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Sample records for diabedes randomized angiography

  1. Cerebral angiography

    MedlinePlus

    ... Carotid angiogram; Cervicocerebral catheter-based angiography; Intra-arterial digital subtraction angiography; IADSA ... with the dye are seen. This is called digital subtraction angiography (DSA). After the x-rays are ...

  2. Comparison of Iohexol-380 and Iohexol-350 for Coronary CT Angiography: A Multicenter, Randomized, Double-Blind Phase 3 Trial

    PubMed Central

    Park, Eun-Ah; Kang, Doo Kyoung; Kim, Sung Jin; Kim, Young-Ju; Kim, Yookyung; Sung, Yon Mi; Song, Soon-Young; Oh, Yu-Whan; Yong, Hwan Seok; Lee, Heon; Jeon, Eui-Yong; Jin, Gong-Yong; Choi, Byoung Wook; Choi, Sang-Il

    2016-01-01

    Objective This multi-center, randomized, double-blind, phase 3 trial was conducted to compare the safety and efficacy of contrast agents iohexol-380 and iohexol-350 for coronary CT angiography in healthy subjects. Materials and Methods Volunteers were randomized to receive 420 mgI/kg of either iohexol-350 or iohexol-380 using a flow rate of 4 mL/sec. All adverse events were recorded. Two blinded readers independently reviewed the CT images and conflicting results were resolved by a third reader. Luminal attenuations (ascending aorta, left main coronary artery, and left ventricle) in Hounsfield units (HUs) and image quality on a 4-point scale were calculated. Results A total of 225 subjects were given contrast media (115 with iohexol-380 and 110 with iohexol-350). There was no difference in number of adverse drug reactions between groups: 75 events in 56 (48.7%) of 115 subjects in the iohexol-380 group vs. 74 events in 51 (46.4%) of 110 subjects in the iohexol-350 group (p = 0.690). No severe adverse drug reactions were recorded. Neither group showed an increase in serum creatinine. Significant differences in mean density between the groups was found in the ascending aorta: 375.8 ± 71.4 HU with iohexol-380 vs. 356.3 ± 61.5 HU with iohexol-350 (p = 0.030). No significant differences in image quality scores between both groups were observed for all three anatomic evaluations (all, p > 0.05). Conclusion Iohexol-380 provides improved enhancement of the ascending aorta and similar attenuation of the coronary arteries without any increase in adverse drug reactions, as compared with iohexol-350 using an identical amount of total iodine. PMID:27134522

  3. Fluorescein angiography

    MedlinePlus

    ... abnormal vessels, and there are no blockages or leakages. ... If blockage or leakage is present, the pictures will map the location for possible treatment. An abnormal value on a fluorescein angiography may ...

  4. The Impact of Remote Ischemic Pre-Conditioning on Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography and Angioplasty: A Double-Blind Randomized Clinical Trial

    PubMed Central

    Gholoobi, Arash; Sajjadi, Seyyed Masoud; Shabestari, Mahmoud Mohammadzadeh; Eshraghi, Ali; Shamloo, Alireza Sepehri

    2015-01-01

    Background and objective Contrast-induced nephropathy (CIN) is an acute major complication following intravascular administration of iodinated contrast agents; however, the best approach for preventing CIN is not clear. Remote ischemic pre-conditioning (RIPC) is a new, non-pharmacological method that has been considered for the prevention of CIN following coronary angiography. This study assessed the effects of RIPC with four brief episodes of upper limb ischemia and reperfusion in the prevention of contrast-induced nephropathy (CIN) after coronary angiography and/or angioplasty. Methods In this double-blind randomized clinical trial, we enrolled 51 patients with chronic stable angina and non-ST elevation acute coronary syndrome (NSTE.ACS), and they underwent coronary angiography and/or angioplasty. Standard fluid therapy with normal saline was prescribed for all patients before and after the procedure. The patients were divided into two groups, i.e., a study group of patients who had undergone RIPC intervention and a control group of patients who had not undergone RIPC. One hour before the procedure, a sphygmomanometer cuff was placed around one arm and inflated up to 50 mmHg above the systolic pressure for five minutes; then, the cuff was deflated for another five minutes, and this cycle was repeated four times. The patients’ serum creatinine levels were measured at baseline and 48 hours after the procedure, and the incidence of CIN was calculated. Results Twenty-one males and 30 females were studied in two groups, i.e., an RIPC intervention group (n = 25) and a control group (n = 26) that were homogenous considering baseline characteristics. No significant difference was observed in the mean level of serum creatinine between the two groups at a post-intervention time of 48 hours (RICP: 1.74 ± 0.70 mg/dL vs. Control: 1.75 ± 0.87 mg/dL; P = 0.64). However, a lower incidence rate of CIN was observed 48 hours after the administration of the contrast medium in

  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. Iodixanol Has a Favourable Fibrinolytic Profile Compared to Iohexol in Cardiac Patients Undergoing Elective Angiography: A Double-Blind, Randomized, Parallel Group Study

    PubMed Central

    Treweeke, Andrew T.; Maskrey, Benjamin H.; Hickson, Kirsty; Miller, John H.; Leslie, Stephen J.; Megson, Ian L.

    2016-01-01

    Background There is no consensus and a limited evidence base for choice of contrast agents (CA) in angiography. This study evaluated the impact of iohexol and iodixanol CA on fibrinolytic factors (tissue plasminogen activator [t-PA] and plasminogen activator inhibitor-1 [PAI-1]), as well as platelet-monocyte conjugates in cardiac patients undergoing elective angiography in a double-blind, randomised parallel group study. Methods Patients (men, 50–70 years old; n = 12) were randomised to receive either iohexol (Omnipaque; n = 6) or iodixanol (Visipaque; n = 6) during elective angiography at Raigmore Hospital, Inverness, UK. Arterial and venous blood samples were drawn prior to CA delivery and following angiography. Assessment of platelet-monocyte conjugation, t-PA and PAI-1 antigen and activity was conducted in samples pre- and post-angiography. Outcome Plasma t-PA antigen was depressed equally in the study groups after angiography, but there was a greater reduction in PAI-1 antigen in the group receiving iodixanol. These findings corresponded to a substantial reduction in t-PA activity in patients receiving iohexol, with no change in those receiving iodixanol (P = 0.023 between the CA groups). Both CAs caused a reduction in platelet-monocyte conjugation, with no difference between the groups. No adverse events were reported during the trial. Conclusion Avoiding reduced plasma t-PA activity might be an important consideration in choosing iodixanol over iohexol in patients at risk of thrombosis following angiography. The trial is registered on the ISRCTN register (ISRCTN51509735) and funded by the Coronary Thrombosis Trust and National Health Service (Highland) R&D Endowments. The funders had no influence over study design or reporting. Trial Registration Controlled-Trials.com ISRCTN51509735 PMID:26784323

  7. Fractional flow reserve versus angiography in guiding management to optimize outcomes in non–ST-elevation myocardial infarction (FAMOUS-NSTEMI): Rationale and design of a randomized controlled clinical trial☆

    PubMed Central

    Berry, Colin; Layland, Jamie; Sood, Arvind; Curzen, Nick P.; Balachandran, Kanarath P.; Das, Raj; Junejo, Shahid; Henderson, Robert A.; Briggs, Andrew H.; Ford, Ian; Oldroyd, Keith G.

    2013-01-01

    Background In patients with acute non–ST-elevation myocardial infarction (NSTEMI), coronary arteriography is usually recommended; but visual interpretation of the angiogram is subjective. We hypothesized that functional assessment of coronary stenosis severity with a pressure-sensitive guide wire (fractional flow reserve [FFR]) would have additive diagnostic, clinical, and health economic utility as compared with angiography-guided standard care. Methods and design A prospective multicenter parallel-group 1:1 randomized controlled superiority trial in 350 NSTEMI patients with ≥1 coronary stenosis ≥30% severity (threshold for FFR measurement) will be conducted. Patients will be randomized immediately after coronary angiography to the FFR-guided group or angiography-guided group. All patients will then undergo FFR measurement in all vessels with a coronary stenosis ≥30% severity including culprit and nonculprit lesions. Fractional flow reserve will be disclosed to guide treatment in the FFR-guided group but not disclosed in the “angiography-guided” group. In the FFR-guided group, an FFR ≤0.80 will be an indication for revascularization by percutaneous coronary intervention or coronary artery bypass surgery, as appropriate. The primary outcome is the between-group difference in the proportion of patients allocated to medical management only compared with revascularization. Secondary outcomes include the occurrence of cardiac death or hospitalization for myocardial infarction or heart failure, quality of life, and health care costs. The minimum and average follow-up periods for the primary analysis are 6 and 18 months, respectively. Conclusions Our developmental clinical trial will address the feasibility of FFR measurement in NSTEMI and the influence of FFR disclosure on treatment decisions and health and economic outcomes. PMID:24093845

  8. Is Coronary Computed Tomography Angiography a Resource Sparing Strategy in the Risk Stratification and Evaluation of Acute Chest Pain? Results of a Randomized Controlled Trial

    PubMed Central

    Miller, Adam H.; Pepe, Paul E.; Peshock, Ron; Bhore, Rafia; Yancy, Clyde C.; Xuan, Lei; Miller, Margarita M.; Huet, Gisselle R.; Trimmer, Clayton; Davis, Rene; Chason, Rebecca; Kashner, Micheal T.

