The proposed mathematical model of Angio-OCT signals can aid in the optimal design of the system and associated algorithms.

  19. Hematocrit dependence of flow signal in optical coherence tomography angiography

    PubMed Central

    Yang, Jianlong; Su, Johnny; Wang, Jie; Men, Silu; Jia, Yali; Huang, David; Liu, Gangjun

    2017-01-01

    The hematocrit dependence of flow signal (split-spectrum amplitude decorrelation angiography-SSADA decorrelation value) was investigated in this paper. Based on the normalized field temporal correlation function and concentration dependent particle scattering properties, the relationship between hematocrit and flow signal was analytically derived. Experimental verification of the relationship was performed with custom-designed microfluidic chips and human blood with 45%, 40% and 32% hematocrit. It was found that, in large flow channels and blood vessels, the normal hematocrit is near the decorrelation saturation point and therefore a change in hematocrit has little effect on the SSADA decorrelation value (flow signal). However, in narrow channels in the capillary size range, the effective hematocrit (adjusted for the overlap between OCT beam and channel) is in the range of 6.7-9.5% and therefore variation in hematocrit does significantly affect the flow signal. PMID:28270984

  20. Gadolinium-enhanced magnetic resonance angiography in brain death

    NASA Astrophysics Data System (ADS)

    Luchtmann, M.; Beuing, O.; Skalej, M.; Kohl, J.; Serowy, S.; Bernarding, J.; Firsching, R.

    2014-01-01

    Confirmatory tests for the diagnosis of brain death in addition to clinical findings may shorten observation time required in some countries and may add certainty to the diagnosis under specific circumstances. The practicability of Gadolinium-enhanced magnetic resonance angiography to confirm cerebral circulatory arrest was assessed after the diagnosis of brain death in 15 patients using a 1.5 Tesla MRI scanner. In all 15 patients extracranial blood flow distal to the external carotid arteries was undisturbed. In 14 patients no contrast medium was noted within intracerebral vessels above the proximal level of the intracerebral arteries. In one patient more distal segments of the anterior and middle cerebral arteries (A3 and M3) were filled with contrast medium. Gadolinium-enhanced MRA may be considered conclusive evidence of cerebral circulatory arrest, when major intracranial vessels fail to fill with contrast medium while extracranial vessels show normal blood flow.

  1. Three-dimensional computed tomography angiography for the investigation of superficial temporal artery pseudoaneurysms--two case reports--.

    PubMed

    Higashino, Takuya; Kawashima, Masatou; Mannoji, Hiromichi

    2005-03-01

    An 89-year-old man and a 60-year-old man presented with superficial temporal artery (STA) pseudoaneurysms which developed secondary to trauma. Conventional cerebral angiography and three-dimensional computed tomography (3D CT) angiography clearly demonstrated the STA pseudoaneurysms. The patients underwent surgical excision of the aneurysms based on the conventional cerebral angiography findings in one patient and 3D CT angiography findings in other patient. 3D CT angiography is an excellent noninvasive diagnostic method for detecting extracranial aneurysms such as STA pseudoaneurysm, especially the relationship between the aneurysm and surrounding structures, including the calvarium.

  2. Sac Angiography and Glue Embolization in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysm

    SciTech Connect

    Koike, Yuya Nishimura, Jun-ichi Hase, Soichiro Yamasaki, Motoshige

    2015-04-15

    PurposeThe purpose of this study was to demonstrate a sac angiography technique and evaluate the feasibility of N-butyl cyanoacrylate (NBCA) embolization of the ruptured abdominal aortic aneurysm (AAA) sac in emergency endovascular aneurysm repair (EVAR) in hemodynamically unstable patients.MethodsA retrospective case series of three patients in whom sac angiography was performed during emergency EVAR for ruptured AAA was reviewed. After stent graft deployment, angiography within the sac of aneurysm (sac angiography) was performed by manually injecting 10 ml of contrast material through a catheter to identify the presence and site of active bleeding. In two patients, sac angiography revealed active extravasation of the contrast material, and NBCA embolization with a coaxial catheter system was performed to achieve prompt sealing.ResultsSac angiography was successful in all three patients. In the two patients who underwent NBCA embolization for aneurysm sac bleeding, follow-up computed tomography (CT) images demonstrated the accumulation of NBCA consistent with the bleeding site in preprocedural CT images.ConclusionsEVAR is associated with a potential risk of ongoing bleeding from type II or IV endoleaks into the disrupted aneurysm sac in patients with severe coagulopathy. Therefore, sac angiography and NBCA embolization during emergency EVAR may represent a possible technical improvement in the treatment of ruptured AAA in hemodynamically unstable patients.

  3. Iodixanol, a new isosmotic nonionic contrast agent compared with iohexol in cardiac angiography.

    PubMed

    Hill, J A; Cohen, M B; Kou, W H; Mancini, G B; Mansour, M; Fountaine, H; Brinker, J A

    1994-07-01

    Iodixanol, a new ratio 6 nonionic iodinated contrast agent with an osmolality equal to serum, was compared with iohexol in a randomized, double-blind, parallel study. Two hundred patients undergoing elective diagnostic cardiac angiography were randomized to iodixanol (n = 101) or iohexol (n = 99). There were no differences noted between the 2 agents in the mean changes in systolic or diastolic blood pressure or heart rate during or immediately after any angiography. However, significantly more patients had a decrease in diastolic blood pressure of > 20 mm Hg during left coronary angiography with iodixanol. The only significant differences in any electrophysiologic parameter were slightly more PR prolongation during left coronary angiography with iodixanol and more ST-segment depression with iohexol during coronary angiography. Neither was clinically significant. Injection-associated discomfort occurred with both agents, but more patients experienced moderate to severe discomfort with iohexol (52%) than with iodixanol (17%) (p < 0.001). Only 1 potentially serious adverse event, ventricular fibrillation with iohexol, was considered related to contrast, and there were no differences noted between the agents. Overall, angiographic quality was equal with all angiograms being assessed as good or excellent in both groups (p = 0.885). In this low-risk population undergoing cardiac angiography, iodixanol is safe and effective without clinically important differences from iohexol. Additional studies in patients at high risk for complications should help further define the role of iodixanol in cardiac angiography.

  4. Non-clinical factors influencing the selection of patients with acute coronary syndromes for angiography

    PubMed Central

    Quaas, A; Curzen, N; Garratt, C

    2004-01-01

    Objective: To analyse clinical and non-clinical factors determining the selection for coronary angiography in patients with acute coronary syndromes (ACS). Design: Single centre, prospective cohort study. Participants: Eighty consecutive patients admitted with a diagnosis of ACS during the period 21 May 2001 to 4 July 2001. Setting: Coronary care unit of a tertiary referral centre, the Manchester Royal Infirmary. Data collection: Information concerning baseline patient characteristics, clinical presentation, and the selection for angiography was collected from the patient notes. Data analysis: Windows SPSS version 9.0 using cross tabulations with χ2 estimation and binomial logistic regression analysis. Main outcome measure: Selection for angiography in ACS. Results: Cross tabulations with χ2 analysis and logistic regression analysis identified significant non-clinical factors predicting the use of angiography. Although clinical factors such as recurrent ischaemia (odds ratio 5.11) influenced the decision to undergo coronary angiography, non-clinical factors such as young age (odds ratio 6.88 for <65 years old), gender (odds ratio 3.81 for males), admission on a weekday (odds ratio 0.2488 for admission on the weekend), and consultant in charge (odds ratio 0.111 for consultant "2") independently predicted the use of angiography in ACS. Conclusion: The selection of patients for angiography in ACS is not based purely on clinical criteria. Awareness of the apparent sources of bias among clinical decision makers may improve management of these patients. PMID:15254306

  5. Atherosclerosis and Liver Function Tests in Coronary Angiography Patients

    PubMed Central

    Doganer, YC; Rohrer, JE; Aydogan, U; Agerter, DC; Cayci, T; Barcin, C

    2015-01-01

    ABSTRACT Objective: Elevated aminotransferase levels indicating liver function, even in the normal range, have attracted great concern as potential novel markers of cardiovascular risk assessment. We hypothesized the possibility that liver function test variations in the normal range might be meaningfully associated to coronary artery disease (CAD). Method: Eighty-eight patients were randomly selected from those who underwent coronary angiography from June 2010 to June 2011 after applying to the outpatient cardiology clinic in Gulhane Military Medical Academy. According to the results of angiographies, patients were classified into three groups as normal, non-critical (< 50% involvement in coronaries), and critical (≥ 50% involvement in coronaries). In addition to angiographic intervention, measurements of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations, albumin and the other serum parameters were performed in all patients. Results: The patient groups of CAD were balanced (28 critical cases, 30 non-critical cases and 30 normal cases). Mean age was 51.93 ± 9.3 (range 32–65) years and 19.3 per cent (n = 17) were females. Multiple linear regression analysis of all three liver function tests explained a significant portion of the variance, but adjusted r-squares were small (AST = 0.174, ALT = 0.242, albumin = 0.124). Albumin was significantly higher for patients with critical CAD than for patients with no CAD (beta = 3.205, p = 0.002). Non-critical CAD was not significantly different from no CAD for any of the dependent variables. Mean AST was significantly higher for patients taking aspirin (beta = 0.218, p = 0.049), as was mean ALT (beta = 0.264, p = 0.015). Conclusion: Alanine aminotransferase and AST may not be associated with angiographically determined coronary atherosclerosis. Albumin may be more sensitive to demonstrate the burden of atherosclerosis. These results indicate that the association between the liver

  6. The Hunter pulmonary angiography catheter for a brachiocephalic vein approach.

    PubMed

    Rosen, Galia; Kowalik, Karen J; Ganguli, Suverano; Hunter, David W

    2006-01-01

    The purpose of this work was to describe our experience in performing pulmonary angiography using the Hunter pulmonary catheter, manufactured by Cook, Inc., which is a modified 6F pigtail catheter with a "C-shaped" curve, designed for a brachiocephalic vein approach. One hundred twenty-three patients underwent pulmonary angiograms using the Hunter catheter between August 1997 and January 2002. Operator comments were gathered in 86 (70%) of the cases. The operator was, if possible, the most junior resident on the service. Thirty-nine operators participated in the survey. Efficacy, safety, and ease of use of the catheter were determined by operators' comments and ECG observations during the procedure. Corroborating clinical data were gathered from medical records. In 68 (79%) of the procedures that were commented upon, the operator described insertion into the pulmonary artery (PA) as easy; only 2 (2%) indicated difficulty in accessing the PA. In 41 (63%) of the bilateral angiograms that were commented upon, the operator described accessing the left PA from the right PA as easy; only 6 (9%) rated it as difficult and all were with an older technique in which the catheter was withdrawn to the pulmonary bifurcation without a wire or with only the soft tip of the wire in the pigtail and then rotated to the left main pulmonary artery. Thirty-one of the 41 patients who demonstrated premature ventricular contractions (PVCs) had a previous history of heart disease. Nineteen of the 39 patients who did not have PVCs had a history of heart disease (p = 0.018). The maneuverability and shape of the Hunter catheter make pulmonary angiography an easy procedure, even for operators with minimal experience and limited technical proficiency. PVCs demonstrated a statistically significant correlation with a positive patient history for cardiac disease, rather than being a universal risk.

  7. Automated myocardial perfusion from coronary x-ray angiography

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2010-03-01

    The purpose of our study is the evaluation of an algorithm to determine the physiological relevance of a coronary lesion as seen in a coronary angiogram. The aim is to extract as much as possible information from a standard coronary angiogram to decide if an abnormality, percentage of stenosis, as seen in the angiogram, results in physiological impairment of the blood supply of the region nourished by the coronary artery. Coronary angiography, still the golden standard, is used to determine the cause of angina pectoris based on the demonstration of an important stenose in a coronary artery. Dimensions of a lesion such as length and percentage of narrowing can at present easily be calculated by using an automatic computer algorithm such as Quantitative Coronary Angiography (QCA) techniques resulting in just anatomical information ignoring the physiological relevance of the lesion. In our study we analyze myocardial perfusion images in standard coronary angiograms in rest and in artificial hyperemic phases, using a drug e.g. papaverine intracoronary. Setting a Region of Interest (ROI) in the angiogram without overlying major vessels makes it possible to calculate contrast differences as a function of time, so called time-density curves, in the basal and hyperemic phases. In minimizing motion artifacts, end diastolic images are selected ECG based in basal and hyperemic phase in an identical ROI in the same angiographic projection. The development of new algorithms for calculating differences in blood supply in the region as set are presented together with the results of a small clinical case study using the standard angiographic procedure.

  8. Swept Source OCT Angiography of Neovascular Macular Telangiectasia Type 2

    PubMed Central

    Zhang, Qinqin; Wang, Ruikang K.; Chen, Chieh-Li; Legarreta, Andrew D.; Durbin, Mary K.; An, Lin; Sharma, Utkarsh; Stetson, Paul F.; Legarreta, John E.; Roisman, Luiz; Gregori, Giovanni; Rosenfeld, Philip J.

    2015-01-01

    Objective To image subretinal neovascularization in proliferative macular telangiectasia type 2 (MacTel2) using swept source optical coherence tomography based microangiography (OMAG). Study Design Patients with MacTel2 were enrolled in a prospective, observational study known as the MacTel Project and evaluated using a high-speed 1050nm swept-source OCT (SS-OCT) prototype system. The OMAG algorithm generated en face flow images from three retinal layers, as well as the region bounded by the outer retina and Bruch’s membrane, the choriocapillaris, and the remaining choroidal vasculature. The en face OMAG images were compared to images from fluorescein angiography (FA) and indocyanine green angiography (ICGA). Results Three eyes with neovascular MacTel2 were imaged. The neovascularization was best identified from the en face OMAG images that included a layer between the outer retinal boundary and Bruch’s membrane. OMAG images identified these abnormal vessels better than FA and were comparable to the images obtained using ICGA. In all three cases, OMAG identified choroidal vessels communicating with the neovascularization, and these choroidal vessels were evident in the two cases with ICGA imaging. In one case, monthly injections of bevacizumab reduced the microvascular complexity of the neovascularization, as well as the telangiectatic changes within the retinal microvasculature. In another case, less frequent bevacizumab therapy was associated with growth of the subretinal neovascular complex. Conclusions OMAG imaging provided detailed, depth-resolved information about subretinal neovascularization in MacTel2 eyes demonstrating superiority to FA imaging and similarities to ICGA imaging for documenting the retinal microvascular changes, the size and extent of the neovascular complex, the communications between the neovascular complex and the choroidal circulation, and the response to monthly bevacizumab therapy. PMID:26457402

  9. The Hunter Pulmonary Angiography Catheter for a Brachiocephalic Vein Approach

    SciTech Connect

    Rosen, Galia Kowalik, Karen J.; Ganguli, Suverano; Hunter, David W.

    2006-12-15

    The purpose of this work was to describe our experience in performing pulmonary angiography using the Hunter pulmonary catheter, manufactured by Cook, Inc., which is a modified 6F pigtail catheter with a 'C-shaped' curve, designed for a brachiocephalic vein approach. One hundred twenty-three patients underwent pulmonary angiograms using the Hunter catheter between August 1997 and January 2002. Operator comments were gathered in 86 (70%) of the cases. The operator was, if possible, the most junior resident on the service. Thirty-nine operators participated in the survey. Efficacy, safety, and ease of use of the catheter were determined by operators' comments and ECG observations during the procedure. Corroborating clinical data were gathered from medical records. In 68 (79%) of the procedures that were commented upon, the operator described insertion into the pulmonary artery (PA) as easy; only 2 (2%) indicated difficulty in accessing the PA. In 41 (63%) of the bilateral angiograms that were commented upon, the operator described accessing the left PA from the right PA as easy; only 6 (9%) rated it as difficult and all were with an older technique in which the catheter was withdrawn to the pulmonary bifurcation without a wire or with only the soft tip of the wire in the pigtail and then rotated to the left main pulmonary artery. Thirty-one of the 41 patients who demonstrated premature ventricular contractions (PVCs) had a previous history of heart disease. Nineteen of the 39 patients who did not have PVCs had a history of heart disease (p = 0.018). The maneuverability and shape of the Hunter catheter make pulmonary angiography an easy procedure, even for operators with minimal experience and limited technical proficiency. PVCs demonstrated a statistically significant correlation with a positive patient history for cardiac disease, rather than being a universal risk.

  10. Decreased Diagnostic Accuracy of Multislice Coronary Computed Tomographic Angiography in Women with Atypical Angina Symptoms

    PubMed Central

    Jin, Wen-Ying; Zhao, Xiu-Juan; Chen, Hong

    2016-01-01

    Background: Multislice computed tomography (MSCT) coronary angiography (CAG) is a noninvasive technique with a reported high diagnostic accuracy for coronary artery disease (CAD). Women, more frequently than men, are known to develop atypical angina symptoms. The purpose of this study was to investigate whether the diagnostic accuracy of MSCT in women with atypical presentation differs from that in men. Methods: We enrolled 396 in-hospital patients (141 women and 255 men) with suspected or proven CAD who successively underwent both MSCT and invasive CAG. CAD was defined as any coronary stenosis of ≥50% on conventional invasive CAG, which was used as the reference standard. The patients were divided into typical and atypical groups based on their symptoms of angina pectoris. The diagnostic accuracy of MSCT, including its sensitivity, specificity, negative predictive value, and positive predictive value (PPV), was calculated to determine the usefulness of MSCT in assessing stenoses. The diagnostic performance of MSCT was also assessed by constructing receiver operating characteristic (ROC) curves. Results: The PPV (91% vs. 97%, χ2 = 5.705, P < 0.05) and diagnostic accuracy (87% vs. 93%, χ2 = 5.093, P < 0.05) of MSCT in detecting CAD were lower in women than in men. Atypical presentation was an independent influencing factor on the diagnostic accuracy of MSCT in women (odds ratio = 4.94, 95% confidence intervals: 1.16–20.92, Walds = 4.69, P < 0.05). Compared with those in the atypical group, women with typical angina pectoris had higher PPV (98% vs. 74%, χ2 = 17.283. P < 0.001), diagnostic accuracy (93% vs. 72%, χ2 = 9.571, P < 0.001), and area under the ROC curve (0.91 vs. 0.64, Z = 2.690, P < 0.01) in MSCT diagnosis. Conclusions: Although MSCT is a reliable diagnostic modality for the exclusion of significant coronary artery stenoses in all patients, gender and atypical symptoms might have some influence on its diagnostic accuracy. PMID:27625091

  11. [Transient cortical blindness--a complication after coronary angiography--case report].

    PubMed

    Borowik, Helena; Kułakowska, Alina; Drozdowski, Wiesław; Dubicki, Artur; Kraśnicki, Paweł

    2008-05-01

    Transient cortical blindness is a very rare complication of cardiovascular and cerebral angiography procedures. We present a case of 63-years-old woman, who developed cortical blindness after coronary angiography. Computed tomography (CT) done immediately after blindness appearance showed bilateral hyperintensive areas (probably due to a leakage of contrast medium) in the occipital and parietal cerebral lobes. All visual symptoms disappeared during 48 hours and CT scan repeated after sight recovery did not show any focal lesions in the brain. A breakdown of the blood-brain barrier with direct contrast neurotoxicity seems to be the causal factor of neurological changes observed in our patient after coronary angiography.

  12. Acoustic angiography: a new high frequency contrast ultrasound technique for biomedical imaging

    NASA Astrophysics Data System (ADS)

    Shelton, Sarah E.; Lindsey, Brooks D.; Gessner, Ryan; Lee, Yueh; Aylward, Stephen; Lee, Hyunggyun; Cherin, Emmanuel; Foster, F. Stuart; Dayton, Paul A.

    2016-05-01

    Acoustic Angiography is a new approach to high-resolution contrast enhanced ultrasound imaging enabled by ultra-broadband transducer designs. The high frequency imaging technique provides signal separation from tissue which does not produce significant harmonics in the same frequency range, as well as high resolution. This approach enables imaging of microvasculature in-vivo with high resolution and signal to noise, producing images that resemble x-ray angiography. Data shows that acoustic angiography can provide important information about the presence of disease based on vascular patterns, and may enable a new paradigm in medical imaging.

  13. Pulmonary Angiography and Embolization for Severe Hemoptysis Due to Cavitary Pulmonary Tuberculosis

    SciTech Connect

    Sanyika, Charles; Corr, Peter; Royston, Duncan; Blyth, David F.

    1999-11-15

    Purpose: To identify the role of pulmonary angiography in the diagnosis and treatment of severe hemoptysis due to cavitary pulmonary tuberculosis. Methods: Selective pulmonary angiography was performed on eight patients with severe hemoptysis uncontrolled by previous bronchial and systemic arterial embolization. Results: Three (38%) patients had Rasmussen aneurysms, which were successfully embolized with steel coils. Five patients demonstrated pulmonary arterial hypoperfusion in the diseased lung. Conclusions: We recommend pulmonary angiography in cavitary tuberculous patients with severe hemoptysis who do not respond to systemic arterial embolization. Rasmussen aneurysms are effectively treated by steel coil occlusion.

  14. Whole body magnetic resonance angiography and computed tomography angiography in the vascular mapping of head and neck: an intraindividual comparison

    PubMed Central

    2014-01-01

    Introduction The aim of the study was to compare the detectability of neck vessels with contrast enhanced magnetic resonance angiography (MRA) in the setting of a whole-body MRA and multislice computed tomography angiography (CTA) for preoperative vascular mapping of head and neck. Methods In 20 patients MRA was performed prior to microvascular reconstruction of the mandible with osteomyocutaneous flaps. CTA of the neck served as the method of reference. 1.5 T contrast enhanced magnetic resonance angiograms were acquired to visualize the vascular structures of the neck in the setting of a whole-body MRA examination. 64-slice spiral computed tomography was performed with a dual-phase protocol, using the arterial phase images for 3D CTA reconstruction. Maximum intensity projection was employed to visualize MRA and CTA data. To retrieve differences in the detectability of vessel branches between MRA and CTA, a McNemar test was performed. Results All angiograms were of diagnostic quality. There were no statistically significant differences between MRA and CTA for the detection of branches of the external carotid artery that are relevant host vessels for microsurgery (p = 0.118). CTA was superior to MRA if all the external carotid artery branches were included (p < 0.001). Conclusions MRA is a reliable alternative to CTA in vascular mapping of the cervical vasculature for planning of microvascular reconstruction of the mandible. In the setting of whole-body MRA it could serve as a radiation free one-stop-shop tool for preoperative assessment of the arterial system, potentially covering both, the donor and host site in one single examination. PMID:24884580

  15. Early Experience Studying Cerebral Aneurysms with Rotational and Three-dimensional Angiography and Review of CT and MR Angiography Literature

    PubMed Central

    Castaño-Duque, C.H.; Ruscalleda-Nadal, J.; De Juan-Delago, M.; Guardia-Mas, E.; San Roman-Manzanera, L.; Bartomeus-Jene, F.; Molet-Teixido, J.; Tresserras-Ribo, P.; Pares-Muñoz, P.; Clavel Laria, P.

    2002-01-01

    Summary From september 2000 to september 2001, 32 consecutive patients with ruptured intracranial aneurysms were examined with rotational and 3D reconstruction angiography using an Integris V5000 Philips Medical System: 39 aneurysms were detected. After a selective cerebral artery was catheterized with a 5F or 4F-catheter, 35 ml of contrast medium was intra-arterially administered at a rate of 4 ml/s and a 180° rotational angiography was performed in eight seconds. This information was transferred to a computer (Silicon Graphics Octane) with software (Integris 3D-RA, Philips Integris Systems) and a three-dimensional reconstruction was made. The information provided by Angio-3D was useful for evaluating the parent artery, aneurysmal sac, aneurysmal neck and arterial branches. It was also very useful in selecting the therapeutic method. For open surgery, this technique provides preoperative images that are useful for planning microsurgical approaches, especially in cases of large aneurysm showing complex surrounding arteries. For endovascular embolization, various anatomic characteristics of the aneurysm such as neck and sac size, shape, lobularity, parent artery and arterial branches adjacent to the aneurysmal neck must be demonstrated. This is very important to determine the best projection for embolization and to avoid multiple series. This is also essential in the choice of the first coil to create a good basket producing total occlusion. Microaneurysms are demonstrated well with this technique whereas this is difficult to do with conventional arteriography. The Angio-RM and Angio-CT literature show a lower sensitivity and specificity in comparasion with our experience with 3D IA-ROT-DSA. For this reason, we believe that 3D IA-ROT-DSA is now the gold standard for patients presenting intracranial aneurysms. PMID:20594499

  16. Prostate resection - minimally invasive

    MedlinePlus

    ... invasive - discharge Transurethral resection of the prostate - discharge Review Date 6/29/2015 Updated by: Jennifer Sobol, ... the Michigan Institute of Urology, West Bloomfield, MI. Review provided by VeriMed Healthcare Network. Also reviewed by ...

  17. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    PubMed Central

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-01-01

    Introduction Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Methods Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (PKA), skin surface entrance dose (KAR), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the PKA. Results 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median KAR = 581 mGy (374–876). Median PKA = 3908 uGym2 (2489–5865) DRL = 5865 uGym2. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median KAR = 1501 mGy (928–2224). Median PKA = 8736 uGym2 (5449–12,900) DRL = 12,900 uGym2. Conclusion This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities. PMID:26229649

  18. The Incremental Diagnostic Performance of Coronary Computed Tomography Angiography Added to Myocardial Perfusion Imaging in Patients with Intermediate-to-High Cardiovascular Risk

    PubMed Central

    Hsu, Pei-Ying; Lee, Wen-Jeng; Cheng, Mei-Fang; Yen, Ruoh-Fang; Tzen, Kai-Yuan; Wu, Yen-Wen

    2016-01-01

    Purpose Several studies have suggested that a combined approach of stress myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) can provide diagnostic results with excellent accuracy. We aimed to explore whether the addition of CCTA to stress MPI provides incremental diagnostic value in intermediate-to-high cardiovascular risk patients. Methods A total of 106 consecutive patients (93 male, 65 ± 10.4 years) underwent coronary artery calcium scoring (CACS), CCTA and 201Thallium stress MPI before coronary angiography was reviewed. Thirty-seven patients (34.9%) had a history of proven coronary artery disease (CAD) or revascularization procedures, and four had documented non-significant CAD (3.8%). The remaining patients consisted of 17 (16.0%) classified as intermediate, and 48 (45.3%) as the high-risk groups. Results Obstructive CAD was diagnosed by invasive coronary angiography in 88 patients with 161 vessels. The sensitivity and specificity in a patient-based analysis for obstructive CAD were 99% and 17% for CCTA, 80% and 50% for MPI and 91% and 67% for the combined method, respectively. The per-vessel diagnostic sensitivity and specificity were 95% and 54% for CCTA, 59% and 75% for MPI and 84% and 76% for the combined method. There were significant differences (p < 0.05) when comparing the combined method with MPI or CCTA by areas under the curve in a patient- or vessel-based analysis. However, CACS of 400 or more could not further stratify the patients with obstructive CAD. Conclusions CCTA, not CACS, provided additional diagnostic values to stress MPI in patients with intermediate-to-high cardiovascular risk. PMID:27122945

  19. Minimally invasive stomas.

    PubMed

    Hellinger, Michael D; Al Haddad, Abdullah

    2008-02-01

    Traditionally, stoma creation and end stoma reversal have been performed via a laparotomy incision. However, in many situations, stoma construction may be safely performed in a minimally invasive nature. This may include a trephine, laparoscopic, or combined approach. Furthermore, Hartmann's colostomy reversal, a procedure traditionally associated with substantial morbidity, may also be performed laparoscopically. The authors briefly review patient selection, preparation, and indications, and focus primarily on surgical techniques and results of minimally invasive stoma creation and Hartmann's reversal.

  20. Minimally invasive lumbar foraminotomy.

    PubMed

    Deutsch, Harel

    2013-07-01

    Lumbar radiculopathy is a common problem. Nerve root compression can occur at different places along a nerve root's course including in the foramina. Minimal invasive approaches allow easier exposure of the lateral foramina and decompression of the nerve root in the foramina. This video demonstrates a minimally invasive approach to decompress the lumbar nerve root in the foramina with a lateral to medial decompression. The video can be found here: http://youtu.be/jqa61HSpzIA.

  1. Parasites and marine invasions

    USGS Publications Warehouse

    Torchin, M.E.; Lafferty, K.D.; Kuris, A.M.

    2002-01-01

    Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer parasites in their introduced range compared to their native range. Parasites are ubiquitous and pervasive in marine systems, yet their role in marine invasions is relatively unexplored. Although data on parasites of marine organisms exist, the extent to which parasites can mediate marine invasions, or the extent to which invasive parasites and pathogens are responsible for infecting or potentially decimating native marine species have not been examined. In this review, we present a theoretical framework to model invasion success and examine the evidence for a relationship between parasite presence and the success of introduced marine species. For this, we compare the prevalence and species richness of parasites in several introduced populations of marine species with populations where they are native. We also discuss the potential impacts of introduced marine parasites on native ecosystems.

  2. Transient cortical blindness following vertebral angiography in a young adult with cerebellar haemangioblastoma.

    PubMed

    Till, Viktor; Koprivsek, Katarina; Stojanovic, Sanja; Avramov, Predrag; Vulekovic, Petar

    2009-11-01

    Transient cortical blindness is reported to occur in 0.3% to 1% of cerebral angiography procedures. It develops within minutes of contrast medium injection and lasts for up to several days. We report a long episode of transient cortical blindness in a 17-year-old boy with cerebellar haemangioblastoma, which started during the preoperative vertebral angiography and lasted for 5 days. CT performed 2 days after the sudden onset of bilateral visual loss showed multiple asymmetrical lesions within the brain parenchyma in the distribution of the posterior cerebral circulation. Even though the patient's vision was completely restored 5 days after angiography, repeat MRI performed 2 months after angiography showed improvement but with residual lesions in the thalami, cerebellum and occipital lobe.

  3. Reversible Cerebral Vasoconstriction Syndrome Promptly Diagnosed with Magnetic Resonance Imaging Including Magnetic Resonance Angiography During Immunosuppressive Therapy in a 16-Year-Old Girl with Refractory Cytopenia of Childhood

    PubMed Central

    Ueki, Hideaki; Sanayama, Yasushi; Miyajima, Akiyo; Tsuchimochi, Taichiro; Igarashi, Shunji; Sunami, Shosuke

    2016-01-01

    Reversible cerebral vasoconstriction syndrome (RCVS) is a syndrome characterized by severe headache with segmental vasoconstriction of the cerebral arteries that resolves within 12 weeks. A 16-year-old girl with refractory cytopenia of childhood, who was receiving the immunosuppressant cyclosporine, developed severe headache and was diagnosed with RCVS using magnetic resonance imaging, including magnetic resonance angiography (MRA). MRA is a non-invasive and very effective technique for diagnosing RCVS. MRA should be performed at the onset of severe headache during immunosuppressant administration for children with hematological disorders and may prevent sequelae such as posterior reversible encephalopathy syndrome or ischemic attack. PMID:27994838

  4. Balloon-Assisted Tracking to Overcome Radial Spasm during Transradial Coronary Angiography: A Case Report

    PubMed Central

    Verouden, N. J. W.; Kiemeneij, F.

    2014-01-01

    Spasm of the radial artery is the most important cause of failure to perform coronary angiography via the transradial approach. Spasmolytic cocktail may prevent radial artery spasm but is relatively contraindicated in patients with aortic stenosis or diminished left ventricular function. In this case report we describe a recently published technique to overcome severe radial spasm during transradial coronary angiography in a patient with moderate aortic valve stenosis. PMID:24826306

  5. Balloon-Assisted Tracking to Overcome Radial Spasm during Transradial Coronary Angiography: A Case Report.

    PubMed

    Verouden, N J W; Kiemeneij, F

    2014-01-01

    Spasm of the radial artery is the most important cause of failure to perform coronary angiography via the transradial approach. Spasmolytic cocktail may prevent radial artery spasm but is relatively contraindicated in patients with aortic stenosis or diminished left ventricular function. In this case report we describe a recently published technique to overcome severe radial spasm during transradial coronary angiography in a patient with moderate aortic valve stenosis.

  6. Optical Coherence Tomography Angiography Demonstration of Choroidal Neovascularization in Malattia Leventinese.

    PubMed

    Corbelli, Eleonora; Corvi, Federico; Carnevali, Adriano; Querques, Lea; Zucchiatti, Ilaria; Bandello, Francesco; Querques, Giuseppe

    2016-06-01

    In a case of Malattia Leventinese, optical coherence tomography angiography led to the diagnosis of type 1 neovascularization, despite absence of evidence on conventional dye-based angiography. The authors hypothesize that, at least in some cases, accumulation of subretinal fluid in Malattia Leventinese could be due to a subretinal pigment epithelium (RPE) neovascular component rather than creation of hydrophobic barrier at the RPE and Bruch's membrane. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:602-604.].

  7. Anterior Diabetic Retinopathy Studied by Ultra-widefield Angiography

    PubMed Central

    Bae, Kunho; Lee, Ju Yeon; Kim, Tae Hyup; Cho, Ga Eun; Ahn, Jeeyun; Kim, Sang Jin; Kim, Jae Hyun

    2016-01-01

    Purpose To evaluate the prevalence of anterior type diabetic retinopathy (DR) using ultra-widefield fluorescein angiography and to identify the factors associated with anterior type DR incidence. Methods A retrospective case review was used in this study. Patients with non-proliferative diabetic retinopathy (NPDR) underwent examination by ultra-widefield fluorescein angiography, and were classified into anterior, posterior, or diffuse DR groups. Anterior DR was defined if diabetic retinal changes were noted only at the location anterior to the imaginary circle bordered by the Early Treatment Diabetic Retinopathy Study seven-standard fields. Correlations between demographic data, as well as systemic and ocular factors, and the incidence of NPDR types were evaluated. Results Among the 234 eyes of 234 patients with NPDR, 25 eyes (10.7%) demonstrated anterior DR. Anterior DR was observed in 10 eyes (30.3%) of patients having mild NPDR, three eyes (4.8%) of moderate NPDR patients, and in 12 eyes (7.1%) of severe NPDR patients (p < 0.001). The incidence of anterior DR positively correlated with lower hemoglobin A1c levels and with greater high-density lipoprotein levels following multiple logistic regression analysis (p < 0.001). The mean hemoglobin A1c level was 7.03 ± 0.99% in anterior DR, 7.99 ± 1.74% in posterior DR, and 7.94 ± 1.39% in diffuse DR patients (p = 0.003). The mean high-density lipoprotein level was 51.2 ± 12.5 mg/dL in anterior, 49.7 ± 15.2 mg/dL in posterior, and 45.2 ± 13.1 mg/dL in diffuse DR patients (p = 0.010). Conclusions Diabetic retinal changes confined to an anterior location were more frequently noted in earlier stages of NPDR. The incidence of DR sparing posterior retinal involvement was related to favorable blood sugar and lipid profiles. PMID:27729754

  8. Comparison of Non-Invasive Methods for the Detection of Coronary Atherosclerosis

    PubMed Central

    Bampi, Angela Bacelar Albuquerque; Rochitte, Carlos Eduardo; Favarato, Desiderio; Lemos, Pedro Alves; da Luz, Protásio Lemos

    2009-01-01

    BACKGROUND: Non-invasive detection of atherosclerosis is critical for its prevention. Objective: To correlate non-invasively detectable indicators of coronary atherosclerosis, or Coronary Artery Disease (i.e., classical risk factors, hs-CRP test results, carotid intima-media thickness, endothelial function, ankle-brachial index and calcium score by computed tomography) with the extent of coronary disease assessed by the Friesinger index from conventional coronary angiography. METHODS: We conducted a prospective study of 100 consecutive patients, mean age 55.1 ± 10.7 years, 55% men and 45% women. Patients with acute coronary syndrome, renal dialytic insufficiency, collagen disease and cancer were not included. All patients were subjected to clinical evaluation and laboratory tests. Endothelial function of the brachial artery and carotid artery were evaluated by high-resolution ultrasound; ankle-brachial index and computed tomography for coronary determination of calcium score were also performed, and non-HDL cholesterol and TG/HDL-c ratio were calculated. All patients were subjected to coronary angiography at the request of the assistant physician. We considered patients without an obstructive lesion (< 29% stenosis) demonstrated by coronary angiography to be normal. RESULTS: Univariate analysis showed that calcium score, HDL-c, TG/HDL ratio and IMT were significantly correlated with the Friesinger index. However, multivariate analysis indicated that only calcium score and low HDL-c levels correlated significantly with the extension of CAD. On the other hand, hs-CRP, LDL-c, flow-mediated dilation, and Framingham score did not correlate with the Friesinger index. ROC analysis showed that calcium score, HDL-c and TG-HDL ratio accurately predicted extensive CAD in a statistically significant manner. CONCLUSION: It is possible to approximately determine the presence and extent of CAD by non-invasive methods, especially by calcium score, HDL-c and TG/HDL-c ratio assays

  9. Arterial Obstruction on Computed Tomographic or Magnetic Resonance Angiography and Response to Intravenous Thrombolytics in Ischemic Stroke

    PubMed Central

    Mair, Grant; von Kummer, Rüdiger; Adami, Alessandro; White, Philip M.; Adams, Matthew E.; Yan, Bernard; Demchuk, Andrew M.; Farrall, Andrew J.; Sellar, Robin J.; Sakka, Eleni; Palmer, Jeb; Perry, David; Lindley, Richard I.; Sandercock, Peter A.G.

    2017-01-01

    Background and Purpose— Computed tomographic angiography and magnetic resonance angiography are used increasingly to assess arterial patency in patients with ischemic stroke. We determined which baseline angiography features predict response to intravenous thrombolytics in ischemic stroke using randomized controlled trial data. Methods— We analyzed angiograms from the IST-3 (Third International Stroke Trial), an international, multicenter, prospective, randomized controlled trial of intravenous alteplase. Readers, masked to clinical, treatment, and outcome data, assessed prerandomization computed tomographic angiography and magnetic resonance angiography for presence, extent, location, and completeness of obstruction and collaterals. We compared angiography findings to 6-month functional outcome (Oxford Handicap Scale) and tested for interactions with alteplase, using ordinal regression in adjusted analyses. We also meta-analyzed all available angiography data from other randomized controlled trials of intravenous thrombolytics. Results— In IST-3, 300 patients had prerandomization angiography (computed tomographic angiography=271 and magnetic resonance angiography=29). On multivariable analysis, more extensive angiographic obstruction and poor collaterals independently predicted poor outcome (P<0.01). We identified no significant interaction between angiography findings and alteplase effect on Oxford Handicap Scale (P≥0.075) in IST-3. In meta-analysis (5 trials of alteplase or desmoteplase, including IST-3, n=591), there was a significantly increased benefit of thrombolytics on outcome (odds ratio>1 indicates benefit) in patients with (odds ratio, 2.07; 95% confidence interval, 1.18–3.64; P=0.011) versus without (odds ratio, 0.88; 95% confidence interval, 0.58–1.35; P=0.566) arterial obstruction (P for interaction 0.017). Conclusions— Intravenous thrombolytics provide benefit to stroke patients with computed tomographic angiography or magnetic

  10. Methods and algorithms for optical coherence tomography-based angiography: a review and comparison

    NASA Astrophysics Data System (ADS)

    Zhang, Anqi; Zhang, Qinqin; Chen, Chieh-Li; Wang, Ruikang K.

    2015-10-01

    Optical coherence tomography (OCT)-based angiography is increasingly becoming a clinically useful and important imaging technique due to its ability to provide volumetric microvascular networks innervating tissue beds in vivo without a need for exogenous contrast agent. Numerous OCT angiography algorithms have recently been proposed for the purpose of contrasting microvascular networks. A general literature review is provided on the recent progress of OCT angiography methods and algorithms. The basic physics and mathematics behind each method together with its contrast mechanism are described. Potential directions for future technical development of OCT based angiography is then briefly discussed. Finally, by the use of clinical data captured from normal and pathological subjects, the imaging performance of vascular networks delivered by the most recently reported algorithms is evaluated and compared, including optical microangiography, speckle variance, phase variance, split-spectrum amplitude decorrelation angiography, and correlation mapping. It is found that the method that utilizes complex OCT signal to contrast retinal blood flow delivers the best performance among all the algorithms in terms of image contrast and vessel connectivity. The purpose of this review is to help readers understand and select appropriate OCT angiography algorithm for use in specific applications.

  11. Methods and algorithms for optical coherence tomography-based angiography: a review and comparison

    PubMed Central

    Zhang, Anqi; Zhang, Qinqin; Chen, Chieh-Li; Wang, Ruikang K.