    2011-01-01

    Objectives Annually, almost 6 million U.S. citizens are evaluated for acute chest pain syndromes (ACPSs), and billions of dollars in resources are utilized. A large part of the resource utilization results from precautionary hospitalizations that occur because care providers are unable to exclude the presence of coronary artery disease (CAD) as the underlying cause of ACPSs. The purpose of this study was to examine whether the addition of coronary computerized tomography angiography (CCTA) to the concurrent standard care (SC) during an index emergency department (ED) visit could lower resource utilization when evaluating for the presence of CAD. Methods Sixty participants were assigned randomly to SC or SC + CCTA groups. Participants were interviewed at the index ED visit and at 90 days. Data collected included demographics, perceptions of the value of accessing health care, and clinical outcomes. Resource utilization included services received from both the primary in-network and the primary out-of-network providers. The prospectively defined primary endpoint was the total amount of resources utilized over a 90-day follow-up period when adding CCTA to the SC risk stratification in ACPSs. Results The mean (± standard deviation [SD]) for total resources utilized at 90 days for in-network plus out-of-network services was less for the participants in the SC + CCTA group ($10,134; SD ± $14,239) versus the SC-only group ($16,579; SD ± $19,148; p = 0.144), as was the median for the SC + CCTA ($4,288) versus SC only ($12,148; p = 0.652; median difference = −$1,291; 95% confidence interval [CI] = −$12,219 to $1,100; p = 0.652). Among the 60 total study patients, only 19 had an established diagnosis of CAD at 90 days. However, 18 (95%) of these diagnosed participants were in the SC + CCTA group. In addition, there were fewer hospital readmissions in the SC + CCTA group (6 of 30 [20%] vs. 16 of 30 [53%]; difference in proportions = −33%; 95% CI = −56% to −10%; p

  9. 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 ...

  10. Fluorescein angiography printouts.

    PubMed

    Merin, L M

    1980-04-01

    Nineteen years after the pioneering efforts of Novotny and Alvis, fluorescein angiography has reached a level of acceptance and use which reflects its high value in ophthalmic diagnosis. Angiography laboratories are commonplace in hospitals, and many private physicians own fundus cameras and perform fluorescein angiograms routinely. As the use of this test has substantially increased, so has the number of methods used to present the film for analysis and interpretation. At this writing there are no fewer than 12 different ways of presenting fluorescein angiograms in common use (Table 1). Not all of these techniques are able to yield equal amounts of information, however, and as consultations between different laboratories occur, much difficulty results from the disparate styles. Evaluation of these varying techniques of fluorescein angiography presentation depends on the production complexity and the amount of useful information which each may yield. PMID:7235472

  11. CT angiography - head and neck

    MedlinePlus

    Computed tomography angiography - brain; CTA - skull; CTA - cranial; TIA-CTA head; Stroke-CTA head; Computed tomography angiography - neck; CTA - neck; Vertebral artery - CTA; Carotid artery stenosis - CTA; ...

  12. Spine MR angiography.

    PubMed

    Bowen, B C; Pattany, P M

    1997-01-01

    The use of MR angiography to evaluate spinal vessels is in an early stage of development. Both time-of-flight (3D) and phase-contrast (2D and 3D) techniques have been applied, and for both types of techniques, the vessels are best visualized following intravenous gadolinium administration. The vessels of interest are the millimeter-sized intradural arteries and veins, which are located on the cord surface and travel from the cord to the epidural space. Only the post gadolinium 3D TOF technique has been shown to display normal intradural vessels (thoracolumbar region), principally veins. Both TOF and PC techniques provide better delineation of enlarged intradural vessels associated with spinal vascular malformations than standard MR imaging alone. PC techniques are much less sensitive in detecting the arterial supply to dural arteriovenous fistula than intramedullary arteriovenous malformation. The TOF technique can predict the foraminal level of a dural fistula when an enlarged medullary vein, resulting from retrograde drainage, is present. MR angiography, in conjunction with MR imaging, is now suggested for screening of suspected spinal vascular malformation. Other applications such as vascular tumors and arterial or venous occlusive disease are under investigation.

  13. 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

  14. A comparison of iopamidol and iohexol in cerebral angiography.

    PubMed

    Pelz, D M; Fox, A J; Viñuela, F; Lylyk, P

    1988-01-01

    Iopamidol and iohexol, the new nonionic low-osmolality contrast agents, have both been shown to be safe, effective, and better tolerated than conventional ionic agents for cerebral angiography. In this randomized, double-blind study involving 40 patients, these two agents were compared for adverse effects, radiographic quality, and patient tolerance. No significant differences were observed in 220 injections. Because we found iopamidol and iohexol to be equally safe and effective for cerebral angiography, the choice of which contrast agent to use should be based on other considerations.

  15. CT angiography - abdomen and pelvis

    MedlinePlus

    Computed tomography angiography - abdomen and pelvis; CTA - abdomen and pelvis; Renal artery - CTA; Aortic - CTA; Mesenteric CTA ... belly or pelvis Masses and tumors in the abdomen or pelvis, including cancer, when needed to help ...

  16. Atrial myxomas and coronary angiography.

    PubMed

    Rafiq, Isma; Parthasarthy, H; Clark, C Grahame

    2010-07-01

    Coronary angiography is not an only important component of preoperative evaluation of the patient with underlying coronary artery disease but also diagnostic tool for delineating cardiac myxomas. This also serve as an important surgical anatomical marker. We present two cases which presented with repeated episode of chest pain, were found to have atrial blushing on coronary angiography subsequent confirmation of diagnosis of atrial myxoma on echocardiography. PMID:20578102

  17. CT Angiography after 20 Years

    PubMed Central

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

    2015-01-01

    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. PMID:24848958

  18. Stent sizing strategies in renal artery stenting: the comparison of conventional invasive renal angiography with renal computed tomographic angiography

    PubMed Central

    Michalowska, Ilona; Pregowski, Jerzy; Janaszek-Sitkowska, Hanna; Lech, Katarzyna; Kabat, Marek; Staruch, Adam; Januszewicz, Andrzej; Witkowski, Adam

    2016-01-01

    Introduction Randomized trials comparing invasive treatment of renal artery stenosis with standard pharmacotherapy did not show substantial benefit from revascularization. One of the potential reasons for that may be suboptimal procedure technique. Aim To compare renal stent sizing using two modalities: three-dimensional renal computed tomography angiography (CTA) versus conventional angiography. Material and methods Forty patients (41 renal arteries), aged 65.1 ±8.5 years, who underwent renal artery stenting with preprocedural CTA performed within 6 months, were retrospectively analyzed. In CTA analysis, reference diameter (CTA-D) and lesion length (CTA_LL) were measured and proposed stent diameter and length were recorded. Similarly, angiographic reference diameter (ANGIO_D) and lesion length (ANGIO_LL) as well as proposed stent dimensions were obtained by visual estimation. Results The median CTA_D was 0.5 mm larger than the median ANGIO_D (p < 0.001). Also, the proposed stent diameter in CTA evaluation was 0.5 mm larger than that in angiography (p < 0.0001). The median CTA_LL was 1 mm longer than the ANGIO_LL (p = NS), with significant correlation of these variables (r = 0.66, p < 0.0001). The median proposed stent length with CTA was equal to that proposed with angiography. The median diameter of the implanted stent was 0.5 mm smaller than that proposed in CTA (p < 0.0005) and identical to that proposed in angiography. The median length of the actual stent was longer than that proposed in angiography (p = 0.0001). Conclusions Renal CTA has potential advantages as a tool adjunctive to angiography in appropriate stent sizing. Careful evaluation of the available CTA scans may be beneficial and should be considered prior to the planned procedure. PMID:27279870

  19. Coronary magnetic resonance angiography.

    PubMed

    Stuber, Matthias; Weiss, Robert G

    2007-08-01

    Coronary magnetic resonance angiography (MRA) is a powerful noninvasive technique with high soft-tissue contrast for the visualization of the coronary anatomy without X-ray exposure. Due to the small dimensions and tortuous nature of the coronary arteries, a high spatial resolution and sufficient volumetric coverage have to be obtained. However, this necessitates scanning times that are typically much longer than one cardiac cycle. By collecting image data during multiple RR intervals, one can successfully acquire coronary MR angiograms. However, constant cardiac contraction and relaxation, as well as respiratory motion, adversely affect image quality. Therefore, sophisticated motion-compensation strategies are needed. Furthermore, a high contrast between the coronary arteries and the surrounding tissue is mandatory. In the present article, challenges and solutions of coronary imaging are discussed, and results obtained in both healthy and diseased states are reviewed. This includes preliminary data obtained with state-of-the-art techniques such as steady-state free precession (SSFP), whole-heart imaging, intravascular contrast agents, coronary vessel wall imaging, and high-field imaging. Simultaneously, the utility of electron beam computed tomography (EBCT) and multidetector computed tomography (MDCT) for the visualization of the coronary arteries is discussed. PMID:17610288

  20. 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

  1. Pulmonary Thromboembolism: Evaluation By Intravenous Angiography

    NASA Astrophysics Data System (ADS)

    Pond, Gerald D.; Cook, Glenn C.; Woolfenden, James M.; Dodge, Russell R.

    1981-11-01

    Using perfusion lung scans as a guide, digital video subtraction angiography of the pulmonary arteries was performed in human subjects suspected of having pulmonary embolism. Dogs were employed as a pulmonary embolism model and both routine pulmonary angiography and intravenous pulmonary angiograms were obtained for comparison purposes. We have shown by our preliminary results that the technique is extremely promising as a safe and accurate alternative to routine pulmonary angiography in selected patients.

  2. Coronary Computed Tomography Angiography in the Assessment of Acute Chest Pain in the Emergency Room

    PubMed Central

    dos Prazeres, Carlos Eduardo Elias; Cury, Roberto Caldeira; Carneiro, Adriano Camargo de Castro; Rochitte, Carlos Eduardo

    2013-01-01

    The coronary computed tomography angiography has recently emerged as an accurate diagnostic tool in the evaluation of coronary artery disease, providing diagnostic and prognostic data that correlate directly with the data provided by invasive coronary angiography. The association of recent technological developments has allowed improved temporal resolution and better spatial coverage of the cardiac volume with significant reduction in radiation dose, and with the crucial need for more effective protocols of risk stratification of patients with chest pain in the emergency room, recent evaluation of the computed tomography coronary angiography has been performed in the setting of acute chest pain, as about two thirds of invasive coronary angiographies show no significantly obstructive coronary artery disease. In daily practice, without the use of more efficient technologies, such as coronary angiography by computed tomography, safe and efficient stratification of patients with acute chest pain remains a challenge to the medical team in the emergency room. Recently, several studies, including three randomized trials, showed favorable results with the use of this technology in the emergency department for patients with low to intermediate likelihood of coronary artery disease. In this review, we show data resulting from coronary angiography by computed tomography in risk stratification of patients with chest pain in the emergency room, its diagnostic value, prognosis and cost-effectiveness and a critical analysis of recently published multicenter studies. PMID:24145392

  3. [Angiography of urotuberculosis (author's transl)].

    PubMed

    Klein, U; Eisenberger, F; Heinze, H G; Lissner, J; Pfeifer, K J; Runte, R; Thym, W

    1976-06-01

    119 kidneys demonstrating changes consistent with renal tuberculosis were studied in a total of 94 patients by means of selective, transfemoral renal antiography. In the first stage of the disease, this method detected parenchymal involvement which could not be visualized by excretory urography. In stage II the arcuate arteries and occasionally the intralobular arteries, showed typical changes. Cavitation, pathognomonic for the presence of renal tuberculosis were found in 39.3% of these cases. In 40% of the cases the angiographic findingd were more extensive than the apparent findings of excretory urography. Angiography, thus, can render valuable information pertaining to the course of the disease and the necessity of operative intervention. Stage III was usually characterized by extensive changes specific for parenchymal destruction. Typical vascular lesions were readily recognized. Cavitation was found in 86.5% of these cases. Tortuosity and dilatation of the renal pelvis- and/or ureter-arteries revealed evidence of ureteral involvement (stage III2). In the presence of a non-functioning kidney angiography is mandatory to rule out renal aplasia and to differentiate between a kidney destroyed by other disease processes and the complete cavitary destruction of end-stage renal tuberculosis (stage III3). PMID:959508

  4. "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.

  5. "Geyser" leakage on fluorescein angiography.

    PubMed

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

    2013-01-01

    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. PMID:24548789

  6. 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.

  7. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    MedlinePlus

    ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... time and for your attention! Spotlight Recently posted: Video: Ultrasound-guided Breast Biopsy Video: Breast MRI Video: ...

  8. Giant coronary aneurysm caused by Kawasaki disease: consistency between catheter angiography and electrocardiogram gated dual-source computed tomography angiography.

    PubMed

    Hwang, Eun-Ha; Ju, Jung-Ki; Cho, Min-Jung; Lee, Ji-Won; Lee, Hyoung-Doo

    2015-12-01

    We present the case of a 5-year-old child with coronary complications due to Kawasaki disease; this patient unintentionally underwent both dual-source computed tomography (DSCT) coronary angiography and invasive coronary angiographic examination in 2 months. This case highlights the strong consistency of the results between DSCT coronary angiography and invasive coronary angiography. Compared to conventional invasive coronary angiography, DSCT coronary angiography offered additional advantages such as minimal invasiveness and less radiation exposure. PMID:26770226

  9. Diagnostic performance of CT angiography in neck vessel trauma: systematic review and meta-analysis.

    PubMed

    Morales-Uribe, Carlos; Ramírez, Ana; Suarez-Poveda, Tatiana; Ortiz, Margarita; Sanabria, Alvaro

    2016-10-01

    This study was conducted in order to define the diagnostic performance of CT angiography for vascular injuries compared with angiography in patients with neck trauma. CT angiography is the cornerstone of diagnosis for hemodynamically stable patients with wounds suspicious of vascular trauma in the limbs, chest, or abdomen. Available evidence for the use of CT angiography in neck vascular trauma comes from small case series and few randomized controlled trials, and high-quality information does not exist regarding its performance. A protocol using the recommendations of the Cochrane Collaboration was designed. A systematic search of diagnostic studies without limits on language or time was carried out to December 2014. Studies including patients with neck trauma with retrospective or prospective data collection that assessed CT angiography compared with other methods were selected. Methodological quality was assessed using the QUADAS-2 tool. A hierarchical model ROC curve and a bivariate random effects model were used for the pooled analysis. Sixteen studies were selected and reviewed, and nine studies with 693 patients were included in this review. The overall sensitivity was 97 % (95 % CI 0.77-1.00; I (2) = 65.7 % (41.4-90.0)), while the overall specificity was 99 % (95 % CI 0.93-1.00; I (2) = 0). The hierarchic ROC curve showed an area under the curve of 0.99. Publication bias was not identified in this study. CT angiography can be stated as the gold standard for diagnosing vascular injuries in hemodynamically stable patients with neck trauma.

  10. 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.

  11. Complications with Outpatient Angiography and Interventional Procedures

    SciTech Connect

    Young, Noel; Chi, Ka-Kit; Ajaka, Joe; McKay, Lesa; O'Neill, Diane; Wong, Kai Ping

    2002-03-15

    Purpose: To prospectively identify the complications, and rates of complication, in outpatient angiography and interventional procedures. Methods: There were 1050 consecutive patients, 646 men and 404 women, aged 17-89 years, with a total of 1239 procedures studied in a 2-year period, 1997 to 1999. Results: There were 560 cases of aorto-femoral angiography,resulting in 124 complications (22%), with pain or hematoma in 110.There were 206 cases of neck and cerebral angiography, resulting in 51 complications (25%), with pain and hematoma in 34, transient ischemic attack in 2 and cerebrovascular accident in 1. There were 197 interfentional procedures, with 177 being balloon dilatations, resulting in 68 complications (35%), with 2 having hematomas and 1 having hematoma/abscess requiring active treatment. There were 276 cases having various 'other' procedures (e.g., renal angiography),resulting in 65 complications (24%), with pain and hematoma in 61. No procedure-related death occurred. Eighteen cases (1.5%) had significant complications, with contrast allergy in eight. Conclusion: Outpatient angiography and intervention are relatively safe, with low significant complication rates.