    2015-01-01

    Abstract. Optical coherence tomography (OCT)-based angiography is increasingly becoming a clinically useful and important imaging technique due to its ability to provide volumetric microvascular networks innervating tissue beds in vivo without a need for exogenous contrast agent. Numerous OCT angiography algorithms have recently been proposed for the purpose of contrasting microvascular networks. A general literature review is provided on the recent progress of OCT angiography methods and algorithms. The basic physics and mathematics behind each method together with its contrast mechanism are described. Potential directions for future technical development of OCT based angiography is then briefly discussed. Finally, by the use of clinical data captured from normal and pathological subjects, the imaging performance of vascular networks delivered by the most recently reported algorithms is evaluated and compared, including optical microangiography, speckle variance, phase variance, split-spectrum amplitude decorrelation angiography, and correlation mapping. It is found that the method that utilizes complex OCT signal to contrast retinal blood flow delivers the best performance among all the algorithms in terms of image contrast and vessel connectivity. The purpose of this review is to help readers understand and select appropriate OCT angiography algorithm for use in specific applications. PMID:26473588

  12. Indocyanine green angiography for examining the normal ocular fundus in dogs.

    PubMed

    Wakaiki, Shinsuke; Maehara, Seiya; Abe, Reona; Tsuzuki, Keiko; Igarashi, Osamu; Saito, Akihiko; Itoh, Norihiko; Yamashita, Kazuto; Izumisawa, Yasuharu

    2007-05-01

    In dogs, a variety of diseases of the retina and choroid have been reported, either separately or concomitantly; however, the canine choroid is difficult to evaluate by veterinary techniques currently available. Indocyanine green (ICG) angiography is widely used in human ophthalmology, but has not been investigated for use in canine ophthalmology. The aim of this study was to apply a new approach to ICG angiography and compare the resulting angiograms with fluorescein (FLUO) angiograms of the ocular fundus in dogs. With a fundus camera equipped with an infrared-sensitive charged coupled device (CCD), we performed angiography on eight healthy beagles under inhalation anesthesia. ICG angiography enabled clear visualization of the choroidal vasculature, whereas FLUO angiography showed only the retinal vessels. At 8.4 +/- 3.6 sec after administration of ICG dye into the cephalic vein, the choroidal arteries could be seen extending radially from the optic disc, then the choroidal veins became apparent at 10.2 +/- 4.1 sec, coursing alongside the choroidal arteries. Gradual fading of the choroidal vessels began 13.2 +/- 2.2 min after the dye was administered, and overall diffuse fluorescence of the fundus appeared. Diffuse fluorescence of the fundus continued after the choroidal vessels and optic disc faded at about 58.3 +/- 5.3 min from administration of the dye. In conclusion, ICG angiography provides clear resolution and is reliable and simple, thus offering promise as a diagnostic aid for clinical evaluation of the choroid in dogs.

  13. CT angiography after 20 years: a transformation in cardiovascular disease characterization continues to advance.

    PubMed

    Rubin, Geoffrey D; Leipsic, Jonathon; Joseph Schoepf, U; Fleischmann, Dominik; Napel, Sandy

    2014-06-01

    Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5-15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography.

  14. Diagnostic Performance of First-Pass Myocardial Perfusion Imaging without Stress with Computed Tomography (CT) Compared with Coronary CT Angiography Alone, with Fractional Flow Reserve as the Reference Standard.

    PubMed

    Osawa, Kazuhiro; Miyoshi, Toru; Miki, Takashi; Koyama, Yasushi; Sato, Shuhei; Kanazawa, Susumu; Ito, Hiroshi

    2016-01-01

    Coronary computed tomography angiography (CCTA) in combination with first-pass CT myocardial perfusion imaging (MPI) has a better diagnostic performance than CCTA alone, compared with invasive coronary angiography as the reference standard. The aim of this study was to investigate the additional diagnostic value of first-pass CT-MPI without stress for detecting hemodynamic significance of coronary stenosis, compared with invasive fractional flow reserve (FFR). We recruited 53 patients with suspected coronary artery disease undergoing both CCTA and first-pass CT-MPI without stress and invasive FFR, and 75 vessels were analyzed. We used the same raw data for CCTA and CT-MPI. First-pass CT-MPI was reconstructed by examining the diastolic signal densities as a bull's eye map. Invasive FFR <0.8 was considered as positive. On per-vessel analysis, the area under the receiver operating characteristic curve for CCTA plus first-pass CT-MPI and CCTA alone was 0.81 (0.73-0.90) and 0.70 (0.61-0.81), respectively (P = 0.036). CCTA plus first-pass CT-MPI without stress showed 0.73 sensitivity, 0.74 specificity, 0.53 positive predictive value, and 0.87 negative predictive value for detecting hemodynamically significant coronary stenosis. First-pass CT-MPI without stress correctly reclassified 38% of CCTA false-positive vessels as true negative. First-pass CT-MPI without stress combined with CCTA demonstrated excellent diagnostic accuracy, compared with invasive FFR as the reference standard. This technique could complement CCTA for diagnosis of coronary artery disease.

  15. Spiral computed tomography angiography (SCTA) and color coded duplex ultrasound (CCDUS): two complementary diagnostic techniques for assessment of extracranial cerebral artery stenosis.

    PubMed

    Scaroni, Reana; Cardaioli, Gabriela; Pelliccioli, Gian Piero; Gallai, Virgilio

    2002-01-01

    Atherosclerotic lesions of the extracranial cerebral arteries account for ischemic stroke in over half of all cases. The risk of stroke associated with symptomatic carotid artery disease is related to the severity of the stenosis. Results of the two major clinical trials, North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST), showed that patients with symptomatic carotid artery disease may benefit from carotid endarterectomy. Therefore, detection and quantification of stenosis are essential. Discrepancies in the angiographic criteria used in both NASCET and ECST trials resulted in continued controversy about the most accurate method of measuring carotid artery stenosis. Moreover, to avoid complications related to the angiography procedure, a good evaluation of vessel wall and plaque composition need to be considered. Both SCTA and CCDUS are non invasive techniques that could overcome angiographic complications and give detailed information on stenosis grading and plaque characteristics. They have been used to evaluate carotid stenosis as a single or combined methods.

  16. Minimally invasive procedures

    PubMed Central

    Baltayiannis, Nikolaos; Michail, Chandrinos; Lazaridis, George; Anagnostopoulos, Dimitrios; Baka, Sofia; Mpoukovinas, Ioannis; Karavasilis, Vasilis; Lampaki, Sofia; Papaiwannou, Antonis; Karavergou, Anastasia; Kioumis, Ioannis; Pitsiou, Georgia; Katsikogiannis, Nikolaos; Tsakiridis, Kosmas; Rapti, Aggeliki; Trakada, Georgia; Zissimopoulos, Athanasios; Zarogoulidis, Konstantinos

    2015-01-01

    Minimally invasive procedures, which include laparoscopic surgery, use state-of-the-art technology to reduce the damage to human tissue when performing surgery. Minimally invasive procedures require small “ports” from which the surgeon inserts thin tubes called trocars. Carbon dioxide gas may be used to inflate the area, creating a space between the internal organs and the skin. Then a miniature camera (usually a laparoscope or endoscope) is placed through one of the trocars so the surgical team can view the procedure as a magnified image on video monitors in the operating room. Specialized equipment is inserted through the trocars based on the type of surgery. There are some advanced minimally invasive surgical procedures that can be performed almost exclusively through a single point of entry—meaning only one small incision, like the “uniport” video-assisted thoracoscopic surgery (VATS). Not only do these procedures usually provide equivalent outcomes to traditional “open” surgery (which sometimes require a large incision), but minimally invasive procedures (using small incisions) may offer significant benefits as well: (I) faster recovery; (II) the patient remains for less days hospitalized; (III) less scarring and (IV) less pain. In our current mini review we will present the minimally invasive procedures for thoracic surgery. PMID:25861610

  17. Jugular venous reflux on magnetic resonance angiography and radionuclide venography

    PubMed Central

    Okada, Tomohisa; Okuchi, Sachi; Yamamoto, Akira; Kanagaki, Mitsunori; Fujimoto, Koji; Togashi, Kaori

    2016-01-01

    Background The relationship between the signal from retrograde venous flow on magnetic resonance angiography (MRA) and retrograde upward flow from the left brachiocephalic vein has not been explored. Purpose To reveal the frequency of jugular venous reflux using MRA and nuclear venography in patients being evaluated for cerebral volume and blood flow. Material and Methods A total of 229 patients with cognitive disturbance who had undergone brain magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) on the same day to evaluate cerebral blood flow were evaluated. Jugular venous reflux was measured on MRA and nuclear venography, which was conducted just after injection of N-isopropyl-123I-p-iodoamphetamine for the SPECT study. Results MRA showed jugular reflux in seven patients on the right side, and in 22 on the left. Nuclear venography showed jugular reflux in six patients on the right side, and in 20 on the left. Conclusion Jugular venous reflux was observed mostly on the left side. Retrograde flow was observed on both MRA and nuclear venography in half of the cases, with the rest only on one of the modalities. PMID:27994882

  18. Pediatric computed tomographic angiography: imaging the cardiovascular system gently.

    PubMed

    Hellinger, Jeffrey C; Pena, Andres; Poon, Michael; Chan, Frandics P; Epelman, Monica

    2010-03-01

    Whether congenital or acquired, timely recognition and management of disease is imperative, as hemodynamic alterations in blood flow, tissue perfusion, and cellular oxygenation can have profound effects on organ function, growth and development, and quality of life for the pediatric patient. Ensuring safe computed tomographic angiography (CTA) practice and "gentle" pediatric imaging requires the cardiovascular imager to have sound understanding of CTA advantages, limitations, and appropriate indications as well as strong working knowledge of acquisition principles and image post processing. From this vantage point, CTA can be used as a useful adjunct along with the other modalities. This article presents a summary of dose reduction CTA methodologies along with techniques the authors have employed in clinical practice to achieve low-dose and ultralow-dose exposure in pediatric CTA. CTA technical principles are discussed with an emphasis on the low-dose methodologies and safe contrast medium delivery strategies. Recommended parameters for currently available multidetector-row computed tomography scanners are summarized alongside recommended radiation and contrast medium parameters. In the second part of the article an overview of pediatric CTA clinical applications is presented, illustrating low-dose and ultra-low dose techniques, with an emphasis on the specific protocols.

  19. Recurrent contrast-induced encephalopathy following coronary angiography.

    PubMed

    Spina, Roberto; Simon, Neil; Markus, Romesh; Muller, David W M; Kathir, Krishna

    2017-02-01

    Contrast-induced encephalopathy (CIE) is an acute and reversible neurological disturbance associated with the intra-arterial administration of iodinated contrast medium during cardiac catheterisation. It may manifest with encephalopathy, motor and sensory disturbances; vision disturbances, including cortical blindness, ophthalmoplegia, aphasia; and seizures. Disruption of the blood-brain barrier and direct neuronal toxicity are believed to be implicated in the pathophysiology of the syndrome. Symptoms appear soon after contrast administration and resolve completely within 24-48 h. Risk factors may include hypertension, diabetes mellitus, renal impairment, the administration of large volumes of iodinated contrast, percutaneous coronary intervention or selective angiography of internal mammary grafts and previous adverse reaction to iodinated contrast. On cerebral imaging, CIE may mimic subarachnoid haemorrhage or cerebral ischaemia, but imaging may be normal. Prognosis is excellent with supportive management alone. CIE may recur, but re-challenge with iodinated contrast without adverse effects has been documented. CIE is a diagnosis of exclusion and is an important clinical entity to consider in the differential diagnosis of stroke following cardiac catheterisation. Physicians should be aware of it and consider it prior to initiating thrombolysis.

  20. Coronary MR Angiography at 3T During Diastole and Systole

    PubMed Central

    Gharib, Ahmed M.; Herzka, Daniel A.; Ustun, Ali O.; Desai, Milind Y.; Locklin, Julia; Pettigrew, Roderic I.; Stuber, Matthias

    2016-01-01

    Purpose To investigate the impact of end-systolic imaging on quality of right coronary magnetic resonance angiography (MRA) in comparison to diastolic and to study the effect of RR interval variability on image quality. Materials and Methods The right coronary artery (RCA) of 10 normal volunteers was imaged at 3T using parallel imaging (sensitivity encoding [SENSE]). Navigator-gated three-dimensional (3D) gradient echo was used three times: 1) end-systolic short acquisition (SS): 35-msec window; 2) diastolic short (DS): middiastolic acquisition using 35-msec window; and 3) diastolic long (DL): 75-msec diastolic acquisition window. Vectorcardiogram (VCG) data was used to analyze RR variability. Vessel sharpness, length, and diameter were compared to each other and correlated with RR variability. Blinded qualitative image scores of the images were compared. Results Quantitative and qualitative parameters were not significantly different and showed no significant correlation with RR variability. Conclusion Imaging the RCA at 3T during the end-systolic rest period using SENSE is possible without significant detrimental effect on image quality. Breaking away from the standard of imaging only during diastole can potentially improve image quality in tachycardic patients or used for simultaneous imaging during both periods in a single scan. PMID:17896391

  1. Motion compensation in digital subtraction angiography using graphics hardware.

    PubMed

    Deuerling-Zheng, Yu; Lell, Michael; Galant, Adam; Hornegger, Joachim

    2006-07-01

    An inherent disadvantage of digital subtraction angiography (DSA) is its sensitivity to patient motion which causes artifacts in the subtraction images. These artifacts could often reduce the diagnostic value of this technique. Automated, fast and accurate motion compensation is therefore required. To cope with this requirement, we first examine a method explicitly designed to detect local motions in DSA. Then, we implement a motion compensation algorithm by means of block matching on modern graphics hardware. Both methods search for maximal local similarity by evaluating a histogram-based measure. In this context, we are the first who have mapped an optimizing search strategy on graphics hardware while paralleling block matching. Moreover, we provide an innovative method for creating histograms on graphics hardware with vertex texturing and frame buffer blending. It turns out that both methods can effectively correct the artifacts in most case, as the hardware implementation of block matching performs much faster: the displacements of two 1024 x 1024 images can be calculated at 3 frames/s with integer precision or 2 frames/s with sub-pixel precision. Preliminary clinical evaluation indicates that the computation with integer precision could already be sufficient.

  2. Computed Tomography Angiography of Carotid Arteries and Vertebrobasilar System

    PubMed Central

    Kramer, Manuel; Ellmann, Stephan; Allmendinger, Thomas; Eller, Achim; Kammerer, Ferdinand; May, Matthias S.; Baigger, João F.; Uder, Michael; Lell, Michael M.

    2015-01-01

    Abstract Computed tomography angiography (CTA) of carotid arteries and vertebrobasilar system is a standardized procedure with excellent image quality, but radiation exposure remains a matter of concern. The aim of this study is to examine to what extent radiation dose can be lowered in relation to a standard protocol by simulating examinations with lower tube currents applying a dedicated software. Lower tube current was simulated by a dedicated noise insertion and reconstruction software (ReconCT). In a phantom study, true scans were performed with different dose protocols and compared to the results of simulated dose reductions of the same degree, respectively. In a patient study, 30 CTAs of supra-aortic vessels were reconstructed at a level of 100%, 75%, 50%, and 25% of the initial dose. Objective and subjective image analyses were performed. No significant noise differences between true scans and simulated scans of mimicked contrasted vessels were found. In the patient study, the quality scores of the 4 dose groups differed statistically significant; this difference vanished for the comparison of the 100% and 75% datasets after dichotomization into the categories of diagnostic and nondiagnostic image quality (P = .50). This study suggests an easy-to-implement method of simulating CTAs of carotid arteries and vertebrobasilar system with lower tube current for dose reduction by artificially adding noise to the original raw data. Lowering the radiation dose in a moderate extent to 75% of the original dose levels does not significantly alter the diagnostic image quality. PMID:26131822

  3. 64-MULTIDETECTOR COMPUTED TOMOGRAPHIC ANGIOGRAPHY OF THE CANINE CORONARY ARTERIES

    PubMed Central

    Drees, Randi; Frydrychowicz, Alex; Reeder, Scott B.; Pinkerton, Marie E.; Johnson, Rebecca

    2012-01-01

    Canine coronary artery angiography (CTA) was performed in four anesthetized healthy dogs using 64-multi-detector computed tomography. Esmolol, a β-1 adrenergic receptor antagonist, and sodium nitroprusside, an arteriolar and venous dilator, were administered to enhance visualization of the coronary arteries by reducing heart rate and creating vasodilation. The left main coronary artery with its three main branches and the right coronary artery were visualized and subdivided in 13 segments for evaluation. Optimal reconstruction interval, expressed as percentage of the R-to-R interval, was determined at 5% in 2.9%, 35% in 1%, 75% in 21.2%, 85% in 43.3%, and 95% in 31.7% of the segments. Overall image quality was good in 41.3% of the segments and excellent in 14.4%. There was blur in 98.1%, motion in 17.3%, and stair step in 6.7% of the evaluated segments, but these artifacts did not interfere with anatomic depiction of the arteries. Cross-sectional anatomy of the coronary arteries as evaluated from the coronary CTA agreed well with gross anatomic evaluation and published information. The use of esmolol did not lead to the target heart rate of 60–65 beats/min. Nitroprusside had no significant effect on visualized length or diameter of the coronary artery branches. Coronary CTA is useful for the anatomic depiction of coronary artery branches in the dog. PMID:21521398

  4. How accurate are we in sending patients to angiography?

    PubMed

    Neves, Marta; Ponce, Pedro; Maia, Pedro; Neves, Fernando

    2014-01-01

    Physical examination (PE), and surveillance and monitoring techniques should be a core part of standard care provided to hemodialysis patients. This study aimed to define which referral criteria within a vascular access (VA) program were associated with indication for therapeutic endovascular intervention (EI). Retrospective study at two vascular centers, considering 1265 procedures between 1 November 2012 and 30 November 2013. All 617 arteriovenous fistulas (AVFs) and 648 arteriovenous grafts (AVGs) referred for angiography were enrolled. Each population was divided into two groups regarding absence (group 1) or presence (group 2) of a significant lesion on the angiogram, contemplating formal indication for EI. On multivariate analysis, factors independently associated with presence of a significant lesion in AVFs were referral due to increased dynamic venous pressure (p = 0.01), suspected stenosis by abnormal PE (p = 0.019), confirmed reduction in access flow rate (p = 0.003), and mean Kt/V < 1.4 (p = 0.004). In AVGs, although multivariate analysis did not find independent association of studied factors with presence of significant stenoses, 97.2% of the exams revealed relevant lesions previously suspected clinically. Aside from surveillance strategies, monitoring strategies including routine PE of the VA are imperative as an integral part of evaluation, especially in AVFs.

  5. NSLS transvenous coronary angiography beamline upgrade and advanced technology initiatives

    SciTech Connect

    Gmuer, N.F.; Chapman, D.; Thomlinson, W.; Thompson, A.C.; Lavender, W.M.; Scalia, K.; Malloy, N.; Mangano, J.; Jacob, J.

    1994-11-01

    Since October 1990, the coronary anatomies of a total of 16 patients (male and female) have been imaged at the National Synchrotron Light Source (NSLS) as part of the Dual Energy Digital Subtraction Transvenous Coronary Angiography research program. This program takes place in the Synchrotron Medical Research Facility (SMERF) on the X17B2 wiggler beamline. Encouraged by the success of the initial patient images, the NSLS has recently embarked on an ambitious upgrade effort. This effort covers all aspects of the X17B2 beamline and includes improved radiation shielding, a Laue monochromator assembly, a computer-controlled 5 motion patient scanning chair assembly, a fast low-noise image acquisition system, and a modularized patient safety system. These improvements will allow major advances in imaging patients based on ECG signal gating and multiple view imaging. Two advanced technology initiatives are underway with industrial collaborators. One will develop real-time image acquisition and display of the subtracted digital images. The second will develop a compact x-ray source for medical imaging. The source will be a linear electron accelerator creating characteristic radiation line emissions.

  6. NSLS transvenous coronary angiography beamline upgrade and advanced technology initiatives

    SciTech Connect

    Gmuer, N.F.; Chapman, D.; Thomlinson, W. ); Thompson, A.C. ); Lavender, W.M. ); Scalia, K.; Malloy, N. ); Mangano, J.; Jacob, J. )

    1995-02-01

    Since October 1990, the coronary anatomies of a total of 16 patients (male and female) have been imaged at the National Synchrotron Light Source (NSLS) as part of the Dual Energy Digital Subtraction Transvenous Coronary Angiography research program. This program takes place in the Synchrotron Medical Research Facility (SMERF) on the X17B2 wiggler beamline. Encouraged by the success of the initial patient images, the NSLS has recently embarked on an ambitious upgrade effort. This effort covers all aspects of the X17B2 beamline and includes improved radiation shielding, a Laue monochromator assembly, a computer-controlled five motion patient scanning chair assembly, a fast low-noise image acquisition system, and a modularized patient safety system. These improvements will allow major advances in imaging patients based on ECG signal gating and multiple view imaging. Two advanced technology initiatives are underway with industrial collaborators. One will develop real-time image acquisition and display of the subtracted digital images. The second will develop a compact x-ray source of medical imaging. The source will be a linear electron accelerator creating characteristic radiation line emissions.

  7. Estimation of myocardial volume at risk from CT angiography

    NASA Astrophysics Data System (ADS)

    Zhu, Liangjia; Gao, Yi; Mohan, Vandana; Stillman, Arthur; Faber, Tracy; Tannenbaum, Allen

    2011-03-01

    The determination of myocardial volume at risk distal to coronary stenosis provides important information for prognosis and treatment of coronary artery disease. In this paper, we present a novel computational framework for estimating the myocardial volume at risk in computed tomography angiography (CTA) imagery. Initially, epicardial and endocardial surfaces, and coronary arteries are extracted using an active contour method. Then, the extracted coronary arteries are projected onto the epicardial surface, and each point on this surface is associated with its closest coronary artery using the geodesic distance measurement. The likely myocardial region at risk on the epicardial surface caused by a stenosis is approximated by the region in which all its inner points are associated with the sub-branches distal to the stenosis on the coronary artery tree. Finally, the likely myocardial volume at risk is approximated by the volume in between the region at risk on the epicardial surface and its projection on the endocardial surface, which is expected to yield computational savings over risk volume estimation using the entire image volume. Furthermore, we expect increased accuracy since, as compared to prior work using the Euclidean distance, we employ the geodesic distance in this work. The experimental results demonstrate the effectiveness of the proposed approach on pig heart CTA datasets.

  8. Investigation of temporal resolution required for CT coronary angiography

    NASA Astrophysics Data System (ADS)

    Ohashi, Kazuya; Ichikawa, Katsuhiro; Kawai, Tatsuya; Shibamoto, Yuta

    2012-03-01

    Sub-second multi-detector computed tomography systems (MDCTs) offer great potentials for improving cardiac imaging. However, since the temporal resolution of such CT systems is not sufficient, blurring and artifacts produced by fast cardiac motion are still problematic. The purposes of this study were to investigate the accurate method for measurement of temporal resolution (TR) of the cardiac CT and required TR for obtaining better CT coronary angiography (CTCA). We employed a dual source CT system (Somatom Definition, Siemens), which has various temporal resolution modes (83, 125, and 165 msec) for electro-cardiogram (ECG)-gated scanning. The temporal sensitivity profiles (TSPs) were measured by a new method using temporal impulse generated by metal ball (impulse method). The CTCA images of 200 patients with heart rates (HRs) ranging from 36 to 117 beat per minute (bpm) were visually evaluated using a 4-point scale. The 165-msec TR mode, which is mostly available on recent MDCTs, showed a sufficient image quality only at low HR (<= 60 bpm) for all 3 arteries. The image quality of 125-msec TR mode was acceptable at low to intermediate HRs (< 80 bpm) for LADs and LCXs, and insufficient for the RCAs in cases with HR more than 71 bpm. The 83-msec TR mode demonstrated excellent image quality except for cases with very quick motion of the RCAs at a high HR (>80 bpm).

  9. Digital Subtraction MR Angiography Roadmapping for Magnetic Steerable Catheter Tracking

    PubMed Central

    Martin, Alastair J.; Lillaney, Prasheel; Saeed, Maythem; Losey, Aaron D.; Settecase, Fabio; Evans, Lee; Arenson, Ronald L.; Wilson, Mark W.; Hetts, Steven W.

    2014-01-01

    Purpose To develop a high temporal resolution MR imaging technique that could be employed with magnetically-assisted remote control (MARC) endovascular catheters. Materials and Methods A technique is proposed based on selective intra-arterial injections of dilute MR contrast at the beginning of a fluoroscopic MR angiography acquisition. The initial bolus of contrast is used to establish a vascular roadmap upon which MARC catheters can be tracked. The contrast to noise ratio of the achieved roadmap was assessed in phantoms and in a swine animal model. The ability of the technique to permit navigation of activated MARC catheters through arterial branch points was evaluated. Results The roadmapping mode proved effective in phantoms for tracking objects and achieved a contrast to noise ratio of 35.7 between the intra and extra-vascular space. In vivo, the intra-arterial enhancement strategy produced roadmaps with a contrast to noise ratio of 42.0. The artifact produced by MARC catheter activation provided signal enhancement patterns on the roadmap that experienced interventionalists could track through vascular structures. Conclusion A roadmapping approach with intra-arterial CE-MRA is introduced for navigating the MARC catheter. The technique mitigates the artifact produced by the MARC catheter, greatly limits the required SAR, permits regular roadmap updates due to the low contrast agent requirements, and proved effective in the in vivo setting. PMID:24797218

  10. Invasive Bordetella holmesii infections.

    PubMed

    Fishbain, Joel T; Riederer, Kathleen; Sawaf, Hadi; Mody, Rupal

    2015-02-01

    Bordetella holmesii is a rare cause of invasive human disease. The fastidious and unusual nature of this organism makes routine isolation and identification challenging. We report two cases of B. holmesii bacteremia that were rapidly identified by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) when standard techniques failed to provide speciation. There are no current standards for susceptibility testing or treatment recommendations. The rare occurrence and challenges in identifying this pathogen led us to perform a comprehensive review of the epidemiology, clinical presentations, and treatment options for this potentially invasive pathogen.

  11. Intracellular Parasite Invasion Strategies

    NASA Astrophysics Data System (ADS)

    Sibley, L. D.

    2004-04-01

    Intracellular parasites use various strategies to invade cells and to subvert cellular signaling pathways and, thus, to gain a foothold against host defenses. Efficient cell entry, ability to exploit intracellular niches, and persistence make these parasites treacherous pathogens. Most intracellular parasites gain entry via host-mediated processes, but apicomplexans use a system of adhesion-based motility called ``gliding'' to actively penetrate host cells. Actin polymerization-dependent motility facilitates parasite migration across cellular barriers, enables dissemination within tissues, and powers invasion of host cells. Efficient invasion has brought widespread success to this group, which includes Toxoplasma, Plasmodium, and Cryptosporidium.

  12. Radionuclide angiography and blood pool imaging to assess skin ulcer healing prognosis in patients with peripheral vascular disease

    SciTech Connect

    Alazraki, N.; Lawrence, P.F.; Syverud, J.B.

    1984-01-01

    Several non-invasive diagnostic techniques including segmental limb blood pressures, skin fluoresence, and photo plethysmography, have been evaluated as predictors of skin ulcer healing in patients with peripheral vascular disease, but none are widely used. Using 20mCi of Tc-99m phosphate compounds, four phase bone scans were obtained, including (1) radionuclide angiogram (2) blood pool image (3) 2 hour and 4-6 hour static images and (4) 24 hour static delayed images. The first two phases were used to assess vacularity to the region of distal extremity ulceration; the last two phases evaluated presence or absence of osteomyelitis. Studies were performed in 30 patients with non-healing ulcers of the lower extremities. Perfusion to the regions of ulceration on images was graded as normal, increased, or reduced with respect to the opposite (presumed normal) limb or some other normal reference area. Hypervascular response was interpreted as good prognosis for healing unless osteomyelitis was present. Clinicians followed patients for 14 days to assess limb healing with optimum care. If there was no improvement, angiography and/or surgery (reconstructive surgery, sympathectomy, or amputation) was done. Results showed: sensitivity for predicting ulcer healing was 94%, specificity 89%. Patients who failed to heal their ulcers showed reduced perfusion, no hypervascular response, or osteomyelitis. Microcirculatory adequacy for ulcer healing appear predictable by this technique.

  13. Over-invasion by functionally equivalent invasive species.

    PubMed

    Russell, James C; Sataruddin, Nurul S; Heard, Allison D

    2014-08-01

    Multiple invasive species have now established at most locations around the world, and the rate of new species invasions and records of new invasive species continue to grow. Multiple invasive species interact in complex and unpredictable ways, altering their invasion success and impacts on biodiversity. Incumbent invasive species can be replaced by functionally similar invading species through competitive processes; however the generalized circumstances leading to such competitive displacement have not been well investigated. The likelihood of competitive displacement is a function of the incumbent advantage of the resident invasive species and the propagule pressure of the colonizing invasive species. We modeled interactions between populations of two functionally similar invasive species and indicated the circumstances under which dominance can be through propagule pressure and incumbent advantage. Under certain circumstances, a normally subordinate species can be incumbent and reject a colonizing dominant species, or successfully colonize in competition with a dominant species during simultaneous invasion. Our theoretical results are supported by empirical studies of the invasion of islands by three invasive Rattus species. Competitive displacement is prominent in invasive rats and explains the replacement of R. exulans on islands subsequently invaded by European populations of R. rattus and R. norvegicus. These competition outcomes between invasive species can be found in a broad range of taxa and biomes, and are likely to become more common. Conservation management must consider that removing an incumbent invasive species may facilitate invasion by another invasive species. Under very restricted circumstances of dominant competitive ability but lesser impact, competitive displacement may provide a novel method of biological control.

  14. Invasion triangle: an organizational framework for species invasion

    PubMed Central

    Perkins, Lora B; Leger, Elizabeth A; Nowak, Robert S

    2011-01-01

    Species invasion is a complex, multifactor process. To encapsulate this complexity into an intuitively appealing, simple, and straightforward manner, we present an organizational framework in the form of an invasion triangle. The invasion triangle is an adaptation of the disease triangle used by plant pathologists to help envision and evaluate interactions among a host, a pathogen, and an environment. Our modification of this framework for invasive species incorporates the major processes that result in invasion as the three sides of the triangle: (1) attributes of the potential invader; (2) biotic characteristics of a potentially invaded site; and (3) environmental conditions of the site. The invasion triangle also includes the impact of external influences on each side of the triangle, such as climate and land use change. This paper introduces the invasion triangle, discusses how accepted invasion hypotheses are integrated in this framework, describes how the invasion triangle can be used to focus research and management, and provides examples of application. The framework provided by the invasion triangle is easy to use by both researchers and managers and also applicable at any level of data intensity, from expert opinion to highly controlled experiments. The organizational framework provided by the invasion triangle is beneficial for understanding and predicting why species are invasive in specific environments, for identifying knowledge gaps, for facilitating communication, and for directing management in regard to invasive species. PMID:22393528

  15. Magnetic resonance angiography for the evaluation of vascular injury in knee dislocations.

    PubMed

    Tocci, Stephen L; Heard, Wendell M R; Fadale, Paul D; Brody, Jeffrey M; Born, Christopher

    2010-12-01

    Knee dislocations can cause extensive soft tissue disruption including vascular insufficiency to the leg secondary to popliteal artery injury. Physical exam may miss vascular injury and possible late occlusion, but there is controversy regarding use of angiography to evaluate patients after dislocation. Magnetic resonance angiography (MRA) has been shown to be equally effective as angiography in evaluating vascular injury and to have fewer complications than angiography. Patients with knee dislocations routinely receive magnetic resonance imaging (MRI) to assess ligament integrity. The purpose of our study was to determine whether it may be prudent and convenient to obtain an MR angiogram at the same time as an MRI scan, with less morbidity and discomfort than with conventional angiography. Sixteen patients with frank and occult knee dislocations were prospectively evaluated over 2 years. After reduction, a physical exam was performed including ankle brachial index (ABI). With ABI < 0.90, emergent vascular surgery consult and angiogram was performed. Patients with ABI > 0.90 were observed for 3 days with serial physical exams, and MRI/MRA was performed as soon as possible. Sixteen dislocations were identified. Two of 16 (12.5%) had abnormal ABIs and received an angiogram and subsequent revascularization. Two had normal exams, but refused MRA. Twelve had normal exams and received MRI/MRA showing a normal popliteal artery with no adverse events. ABI had 100% sensitivity for vascular injury; however, there remains concern among treating surgeons about missing an occult injury such as an intimal tear. Because MRA has been shown to be as accurate and useful as angiography, we may be able to evaluate ligamentous and vascular injury simultaneously with less morbidity than that with conventional angiography.

  16. Early Primary Invasion Scientists

    ERIC Educational Resources Information Center

    Spellman, Katie V.; Villano, Christine P.

    2011-01-01

    "We really need to get the government involved," said one student, holding his graph up to USDA scientist Steve Seefeldt. Dr. Steve studies methods to control "invasive" plants, plants that have been introduced to an area by humans and have potential to spread rapidly and negatively affect ecosystems. The first grader and his…

  17. Minimally invasive valve surgery.

    PubMed

    Woo, Y Joseph

    2009-08-01

    Traditional cardiac valve replacement surgery is being rapidly supplanted by innovative, minimally invasive approaches toward the repair of these valves. Patients are experiencing benefits ranging from less bleeding and pain to faster recovery and greater satisfaction. These operations are proving to be safe, highly effective, and durable, and their use will likely continue to increase and become even more widely applicable.

  18. Invasion percolation with memory

    SciTech Connect

    Kharabaf, H.; Yortsos, Y.C.

    1997-06-01

    Motivated by the problem of finding the minimum threshold path (MTP) in a lattice of elements with random thresholds {tau}{sub i}, we propose a new class of invasion processes, in which the front advances by minimizing or maximizing the measure S{sub n}={summation}{sub i}{tau}{sub i}{sup n} for real n. This rule assigns long-time memory to the invasion process. If the rule minimizes S{sub n} (case of minimum penalty), the fronts are stable and connected to invasion percolation in a gradient [J. P. Hulin, E. Clement, C. Baudet, J. F. Gouyet, and M. Rosso, Phys. Rev. Lett. {bold 61}, 333 (1988)] but in a correlated lattice, with invasion percolation [D. Wilkinson and J. F. Willemsen, J. Phys. A {bold 16}, 3365 (1983)] recovered in the limit {vert_bar}n{vert_bar}={infinity}. For small n, the MTP is shown to be related to the optimal path of the directed polymer in random media (DPRM) problem [T. Halpin-Healy and Y.-C. Zhang, Phys. Rep. {bold 254}, 215 (1995)]. In the large n limit, however, it reduces to the backbone of a mixed site-bond percolation cluster. The algorithm allows for various properties of the MTP and the DPRM to be studied. In the unstable case (case of maximum gain), the front is a self-avoiding random walk. {copyright} {ital 1997} {ital The American Physical Society}

  19. Application of optical coherence tomography angiography in assessment of posterior scleral reinforcement for pathologic myopia

    PubMed Central

    Mo, Jing; Duan, An-Li; Chan, Szy-Yann; Wang, Xue-Fei; Wei, Wen-Bin

    2016-01-01

    AIM To investigate the effect of posterior scleral reinforcement (PSR) on circulation of pathologic myopia eyes with posterior staphyloma by optical coherence tomography angiography (OCTA). METHODS The study included 30 pathologic myopia eyes with posterior staphyloma which underwent PSR (PSR group) for 6 to 18mo ago, and 30 age and myopia matched eyes without PSR surgery as control group. Macular, choriocapillaris and radial peripapillary capillary (RPC) flow density were measured by OCTA, and the measurements were compared between groups. RESULTS OCTA found no significant differences in macular flow density between PSR and control groups. For the superficial flow, whole enface flow density (WED), fovea density (FD), and parafoveal density (PD) were 46.55%±5.19% vs 47.29%±4.12% (P=0.542), 31.45%±6.35% vs 31.17%±4.48% (P=0.841), and 48.82%±5.66% vs 49.21%±4.15% (P=0.756) in PSR and control groups, respectively. For the deep flow, WED, FD, and PD were 52.07%±5.78% vs 53.95%±4.62% (P=0.168), 29.62%±6.55% vs 29.50%±6.38% (P=0.940), and 56.93%±6.17% vs 58.15%±5.13% (P=0.407) in PSR and control groups, respectively. The choriocapillary flow density was 61.18±3.25% in PSR group vs 60.88%±2.56% in control group (P=0.692). Also, OCTA found no significant differences in RPCs flow density between PSR and control groups. The optic disc WED, inside disc flow density and peripapillary flow density were 48.47%±4.77% vs 48.11%±4.57% (P=0.813), 45.47%±11.44% vs 46.68%±9.02% (P=0.709), 54.32%±5.29% vs 52.47%±6.62% (P=0.349) in PSR and control groups, respectively. CONCLUSION OCTA provides a non-invasive and quantitative approach for monitoring macular and papillary blood flow in pathologic myopia. PSR can not improve but may maintain the circulation of pathologic myopia eyes with posterior staphyloma. PMID:28003976

  20. Indocyanine green-based fluorescent angiography in breast reconstruction

    PubMed Central

    Chae, Michael P.; Rozen, Warren Matthew

    2016-01-01

    Background Fluorescent angiography (FA) has been useful for assessing blood flow and assessing tissue perfusion in ophthalmology and other surgical disciplines for decades. In plastic surgery, indocyanine green (ICG) dye-based FA is a relatively novel imaging technology with high potential in various applications. We review the various FA detector systems currently available and critically appraise its utility in breast reconstruction. Methods A review of the published English literature dating from 1950 to 2015 using databases, such as PubMed, Medline, Web of Science, and EMBASE was undertaken. Results In comparison to the old fluorescein dye, ICG has a superior side effect profile and can be accurately detected by various commercial devices, such as SPY Elite (Novadaq, Canada), FLARE (Curadel LLC, USA), PDE-Neo (Hamamatsu Photonics, Japan), Fluobeam 800 (Fluoptics, France), and IC-View (Pulsion Medical Systems AG, Germany). In breast reconstruction, ICG has established as a safer, more accurate tracer agent, in lieu of the traditional blue dyes, for detection of sentinel lymph nodes with radioactive isotopes (99m-Technetium). In prosthesis-based breast reconstruction, intraoperative assessment of the mastectomy skin flap to guide excision of hypoperfused areas translates to improved clinical outcomes. Similarly, in autologous breast reconstructions, FA can be utilized to detect poorly perfused areas of the free flap, evaluate microvascular anastomosis for patency, and assess SIEA vascular territory for use as an alternative free flap with minimal donor site morbidity. Conclusions ICG-based FA is a novel, useful tool for various applications in breast reconstruction. More studies with higher level of evidence are currently lacking to validate this technology. PMID:27047782

  1. Patient radiation biological risk in computed tomography angiography procedure.

    PubMed

    Alkhorayef, M; Babikir, E; Alrushoud, A; Al-Mohammed, H; Sulieman, A

    2017-02-01

    Computed tomography angiography (CTA) has become the most valuable imaging modality for the diagnosis of blood vessel diseases; however, patients are exposed to high radiation doses and the probability of cancer and other biological effects is increased. The objectives of this study were to measure the patient radiation dose during a CTA procedure and to estimate the radiation dose and biological effects. The study was conducted in two radiology departments equipped with 64-slice CT machines (Aquilion) calibrated according to international protocols. A total of 152 patients underwent brain, lower limb, chest, abdomen, and pelvis examinations. The effective radiation dose was estimated using ImPACT scan software. Cancer and biological risks were estimated using the International Commission on Radiological Protection (ICRP) conversion factors. The mean patient dose value per procedure (dose length product [DLP], mGy·cm) for all examinations was 437.8 ± 166, 568.8 ± 194, 516.0 ± 228, 581.8 ± 175, and 1082.9 ± 290 for the lower limbs, pelvis, abdomen, chest, and cerebral, respectively. The lens of the eye, uterus, and ovaries received high radiation doses compared to thyroid and testis. The overall patient risk per CTA procedure ranged between 15 and 36 cancer risks per 1 million procedures. Patient risk from CTA procedures is high during neck and abdomen procedures. Special concern should be provided to the lens of the eye and thyroid during brain CTA procedures. Patient dose reduction is an important consideration; thus, staff should optimize the radiation dose during CTA procedures.

  2. Objective Area Measurement Technique for Choroidal Neovascularization from Fluorescein Angiography

    PubMed Central

    Guthrie, Micah J.; Osswald, Christian R.; Valio, Nicole L.; Mieler, William F.; Kang-Mieler, Jennifer J.