  12. How coronary angiography is used. Clinical determinants of appropriateness.

    PubMed

    Chassin, M R; Kosecoff, J; Solomon, D H; Brook, R H

    1987-11-13

    Using ratings of appropriateness derived from an expert physician panel, we measured how appropriately physicians in 1981 performed coronary angiography in a randomly selected, community-based sample of cases in the Medicare population. We studied large geographic areas (three sites) in three states, representing regions of high and low use. The high-use site had fewer procedures classified as appropriate (72%) than either low-use site (77% and 81%, respectively). Over all sites, 17% of procedures were classified as inappropriate. Patients in the high-use site were older, had less severe angina, and were less intensively medically treated than patients in either of the low-use sites. Patients without angina who had not undergone exercise testing constituted the most common subgroup of inappropriate cases. Although overall differences in appropriateness were not large, practice differences do exist. This analysis of practice differences among study sites provides the clinical basis for understanding the small, but significant, differences in the appropriateness of use of coronary angiography. The finding of 17% inappropriate use may be cause for concern. PMID:3312657

  13. Newer cardiac imaging techniques: multidetector CT angiography.

    PubMed

    Davidoff, Ravin; Ruberg, Frederick L

    2006-01-01

    An update of new developments with multidetector computed tomography (MDCT) coronary angiography is presented. Similar to what has occurred with the introduction of other new technologies such as electron beam computed tomography (EBCT), life insurance medical directors are expected to evaluate a technology before there are sufficient data from large clinical trials. Well-performed studies of the performance of MDCT coronary angiography have only recently appeared. MDCT appears to perform well for excluding significant coronary disease, and will perhaps be useful in emergency room "rule-out" situations. Other applications may be for the diagnosis of significant coronary obstruction (> 75% stenosis), as well as for the evaluation of bypass grafts. Limitations include the requirement for radiologic contrast administration and significant radiation exposure. MDCT does not provide information on atheroma morphology. Given these limitations, MDCT coronary angiography utilization will grow, and it will prove to be a useful tool in specific situations. PMID:16845845

  14. Magnetic resonance angiography in neck masses.

    PubMed

    Colletti, P M; Terk, M R; Zee, C S

    1996-01-01

    Carotid MR angiography has primarily been used to evaluate for stenotic lesions. We performed 2D time of flight MR angiography in 25 patients with palpable neck masses. There were 23 masses confirmed histologically. Two of the masses represented abnormal carotid arteries. Carotid deviation was seen in 23 of 25 (92%) of patients. Widening of the carotid bifurcation was identified in seven patients, including four carotid body tumors, one inflammatory mass, one benign salivary gland tumor, and one schwannoma. Increased vascularity was identified in one carotid body tumor and in one metastatic papillary carcinoma of the thyroid. MR angiography may be useful to demonstrate flow within vessels and represents a familiar imaging display for surgical planning. Splaying of the carotid bifurcation is useful in demonstrating carotid space lesions.

  15. Optical Coherence Tomography Angiography in Fovea Plana.

    PubMed

    Dolz-Marco, Rosa; Phasukkijwatana, Nopasak; Sarraf, David; Freund, K Bailey

    2016-07-01

    Fovea plana is characterized by the anatomical absence of the foveal pit in eyes with normal visual function. The authors have analyzed three cases of idiopathic fovea plana with optical coherence tomography angiography (OCTA). As previously reported, the authors found the absence of a foveal avascular zone in all cases with OCTA; however, a preserved fusion of both the superficial and the deep capillary plexuses was found around the foveal center. This novel observation cannot be detected with conventional dye-based angiography, in which the deep capillary plexus is not visualized. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:670-673.].

  16. Intraarterial digital subtraction angiography of renal transplants

    SciTech Connect

    Picus, D.; Neeley, J.P.; McClennan, B.L.; Weyman, P.J.; Heiken, J.P.

    1985-07-01

    Twenty-four intraarterial digital subtraction angiography (IA-DSA) studies were performed in 23 renal transplant recipients for evaluation of possible postoperative complications. Ten patients had normal studies. Five patients had minimal (<50%) narrowing at the renal artery anastomosis and five had more severe stenoses. Three patients had vascular occlusions. IA-DSA results correlated well with findings at surgery and/or conventional angiography. The major advantage of IA-DSA is the small amount of contrast material needed to perform the study. IA-DSA is particularly well suited to the evaluation of vascular problems in renal transplant patients.

  17. Use of Coronary Computed Tomographic Angiography to Guide Management of Patients With Coronary Disease

    PubMed Central

    Williams, Michelle C.; Hunter, Amanda; Shah, Anoop S.V.; Assi, Valentina; Lewis, Stephanie; Smith, Joel; Berry, Colin; Boon, Nicholas A.; Clark, Elizabeth; Flather, Marcus; Forbes, John; McLean, Scott; Roditi, Giles; van Beek, Edwin J.R.; Timmis, Adam D.; Newby, David E.

    2016-01-01

    Background In a prospective, multicenter, randomized controlled trial, 4,146 patients were randomized to receive standard care or standard care plus coronary computed tomography angiography (CCTA). Objectives The purpose of this study was to explore the consequences of CCTA-assisted diagnosis on invasive coronary angiography, preventive treatments, and clinical outcomes. Methods In post hoc analyses, we assessed changes in invasive coronary angiography, preventive treatments, and clinical outcomes using national electronic health records. Results Despite similar overall rates (409 vs. 401; p = 0.451), invasive angiography was less likely to demonstrate normal coronary arteries (20 vs. 56; hazard ratios [HRs]: 0.39 [95% confidence interval (CI): 0.23 to 0.68]; p < 0.001) but more likely to show obstructive coronary artery disease (283 vs. 230; HR: 1.29 [95% CI: 1.08 to 1.55]; p = 0.005) in those allocated to CCTA. More preventive therapies (283 vs. 74; HR: 4.03 [95% CI: 3.12 to 5.20]; p < 0.001) were initiated after CCTA, with each drug commencing at a median of 48 to 52 days after clinic attendance. From the median time for preventive therapy initiation (50 days), fatal and nonfatal myocardial infarction was halved in patients allocated to CCTA compared with those assigned to standard care (17 vs. 34; HR: 0.50 [95% CI: 0.28 to 0.88]; p = 0.020). Cumulative 6-month costs were slightly higher with CCTA: difference $462 (95% CI: $303 to $621). Conclusions In patients with suspected angina due to coronary heart disease, CCTA leads to more appropriate use of invasive angiography and alterations in preventive therapies that were associated with a halving of fatal and non-fatal myocardial infarction. (Scottish COmputed Tomography of the HEART Trial [SCOT-HEART]; NCT01149590) PMID:27081014

  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. Renal Artery Stenting Using CO2 Gas Angiography in Combination with Iodinated Contrast Angiography.

    PubMed

    Adachi, Yuya; Endo, Akihiro; Nakashima, Ryuma; Sugamori, Takashi; Takahashi, Nobuyuki; Kinoshita, Yoshihisa; Tanabe, Kazuaki

    2016-01-01

    A 76-year-old woman was hospitalized repeatedly due to unexplained heart failure. On admission, she had hypertensive acute heart failure. Her symptoms disappeared promptly after the initial treatment; however, her systolic blood pressure remained at over 160 mmHg despite her taking three antihypertensive drugs. Closer examination revealed hemodynamically significant right renal artery stenosis and a lack of left kidney function. We performed percutaneous transluminal renal angioplasty using CO2 angiography in combination with iodinated contrast agents. The patient's renal function and blood pressure improved, however, CO2 gas-induced mild ischemic colitis occurred. We discuss the possibility of the use of combined iodinated contrast angiography and CO2 angiography to avoid contrast-induced nephropathy and the complications peculiar to CO2 angiography. PMID:27580543

  20. 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

  1. Unexpected Angiography Findings and Effects on Management.

    PubMed

    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. Digital subtraction angiography: patient preparation and care.

    PubMed

    Hunt, A H

    1987-08-01

    The use of digital subtraction angiography (DSA) is increasing. Nurses must be prepared to provide quality care to patients who have this relatively new method for radiographically studying the blood vessels. A description of DSA and its applications is provided. Patient preparation, assessment, teaching, and management are described. Complications of the procedure and their management are presented. PMID:2958568

  3. Computed tomographic angiography in tetralogy of Fallot.

    PubMed

    Kasar, Pankajkumar Ashok; Ravikumar, Radhakrishnan; Varghese, Roy; Kotecha, Monika; Vimala, Jesudian; Kumar, Raghavan Nair Suresh

    2011-10-01

    Echocardiography is often inadequate for imaging tetralogy of Fallot, prompting cineangiography. This study prospectively evaluated multidetector computed tomographic angiography for preoperative evaluation of tetralogy of Fallot in 112 consecutive patients. Forty-eight had nonconfluent or hypoplastic pulmonary arteries (mean z-score, -2; range, -11.1-0.13) permitting only palliative or no surgery; 64 had adequate pulmonary artery anatomy (mean z-score, 0.59; range, -2.53-3.4) allowing total repair. The surgical data of 50 patients who underwent total correction were compared with transthoracic echocardiography and multidetector computed tomographic angiography findings. Multidetector computed tomographic angiography tended to reveal unsuspected collaterals and coronary abnormalities besides outlining the right ventricular outflow tract and pulmonary artery branches. The branch pulmonary artery diameter z-score was the most important determinant of surgical strategy, with the worst figures being associated with no surgical options or palliative surgery, and the best figures leading to corrective surgery. The mean radiation dose was 3.45 mSv. Multidetector computed tomographic angiography is a powerful supplement to echocardiography in the preoperative evaluation of tetralogy of Fallot.

  4. 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.

  5. 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

  6. Clinical superiority of a new nonionic contrast agent (iopamidol) for cardiac angiography.

    PubMed

    Gertz, E W; Wisneski, J A; Chiu, D; Akin, J R; Hu, C

    1985-02-01

    The hemodynamic and electrophysiologic alterations induced by ionic contrast agents during cardiac angiography are well described. Recently nonionic contrast agents have become available for cardiac angiography. To evaluate the safety of these new agents, a double-blind randomized study was performed comparing a new nonionic agent (iopamidol) with a commonly used ionic contrast agent (Renografin-76). Eighty-one patients undergoing left ventriculography and coronary angiography were included; 41 received iopamidol and 40 received sodium meglumine diatrizoate (Renografin-76). After left ventriculography, there was a decrease in the arterial pressure with both contrast agents. However, the severity and the duration of hypotension were both significantly greater with Renografin-76 compared with the new nonionic agent (p less than 0.001). After selective injections of the coronary arteries, electrocardiographic analysis demonstrated that the increase in the QT interval (p less than 0.0002) and the changes in both the ST segment and T wave amplitude (p less than 0.001) were significantly greater in the Renografin-76 group compared with the iopamidol group. During coronary angiography, 8 of the 40 patients receiving Renografin-76 required temporary pacing for sinus pauses of 2.5 seconds or more, and 2 of the 40 also developed ventricular fibrillation. None of the 41 patients receiving iopamidol had these complications. This report demonstrates that the electrocardiographic changes, the severity and duration of hypotension and the incidence of serious arrhythmias are significantly greater with Renografin-76 than with iopamidol. Thus, this new nonionic agent appears to enhance the safety of cardiac angiography.

  7. 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

  8. 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.

  9. Optoacoustic angiography of peripheral vasculature

    NASA Astrophysics Data System (ADS)

    Ermilov, Sergey; Su, Richard; Zamora, Mario; Hernandez, Travis; Nadvoretsky, Vyacheslav; Oraevsky, Alexander

    2012-02-01

    We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vascular imaging of a human finger. The system employs an arc-shaped acoustic array that is rotated 360 degrees around the finger providing optoacoustic data necessary for tomographic reconstruction of the three-dimensional images of a finger. A near-infrared Q-switched laser is used to generate optoacoustic signals with increased contrast of blood vessels. The laser is coupled through two randomized fiberoptic bundles oriented in orthogonal optoacoustic mode. To demonstrate OmAS capabilities, we present a time-series of optoacoustic images of a human finger taken after the hypothermia stress test. The images show a detailed vascular anatomy of a finger down to the capillary level. A series of quick 30s scans allowed us to visualize the thermoregulatory response within the studied finger as it was manifested via vasomotor activity during the hypothermia recovery. We propose that the developed system can be used for diagnostics of various medical conditions that are manifested in change of the peripheral (finger) blood flow. Examples of the medical conditions that could be diagnosed and staged using the OmAS include the peripheral arterial disease (PAD), thrombosis, frostbite, and traumas.

  10. Coronary angiography in Lebanon: Use and overuse.

    PubMed

    Sibai, Abla-Mehio; Tohme, Rania A; Saade, Georges A

    2008-04-25

    Coronary angiography remains the gold standard for coronary artery disease diagnosis. In Lebanon, the density of cardiac catheterization centers is almost three times that of France (9.32 vs. 2.92 per 1,000,000 individuals) and recently collated national data indicate notably a high utilization rate of 53 per 10,000 individuals, placing Lebanon third after the United States and Germany. PMID:17399809

  11. Optical Coherence Tomography Angiography of Chorioretinal Diseases.

    PubMed

    Novais, Eduardo A; Roisman, Luiz; de Oliveira, Paulo Ricardo Chaves; Louzada, Ricardo N; Cole, Emily D; Lane, Mark; Filho, Marco Bonini; Romano, André; de Oliveira Dias, João Rafael; Regatieri, Caio V; Chow, David; Belfort, Rubens; Rosenfeld, Philip; Waheed, Nadia K; Ferrara, Daniela; Duker, Jay S

    2016-09-01

    Fluorescein angiography (FA) and indocyanine green angiography (ICGA) have been the gold standard for the evaluation of retinal and choroidal vasculature in the last three decades and have revolutionized the diagnosis of retinal and choroidal vascular diseases. The advantage of these imaging modalities lies in their ability to document retinal and choroidal vasculature through the dynamic assessment of contrast transit over time in the intravascular and extravascular spaces. However, disadvantages include the absence of depth resolution, blurring of details by contrast leakage, and the inability to selectively evaluate different levels of the retinal and choroidal microvasculature. In addition, these angiographic methods require intravenous dye, which may cause adverse reactions such as nausea, vomiting, and rarely, anaphylaxis. Optical coherence tomography angiography (OCTA) is a noninvasive imaging technique that, in contrast to dye-based angiography, is faster and depth-resolved, allowing in some cases for more precise evaluation of the vascular plexuses of the retina and choroid. The method has been demonstrated in the assessment of various vascular diseases such as venous occlusions, diabetic retinopathy, macular neovascularization, and others. Limitations of this imaging modality include a small registered field of view and the inability to visualize leakage and dye transit over time. It is also subject to a variety of artifacts, including those generated by blinking and eye movement during image acquisition. However, more than an alternative for FA and ICGA, OCTA is bringing new insights to our understanding of retinal and choroidal vascular structure and is changing fundamental paradigms in the clinical management of pathologic conditions. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:848-861.]. PMID:27631482

  12. 5-F catheter in cerebral angiography

    SciTech Connect

    O'Reilly, G.V.; Naheedy, M.H.; Colucci, V.M.; Hammerschlag, S.B.

    1981-11-01

    Although the 5-F catheter is reputed to cause less vascular trauma than larger catheters, subintimal injections of contrast material have occurred following intimal damage by the catheter tip. Microscopic studies of the tips of two widely used 5-F polyethylene catheters have revealed a difference in configuration resulting in one of the catheters becoming markedly damaged during angiography. The authors make recommendations for finishing and protecting the catheter tip.

  13. Optical Coherence Tomography Angiography in Retinal Diseases

    PubMed Central

    Chalam, K. V.; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases. PMID:27195091

  14. Optical Coherence Tomography Angiography in Retinal Diseases.

    PubMed

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  15. 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

  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. PMID:26654390

  17. Diagnostic angiography of the cerebrospinal vasculature.

    PubMed

    Rabinov, James D; Leslie-Mazwi, Thabele M; Hirsch, Joshua A

    2016-01-01

    Diagnostic catheter angiography remains the gold standard for evaluation of vascular lesions of the brain, head and neck, and spine. It is often combined with cross-sectional and functional imaging to provide a complete anatomic and physiologic workup of patients. Such data are combined with clinical information to help make treatment decisions. This chapter describes the specific techniques for arterial access and catheter navigation of the cerebrospinal vasculature. Discussion of patient positioning, injection rates, and basic anatomy of arterial and venous systems is included. Finally, important safety issues related to contrast allergy, renal failure, and complications are considered. PMID:27432664

  18. Lateral rectus palsy following coronary angiography and percutaneous coronary intervention

    PubMed Central

    Nicholson, Luke; Jones, Ruth; Hughes, David S

    2014-01-01

    We present a rare case of unilateral lateral rectus palsy following an elective coronary angiography and percutaneous coronary intervention in a 78-year-oldwoman. Ophthalmoplegia following coronary angiography is extremely rare and this is the first case of a unilateral lateral rectus palsy following the procedure. PMID:24536054

  19. 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%.