    2014-01-01

    The purpose of this study was to develop a non-biased method of quantitatively measuring choroidal neovascularization (CNV) areas based on late-phase fluorescein angiography (FA) images. Experimental CNV was induced in Long Evans rats by laser disruption of the Bruch’s membrane. FA was performed weekly for 5 weeks. Multi-Otsu thresholding (MOT) was used to quantify CNV in late-phase FA images from both experimental rodent CNV and wet age-related macular degeneration patients (wAMD). Images were automatically thresholded into three levels based on the image histogram, with the highest level containing CNV. To determine the technique’s ability to quantify CNV areas, rats were given either triamcinolone acetonide or dexamethasone sodium phosphate to treat CNV and compared to untreated rats. The rat CNV lesion areas measured from 5-week histology sections from each treatment group were compared to areas measured from the corresponding FA images. MOT was able to detect statistical decreases in rodent CNV area in the treatment groups versus control from weeks 3 through 5. The ratio of CNV area measured from histology to area measured from FA images was not statistically different between groups. Finally, to determine the usefulness of MOT on pathological morphologies of CNV, MOT was performed on late-phase FA images from patients with classic and diffuse CNV. The technique was able to segment classical CNV in wAMD patients, but performed poorly with diffuse CNV. MOT provides a robust, objective, and quantifiable area measurement of CNV lesion area in both experimentally-induced and pathological CNV. The results indicate that MOT could be a useful research tool in helping evaluate the effects of therapeutics on CNV growth. PMID:24316422

  3. Coronary Angiography Safety between Transradial and Transfemoral Access

    PubMed Central

    Mishra, Vikas; Afdaali, Nasar; Jha, Mukesh Jitendra; Kumar, Ashutosh; Asif, Mohammad; Thakur, Ramesh; Varma, Chandra Mohan

    2016-01-01

    Background and Aim. The aim of study was to evaluate safety, feasibility, and procedural variables of transradial approach compared with transfemoral approach in a standard population of patients undergoing coronary catheterization as one of the major criticisms of the transradial approach is that it takes longer overall procedure and fluoroscopy time, thereby causing more radiation exposure. Method. Between January 2015 and December 2015, a total of 1,997 patients in LPS Institute of Cardiology, GSVM Medical College, Kanpur, UP, India, undergoing coronary catheterization were randomly assigned to the transradial or transfemoral approach. Result. Successful catheterization was achieved in 1045 of 1076 patients (97.1%) in the transradial group and in 918 of 921 patients (99.7%) in the transfemoral group (p = 0.001). Comparing the transradial and transfemoral approaches, fluoroscopy time (2.46 ± 1.22 versus 2.83 ± 1.31 min; p = 0.32), procedure time (8.89 ± 2.72 versus 9.33 ± 2.82 min; p = 0.56), contrast volume (67.52 ± 22.54 versus 71.63 ± 25.41 mL; p = 0.32), radiation dose as dose area product (24.2 ± 4.21 versus 22.3 ± 3.46 Gycm2; p = 0.43), and postprocedural rise of serum creatinine (6 ± 4.5% versus 8 ± 2.6%; p = 0.41) were not significantly different while vascular access site complications were significantly lower in transradial group than transfemoral group (3.9% versus 7.6%; p = 0.04). Conclusion. The present study shows that transradial access for coronary angiography is safe among patients compared to transfemoral access with lower rate of local vascular complications. PMID:27885351

  4. Optical Coherence Tomography Angiography Findings in Stargardt Disease

    PubMed Central

    Borrelli, Enrico; Di Antonio, Luca; Mattei, Peter A.; Senatore, Alfonso; Di Nicola, Marta; Mariotti, Cesare

    2017-01-01

    Background to assess vessel density of superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) in advanced Stargardt disease (STGD) using optical coherence tomography angiography (OCTA) and correlate these findings with macular function using pattern electroretinogram (PERG) and multifocal electroretinogram (mfERG). Methods Twelve patients (24 eyes) with advanced STGD underwent vessel densities and macular thickness measurements using OCTA. A control group of 24 healthy controls (24 eyes) was chosen for comparison. In the STGD group correlation between vessel density and macular thickness and between macular function and morphologic parameters were evaluated. Results Whole parafoveal vessel density (VD) of SCP was significantly lower in STGD group compared to the control group (p<0.05). Foveal VD and whole parafoveal VD of the DCP were significantly lower in STGD group compared to the controls (p<0.05). CC was significantly decreased in STGD compared to controls (p<0.05). Foveal macular thickness (MT), full parafoveal MT, and inner limiting membrane (ILM)-inner plexiform layer (IPL) parafoveal MT thickness were decreased in STGD eyes compared to controls (p<0.001). PERG and mfERG were both significantly reduced in STGD compared to controls (p<0.001). A direct correlation was found between full parafoveal MT and vessel density in the STGD group. Conclusions Patients with advanced STGD showed a reduction of SCP, DCP and CC compared to healthy eyes related to a reduction of total and ILM-IPL macular thickness. These results suggest that both retinal capillaris plexuses and choriocapillaris reduction occur in STDG along with inner and outer retinal thinning. PMID:28151966

  5. Filtered region of interest cone-beam rotational angiography

    SciTech Connect

    Schafer, Sebastian; Noeel, Peter B.; Walczak, Alan M.; Hoffmann, Kenneth R.

    2010-02-15

    Purpose: Cone-beam rotational angiography (CBRA) is widely used in the modern clinical settings. In a number of procedures, the area of interest is often considerably smaller than the field of view (FOV) of the detector, subjecting the patient to potentially unnecessary x-ray dose. The authors therefore propose a filter-based method to reduce the dose in the regions of low interest, while supplying high image quality in the region of interest (ROI). Methods: For such procedures, the authors propose a method of filtered region of interest (FROI)-CBRA. In the authors' approach, a gadolinium filter with a circular central opening is placed into the x-ray beam during image acquisition. The central region is imaged with high contrast, while peripheral regions are subjected to a substantial lower intensity and dose through beam filtering. The resulting images contain a high contrast/intensity ROI, as well as a low contrast/intensity peripheral region, and a transition region in between. To equalize the two regions' intensities, the first projection of the acquisition is performed with and without the filter in place. The equalization relationship, based on Beer's law, is established through linear regression using corresponding filtered and nonfiltered data. The transition region is equalized based on radial profiles. Results: Evaluations in 2D and 3D show no visible difference between conventional FROI-CBRA projection images and reconstructions in the ROI. CNR evaluations show similar image quality in the ROI, with a reduced CNR in the reconstructed peripheral region. In all filtered projection images, the scatter fraction inside the ROI was reduced. Theoretical and experimental dose evaluations show a considerable dose reduction; using a ROI half the original FOV reduces the dose by 60% for the filter thickness of 1.29 mm. Conclusions: These results indicate the potential of FROI-CBRA to reduce the dose to the patient while supplying the physician with the desired

  6. Vertebrobasilar system computed tomographic angiography in central vertigo

    PubMed Central

    Paşaoğlu, Lale

    2017-01-01

    Abstract The incidence of vertigo in the population is 20% to 30% and one-fourth of the cases are related to central causes. The aim of this study was to evaluate computed tomography angiography (CTA) findings of the vertebrobasilar system in central vertigo without stroke. CTA and magnetic resonance images of patients with vertigo were retrospectively evaluated. One hundred twenty-nine patients suspected of having central vertigo according to history, physical examination, and otological and neurological tests without signs of infarction on diffusion-weighted magnetic resonance imaging were included in the study. The control group included 120 patients with similar vascular disease risk factors but without vertigo. Vertebral and basilar artery diameters, hypoplasias, exit-site variations of vertebral artery, vertebrobasilar tortuosity, and stenosis of ≥50% detected on CTA were recorded for all patients. Independent-samples t test was used in variables with normal distribution, and Mann–Whitney U test in non-normal distribution. The difference of categorical variable distribution according to groups was analyzed with χ2 and/or Fisher exact test. Vertebral artery hypoplasia and ≥50% stenosis were seen more often in the vertigo group (P = 0.000, <0.001). Overall 78 (60.5%) vertigo patients had ≥50% stenosis, 54 (69.2%) had stenosis at V1 segment, 9 (11.5%) at V2 segment, 2 (2.5%) at V3 segment, and 13 (16.6%) at V4 segment. Both vertigo and control groups had similar basilar artery hypoplasia and ≥50% stenosis rates (P = 0.800, >0.05). CTA may be helpful to clarify the association between abnormal CTA findings of vertebral arteries and central vertigo. This article reveals the opportunity to diagnose posterior circulation abnormalities causing central vertigo with a feasible method such as CTA. PMID:28328808

  7. Medical personnel and patient dosimetry during coronary angiography and intervention

    NASA Astrophysics Data System (ADS)

    Efstathopoulos, Efstathios P.; Makrygiannis, Stamatis S.; Kottou, Sofia; Karvouni, Evangelia; Giazitzoglou, Eleftherios; Korovesis, Socrates; Tzanalaridou, Efthalia; Raptou, Panagiota D.; Katritsis, Demosthenes G.

    2003-09-01

    Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the contribution of each projection to kerma-area product (KAP) and irradiation time, (4) comparing results with established DRL values in this clinical setting and (5) estimating the risk for fatal cancer to patients and operators. Measurements were performed during 40 consecutive procedures of coronary angiography (CA), half of which were followed by ad hoc coronary angioplasty (PTCA). KAP measurements were used for patients and thermoluminescent dosimetry for the in-room personnel. The mean KAP value per procedure for CA was 29 +/- 9 Gy cm2. Thirty four per cent of KAP was due to fluoroscopy, whereas the remainder (66%) was due to digital cine. Accordingly, the mean KAP value per PTCA procedure was 75 +/- 30 Gy cm2, and contribution of fluoroscopy is 57%. Effective dose per year was estimated to be 0.04-0.05 mSv y-1 for the primary operator, and 0.03-0.04 mSv y-1 for those assisting. Corresponding measurements for radiographer and nurse were below detectable level, implying minimal radiation hazards for them. Regarding radiation exposure, coronary intervention is considered a quite safe procedure for both patients and personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered. Exposure optimization though should be constantly sought through continuous review of procedures.

  8. Periodontal and coronary heart disease in patients undergoing coronary angiography.

    PubMed

    Berent, Robert; Auer, Johann; Schmid, Peter; Krennmair, Gerald; Crouse, Stephen F; Green, John S; Sinzinger, Helmut; von Duvillard, Serge P

    2011-01-01

    Periodontal inflammation has been implicated in atherosclerosis and coronary heart disease (CHD). Coronary angiography (CA) is used in the assessment of CHD; only a few studies have evaluated periodontal disease (PD) and angiographic measures of coronary atherosclerosis. The aim of this study was to investigate the association between CHD and PD. In this prospective epidemiologic study, 466 patients underwent CA and were assessed for PD. All patients underwent physical, laboratory, cardiac, and dental examination including dental x-rays. Periodontal disease and coronary angiograms were evaluated blindly by a dentist and 2 cardiologists, respectively. A coronary stenosis greater than 50% was ruled as CHD. Periodontal disease was defined and measured with the Community Periodontal Index of Treatment Needs (CPITN); and if at least 2 sextants (segments dividing mandible and maxilla into 6) were recorded as having CPITN of at least 3 (signifying that sextant had periodontal pocket depth ≥ 3.5 mm), the patient was coded as having PD. Three-hundred forty-nine patients (74.9%) had CHD assessed by CA The CHD patients had PD in 55.6% vs 41.9% in the non-CHD patients (P < .01). The CPITN scores were significantly higher in patients with vs without CHD, 2.43 vs 2.16, respectively (P = .023). After adjusting for age, sex, and risk factors for atherosclerosis with additional inclusion of C-reactive protein and erythrocyte sedimentation rate, PD remained significantly related to CHD (odds ratio = 1.9; 95% confidence interval, 1.2-3.1). Other predictors for CHD were male sex, age, high-density lipoprotein cholesterol, and diabetes. Our results demonstrate an increased odds ratio for angiographically determined CHD in patients with PD and that CHD and PD may cluster in particular groups of a population. Our data indicate that PD represents a potentially modifiable risk factor that is both preventable and treatable with predictable treatments that pose negligible risk.

  9. Accuracy of dual-source CT to identify significant coronary artery disease in patients with uncontrolled hypertension presenting with chest pain: comparison with coronary angiography.

    PubMed

    Marwan, Mohamed; Pflederer, Tobias; Schepis, Tiziano; Seltmann, Martin; Klinghammer, Lutz; Muschiol, Gerd; Ropers, Dieter; Daniel, Werner G; Achenbach, Stephan

    2012-06-01

    It has been previously reported that the sensitivity and specificity of multislice CT for detecting significant CAD (coronary artery disease) is high. Chest pain is a common presentation in patients with uncontrolled hypertension. We investigated the sensitivity and specificity of dual-source CT to detect and rule out significant CAD in patients presenting with uncontrolled hypertension accompanied by chest pain. 260 consecutive patients presenting with acute chest pain in the context of stage 2 hypertension (systolic pressure ≥160 and/or diastolic pressure ≥100) were enrolled in the study. After admission, control of blood pressure and risk stratification, 82 patients were excluded due to renal insufficiency, prior coronary revascularisation or refused participation in the study. 90 further patients with low pre-test probability of CAD were also excluded. 88 remaining patients were subjected to CT coronary angiography using dual-source CT (Definition, Siemens Medical Solutions, Forchheim, Germany) within 24 h before invasive coronary angiography. A contrast-enhanced volume dataset was acquired (120 kV, 400 mAs/rot, collimation 2 × 64 × 0.6 mm, retrospective ECG gating). Data sets were evaluated concerning the presence or absence of significant coronary stenoses and validated against invasive coronary angiography. A significant stenosis was assumed if the diameter reduction was ≥50%. 88 patients (mean age 66 ± 11 years, mean heart rate 61 ± 9 bpm) were evaluated regarding the presence or absence of significant CAD (at least one stenosis ≥50% diameter reduction). Mean systolic blood pressure on presentation was 203 ± 20 mmHg and mean diastolic blood pressure was 103 ± 13 mmHg. On a per patient basis, the sensitivity and specificity for dual-source CT to detect significant CAD in vessels >1.5 mm diameter was 100% (36/36, 95% CI 90-100) and 90% (47/52, 95% CI 79-97), respectively with a negative predictive value (NPV) of 100% (47/47, 95% CI 92-100) and a

  10. Development of a renal subcapsular hematoma during angiography for diagnosis and subsequent treatment of hepatocellular carcinoma.

    PubMed

    Hirao, Akihiro; Tomonari, Testu; Tanaka, Hironori; Tanaka, Kumiko; Kagawa, Miwako; Tanaka, Takahiro; Taniguchi, Tatsuya; Harada, Rie; Sato, Momoko; Muguruma, Naoki; Takayama, Tetsuji

    2014-04-01

    A renal subcapsular hematoma rarely occurs without a history of trauma. It has been reported as a complication of urological interventions and also reported to occur spontaneously in patients with renal malignancies. However, there are no previous reports of renal subcapsular hematomas occurring in connection with abdominal angiography. We report here a case of a renal subcapsular hematoma that developed and was recognized during abdominal angiography for treatment of hepatocellular carcinoma (HCC). An 80-year-old male was referred to our hospital for transarterial embolization for multiple HCCs. His past medical history included hypertension. His laboratory data showed slightly decreased number of platelets and hepaplastin test due to liver cirrhosis. When computed tomography angiography was performed, a 7-cm subcapsular hematoma developed and was recognized over the right kidney during the procedure. He was successfully managed supportively with blood transfusion, tranexamic acid and antibiotics. Since thrombocytopenia and hypertension are reportedly risk factors for hematoma formation, careful manipulation is required during angiography in HCC patients with liver cirrhosis and hypertension. It must be kept in mind that rare complications, such as a renal subcapsular hematoma, can happen during abdominal angiography for diagnostic and interventional treatment of HCC.

  11. Reconstruction of coronary arteries from X-ray angiography: A review.

    PubMed

    Çimen, Serkan; Gooya, Ali; Grass, Michael; Frangi, Alejandro F

    2016-08-01

    Despite continuous progress in X-ray angiography systems, X-ray coronary angiography is fundamentally limited by its 2D representation of moving coronary arterial trees, which can negatively impact assessment of coronary artery disease and guidance of percutaneous coronary intervention. To provide clinicians with 3D/3D+time information of coronary arteries, methods computing reconstructions of coronary arteries from X-ray angiography are required. Because of several aspects (e.g. cardiac and respiratory motion, type of X-ray system), reconstruction from X-ray coronary angiography has led to vast amount of research and it still remains as a challenging and dynamic research area. In this paper, we review the state-of-the-art approaches on reconstruction of high-contrast coronary arteries from X-ray angiography. We mainly focus on the theoretical features in model-based (modelling) and tomographic reconstruction of coronary arteries, and discuss the evaluation strategies. We also discuss the potential role of reconstructions in clinical decision making and interventional guidance, and highlight areas for future research.

  12. Simulator-Based Angiography and Endovascular Neurosurgery Curriculum: A Longitudinal Evaluation of Performance Following Simulator-Based Angiography Training

    PubMed Central

    Pannell, J. Scott; Wali, Arvin R; Hirshman, Brian R; Steinberg, Jeffrey A; Cheung, Vincent J; Oveisi, David; Hallstrom, Jon; Khalessi, Alexander A

    2016-01-01

    This study establishes performance metrics for angiography and neuroendovascular surgery procedures based on longitudinal improvement in individual trainees with differing levels of training and experience. Over the course of 30 days, five trainees performed 10 diagnostic angiograms, coiled 10 carotid terminus aneurysms in the setting of subarachnoid hemorrhage, and performed 10 left middle cerebral artery embolectomies on a Simbionix Angio Mentor™ simulator. All procedures were nonconsecutive. Total procedure time, fluoroscopy time, contrast dose, heart rate, blood pressures, medications administered, packing densities, the number of coils used, and the number of stent-retriever passes were recorded. Image quality was rated, and the absolute value of technically unsafe events was recorded. The trainees’ device selection, macrovascular access, microvascular access, clinical management, and the overall performance of the trainee was rated during each procedure based on a traditional Likert scale score of 1=fail, 2=poor, 3=satisfactory, 4=good, and 5=excellent. These ordinal values correspond with published assessment scales on surgical technique. After performing five diagnostic angiograms and five embolectomies, all participants demonstrated marked decreases in procedure time, fluoroscopy doses, contrast doses, and adverse technical events; marked improvements in image quality, device selection, access scores, and overall technical performance were additionally observed (p < 0.05). Similarly, trainees demonstrated marked improvement in technical performance and clinical management after five coiling procedures (p < 0.05). However, trainees with less prior experience deploying coils continued to experience intra-procedural ruptures up to the eighth embolization procedure; this observation likely corresponded with less tactile procedural experience to an exertion of greater force than appropriate for coil placement. Trainees across all levels of training and

  13. Non-invasive assessment of bleeding pulmonary artery aneurysms due to Behçet disease.

    PubMed

    Greene, R M; Saleh, A; Taylor, A K; Callaghan, M; Addis, B J; Nzewi, O C; van Zyl, W V

    1998-01-01

    Because of its ability to depict intravascular, intramural, and extramural pathology, non-invasive imaging is well suited to assessing life-threatening hemoptysis that may complicate Behçet disease. We made exclusive use of CT angiography supplemented by MR to identify pulmonary thromboembolism, mediastinal lymphadenopathy, and bilateral pulmonary artery aneurysms with signs of previous unilateral rupture. Two-dimensional reformatted CT images provided surgeons with a road map of upstream and downstream vascular relationships prior to aneurysm resection. Imaging findings were confirmed by surgery and pathology. Non-invasive imaging proved to be a useful alternative to standard catheter arteriography in the preoperative assessment of hemoptysis in this patient with Behçet disease.

  14. Giant invasive prolactinomas

    SciTech Connect

    Murphy, F.Y.; Vesely, D.L.; Jordan, R.M.; Flanigan, S.; Kohler, P.O.

    1987-11-01

    Two of the largest prolactinomas ever documented that have been followed for nine and 10 years, respectively, demonstrate how aggressive prolactinomas may become and how difficult invasive prolactinomas are to treat. One of these prolactinomas invaded both internal auditory canals and simultaneously grew inferiorly, reducing the bony support of the skull and necessitating the patient to utilize both hands to hold his head up. The second patient's prolactinoma invaded the sphenoidal, ethmoidal, and cavernous sinuses. Both of these patients had neurosurgical debulking of their tumors followed by radiation therapy. Neither patient's prolactin levels decreased significantly during their first five years post-surgically, at which time bromocriptine was added. Since then, there has been a gradual lowering of serum prolactin levels and a decrease in the size of these tumors. These cases demonstrate that prolonged treatment and very large doses of bromocriptine may be necessary for tumor reduction in patients with invasive prolactinomas.

  15. Biogeography of Mediterranean Invasions

    NASA Astrophysics Data System (ADS)

    Groves, R. H.; di Castri, F.

    The Mediterranean basin, California, Chile, the western Cape of South Africa, and southern Australia share a Mediterranean climate characterized by cool, wet winters and hot, dry summers. These five regions have differing patterns of human settlement, but similarities in natural vegetation and some faunal assemblages. These likenesses are enhanced with time by an increasing level of biotic exchange among the regions. An initiative of a subcommittee of SCOPE (Scientific Committee on Problems of the Environment), which realized that the integrity of many natural ecosystems is being threatened by the ingress of invasive species, this book uniquely documents the introduced floras and faunas, especially plants, buds, and mammals, in these five regions of Mediterranean climate, and aims to increase our understanding of the ecology of biological invasions. In doing so, it points a way to more effectively manage the biota of these regions.

  16. Non-invasive diagnosis of mitral regurgitation by Doppler echocardiography.

    PubMed Central

    Blanchard, D; Diebold, B; Peronneau, P; Foult, J M; Nee, M; Guermonprez, J L; Maurice, P

    1981-01-01

    The value of Doppler echocardiography for the non-invasive diagnosis of mitral regurgitation was studied blindly in 161 consecutive invasively investigated adult patients. Regurgitation was graded from 0 to 3 at selective left ventricular angiography. The Doppler echocardiographic examination was considered to be positive when a disturbed systolic flow was found within the left atrium behind the aorta or the anterior leaflet of the mitral valve. The test was considered to be negative in the absence of a regurgitant jet. The level of the signal to noise ratio was checked by the recording of the ventricular filling flow. The study was performed in 131 cases from the left side of the sternum and in 101 cases from the apex. There were no false positives and thus the specificity was 100 per cent. The 20 false negatives were all in patients with grade 1 regurgitation. Thus only some (33%) instances of mild regurgitation were misdiagnosed, and the sensitivity for moderate to severe mitral regurgitation was 100 per cent. PMID:7236465

  17. [Emerging invasive fungal infections].

    PubMed

    Alvez, F; Figueras, C; Roselló, E

    2010-07-01

    The frequency and diversity of invasive fungal infections has changed over the last 25 years. The emergence of less common, but medically important fungi has increased, and the children at risk has expanded, with the inclusion of medical conditions such as cancer, mainly haematological malignancy or stem cell transplant, immunosuppressive therapy, prolonged neutropenia, and T-cell immunodeficiency. Among mould infections, fusariosis and phaeohyphomycosis (Dematiaceous fungi) have been increasingly reported in this group of patients. To successfully manage these challenging infections, it is imperative that paediatricians and sub-specialists remain aware of the optimal and timely diagnosis and therapeutic options. Unlike other common mycoses that cause human disease, there no simple antigen or serological tests available to detect these pathogens in tissue or blood. The outcome for these disseminate, and often refractory fungal infections in neutropenic patients and transplant recipients remains extremely poor, requiring early and aggressive therapy. Unfortunately there are no guidelines outlining the choices for optimal therapy in the treatment of paediatric invasive fungal infections do not exist, and on the other hand are limited paediatric data available comparing antifungal agents in children with proven, probable or suspected invasive fungal infection. The options for treatment rest mainly on some adult guidelines that comment on the treatment of these emerging and uncommon important fungi in children. Despite the sparse clinical trials available on treatment and its poor outcome, options for treatment of invasive fungal infections have increased with the advance of new antifungal agents, with improved tolerability and increased range of activity. The epidemiology, clinical manifestations, diagnosis and treatment of fusariosis and phaeohyphomycosis are discussed in this article.

  18. Critical Hand Ischemia After Radial Access for Coronary Angiography – Case Report

    PubMed Central

    Bojakowski, Krzysztof; Zawadzki, Michał; Mruk, Bartosz; Andziak, Piotr; Walecki, Jerzy

    2017-01-01

    Summary Background Radial artery is now the most frequent access for coronary angiography and intervention. Despite the common opinion that it is safer than femoral access, it has the potential for serious complications. One of them is upper limb ischemia caused by radial artery thrombosis. Case Report We are presenting a case of critical hand ischemia after coronary angiography performed through radial access despite existing risk factors, which may be considered as relative contraindications. Conclusions In the presented case, decision was made to use radial access despite several risk factors of upper limb ischemia – diabetes, end-stage renal failure, hyperparathyroidism, or even symptoms of left upper limb ischemia. Furthermore, for diagnostic coronary angiography 5F instead of 4F introducer was used. PMID:28144386

  19. Computed tomography angiography: state-of-the-art imaging using multidetector-row technology.

    PubMed

    Napoli, Alessandro; Fleischmann, Dominik; Chan, Frandics P; Catalano, Carlo; Hellinger, Jeffrey C; Passariello, Roberto; Rubin, Geoffrey D

    2004-01-01

    Multidetector-row computed tomography (MDCT) is an essential diagnostic modality for many clinical algorithms. This is particularly true with regard to the evaluation of cardiovascular disease. As a result of increased image acquisition speed, improved spatial resolution, and greater scan volume, MDCT angiography (computed tomography angiography [CTA]) has become an excellent noninvasive imaging technique, replacing intra-arterial digital subtraction angiography for most vascular territories. The clinical success of CTA depends on precise synchronization of image acquisition with optimal vascular enhancement. As technology continuously evolves, however, this task can be challenging. It remains important to have a fundamental knowledge of the principles behind technical parameters and contrast medium administration. This article reviews these essential principles, followed by an overview of current clinical applications.

  20. Comparison of Angiography and Intravascular Ultrasound Before and After Balloon Angioplasty of the Femoropopliteal Artery

    SciTech Connect

    Lankeren, Winnifred van; Gussenhoven, Elma J.; Pieterman, Herman; Sambeek, Marc R.H.M. van; Lugt, Aad van der

    1998-09-15

    Purpose: To compare angiographic and intravascular ultrasound (IVUS) data before and after balloon angioplasty (PTA) of the femoropopliteal artery. Methods: Qualitative and quantitative analyses were performed on corresponding angiographic and IVUS levels obtained from 135 patients. Results: IVUS detected more lesions, calcified lesions, and vascular damage than angiography. Sensitivity of angiography was good for the presence of a lesion (84%), moderate for eccentric lesions (53%) and for vascular damage (52%), and poor for calcified lesions (30%). The increase in angiographic diameter stenosis was associated with a decrease in lumen area and increase in percentage area stenosis on IVUS. Conclusions: Angiography is less sensitive than IVUS for detecting lesion eccentricity, calcified lesions, and vascular damage. Presence of a lesion and amount of plaque were underestimated angiographically. Only before PTA was good agreement found between angiographic diameter stenosis and lumen size on IVUS.

  1. RetCam II Fluorescein Angiography to Guide Treatment and Diagnosis of Coats Disease.

    PubMed

    Koozekanani, Dara D; Connor, Thomas B; Wirostko, William J

    2010-03-09

    Coats disease is a well-described clinical condition featuring peripheral leakage from telangiectatic vasculature, resulting in exudative retinal detachments and exudative deposits. It often affects pediatric patients, requiring examinations and treatments to be performed under anesthesia. It can be difficult to distinguish from retinoblastoma. The RetCam II is a wide-field fundus imaging system that can also obtain intraoperative fluorescein angiography. The case of a 5-year-old girl diagnosed with Coats disease is presented. She presented with an exudative detachment, a submacular nodule, and peripheral telangiectasis. An examination under anesthesia, including angiography, was performed. The angiograph revealed characteristic aneurysms as well as extensive areas of telangiectasis and ischemia not readily visible on examination. The angiogram allowed more diagnostic certainty and guided a more complete treatment than otherwise possible. We propose that fluorescein angiography with the RetCam II system can be a useful tool when examining and treating pediatric patients with Coats disease.

  2. Renal trauma: radiological studies - comparison of urography, computed tomography, angiography, and radionuclide studies

    SciTech Connect

    Lang, E.K.; Sullivan, J.; Frentz, G.

    1985-01-01

    Excretory urography, computed radionuclide urography, angiography, and both conventional and dynamic computed tomography (CT) were compared with regard to accuracy, sensitivity, and specificity in 388 patients with renal trauma. Used as the triage examination, urography established the absence of significant renal injury with an accuracy of 87%, obviating further evaluation. Dynamic CT proved to be the best methods of assessing parenchymal injuries, establishing the correct diagnosis in 129 out of 130 cases compared to 116/130 for conventional CT. Angiography was the procedure of choice for diagnosis and categorization of renal artery injuries, which were diagnosed correctly in all 43 cases. The choice between dynamic CT and angiography as the second examination rests upon careful evaluation of clinical and urographic findings for signs of renal artery injury which would mandate angiographic assessment.

  3. Fusiform Lenticulostriate Artery Aneurysm with Subarachnoid Hemorrhage: The Role for Superselective Angiography in Treatment Planning

    PubMed Central

    Kochar, P.S.; Morrish, W.F.; Hudon, M.E.; Wong, J.H.; Goyal, M.

    2010-01-01

    Summary Aneurysms of the lenticulostriatal perforating arteries are rare and either involve the middle cerebral artery-perforator junction or are located distally in basal ganglia. We describe a rare ruptured fusiform lenticulostriatal perforating artery aneurysm arising from a proximal M2 MCA branch, discerned on superselective microcatheter angiography, presenting solely with subarachnoid hemorrhage (SAH). A 50-year-old previously healthy man presented with diffuse SAH and negative CT angiogram. Cerebral angiogram demonstrated a 2 mm fusiform aneurysm presumably arising from the right lateral lenticulostriate perforator but the exact origin of the perforator was unclear. Superselective angiography was required to precisely delineate the aneurysm and its vessel of origin and directly influenced treatment planning (surgical trapping). Superselective microcatheter angiography provides both an option for endovascular therapy as well as more accurate delineation for surgical planning for these rare aneurysms. PMID:20977857

  4. [Patients with hemodynamic unstable pelvic fractures in extremis: pelvic packing or angiography?].

    PubMed

    Liñán-Padilla, A; Giráldez-Sánchez, M Á; Serrano-Toledano, D; Lázaro-Gonzálvez, A; Cano-Luís, P

    2013-01-01

    The multidisciplinary management of patients with pelvic trauma has improved prognosis, but mortality is still very high. The appropriate treatment strategy remains controversial, especially regarding the control of bleeding in patients whose clinical situation is extreme by using angiography or pelvic packing. We propose using a tool of evidence-based medicine (CAT) the benefit of the completion of pelvic packing in relation to a specific clinical question from a specific situation. What is best for the management of bleeding, extraperitoneal pelvic packing or angiography, in patients with hemodynamically unstable pelvic fracture in extremis? From this study we can conclude that angiography may improve control of bleeding in patients with arterial bleeding and hemodynamically stable but the packing has priority in patients with pelvic fractures and hemodynamic instability.

  5. Design study of Thomson Laser-Electron X-ray Generator (LEX) for Millisecond Angiography

    NASA Astrophysics Data System (ADS)

    Artyukov, I. A.; Bessonov, E. G.; Feshchenko, R. M.; Gorbunkov, M. V.; Maslova, Yu Ya; Popov, N. L.; Dyachkov, N. V.; Postnov, A. A.; Vinogradov, S. L.; Vinogradov, A. V.

    2017-01-01

    In this concept study a laser-electron X-ray generator (LEX) is considered for the medical imaging of the inner vessel structure. It is demonstrated that the modern lasers and linear electron accelerators are suitable for the design of the new generation of angiography medical equipment combining higher spatial and time resolution with the reduced patient dose. Angiography setup based on LEXG can make use of different contrast media (iodine, gadolinium) working on absorption edge due to the narrow tuneable spectrum which is not possible with conventional X-ray tubes. In the present study all estimations are made for iodine-based contrast agents. The conclusion is that modern technologies allow practical implementation of LEX for angiography based on multibunch linear accelerator and photon storage device.

  6. Comparison of CT and angiography in assessing resectability of pancreatic carcinoma

    SciTech Connect

    Jafri, S.Z.H.; Aisen, A.M.; Glazer, G.M.; Weiss, C.A.

    1984-03-01

    A retrospective study of 27 patients with pancreatic carcinoma compared computed tomography (CT) and angiography in their ability to predict resectability of the neoplasm, using encasement of the splanchnic vessels as the criterion for nonresectability. Five patients had resectable tumor at surgery; the other 22 had unresectable disease. Tumor involvement of the splanchnic vessels was determined in 18 patients by CT examination and in 19 patients by angiography. Several other patients were found to have liver metastases, resulting in a radiologic diagnosis of nonresectability in 20 patients overall. All patients considered to have unresectable disease on the basis of either radiologic method proved to have unresectable tumor at surgery. CT is about as accurate as angiography in assessing resectability of pancreatic carcinoma.

  7. [Minimally invasive thymus surgery].

    PubMed

    Rückert, J C; Ismail, M; Swierzy, M; Braumann, C; Badakhshi, H; Rogalla, P; Meisel, A; Rückert, R I; Müller, J M

    2008-01-01

    There are absolute and relative indications for complete removal of the thymus gland. In the complex therapy of autoimmune-related myasthenia gravis, thymectomy plays a central role and is performed with relative indication. In case of thymoma with or without myasthenia, thymectomy is absolutely indicated. Thymus resection is further necessary for cases of hyperparathyroidism with ectopic intrathymic parathyroids or with certain forms of multiple endocrine neoplasia. The transcervical operation technique traditionally reflected the well-founded desire for minimal invasiveness for thymectomy. Due to the requirement of radicality however, most of these operations were performed using sternotomy. With the evolution of therapeutic thoracoscopy in thoracic surgery, several pure or extended minimally invasive operation techniques for thymectomy have been developed. At present uni- or bilateral, subxiphoid, and modified transcervical single or combination thoracoscopic techniques are in use. Recently a very precise new level of thoracoscopic operation technique was developed using robotic-assisted surgery. There are special advantages of this technique for thymectomy. An overview of the development and experiences with minimally invasive thymectomy is presented, including data from the largest series published so far.

  8. In Vivo Angiography Quantifies Oxygen-Induced Retinopathy Vascular Recovery

    PubMed Central

    Mezu-Ndubuisi, Olachi J.

    2016-01-01

    ABSTRACT Purpose Retinopathy of prematurity (ROP) is a potentially blinding vasoproliferative disease. There is no standardized way to quantify plus disease (tortuous and dilated retinal vessels) or characterize abnormal recovery during ROP monitoring. This study objectively studies vascular features in live mice during development using noninvasive retinal imaging. Methods Using fluorescein angiography (FA), retinal vascular features were quantified in live mice with oxygen induced retinopathy (OIR). A total of 105 wild-type mice were exposed to 77% oxygen from postnatal day 7 (P7) till P12 (OIR mice). Also, 105 age-matched pups were raised in room air (RA mice). In vivo FA was performed at early (P16 to P20), mid (P23 to P27), late (P30 to P34), and mature (P47) phases of retinal vascular development. Retinal vascular area, retinal vein width, and retinal artery tortuosity were quantified. Results Retinal artery tortuosity was higher in OIR than RA mice at early (p < 0.0001), mid (p < 0.0001), late (p < 0.0001), and mature (p < 0.0001) phases. Retinal vascular area in OIR mice increased from early to mid-phase (p < 0.0001), but remained unchanged from mid to late (p = 0.23), and from late to mature phase (p = 0.98). Retinal vein width was larger in OIR mice compared to RA mice during early phase only. Arteries in OIR mice were more tortuous from early to mid-phase (p < 0.0001), but tortuosity remained stable from mid through mature phase. RA mice had an increase in retinal vascular area from early to late phase, but maintained uniform retinal vein width and retinal artery tortuosity in all phases. Conclusions In vivo FA distinguished arterial and venous features, similar to plus disease, and revealed aberrant recovery of OIR mice (arterial tortuosity, reduced capillary density, and absent neovascular buds) that persisted into adulthood. Retinal artery tortuosity may be a reliable, objective marker of severity of ROP. Infants with abnormal retinal vascular

  9. 4D motion animation of coronary arteries from rotational angiography

    NASA Astrophysics Data System (ADS)

    Holub, Wolfgang; Rohkohl, Christopher; Schuldhaus, Dominik; Prümmer, Marcus; Lauritsch, Günter; Hornegger, Joachim

    2011-03-01

    Time-resolved 3-D imaging of the heart is a major research topic in the medical imaging community. Recent advances in the interventional cardiac 3-D imaging from rotational angiography (C-arm CT) are now also making 4-D imaging feasible during procedures in the catheter laboratory. State-of-the-art reconstruction algorithms try to estimate the cardiac motion and utilize the motion field to enhance the reconstruction of a stable cardiac phase (diastole). The available data offers a handful of opportunities during interventional procedures, e.g. the ECG-synchronized dynamic roadmapping or the computation and analysis of functional parameters. In this paper we will demonstrate that the motion vector field (MVF) that is output by motion compensated image reconstruction algorithms is in general not directly usable for animation and motion analysis. Dependent on the algorithm different defects are investigated. A primary issue is that the MVF needs to be inverted, i.e. the wrong direction of motion is provided. A second major issue is the non-periodicity of cardiac motion. In algorithms which compute a non-periodic motion field from a single rotation the in depth motion information along viewing direction is missing, since this cannot be measured in the projections. As a result, while the MVF improves reconstruction quality, it is insufficient for motion animation and analysis. We propose an algorithm to solve both problems, i.e. inversion and missing in-depth information in a unified framework. A periodic version of the MVF is approximated. The task is formulated as a linear optimization problem where a parametric smooth motion model based on B-splines is estimated from the MVF. It is shown that the problem can be solved using a sparse QR factorization within a clinical feasible time of less than one minute. In a phantom experiment using the publicly available CAVAREV platform, the average quality of a non-periodic animation could be increased by 39% by applying the

  10. Intracranial CT angiography obtained from a cerebral CT perfusion examination

    SciTech Connect

    Gratama van Andel, H. A. F.; Venema, H. W.; Majoie, C. B.; Den Heeten, G. J.; Grimbergen, C. A.; Streekstra, G. J.

    2009-04-15

    CT perfusion (CTP) examinations of the brain are performed increasingly for the evaluation of cerebral blood flow in patients with stroke and vasospasm after subarachnoid hemorrhage. Of the same patient often also a CT angiography (CTA) examination is performed. This study investigates the possibility to obtain CTA images from the CTP examination, thereby possibly obviating the CTA examination. This would save the patient exposure to radiation, contrast, and time. Each CTP frame is a CTA image with a varying amount of contrast enhancement and with high noise. To improve the contrast-to-noise ratio (CNR) we combined all 3D images into one 3D image after registration to correct for patient motion between time frames. Image combination consists of weighted averaging in which the weighting factor of each frame is proportional to the arterial contrast. It can be shown that the arterial CNR is maximized in this procedure. An additional advantage of the use of the time series of CTP images is that automatic differentiation between arteries and veins is possible. This feature was used to mask veins in the resulting 3D images to enhance visibility of arteries in maximum intensity projection (MIP) images. With a Philips Brilliance 64 CT scanner (64x0.625 mm) CTP examinations of eight patients were performed on 80 mm of brain using the toggling table technique. The CTP examination consisted of a time series of 15 3D images (2x64x0.625 mm; 80 kV; 150 mAs each) with an interval of 4 s. The authors measured the CNR in images obtained with weighted averaging, images obtained with plain averaging, and images with maximal arterial enhancement. The authors also compared CNR and quality of the images with that of regular CTA examinations and examined the effectiveness of automatic vein masking in MIP images. The CNR of the weighted averaged images is, on the average, 1.73 times the CNR of an image at maximal arterial enhancement in the CTP series, where the use of plain averaging

  11. Pitfalls of invasive blood pressure monitoring using the caudal ventral artery in rats

    PubMed Central

    Ohta, Hiroki; Ohki, Takao; Kanaoka, Yuji; Koizumi, Makoto; Okano, Hirotaka J.

    2017-01-01

    During rodent experiments, the caudal ventral artery (CVA) is useful for blood pressure (BP) measurement. However, CVA measurements may not reflect the true BP. This study was performed to verify the site-specific accuracy of invasive arterial BP monitoring during surgery in rats. Invasive arterial BP was simultaneously measured in rats via the CVA and the common carotid artery (CCA). The BP values were analysed while the rats were subjected to cooling of the head or tail. Additionally, the rats underwent digital subtraction angiography and histological examination of these arteries. The pressure difference was more significant in the tail cooling group than in the head cooling group. Digital subtraction angiography revealed that angiospasms occurred more frequently in the CVA than in the CCA upon cooling. This phenomenon was supported by histological analysis, which showed that the tunica media area was significantly larger in the CVA than in the CCA. CVA pressure is susceptible to environmental changes and may not accurately reflect the true BP without a strictly controlled laboratory environment. Therefore, understanding the pitfalls of this method is necessary to avoid cooling of the tail during BP measurement. PMID:28198822

  12. Surgical interventions with fatal outcome: utility of multi-phase postmortem CT angiography.

    PubMed

    Zerlauth, J-B; Doenz, F; Dominguez, A; Palmiere, C; Uské, A; Meuli, R; Grabherr, S

    2013-02-10

    Cases of fatal outcome after surgical intervention are autopsied to determine the cause of death and to investigate whether medical error caused or contributed to the death. For medico-legal purposes, it is imperative that autopsy findings are documented clearly. Modern imaging techniques such as multi-detector computed tomography (MDCT) and postmortem CT angiography, which is used for vascular system imaging, are useful tools for determining cause of death. The aim of this study was to determine the utility of postmortem CT angiography for the medico-legal death investigation. This study investigated 10 medico-legal cases with a fatal outcome after surgical intervention using multi-phase postmortem whole body CT angiography. A native CT scan was performed as well as three angiographic phases (arterial, venous, and dynamic) using a Virtangio(®) perfusion device and the oily contrast agent, Angiofil(®). The results of conventional autopsy were compared to those from the radiological investigations. We also investigated whether the radiological findings affected the final interpretation of cause-of-death. Causes of death were hemorrhagic shock, intracerebral hemorrhage, septic shock, and a combination of hemorrhage and blood aspiration. The diagnoses were made by conventional autopsy as well as by postmortem CT angiography. Hemorrhage played an important role in eight of ten cases. The radiological exam revealed the exact source of bleeding in seven of the eight cases, whereas conventional autopsy localized the source of bleeding only generally in five of the seven cases. In one case, neither conventional autopsy nor CT angiography identified the source of hemorrhage. We conclude that postmortem CT angiography is extremely useful for investigating deaths following surgical interventions. This technique helps document autopsy findings and allows a second examination if it is needed; specifically, it detects and visualizes the sources of hemorrhages in detail, which

  13. Identification of intraretinal neovascularization by high-speed indocyanine green angiography in idiopathic perifoveal telangiectasia.

    PubMed

    Soheilian, Masoud; Tavallali, Ali; Peyman, Gholam A

    2007-01-01

    Rapid advances in imaging technology have dramatically improved our understanding of the flow patterns of intraretinal circulation in normal and diseased states. To identify the angiographic features and flow pattern of retinal circulation in a patient with type 2 idiopathic perifoveal telangiectasia, dynamic simultaneous high-speed videoangiography using confocal scanning laser ophthalmoscopy was performed. This diagnostic tool provides enhanced anatomic resolution of retinal arterioles otherwise poorly defined by regular fluorescein and static indocyanine green angiography. High-speed indocyanine green angiography demonstrated dynamic flow abnormalities such as intraretinal neovascular complex and retino-retinal anastomosis in idiopathic perifoveal telangiectasia.

  14. Transient cortical blindness after coronary angiography: a case report and literature review.

    PubMed

    Akhtar, Naveed; Khatri, Isamil A; Naseer, Aamir; Ikram, Javeria; Ahmed, Waqas

    2011-03-01

    Transient cortical blindness after coronary angiography is a rarely encountered, rapidly progressive complication with complete return of vision within hours to up to five days.. Patients at risk include those undergoing coronary artery bypass graft study and those with renal failure. Although, the exact mechanism is not clear, the most likely explanation is a breakdown of blood brain barrier with direct neurotoxicity of the contrast media as most reported patients underwent coronary bypass graft study. We report a case of transient cortical blindness following diagnostic coronary angiography in a 39-year old patient with spontaneous recovery of vision within 1 hour.

  15. Transient cortical blindness: a benign but devastating complication after coronary angiography and graft study.

    PubMed

    Sridhar, Ganiga Srinivasaiah; Sadiq, Muhammad Athar; Wan Ahmad, Wan Azman; Supuramaniam, Chitra; Undok, Abdul Wahab; Abidin, Imran Zainal; Chee, Kok Han

    2014-10-01

    Transient cortical blindness after coronary angiography and bypass graft is a very rare complication. In this report we present the case of a 63-year-old man who developed transient cortical blindness within 30 minutes of coronary angioplasty and graft study, but subsequently recovered within 72 hours without any neurological deficit. A plain computed tomography brain scan showed bilateral symmetrical subarachnoid hyperdensities in the posterior cerebral circulation area suspicious of subarachnoid bleed. However, magnetic resonance imaging and magnetic resonance angiography scans were normal. Excess contrast volume causing direct neurotoxicity seems to be the most probable cause, but the exact mechanism is unclear.

  16. Anatomic and functional imaging of congenital heart disease with digital subtraction angiography

    SciTech Connect

    Buonocore, E.; Pavlicek, W.; Modic, M.T.; Meaney, T.F.; O'Donovan, P.B.; Grossman, L.B.; Moodie, D.S.; Yiannikas, J.

    1983-06-01

    Digital subtraction angiography (DSA) of the heart was performed in 54 patients for the evaluation of congenital heart diagnostic images and accurate physiologic shunt data that compared favorably with catheter angiography and nuclear medicine studies. Retrospective analysis of this series of patients indicated that DSA studies contributed sufficient informantion to shorten significantly or modify cardiac catheterization in 85% (79/93) of the defects that were identified. Interatrial septal defects were particularly well diagnosed, with identification occurring in 10 of 10 cases, wheseas intraventricular septal defects were identified in only 6 of 9 patients. Evaluation of postsurgical patients was accurate in 19 of 20 cases.

  17. Segmentation of brain blood vessels using projections in 3-D CT angiography images.

    PubMed

    Babin, Danilo; Vansteenkiste, Ewout; Pizurica, Aleksandra; Philips, Wilfried

    2011-01-01

    Segmenting cerebral blood vessels is of great importance in diagnostic and clinical applications, especially in quantitative diagnostics and surgery on aneurysms and arteriovenous malformations (AVM). Segmentation of CT angiography images requires algorithms robust to high intensity noise, while being able to segment low-contrast vessels. Because of this, most of the existing methods require user intervention. In this work we propose an automatic algorithm for efficient segmentation of 3-D CT angiography images of cerebral blood vessels. Our method is robust to high intensity noise and is able to accurately segment blood vessels with high range of luminance values, as well as low-contrast vessels.

  18. Minimally invasive mediastinal surgery

    PubMed Central

    Melfi, Franca M. A.; Mussi, Alfredo

    2016-01-01

    In the past, mediastinal surgery was associated with the necessity of a maximum exposure, which was accomplished through various approaches. In the early 1990s, many surgical fields, including thoracic surgery, observed the development of minimally invasive techniques. These included video-assisted thoracic surgery (VATS), which confers clear advantages over an open approach, such as less trauma, short hospital stay, increased cosmetic results and preservation of lung function. However, VATS is associated with several disadvantages. For this reason, it is not routinely performed for resection of mediastinal mass lesions, especially those located in the anterior mediastinum, a tiny and remote space that contains vital structures at risk of injury. Robotic systems can overcome the limits of VATS, offering three-dimensional (3D) vision and wristed instrumentations, and are being increasingly used. With regards to thymectomy for myasthenia gravis (MG), unilateral and bilateral VATS approaches have demonstrated good long-term neurologic results with low complication rates. Nevertheless, some authors still advocate the necessity of maximum exposure, especially when considering the distribution of normal and ectopic thymic tissue. In recent studies, the robotic approach has shown to provide similar neurological outcomes when compared to transsternal and VATS approaches, and is associated with a low morbidity. Importantly, through a unilateral robotic technique, it is possible to dissect and remove at least the same amount of mediastinal fat tissue. Preliminary results on early-stage thymomatous disease indicated that minimally invasive approaches are safe and feasible, with a low rate of pleural recurrence, underlining the necessity of a “no-touch” technique. However, especially for thymomatous disease characterized by an indolent nature, further studies with long follow-up period are necessary in order to assess oncologic and neurologic results through minimally

  19. Invasive mycoses: diagnostic challenges.

    PubMed

    Ostrosky-Zeichner, Luis

    2012-01-01

    Despite the availability of newer antifungal drugs, outcomes for patients with invasive fungal infections (IFIs) continue to be poor, in large part due to delayed diagnosis and initiation of appropriate antifungal therapy. Standard histopathologic diagnostic techniques are often untenable in at-risk patients, and culture-based diagnostics typically are too insensitive or nonspecific, or provide results after too long a delay for optimal IFI management. Newer surrogate markers of IFIs with improved sensitivity and specificity are needed to enable earlier diagnosis and, ideally, to provide prognostic information and/or permit therapeutic monitoring. Surrogate assays should also be accessible and easy to implement in the hospital. Several nonculture-based assays of newer surrogates are making their way into the medical setting or are currently under investigation. These new or up-and-coming surrogates include antigens/antibodies (mannan and antimannan antibodies) or fungal metabolites (d-arabinitol) for detection of invasive candidiasis, the Aspergillus cell wall component galactomannan used to detect invasive aspergillosis, or the fungal cell wall component and panfungal marker β-glucan. In addition, progress continues with use of polymerase chain reaction- or other nucleic acid- or molecular-based assays for diagnosis of either specific or generic IFIs, although the various methods must be better standardized before any of these approaches can be more fully implemented into the medical setting. Investigators are also beginning to explore the possibility of combining newer surrogate markers with each other or with more standard diagnostic approaches to improve sensitivity, specificity, and capacity for earlier diagnosis, at a time when fungal burden is still relatively low and more responsive to antifungal therapy.

  20. Minimally invasive parathyroid surgery

    PubMed Central

    Noureldine, Salem I.; Gooi, Zhen

    2015-01-01

    Traditionally, bilateral cervical exploration for localization of all four parathyroid glands and removal of any that are grossly enlarged has been the standard surgical treatment for primary hyperparathyroidism (PHPT). With the advances in preoperative localization studies and greater public demand for less invasive procedures, novel targeted, minimally invasive techniques to the parathyroid glands have been described and practiced over the past 2 decades. Minimally invasive parathyroidectomy (MIP) can be done either through the standard Kocher incision, a smaller midline incision, with video assistance (purely endoscopic and video-assisted techniques), or through an ectopically placed, extracervical, incision. In current practice, once PHPT is diagnosed, preoperative evaluation using high-resolution radiographic imaging to localize the offending parathyroid gland is essential if MIP is to be considered. The imaging study results suggest where the surgeon should begin the focused procedure and serve as a road map to allow tailoring of an efficient, imaging-guided dissection while eliminating the unnecessary dissection of multiple glands or a bilateral exploration. Intraoperative parathyroid hormone (IOPTH) levels may be measured during the procedure, or a gamma probe used during radioguided parathyroidectomy, to ascertain that the correct gland has been excised and that no other hyperfunctional tissue is present. MIP has many advantages over the traditional bilateral, four-gland exploration. MIP can be performed using local anesthesia, requires less operative time, results in fewer complications, and offers an improved cosmetic result and greater patient satisfaction. Additional advantages of MIP are earlier hospital discharge and decreased overall associated costs. This article aims to address the considerations for accomplishing MIP, including the role of preoperative imaging studies, intraoperative adjuncts, and surgical techniques. PMID:26425454

  1. Coronary dominance and prognosis in patients undergoing coronary computed tomographic angiography: results from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry

    PubMed Central

    Gebhard, Catherine; Fuchs, Tobias A.; Stehli, Julia; Gransar, Heidi; Berman, Daniel S.; Budoff, Matthew J.; Achenbach, Stephan; Al-Mallah, Mouaz; Andreini, Daniele; Cademartiri, Filippo; Callister, Tracy Q.; Chang, Hyuk-Jae; Chinnaiyan, Kavitha M.; Chow, Benjamin J. W.; Cury, Ricardo C.; Delago, Augustin; Gomez, Millie J.; Hadamitzky, Martin; Hausleiter, Joerg; Hindoyan, Niree; Feuchtner, Gudrun; Kim, Yong-Jin; Leipsic, Jonathon; Lin, Fay Y.; Maffei, Erica; Pontone, Gianluca; Raff, Gilbert; Shaw, Leslee J.; Villines, Todd C.; Dunning, Allison M.; Min, James K.; Kaufmann, Philipp A.

    2015-01-01

    Aims Coronary computed tomographic angiography (CCTA) has become an important tool for non-invasive diagnosis of coronary artery disease (CAD). Coronary dominance can be assessed by CCTA; however, the predictive value of coronary dominance is controversially discussed. The aim of this study was to evaluate the prevalence and prognosis of coronary dominance in a large prospective, international multicentre cohort of patients undergoing CCTA. Methods and results The study population consisted of 6382 patients with or without CAD (47% females, 53% males, mean age 56.9 ± 12.3 years) who underwent CCTA and were followed over a period of 60 months. Right or left coronary dominance was determined. Right dominance was present in 91% (n = 5817) and left in 9% (n = 565) of the study population. At the end of follow-up, outcome in patients with obstructive CAD (>50% luminal stenosis) and right dominance was similar compared with patients with left dominance [hazard ratio (HR) 0.46, 95% CI 0.16–1.32, P = 0.15]. Furthermore, no differences were observed for the type of coronary dominance in patients with non-obstructive CAD (HR 0.95, 95% CI 0.41–2.21, P = 0.8962) or normal coronary arteries (HR 1.04, 95% CI 0.68–1.59, P = 0.9). Subgroup analysis in patients with left main disease revealed an elevated hazard of the combined endpoint for left dominance (HR 6.45, 95% CI 1.66–25.0, P = 0.007), but not for right dominance. Conclusion In our study population, survival after 5 years of follow-up did not differ significantly between patients with left or right coronary dominance. Thus, assessment of coronary vessel dominance by CCTA may not enhance risk stratification in patients with normal coronary arteries or obstructive CAD, but may add prognostic information for specific subpopulations. PMID:25744341

  2. [Significance of abdominal wall CT-angiography in planning DIEA perforator flaps, TRAM flaps and SIEA flaps].

    PubMed

    Fansa, H; Schirmer, S; Frerichs, O; Gehl, H B

    2011-04-01

    Muscle sparing TRAM flaps and DIEA perforator flaps are standard procedures for breast reconstruction. Recently CT-angiography has been established to evaluate perforator vessels pre-operatively. CT-angiography was introduced to our department in July 2009. In a retrospective analysis data of the last 20 patients (altogether 22 flaps) before CT-angiography introduction and the following 20 (also 22 flaps) patients after introduction of CT-angiography were analysed with regard to the ratio of TRAM to DIEP flaps, and the time required to raise the flaps. The same surgeon raised all flaps. As different surgeons performed dissection of the recipient site, anastomoses, and insertion of flaps, and patients received primary (with sentinel or complete lymphadenctomy) or secondary reconstructions, only the time required harvesting the flap was compared. Thus other influences on raising the flap were eliminated. DIEP flaps were harvested with one single perforator. If perfusion or was considered not to be safe via one single perforator a muscle sparing TRAM flap (ms2) was raised. Angiography was performed using a 64-slice multi-detector CT scanner. CT-angiography did not lead to an increased rate of DIEP flaps in relation to ms2-TRAM flaps. Harvesting time of all flap types with CT-angiography on average was 121 min, without CT-angiography 135 min. This was not significantly different. However, separate analysis of DIEP flaps and ms2-TRAM flaps revealed a significant advantage of CT-angiography based harvesting of DIEP flaps of 26 min: with CT-angiography 101 min vs. 127 min without CT-angiography (p<0.028). There were no significant differences for ms2-TRAM flaps. All scans showed course and branching, diameter and size of the inferior epigastric artery. If evident the superficial inferior epigastric artery (SIEA) was marked. Dosage was 292 mGy-606 mGy×cm dependent on body weight. CTDI was 6.8-14.7 mGy. CT-angiography is a reproducible and observer independent procedure

  3. Quantification of left coronary bifurcation angles and plaques by coronary computed tomography angiography for prediction of significant coronary stenosis: A preliminary study with dual-source CT

    PubMed Central

    Cui, Yue; Zeng, Wenjuan; Yu, Jie; Lu, Jing; Hu, Yuannan; Diao, Nan; Liang, Bo; Han, Ping; Shi, Heshui

    2017-01-01

    Purpose To evaluate the diagnostic performance of left coronary bifurcation angles and plaque characteristics for prediction of coronary stenosis by dual-source CT. Methods 106 patients suspected of coronary artery disease undergoing both coronary computed tomography angiography (CCTA) and invasive coronary angiography (CAG) within three months were included. Left coronary bifurcation angles including the angles between the left anterior descending artery and left circumflex artery (LAD-LCx), left main coronary artery and left anterior descending artery (LM-LAD), left main coronary artery and left circumflex artery (LM-LCx) were measured on CT images. CCTA plaque parameters were calculated by plaque analysis software. Coronary stenosis ≥ 50% by CAG was defined as significant. Results 106 patients with 318 left coronary bifurcation angles and 126 vessels were analyzed. The bifurcation angle of LAD-LCx was significantly larger in left coronary stenosis ≥ 50% than stenosis < 50%, and significantly wider in the non-calcified plaque group than calcified. Multivariable analyses showed the bifurcation angle of LAD-LCx was an independent predictor for significant left coronary stenosis (OR = 1.423, P = 0.002). In ROC curve analysis, LAD-LCx predicted significant left coronary stenosis with a sensitivity of 66.7%, specificity of 78.4%, positive predictive value of 85.2% and negative predictive value of 55.8%. The lipid plaque volume improved the diagnostic performance of CCTA diameter stenosis (AUC: 0.854 vs. 0.900, P = 0.045) in significant coronary stenosis. Conclusions The bifurcation angle of LAD-LCx could predict significant left coronary stenosis. Wider LAD-LCx is related to non-calcified lesions. Lipid plaque volume could improve the diagnostic performance of CCTA for coronary stenosis prediction. PMID:28346530

  4. Combining Coronary Angiography and Myocardial Perfusion by Computed Tomography in the Identification of Flow-Limiting Stenosis – The CORE320 study

    PubMed Central

    Magalhães, Tiago A.; Kishi, Satoru; George, Richard; Arbab-Zadeh, Armin; Vavere, Andrea; Cox, Christopher; Matheson, Matthew B.; Miller, Julie; Brinker, Jeffrey; Di Carli, Marcelo; Rybicki, Frank J.; Rochitte, Carlos E.; Clouse, Melvin; Lima, João A.C.

    2015-01-01

    Background The combination of coronary computed tomography angiography (CTA) and myocardial CT perfusion (CTP) is gaining increasing acceptance, but a standardized approach to be implemented in the clinical setting is necessary. Objectives To investigate the accuracy of a combined coronary CTA and myocardial CTP comprehensive protocol compared to coronary CTA alone, using a combination of invasive coronary angiography (ICA) and Single-Photon Emission Computed Tomography (SPECT) as reference. Methods Three-hundred eighty-one patients included in CORE320 trial were analyzed in this study. Flow-limiting stenosis was defined as the presence of ≥50% stenosis by ICA with a related perfusion deficit by SPECT. The combined CTA+CTP definition of disease was the presence of a ≥50% stenosis with a related perfusion deficit. All data sets were analyzed by two experienced readers, aligning anatomical findings by CTA with perfusion deficits by CTP. Results Mean patient age was 62±6 years (66% male), 27% with prior history of myocardial infarction. In a per-patient analysis, sensitivity for CTA alone was 93% specificity was 54%, positive predictive value (PPV) was 55%; negative predictive value (NPV) 93% and overall accuracy was 69%. After combining CTA and CTP, sensitivity was 78%, specificity 73%, NPV 64%; PPV 0.85% and overall accuracy was 75%. In a per-vessel analysis, overall accuracy of CTA alone was 73%as compared to 79% for the combination of CTA and CTP (p<0.0001 for difference). Conclusions Combining coronary CTA and myocardial CTP findings through a comprehensive protocol is feasible. While sensitivity is lower, specificity and overall accuracy are higher than assessment by coronary CTA when compared against a reference standard of stenosis with an associated perfusion deficit. PMID:25977111

  5. CT angiography of renal arteriovenous fistulae: a report of two cases.

    PubMed

    Abdel-Gawad, Ehab A; Housseini, Ahmed M; Cherry, Kenneth J; Bonatti, Hugo; Maged, Ismaeel M; Norton, Patrick T; Hagspiel, Klaus D

    2009-01-01

    Renal arteriovenous fistulas (AVFs) are rare abnormal communications between the arterial and venous circulations that can be congenital or acquired. We describe the multidetector computed tomography angiography (MDCTA) appearance of 2 cases of renal AVF, one with the cirsoid and one with the aneurysmal subtype, and the impact of these findings on therapeutic decision making and treatment follow-up.

  6. OCT Angiography Identification of Choroidal Neovascularization Secondary to Acute Zonal Occult Outer Retinopathy.

    PubMed

    Levison, Ashleigh L; Baynes, Kimberly; Lowder, Careen Y; Srivastava, Sunil K

    2016-01-01

    A 74-year-old female with acute zonal occult outer retinopathy presented with a new lesion suspicious for choroidal neovascularization (CNV) in her right eye. Optical coherence tomography angiography (OCTA) confirmed the presence of CNV. OCTA is a new imaging technique that may help guide diagnosis and management of choroidal neovascular membranes in uveitic diseases.

  7. Comparing Color Doppler Ultrasonography and Angiography to Assess Traumatic Arterial Injuries of the Extremities

    PubMed Central

    Pezeshki Rad, Masoud; Mohammadifard, Mahyar; Ravari, Hassan; Farrokh, Donya; Ansaripour, Emad; Saremi, Elena

    2015-01-01

    Background: Traumatic events are one of the major causes of arterial injuries. Physical examination is not a good predictor of the extent of injuries and arteriography is considered as the gold standard for this purpose. In the recent years, noninvasive modalities are increasingly replacing diagnostic arteriography. Color Doppler ultrasonography (USG) is an excellent method to investigate arterial diseases. Objectives: The present study aimed to evaluate the diagnostic value of color Doppler USG compared to conventional angiography in traumatic arterial injuries of extremities. Patients and Methods: Seventy-five patients with extremity trauma suspicious for arterial injury were examined by color Doppler USG just before angiography. Doppler pattern and flow states were assessed, then angiography was performed. The results of duplex USG were compared with angiography. Results: Color Doppler USG had a sensitivity of 95% and specificity of 98% in diagnosis of arterial injury. Positive and negative predictive values of Doppler USG were 92.5% and 94.2%, respectively. Conclusions: Color Doppler USG can be used as a reliable modality with acceptable sensitivity and specificity values to screen hemodynamically stable patients with limb trauma suspicious for arterial injury. PMID:25785180

  8. [The improved design of table operating box of digital subtraction angiography device].

    PubMed

    Qi, Xianying; Zhang, Minghai; Han, Fengtan; Tang, Feng; He, Lemin

    2009-12-01

    In this paper are analyzed the disadvantages of CGO-3000 digital subtraction angiography table Operating Box. The authors put forward a communication control scheme between single-chip microcomputer(SCM) and programmable logic controller(PLC). The details of hardware and software of communication are given.

  9. Flat-panel-detector-based volume tomographic angiography imaging: detector evaluation

    NASA Astrophysics Data System (ADS)

    Ning, Ruola; Zhang, Dinghua; Chen, Biao; Conover, David L.; Yu, Rongfeng

    1999-09-01

    Recent development of large area flat panel solid state detector arrays indicates that flat panel image sensors have some common potential advantages: compactness, absence of geometric distortion and veiling glare with the benefits of high resolution, high DQE, high frame rate and high dynamic range, small image lag (less than 1%) and excellent linearity (approximately 1%). The advantages of the new flat-panel detector make it a promising candidate for cone beam volume tomographic angiography imaging. The purpose of this study is to characterize a Selenium thin film transistor (STFT) flat panel detector-based imaging system for cone beam volume tomographic angiography imaging applications. A prototype STFT detector-based cone beam volume tomographic angiography imaging system has been designed and constructed based on the modification of a GE 8800 CT scanner. This system is evaluated using a vascular phantom with different x-ray spectra, different sizes of vessels and different iodine concentration levels. The results indicate that with the currently available STFT flat panel detector, 90 kVp is the optimal kVp to achieve the highest signal-to-noise ratio for volume tomographic angiography imaging and the low contrast resolution of the system is 4 mg/ml iodine for a 2 mm vessel.

  10. Value of CT angiography in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy

    PubMed Central

    Meng, Xiang-Jun; Mi, Qi-Wu; Hu, Tao; Zhong, Wei-De

    2015-01-01

    ABSTRACT Purpose: To evaluate the clinical value of computed tomography angiography (CTA) in reducing the risk of hemorrhage associated with mini-percutaneous nephrolithotomy (PCNL). Materials and Methods: A total of 158 patients with renal or ureter stones who had undergone mini-percutaneous nephrolithotomy were retrospectively enrolled into this study from May of 2011 to April of 2014. Group 1 (65 patients) underwent computed tomography angiography, and Group 2 (93 patients) underwent non-contrast CT. The clinical characteristics of the patients and hemorrhagic complications were recorded. The hematologic complications (transfusion rate, and preoperative and postoperative hemoglobin values) were assessed. Results: There were no statistically significant differences in age, body mass index(BMI), stone diameter, operative time, stone-free rate, and hospital stay between the 2 groups. In group 2, 1 patient (1.1%) developed a renal arteriovenous fistula and was treated with embolus therapy. In addition, Group 2 showed significantly drop in hemoglobin (3.6 g/dL vs. 2.4 g/dL, respectively; P <0.001) and more transfusions (9.7% vs. 1.5%, respectively; P <0.05) compared with Group 1. Conclusion: The study showed that patients who underwent computed tomography angiography prior to percutaneous nephrolithotomy had lower drop of hemoglobin and needed less transfusions. These findings may suggest that the use of computed tomography angiography may reduce the risk of bleeding during percutaneous nephrolithotomy. PMID:26401861

  11. Retinal angiography: noninvasive, real-time bubble assessment from the ocular fundus.

    PubMed

    Parsons, J Travis; Smith, Cameron R; Zhu, Jiepei; Spiess, Bruce D

    2009-01-01

    Formation of bubbles in tissue and vasculature from a sudden reduction in ambient pressure is likely an underlying cause of the clinical symptoms of decompression sickness (DCS). Thus, tools detecting bubbles in the vasculature may be important for evaluating DCS. Sheep were air-compressed to 6.0 ATA (30 minutes bottom time) then rapidly decompressed to the surface. A fundus camera was quickly positioned for continuous observation of the retinal vasculature. Bubbles were observed in the retinal vasculature of 25.8% (n = 31) of the sheep. Bubble onset time ranged from 5-22 minutes post-chamber and lodge time ranged from 0-70+ minutes. Bubbles were visualized mostly in the arteries of the retinal circulation. Severe vasoconstriction was captured using red-free angiography in two sheep. In two other sheep, fluorescein angiography demonstrated occluded blood flow caused by arterial gas emboli. This study demonstrates that retinal angiography is a practical tool for real-time, noninvasive detection of bubbles in the retinal circulation, a visible window to the cerebral circulation. Thus retinal angiography may prove invaluable in the early detection of arterial gas emboli in the cerebral circulation, the resolution of which is imperative to favorable neurological outcomes. This study also presents for the first time images of bubbles in the retinal circulation associated with DCS captured by a fundus camera.

  12. Rest and exercise radionuclide angiography for diagnosis in chronic ischemic heart disease

    SciTech Connect

    Gibbons, R.J. )

    1991-09-01

    Rest and exercise radionuclide angiography is frequently employed for the diagnosis of chest pain syndromes. Its value and limitations in this regard have been well studied, but proper utilization of the technique requires an understanding of five critical concepts: (1) Radionuclide angiography is superior to treadmill exercise testing and probably equivalent to thallium scintigraphy, although the published series did not use current methods. (2) The true specificity of radionuclide angiography is about 80%, intermediate between the early optimistic estimates and the later pessimistic ones. (3) The peak exercise ejection fraction is the preferred test parameter for diagnosis, although exercise hemodynamics, symptoms, and electrocardiographic changes should also be considered. (4) Although radionuclide angiography is clearly helpful for noninvasive diagnosis, significant numbers of patients will continue to fall in an uncertain category. (5) The proper application of the technique requires recognition of its limitations and careful attention to technical details. When properly applied, this modality can make an important contribution to clinical decision making. 58 references.

  13. Failing Hemodialysis Arteriovenous Fistula and Percutaneous Treatment: Imaging with CT, MRI and Digital Subtraction Angiography

    SciTech Connect

    Cavagna, Enrico; D'Andrea, Paolo; Schiavon, Francesco; Tarroni, Giovanni

    2000-07-15

    Purpose: To evaluate failing hemodialysis arteriovenous fistulas with helical CT angiography (CTA), MR angiography (MRA), and digital subtraction angiography (DSA), and to compare the efficacy of the three techniques in detecting the number, location, grade, and extent of stenoses and in assessing the technical results of percutaneous transluminal angioplasty (PTA) and stenting.Methods: Thirteen patients with Brescia-Cimino arteriovenous fistula malfunction underwent MRA and CTA of the fistula and, within 1 week, DSA. A total of 11 PTAs were performed; in three cases an MR-compatible stent was placed. DSA served as the gold standard for comparison in all patients. The presence, site, and number of stenoses or occlusions and the technical results of percutaneous procedures were assessed with DSA, CTA, and MRA.Results: MRA underestimated a single stenosis in one patient; CTA and MRA did not overestimate any stenosis. Significant artifacts related to stent geometry and/or underlying metal were seen in MRA sequences in two cases.Conclusions: CT and MRI can provide information regarding the degree of vascular impairment, helping to stratify patients into those who can have PTA (single or multiple stenoses) versus those who require an operative procedure (occlusion). Conventional angiography can be reserved for candidates for percutaneous intervention.

  14. Detection of hemorrhage source: the diagnostic value of post-mortem CT-angiography.

    PubMed

    Palmiere, C; Binaghi, S; Doenz, F; Bize, P; Chevallier, C; Mangin, P; Grabherr, S

    2012-10-10

    The aim of this study was to compare the diagnostic value of post-mortem computed tomography angiography (PMCTA) to conventional, ante-mortem computed tomography (CT)-scan, CT-angiography (CTA) and digital subtraction angiography (DSA) in the detection and localization of the source of bleeding in cases of acute hemorrhage with fatal outcomes. The medical records and imaging scans of nine individuals who underwent a conventional, ante-mortem CT-scan, CTA or DSA and later died in the hospital as a result of an acute hemorrhage were reviewed. Post-mortem computed tomography angiography, using multi-phase post-mortem CTA, as well as medico-legal autopsies were performed. Localization accuracy of the bleeding was assessed by comparing the diagnostic findings of the different techniques. The results revealed that data from ante-mortem and post-mortem radiological examinations were similar, though the PMCTA showed a higher sensitivity for detecting the hemorrhage source than did ante-mortem radiological investigations. By comparing the results of PMCTA and conventional autopsy, much higher sensitivity was noted in PMCTA in identifying the source of the bleeding. In fact, the vessels involved were identified in eight out of nine cases using PMCTA and only in three cases through conventional autopsy. Our study showed that PMCTA, similar to clinical radiological investigations, is able to precisely identify lesions of arterial and/or venous vessels and thus determine the source of bleeding in cases of acute hemorrhages with fatal outcomes.

  15. MR-angiography allows defining severity grades of cerebral vasospasm in an experimental double blood injection subarachnoid hemorrhage model in rats

    PubMed Central

    Malinova, Vesna; Psychogios, Marios N.; Tsogkas, Ioannis; Koennecke, Birte; Bleuel, Kim; Iliev, Bogdan; Rohde, Veit; Mielke, Dorothee

    2017-01-01

    Objective Magnetic resonance (MR) imaging has been used for the detection of cerebral vasospasm (VSP) related infarction in experimental subarachnoid hemorrhage (eSAH) in rats. Conventional angiography is generally used to visualize VSP, which is an invasive technique with a possible increase in morbidity and mortality. In this study we evaluated the validity of MR-angiography (MRA) in detecting VSP and its feasibility to define VSP severity grades after eSAH in rats. Methods SAH was induced using the double-hemorrhage model in 12 rats. In two rats, saline solution was injected instead of blood (sham group). MR was performed on day 1, 2 and on day 5. T1-, T2-, T2*-weighted and time-of-flight MR sequences were applied, which were analyzed by two blinded neuroradiologists. Vessel narrowing of 25–50% was defined as mild, 50–75% as moderate and >75% as severe VSP. Results We performed a total of 34 MRAs in 14 rats. In 14 rats, MRA was performed on day 2 and day 5. In six rats MRA was additionally performed on day1 before the blood injection. A good visualization of cerebral vessels was possible in all cases. No VSP was seen in the sham group neither on day 2 nor on day 5. We found vasospasm on day 2 in 7 of the 14 rats (50%) whereas all 7 rats had mild and one rat had additionally moderate and severe vasospasm in one vessel, respectively. On day 5 we found vasospasm in 8 of the 14 rats (60%) whereas 4 rats had severe vasospasm, 1 rat had moderate vasospasm and 3 rats demonstrated mild vasospasm. In 4 of the 14 rats (30%) an ischemic lesion was detected on day 5. Three of these rats had severe vasospasm and one rat had mild vasospasm. Severe vasospasm on day 5 was statistically significant correlated with the occurrence of ischemic lesions (Fisher’s Exact test, OR 19.5, p = 0.03). Conclusions MRA is a noninvasive diagnostic tool, which allows a good visualization of the cerebral vasculature and provides reproducible results concerning the detection of VSP and the

  16. Ultra-high-sensitive optical micro-angiography provides depth resolved visualization of microcirculations within human skin under psoriatic conditions

    NASA Astrophysics Data System (ADS)

    Qin, Jia; An, Lin; Wang, Ruikang

    2011-03-01

    Adequate functioning of the peripheral micro vascular in human skin is necessary to maintain optimal tissue perfusion and preserve normal hemodynamic function. There is a growing body of evidence suggests that vascular abnormalities may directly related to several dermatologic diseases, such as psoriasis, port-wine stain, skin cancer, etc. New in vivo imaging modalities to aid volumetric microvascular blood perfusion imaging are there for highly desirable. To address this need, we demonstrate the capability of ultra-high sensitive optical micro angiography to allow blood flow visualization and quantification of vascular densities of lesional psoriasis area in human subject in vivo. The microcirculation networks of lesion and non-lesion skin were obtained after post processing the data sets captured by the system. With our image resolution (~20 μm), we could compare these two types of microcirculation networks both qualitatively and quantitatively. The B-scan (lateral or x direction) cross section images, en-face (x-y plane) images and the volumetric in vivo perfusion map of lesion and non-lesion skin areas were obtained using UHS-OMAG. Characteristic perfusion map features were identified between lesional and non-lesional skin area. A statistically significant difference between vascular densities of lesion and non-lesion skin area was also found using a histogram based analysis. UHS-OMAG has the potential to differentiate the normal skin microcirculation from abnormal human skin microcirculation non-invasively with high speed and sensitivity. The presented data demonstrates the great potential of UHS-OMAG for detecting and diagnosing skin disease such as psoriasis in human subjects.

  17. ESTIMATION OF CARDIAC CT ANGIOGRAPHY RADIATION DOSE TOWARD THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVEL FOR CCTA IN IRAN.

    PubMed

    Hosseini Nasab, Seyed Mohammad Bagher; Shabestani-Monfared, Ali; Deevband, Mohammad Reza; Paydar, Reza; Nabahati, Mehrdad

    2016-08-29

    In recent years, with the introduction of 64-slice CT and dual-source CT technology, coronary CT angiography (CCTA) has emerged as a useful diagnostic imaging modality as a non-invasive assessment of coronary heart disease. CT produces a larger radiation dose than other imaging tests and cardiac CT involves higher radiation dose with the advances in the spatial and temporal resolution. The aims of this study are patient dose assessment and establishment of national diagnostic reference level for CCTA in Iran. A questionnaire was sent to CCTA centers. Data for patient and CT protocols were obtained. The volumetric CT dose index (CTDIvol), dose length product (DLP) and total DLP were considered in the 32 cm standard body phantom. Calculation of estimated effective dose (ED) was obtained by multiplying the DLP by a conversion factor [k = 0.014 mSv (mGy·cm)(-1)]. Mean value of CTDIvol and DLP for CCTA was 50 mGy and 825 mGy·cm. The third quartile (75th) of the distribution of mean CTDIvol (66.54 mGy) and DLP (1073 mGy·cm) values was expressed as the diagnostic reference level (DRL) for CCTA in Iran. The median of ED was 10.26 mSv and interquartile range of ED was 7.08-15.03 mSv. A large variety in CTDIvol and DLP among CT scanner and different sites due to variability in CT parameter is noted. It seems that training could help to reduce patient's dose.

  18. Malignant cancer and invasive placentation

    PubMed Central

    D'Souza, Alaric W.; Wagner, Günter P.

    2014-01-01

    Cancer metastasis is an invasive process that involves the transplantation of cells into new environments. Since human placentation is also invasive, hypotheses about a relationship between invasive placentation in eutherian mammals and metastasis have been proposed. The relationship between metastatic cancer and invasive placentation is usually presented in terms of antagonistic pleiotropy. According to this hypothesis, evolution of invasive placentation also established the mechanisms for cancer metastasis. Here, in contrast, we argue that the secondary evolution of less invasive placentation in some mammalian lineages may have resulted in positive pleiotropic effects on cancer survival by lowering malignancy rates. These positive pleiotropic effects would manifest themselves as resistance to cancer cell invasion. To provide a preliminary test of this proposal, we re-analyze data from Priester and Mantel (Occurrence of tumors in domestic animals. Data from 12 United States and Canadian colleges of veterinary medicine. J Natl Cancer Inst 1971;47:1333-44) about malignancy rates in cows, horses, cats and dogs. From our analysis we found that equines and bovines, animals with less invasive placentation, have lower rates of metastatic cancer than felines and canines in skin and glandular epithelial cancers as well as connective tissue sarcomas. We conclude that a link between type of placentation and species-specific malignancy rates is more likely related to derived mechanisms that suppress invasion rather than different degrees of fetal placental aggressiveness. PMID:25324490

  19. Zinn-Haller arterial ring observed by ICG angiography in high myopia

    PubMed Central

    Ohno-Matsui, K.; Futagami, S.; Yamashita, S.; Tokoro, T.

    1998-01-01

    AIMS—To delineate the entire Zinn-Haller arterial ring angiographically in vivo.
METHODS—382 highly myopic eyes (210 patients) with refractive errors greater than −8.25 D were examined using indocyanine green (ICG) videoangiography. A control group of 80 eyes (40 patients) had refractive errors within plano +/− 3 D.
RESULTS—The Zinn-Haller ring was visible in 206 of 382 highly myopic eyes (53.9%) by ICG angiography. Although only a part of the Zinn-Haller ring was visible in 162 of 206 eyes, in the remaining 44 eyes it was observed almost completely around the optic nerve head. No anastomotic channels between lateral and medial short posterior ciliary arteries were filled by ICG angiography. In 22 of the 44 eyes (50.0%) the Zinn-Haller ring was supplied by branches of the lateral and medial short posterior ciliary arteries; in seven eyes, it was supplied only by the lateral short posterior ciliary artery; and in seven eyes, it was supplied only by the medial short posterior ciliary artery. In none of the control subjects was the Zinn-Haller ring visible by ICG angiography.
CONCLUSIONS—The Zinn-Haller ring observed by ICG angiography was not a complete collateral circle between lateral and medial posterior ciliary arteries. Also, the patterns in supply vessels to the Zinn-Haller ring varied. ICG angiography made possible the detailed observation of the Zinn-Haller ring in human eyes in vivo.

 Keywords: Zinn-Haller circle; blood flow; optic nerve head; myopia PMID:9930263

  20. Digital angiography in the pediatric patient with congenital heart disease: comparison with standard methods

    SciTech Connect

    Levin, A.R.; Goldberg, H.L.; Borer, J.S.; Rothenberg, L.N.; Nolan, F.A.; Engle, M.A.; Cohen, B.; Skelly, N.T.; Carter, J.

    1983-08-01

    Digital subtraction angiography (DSA) permits high-resolution cardiac imaging with relatively low doses of contrast medium and reduced radiation exposure. These are potential advantages in children with congenital heart disease. Computer-based DSA (30 frames/sec) and conventional cutfilm angiography (6 frames/sec) or cineangiography (60 frames/sec) were compared in 42 patients, ages 2 months to 18 years (mean 7.8 years) and weighing 3.4 to 78.5 kg (mean 28.2 kg). There were 29 diagnoses that included valvular regurgitant lesions, obstructive lesions, various shunt abnormalities, and a group of miscellaneous anomalies. For injections made at a site distant from the lesion and on the right side of the circulation, the mean dose of contrast medium was 60% to 100% of the conventional dose given during standard angiography. With injections made close to the lesion and on the left side of the circulation, the mean dose of contrast medium was 27.5% to 42% of the conventional dose. Radiation exposure for each technique was markedly reduced in all age groups. A total of 92 digital subtraction angiograms were performed. Five studies were suboptimal because too little contrast medium was injected; in the remaining 87 injections, DSA and conventional studies resulted in identical diagnoses in 81 instances (p less than .001 vs chance). The remaining six injections made during DSA failed to confirm diagnoses made angiographically by standard cutfilm angiography or cineangiography. We conclude that DSA usually provides diagnostic information equivalent to that available from cutfilm angiography and cineangiography, but DSA requires considerably lower doses of contrast medium and less radiation exposure than standard conventional methods.

  1. Predictive Capability of Near-Infrared Fluorescence Angiography in Submental Perforator Flap Survival

    PubMed Central

    Matsui, Aya; Lee, Bernard T.; Winer, Joshua H.; Laurence, Rita G.; Frangioni, John V.

    2010-01-01

    Background Perforator flaps have become increasingly popular in reconstructive surgery as patients experience less donor-site morbidity than with conventional musculocutaneous flaps. Previously, our laboratory described the intraoperative use of near-infrared (NIR) fluorescence angiography for patient-specific perforator-flap design. This study evaluates the predictive capability of NIR fluorescence angiography for flap survival in submental flap reconstruction. Methods NIR angiography was performed using indocyanine green at 0, 0.5, 24, 48, and 72 h post-surgery after flap creation in 12 pigs. A single perforator artery was preserved during flap creation based on location (central or non-central) and dominance (dominant or non-dominant). Venous drainage, arterial perfusion, and perfused area as percentage of total flap were analyzed. Clinical assessments of perfusion were compared with those made using NIR imaging and histology. Results Use of NIR fluorescence angiography immediately after flap creation accurately predicted areas of perfusion at 72 h (p = 0.0013), compared to the initial clinical assessment (p = 0.3085). Identification of necrosis by histology at 72 h correlated with NIR findings of insufficient arterial perfusion immediately after flap creation. No statistically significant differences in perfusion metrics were detected based on location or dominance of the preserved perforator; however, flaps containing central perforators had a higher percent perfused area than those with non-central perforators. Conclusions The use of NIR angiography immediately after flap creation can predict areas of perfusion at 72 h. This predictive capability may permit intraoperative revision of compromised flaps that have a high likelihood of failure. PMID:21042109

  2. Automatic segmentation and co-registration of gated CT angiography datasets: measuring abdominal aortic pulsatility

    NASA Astrophysics Data System (ADS)

    Wentz, Robert; Manduca, Armando; Fletcher, J. G.; Siddiki, Hassan; Shields, Raymond C.; Vrtiska, Terri; Spencer, Garrett; Primak, Andrew N.; Zhang, Jie; Nielson, Theresa; McCollough, Cynthia; Yu, Lifeng

    2007-03-01

    Purpose: To develop robust, novel segmentation and co-registration software to analyze temporally overlapping CT angiography datasets, with an aim to permit automated measurement of regional aortic pulsatility in patients with abdominal aortic aneurysms. Methods: We perform retrospective gated CT angiography in patients with abdominal aortic aneurysms. Multiple, temporally overlapping, time-resolved CT angiography datasets are reconstructed over the cardiac cycle, with aortic segmentation performed using a priori anatomic assumptions for the aorta and heart. Visual quality assessment is performed following automatic segmentation with manual editing. Following subsequent centerline generation, centerlines are cross-registered across phases, with internal validation of co-registration performed by examining registration at the regions of greatest diameter change (i.e. when the second derivative is maximal). Results: We have performed gated CT angiography in 60 patients. Automatic seed placement is successful in 79% of datasets, requiring either no editing (70%) or minimal editing (less than 1 minute; 12%). Causes of error include segmentation into adjacent, high-attenuating, nonvascular tissues; small segmentation errors associated with calcified plaque; and segmentation of non-renal, small paralumbar arteries. Internal validation of cross-registration demonstrates appropriate registration in our patient population. In general, we observed that aortic pulsatility can vary along the course of the abdominal aorta. Pulsation can also vary within an aneurysm as well as between aneurysms, but the clinical significance of these findings remain unknown. Conclusions: Visualization of large vessel pulsatility is possible using ECG-gated CT angiography, partial scan reconstruction, automatic segmentation, centerline generation, and coregistration of temporally resolved datasets.