  20. 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.

  1. Iohexol, ioxaglate and iopamidol in coronary angiography. A double-blind comparative study of 300 patients.

    PubMed

    Soiva, M; Hekali, P; Keto, P; Karumo, J; Salonen, O; Heikkilä, J

    1991-05-01

    A randomized, double-blind study was carried out in 300 consecutive coronary angiography examinations to investigate the clinical safety of three low osmolar contrast media, iohexol 300, ioxaglate 320 and iopamidol 300, and the electrocardiographic changes that occurred with them. The ECG from electrode V5/V6 or AVF and intra-arterial pressure were monitored continuously, and recorded before and after the first contrast injections into the left and right coronary arteries. Of the variables tested, no statistically significant changes occurred in systolic arterial pressure, PR interval or ventricular extrasystole. The QT interval increased in the ioxaglate group (p = 0.001). Heart rate decreased in all groups, but slightly less in the ioxaglate group than in the iopamidol group (p = 0.02). The ST segment depression (mean 0.67m) was more marked in the ioxaglate group than in the other treatment groups (p = 0.0001) during right coronary angiography. The same characteristics, but less marked, were observed during left coronary angiography, the ioxaglate group (mean 0.251mm) differing from the iopamidol group (mean 0.050mm) (p = 0.04). No significant difference in severe adverse reactions were detected between these groups (ioxaglate 1, iopamidol 1). Ioxaglate produced mild side effects (nausea, vomitus, urticaria) in 16% of the patients, the other two contrast agents producing side effects in 1%.

  2. Angiography with a multifunctional line scanning ophthalmoscope

    PubMed Central

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

    2012-01-01

    Abstract. 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. PMID:22463040

  3. Contrast agent choice for intravenous coronary angiography

    SciTech Connect

    Zeman, H.D.; Siddons, D.P.

    1989-01-01

    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 monochromatic synchrotron radiation x-rays and an iodine containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic x-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the x-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation x-rays is visualizing a coronary artery through the left ventricle or aorta which also contains a contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth.

  4. Intraoperative fluorescence vascular angiography: during tibial bypass.

    PubMed

    Perry, Diana; Bharara, Manish; Armstrong, David G; Mills, Joseph

    2012-01-01

    Preventing amputations in persons with lower extremity complications of diabetes is a complex endeavor, particularly in those with concomitant ischemia and tissue loss. Fluorescence angiography (Novadaq SPY system) may provide a tool for objective evaluations of tissue viability in the diabetic foot, which is an important indicator of the ability of the diabetic ulcer to heal adequately. The SPY system uses a low-power laser coupled with a charge-coupled device camera and indocyanine green (ICG) to sequence perfusion at the surface of the skin. We present an illustrated example of the potential utility of ICG fluorescence angiography (ICGFA) before and after vascular intervention in a high-risk limb. ICGFA appeared to reveal demarcation between viable and nonviable tissue and real-time perfusion, specifically capillary fill. ICGFA clarified the extent of necessary debridement and provided an immediate indication of improvement in regional perfusion status following revascularization. Future studies involving ICGFA may include pre- and postdebridement and closure perfusion, comparison of tissue perfusion pre- and post-endovascular therapy, and lower extremity flap viability. Future works will also address the consistency of results with ICGFA by analyzing a larger cohort of patients being treated by our unit. PMID:22401340

  5. 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. PMID:27432657

  6. Carbon Dioxide Angiography: Scientific Principles and Practice

    PubMed Central

    Cho, Kyung Jae

    2015-01-01

    Carbon dioxide (CO2) is a colorless, odorless gas which occurs naturally in the atmosphere and human body. With the advent of digital subtraction angiography, the gas has been used as a safe and useful alternative contrast agent in both arteriography and venography. Because of its lack of renal toxicity and allergic potential, CO2 is a preferred contrast agent in patients with renal failure or contrast allergy, and particularly in patients who require large volumes of contrast medium for complex endovascular procedures. Understanding of the unique physical properties of CO2 (high solubility, low viscosity, buoyancy, and compressibility) is essential in obtaining a successful CO2 angiogram and in guiding endovascular intervention. Unlike iodinated contrast material, CO2 displaces the blood and produces a negative contrast for digital subtraction imaging. Indications for use of CO2 as a contrast agent include: aortography and runoff, detection of bleeding, renal transplant arteriography, portal vein visualization with wedged hepatic venous injection, venography, arterial and venous interventions, and endovascular aneurysm repair. CO2 should not be used in the thoracic aorta, the coronary artery, and cerebral circulation. Exploitation of CO2 properties, avoidance of air contamination and facile catheterization technique are important to the safe and effective performance of CO2 angiography and CO2-guided endovascular intervention. PMID:26509137

  7. 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.

  8. 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

  9. 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.

  10. Motion analysis and removal in intensity variation based OCT angiography.

    PubMed

    Liu, Xuan; Kirby, Mitchell; Zhao, Feng

    2014-11-01

    In this work, we investigated how bulk motion degraded the quality of optical coherence tomography (OCT) angiography that was obtained through calculating interframe signal variation, i.e., interframe signal variation based optical coherence angiography (isvOCA). We demonstrated theoretically and experimentally that the spatial average of isvOCA signal had an explicit functional dependency on bulk motion. Our result suggested that the bulk motion could lead to an increased background in angiography image. Based on our motion analysis, we proposed to reduce image artifact induced by transient bulk motion in isvOCA through adaptive thresholding. The motion artifact reduced angiography was demonstrated in a 1.3μm spectral domain OCT system. We implemented signal processing using graphic processing unit for real-time imaging and conducted in vivo microvasculature imaging on human skin. Our results clearly showed that the adaptive thresholding method was highly effective in the motion artifact removal for OCT angiography.

  11. Safety of contrast media in cerebral angiography: iopamidol vs. methylglucamine iothalamate.

    PubMed

    Bird, C R; Drayer, B P; Velaj, R; Triolo, P J; Allen, S; Bates, M; Yeates, A E; Heinz, E R; Osborne, D R

    1984-01-01

    A randomized double-blind study was performed in 27 patients to compare the clinical safety, incidence of pain and warmth, and film quality produced by iopamidol and Conray-60 in selective cerebral angiography. No complications or adverse reactions occurred in either group. Iopamidol was significantly less painful than was methylglucamine iothalamate for common carotid artery injections and caused significantly less heat in both common carotid and internal carotid artery injections. Film quality and diagnostic accuracy were excellent in both groups. These results, when viewed in conjunction with laboratory data demonstrating the decreased neurotoxicity of nonionic contrast agents, suggest that iopamidol is an important advance in the development of angiographic contrast media.

  12. 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

  13. Patient radiation dose from computed tomography angiography and digital subtraction angiography of the brain

    NASA Astrophysics Data System (ADS)

    Netwong, Y.; Krisanachinda, A.

    2016-03-01

    The 64-row multidetector computed tomography angiography (64-MDCTA) provides vascular image quality of the brain similar to digital subtraction angiography (DSA), but the effective dose of CTA is lower than DSA studied in phantom. The purpose of this study is to evaluate the effective dose from 64-MDCTA and DSA. Effective dose (according to ICRP 103) from 64-MDCTA and DSA flat panel detector for cerebral vessels examination of the brain using standard protocols as recommended by the manufacturer was calculated for 30 cases of MDCTA (15 male and 15 female).The mean patient age was 49.5 (23-89) yrs. 30 cases of DSA (14 male and 16 female), the mean patient age was 46.8 (21-81) yrs. For CTA, the mean effective dose was 3.7 (2.82- 5.19) mSv. For DSA, the mean effective dose was 5.78 (3.3-10.06) mSv. The effective dose of CTA depends on the scanning protocol and scan length. Low tube current can reduce patient dose whereas the number of exposures and number of series in 3D rotational angiography (3D RA) resulted in increasing effective dose in DSA patients.