  3. Invasive and minimally invasive surgical techniques for back pain conditions.

    PubMed

    Lavelle, William; Carl, Allen; Lavelle, Elizabeth Demers

    2007-12-01

    This article summarizes current issues related to invasive and minimally invasive surgical techniques for back pain conditions. It describes pain generators and explains theories about how discs fail. The article discusses techniques for treating painful sciatica, painful motion segments, and spinal stenosis. Problems related to current imaging are also presented. The article concludes with a discussion about physical therapy.

  4. [Study on Reduction of Radiation Exposure by Using Carbon Dioxide Angiography Catheter in Vascular Access Intervention Therapy(VAIVT)].

    PubMed

    Tsukada, Yasunori; Kakuchi, Yasushi

    2015-09-01

    In vascular access intervention therapy (VAIVT), carbon dioxide is used as negative contrast medium for patients with iodine allergy or for those who have vascular access but not started with dialysis yet and have not endangered their remaining kidney function. To capture the movement of jet-injected carbon dioxide during the carbon dioxide angiography, we performed imaging at a rate of 15 frames per second. This method has a higher level of radiation exposure than angiography using an iodine contrast medium. Therefore we developed a catheter with 20 helical side holes in the tip (carbon dioxide angiography catheter), which allows large numbers of tiny bubbles to be generated simultaneously. In our study, we evaluate whether the use of this catheter can reduce the number of frames taken per second thus reducing the radiation exposure. A comparative experiment with existing angiography catheters with no side holes suggested that the use of this carbon dioxide angiography catheter to be useful for reducing the radiation exposure to patients and operators. Moreover, angiography using this catheter is highly useful from viewpoint of improving the stenotic vesselvisibility and reducing the side effects of using carbon dioxide, and we expect that the carbon dioxide angiography method is effective for patients and operators.

  5. Dietary Flexibility Aids Asian Earthworm Invasion in North American Forests

    EPA Science Inventory

    On a local scale, invasiveness of introduced species and invasibility of habitats together determine invasion success. A key issue in invasion ecology has been how to quantify the contribution of species invasiveness and habitat invasibility separately. Conventional approaches, s...

  6. Defining an invasive species.

    PubMed

    Moutou, F; Pastoret, P P

    2010-04-01

    The definition of an invasive species will depend on the viewpoint of the observer, who in some cases may be responsible for introducing the species. History has taught us that humans are the species that has invaded the largest surface area of the planet. So, before going on to propose a few definitions, this article describes three different examples or types of example in which domestic animal species, wild animal species and microorganisms (for biological pest control) have been transported intentionally. By doing so, this paper uses a variety of situations to support the definitions. A contemporary argument would counter a strictly biogeographical definition with a more ecological definition. The two are probably complementary. In any case, these definitions should remain practical. The consequences of species movements vary. However, their health impacts should not be underestimated.

  7. Minimally invasive valve surgery.

    PubMed

    Woo, Y Joseph; Seeburger, Joerg; Mohr, Friedrich W

    2007-01-01

    As alternatives to standard sternotomy, surgeons have developed innovative, minimally invasive approaches to conducting valve surgery. Through very small skin incisions and partial upper sternal division for aortic valve surgery and right minithoracotomy for mitral surgery, surgeons have become adept at performing complex valve procedures. Beyond cosmetic appeal, apparent benefits range from decreased pain and bleeding to improved respiratory function and recovery time. The large retrospective studies and few small prospective randomized studies are herein briefly summarized. The focus is then directed toward describing specific intraoperative technical details in current clinical use, covering anesthetic preparation, incision, mediastinal access, cardiovascular cannulation, valve exposure, and valve reconstruction. Finally, unique situations such as pulmonic valve surgery, reoperations, beating heart surgery, and robotics are discussed.

  8. Transanal Minimally Invasive Surgery

    PubMed Central

    deBeche-Adams, Teresa; Nassif, George

    2015-01-01

    Transanal minimally invasive surgery (TAMIS) was first described in 2010 as a crossover between single-incision laparoscopic surgery and transanal endoscopic microsurgery (TEM) to allow access to the proximal and mid-rectum for resection of benign and early-stage malignant rectal lesions. The TAMIS technique can also be used for noncurative intent surgery of more advanced lesions in patients who are not candidates for radical surgery. Proper workup and staging should be done before surgical decision-making. In addition to the TAMIS port, instrumentation and set up include readily available equipment found in most operating suites. TAMIS has proven its usefulness in a wide range of applications outside of local excision, including repair of rectourethral fistula, removal of rectal foreign body, control of rectal hemorrhage, and as an adjunct in total mesorectal excision for rectal cancer. TAMIS is an easily accessible, technically feasible, and cost-effective alternative to TEM. PMID:26491410

  9. Minimally invasive esophagectomy

    PubMed Central

    Herbella, Fernando A; Patti, Marco G

    2010-01-01

    Esophageal resection is associated with a high morbidity and mortality rate. Minimally invasive esophagectomy (MIE) might theoretically decrease this rate. We reviewed the current literature on MIE, with a focus on the available techniques, outcomes and comparison with open surgery. This review shows that the available literature on MIE is still crowded with heterogeneous studies with different techniques. There are no controlled and randomized trials, and the few retrospective comparative cohort studies are limited by small numbers of patients and biased by historical controls of open surgery. Based on the available literature, there is no evidence that MIE brings clear benefits compared to conventional esophagectomy. Increasing experience and the report of larger series might change this scenario. PMID:20698044

  10. [Invasive gastroenteritis, anything new?].

    PubMed

    Echeita Sarrionandia, M Aurora; León, Silvia Herrera; Baamonde, Cristina Simón

    2011-03-01

    Invasive gastroenteritis is characterized by fever and inflammatory diarrhea and can be caused by nontyphoideal Salmonella serotypes and Shigella spp.-enteroinvasive Escherichia coli (EIEC), among other pathogens. This review describes emerging monophasic variants of Salmonella enterica serotype 1,4,[5],12:i:- and provides an evolutionary consideration of Shigella spp.-EIEC as a single pathotype. In 1997, a monophasic variant of S. enterica serotype 1,4,[5],12:i:-, phage-type U302, multidrug resistant (ACGSSuTSxT), lacking the fljBA operon, appeared in Spain constituting a "Spanish" clonal line. Subsequently, strains of S. 4[5],12:i:-, of different phage types with a new resistance genomic island (ASSuT) were detected in Italy, forming part of a European clonal line. Finally, an "American" clonal line with a deletion of fljBA different from the Spanish clonal line appeared. Therefore, probably by convergent evolution, different clonal lines of Salmonella 1,4,[5],12:i:-, which can carry resistance genes on chromosomes or plasmids, with Salmonella Typhimurium as ancestor, have emerged in the world. Although Shigella belongs to the E. coli species and despite the biological inconsistency involved, this genus has traditionally been considered to cause bacillary dysentery. The EIEC group shares virulence mechanisms and clinical manifestations with Shigella. Both lack some metabolic genes and harbor similar plasmids of invasion. Shigella spp. and EIEC evolved from independent clonal lines of E. coli, by horizontal acquisition of virulence factors, forming a single pathotype. IpaH gene detection is an alternative to attribute the corresponding pathogenic role to non-agglutinable strains that are biochemically compatible with Shigella spp.

  11. Integrated assessment of biological invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the main annalists of the ecological and economic impacts of invasions on ecosystems around the world, ecologists should be able to provide information that can guide management practices. Managers often want to know about the potential for invasion of specific organisms in the sites under their ...

  12. Spread dynamics of invasive species

    PubMed Central

    Arim, Matías; Abades, Sebastián R.; Neill, Paula E.; Lima, Mauricio; Marquet, Pablo A.

    2006-01-01

    Species invasions are a principal component of global change, causing large losses in biodiversity as well as economic damage. Invasion theory attempts to understand and predict invasion success and patterns of spread. However, there is no consensus regarding which species or community attributes enhance invader success or explain spread dynamics. Experimental and theoretical studies suggest that regulation of spread dynamics is possible; however, the conditions for its existence have not yet been empirically demonstrated. If invasion spread is a regulated process, the structure that accounts for this regulation will be a main determinant of invasion dynamics. Here we explore the existence of regulation underlying changes in the rate of new site colonization. We employ concepts and analytical tools from the study of abundance dynamics and show that spread dynamics are, in fact, regulated processes and that the regulation structure is notably consistent among invasions occurring in widely different contexts. We base our conclusions on the analysis of the spread dynamics of 30 species invasions, including birds, amphibians, fish, invertebrates, plants, and a virus, all of which exhibited similar regulation structures. In contrast to current beliefs that species invasions are idiosyncratic phenomena, here we provide evidence that general patterns do indeed exist. PMID:16387862

  13. Comparison of Fractional Flow Reserve Based on Computational Fluid Dynamics Modeling Using Coronary Angiographic Vessel Morphology Versus Invasively Measured Fractional Flow Reserve.

    PubMed

    Tröbs, Monique; Achenbach, Stephan; Röther, Jens; Redel, Thomas; Scheuering, Michael; Winneberger, David; Klingenbeck, Klaus; Itu, Lucian; Passerini, Tiziano; Kamen, Ali; Sharma, Puneet; Comaniciu, Dorin; Schlundt, Christian

    2016-01-01

    Invasive fractional flow reserve (FFRinvasive), although gold standard to identify hemodynamically relevant coronary stenoses, is time consuming and potentially associated with complications. We developed and evaluated a new approach to determine lesion-specific FFR on the basis of coronary anatomy as visualized by invasive coronary angiography (FFRangio): 100 coronary lesions (50% to 90% diameter stenosis) in 73 patients (48 men, 25 women; mean age 67 ± 9 years) were studied. On the basis of coronary angiograms acquired at rest from 2 views at angulations at least 30° apart, a PC-based computational fluid dynamics modeling software used personalized boundary conditions determined from 3-dimensional reconstructed angiography, heart rate, and blood pressure to derive FFRangio. The results were compared with FFRinvasive. Interobserver variability was determined in a subset of 25 narrowings. Twenty-nine of 100 coronary lesions were hemodynamically significant (FFRinvasive ≤ 0.80). FFRangio identified these with an accuracy of 90%, sensitivity of 79%, specificity of 94%, positive predictive value of 85%, and negative predictive value of 92%. The area under the receiver operating characteristic curve was 0.93. Correlation between FFRinvasive (mean: 0.84 ± 0.11) and FFRangio (mean: 0.85 ± 0.12) was r = 0.85. Interobserver variability of FFRangio was low, with a correlation of r = 0.88. In conclusion, estimation of coronary FFR with PC-based computational fluid dynamics modeling on the basis of lesion morphology as determined by invasive angiography is possible with high diagnostic accuracy compared to invasive measurements.

  14. Optimization of 4D vessel‐selective arterial spin labeling angiography using balanced steady‐state free precession and vessel‐encoding

    PubMed Central

    Schmitt, Peter; Bi, Xiaoming; Chappell, Michael A.; Tijssen, Rob H. N.; Sheerin, Fintan; Miller, Karla L.; Jezzard, Peter

    2016-01-01

    Vessel‐selective dynamic angiograms provide a wealth of useful information about the anatomical and functional status of arteries, including information about collateral flow and blood supply to lesions. Conventional x‐ray techniques are invasive and carry some risks to the patient, so non‐invasive alternatives are desirable. Previously, non‐contrast dynamic MRI angiograms based on arterial spin labeling (ASL) have been demonstrated using both spoiled gradient echo (SPGR) and balanced steady‐state free precession (bSSFP) readout modules, but no direct comparison has been made, and bSSFP optimization over a long readout period has not been fully explored. In this study bSSFP and SPGR are theoretically and experimentally compared for dynamic ASL angiography. Unlike SPGR, bSSFP was found to have a very low ASL signal attenuation rate, even when a relatively large flip angle and short repetition time were used, leading to a threefold improvement in the measured signal‐to‐noise ratio (SNR) efficiency compared with SPGR. For vessel‐selective applications, SNR efficiency can be further improved over single‐artery labeling methods by using a vessel‐encoded pseudo‐continuous ASL (VEPCASL) approach. The combination of a VEPCASL preparation with a time‐resolved bSSFP readout allowed the generation of four‐dimensional (4D; time‐resolved three‐dimensional, 3D) vessel‐selective cerebral angiograms in healthy volunteers with 59 ms temporal resolution. Good quality 4D angiograms were obtained in all subjects, providing comparable structural information to 3D time‐of‐flight images, as well as dynamic information and vessel selectivity, which was shown to be high. A rapid 1.5 min dynamic two‐dimensional version of the sequence yielded similar image features and would be suitable for a busy clinical protocol. Preliminary experiments with bSSFP that included the extracranial vessels showed signal loss in regions of poor magnetic field

  15. The impact of geographical distances to coronary angiography laboratories on the patient evaluation pathways in patients with suspected coronary artery disease. Results from a population-based study in Hungary

    PubMed Central

    Király, Ferenc; Vassányi, István; Kósa, István

    2014-01-01

    Introduction Coronary artery disease (CAD) has been a leading cause of death in the western world for the last few decades, despite significant improvements in treatment and management. Diagnostic algorithms for the evaluation of patients with suspected CAD are based on available guidelines. Aim To evaluate the impact of geographical distances to coronary angiography laboratories on the patient evaluation pathways in patients with suspected CAD, from a population-based study in Hungary. Material and methods Depersonalised data of 29,202 patients identified by their pseudo-social security number were analysed. All patients underwent coronary angiography as an initial direct invasive investigation (DI) following an at least half-year-long stable period between 1 January 2004 and 31 December 2008. Results One hundred and thirty-five dominant primary cardiology centres (PCC) have been identified, from which 85 proved to have sample size more than 100 DIs in tertiary cardiology centres (TCC). The frequency of DIs showed a close correlation with PCC-TCC distances (r = –0.44, p < 0.001). A negative correlation could be demonstrated between the age of patients and PCC-TCC distances (r = –0.45, p < 0.001). Without significant change in the absolute mortality, the relative mortality increased with the increase in PCC-TCC distance (r = 0.25, p < 0.05). Conclusions The PCC-TCC distance has an important effect on patient pathways in subjects with suspected CAD. PMID:25489322

  16. Integrated assessment of biological invasions.

    PubMed

    Ibáñez, Ines; Diez, Jeffrey M; Miller, Luke P; Olden, Julian D; Sorte, Cascade J B; Blumenthal, Dana M; Bradley, Bethany A; D'Antonio, Carla M; Dukes, Jeffrey S; Early, Regan I; Grosholz, Edwin D; Lawler, Joshua J

    2014-01-01

    As the main witnesses of the ecological and economic impacts of invasions on ecosystems around the world, ecologists seek to provide the relevant science that informs managers about the potential for invasion of specific organisms in their region(s) of interest. Yet, the assorted literature that could inform such forecasts is rarely integrated to do so, and further, the diverse nature of the data available complicates synthesis and quantitative prediction. Here we present a set of analytical tools for synthesizing different levels of distributional and/or demographic data to produce meaningful assessments of invasion potential that can guide management at multiple phases of ongoing invasions, from dispersal to colonization to proliferation. We illustrate the utility of data-synthesis and data-model assimilation approaches with case studies of three well-known invasive species--a vine, a marine mussel, and a freshwater crayfish--under current and projected future climatic conditions. Results from the integrated assessments reflect the complexity of the invasion process and show that the most relevant climatic variables can have contrasting effects or operate at different intensities across habitat types. As a consequence, for two of the study species climate trends will increase the likelihood of invasion in some habitats and decrease it in others. Our results identified and quantified both bottlenecks and windows of opportunity for invasion, mainly related to the role of human uses of the landscape or to disruption of the flow of resources. The approach we describe has a high potential to enhance model realism, explanatory insight, and predictive capability, generating information that can inform management decisions and optimize phase-specific prevention and control efforts for a wide range of biological invasions.

  17. Neonatal invasive candidiasis.

    PubMed

    Stronati, M; Decembrino, L

    2006-12-01

    Over the last two decades, systemic fungal infections have emerged to play a primary role in hospital-acquired infections. C. albicans is involved in 75% of neonatal candidiasis; however, the incidence of infection from C. parapsilosis is also increasing significantly. The higher incidence observed in the high-risk group of very low birth weight (VLBW) infants is linked to their special physical characteristics and the diagnostic and therapeutic invasive procedures they undergo. Colonization is a relevant risk factor depending on the colonized site , the fungal species and the type of colonization. Serological tests have a low specificity and sensitivity; in many cases, they do not distinguish between colonization and infection. Blood culture, although the best diagnostic test for determining systemic infection, can result negative, even in cases of deep organ involvement. In addition, fungi grow more slowly than bacteria in cultures. So, the difficulty in diagnosing systemic candidiasis and its aspecific clinical features may make empirical therapy appropriate. Amphotericin B (AmB) alone or combined with 5-fluorocytosine remains the drug of choice. Fluconazole represents a valid alternative. Recently developed new formulations of amphotericin incapsulated in liposomes can avoid possible adverse effects. Prognosis depends on the specific micro-organism involved; mortality is higher in the presence of C. albicans. As prognosis is associated with high mortality, prevention measures to reduce risk factors are of critical importance.

  18. Wide-field optical coherence tomography angiography enabled by two repeated measurements of B-scans.

    PubMed

    Wang, Ruikang K; Zhang, Anqi; Choi, Woo June; Zhang, Qinqin; Chen, Chieh-Li; Miller, Andrew; Gregori, Giovanni; Rosenfeld, Philip J

    2016-05-15

    Optical coherence tomography angiography (OCTA) has increasingly become clinically important, particularly in ophthalmology. However, the field of view (FOV) for current OCTA imaging is severely limited due to A-scan rates that can be afforded by current clinical systems and, more importantly, the requirement of a repeated scanning protocol. This Letter evaluates the possibility of using only two repeated B-scans for OCTA for the purpose of an increased FOV. The effect of repeated numbers on the OCTA result is discussed through experiments on an animal model in vivo and evaluated using quantitative metrics for image quality. Demonstrated through in vivo imaging of a pathological human eye, we show that optical microangiography-based OCTA with two repeated B-scans can provide wide-field angiography up to 12×12  mm with clinically acceptable image quality.

  19. Bone suppression in CT angiography data by region-based multiresolution segmentation

    NASA Astrophysics Data System (ADS)

    Blaffert, Thomas; Wiemker, Rafael; Lin, Zhong Min

    2003-05-01

    Multi slice CT (MSCT) scanners have the advantage of high and isotropic image resolution, which broadens the range of examinations for CT angiography (CTA). A very important method to present the large amount of high-resolution 3D data is the visualization by maximum intensity projections (MIP). A problem with MIP projections in angiography is that bones often hide the vessels of interest, especially the scull and vertebral column. Software tools for a manual selection of bone regions and their suppression in the MIP are available, but processing is time-consuming and tedious. A highly computer-assisted of even fully automated suppression of bones would considerably speed up the examination and probably increase the number of examined cases. In this paper we investigate the suppression (or removal) of bone regions in 3D CT data sets for vascular examinations of the head with a visualization of the carotids and the circle of Willis.

  20. Advanced image processing for optical coherence tomographic angiography of macular diseases

    PubMed Central

    Zhang, Miao; Wang, Jie; Pechauer, Alex D.; Hwang, Thomas S.; Gao, Simon S.; Liu, Liang; Liu, Li; Bailey, Steven T.; Wilson, David J.; Huang, David; Jia, Yali

    2015-01-01

    This article provides an overview of advanced image processing for three dimensional (3D) optical coherence tomographic (OCT) angiography of macular diseases, including age-related macular degeneration (AMD) and diabetic retinopathy (DR). A fast automated retinal layers segmentation algorithm using directional graph search was introduced to separates 3D flow data into different layers in the presence of pathologies. Intelligent manual correction methods are also systematically addressed which can be done rapidly on a single frame and then automatically propagated to full 3D volume with accuracy better than 1 pixel. Methods to visualize and analyze the abnormalities including retinal and choroidal neovascularization, retinal ischemia, and macular edema were presented to facilitate the clinical use of OCT angiography. PMID:26713185

  1. Enhanced depth imaging OCT and indocyanine green angiography changes in acute macular neuroretinopathy.

    PubMed

    Sanjari, Nasrin; Moein, Hamid-Reza; Soheilian, Roham; Soheilian, Masoud; Peyman, Gholam A

    2013-01-01

    The authors describe indocyanine green angiography (ICGA) and enhanced depth imaging optical coherence tomography (EDI-OCT) in a 46-year-old male patient with acute macular neuroretinopathy (AMN). The chief complaint was decreasing visual acuity and metamorphopsia in both eyes of 1-month duration. Visual field assessment, fluorescein angiography, OCT, ICGA, and EDI-OCT were performed initially and at 3 months. ICGA showed choroidal vascular hyperpermeability and punctuate choroidal hyperfluorescent spots, especially in the left eye. EDI-OCT showed increased choroidal macular thickness, with inner and outer retinal layers affected. EDI-OCT and ICGA reveal that both the choroid and retina can be affected in AMN; however, the primary pathology and localization of depth of involvement in AMN remains unclear.

  2. Peripapillary circle of Zinn-Haller revealed by fundus fluorescein angiography

    PubMed Central

    Ko, M.; Kim, D.; Ahn, Y.

    1997-01-01

    AIMS—To observe the vascular pattern of the peripapillary circle of Zinn-Haller in humans by fundus fluorescein angiography.
METHODS—307 cases (from 212 patients) of fundus fluorescein angiograms performed in patients with myopic degeneration were evaluated to find the circle of Zinn-Haller and to observe its fundus fluorescein angiographic features.
RESULTS—15 cases (from 13 patients) with the circle of Zinn-Haller were found. It appeared as concentric or zigzag-shaped vascular fillings within the temporal crescent region. All cases were observed in pathological myopia with peripapillary atrophy and a tilted disc. Each arterial circle showed variations in location and shape.
CONCLUSIONS—The temporal part of the circle of Zinn-Haller can be revealed by fundus fluorescein angiography particularly in pathological eyes with prominent peripapillary atrophy and a tilted disc. The morphological variation of this arterial circle should be considered.

 PMID:9349154

  3. Evaluation of User Performance in Simulation-Based Diagnostic Cerebral Angiography Training.

    PubMed

    Zaika, Oleksiy; Nguyen, Ngan; Boulton, Mel; Eagleson, Roy; de Ribaupierre, Sandrine

    2016-01-01

    Simulation of anatomically complex procedures, such as angiography, is becoming more practical, however, computer-based modules require extensive research to assess their effectiveness. We organized two training schemas - alternating cases and consistent cases - and hypothesized that the alternating practice cases would be beneficial to test performance. Eight residents (4 radiology/4 neurosurgery) and 8 anatomy graduate students were trained on the Simbionix™ simulator in order to assess skill acquisition in diagnostic cerebral angiography over 8 sessions. We found that participants improve on total procedure time and total fluoroscopy time (p<0.05), but not on contrast injected or roadmaps created. There were no significant differences between alternating and consistent training types. Additional work needs to be done with higher sample numbers and visuospatial scores as criteria.

  4. Pitfalls in post-mortem CT-angiography--intravascular contrast induces post-mortem pericardial effusion.

    PubMed

    Berger, Nicole; Martinez, Rosita; Winklhofer, Sebastian; Flach, Patricia M; Ross, Steffen; Ampanozi, Garyfalia; Gascho, Dominic; Thali, Michael J; Ruder, Thomas D

    2013-11-01

    We present a case where multi-phase post-mortem computed tomography angiography (PMCTA) induced a hemorrhagic pericardial effusion during the venous phase of angiography. Post-mortem non-contrast CT (PMCT) suggested the presence of a ruptured aortic dissection. This diagnosis was confirmed by PMCTA after pressure controlled arterial injection of contrast. During the second phase of multi-phase PMCTA the presence of contrast leakage from the inferior cava vein into the pericardial sac was noted. Autopsy confirmed the post-mortem nature of this vascular tear. This case teaches us an important lesson: it underlines the necessity to critically analyze PMCT and PMCTA images in order to distinguish between artifacts, true pathologies and iatrogenic findings. In cases with ambiguous findings such as the case reported here, correlation of imaging findings with autopsy is elementary.

  5. Mandibular arteriovenous malformation: A rare life-threatening condition depicted on multidetector CT angiography

    PubMed Central

    Dwivedi, Amit Nandan Dhar; Pandey, Anubha; Kumar, Ishan; Agarwal, Arjit

    2014-01-01

    Arteriovenous malformation (AVM) of the mandible is a rare and potentially life-threatening condition which can lead to massive hemorrhage. The following is a description where a large mandibular AVM presented with torrential bleeding following tooth extraction for caries. An orthopantomogram (OPG) was performed which was suggestive of aneurysmal bone cyst or ameloblastoma. A computed tomography (CT) angiography revealed a large mandibular AVM with submandibular extension. It is important for both clinicians and radiologist to be aware of this type of lesion that can have life-threatening complications. It is important to define the anatomical location and the feeder vessels of the entity in detail preoperatively. This communication highlights the common differential and use of multidetector CT (MDCT) angiography along with other imaging modalities to prevent a fatal hemorrhage and arrive at a correct diagnosis. PMID:24959049

  6. [Comparative study of results of coronary angiography in patients with first and repetitive myocardial infarction].

    PubMed

    Boldyreva, M O

    2013-01-01

    We compared coronary angiography data from 65 patients with first myocardial infarction (fMI) and 65 patients with repetitive MI (reMI). Coronary angiographic status in both patients with fMI and reMI was characterized by predominance of multivessel lesions with stenoses localized in branches of both coronary arteries (CA). Contrary to fMI patients with reMI had more severe right CA involvement, greater number of occlusions and diffuse lesions in CA bed. Differences between angiography data between fMI and reMI were more pronounced in men than in women. Angiographic differences between fMI and reMI did not depend on the presence of history of arterial hypertension and were considerably attenuated by diabetes mellitus.

  7. The Digital Angiography Reading Center (DARC) role in the anecortave acetate clinical trials.

    PubMed

    Slakter, Jason S; Carvalho, Cynthia; Coleman, Hannah

    2007-01-01

    Advances in digital camera and computer technology have resulted in imaging systems providing clinically relevant information equivalent to traditional film-based techniques. The Digital Angiography Reading Center (DARC) was created to provide the next generation in reading center assessment for clinical trials of retinal disease. A fully digital angiographic imaging protocol was implemented with the anecortave acetate clinical studies. For image evaluation readers followed a standard manual of definitions and guidelines. Eligibility was determined based on protocol specific criteria. Rapid communication of images between the study sites and DARC permitted screening for eligibility and pre-treatment stratification of all patients prior to enrollment. This screening process was designed to eliminate angiographically ineligible patients from the clinical trials. The result was a reduction in the total number of patients needed to obtain sufficient evaluable patients for statistical assessment of treatment outcome. Digital angiography can be successfully used in clinical trials for retinal disease.

  8. Evaluation of measures of technical image quality for intracranial magnetic resonance angiography.

    PubMed

    Chapman, B E; Goodrich, C K; Alexander, A L; Blatter, D D; Parker, D L

    1999-12-01

    We evaluate three measures of technical image quality for intracranial magnetic resonance angiography (MRA): (1) a two-alternative forced choice (2AFC) evaluation of vessel visibility, (2) vessel-to-background signal-difference-to-noise ratio (SDNR), and (3) observer ranking of the fidelity of vessel morphology compared to that in a gold standard image. The gold standard used for both the 2AFC and ranking measures is intraarterial catheter angiography. These measures are applied to healthy arterial segments. The 2AFC and SDNR measures directly evaluate the visibility of artery segments for which the existence is known from the gold standard images. We argue that (1) 2AFC evaluates the carrier signals on which any vascular disease process is modulated and provides an upper bound on the detectibility of vascular lesions, (2) SDNR is a predictor of 2AFC, and (3) ranking may be used to predict the relative performance of techniques in the detection of vascular lesions.

  9. Computed tomography angiography in acute stroke (revisiting the 4Ps of imaging).

    PubMed

    Varadharajan, Shriram; Saini, Jitender; Acharya, Ullas V; Gupta, Arun Kumar

    2016-02-01

    Imaging in acute stroke has traditionally focussed on the 4Ps-parenchyma, pipes, perfusion, and penumbra-and has increasingly relied upon advanced techniques including magnetic resonance imaging to evaluate such patients. However, as per European Magnetic Resonance Forum estimates, the availability of magnetic resonance imaging scanners for the general population in India (0.5 per million inhabitants) is quite low as compared to Europe (11 per million) and United States (35 per million), with most of them only present in urban cities. On the other hand, computed tomography (CT) is more widely available and has reduced scanning duration. Computed tomography angiography of cervical and intracranial vessels is relatively simpler to perform with extended coverage and can provide all pertinent information required in such patients. This imaging review will discuss relevant imaging findings on CT angiography in patients with acute ischemic stroke through illustrated cases.

  10. Posttraumatic splenic pseudoaneurysm and arteriovenous fistula: diagnosis by computed tomography angiography and treatment by transcatheter embolization.

    PubMed

    Oguz, Berna; Cil, Barbaros; Ekinci, Saniye; Karnak, Ibrahim; Akata, Deniz; Haliloglu, Mithat

    2005-12-01

    The current treatment of splenic injury in children is conservative. The common concern with nonoperative management of splenic injury involves increased risk of posttraumatic splenic complications. Computed tomography angiography is a noninvasive and useful technique for the detection of the vascular abnormalities in conservatively managed splenic injuries. We present a case of posttraumatic splenic pseudoaneurysm and arteriovenous fistula (AVF) in a 12-year-old boy, which were prediagnosed by color Doppler ultrasound and consecutively shown by computed tomography angiography. The treatment of splenic AVF is indicated to avoid portal hypertension, high output cardiac failure, and related complications. To preserve the splenic immune function and to avoid the risk of surgery and splenectomy complications, splenic pseudoaneurysm and AVF were successfully occluded by transcatheter embolization.

  11. Exotic sources of x-rays for iodine K-edge angiography

    SciTech Connect

    Carr, R.

    1993-08-01

    Digital Subtractive Angiography (DSA) has been performed to image human coronary arteries using wiggler radiation from electron storage rings. The significant medical promise of this procedure motivates the development of smaller and less costly x-ray sources. Several exotic sources are candidates for consideration, using effects such as Cherenkov, channeling, coherent bremsstrahlung, laser backscattering, microundulator, parametric, Smith-Purcell, and transition radiation. In this work we present an analysis of these effects as possible sources of intense x-rays at the iodine K-edge at 33.169 key. The criteria we use are energy, efficiency, flux, optical properties, and technical realizability. For each of the techniques, we find that they suffer either from low flux, a low energy cutoff, target materials heating, too high electron beam energy requirement, optical mismatch to angiography, or a combination of these. We conclude that the foreseeable state-of-the-art favors a compact storage ring design.

  12. Contrast agents for cardiac angiography: effects of a nonionic agent vs. a standard ionic agent

    SciTech Connect

    Bettmann, M.A.; Bourdillon, P.D.; Barry, W.H.; Brush, K.A.; Levin, D.C.

    1984-12-01

    The effects on cardiac hemodynamics and of a standard contrast agent, sodium methylglucamine diatrizoate (Renografin 76) were compared with the effects of a new nonionic agent (iohexol) in a double-blind study in 51 patietns undergoing coronary angiography and left ventriculography. No significant alteration in measured blood parameters occurred with either contrast agent. Hemodynamic changes occurred with both, but were significantly greater with the standard renografin than with the low-osmolality, nonionic iohexol. After left ventriculography, heart rate increased and peripheral arterial pressure fell with both agents, but less with iohexol. It is concluded that iohexol causes less alteration in cardiac function than does the agent currently most widely used. Nonionic contrast material is likely to improve the safety of coronary angiography, particularly in those patients at greatest risk.

  13. Confirmation of brain death with portable isotope angiography: a review of 204 consecutive cases

    SciTech Connect

    Goodman, J.M.; Heck, L.L.; Moore, B.D.

    1985-04-01

    Intravenous isotope angiography is a rapid, safe, and specific bedside test for confirming brain death by demonstrating the lack of critical cerebral perfusion that occurs in this condition, regardless of etiology. A review of 204 consecutive cases of suspected brain death studied with isotope angiography has reaffirmed our confidence in the specificity of the technique and has convinced us to make less stringent our radiographic criteria for confirming brain death by this method. A technically satisfactory single flow study that shows arrest of the carotid circulation at the base of the skull and absence of the intracranial arterial circulation may be considered confirmatory of a carefully established clinical diagnosis of brain death, even though there may be some visualization of the intracranial venous sinuses. Arbitrary waiting periods, withdrawal of sedative drugs, and electrophysiological studies are not needed when this technique is used.

  14. Optical Coherence Tomography and Optical Coherence Tomography Angiography in Monitoring Coats' Disease

    PubMed Central

    Hautz, Wojciech; Kocyła-Karczmarewicz, Beata

    2017-01-01

    Purpose. The aim of this study was to evaluate the usefulness of optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in monitoring pediatric patients with Coats' disease. Material and Methods. This retrospective study included 9 Caucasian patients receiving treatment for Coats' disease at the Children's Memorial Health Institute Ophthalmology Department between December 2014 and May 2016. The course of the disease was monitored with OCTA in combination with OCT and fluorescein angiography (FA). Results. OCT B-scans obtained in all patients correlated with FA findings. Reliable OCTA images were obtained in 8 patients. In one patient, numerous artifacts due to poor visual acuity and retinal detachment confounded the interpretation of findings. Conclusions. OCTA and OCT, in combination with FA, are useful in Coats' disease diagnostics and treatment monitoring. As noninvasive methods, OCT and OCTA may be performed more often than FA, which enable precise monitoring of the disease and making decisions as to its further treatment. PMID:28377823

  15. Non-invasive hemoglobin monitoring.

    PubMed

    Joseph, Bellal; Haider, Ansab; Rhee, Peter

    2016-09-01

    Technology has transformed the practice of medicine and surgery in particular over the last several decades. This change in practice has allowed diagnostic and therapeutic tests to be performed less invasively. Hemoglobin monitoring remains one of the most commonly performed diagnostic tests in the United States. Recently, non-invasive hemoglobin monitoring technology has gained popularity. The aim of this article is to review the principles of how this technology works, pros and cons, and the implications of non-invasive hemoglobin technology particularly in trauma surgery.

  16. Detection of Type II Endoleak After Endovascular Aortic Repair: Comparison Between Magnetic Resonance Angiography and Blood-Pool Contrast Agent and Dual-Phase Computed Tomography Angiography

    SciTech Connect

    Wieners, Gero; Meyer, Frank; Halloul, Zuhir; Peters, Nils; Ruehl, Ricarda; Dudeck, Oliver; Tautenhahn, Joerg; Ricke, Jens; Pech, Maciej

    2010-12-15

    PurposeThis prospective study was designed to assess the diagnostic value of magnetic resonance angiography (MRA) with blood-pool contrast agent (gadofosveset) in the detection of type-II endoleak after endovascular aortic repair (EVAR).MethodsThirty-two patients with aortic aneurysms who had undergone EVAR were included in this study. All patients were examined by dual-phase computed tomography angiography (CTA) as well as MRA with gadofosveset in the first-pass and steady-state phases. Two independent readers evaluated the images of CTA and MRA in terms of endoleak type II, feeding vessel, and image quality.ResultsMedian follow-up-time after EVAR was 22 months (range 4 to 59). Endoleak type II was detected by CTA in 12 of 32 patients (37.5%); MRA detected endoleak in all of these patients as well as in another 9 patients (n = 21, 65.6%), of whom the endoleaks in 6 patients showed an increasing diameter. Most endoleaks were detected in the steady-state phase (n = 14). The decrease in diameter of the aneurysmal sac was significantly greater in the patients without a visible endoleak that was visible on MRA (P = 0.004). In the overall estimation of diagnostic accuracy, MRA was judged superior to CTA in 66% of all examinations.ConclusionMRA with gadofosveset appeared superior to CTA, and has higher diagnostic accuracy, in the detection of endoleak after EVAR.

  17. Aqueous Angiography: Real-Time and Physiologic Aqueous Humor Outflow Imaging

    PubMed Central

    Saraswathy, Sindhu; Tan, James C. H.; Yu, Fei; Francis, Brian A.; Hinton, David R.; Weinreb, Robert N.; Huang, Alex S.

    2016-01-01

    Purpose Trabecular meshwork (TM) bypass surgeries attempt to enhance aqueous humor outflow (AHO) to lower intraocular pressure (IOP). While TM bypass results are promising, inconsistent success is seen. One hypothesis for this variability rests upon segmental (non-360 degrees uniform) AHO. We describe aqueous angiography as a real-time and physiologic AHO imaging technique in model eyes as a way to simulate live AHO imaging. Methods Pig (n = 46) and human (n = 6) enucleated eyes were obtained, orientated based upon inferior oblique insertion, and pre-perfused with balanced salt solution via a Lewicky AC maintainer through a 1mm side-port. Fluorescein (2.5%) was introduced intracamerally at 10 or 30 mm Hg. With an angiographer, infrared and fluorescent (486 nm) images were acquired. Image processing allowed for collection of pixel information based on intensity or location for statistical analyses. Concurrent OCT was performed, and fixable fluorescent dextrans were introduced into the eye for histological analysis of angiographically active areas. Results Aqueous angiography yielded high quality images with segmental patterns (p<0.0001; Kruskal-Wallis test). No single quadrant was consistently identified as the primary quadrant of angiographic signal (p = 0.06–0.86; Kruskal-Wallis test). Regions of high proximal signal did not necessarily correlate with regions of high distal signal. Angiographically positive but not negative areas demonstrated intrascleral lumens on OCT images. Aqueous angiography with fluorescent dextrans led to their trapping in AHO pathways. Conclusions Aqueous angiography is a real-time and physiologic AHO imaging technique in model eyes. PMID:26807586

  18. Transradial approach for coronary angiography and interventions in patients with coronary bypass grafts: tips and tricks.

    PubMed

    Burzotta, Francesco; Trani, Carlo; Hamon, Martial; Amoroso, Giovanni; Kiemeneij, Ferdinand

    2008-08-01

    Among patients undergoing coronary procedures, patients with coronary artery bypass grafts represent an important, high risk subgroup. Routine transradial approach may be successfully adopted in these patients to reduce access-site complications. However, transradial cannulation of the grafts may result technically demanding. In this article we discuss the specific technical issues and we present a series of tips and tricks which may facilitate angiography and interventions on both internal mammary and aorto-coronary grafts.

  19. Unusual Malignant Coronary Artery Anomaly: Results of Coronary Angiography, MR Imaging, and Multislice CT

    SciTech Connect

    Apitzsch, Jonas; Kuehl, Harald P.; Muehlenbruch, Georg; Mahnken, Andreas H.

    2010-04-15

    We report the case of a man with an uncommon anomaly of the origin and course of the left coronary artery. Clinical, coronary angiography, magnetic resonance imaging, and multislice computed tomography findings of this intermittently symptomatic 49 year-old patient with the rare anomaly of his left coronary artery stemming from the right sinus of Valsalva and taking an interarterial and intraseptal course are presented. The diagnostic value of the different imaging modalities is discussed.

  20. Three-dimensional CT angiography: a new technique for imaging microvascular anatomy.

    PubMed

    Tregaskiss, Ashley P; Goodwin, Adam N; Bright, Linda D; Ziegler, Craig H; Acland, Robert D

    2007-03-01

    To date there has been no satisfactory research method for imaging microvascular anatomy in three dimensions (3D). In this article we present a new technique that allows both qualitative and quantitative examination of the microvasculature in 3D. In 10 fresh cadavers (7 females, 3 males, mean age 68 years), selected arteries supplying the abdominal wall and back were injected with a lead oxide/gelatin contrast mixture. From these regions, 30 specimens were dissected free and imaged with a 16-slice spiral computed tomographic (CT) scanner. Using three-dimensional CT (3D-CT) angiography, reconstructions of the microvasculature of each specimen were produced and examined for their qualitative content. Two calibration tools were constructed to determine (1) the accuracy of linear measurements made with CT software tools, and (2) the smallest caliber blood vessel that is reliably represented on 3D-CT reconstructions. Three-dimensional CT angiography produced versatile, high quality angiograms of the microvasculature. Correlation between measurements made with electronic calipers and CT software tools was very high (Lin's concordance coefficient, 0.99 (95% CI 0.99-0.99)). The finest caliber of vessel reliably represented on the 3D-CT reconstructions was 0.4 mm internal diameter. In summary, 3D-CT angiography is a simple, accurate, and reproducible method that imparts a much improved perception of anatomy when compared with existing research methods. Measurement tools provide accurate quantitative data to aid vessel mapping and preoperative planning. Further work will be needed to explore the full utility of 3D-CT angiography in a clinical setting.

  1. Quantitative Spatial and Temporal Analysis of Fluorescein Angiography Dynamics in the Eye

    PubMed Central

    Hui, Flora; Nguyen, Christine T. O.; Bedggood, Phillip A.; He, Zheng; Fish, Rebecca L.; Gurrell, Rachel; Vingrys, Algis J.; Bui, Bang V.

    2014-01-01

    Purpose We describe a novel approach to analyze fluorescein angiography to investigate fluorescein flow dynamics in the rat posterior retina as well as identify abnormal areas following laser photocoagulation. Methods Experiments were undertaken in adult Long Evans rats. Using a rodent retinal camera, videos were acquired at 30 frames per second for 30 seconds following intravenous introduction of sodium fluorescein in a group of control animals (n = 14). Videos were image registered and analyzed using principle components analysis across all pixels in the field. This returns fluorescence intensity profiles from which, the half-rise (time to 50% brightness), half-fall (time for 50% decay) back to an offset (plateau level of fluorescence). We applied this analysis to video fluorescein angiography data collected 30 minutes following laser photocoagulation in a separate group of rats (n = 7). Results Pixel-by-pixel analysis of video angiography clearly delineates differences in the temporal profiles of arteries, veins and capillaries in the posterior retina. We find no difference in half-rise, half-fall or offset amongst the four quadrants (inferior, nasal, superior, temporal). We also found little difference with eccentricity. By expressing the parameters at each pixel as a function of the number of standard deviation from the average of the entire field, we could clearly identify the spatial extent of the laser injury. Conclusions This simple registration and analysis provides a way to monitor the size of vascular injury, to highlight areas of subtle vascular leakage and to quantify vascular dynamics not possible using current fluorescein angiography approaches. This can be applied in both laboratory and clinical settings for in vivo dynamic fluorescent imaging of vasculature. PMID:25365578

  2. Aviation Epidemiology Data Register: Coronary Angiography Outcomes of Civilian Aviators Flying U.S. Aircraft

    DTIC Science & Technology

    1994-08-01

    All Army aviators participate in a cardiovascular disease screening program. Five percent of Army aviators are civilian. The U.S. Army Aviation...Center requested a review of cardiovascular disease screening outcomes among this subgroup of aviators. The AEDR was queried to determine the coronary...angiography outcomes of civilian aviators who failed levels 1 and 2 of cardiovascular disease screening program during the period 1988 to 1992. Among 847

  3. Intravascular detection of microvessel infiltration in atherosclerotic plaques: An intraluminal extension of acoustic angiography

    NASA Astrophysics Data System (ADS)

    Martin, K. Heath

    Cardiovascular disease is the leading cause of death worldwide, surpassing both stroke and cancer related mortality with 17.5 million deaths in 2014 alone. Atherosclerosis is the build-up of fatty deposits within arteries and is responsible for the majority of cardiovascular related deaths. Over the past decade, research in atherosclerosis has identified that a key limitation in the appropriate management of the disease is detecting and identifying dangerous fatty plaque build-ups before they dislodge and cause major cardiovascular events, such as embolisms, stroke, or myocardial infarctions. It has been noted that plaques vulnerable to rupture have several key features that may be used to distinguish them from asymptomatic plaques. One key identifier of a dangerous plaque is the presence of blood flow within the plaque itself since this is an indicator of growth and instability of the plaque. Recently, a superharmonic imaging method known as "acoustic angiography" has been shown to resolve microvasculature with unprecedented quality and could be a possible method of detecting blood vessel infiltration within these plaques. This dissertation describes the material and methods used to move the application of "acoustic angiography" to a reduced form factor typical of intravascular catheters and to demonstrate its ability to detect microvasculature. The implementation of this approach is described in terms of the contrast agents used to generate superharmonic signals, the dual-frequency transducers to image them, and the hardware needed to operate them in order to establish how these design choices can impact the quality of the images produced. Furthermore, this dissertation demonstrates how image processing methods such as adaptive windowing or automated sound speed correction can further enhance image quality of vascular targets. The results of these chapters show how acoustic angiography may be optimized using engineering considerations both in signal acquisition

  4. Aneurysm of the proximal thoracic aorta simulating neoplasm: the role of CT and angiography

    SciTech Connect

    Smith, T.R.; Khoury, P.T.

    1985-05-01

    Ascending aortic and proximal transverse arch aneurysms may sometimes project to the left of midline and be difficult to distinguish from neoplasm. The authors have recently encountered three such cases that presented as possible neoplastic soft-tissue masses overlying the left upper lobe. They did not enhance on intravenous-contrast-enhanced CT scans, and in two cases the diagnosis of aneurysm was not confirmed until angiography was performed.

  5. Four- and Eight-Channel Aortoiliac CT Angiography: A Comparative Study

    SciTech Connect

    Karcaaltincaba, Musturay Foley, Dennis

    2005-04-15

    Purpose. To compare performance parameters, contrast material load and radiation dose in a patient cohort having aortoiliac CT angiography using 4- and 8-channel multidetector CT (MDCT) systems. Methods. Eighteen patients with abdominal aortic aneurysms underwent initial 4-channel and follow-up 8-channel MDCT angiography. Both the 4- and 8-channel MDCT systems utilized a matrix detector of 16 x 1.25 mm rows. Scan coverage included the abdominal aorta and iliac arteries to the level of the proximal femoral arteries. For 4-channel MDCT, nominal slice thickness and beam pitch were 1.25 mm and 1.5, respectively, and for 8-channel MDCT they were 1.25 mm and 1.35 or 1.65 respectively. Scan duration, iodinated contrast material load and mean aortoiliac attenuation were compared retrospectively. Comparative radiation dose measurements for 4- and 8-channel MDCT were obtained using a multiple scan average dose technique on an abdominal phantom. Results. Compared with 4-channel MDCT, 8-channel MDCT aortoiliac angiography was performed with equivalent collimation, decreased contrast load (mean 45% decrease: 144 ml versus 83 ml of 300 mg iodine/ml contrast material) and decreased acquisition time (mean 51% shorter: 34.4 sec versus 16.9 sec) without a significant change in mean aortic enhancement (299 HU versus 300 HU, p > 0.05). Radiation dose was 2 rad for the 4-channel system and 2/1.5 rad for the 8-channel system at 1.35/1.65 pitch respectively. Conclusion. Compared with 4-channel MDCT, aortoiliac CT angiography with 8-channel MDCT produces equivalent z-axis resolution with decreased contrast load and acquisition time without increased radiation exposure.

  6. Clinical application of a light-pen computer system for quantitative angiography

    NASA Technical Reports Server (NTRS)

    Alderman, E. L.

    1975-01-01

    The important features in a clinical system for quantitative angiography were examined. The human interface for data input, whether an electrostatic pen, sonic pen, or light-pen must be engineered to optimize the quality of margin definition. The computer programs which the technician uses for data entry and computation of ventriculographic measurements must be convenient to use on a routine basis in a laboratory performing multiple studies per day. The method used for magnification correction must be continuously monitored.

  7. Acetylcholine test in patients with angina pectoris and normal coronary angiography

    NASA Astrophysics Data System (ADS)

    Barbieri, Enrico; Destro, Gianni; Oliva, Massimo; Zardini, Piero

    1994-02-01

    Angina pectoris with normal coronary artery on the coronary angiography is an intriguing issue. Intracoronary infusion of acetylcholine has recently been used to test the integrity of endothelial cells. We studied 16 patients with this syndrome. A relationship has been found between the acetylcholine test and the exercise stress test in normotensive patients. The presence of hypertension makes the evaluation of the test more unpredictable, probably because of the damage on the endothelial cells related to systemic hypertension.

  8. Radiologic Damage Control: Evaluation of a Combined CT and Angiography Suite with a Pivoting Table

    SciTech Connect

    Kos, Xavier; Fanchamps, Jean-Marc; Trotteur, Genevieve; Dondelinger, Robert F.

    1999-03-15

    Purpose: To evaluate retrospectively the integrated diagnostic and therapeutic management of severely polytraumatized patients using a combined computed tomography (CT) and angiography suite with a single pivoting table. Methods: Eleven patients, aged 16-74 years (median 30 years), were managed with spiral CT and angiography without patient transfer. Four patients were unstable, seven had received blood transfusions (2-18 units) and six were intubated. In 10 patients in whom active bleeding was demonstrated (splenic 5, hepatic 2, renal 2, left inferior epigastric artery 1), hemostatic embolization was obtained. Results: Total procedure time did not exceed 80 min. Immediate hemostasis was achieved in all patients. Recurrent bleeding from the liver required additional embolization in one patient. Median length of stay in the intensive care unit was 4 days and median hospital stay was 27 days. All patients survived without significant sequelae. Conclusion: The use of a combined CT-angiography suite enables rapid diagnostic investigation and hemostatic embolization in actively bleeding trauma patients.

  9. Randomized comparison of transradial coronary angiography via right or left radial artery approaches.

    PubMed

    Kanei, Yumiko; Nakra, Navin C; Liou, Michael; Vales, Lori L; Gowda, Ramesh; Rosero, Hugo; Kwan, Tak; Fox, John T

    2011-01-15

    Previous studies have shown that the right radial approach encounters more tortuosity than the left radial approach during transradial coronary angiography. The objective of this study was to compare the procedural difficulty of the right and left radial approaches in the modern era with dedicated transradial catheters. One hundred ninety-three patients scheduled for transradial coronary angiography with normal Allen test results and without histories of coronary artery bypass grafting were randomized to the right or left radial approach. The choice of catheter was left to the discretion of the operator, with the preferred catheter being a dedicated transradial Optitorque catheter. The primary end point was procedural difficulty, defined as (1) hydrophilic or coronary wire use for tortuosity, (2) stiff wire use for the coronary engagement, (3) multiple catheters used, or (4) nonselective injection. The clinical characteristics were similar between the 2 groups. Procedural success was achieved in 98 of 101 (98%) in the right radial group and 91 of 92 (99%) in the left radial group. Procedural difficulty, fluoroscopy time, and contrast use were similar between the 2 groups. The use of a single catheter was more common in the right radial group (73% vs 18%, p <0.001). In conclusion, procedural success and difficulty were similar in the comparison groups. The right and left radial approaches are feasible and effective to perform coronary angiography and intervention.

  10. Demonstration of enhanced K-edge angiography using a cerium target x-ray generator

    SciTech Connect

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2004-11-01

    The cerium target x-ray generator is useful in order to perform enhanced K-edge angiography using a cone beam because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast mediums. The x-ray generator consists of a main controller, a unit with a Cockcroft-Walton circuit and a fixed anode x-ray tube, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.0x1.3 mm. Cerium K{alpha} lines were left using a barium sulfate filter, and the x-ray intensity was 0.48 {mu}C/kg at 1.0 m from the source with a tube voltage of 60 kV, a current of 0.40 mA, and an exposure time of 1.0 s. Angiography was performed with a computed radiography system using iodine-based microspheres. In coronary angiography of nonliving animals, we observed fine blood vessels of approximately 100 {mu}m with high contrasts.

  11. Compact x-ray generator utilizing cerium-target tube for angiography

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ito, Fumihito; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2004-11-01

    The cerium-target x-ray tube is useful in order to perform cone beam K-edge angiography because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast mediums. The x-ray generator consists of a main controller and a unit with a high-voltage circuit and a fixed anode x-ray tube. The tube is a glass-enclosed diode with a cerium target and a 0.5 mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.3×0.9 mm. Cerium K-series characteristic x rays were left using a 3.0 mm-thick aluminum filter, and the x-ray intensity was 0.59 μC/kg at 1.0 m from the source with a tube voltage of 60 kV, a current of 0.40 mA, and an exposure time of 1.0 s. Angiography was performed with a computed radiography system using iodine-based microspheres 15 μm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 μm with high contrasts.

  12. [Dissecting aneurysm of the posterior inferior cerebellar artery--studied by serial angiography].

    PubMed

    Yamashita, Y; Hayashi, S; Saitho, H; Teramoto, A

    2001-11-01

    We report the case of a 34-year-old male with cerebellar hemorrhagic infarction caused by a dissecting aneurysm of the left posterior inferior cerebellar artery (PICA). The patient suffered from a headache and vomiting for two days and was transferred to our hospital with sudden deterioration of consciousness. On admission, he was semicomatose. A CT scan revealed hemorrhagic infarction in the left cerebellum and upward herniation. The emergency operation for posterior fossa decompression was performed. Postoperatively, his consciousness level improved promptly and he had no neurological deficits except for slight gait disturbance. The first vertebral angiography was performed on Day 27. It showed a sausage-like dissecting aneurysm of the left distal PICA. We planned conservative therapy with careful observation because of there being no indication for an operation. Serial angiography was performed and demonstrated the regression of the dissecting aneurysm on Day 258. Dissecting aneurysms of the distal PICA are rare and their natural history is not well understood. Conservative therapy for vertebrobasilar dissecting aneurysms has often been reported. We suggest that conservative therapy with serial angiography is the treatment of choice especially for ischemic-type dissecting aneurysms. We review 17 cases of dissecting aneurysm of the distal PICA in this study.

  13. The Frequency and Significance of Silent Myocardial Ischemia Due to Hyoscine Butylbromide Use in Peripheral Angiography

    SciTech Connect

    Maher, Richard; Phillips-Hughes, Jane; Banning, Adrian; Boardman, Philip

    1999-09-15

    Purpose: Hyoscine-N-butylbromide (HB) is an anticholinergic drug used in digital subtraction angiography of the aortoiliac region because it decreases bowel gas movement artifact. HB also causes an increase in heart rate. We investigated whether this could cause silent myocardial ischemia (SMI) in susceptible patients during peripheral angiography. Methods: Thirty-six patients undergoing peripheral angiography were randomized into two groups, with 17 patients receiving 20 mg HB intraarterially during the angiogram and 19 patients receiving no drug. All patients were fitted with a Holter monitor that recorded the electrocardiogram before, during, and after the angiogram. Heart rate trends and ST segments were then analyzed. Results: Patients given HB had a statistically significant rise in heart rate compared with the control group. Although the difference was not statistically significant, two (12%) patients receiving HB had procedural ST depression compared with none in the control group. Pre- and postprocedural episodes of ST depression were common, occurring in 41% of patients receiving HB and 37% of patients receiving no drug, and were associated with an increase in heart rate. Conclusion: The infrequent episodes of procedural SMI, potentially caused by the positive chronotropic effects of HB, are probably insignificant when compared with the high frequency of SMI episodes occurring outside the procedure.

  14. Scalable wide-field optical coherence tomography-based angiography for in vivo imaging applications

    PubMed Central

    Xu, Jingjiang; Wei, Wei; Song, Shaozhen; Qi, Xiaoli; Wang, Ruikang K.

    2016-01-01

    Recent advances in optical coherence tomography (OCT)-based angiography have demonstrated a variety of biomedical applications in the diagnosis and therapeutic monitoring of diseases with vascular involvement. While promising, its imaging field of view (FOV) is however still limited (typically less than 9 mm2), which somehow slows down its clinical acceptance. In this paper, we report a high-speed spectral-domain OCT operating at 1310 nm to enable wide FOV up to 750 mm2. Using optical microangiography (OMAG) algorithm, we are able to map vascular networks within living biological tissues. Thanks to 2,048 pixel-array line scan InGaAs camera operating at 147 kHz scan rate, the system delivers a ranging depth of ~7.5 mm and provides wide-field OCT-based angiography at a single data acquisition. We implement two imaging modes (i.e., wide-field mode and high-resolution mode) in the OCT system, which gives highly scalable FOV with flexible lateral resolution. We demonstrate scalable wide-field vascular imaging for multiple finger nail beds in human and whole brain in mice with skull left intact at a single 3D scan, promising new opportunities for wide-field OCT-based angiography for many clinical applications. PMID:27231630

  15. Optical coherence tomography angiography in eyes with good visual acuity recovery after treatment for optic neuritis

    PubMed Central

    Higashiyama, Tomoaki; Nishida, Yasuhiro; Ohji, Masahito

    2017-01-01

    Objective To evaluate the retinal perfusion using optical coherence tomography (OCT) angiography in eyes with good visual acuity recovery after treatment for optic neuritis (ON). Methods Seven eyes of seven patients with good visual acuity recovery after treatment for monocular ON and seven eyes of each fellow eye used as controls were studied. Retinal perfusion around the disc and at the macula was evaluated using OCT angiography. The retinal nerve fiber layer thickness was measured around the disc. The ganglion cell layer complex thickness or the ganglion cell layer plus the inner plexiform layer thickness were measured at the macula. Results The retinal perfusions in all eyes with ON decreased around the disc and at the macula compared with those of the fellow eyes, as shown by OCT angiography (disc, P = 0.003; macula, P = 0.001). The retinal thicknesses in all eyes with ON also decreased around the disc and at the macula compared with those of the fellow eyes (disc, P < 0.001; macula, P = 0.003). Conclusions Optic neuritis may cause not only retinal structural damage but also decreased retinal perfusion, even after the visual acuity recovered well after treatment. PMID:28192497

  16. A case of acute subdural hematoma due to ruptured aneurysm detected by postmortem angiography.

    PubMed

    Inokuchi, Go; Makino, Yohsuke; Yajima, Daisuke; Motomura, Ayumi; Chiba, Fumiko; Torimitsu, Suguru; Hoshioka, Yumi; Iwase, Hirotaro

    2016-03-01

    Acute subdural hematoma (ASDH) is mostly caused by head trauma, but intrinsic causes also exist such as aneurysm rupture. We describe here a case involving a man in his 70s who was found lying on the bedroom floor by his family. CT performed at the hospital showed ASDH and a forensic autopsy was requested. Postmortem cerebral angiography showed dilatation of the bifurcation of the middle cerebral artery, which coincided with the dilated part of the Sylvian fissure. Extravasation of contrast medium into the subdural hematoma from this site was suggestive of a ruptured aneurysm. Autopsy revealed a fleshy hematoma (total weight 110 g) in the right subdural space and findings of brain herniation. As indicated on angiography, a ruptured saccular aneurysm was confirmed at the bifurcation of the middle cerebral artery. Obvious injuries to the head or face could not be detected on either external or internal examination, and intrinsic ASDH due to a ruptured middle cerebral artery aneurysm was determined as the cause of death. One of the key points of forensic diagnosis is the strict differentiation between intrinsic and extrinsic onset for conditions leading to death. Although most subdural hematomas (SDH) are caused by extrinsic factors, forensic pathologists should consider the possibility of intrinsic SDH. In addition, postmortem angiography can be useful for identifying vascular lesions in such cases.

  17. Intracranial aneurysms: Diagnostics accuracy of three-dimensional, fourier transform, time-of-flight MR angiography

    SciTech Connect

    Korogi, Yukunori; Takahashi, Mutsumasa; Mabuchi, Nobuhisa; Miki, Hitoshi; Fujiwara, Satoru; Horikawa, Yoshiharu; Nakagawa, Toshio; O`Uchi, Toshihiro; Watabe, Tsuneya; Shiga, Hayao

    1994-10-01

    To assess the accuracy of three-dimensional, Fourier transform, time-of-flight magnetic resonance (MR) angiography in the identification of intracranial aneurysms. MR angiograms of 126 patients (59 male and 67 female patients, aged 12-77 years) with various intracranial vascular lesions were evaluated. Seventy-eight aneurysms, including 60 less than 5 mm in diameter, in 61 patients were depicted at conventional angiography. Eight projection images, as well as one axial collapsed MR angiogram obtained with a maximum-intensity projection algorithm, were used for evaluation. Sensitivity for the five observers ranged from 58% to 68% (mean, 63%). Higher sensitivity was achieved for anterior communicating and middle cerebral artery aneurysms, while that for internal carotid artery aneurysms was poor. Sensitivities for small and medium aneurysms ranged from 50% to 60% (mean, 56%) and from 77% to 94% (mean, 85%), respectively. MR angiography can depict intracranial aneurysms 5 mm or larger with good accuracy but is less useful for the identification of smaller aneurysms. 12 refs., 5 figs., 5 tabs.

  18. Cheatgrass invasion and wildlife habitat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The introduction and subsequent invasion of cheatgrass (Bromus tectorum) has altered native plant communities and the wildlife species that depend on these communities. Cheatgrass has truncated secondary succession by outcompeting native plant species for limited resources, thus building persistent...

  19. Non-invasive diagnosis and continuous monitoring of thrombosis in clinics by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Ting; Sun, Yunglong; Chen, Xiao; Zhao, Yue; Ren, Rongrong; Liu, Mushuang

    2015-03-01

    Thrombosis became one of the most severe disease hazard to human health, and it incidence rate grows increasingly higher throughout the world. The conventional diagnosis and monitoring thrombosis mainly relied on the invasive techniques, e.g., digital subtraction angiography and blood sample analysis, and expensive and ionizing techniques, e.g., magnetic resonance angiography. And those techniques can not measure continuously. Here we reported our preliminary exploration of using near-infrared spectroscopy (NIRS) in clinical monitoring of thrombosis. 7 healthy subjects and 6 thrombosis patients at similar age participated the NIRS measurements of oxy- and deoxy- hemoglobin ([HbO2] and [Hb]) on 6 particular parts of legs. We repeated [HbO2] measurement at the same specified time each day after thrombolytic therapy for one single-leg-DVT patient, and terminated till the patient was cured and left hospital. We found that - (1) [HbO2] kept lower in thrombosis patients and [Hb] kept lower in healthy people (p<0.001) (2) [HbO2] kept increasing in the thrombosis leg but decreasing in healthy leg for the patients after thrombolytic therapy, and coincidently, [HbO2] acted consistent just when the patients were cured and left. Our study successfully extended the application of NIRS in noninvasive, continuous, and low-cost monitoring of thrombosis in clinics. Our findings showed the powerful potential of [HbO2] by NIRS in diagnosis and therapeutic effect evaluation of thrombosis.

  20. Plant invasions and extinction debts.

    PubMed

    Gilbert, Benjamin; Levine, Jonathan M

    2013-01-29

    Whether introduced species invasions pose a major threat to biodiversity is hotly debated. Much of this debate is fueled by recent findings that competition from introduced organisms has driven remarkably few plant species to extinction. Instead, native plant species in invaded ecosystems are often found in refugia: patchy, marginal habitats unsuitable to their nonnative competitors. However, whether the colonization and extinction dynamics of these refugia allow long-term native persistence is uncertain. Of particular concern is the possibility that invasive plants may induce an extinction debt in the native flora, where persistence over the short term masks deterministic extinction trajectories. We examined how invader impacts on landscape structure influence native plant persistence by combining recently developed quantitative techniques for evaluating metapopulation persistence with field measurements of an invaded plant community. We found that European grass invasion of an edaphically heterogeneous California landscape has greatly decreased the likelihood of the persistence of native metapopulations. It does so via two main pathways: (i) decreasing the size of native refugia, which reduces seed production and increases local extinction, and (ii) eroding the dispersal permeability of the matrix between refugia, which reduces their connectivity. Even when native plant extinction is the deterministic outcome of invasion, the time to extinction can be on the order of hundreds of years. We conclude that the relatively short time since invasion in many parts of the world is insufficient to observe the full impact of plant invasions on native biodiversity.

  1. Using flow information to support 3D vessel reconstruction from rotational angiography

    SciTech Connect

    Waechter, Irina; Bredno, Joerg; Weese, Juergen; Barratt, Dean C.; Hawkes, David J.

    2008-07-15

    For the assessment of cerebrovascular diseases, it is beneficial to obtain three-dimensional (3D) morphologic and hemodynamic information about the vessel system. Rotational angiography is routinely used to image the 3D vascular geometry and we have shown previously that rotational subtraction angiography has the potential to also give quantitative information about blood flow. Flow information can be determined when the angiographic sequence shows inflow and possibly outflow of contrast agent. However, a standard volume reconstruction assumes that the vessel tree is uniformly filled with contrast agent during the whole acquisition. If this is not the case, the reconstruction exhibits artifacts. Here, we show how flow information can be used to support the reconstruction of the 3D vessel centerline and radii in this case. Our method uses the fast marching algorithm to determine the order in which voxels are analyzed. For every voxel, the rotational time intensity curve (R-TIC) is determined from the image intensities at the projection points of the current voxel. Next, the bolus arrival time of the contrast agent at the voxel is estimated from the R-TIC. Then, a measure of the intensity and duration of the enhancement is determined, from which a speed value is calculated that steers the propagation of the fast marching algorithm. The results of the fast marching algorithm are used to determine the 3D centerline by backtracking. The 3D radius is reconstructed from 2D radius estimates on the projection images. The proposed method was tested on computer simulated rotational angiography sequences with systematically varied x-ray acquisition, blood flow, and contrast agent injection parameters and on datasets from an experimental setup using an anthropomorphic cerebrovascular phantom. For the computer simulation, the mean absolute error of the 3D centerline and 3D radius estimation was 0.42 and 0.25 mm, respectively. For the experimental datasets, the mean absolute

  2. Effectiveness of theophylline prophylaxis of renal impairment after coronary angiography in patients with chronic renal insufficiency.

    PubMed

    Huber, Wolfgang; Schipek, Chrysantha; Ilgmann, Kathrin; Page, Michael; Hennig, Michael; Wacker, Annette; Schweigart, Ursula; Lutilsky, Leopoldo; Valina, Christian; Seyfarth, Melchior; Schömig, Albert; Classen, Meinhard

    2003-05-15

    Contrast media can lead to renal impairment that results in longer hospitalization and increased mortality. Adenosine is a crucial mediator of contrast-induced nephropathy (CIN; an increase in serum creatinine of >or=0.5 mg/dl within 48 hours). Therefore, it was the purpose of our study to investigate whether the adenosine antagonist theophylline reduces the incidence of CIN after coronary angiography. We also characterized risk factors for CIN after coronary angiography. One hundred patients with serum creatinine concentrations of >or=1.3 mg/dl randomly received 200 mg IV theophylline or placebo 30 minutes before coronary angiography (amount of contrast medium >or=100 ml). Patients who received theophylline and the controls were comparable with regard to baseline creatinine levels (means +/- SD) (1.65 +/- 0.41 vs 1.72 +/- 0.69 mg/dl) and the amount of contrast medium received (235 +/- 89 vs 261 +/- 139 ml). Theophylline significantly reduced the incidence of CIN (4% vs 20%, p = 0.0138). With placebo, creatinine significantly increased at 12 (1.82 +/- 0.79 mg/dl, p = 0.0057), 24 (1.90 +/- 0.86 mg/dl, p = 0.0001), and 48 hours (1.90 +/- 0.89 mg/dl, p = 0.0007) after administration of contrast medium. With pretreatment with theophylline, mean creatinine only increased 24 hours after contrast medium administration (1.70 +/- 0.40 mg/dl, p = 0.029), but was stable 12 hours (1.65 +/- 0.43 mg/dl, p = 0.99) and 48 hours after contrast medium administration (1.65 +/- 0.41 mg/dl, p = 0.99). The following parameters were significantly associated with contrast-induced renal impairment: Cigarroa quotient >5 (contrast medium [milliters] x serum creatinine/body weight [kg]), elevated troponin T, >300 ml of contrast medium, and emergency angiography. In conclusion, theophylline reduces the incidence of CIN in patients with chronic renal insufficiency undergoing coronary angiography. It should be used especially in patients receiving large amounts of contrast medium, and in

  3. Using flow information to support 3D vessel reconstruction from rotational angiography.

    PubMed

    Waechter, Irina; Bredno, Joerg; Weese, Juergen; Barratt, Dean C; Hawkes, David J

    2008-07-01

    For the assessment of cerebrovascular diseases, it is beneficial to obtain three-dimensional (3D) morphologic and hemodynamic information about the vessel system. Rotational angiography is routinely used to image the 3D vascular geometry and we have shown previously that rotational subtraction angiography has the potential to also give quantitative information about blood flow. Flow information can be determined when the angiographic sequence shows inflow and possibly outflow of contrast agent. However, a standard volume reconstruction assumes that the vessel tree is uniformly filled with contrast agent during the whole acquisition. If this is not the case, the reconstruction exhibits artifacts. Here, we show how flow information can be used to support the reconstruction of the 3D vessel centerline and radii in this case. Our method uses the fast marching algorithm to determine the order in which voxels are analyzed. For every voxel, the rotational time intensity curve (R-TIC) is determined from the image intensities at the projection points of the current voxel. Next, the bolus arrival time of the contrast agent at the voxel is estimated from the R-TIC. Then, a measure of the intensity and duration of the enhancement is determined, from which a speed value is calculated that steers the propagation of the fast marching algorithm. The results of the fast marching algorithm are used to determine the 3D centerline by backtracking. The 3D radius is reconstructed from 2D radius estimates on the projection images. The proposed method was tested on computer simulated rotational angiography sequences with systematically varied x-ray acquisition, blood flow, and contrast agent injection parameters and on datasets from an experimental setup using an anthropomorphic cerebrovascular phantom. For the computer simulation, the mean absolute error of the 3D centerline and 3D radius estimation was 0.42 and 0.25 mm, respectively. For the experimental datasets, the mean absolute

  4. Retinal functional imager (RFI): non-invasive functional imaging of the retina.

    PubMed

    Ganekal, S

    2013-01-01

    Retinal functional imager (RFI) is a unique non-invasive functional imaging system with novel capabilities for visualizing the retina. The objective of this review was to show the utility of non-invasive functional imaging in various disorders. Electronic literature search was carried out using the websites www.pubmed.gov and www.google.com. The search words were retinal functional imager and non-invasive retinal imaging used in combination. The articles published or translated into English were studied. The RFI directly measures hemodynamic parameters such as retinal blood-flow velocity, oximetric state, metabolic responses to photic activation and generates capillary perfusion maps (CPM) that provides retinal vasculature detail similar to flourescein angiography. All of these parameters stand in a direct relationship to the function and therefore the health of the retina, and are known to be degraded in the course of retinal diseases. Detecting changes in retinal function aid early diagnosis and treatment as functional changes often precede structural changes in many retinal disorders.

  5. Common Ground for Managing Invasive Annual Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive annual grasses often reach their full biological potential in ecosystems of the western United States. This suggests that crucial ecosystem "checks and balances" are not functioning. In other words, invasion occurs because ecosystems have lost resistance to invasion, and invasive plants a...

  6. Simplified Models of Non-Invasive Fractional Flow Reserve Based on CT Images

    PubMed Central

    Zhang, Jun-Mei; Zhong, Liang; Luo, Tong; Lomarda, Aileen Mae; Huo, Yunlong; Yap, Jonathan; Lim, Soo Teik; Tan, Ru San; Wong, Aaron Sung Lung; Tan, Jack Wei Chieh; Yeo, Khung Keong; Fam, Jiang Ming; Keng, Felix Yung Jih; Wan, Min; Su, Boyang; Zhao, Xiaodan; Allen, John Carson; Kassab, Ghassan S.; Chua, Terrance Siang Jin; Tan, Swee Yaw

    2016-01-01

    Invasive fractional flow reserve (FFR) is the gold standard to assess the functional coronary stenosis. The non-invasive assessment of diameter stenosis (DS) using coronary computed tomography angiography (CTA) has high false positive rate in contrast to FFR. Combining CTA with computational fluid dynamics (CFD), recent studies have shown promising predictions of FFRCT for superior assessment of lesion severity over CTA alone. The CFD models tend to be computationally expensive, however, and require several hours for completing analysis. Here, we introduce simplified models to predict noninvasive FFR at substantially less computational time. In this retrospective pilot study, 21 patients received coronary CTA. Subsequently a total of 32 vessels underwent invasive FFR measurement. For each vessel, FFR based on steady-state and analytical models (FFRSS and FFRAM, respectively) were calculated non-invasively based on CTA and compared with FFR. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value were 90.6% (87.5%), 80.0% (80.0%), 95.5% (90.9%), 88.9% (80.0%) and 91.3% (90.9%) respectively for FFRSS (and FFRAM) on a per-vessel basis, and were 75.0%, 50.0%, 86.4%, 62.5% and 79.2% respectively for DS. The area under the receiver operating characteristic curve (AUC) was 0.963, 0.954 and 0.741 for FFRSS, FFRAM and DS respectively, on a per-patient level. The results suggest that the CTA-derived FFRSS performed well in contrast to invasive FFR and they had better diagnostic performance than DS from CTA in the identification of functionally significant lesions. In contrast to FFRCT, FFRSS requires much less computational time. PMID:27187726

  7. Invasive and non-invasive assessment of portal hypertension.

    PubMed

    Leung, Jonathan Chung-Fai; Loong, Thomson Chi-Wang; Pang, James; Wei, Jeremy Lok; Wong, Vincent Wai-Sun

    2017-03-30

    Portal hypertension is the central driver of complications in patients with chronic liver diseases and cirrhosis. The diagnosis of portal hypertension has important prognostic and clinical implications. In particular, screening for varices in patients with portal hypertension can effectively reduce the morbidity and mortality of variceal bleeding. In this article, we review the invasive and non-invasive methods to assess portal hypertension. Hepatic venous pressure gradient remains the gold standard to measure portal pressure but is invasive and seldom performed outside expert centers and research settings. In recent years, a number of non-invasive tests of fibrosis have shown good correlation with liver histology. They also show promise in identifying patients with portal hypertension and large varices. As a result, the latest Baveno VI consensus guidelines endorse the use of liver stiffness measurement by transient elastography and platelet count as initial assessment to select patients for varices screening. On the other hand, the performance of non-invasive tests in assessing the response to non-selective beta-blockers or transjugular intrahepatic portosystemic shunting is either suboptimal or unclear.

  8. SOST Inhibits Prostate Cancer Invasion

    SciTech Connect

    Hudson, Bryan D.; Hum, Nicholas R.; Thomas, Cynthia B.; Kohlgruber, Ayano; Sebastian, Aimy; Collette, Nicole M.; Coleman, Matthew A.; Christiansen, Blaine A.; Loots, Gabriela G.

    2015-11-06

    Inhibitors of Wnt signaling have been shown to be involved in prostate cancer (PC) metastasis; however the role of Sclerostin (Sost) has not yet been explored. Here we show that elevated Wnt signaling derived from Sost deficient osteoblasts promotes PC invasion, while rhSOST has an inhibitory effect. In contrast, rhDKK1 promotes PC elongation and filopodia formation, morphological changes characteristic of an invasive phenotype. Furthermore, rhDKK1 was found to activate canonical Wnt signaling in PC3 cells, suggesting that SOST and DKK1 have opposing roles on Wnt signaling in this context. Gene expression analysis of PC3 cells co-cultured with OBs exhibiting varying amounts of Wnt signaling identified CRIM1 as one of the transcripts upregulated under highly invasive conditions. We found CRIM1 overexpression to also promote cell-invasion. These findings suggest that bone-derived Wnt signaling may enhance PC tropism by promoting CRIM1 expression and facilitating cancer cell invasion and adhesion to bone. We concluded that SOST and DKK1 have opposing effects on PC3 cell invasion and that bone-derived Wnt signaling positively contributes to the invasive phenotypes of PC3 cells by activating CRIM1 expression and facilitating PC-OB physical interaction. As such, we investigated the effects of high concentrations of SOST in vivo. In conclusion, we found that PC3-cells overexpressing SOST injected via the tail vein in NSG mice did not readily metastasize, and those injected intrafemorally had significantly reduced osteolysis, suggesting that targeting the molecular bone environment may influence bone metastatic prognosis in clinical settings.

  9. SOST Inhibits Prostate Cancer Invasion

    DOE PAGES

    Hudson, Bryan D.; Hum, Nicholas R.; Thomas, Cynthia B.; ...

    2015-11-06

    Inhibitors of Wnt signaling have been shown to be involved in prostate cancer (PC) metastasis; however the role of Sclerostin (Sost) has not yet been explored. Here we show that elevated Wnt signaling derived from Sost deficient osteoblasts promotes PC invasion, while rhSOST has an inhibitory effect. In contrast, rhDKK1 promotes PC elongation and filopodia formation, morphological changes characteristic of an invasive phenotype. Furthermore, rhDKK1 was found to activate canonical Wnt signaling in PC3 cells, suggesting that SOST and DKK1 have opposing roles on Wnt signaling in this context. Gene expression analysis of PC3 cells co-cultured with OBs exhibiting varyingmore » amounts of Wnt signaling identified CRIM1 as one of the transcripts upregulated under highly invasive conditions. We found CRIM1 overexpression to also promote cell-invasion. These findings suggest that bone-derived Wnt signaling may enhance PC tropism by promoting CRIM1 expression and facilitating cancer cell invasion and adhesion to bone. We concluded that SOST and DKK1 have opposing effects on PC3 cell invasion and that bone-derived Wnt signaling positively contributes to the invasive phenotypes of PC3 cells by activating CRIM1 expression and facilitating PC-OB physical interaction. As such, we investigated the effects of high concentrations of SOST in vivo. In conclusion, we found that PC3-cells overexpressing SOST injected via the tail vein in NSG mice did not readily metastasize, and those injected intrafemorally had significantly reduced osteolysis, suggesting that targeting the molecular bone environment may influence bone metastatic prognosis in clinical settings.« less

  10. Value of Single-Dose Contrast-Enhanced Magnetic Resonance Angiography Versus Intraarterial Digital Subtraction Angiography in Therapy Indications in Abdominal and Iliac Arteries

    SciTech Connect

    Schaefer, Philipp J. Schaefer, Fritz K. W.; Mueller-Huelsbeck, Stefan; Both, Markus; Heller, Martin; Jahnke, Thomas

    2007-06-15

    The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committee was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weight in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30{sup o}, field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses {>=}50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies.

  11. Imaging for approach selection of TAVI: assessment of the aorto-iliac tract diameter by computed tomography-angiography versus projection angiography.

    PubMed

    Wiegerinck, E M A; Marquering, H A; Oldenburger, N Y; Elattar, M A; Planken, R N; De Mol, B A J M; Piek, J J; Baan, J

    2014-02-01

    The choice of preferred access route for transcatheter aortic valve implantation (TAVI) is mainly guided by the minimal aorto-femoral tract diameter. Currently, projection angiography (XA) and CT-angiography (CTA) are used interchangeably to assess this diameter in the TAVI work-up. We aimed to assess the agreement of XA and CTA diameter measurements in TAVI candidates. Diameters of 700 aorta-iliac segments of 102 TAVI candidates were analyzed on both XA and CTA. The diameters on XA were measured manually, for the CTA-based analysis semi-automated segmentation software was used. Paired sample T test was used to evaluate differences in diameter measurements between the modalities. Disagreement on the suitability for a transfemoral (TF)-TAVI approach was identified. The interobserver agreement for both measurements was assessed by calculating the intraclass correlation coefficient (ICC). The average diameters were 10.1 ± 1.8 mm and 8.4 ± 1.7 for XA and CTA respectively. The mean paired difference was 1.73 mm (p < 0.001). For 18 patients (17.6 %) diameters measured on CTA images, were bilaterally less than 6 mm, whilst XA indicated a minimum diameter exceeding 6 mm. For both modalities, the interobserver agreement was excellent (ICC 0.95). Diameters measured semi-automatically on CTA were statistically significantly smaller compared to XA. This should be acknowledged in the work-up for selecting the most appropriate approach for TAVI. In our population 17.6 % of patients would have been denied a transfemoral TAVI based on CTA measurements, whilst XA suggested diameters sufficient for a TF approach.

  12. Value of single-dose contrast-enhanced magnetic resonance angiography versus intraarterial digital subtraction angiography in therapy indications in abdominal and iliac arteries.

    PubMed

    Schaefer, Philipp J; Schaefer, Fritz K W; Mueller-Huelsbeck, Stefan; Both, Markus; Heller, Martin; Jahnke, Thomas

    2007-01-01

    The objective of the study was to prove the value of single-dose contrast-enhanced magnetic resonance angiography [three-dimensional (3D) ceMRA] in abdominal and iliac arteries versus the reference standard intra-arterial digital subtraction angiography (i.a.DSA) when indicating a therapy. Patients suspected of having abdominal or iliac artery stenosis were included in this study. A positive vote of the local Ethics Committe was given. After written informed consent was obtained, 37 patients were enrolled, of which 34 were available for image evaluation. Both 3D ceMRA and i.a. DSA were performed for each patient. The dosage for 3D ceMRA was 0.1 mmol/kg body weight in a 1.5-T scanner with a phased-array coil. The parameters of the 3D-FLASH sequence were as follows: TR/TE 4.6/1.8 ms, effective thickness 3.5 mm, matrix 512 x 200, flip angle 30 degrees , field of view 420 mm, TA 23 s, coronal scan orientation. Totally, 476 vessel segments were evaluated for stenosis degree by two radiologists in a consensus fashion in a blinded read. For each patient, a therapy was proposed, if clinically indicated. Sensitivity, specificity, positive and negative predictive values, and accuracy for stenoses > or = 50% were 68%, 92%, 44%, 97%, and 90%, respectively. In 13/34 patients, a discrepancy was found concerning therapy decisions based on MRA findings versus therapy decisions based on the reference standard DSA. The results showed that the used MRA imaging technique of abdominal and iliac arteries is not competitive to i.a. DSA, with a high rate of misinterpretation of the MRAs resulting in incorrect therapies.