  14. Magnetic resonance angiography: physical principles and applications.

    PubMed

    Kiruluta, Andrew J M; González, R Gilberto

    2016-01-01

    Magnetic resonance angiography (MRA) is the visualization of hemodynamic flow using imaging techniques that discriminate flowing spins in blood from those in stationary tissue. There are two classes of MRA methods based on whether the magnetic resonance imaging signal in flowing blood is derived from the amplitude of the moving spins, the time-of-flight methods, or is based on the phase accumulated by these flowing spins, as in phase contrast methods. Each method has particular advantages and limitations as an angiographic imaging technique, as evidenced in their application space. Here we discuss the physics of MRA for both classes of imaging techniques, including contrast-enhanced approaches and the recent rapid expansion of the techniques to fast acquisition and processing techniques using parallel imaging coils as well as their application in high-field MR systems such as 3T and 7T. PMID:27432663

  15. Adaptive thresholding of digital subtraction angiography images

    NASA Astrophysics Data System (ADS)

    Sang, Nong; Li, Heng; Peng, Weixue; Zhang, Tianxu

    2005-10-01

    In clinical practice, digital subtraction angiography (DSA) is a powerful technique for the visualization of blood vessels in the human body. Blood vessel segmentation is a main problem for 3D vascular reconstruction. In this paper, we propose a new adaptive thresholding method for the segmentation of DSA images. Each pixel of the DSA images is declared to be a vessel/background point with regard to a threshold and a few local characteristic limits depending on some information contained in the pixel neighborhood window. The size of the neighborhood window is set according to a priori knowledge of the diameter of vessels to make sure that each window contains the background definitely. Some experiments on cerebral DSA images are given, which show that our proposed method yields better results than global thresholding methods and some other local thresholding methods do.

  16. Digital subtraction angiography: overview of technical principles.

    PubMed

    Harrington, D P; Boxt, L M; Murray, P D

    1982-10-01

    The rapid development of equipment for digital subtraction angiography (DSA) has created a new diagnostic imaging method, the limits of which have not been scientifically determined. Yet through aggressive marketing, the technique is already beginning to permeate radiologic practice. The radiologist requires technical understanding of the instrumentation for informed judgment on clinical applications. DSA depends on the mating of high-resolution image-intensifier and television technology with computerized information manipulation and storage. In this overview, the individual components of the system are analyzed, from the generator to the image intensifier to the television system to the associated computer. By examining the role of each component, the current limitations and the areas of possible future development of DSA can be understood. This provides a basis for dealing with current technology and for evaluating the rapid technological changes that will occur over the next few years. PMID:6751053

  17. Targeted ROTational magnetic resonance angiography (TROTA).

    PubMed

    Goldfarb, James W

    2007-09-01

    An MR angiographic method is presented in which a rotating 2D slice is centered on and targets a region or vessel of interest. Collecting a series of slices rotating about the center of the targeted region yields projection data sufficient for the calculation of 3D volumetric data of the region using conventional backprojection reconstruction techniques. These volumetric data depict the internal structure of the vessel and can be processed and displayed with multiplanar reformation, maximum intensity projections, and 3D rendering algorithms. The rotational angiographic acquisition preserves the high temporal resolution of 2D-MR digital subtraction angiography with the added benefit of 3D reformatting and display. The method is explained in detail and results from phantom and human experiments are presented.

  18. Digital subtraction angiography in extremity trauma

    SciTech Connect

    Goodman, P.C.; Jeffrey, R.B. Jr.; Brant-Zawadzki, M.

    1984-10-01

    Digital subtraction angiography (DSA) may have considerable impact on the work-up of patients who have suffered trauma. The angiographic evaluation of vascular injuries can be accomplished rapidly and with minimal catheter use and manipulation, which is particularly important for those critically ill patients who have significant immobility because of multiple fractures. The authors retrospectively reviewed the digital subtraction angiograms in 50 consecutive cases of extremity trauma. The quality of the images in 44 of these permitted a confident diagnosis, the accuracy of which was confirmed by surgical or clinical follow-up. DSA reduces the time required to perform the procedure, the amount of contrast material injected, patient discomfort, and film cost. Its major disadvantage is the limited field size of the image intensifier.

  19. Indications for angiography in blunt thoracic trauma

    SciTech Connect

    Barcia, T.C.; Livoni, J.P.

    1983-04-01

    The clinical charts and radiographs of 113 patients who underwent aortography for suspected blunt injury to the aorta and brachiocephalic vessels were reviewed to identify the most useful indications for angiography. Eight previously described clinical criteria and 14 previously described radiographic criteria were evaluated in each of these patients, 27 of whom had either an aortic or brachiocephalic injury. Contrary to previous reports, our data indicate that no single clinical or radiographic sign is highly specific for vascular injury. An abnormal aortic outline and mediastinal widening remain the most sensitive criteria, although these were also present in a large number of patients without vascular injury. Displaced paraspinous lines and nasogastric tubes are also useful signs.

  20. Iris angiography in cystoid macular edema after cataract extraction.

    PubMed

    Kottow, M; Hendrickson, P

    1975-07-01

    Iris angiography was performed on eight patients (nine eyes), who had cystoid macular edema postcataract extraction. The fundus fluorescein angiographies showed typical star-shaped, multiloculated staining of the macular area. The iris angiographies demonstrated moderate to massive leakage of dye from the iris, and possibly leakage of ciliary body vessels into the anterior chamber, thus evidencing the until now suspected but undocumented fact that fluorescein leakage is not restricted to the fundus vessels. These data tend to support the idea that this type of macular edema is due to a vascular abnormality, and not to altered vitreous mechanics.

  1. Radionuclide angiography in juvenile angiofibroma of the nasopharynx.

    PubMed

    Castor, W F; Lentle, B C; Glazebrook, G A

    1975-01-01

    Radionuclide angiography was performed by intravenous injection of 99mTc-pertechnetate and recorded by serial gamma camera scintiphotographs. Its usefulness as a prebiopsy or preoperative procedure is demonstrated by two case reports of angiofibroma of the nasopharynx and it was also found to be useful for radiation therapy follow-up assessment. Radionuclide angiography offers a convenient and safe method to assess the vascularity of a mass and by this technique the surgeon may be alerted to the possibility of severe postbiopsy hemorrhage and also the occasional dramatic complications of radiological carotid angiography can be avoided.

  2. Nuclide angiography in Paget's disease of the skull: Case report.

    PubMed

    Fitzer, P M

    1975-07-01

    Early-appearing and persistent uptake on nuclear angiography in a patient with early Paget's disease of the skull is described. The diagnosis of subdural hematoma may be ruled out at the time of brain scanning. PMID:1167280

  3. 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.

  4. [The importance of angiography in primary retroperitoneal tumors (author's transl)].

    PubMed

    Bardach, G; Grabenwöger, F

    1982-08-01

    During the past ten years, 18 patients with primary retroperitoneal tumours were operated on in the Second Surgical Department of Vienna University. Angiography was performed preoperatively in seven patients. In five out of seven patients, the origin of the tumour and its histological grade could be determined angiographically. Hence, angiography is indicated if surgery is contemplated in addition to the more recent tomographic imaging techniques (ultrasound, computed tomography).

  5. Diagnosing intracranial vasculitis: The roles of MR and angiography

    SciTech Connect

    Harris, K.G.; Tran, D.D.; Sickels, W.J.; Cornell, S.H.; Yuh, W.T.C. )

    1994-02-01

    To describe our experience with MR and angiography in diagnosing intracranial vasculitis and to test the hypothesis that MR can be used to screen for patients unlikely to have vasculitis. Ninety-two patients who had angiography with [open quotes]exclude vasculitis[close quotes] as the indication or who had angiography and a clinical diagnosis of vasculitis were identified. Angiograms of all 92 patients and the MRs of the 70 patients who had both studies were reviewed. Eleven patients had intracranial vasculitis. Angiography showed characteristic changes in 8. MR performed in 9 of 11 vasculitis cases, was significantly abnormal in all 9. Among 70 patients who had both studies, 19 had MR that was completely normal or showed only incidental findings. None of these 19 was diagnosed with vasculitis. The diagnostic yield of angiography performed to exclude vasculitis was only 6%. Evaluation for intracranial vasculitis should include MR. A negative MR excludes intracranial vasculitis more definitively than does a negative angiogram and makes the likelihood of finding vasculitis with angiography negligible. 23 refs., 5 figs., 4 tabs.

  6. Optical Coherence Tomography Angiography in Choroideremia

    PubMed Central

    Jain, Nieraj; Jia, Yali; Gao, Simon S.; Zhang, Xinbo; Weleber, Richard G.; Huang, David; Pennesi, Mark E.