  13. Non-invasive evaluation of culprit lesions by PET imaging: shifting the clinical paradigm away from resultant anatomy toward causative physiology.

    PubMed

    Caobelli, Federico; Bengel, Frank M

    2014-12-01

    Although coronary angiography is the gold standard for assessing coronary artery disease (CAD), there is at best a weak correlation between degree of stenosis and the risk of developing cardiac events. Plaque rupture is the most common type of plaque complication, accounting for about 70% of fatal acute myocardial infarctions or sudden coronary deaths. Recently, the feasibility of (18)F-fluoride PET/CT in the evaluation of atherosclerotic lesions was assessed. Radionuclide techniques allow non-invasive biologic assessment of atherosclerotic plaques. This may help to further shift the clinical paradigm in coronary disease away from anatomy toward causative physiology and biology.

  14. Non-invasive evaluation of culprit lesions by PET imaging: shifting the clinical paradigm away from resultant anatomy toward causative physiology

    PubMed Central

    Bengel, Frank M.

    2014-01-01

    Although coronary angiography is the gold standard for assessing coronary artery disease (CAD), there is at best a weak correlation between degree of stenosis and the risk of developing cardiac events. Plaque rupture is the most common type of plaque complication, accounting for about 70% of fatal acute myocardial infarctions or sudden coronary deaths. Recently, the feasibility of 18F-fluoride PET/CT in the evaluation of atherosclerotic lesions was assessed. Radionuclide techniques allow non-invasive biologic assessment of atherosclerotic plaques. This may help to further shift the clinical paradigm in coronary disease away from anatomy toward causative physiology and biology. PMID:25610799

  15. Coronary CT angiography using 64 detector rows: methods and design of the multi-centre trial CORE-64

    PubMed Central

    Vavere, Andrea L.; Rochitte, Carlos E.; Niinuma, Hiroyuki; Arbab-Zadeh, Armin; Paul, Narinder; Hoe, John; de Roos, Albert; Yoshioka, Kunihiro; Lemos, Pedro A.; Bush, David E.; Lardo, Albert C.; Texter, John; Brinker, Jeffery; Cox, Christopher; Clouse, Melvin E.; Lima, João A. C.

    2012-01-01

    Multislice computed tomography (MSCT) for the noninvasive detection of coronary artery stenoses is a promising candidate for widespread clinical application because of its noninvasive nature and high sensitivity and negative predictive value as found in several previous studies using 16 to 64 simultaneous detector rows. A multi-centre study of CT coronary angiography using 16 simultaneous detector rows has shown that 16-slice CT is limited by a high number of nondiagnostic cases and a high false-positive rate. A recent meta-analysis indicated a significant interaction between the size of the study sample and the diagnostic odds ratios suggestive of small study bias, highlighting the importance of evaluating MSCT using 64 simultaneous detector rows in a multi-centre approach with a larger sample size. In this manuscript we detail the objectives and methods of the prospective “CORE-64” trial (“Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography using 64 Detectors”). This multi-centre trialwas unique in that it assessed the diagnostic performance of 64-slice CT coronary angiography in nine centres worldwide in comparison to conventional coronary angiography. In conclusion, the multi-centre, multi-institutional and multi-continental trial CORE-64 has great potential to ultimately assess the per-patient diagnostic performance of coronary CT angiography using 64 simultaneous detector rows. PMID:18998142

  16. Preoperative evaluation value of aortic arch lesions by multidetector computed tomography angiography in type A aortic dissection

    PubMed Central

    Huang, Fang; Chen, Qiang; Lai, Qing-quan; Huang, Wen-han; Wu, Hong; Li, Wei-cheng

    2016-01-01

    Abstract The purpose of this study was to preoperatively evaluate the value of aortic arch lesions by multidetector computed tomography (MDCT) angiography in type A aortic dissection (AD). From January 2013 to December 2015, we enrolled 42 patients with type A AD who underwent MDCT angiography in our hospital. The institutional database of patients was retrospectively reviewed to identify MDCT angiography examinations for type A AD. Surgical corrections were conducted in all patients to confirm diagnostic accuracy. In this study, the diagnostic accuracy of MDCT angiography was 100% in all 42 patients. The intimal tear site locations that were identified in patients included the ascending aorta (n = 25), aortic arch (n = 12), and all other sites (n = 5). Compared with the control group, there were significant differences in the aortic arch anatomy among the cases. Regarding the distance between the left common carotid and left subclavian arteries, compared with the control group, most cases with type A AD had a significant variation. MDCT angiography plays an important role in detecting aortic arch lesions of type A AD, especially in determining the location of the intimal entry site and change of branch blood vessels. Surgeons can formulate an appropriate operating plan, according to the preoperative MDCT diagnosis information. PMID:27684852

  17. Duplex ultrasound and computed tomography angiography in the follow-up of endovascular abdominal aortic aneurysm repair: a comparative study*

    PubMed Central

    Cantador, Alex Aparecido; Siqueira, Daniel Emílio Dalledone; Jacobsen, Octavio Barcellos; Baracat, Jamal; Pereira, Ines Minniti Rodrigues; Menezes, Fábio Hüsemann; Guillaumon, Ana Terezinha

    2016-01-01

    Objective To compare duplex ultrasound and computed tomography (CT) angiography in terms of their performance in detecting endoleaks, as well as in determining the diameter of the aneurysm sac, in the postoperative follow-up of endovascular abdominal aortic aneurysm repair. Materials and Methods This was a prospective study involving 30 patients who had undergone endovascular repair of infrarenal aortoiliac aneurysms. Duplex ultrasound and CT angiography were performed simultaneously by independent radiologists. Measurements of the aneurysm sac diameter were assessed, and the presence or absence of endoleaks was determined. Results The average diameter of the aneurysm sac, as determined by duplex ultrasound and CT angiography was 6.09 ± 1.95 and 6.27 ± 2.16 cm, respectively. Pearson's correlation coefficient showing a statistically significant correlation (R = 0.88; p < 0.01). Comparing the duplex ultrasound and CT angiography results regarding the detection of endoleaks, we found that the former had a negative predictive value of 92.59% and a specificity of 96.15%. Conclusion Our results show that there is little variation between the two methods evaluated, and that the choice between the two would have no significant effect on clinical management. Duplex ultrasound could replace CT angiography in the postoperative follow-up of endovascular aneurysm repair of the infrarenal aorta, because it is a low-cost procedure without the potential clinical complications related to the use of iodinated contrast and exposure to radiation. PMID:27777476

  18. Cell migration and invasion assays.

    PubMed

    Moutasim, Karwan A; Nystrom, Maria L; Thomas, Gareth J

    2011-01-01

    A number of in vitro assays have been developed to study tumor cell motility. Historically, assays have been mainly monocellular, where carcinoma cells are studied in isolation. Scratch assays can be used to study the collective and directional movement of populations of cells, whereas two chamber assays lend themselves to the analysis of chemotactic/haptotactic migration and cell invasion. However, an inherent disadvantage of these assays is that they grossly oversimplify the complex process of invasion, lacking the tumor structural architecture and stromal components. Organotypic assays, where tumor cells are grown at an air/liquid interface on gels populated with stromal cells, are a more physiologically relevant method for studying 3-dimensional tumor invasion.

  19. Conceptual design of an 8 Tesla superconducting wiggler for a dedicated digital subtraction angiography source

    SciTech Connect

    Blum, E.B.

    1993-09-01

    One of the most important techniques used to diagnose heart disease is coronary angiography. Coronary angiography is only used when it is absolutely essential because of the risk of fatalities and other serious complications arising from the insertion of the catheter. The technique also exposes the patients to large amounts of x-rays. Research, begun at SSRL and continued on the X17 beam line at NSLS, demonstrated the feasibility of imaging human coronary arteries following venous injection of the contrast agent. The technique, caged digital subtraction angiography (DSA), uses two monochromatic beams of x-rays, one slightly above and one slightly below the iodine K absorption edge (33.169 KeV) to collect simultaneous images. When the two images are subtracted, the contrast agent, contained primarily in the blood vessels, is revealed and the background that is common to both images is suppressed. The images must be collected during a single heartbeat to avoid blurring from motion of the blood vessels. Conventional x-ray sources are too weak to provide the intense flux that is required in the narrow energy bandwidth of the beams. Only the most powerful synchrotron radiation beams from wiggler magnet sources can provide the intensity required in the short exposure time. Although DSA experiments have shown promise, they have been conducted at large, research synchrotron radiation facilities. A small, dedicated source will be needed before DSA can be used as a standard medical procedure. Such x-ray sources as laser backscattering, Cherenkov radiation, parametric x-radiation, and channeling radiation have been suggested for hospital based DSA sources but none of them appear to produce enough flux to be useful. Barring the discovery of a new source of intense x-rays, only synchrotron radiation seems to meet the requirements for DSA. This report briefly describes the preliminary design of a high field, superconducting wiggler magnet that can be used as a DSA source.

  20. Gadomer-17-enhanced 3D navigator-echo MR angiography of the pulmonary arteries in pigs.

    PubMed

    Abolmaali, Nasreddin D; Hietschold, Volker; Appold, Steffen; Ebert, Wolfgang; Vogl, Thomas J

    2002-03-01

    The goal of this study was visualisation and quality assessment of the pulmonary arteries in pigs with modified navigator-echo magnetic resonance angiography using an intravascular contrast agent. Five sedated pigs were examined in a clinical 1.5-T system with modified three-dimensional navigator-echo magnetic resonance angiography (slice thickness 3 mm, pixel size 2.4x1.8 mm2) to evaluate the pulmonary arteries. Using a phased-array four-element thorax coil the entire thorax was scanned before and after intravenous infusion of a gadolinium-based intravascular contrast agent. Assessment of image quality, enhancement-related contrast-to-noise ratio (CNR) measurements and improvement of visibility of peripheral pulmonary vessels was performed. Improvement of quality using Gadomer-17 was found for smaller vessels; pulmonary trunks and the main pulmonary arteries were sufficiently imaged without enhancement. Mean rise of CNR measured in the pulmonary trunks was 28.64% ( P=0.0002), mean rise of CNR in the main pulmonary arteries and the segmental arteries were 79.6% and 148.2%, respectively. Mean distance between the visible peripheral end of 60 sub-segmental arteries and the inner thoracic wall was 12.2 +/- 0.4 mm, and was significantly ( P=0.00002) reduced after contrast infusion to 8.0 +/- 0.4 mm. The combination of inherent flow sensitivity of navigator-echo angiography and Gadomer-17 proved effective for imaging of the pulmonary arteries. In contrast to standard contrast-enhanced pulmonary MRA studies, breath holding is not required. Further studies and the evaluation of findings of patients suffering from pulmonary embolism are needed to evaluate the possible benefits of a higher spatial resolution which is achievable using navigator-echo techniques in contrast to the higher temporal resolution of ultra-fast pulmonary MRA.

  1. Reconstruction of 3D angiography data using the algebraic reconstruction technique (ART)

    NASA Astrophysics Data System (ADS)

    Hampton, Carnell J.; Hemler, Paul F.

    2001-07-01

    Three-dimensional angiographic reconstrcution has emerged as an alternative to the traditional depiction of aneurysm angioarchitecture provided by 2-D perspective projections acquired by digital subtraction angiography (DSA) and fluoroscopy. One clinical application of research involving 3-D angiographic reconstruction is intraoperative localization and visualization during aneurysm embolization procedures. For this procedure, reconstruction quality is important for the 3-D reconstruction of anatomy as well as for the reconstrucution of intraaneurysm coils imaged endovascularly and subsequently rendered within an existing 3-D anatomic representation. Rotational angiography involves the acquisition of a series of 2-D, cone-beam projections of intracranial anatomy by a rotating x-ray gantry following a single injection of contrast media. Our investigation focuses on the practicality of using methods that employ algebraic reconstruction techniques (ART) to reconstruct 3-D data from 2-D cone-beam projections acquired using rotational angiography during embolization procedures. Important to our investigation are issues that arise within the implementation of the projection, correction and backprojection steps of the reconstruction algorithm that affect reconstruction quality. Several methods are discussed to perform accurate voxel grid projection and backprojection. Various parameters of the reconstruction algorithm implementation are also investigated. Preliminary results indicating that quality 3-D reconstructions from 2-D projections of synthetic volumes are presented. Further modifications to our implementation hold the promise of achieving accurate reconstruction results with a lower computation cost than the algorithm implemention used for this study. We have concluded that methods to extend the traditional ART algorithm for cone-beam projection acquisition produce quality 3-D reconstructions.

  2. Periventricular anastomosis in moyamoya disease: detecting fragile collateral vessels with MR angiography.

    PubMed

    Funaki, Takeshi; Takahashi, Jun C; Yoshida, Kazumichi; Takagi, Yasushi; Fushimi, Yasutaka; Kikuchi, Takayuki; Mineharu, Yohei; Okada, Tomohisa; Morimoto, Takaaki; Miyamoto, Susumu

    2016-06-01

    OBJECT The authors' aim in this paper was to determine whether periventricular anastomosis, a novel term for the abnormal collateral vessels typical of moyamoya disease, is reliably measured with MR angiography and is associated with intracranial hemorrhage. METHODS This cross-sectional study sampled consecutive patients with moyamoya disease or moyamoya syndrome at a single institution. Periventricular anastomoses were detected using MR angiography images reformatted as sliding-thin-slab maximum-intensity-projection coronal images and were scored according to 3 subtypes: lenticulostriate, thalamic, and choroidal types. The association between periventricular anastomosis and hemorrhagic presentation at onset was evaluated using multivariate analyses. RESULTS Of 136 eligible patients, 122 were analyzed. Eighteen (14.8%) patients presented with intracranial hemorrhage with neurological symptoms at onset. Intra- and interrater agreement for rating of the periventricular anastomosis score was good (κw = 0.65 and 0.70, respectively). The prevalence of hemorrhagic presentation increased with the periventricular anastomosis score: 2.8% for Score 0, 8.8% for Score 1, 18.9% for Score 2, and 46.7% for Score 3 (p < 0.01 for trend). Univariate analysis revealed that age (p = 0.02) and periventricular anastomosis score (p < 0.01) were factors tentatively associated with hemorrhagic presentation. The score remained statistically significant after adjustment for age (OR 3.38 [95% CI 1.84-7.00]). CONCLUSIONS The results suggest that periventricular anastomosis detected with MR angiography can be scored with good intra- and interrater reliability and is associated with hemorrhagic presentation at onset in moyamoya disease. The clinical utility of periventricular anastomosis as a predictor for hemorrhage should be validated in further prospective studies.

  3. Cerebral arteriovenous malformations: improved nidus demarcation by means of dynamic tagging MR-angiography.

    PubMed

    Essig, M; Engenhart, R; Knopp, M V; Bock, M; Scharf, J; Debus, J; Wenz, F; Hawighorst, H; Schad, L R; van Kaick, G

    1996-01-01

    Our purpose was to further improve the target volume definition for radiosurgical treatment of cerebral arteriovenous malformations (AVMs) by means of dynamic MRA (dMRA) using a blood bolus tagging sequence. We therefore compare this technique with 3D-TOF-MRA and transfemoral high resolution angiography in plain film technique. Twenty patients with angiographically proven cerebral AVMs were investigated by dMRA, TOF-MRA, and conventional angiography during the MR-assisted radiosurgical planning protocol. The patient's head was fixed in an MR-compatible stereotactic device. The different angiography techniques were evaluated by consensus of two radiologists. AVMs were characterized by the number and origin of feeding arteries, the maximum diameter of the AVM nidus, and the venous drainage pattern. Dynamic MRA was able to demonstrate the complete AVM characteristics and hemodynamics in 12 out of 20 patients. In three patients with an AVM nidus smaller than 1 cm in diameter the technique could not reliably depict the malformation. Technical problems due to steel screws and pins in the initially used stereotactic frame occurred in five patients. Due to reduced vessel overlap and the lack of disturbances caused by formations with short T1 time, dMRA was superior to TOF-MRA in the detection and the exact localization of the AVM nidus in four patients. We conclude that dMRA is able to demonstrate reliably AVM characteristics and hemodynamics in AVMs with a nidus larger than 1 cm in diameter. Because of the improved demarcation of the AVM nidus, this technique may be a valuable adjunct to radiosurgery planning of cerebral AVMs.

  4. Compensation for Reflectance Variation in Vessel Density Quantification by Optical Coherence Tomography Angiography

    PubMed Central

    Gao, Simon S.; Jia, Yali; Liu, Liang; Zhang, Miao; Takusagawa, Hana L.; Morrison, John C.; Huang, David

    2016-01-01

    Purpose To compensate for reflectance variation when quantifying vessel density by optical coherence tomography angiography (OCTA). Methods Healthy participants received 6×6-mm macular and 4.5×4.5-mm optic nerve head (ONH) angiography scans on a 70-kHz spectral-domain optical coherence tomography system. The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to compute the OCTA signal. Mean reflectance projection and maximum decorrelation projection were used to create en face OCT and OCTA images. Background OCTA noise in static tissue was evaluated in the foveal avascular zone (FAZ). Vessel density was calculated from en face retinal OCTA that was binarized according to a decorrelation threshold. Results The average retinal decorrelation noise in the FAZ was linearly related to the average logarithmic-scale OCT reflectance signal. Based on this relationship, a reflectance-adjusted decorrelation threshold equation was developed to filter out 97.5% of background OCTA noise. A fixed threshold was also used for comparison. The superficial vascular complex vessel density in the macula and ONH were significantly correlated with reflectance signal strength index (SSI) using the fixed threshold. This correlation was removed by using the reflectance-adjusted threshold. Reflectance compensation reduced population variation in 25 healthy eyes from 8.5% to 4.8% (coefficient of variation) in the macula and from 6.7% to 5.4% in the peripapillary region. Within-visit repeatability also improved from 4.4% to 1.8% in the macula and from 3% to 1.7% in the peripapillary region. Conclusions Compensating for reflectance variation resulted in more reliable vessel density quantification in OCTA. PMID:27571015

  5. Intraoperative indocyanine green angiography for the objective measurement of blood flow

    PubMed Central

    Park, Ho-Chul; Han, Sang-Ah; Ahn, Hyung Joon

    2016-01-01

    Purpose Intraoperative assessment of tissue perfusion is important to predict wound healing or improvement of symptoms in patients with peripheral arterial disease (PAD) or vascular trauma. There is no widely accepted standard for intraoperative measurement of tissue perfusion. Here, we report the use of indocyanine green (ICG)-based angiography to determine the blood flow in patients with PAD and vascular trauma. Methods The SPY fluorescent imaging system was utilized. A dose of 3–5 mL of ICG (2.5 mg/mL) was injected intravenously followed by a 10 mL normal saline flush. The SPY imaging system was used to quantitatively assess perfusion. During the study period, the SPY imaging system was applied in 4 patients with PAD and one patient with vascular trauma. Results In 3 patients with PAD associated with an ischemic wound, complete wound healing was achieved with the indication of viable tissue by the SPY system. In one patient with severe claudication in both lower extremities, the ICG angiography was used to determine the increased blood flow after revascularization. In the case of vascular trauma, this imaging system enabled the delineation of viability of the injured tissue. Conclusion ICG angiography can determine the surface tissue viability in PAD patients. In cases of severe vascular trauma,the SPY system can be used to determine tissue perfusion. Further study is warranted to define the definite utility of this technology to assess perfusion, response to revascularization, and potentially, to predict the likelihood of wound healing. PMID:27186573

  6. Sensitivity of EUS and ERCP Endoscopic Procedures in the Detection of Pancreatic Cancer During Preoperative Staging Correlated with CT and CT Angiography Imaging Methods

    PubMed Central

    Vukobrat-Bijedic, Zora; Husic-Selimovic, Azra; Bijedic, Nina; Gornjakovic, Srdjan; Sofic, Amela; Gogov, Bisera; Bjelogrlic, Ivana; Mehmedovic, Amila; Glavas, Sanjin

    2014-01-01

    The goal: The goal of this work was to give advantage to EUS as endoscopic method in diagnosis and following therapeutic treatment of pancreatic cancer in relation to radiological methods of CT and CTA. Material and Methods: The study included 49 patients, 20 women and 29 men hospitalized at the Clinic for gastroenterohepatology, due to suspicion on pancreatic cancer during observed 2 years period. All cancers were histologically and cytologically confirmed. The patients underwent ERCP as a mandatory part of staging and all patients underwent endoscopic ultrasound as well as CT or CT angiography. Results: Testing of differences was carried out using Fisher’s exact test in open-source software R. The following characteristics were tested: involvement of the blood vessels, lymph nodes, metastases, tumor size and duodenum infiltration. Results showed statistically significant difference at the 0.05 level for EUS, CT and CT angiography. Risk ratio showed that EUS is less effective in detecting infiltration of blood vessels within a malignant process then CTA where RR=0.52, CI 0.2–1.38, p-value=0.33. EUS and CTA are equal in the diagnosis of enlarged lymph nodes affected by malignancy where RR=1.3, CI 0.75–1.42, p-value=0.09. Comparison according to distant metastases showed that EUS is less effective compared to CT in approximately 30% of cases. In the diagnosis of duodenal infiltration EUS is in 5% of cases less accurate than the CT with the RR=0.95, CI 0.27–3.32, p-value=0.76, but the CTA method is more efficient because the comparison of EUS and CTA showed RR=12.52, CI 0.2–1.38, p-value=0.33. EUS as a diagnostic method is dominant in determining the size of malignant lesions located in the pancreas as compared to CT and CTA. Conclusion: EUS as endoscopic method compared to CT and CTA is one of the more invasive methods of examination but due to its ability to be performed immediately, to locate a changes smaller than 5 mm and the target biopsy option, to

  7. Weaknesses in regional primary coronary angioplasty programs: is there still a role for a pharmaco-invasive approach?

    PubMed

    Danchin, Nicolas; Dos Santos Teixeira, Nelson; Puymirat, Etienne

    2014-08-01

    All guidelines recommend primary percutaneous coronary intervention as the default strategy for achieving reperfusion in ST-segment elevation myocardial infarction patients. These recommendations are based upon randomized trials which compared primary percutaneous coronary intervention with stand-alone intravenous fibrinolysis. Since the time these trials were performed, however, it has been shown in further trials that use of rescue percutaneous coronary intervention in patients without signs of reperfusion after lysis, and routine coronary angiography within 24 h of the administration of lysis for all other patients, substantially improved the results of intravenous fibrinolytic treatment. This has led to proposing the pharmaco-invasive strategy as an alternative to primary percutaneous coronary intervention. Actually, it is not uncommon that circumstances prevent performing primary percutaneous coronary intervention within the recommended time limits set by the guidelines. In such cases, using a pharmaco-invasive strategy may constitute a valid alternative. Both the STREAM randomized trial and real-world experience, in particular the long-term results from the FAST-MI registry, suggest that the pharmaco-invasive strategy, when used in an appropriate population, compares favorably with primary percutaneous coronary intervention. Therefore, implementing a pharmaco-invasive strategy protocol may be an important complement to compensate for potential weaknesses in ST-segment elevation myocardial infarction networks.

  8. Approximating spatially exclusive invasion processes

    NASA Astrophysics Data System (ADS)

    Ross, Joshua V.; Binder, Benjamin J.

    2014-05-01

    A number of biological processes, such as invasive plant species and cell migration, are composed of two key mechanisms: motility and reproduction. Due to the spatially exclusive interacting behavior of these processes a cellular automata (CA) model is specified to simulate a one-dimensional invasion process. Three (independence, Poisson, and 2D-Markov chain) approximations are considered that attempt to capture the average behavior of the CA. We show that our 2D-Markov chain approximation accurately predicts the state of the CA for a wide range of motility and reproduction rates.

  9. Recent Advances in Invasive Cardiology

    PubMed Central

    Garbe, George J.

    1987-01-01

    This paper describes recent advances in invasive cardiology that enable the primary-care physician to offer his/her patient a wider range of effective treatments. Major developments in the investigation and management of the acute coronary syndromes, unstable angina and myocardial infarction, have revolutionized the care of patients with these conditions. The primary-care physician must be aware of the treatment modalities, the lines of referral, and strategies for management available in his/her clinical setting to allow prompt application of these modalities. A sampling of exciting advances in other areas of invasive cardiology are also described. PMID:21263906

  10. A Focal Chorioretinal Bartonella Lesion Analyzed by Optical Coherence Tomography Angiography.

    PubMed

    Pichi, Francesco; Srivastava, Sunil K; Levinson, Ashleigh; Baynes, Kimberly M; Traut, Caitlyn; Lowder, Careen Y

    2016-06-01

    Neovascularization may be associated with cat-scratch neuroretinitis in the absence of retinal vascular occlusion. Bartonella organisms establish an intimate relationship with the vascular endothelium, causing angioproliferative lesions, which might represent a dedicated pathogenic strategy for expanding the bacterial host cell habitat. In the eye, pathological angiogenesis caused by Bartonella has been described as peripapillary or macular choroidal neovascularization, but the presence of neovascularization within foci of chorioretinitis has never before been reported. The authors present a case of Bartonella chorioretinitis in which optical coherence tomography angiography, by detecting erythrocyte motion, was able to identify neovessels inside the infectious focus. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:585-588.].

  11. Swept-Source OCT Angiography Shows Sparing of the Choriocapillaris in Multiple Evanescent White Dot Syndrome.

    PubMed

    Yannuzzi, Nicolas A; Swaminathan, Swarup S; Zheng, Fang; Miller, Andrew; Gregori, Giovanni; Davis, Janet L; Rosenfeld, Philip J

    2017-01-01

    Two women with unilateral vision loss from multiple evanescent white dot syndrome were imaged serially with swept-source optical coherence tomography (SS-OCT). En face wide-field structural images revealed peripapillary outer photoreceptor disruption better than conventional fundus autofluorescence imaging. OCT angiography (OCTA) imaging showed preservation of flow within the retinal vasculature and choriocapillaris. As OCTA imaging of the choriocapillaris continues to evolve, these images may lay the groundwork for future investigation. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:69-74.].

  12. Invited review-Computed tomographic angiography (CTA) of the thoracic cardiovascular system in companion animals.

    PubMed

    Drees, Randi; François, Christopher J; Saunders, Jimmy H

    2014-01-01

    Computed tomographic angiography (CTA) of the thoracic cardiovascular system is offering new diagnostic opportunities in companion animal patients with the increasing availability of multidetector-row computed tomographic (MDCT) units in veterinary facilities. Optimal investigation of the systemic, pulmonary, and coronary circulation provides unique challenges due to the constant movement of the heart, the small size of several of the structures of interest, and the dependence of angiographic quality on various contrast bolus design and patient factors. Technical and practical aspects of thoracic cardiovascular CTA are reviewed in light of the currently available veterinary literature and future opportunities given utilizing MDCT in companion animal patients with suspected thoracic cardiovascular disease.

  13. Optical coherence tomography angiography and fundus autofluorescence in the eyes with choroideremia

    PubMed Central

    Kato, Maki; Maruko, Ichiro; Koizumi, Hideki; Iida, Tomohiro

    2017-01-01

    A 65-year-old man with presumed choroideremia with preserved central vision was examined by fundus autofluorescence (FAF) and optical coherence tomography angiography (OCTA). FAF showed an isolated area of hyperautofluorescence that involved the fovea. Although the choroid capillary slab of the OCTA showed the medium and large choroidal vessels inferior to the area of retinal pigment epithelium (RPE) atrophy, the choriocapillaris was visible in a relatively wider area than the hyperautofluorescent area in the FAF images. FAF and OCTA images allowed us to detect damage of the RPE before the choriocapillaris atrophy in a case of presumed choroideremia with preserved central vision. PMID:28062428

  14. Decision analysis in clinical cardiology: When is coronary angiography required in aortic stenosis

    SciTech Connect

    Georgeson, S.; Meyer, K.B.; Pauker, S.G. )

    1990-03-15

    Decision analysis offers a reproducible, explicit approach to complex clinical decisions. It consists of developing a model, typically a decision tree, that separates choices from chances and that specifies and assigns relative values to outcomes. Sensitivity analysis allows exploration of alternative assumptions. Cost-effectiveness analysis shows the relation between dollars spent and improved health outcomes achieved. In a tutorial format, this approach is applied to the decision whether to perform coronary angiography in a patient who requires aortic valve replacement for critical aortic stenosis.

  15. Effect of indocyanine green angiography using infrared fundus camera on subsequent dark adaptation and electroretinogram.

    PubMed

    Wen, Feng; Yu, Minzhong; Wu, Dezheng; Ma, Juanmei; Wu, Lezheng

    2002-07-01

    To observe the effect of indocyanine green angiography (ICGA) with infrared fundus camera on subsequent dark adaptation and the Ganzfeld electroretinogram (ERG), the ERGs of 38 eyes with different retinal diseases were recorded before and after ICGA during a 40-min dark adaptation period. ICGA was performed with Topcon 50IA retina camera. Ganzfeld ERG was recorded with Neuropack II evoked response recorder. The results showed that ICGA did not affect the latencies and the amplitudes in ERG of rod response, cone response and mixed maximum response (p>0.05). It suggests that ICGA using infrared fundus camera could be performed prior to the recording of the Ganzfeld ERG.

  16. Use of spiral computed tomographic angiography in monitoring abdominal aortic aneurysms after transfemoral endovascular repair.

    PubMed Central

    Balm, R; Jacobs, M J

    1997-01-01

    Transfemoral endovascular repair of abdominal aortic aneurysms has proved to be technically feasible in a selected group of patients. However, long-term efficacy has not been proved. Graft performance after implantation can be monitored by a single imaging technique: spiral computed tomographic angiography. With this technique, the parameters for continuing clinical success of the procedure-graft patency, endoleaks, graft migration, attachment site diameter, attachment system failure, and aneurysm diameter-can be monitored. Only in selected cases will an additional imaging technique be necessary. PMID:9339508

  17. Pseudoaneurysm of the Superficial Femoral Artery in Behcet's Disease with Spontaneous Thrombosis Followed by CT Angiography

    SciTech Connect

    Yoshida, Satoru; Akiba, Hidenari; Tamakawa, Mituharu; Takeda, Miki; Yama, Naoya; Hareyama, Masato; Morita, Kazuo; Masuda, Atsushi; Shimamoto, Kazuaki

    1998-07-15

    A 25-year-old man developed sudden pain and a pulsating mass in the left thigh. A diagnosis of Behcet's disease was made because of four major symptoms. Laboratory data indicated active inflammation. Emergency spiral computed tomographic angiography (CTA) showed an aneurysm of the left superficial femoral artery (SFA). Under steroid therapy, follow-up spiral CTA showed spontaneous occlusion of the aneurysm. In the active phase of arteritis, spiral CTA is useful for the diagnosis of arterial lesions to avoid the arterial puncture of conventional arteriography.

  18. CT pulmonary angiography of adult pulmonary vascular diseases: Technical considerations and interpretive pitfalls.

    PubMed

    Taslakian, Bedros; Latson, Larry A; Truong, Mylene T; Aaltonen, Eric; Shiau, Maria C; Girvin, Francis; Alpert, Jeffrey B; Wickstrom, Maj; Ko, Jane P

    2016-11-01

    Computed tomography pulmonary angiography (CTPA) has become the primary imaging modality for evaluating the pulmonary arteries. Although pulmonary embolism is the primary indication for CTPA, various pulmonary vascular abnormalities can be detected in adults. Knowledge of these disease entities and understanding technical pitfalls that can occur when performing CTPA are essential to enable accurate diagnosis and allow timely management. This review will cover a spectrum of acquired abnormalities including pulmonary embolism due to thrombus and foreign bodies, primary and metastatic tumor involving the pulmonary arteries, pulmonary hypertension, as well as pulmonary artery aneurysms and stenoses. Additionally, methods to overcome technical pitfalls and interventional treatment options will be addressed.

  19. Digital subtraction angiography of the pulmonary arteries for the diagnosis of pulmonary embolism

    SciTech Connect

    Ludwig, J.W.; Verhoeven, L.A.J.; Kersbergen, J.J.; Overtoom, T.T.C.

    1983-06-01

    A comparative study of radionuclide scanning (perfusion studies in all 18 patients and ventilation studies in 9) and digital subtraction angiography (DSA) was performed in 18 patients with suspected pulmonary thromboembolism. In 17 patients good visualization of the arteries was obtained with DSA; 10 of these patients had no pre-existing lung disease, and 7 had chronic obstructive pulmonary disease (COPD). The information provided by DSA in this small group was equal to or better than that of scintigraphy, especially in patients with COPD, and the reliability of DSA was superior to that of the radionuclide scintigraphy. Methods for preventing motion artifacts with DSA are also described.

  20. Management of Tissue Ischemia in Mastectomy Skin Flaps: Algorithm Integrating SPY Angiography and Topical Nitroglycerin

    PubMed Central

    Sanniec, Kyle; Teotia, Sumeet

    2016-01-01

    Summary: Tissue ischemia can be managed in several different ways based on the cause of the perfusion defect, including topical nitroglycerin or surgical intervention. However, there are times when tissue perfusion is questioned and clinical examination is unable to determine definitively the cause of ischemic tissue and whether it will survive. In this technique article, we describe our comprehensive algorithm for the management of tissue ischemia in mastectomy skin flaps, which can be applied to other plastic surgery procedures by integrating SPY angiography and topical nitroglycerin. PMID:27826472

  1. Visualization of an actively bleeding cortical vessel into the subdural space by CT angiography.

    PubMed

    Dalfino, John C; Boulos, Alan S

    2010-10-01

    Spontaneous subdural hematomas of arterial origin are rare with only a few published case reports in the literature. In the CT era, vessel imaging of extra-axial hematomas is not commonly performed. In this case report we present a patient with a large, spontaneous acute subdural hematoma that demonstrated active contrast extravasation from a small cortical vessel on CT angiography. During surgical evacuation the vessel was confirmed to be a small cortical artery that was bulging through the arachnoid membrane and bleeding into the subdural space. The historical, radiographic, and clinical aspects of this unusual cause of subdural hematoma are discussed.

  2. Endogenous contrast blood flow imaging in embryonic hearts using hemoglobin contrast subtraction angiography

    PubMed Central

    Deniz, Engin; Jonas, Stephan; Khokha, Mustafa; Choma, Michael A.

    2013-01-01

    The genetic basis of congenital heart disease (CHD) is yet to be defined, and the interactions between the malformed heart and biomechanical cardiac performance remain poorly understood. Functional optical imaging enables detailed biomechanical phenotyping of cardiac dysfunction in small animal models, which in turn enables specific gene-phenotype relationship. We have developed a new microangiography technique based on flow imaging using endogenous hemoglobin contrast enabling in vivo assessment and biomechanical phenotyping of Xenopus tropicalis embryonic heart. We demonstrated that hemoglobin contrast angiography can be used to quantify physiological response to treatment with well-established cardioactive drugs. PMID:22825198

  3. Integration of Three-Dimensional Rotational Angiography in Radiosurgical Treatment Planning of Cerebral Arteriovenous Malformations

    SciTech Connect

    Conti, Alfredo; Pontoriero, Antonio; Farago, Giuseppe; Midili, Federica; Siragusa, Carmelo; Granata, Francesca; Pitrone, Antonio; De Renzis, Costantino; Longo, Marcello; Tomasello, Francesco

    2011-11-01

    Purpose: Accuracy in delineating the target volume is a major issue for successful stereotactic radiosurgery for arteriovenous malformations. The aim of the present study was to describe a method to integrate three-dimensional (3D) rotational angiography ( (3DRA)) into CyberKnife treatment planning and to investigate its potential advantages compared with computed tomography angiography (CTA) and magnetic resonance angiography. Methods and Materials: A total of 20 patients with a diagnosis of cerebral arteriovenous malformation were included in the present study. All patients underwent multislice computed tomography and 3D-volumetric CTA, (3DRA), and 3D magnetic resonance angiography. The contouring of the target and critical volumes was done separately using CTA and thereafter directly using (3DRA). The composite, conjoint, and disjoint volumes were measured. Results: The use of CTA or (3DRA) resulted in significant differences in the target and critical volumes. The target volume averaged 3.49 {+-} 3.01 mL measured using CTA and 3.26 {+-} 2.93 mL measured using (3DRA), for a difference of 8% (p < .05). The conjoint and disjoint volume analysis showed an 88% volume overlap. The qualitative evaluation showed that the excess volume obtained using CTA was mostly tissue surrounding the nidus and venous structures. The mean contoured venous volume was 0.67 mL measured using CTA and 0.88 mL (range, 0.1-2.7) measured using (3DRA) (p < .05). Conclusions: (3DRA) is a volumetric angiographic study that can be integrated into computer-based treatment planning. Although whether (3DRA) provides superior accuracy has not yet been proved, its high spatial resolution is attractive and offers a superior 3D view. This allows a better 3D understanding of the target volume and distribution of the radiation doses within the volume. Additional technical efforts to improve the temporal resolution and the development of software tools aimed at improving the performance of 3D contouring

  4. Doppler variance imaging for three-dimensional retina and choroid angiography

    NASA Astrophysics Data System (ADS)

    Yu, Lingfeng; Chen, Zhongping

    2010-01-01

    We demonstrate the use of Doppler variance (standard deviation) imaging for 3-D in vivo angiography in the human eye. In addition to the regular optical Doppler tomography velocity and structural images, we use the variance of blood flow velocity to map the retina and choroid vessels. Variance imaging is subject to bulk motion artifacts as in phase-resolved Doppler imaging, and a histogram-based method is proposed for bulk-motion correction in variance imaging. Experiments were performed to demonstrate the effectiveness of the proposed method for 3-D vasculature imaging of human retina and choroid.

  5. Cerebrovascular disease: evaluation with transbrachial intraarterial digital subtraction angiography using a 4-F catheter.

    PubMed

    Hicks, M E; Kreipke, D L; Becker, G J; Edwards, M K; Holden, R W; Jackson, V P; Bendick, P J; Kuehn, D S

    1986-11-01

    Three hundred sixty-one patients underwent intraarterial digital subtraction angiography for definite or probable occlusive vascular disease of the carotid arteries. Examinations were performed with 65-cm-long, 4-F aortic catheters. A transbrachial approach was used. Images were good or excellent in nearly all cases. No postprocedural neurologic deficits or hematomas occurred. Permanent pulse deficit occurred in two patients, and temporary deficit occurred in three patients, an improvement over the frequency found in previous transbrachial series using 6-8-F catheters. While these results establish the efficacy of this technique, they also indicate a possible greater relative safety in men than in women.

  6. [Choroidal neovascularisation in a patient with choroidal osteoma visualized by OCT angiography].

    PubMed

    Mihailovic, N; Alnawaiseh, M; Merté, R-L; Eter, N

    2016-11-04

    We present the case of a 38-year-old Asian patient who reported vision loss of her left eye since 4 weeks. The funduscopy showed a choroidal tumor in the papillomacular bundle, which could be identified as a choroidal osteoma with secondary choroidal neovascularization (CNV). OCT angiography (OCT-A) detected abnormal flow in the choriocapillaris; the osteoma showed no flow in the OCT angiogram of the choroid level. Therefore, OCT-A can be a helpful adjuvant for diagnosis of CNV secondary to choroidal osteoma.

  7. Hybridization increases invasive knotweed success

    PubMed Central

    Parepa, Madalin; Fischer, Markus; Krebs, Christine; Bossdorf, Oliver

    2014-01-01

    Hybridization is one of the fundamental mechanisms by which rapid evolution can occur in exotic species. If hybrids show increased vigour, this could significantly contribute to invasion success. Here, we compared the success of the two invasive knotweeds, Fallopia japonica and F. sachalinensis, and their hybrid, F. × bohemica, in competing against experimental communities of native plants. Using plant material from multiple clones of each taxon collected across a latitudinal gradient in Central Europe, we found that knotweed hybrids performed significantly better in competition with a native community and that they more strongly reduced the growth of the native plants. One of the parental species, F. sachalinensis, regenerated significantly less well from rhizomes, and this difference disappeared if activated carbon was added to the substrate, which suggests allelopathic inhibition of F. sachalinensis regeneration by native plants. We found substantial within-taxon variation in competitive success in all knotweed taxa, but variation was generally greatest in the hybrid. Interestingly, there was also significant variation within the genetically uniform F. japonica, possibly reflecting epigenetic differences. Our study shows that invasive knotweed hybrids are indeed more competitive than their parents and that hybridization increased the invasiveness of the exotic knotweed complex. PMID:24665343

  8. Minimally invasive aortic valve surgery

    PubMed Central

    Castrovinci, Sebastiano; Emmanuel, Sam; Moscarelli, Marco; Murana, Giacomo; Caccamo, Giuseppa; Bertolino, Emanuela Clara; Nasso, Giuseppe; Speziale, Giuseppe; Fattouch, Khalil

    2016-01-01

    Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease. PMID:27582764

  9. Biological Warfare in Invasive Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alliaria petiolata (garlic mustard) is an invasive species in temperate forests throughout North America that has led to a decrease in species diversity and alterations in nutrient cycling. Garlic mustard produces an arsenal of secondary chemicals in the glucosinolate family that have strong biocid...

  10. Evolutionary origins of invasive populations

    PubMed Central

    Lee, Carol Eunmi; Gelembiuk, Gregory William

    2008-01-01

    What factors shape the evolution of invasive populations? Recent theoretical and empirical studies suggest that an evolutionary history of disturbance might be an important factor. This perspective presents hypotheses regarding the impact of disturbance on the evolution of invasive populations, based on a synthesis of the existing literature. Disturbance might select for life-history traits that are favorable for colonizing novel habitats, such as rapid population growth and persistence. Theoretical results suggest that disturbance in the form of fluctuating environments might select for organismal flexibility, or alternatively, the evolution of evolvability. Rapidly fluctuating environments might favor organismal flexibility, such as broad tolerance or plasticity. Alternatively, longer fluctuations or environmental stress might lead to the evolution of evolvability by acting on features of the mutation matrix. Once genetic variance is generated via mutations, temporally fluctuating selection across generations might promote the accumulation and maintenance of genetic variation. Deeper insights into how disturbance in native habitats affects evolutionary and physiological responses of populations would give us greater capacity to predict the populations that are most likely to tolerate or adapt to novel environments during habitat invasions. Moreover, we would gain fundamental insights into the evolutionary origins of invasive populations. PMID:25567726

  11. Invasion Percolation and Global Optimization

    NASA Astrophysics Data System (ADS)

    Barabási, Albert-László

    1996-05-01

    Invasion bond percolation (IBP) is mapped exactly into Prim's algorithm for finding the shortest spanning tree of a weighted random graph. Exploring this mapping, which is valid for arbitrary dimensions and lattices, we introduce a new IBP model that belongs to the same universality class as IBP and generates the minimal energy tree spanning the IBP cluster.

  12. What is minimally invasive dentistry?

    PubMed

    Ericson, Dan

    2004-01-01

    Minimally Invasive Dentistry is the application of "a systematic respect for the original tissue." This implies that the dental profession recognizes that an artifact is of less biological value than the original healthy tissue. Minimally invasive dentistry is a concept that can embrace all aspects of the profession. The common delineator is tissue preservation, preferably by preventing disease from occurring and intercepting its progress, but also removing and replacing with as little tissue loss as possible. It does not suggest that we make small fillings to restore incipient lesions or surgically remove impacted third molars without symptoms as routine procedures. The introduction of predictable adhesive technologies has led to a giant leap in interest in minimally invasive dentistry. The concept bridges the traditional gap between prevention and surgical procedures, which is just what dentistry needs today. The evidence-base for survival of restorations clearly indicates that restoring teeth is a temporary palliative measure that is doomed to fail if the disease that caused the condition is not addressed properly. Today, the means, motives and opportunities for minimally invasive dentistry are at hand, but incentives are definitely lacking. Patients and third parties seem to be convinced that the only things that count are replacements. Namely, they are prepared to pay for a filling but not for a procedure that can help avoid having one.

  13. Computed tomography perfusion and computed tomography angiography for prediction of clinical outcomes in ischemic stroke patients after thrombolysis

    PubMed Central

    Pan, Jia-wei; Yu, Xiang-rong; Zhou, Shu-yi; Wang, Jian-hong; Zhang, Jun; Geng, Dao-ying; Zhang, Tian-yu; Cheng, Xin; Ling, Yi-feng; Dong, Qiang

    2017-01-01

    Cerebral blood perfusion and cerebrovascular lesions are important factors that can affect the therapeutic efficacy of thrombolysis. At present, the majority of studies focus on assessing the accuracy of lesion location using imaging methods before treatment, with less attention to predictions of outcomes after thrombolysis. Thus, in the present study, we assessed the efficacy of combined computed tomography (CT) perfusion and CT angiography in predicting clinical outcomes after thrombolysis in ischemic stroke patients. The study included 52 patients who received both CT perfusion and CT angiography. Patients were grouped based on the following criteria to compare clinical outcomes: (1) thrombolytic and non-thrombolytic patients, (2) thrombolytic patients with CT angiography showing the presence or absence of a vascular stenosis, (3) thrombolytic patients with CT perfusion showing the presence or absence of hemodynamic mismatch, and (4) different CT angiography and CT perfusion results. Short-term outcome was assessed by the 24-hour National Institution of Health Stroke Scale score change. Long-term outcome was assessed by the 3-month modified Rankin Scale score. Of 52 ischemic stroke patients, 29 were treated with thrombolysis and exhibited improved short-term outcomes compared with those without thrombolysis treatment (23 patients). Patients with both vascular stenosis and blood flow mismatch (13 patients) exhibited the best short-term outcome, while there was no correlation of long-term outcome with CT angiography or CT perfusion findings. These data suggest that combined CT perfusion and CT angiography are useful for predicting short-term outcome, but not long-term outcome, after thrombolysis. PMID:28250755

  14. Improved Visualization of Intracranial Vessels with Intraoperative Coregistration of Rotational Digital Subtraction Angiography and Intraoperative 3D Ultrasound

    PubMed Central

    Podlesek, Dino; Meyer, Tobias; Morgenstern, Ute; Schackert, Gabriele; Kirsch, Matthias

    2015-01-01

    Introduction Ultrasound can visualize and update the vessel status in real time during cerebral vascular surgery. We studied the depiction of parent vessels and aneurysms with a high-resolution 3D intraoperative ultrasound imaging system during aneurysm clipping using rotational digital subtraction angiography as a reference. Methods We analyzed 3D intraoperative ultrasound in 39 patients with cerebral aneurysms to visualize the aneurysm intraoperatively and the nearby vascular tree before and after clipping. Simultaneous coregistration of preoperative subtraction angiography data with 3D intraoperative ultrasound was performed to verify the anatomical assignment. Results Intraoperative ultrasound detected 35 of 43 aneurysms (81%) in 39 patients. Thirty-nine intraoperative ultrasound measurements were matched with rotational digital subtraction angiography and were successfully reconstructed during the procedure. In 7 patients, the aneurysm was partially visualized by 3D-ioUS or was not in field of view. Post-clipping intraoperative ultrasound was obtained in 26 and successfully reconstructed in 18 patients (69%) despite clip related artefacts. The overlap between 3D-ioUS aneurysm volume and preoperative rDSA aneurysm volume resulted in a mean accuracy of 0.71 (Dice coefficient). Conclusions Intraoperative coregistration of 3D intraoperative ultrasound data with preoperative rotational digital subtraction angiography is possible with high accuracy. It allows the immediate visualization of vessels beyond the microscopic field, as well as parallel assessment of blood velocity, aneurysm and vascular tree configuration. Although spatial resolution is lower than for standard angiography, the method provides an excellent vascular overview, advantageous interpretation of 3D-ioUS and immediate intraoperative feedback of the vascular status. A prerequisite for understanding vascular intraoperative ultrasound is image quality and a successful match with preoperative

  15. Preoperative visualization of the artery of Adamkiewicz by dual-phase CT angiography in patients with aortic aneurysm.

    PubMed

    Amako, Mau; Yamamoto, Yoshiaki; Nakamura, Katsumi; Tobinaga, Satoru; Nakamura, Eiji; Hosokawa, Yukio; Ohno, Tomokazu; Akashi, Hidetoshi; Aoyagi, Shigeaki; Tanaka, Hiroyuki

    2011-01-01

    To improve our ability to visualize the Adamkiewicz artery (AKA), we developed a modified intravenous CT angiography technique, which we refer to as right atrial CT (RA-CT) angiography. In this study, AKA detection rate and visualization of the arterial continuity from the aorta to the anterior spinal cord artery (ASA) was evaluated using RA-CT angiography.We performed RA-CT angiography in 110 patients with abdominal, thoracic descending, or thoracoabdominal aortic aneurysms. In RA-CT angiography, contrast medium with a high iodine concentration (370 mg/dl) was injected twice into the right atrium at a high injection rate (8.0 ml/sec), and two CT scans, starting at 20 sec after the first injection and at 35 sec after the second injection, respectively, were performed. All CT images were obtained using an 8- or 16-detector CT scanner at a slice thickness of 0.625 mm. The AKA was defined as the largest radiculomedullary artery with a characteristic hairpin turn, and with continuity from the aorta to the ASA.The AKA with hairpin turn was detected in all patients (100%), and continuity from the aorta to the ASA was confirmed in 99 of the 110 patients (90.0%). The AKA arose between Th8 and L1 in 86 of these patients (86.8%), and originated from the left side in 71 patients (71.7%).RA-CT angiography may be useful for visualizing the AKA and the arterial continuity from the aorta to the ASA in patients with aortic aneurysm, although the use of more advanced CT machines will provide safe and easy identification of the AKA and arterial continuity with a small amount of contrast medium and a single scan.

  16. A meta-analysis of trait differences between invasive and non-invasive plant species.

    PubMed

    van Kleunen, Mark; Weber, Ewald; Fischer, Markus

    2010-02-01

    A major aim in ecology is identifying determinants of invasiveness. We performed a meta-analysis of 117 field or experimental-garden studies that measured pair-wise trait differences of a total of 125 invasive and 196 non-invasive plant species in the invasive range of the invasive species. We tested whether invasiveness is associated with performance-related traits (physiology, leaf-area allocation, shoot allocation, growth rate, size and fitness), and whether such associations depend on type of study and on biogeographical or biological factors. Overall, invasive species had significantly higher values than non-invasive species for all six trait categories. More trait differences were significant for invasive vs. native comparisons than for invasive vs. non-invasive alien comparisons. Moreover, for comparisons between invasive species and native species that themselves are invasive elsewhere, no trait differences were significant. Differences in physiology and growth rate were larger in tropical regions than in temperate regions. Trait differences did not depend on whether the invasive alien species originates from Europe, nor did they depend on the test environment. We conclude that invasive alien species had higher values for those traits related to performance than non-invasive species. This suggests that it might become possible to predict future plant invasions from species traits.

  17. Congenital solitary kidney with renovascular hypertension diagnosed by means of captopril-enhanced renography and magnetic resonance angiography.

    PubMed

    Hayashida, Mie; Watanabe, Noboru; Imamura, Hiroshi; Kumazaki, Setsuo; Kitabayashi, Hiroshi; Takahashi, Wataru; Uchikawa, Shin-Ichiro; Yazaki, Yoshikazu; Kubo, Keishi

    2005-03-01

    A 24 year-old woman had a congenital solitary kidney with renovascular hypertension due to fibromuscular dysplasia. She had been treated as having essential hypertension until she developed preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome at 28 weeks of gestation. Plasma renin activity and captopril test results did not indicate any abnormalities. However, renography revealed captopril-induced deterioration. Magnetic resonance angiography was also useful to detect renal artery stenosis. These findings were confirmed by renal angiography. After successful percutaneous transluminal renal angioplasty, her blood pressure and the pattern of captopril renography normalized.

  18. Successful carbon dioxide angiography guided endovascular thrombectomy of the superficial femoral artery in a young patient with critical limb ischemia.

    PubMed

    Giusca, Sorin; Eisele, Tom; Raupp, Dorothea; Eisenbach, Christoph; Korosoglou, Grigorios

    2017-03-01

    Currently, the treatment of thromboembolic ischemia of the lower extremities includes percutaneous rotational thrombectomy and aspiration devices. However, the standard approach for endovascular treatment requires the administration of iodine contrast agents, which is problematic in patients with pre-existing renal disease and diabetes. Herein, we describe a case of a CO2 angiography guided endovascular thrombectomy of the superficial femoral artery (SFA) in a young patient with critical limb ischemia. Mechanical thrombectomy using the Rotarex system, catheter aided aspiration and subsequent stent placement in the SFA was entirely guided using CO2 angiography.

  19. Yield of CT Pulmonary Angiography in the Emergency Department When Providers Override Evidence-based Clinical Decision Support.

    PubMed

    Yan, Zihao; Ip, Ivan K; Raja, Ali S; Gupta, Anurag; Kosowsky, Joshua M; Khorasani, Ramin

    2017-03-01

    Purpose To determine the frequency of, and yield after, provider overrides of evidence-based clinical decision support (CDS) for ordering computed tomographic (CT) pulmonary angiography in the emergency department (ED). Materials and Methods This HIPAA-compliant, institutional review board-approved study was performed at a tertiary care, academic medical center ED with approximately 60 000 annual visits and included all patients who were suspected of having pulmonary embolism (PE) and who underwent CT pulmonary angiography between January 1, 2011, and August 31, 2013. The requirement to obtain informed consent was waived. Each CT order for pulmonary angiography was exposed to CDS on the basis of the Wells criteria. For patients with a Wells score of 4 or less, CDS alerts suggested d-dimer testing because acute PE is highly unlikely in these patients if d-dimer levels are normal. The yield of CT pulmonary angiography (number of positive PE diagnoses/total number of CT pulmonary angiographic examinations) was compared in patients in whom providers overrode CDS alerts (by performing CT pulmonary angiography in patients with a Wells score ≤4 and a normal d-dimer level or no d-dimer testing) (override group) and those in whom providers followed Wells criteria (CT pulmonary angiography only in patients with Wells score >4 or ≤4 with elevated d-dimer level) (adherent group). A validated natural language processing tool identified positive PE diagnoses, with subsegmental and/or indeterminate diagnoses removed by means of chart review. Statistical analysis was performed with the χ(2) test, the Student t test, and logistic regression. Results Among 2993 CT pulmonary angiography studies in 2655 patients, 563 examinations had a Wells score of 4 or less but did not undergo d-dimer testing and 26 had a Wells score of 4 or less and had normal d-dimer levels. The yield of CT pulmonary angiography was 4.2% in the override group (25 of 589 studies, none with a normal d

  20. Subarachnoid Hemorrhage in Patients with Good Clinical Grade: Accuracy of 3.0-T MR Angiography for Detection and Characterization.

    PubMed

    Li, Minghua; Zhu, Yueqi; Song, Hongmei; Gu, Binxian; Lu, Haitao; Li, Yuehua; Tan, Huaqiao; Cheng, Yingsheng

    2017-02-23

    Purpose To evaluate the diagnostic accuracy of aneurysm detection and the fidelity of morphologic characterization of three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography at 3.0 T in patients with a Glasgow coma score of 15 and noncontrast material-enhanced computed tomography (CT) findings that showed acute nontraumatic subarachnoid hemorrhage. Materials and Methods The institutional review board approved this prospective study, and patients provided informed consent. A total of 277 patients who had not experienced trauma but in whom nonenhanced CT showed subarachnoid hemorrhage, who had a Glasgow coma score of 15, and who underwent both 3D TOF MR angiography and digital subtraction angiography (DSA) (the reference standard) were included. Three observers who were blinded to clinical and DSA results independently analyzed all 3D TOF MR angiographic data sets. The receiver operating characteristic curve was applied to analysis of the detection of aneurysms with 3D TOF MR angiography by using patient- and aneurysm-based evaluations. Multivariate logistic regression analysis was performed to identify aneurysm-specific variables, including size, shape (daughter sac/lobulation/margin), neck width (wide if > 4 mm or if fundus-to-neck ratio was < 2), and relation to adjacent artery, that significantly affected morphologic assessment with 3D TOF MR angiography. Results Aneurysms were depicted with DSA in 225 patients. In patient- and aneurysm-based evaluations, respectively, 3D TOF MR angiography yielded accuracies of 96.8% (268 of 277) and 96.6% (309 of 320), sensitivities of 98.2% (219 of 223) and 98.1% (260 of 265), specificities of 91% (49 of 54) and 89% (49 of 55), positive predictive values of 97.8% (219 of 224) and 97.7% (260 of 266), and negative predictive values of 92% (49 of 53) and 91% (49 of 54). Accuracy of display of morphologic features was 92.5% (236 of 255) for size, 86.3% (220 of 255) for neck width, 94.5% for shape (241 of

  1. 2D Rotational Angiography for Fast and Standardized Evaluation of Peripheral and Visceral Artery Stenoses

    SciTech Connect

    Katoh, Marcus Opitz, Armin; Minko, Peter; Massmann, Alexander; Berlich, Joachim; Buecker, Arno

    2011-06-15

    Purpose: To investigate the value of rotational digital subtraction angiography (rDSA) for evaluation of peripheral and visceral artery stenoses compared to conventional digital subtraction angiography (cDSA). Methods: A phantom study was performed comparing the radiation dose of cDSA with two projections and rDSA by means of the 2D Dynavision technique (Siemens Medical Solutions, Forchheim, Germany). Subsequently, 33 consecutive patients (18 women, 15 men; mean {+-} SD age 67 {+-} 15 years) were examined by both techniques. In total, 63 vessel segments were analyzed by two observers with respect to stenoses, image contrast, and vessel sharpness. Results: Radiation dose was significantly lower with rDSA. cDSA and rDSA revealed 21 and 24 flow-relevant stenotic lesions and vessel occlusions (70-100%), respectively. The same stenosis grade was assessed in 45 segments. By means of rDSA, 10 lesions were judged to have a higher and 8 lesions a lower stenosis grade compared to cDSA. rDSA yielded additive information regarding the vessel anatomy and pathology in 29 segments. However, a tendency toward better image quality and sharper vessel visualization was seen with cDSA. Conclusion: rDSA allows for multiprojection assessment of peripheral and visceral arteries and provides additional clinically relevant information after a single bolus of contrast medium. At the same time, radiation dose can be significantly reduced compared to cDSA.

  2. MR Angiography of the Lower Extremities with a Moving-Bed Infusion-Tracking Technique

    SciTech Connect

    Klein, W.M.; Schlejen, P.M.; Eikelboom, B.C.; Graaf, Y. van der; Mali, W.P.T.M.

    2003-02-15

    Purpose: To assess the value of MR angiography (MRA) with automatic table movement in a consecutive series of patients with peripheral arterial disease. Methods: Seventy-two patients underwent both conventional angiography (CA) and MRA for peripheral arterial occlusive disease. Both techniques were scored in a masked way. Consensus scoring for CA was compared with MRA scoring per observer. If there was a discrepancy in scoring of asegment on MRA and CA, the images were reviewed and a consensus arrived at. Results: Observer A found 7.4% and observer B found 6.5% of the segments could not be analyzed on MRA. Observer A scored 11.4% dissimilar on MRA and CA, observer B 15.2%. In the aortoiliacarteries, this was mainly caused by stents and overestimation of stenoses; in the crural arteries it resulted from underestimation of the stenoses on MRA. Overall sensitivity and specificity for the aortoiliac, femoropopliteal and crural vessels were respectively 90% and 91%, 90% and 96%, 59% and 96% for observer A, and 85% and 91%, 84% and 89%, 68% and 85% for observer B. Conclusion: Although MRA of the lower extremities is a promising technique, improvements still need to be made. In particular, MRA below the knee is suboptimal for clinical use.

  3. Postprocessing techniques for gadolinium-enhanced three-dimensional MR angiography.

    PubMed

    Davis, C P; Hany, T F; Wildermuth, S; Schmidt, M; Debatin, J F

    1997-01-01

    Contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography is rapidly gaining acceptance as a versatile noninvasive alternative to conventional angiography. The technique has proved useful in the visualization and assessment of complex pathologic entities in the thoracic and abdominal aorta, renal arteries, pelvic arterial system, and pulmonary arteries. Several postprocessing techniques are available for reformation of the imaging data, including maximum intensity projection (MIP), surface rendering, and virtual intraluminal endoscopy (VIE). MIP and subvolume MIP reconstructions can be produced quickly and are useful for demonstration and archiving purposes. Because of its unique ability to display vessels without overlap, surface rendering is especially useful in depicting diseases that influence either the outer shape of the vessels or their topographic arrangement. VIE allows assessment of the inside of the vascular wall and is helpful in detecting wall-bound thrombus and evaluating the degree of stenosis. Most clinically relevant questions (eg, presence of pulmonary embolism, aortic aneurysm, renal artery stenosis) can be fully answered if analysis is based on MIP and thin multiplanar reformations of contrast-enhanced 3D MR angiograms. In some cases, the use of additional postprocessing techniques enhances diagnostic confidence.

  4. Enhanced Magnification Angiography Using 20-μm-Focus Tungsten Tube

    NASA Astrophysics Data System (ADS)

    Enomoto, Toshiyuki; Sato, Eiichi; Sumiyama, Yoshinobu; Aizawa, Katsuo; Watanabe, Manabu; Tanaka, Etsuro; Mori, Hidezo; Kawakami, Hiroki; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Sato, Shigehiro

    2006-10-01

    A microfocus X-ray tube is useful for performing magnification radiography, and its X-ray generator (L9631, Hamamatsu Photonics) consists of a personal computer for controlling the tube voltage and current, and a main unit with a high-voltage circuit and a fixed-anode X-ray tube. The maximum tube voltage, current, and electric power were 110 kV, 800 μA, and 50 W, respectively. The focal-spot size was proportional to the electric power of the tube, and the size was approximately 20 μm with a power of 20 W. Using a 3-mm-thick aluminum filter, the X-ray intensity was 7.75 μGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 100 μA. Because the peak photon energy was approximately 38 keV using the filter with a tube voltage of 60 kV, the bremsstrahlung X-rays were absorbed effectively by iodine-based contrast media at an iodine K-edge of 33.2 keV. Enhanced angiography was performed by fourfold magnification imaging with a computed radiography system using iodine-based microspheres 15 μm in diameter. In the angiography of nonliving animals, we observed fine blood vessels of approximately 100 μm with high contrast.

  5. A case report of segmental arterial mediolysis in which computed tomography angiography was useful for diagnosis.

    PubMed

    Yoshida, Haruka; Ukai, Katsuaki; Sugimura, Mikako; Akoshima, Hiromichi; Kimura, Kenji; Iwabuchi, Masahiro; Tadokoro, Keiichi; Takahashi, Hiroki; Rikimaru, Hiroya; Saitoh, Toshihiro; Suzuki, Hiroyoshi

    2013-12-01

    A 48-year-old male presented to our hospital with abdominal pain. Laboratory studies showed no abnormality, the severity of his abdominal pain decreased, and the patient was discharged. Five days later, the patient visited a neighborhood clinic because of fever with a 3-day history of temperatures of approximately 38 °C. The patient was admitted to our hospital 6 days after his initial visit. Laboratory investigation revealed a C-reactive protein level of 18.2 mg/dL. Abdominal computed tomography (CT) showed an 80 × 60 mm hematoma behind the descending colon, but no extravasation was detected. Thin-slice maximum-intensity-projection images from CT angiography (CTA) showed irregular narrowing and intermittent fusiform dilatations of the left colonic artery, suggesting a vascular disease, such as segmental arterial mediolysis (SAM). Digital subtraction angiography showed local irregularity, and 'beading and narrowing' of the left colonic artery, similar to the findings on CTA. Left hemicolectomy was electively performed on the twenty-fifth hospital day. Histological findings were consistent with SAM. Thus, CTA was a useful modality for the early diagnosis of SAM.

  6. Assessment of free microvascular flap perfusion by intraoperative fluorescence angiography in craniomaxillofacial surgery.

    PubMed

    Preidl, Raimund H M; Schlittenbauer, Tilo; Weber, Manuel; Neukam, Friedrich W; Wehrhan, Falk

    2015-06-01

    Microsurgical tissue transfer represents a standard technique for reconstruction in craniomaxillofacial surgery. The transferred tissue is anastomosed to vessels of varying diameters and different physiological conditions. The aim of this study was to evaluate the blood flow in free flaps at their origin and compare this with the flow after reperfusion. In 24 patients undergoing microsurgical procedures (13 radial forearm free flaps (RFFF) and 11 parascapular/scapular free flaps (PSFF)), blood flow was evaluated by intraoperative fluorescence angiography after flap raising and again after reperfusion in the neck area (Flow800, Carl Zeiss AG, Oberkochen, Germany). Flow is expressed by the blood flow index (BFI), maximum intensity (MaxInt) and half-time to MaxInt (t1/2) and was measured in the flap pedicle itself, as well as in the supplying vessels. Following anastomosis of the free flaps in the head and neck area, both the arterial and the venous BFI and MaxInt significantly increased, whereas t1/2 decreased significantly. There was no significant difference in the perfusion parameters between RFFF and PSFF. Intraoperative fluorescence angiography is a reliable method for assessing the perfusion of free microvascular flaps. In the head and neck area, free flaps undergo a significant increase in perfusion but show no differences between varying flap types.

  7. In vivo flow cytometry and time-resolved near-IR angiography and lymphography

    NASA Astrophysics Data System (ADS)

    Galanzha, Ekaterina I.; Tuchin, Valery V.; Brock, Robert W.; Zharov, Vladimir P.

    2007-05-01

    Integration of photoacoustic and photothermal techniques with high-speed, high-resolution transmission and fluorescence microscopy shows great potential for in vivo flow cytometry and indocyanine green (ICG) near-infrared (IR) angiography of blood and lymph microvessels. In particular, the capabilities of in vivo flow cytometry using rat mesentery and nude mouse ear models are demonstrated for real-time quantitative detection of circulating and migrating individual blood and cancer cells in skin, mesentery, lymph nodes, liver, kidney; studying vascular dynamics with a focus on lymphatics; monitoring cell traffic between blood and lymph systems; high-speed imaging of cell deformability in flow; and label-free real-time monitoring of single cell extravasation from blood vessel lumen into tissue. As presented, the advantages of ICG IR-angiography include estimation of time resolved dye dynamics (appearance and clearance) in blood and lymph microvessels using fluorescent and photoacoustic modules of the integrated technique. These new approaches are important for monitoring and quantifying metastatic and apoptotic cells; comparative measurements of plasma and cell velocities; analysis of immune responses; monitoring of circulating macromolecules, chylomicrons, bacteria, viruses and nanoparticles; molecular imaging. In the future, we believe that the integrated technique presented will have great potential for translation to early disease diagnoses (e.g. cancer) or assessment of innovative therapeutic interventions in humans.

  8. Surface and interfacial engineering of iron oxide nanoplates for highly efficient magnetic resonance angiography.

    PubMed

    Zhou, Zijian; Wu, Changqiang; Liu, Hanyu; Zhu, Xianglong; Zhao, Zhenghuan; Wang, Lirong; Xu, Ye; Ai, Hua; Gao, Jinhao

    2015-03-24

    Magnetic resonance angiography using gadolinium-based molecular contrast agents suffers from short diagnostic window, relatively low resolution and risk of toxicity. Taking into account the chemical exchange between metal centers and surrounding protons, magnetic nanoparticles with suitable surface and interfacial features may serve as alternative T1 contrast agents. Herein, we report the engineering on surface structure of iron oxide nanoplates to boost T1 contrast ability through synergistic effects between exposed metal-rich Fe3O4(100) facets and embedded Gd2O3 clusters. The nanoplates show prominent T1 contrast in a wide range of magnetic fields with an ultrahigh r1 value up to 61.5 mM(-1) s(-1). Moreover, engineering on nanobio interface through zwitterionic molecules adjusts the in vivo behaviors of nanoplates for highly efficient magnetic resonance angiography with steady-state acquisition window, superhigh resolution in vascular details, and low toxicity. This study provides a powerful tool for sophisticated design of MRI contrast agents for diverse use in bioimaging applications.

  9. Optical coherence tomography angiography in paracentral acute middle maculopathy secondary to central retinal vein occlusion.

    PubMed

    Casalino, G; Williams, M; McAvoy, C; Bandello, F; Chakravarthy, U

    2016-06-01

    PurposeTo report the clinical course and the optical coherence tomography angiography (OCTA) findings of patients presenting with paracentral acute middle maculopathy (PAMM) and central retinal vein occlusion (CRVO).MethodsRetrospective case series. Clincal records and multimodal imaging findings of patients presenting with PAMM and CRVO were reviewed.ResultsThree eyes of three patients (2 males; mean age: 66 years) were included in the study. Mean follow-up was 9 months and images using OCTA (AngioVue OCT angiography system, Optovue, Inc., Fremont, CA, USA) were available at the last follow-up visit. During follow-up, best corrected visual acuity (BCVA) of case 1 was unchanged at 85 ETDRS letters and OCTA revealed a mild attenuation of the perifoveal deep capillary plexus (DCP); in case 2, BCVA changed from 83 to 77 ETDRS letters and OCTA revealed patchy areas of attenuation and pruning of the DCP; in case 3, BCVA decreased from 26 to 8 ETDRS letters and OCTA revealed extensive areas of DCP dropout.ConclusionThe natural course of visual acuity in patients with PAMM secondary to CRVO may vary. In these patients, the extent of DCP dropout on OCTA may reflect the extent of visual acuity impairment.

  10. Computer Simulation of Magnetic Resonance Angiography Imaging: Model Description and Validation

    PubMed Central

    Klepaczko, Artur; Szczypiński, Piotr; Dwojakowski, Grzegorz; Strzelecki, Michał; Materka, Andrzej

    2014-01-01

    With the development of medical imaging modalities and image processing algorithms, there arises a need for methods of their comprehensive quantitative evaluation. In particular, this concerns the algorithms for vessel tracking and segmentation in magnetic resonance angiography images. The problem can be approached by using synthetic images, where true geometry of vessels is known. This paper presents a framework for computer modeling of MRA imaging and the results of its validation. A new model incorporates blood flow simulation within MR signal computation kernel. The proposed solution is unique, especially with respect to the interface between flow and image formation processes. Furthermore it utilizes the concept of particle tracing. The particles reflect the flow of fluid they are immersed in and they are assigned magnetization vectors with temporal evolution controlled by MR physics. Such an approach ensures flexibility as the designed simulator is able to reconstruct flow profiles of any type. The proposed model is validated in a series of experiments with physical and digital flow phantoms. The synthesized 3D images contain various features (including artifacts) characteristic for the time-of-flight protocol and exhibit remarkable correlation with the data acquired in a real MR scanner. The obtained results support the primary goal of the conducted research, i.e. establishing a reference technique for a quantified validation of MR angiography image processing algorithms. PMID:24740285

  11. 3D brain MR angiography displayed by a multi-autostereoscopic screen

    NASA Astrophysics Data System (ADS)

    Magalhães, Daniel S. F.; Ribeiro, Fádua H.; Lima, Fabrício O.; Serra, Rolando L.; Moreno, Alfredo B.; Li, Li M.

    2012-02-01

    The magnetic resonance angiography (MRA) can be used to examine blood vessels in key areas of the body, including the brain. In the MRA, a powerful magnetic field, radio waves and a computer produce the detailed images. Physicians use the procedure in brain images mainly to detect atherosclerosis disease in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke and identify a small aneurysm or arteriovenous malformation inside the brain. Multi-autostereoscopic displays provide multiple views of the same scene, rather than just two, as in autostereoscopic systems. Each view is visible from a different range of positions in front of the display. This allows the viewer to move left-right in front of the display and see the correct view from any position. The use of 3D imaging in the medical field has proven to be a benefit to doctors when diagnosing patients. For different medical domains a stereoscopic display could be advantageous in terms of a better spatial understanding of anatomical structures, better perception of ambiguous anatomical structures, better performance of tasks that require high level of dexterity, increased learning performance, and improved communication with patients or between doctors. In this work we describe a multi-autostereoscopic system and how to produce 3D MRA images to be displayed with it. We show results of brain MR angiography images discussing, how a 3D visualization can help physicians to a better diagnosis.

  12. Functional Imaging of the Foot with Perfusion Angiography in Critical Limb Ischemia

    SciTech Connect

    Reekers, Jim A.; Koelemay, Mark J. W.; Marquering, Henk A. Bavel, Ed T. van

    2016-02-15

    PurposeTo report on the first clinical experience with perfusion angiography (PA) of the foot in patients with chronic critical limb ischemia.Materials and MethodsPA is a post-processing software algorithm and no extra digital subtraction angiography (DSA) has to be performed for this analysis. The data used to test the feasibility of PA were obtained from a consecutive group of 89 patients with CLI who were treated with standard below the knee angioplasty and 12 separate patients who were not suitable for endovascular revascularization.ResultsMotion artifacts in the dataset of the DSA made post-procedural analysis impossible in 10 % intervention. In the majority of patients (59/68) PA showed an increase in volume flow in the foot after successful angioplasty of the crural vessels. However, in 9/68 patients no increase was seen after successful angioplasty. With the use of a local administered competitive α-adrenergic receptor antagonist, it is also possible to test and quantify the capillary resistance index which is a parameter for the remaining functionality of the microcirculation in CLI patients.ConclusionPA might be used as a new endpoint for lower limb revascularization and can also be used to test the functionality the microcirculation to identify sub-types of patients with CLI. Clinical evaluation and standardization of PA is mandatory before introduction in daily practice.

  13. Computational hemodynamics of an implanted coronary stent based on three-dimensional cine angiography reconstruction.

    PubMed

    Chen, Mounter C Y; Lu, Po-Chien; Chen, James S Y; Hwang, Ned H C

    2005-01-01

    Coronary stents are supportive wire meshes that keep narrow coronary arteries patent, reducing the risk of restenosis. Despite the common use of coronary stents, approximately 20-35% of them fail due to restenosis. Flow phenomena adjacent to the stent may contribute to restenosis. Three-dimensional computational fluid dynamics (CFD) and reconstruction based on biplane cine angiography were used to assess coronary geometry and volumetric blood flows. A patient-specific left anterior descending (LAD) artery was reconstructed from single-plane x-ray imaging. With corresponding electrocardiographic signals, images from the same time phase were selected from the angiograms for dynamic three-dimensional reconstruction. The resultant three-dimensional LAD artery at end-diastole was adopted for detailed analysis. Both the geometries and flow fields, based on a computational model from CAE software (ANSYS and CATIA) and full three-dimensional Navier-Stroke equations in the CFD-ACE+ software, respectively, changed dramatically after stent placement. Flow fields showed a complex three-dimensional spiral motion due to arterial tortuosity. The corresponding wall shear stresses, pressure gradient, and flow field all varied significantly after stent placement. Combined angiography and CFD techniques allow more detailed investigation of flow patterns in various segments. The implanted stent(s) may be quantitatively studied from the proposed hemodynamic modeling approach.

  14. Perfusion Angiography of the Foot in Patients with Critical Limb Ischemia: Description of the Technique

    SciTech Connect

    Jens, Sjoerd Marquering, Henk A.; Koelemay, Mark J. W.; Reekers, Jim A.

    2015-02-15

    ObjectiveTo study the feasibility of 2D perfusion imaging in critical limb ischemia (CLI).Methods/ResultsPerfusion angiography is a new technology which was tested in 18 patients with CLI of the foot. A standardized protocol was used with a catheter placed at the mid-part of the popliteal artery, and a total of 9 cc of non-ionic iodinated contrast material was injected at a rate of 3 cc/sec. The technology is based on early cardiology research where iodinated contrast agents were used for imaging of cardiac perfusion. During the first pass of the contrast, there is a significant diffusion of the contrast agents into the interstitial space, particularly for non-ionic and low-molecular-weight compounds.DiscussionThe original angiography data can be used to make a time–density curve, which represents the actual perfusion of the foot in time. Angiographic perfusion imaging is a post-processing modality for which no extra contrast or radiation is needed. With this technique, it is possible to get more information about the perfusion status and microcirculation of the foot. This is a step toward functional imaging in CLI patients.

  15. Acetazolamide challenge for three-dimensional time-of-flight MR angiography of the brain

    SciTech Connect

    Mandai, Kenji; Sueyoshi, Kenji; Fukunaga, Ryuzo; Nukada, Masaru; Ohtani, Fumio; Araki, Yutaka; Tsukaguchi, Isao; Abe, Hiroshi )

    1994-04-01

    We compared three-dimensional time-of-flight MR angiograms obtained before and after acetazolamide administration to evaluate whether use of this drug could improve visualization of small peripheral intracranial arteries and atherosclerotic stenosis. For evaluation of small peripheral arteries, 10 patients with clinical diagnosis of ischemic cerebrovascular disease and 10 healthy volunteers were investigated, and for evaluation of stenosis, another 6 patients were investigated. Vascular images were obtained by three-dimensional time-of-flight MR angiography. After a baseline scan, 17 mg/kg acetazolamide was injected intravenously and the second scan was performed 20 minutes later. Several small peripheral arteries that had not been seen on the baseline images were visible on the acetazolamide images without any augmentation of the background signals. Stenotic lesions in the main trunks of the major cerebral arteries were detected more clearly on acetazolamide images. Acetazolamide improves visualization of small peripheral intracranial arteries and sensitivity in detecting atherosclerotic stenosis in the main trunk of major cerebral artery by three-dimensional time-of-flight MR angiography without changing MR apparatus and software. 15 refs., 5 figs., 2 tabs.

  16. [Capacities of angiography in the imaging of abnormal changes in the cerebral arteries].

    PubMed

    Mikhaĭlov, A N; Gonchar, A A; Karpovich, D I

    2011-01-01

    The study was based on the angiographic examination of 233 patients with prior subarachnoidal hemorrhage. Angiographic study was performed using the Seldinger technique by contrasting both carotid and vertebral arteries. Twenty-three patients in whom arterial aneurysm had been detected by digital subtraction angiography underwent 3D angiography. The authors improved a procedure during which a contrast agent was manually injected into the internal carotid or vertebral artery, by using a 20-ml disposal syringe with controlled maximum developed pressure and flow increase rate up to 2.0 ml/sec for 4-5 sec during rotary scanning and the administration of the radiocontrast medium was stopped when an image appeared on the monitor at 190 degrees (190.0, 200.0) C-arm rotation. This procedure could decrease significantly the volume of the administered contrast agent from 18 to 8 (8.0, 10.0) ml and reduce the time of radiation exposure from 6 to 4 (4.0, 5.0) sec. The improved angiographic modes for the right vertebral and right carotid artery could visualize pathological changes in these arteries and establish a relationship, namely: due to degenerative dystrophic processes of the cervical spine there is a tendency for higher pathological changes in the vertebral arteries with an increased stage of osteochondrosis in the cervical spine (R = 0.95; p = 0.014).

  17. [Digital subtraction angiography with carbon dioxide in severe arterial ischemia and allergy to iodinated compounds].

    PubMed

    Calvo Cascallo, J; Mundi Salvadó, N; Cardona Fontanet, M

    1993-01-01

    When in some selected patients, a direct arterial surgery (DAS) procedure or an endoluminal surgery (ES) are required for a chronic arterial ischemia (III or IV degrees), and an arteriography with contrast is absolutely contraindicated (because of severe renal failure without hemodialysis program or a severe congestive heart failure or a hyperthyroidism or a seriously demonstrated hypersensibility against the contrast agents); an angiography by digital subtraction with carbon dioxide (DIVAS-CO2) is indicated. This technique provides good quality images with minimal risks for the patient and an adequate study for ulterior treatment. We report a case of a 67-years-old woman, with diabetes-II, ischemic cardiopathy, arterial hypertension and a demonstrated hypersensibility against the iodide compounds. The patient was admitted because of a chronic ischemia (IV degree) with ischemic ulcerations on some fingers from the left foot. High doses of analgesic drugs were needed. Because the hypersensibility against the iodide compounds, an angiography with CO2 was carried out. The good quality images provided by this technique showed the factibility of a revascularization.

  18. A comparison of arterial closure devices to manual compression in liver transplantation candidates undergoing coronary angiography.

    PubMed

    MacDonald, Lee A; Beohar, Nirat; Wang, Norman C; Nee, Lisa; Chandwaney, Raj; Ricciardi, Mark J; Benzuly, Keith H; Meyers, Sheridan N; Gheorghiada, Mihai; Davidson, Charles J

    2003-02-01

    Whether arterial closure devices can be used safely in a coagulopathic population undergoing cardiac catheterization and at high risk for groin complications, such as liver transplant candidates, is unknown. In this prospective, non-randomized consecutive series of 80 liver transplant candidates undergoing coronary angiography, manual compression and arterial closure devices were compared. Ilio-femoral angiography was performed to determine suitability for use of the closure device. Bleeding and vascular complications were recorded along with time to ambulation. Arterial closure devices were used in 31 patients (39%), whereas manual compression was used in 49 patients (50 procedures) (61%). There were no significant differences between the two groups with respect to age, sex, cardiac risk factors, peripheral vascular disease, baseline platelet count or baseline INR. There were 10 total vascular complications out of 50 procedures (20%) in the manual compression group compared to 2 vascular complications out of 31 procedures in the arterial closure device group (6%; p = 0.12). The time to ambulation was significantly less in the group receiving arterial closure devices versus manual compression (4.2 1.8 hours versus 6.6 3.7 hours, respectively; p = 0.0003). In coagulopathic patients at higher risk for groin complications, arterial closure devices can be safely used and decrease time to ambulation compared to manual compression.

  19. Intravenous coronary angiography utilizing K-emission and bremsstrahlung X-rays produced by electron bombardment

    SciTech Connect

    1992-12-31

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with synchrotron radiation at SSRL and NSLS have shown that such an intravenous angiography procedure would be possible with an intense source of monochromatic X-rays. Because of the high cost of an electron synchrotron, theoretical analysis and experiments using inanimate phantoms has been undertaken to demonstrate the feasibility of using the spectrum produced by two appropriately chosen anode materials when bombarded with electrons in the 100--500 keV energy range for angiography. By using the X-rays emitted at 120{degree} to the incident electron direction, about 20--30% of the X-ray intensity would be due to K-emission lines. Calculations using the TIGERP Monte Carlo Code, have shown that high quality angiograms of human coronary arteries should be possible with a contrast agent containing ytterbium, if an electron beam pulses of 16 kJ were used for each anode target. The experimental program supported in part by the DOE has consisted of these theoretical calculations and experiments at the Dynamitron Electron Accelerator Facility at BNL.

  20. Use of Dyna-CT Angiography in Neuroendovascular Decision-Making

    PubMed Central

    Namba, K.; Niimi, Y.; Song, J.K.; Berenstein, A.

    2009-01-01

    Summary A successful neuroendovascular procedure depends on accurate anatomical understanding of a target vessel in relation to surrounding anatomical structures or endovascular devices, such as coils and stents. During an endovascular procedure, with conventional or three dimensional (3D) rotational angiography, this type of information is extremely difficult to obtain in a timely manner. To overcome this drawback, a DynaCT was combined with low dose con