    2016-01-01

    Importance Novel therapies for choroideremia, an X-linked recessive chorioretinal degeneration, demand a better understanding of the primary site(s) of cellular degeneration. Optical coherence tomography angiography allows for choriocapillaris (CC) imaging. We compared the extent of structural alterations of the CC, retinal pigment epithelium, and photoreceptors with multimodal imaging. Observations In a clinical case series conducted from September 15,2014, through February 5,2015,14 eyes of 7 male patients with choroideremia (median age, 34 years [interquartile range, 15-46 years]; age range, 13-48 years), 4 eyes of 2 women with choroideremia carrier state (both in mid-50s), and 6 eyes of 6 controls (median age, 42.5 years [interquartile range, 33-55 years]; age range, 24-55 years) underwent multimodal imaging with optical coherence tomography angiography and electroretinography. The mean (SD) macular CC density was 82.9% (13.4%) in patients with choroideremia, 93.0% (3.8%) in female carriers, and 98.2% (1.3%) in controls. The mean (SD) CC density in affected eyes was higher in regions with preserved (92.6% [5.8%]) vs absent (75.9% [12.6%]) ellipsoid zone (mean difference. 16.7%; 95% CI, 12.1% to 21.3%; P < .001). Seventeen of 18 eyes of the patients and carriers had outer retinal tubulations forming pseudopod-like extensions from islands of preserved ellipsoid zone. Outer retinal tubulations were associated with absence of underlying retinal pigment epithelium and were longer (r = −0.62; 95% CI, −0.84 to −0.19; P < .001) and more numerous (r = −0.71; 95% CI, −0.91 to −0.27; P < .001) in more severely affected eyes. Conclusions and Relevance These findings suggest that regional changes in CC density correlate with photoreceptor structural alterations in choroideremia. Although closely coupled, the results suggest that retinal pigment epithelium loss is more extensive than photoreceptor loss. PMID:27149258

  7. Contrast agent choice for intravenous coronary angiography

    NASA Astrophysics Data System (ADS)

    Zeman, H. D.; Siddons, D. P.

    1990-05-01

    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 monochromatic synchrotron radiation X-rays and an iodine-containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic X-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron radiation source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the X-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation X-rays is visualizing a coronary artery through the left ventricle or aorta which also contain contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth. The X-ray energy spectrum of the X-17 superconduction wiggler beam line at the National Synchrotron Light Source at Brookhaven National Laboratory has been used for these calculations. Both perfect Si crystals and Si crystals with a small mosaic spread are considered as monochromators. Contrast agents containing Gd or Yb seem to have about the optimal calculated signal to noise ratio. Gd-DTPA is already approved for use as a contrast agent for

  8. Unusual congenital aortic anomaly with rare common celiamesenteric trunk variation: MR angiography and digital substraction angiography findings.

    PubMed

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

    2007-01-01

    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. PMID:17468907

  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. Microfocal angiography of the pulmonary vasculature

    NASA Astrophysics Data System (ADS)

    Clough, Anne V.; Haworth, Steven T.; Roerig, David T.; Linehan, John H.; Dawson, Christopher A.

    1998-07-01

    X-ray microfocal angiography provides a means of assessing regional microvascular perfusion parameters using residue detection of vascular indicators. As an application of this methodology, we studied the effects of alveolar hypoxia, a pulmonary vasoconstrictor, on the pulmonary microcirculation to determine changes in regional blood mean transit time, volume and flow between control and hypoxic conditions. Video x-ray images of a dog lung were acquired as a bolus of radiopaque contrast medium passed through the lobar vasculature. X-ray time-absorbance curves were acquired from arterial and microvascular regions-of-interest during both control and hypoxic alveolar gas conditions. A mathematical model based on indicator-dilution theory applied to image residue curves was applied to the data to determine changes in microvascular perfusion parameters. Sensitivity of the model parameters to the model assumptions was analyzed. Generally, the model parameter describing regional microvascular volume, corresponding to area under the microvascular absorbance curve, was the most robust. The results of the model analysis applied to the experimental data suggest a significant decrease in microvascular volume with hypoxia. However, additional model assumptions concerning the flow kinematics within the capillary bed may be required for assessing changes in regional microvascular flow and mean transit time from image residue data.

  11. Coherent bremsstrahlung used for digital subtraction angiography

    NASA Astrophysics Data System (ADS)

    Überall, Herbert

    2007-05-01

    Digital subtraction angiography (DSA), also known as Dichromography, using synchrotron radiation beams has been developed at Stanford University (R. Hofstadter) and was subsequently taken over at the Brookhaven Synchrotron and later at Hamburg (HASYLAB) [see, e.g., W.R. Dix, Physik in unserer Zeit. 30 (1999) 160]. The imaging of coronary arteries is carried out with an iodine-based contrast agent which need not be injected into the heart. The radiation must be monochromatized and is applied above and below the K-edge of iodine (33.16 keV), with a subsequent digital subtraction of the two images. Monochromatization of the synchrotron radiation causes a loss of intensity of 10 -3. We propose instead the use of coherent bremsstrahlung [see, e.g., A.W. Saenz and H. Uberall, Phys. Rev. B25 (1982) 448] which is inherently monochromatic, furnishing a flux of 10 12 photon/sec. This requires a 10-20 MeV electron linac which can be obtained by many larger hospitals, eliminating the scheduling problems present at synchrotrons. The large, broad incoherent bremsstrahlung background underlying the monochromatic spike would lead to inadmissible overexposure of the patient. This problem can be solved with the use of Kumakhov's capillary optics [see e.g., S.B.Dabagov, Physics-Uspekhi 46 (2003) 1053]: the low-energy spiked radiation can be deflected towards the patient, while the higher energy incoherent background continues forward, avoiding the patient who is placed several meters from the source.

  12. Multidetector computed tomographic angiography of aberrant subclavian arteries.

    PubMed

    Türkvatan, Aysel; Büyükbayraktar, Fatma Gül; Olçer, Tülay; Cumhur, Turhan

    2009-02-01

    The purpose of this study was to evaluate the utility of 16-slice multidetector computed tomographic (MDCT) angiography for identifying anatomic features of aberrant subclavian arteries. Seventeen patients with aberrant subclavian arteries were assessed by MDCT angiography. The aortic arch position, the presence of a Kommerell's diverticulum, aneurysm, vascular compression of trachea and oesophagus and associated cardiovascular abnormalities were evaluated. MDCT findings were confirmed by surgery in eight patients but in the other nine patients no further evaluation or management was warranted as the aberrant subclavian artery had no significant clinical consequence. Eleven patients had an aberrant right subclavian artery arising from the left aortic arch and six patients had an aberrant left subclavian artery arising from the right aortic arch. Kommerell's diverticulum was identified in three patients with an aberrant right subclavian artery and in five patients with an aberrant left subclavian artery. In two patients it was aneurysmal. Oesophageal compression was detected in eight patients, and tracheal compression was identified in only one paediatric patient. An aberrant subclavian artery was associated with complex congenital heart disease in one patient, intracardiac defects in two patients, aortic coarctation in two patients, patent ductus arteriosus in two patients and an aberrant vertebral artery in one patient. In conclusion, MDCT angiography is superior to digital subtraction angiography for the assessment of aberrant subclavian arteries since digital subtraction angiography has only a poor ability to visualize adjacent structures completely and is invasive in nature. MDCT angiography or magnetic resonance angiography are the current standard in the initial evaluation of thoracic vascular anomalies.

  13. Multi-Detector Computed Tomography Angiography for Coronary Artery Disease

    PubMed Central

    2005-01-01

    Executive Summary Purpose Computed tomography (CT) scanning continues to be an important modality for the diagnosis of injury and disease, most notably for indications of the head and abdomen. (1) According to a recent report published by the Canadian Institutes of Health Information, (1) there were about 10.3 scanners per million people in Canada as of January 2004. Ontario had the fewest number of CT scanners per million compared to the other provinces (8 CT scanners per million). The wait time for CT in Ontario of 5 weeks approaches the Canadian median of 6 weeks. This health technology and policy appraisal systematically reviews the published literature on multidetector CT (MDCT) angiography as a diagnostic tool for the newest indication for CT, coronary artery disease (CAD), and will apply the results of the review to current health care practices in Ontario. This review does not evaluate MDCT to detect coronary calcification without contrast medium for CAD screening purposes. The Technology Compared with conventional CT scanning, MDCT can provide smaller pieces of information and can cover a larger area faster. (2) Advancing MDCT technology (8, 16, 32, 64 slice systems) is capable of producing more images in less time. For general CT scanning, this faster capability can reduce the time that patients must stay still during the procedure, thereby reducing potential movement artefact. However, the additional clinical utility of images obtained from faster scanners compared to the images obtained from conventional CT scanners for current CT indications (i.e., non-moving body parts) is not known. There are suggestions that the new fast scanners can reduce wait times for general CT. MDCT angiography that utilizes a contrast medium, has been proposed as a minimally invasive replacement to coronary angiography to detect coronary artery disease. MDCT may take between 15 to 45 minutes; coronary angiography may take up to 1 hour. Although 16-slice and 32-slice CT

  14. Delayed kidney injury following coronary angiography

    PubMed Central

    WANG, FENG; PENG, CHENG; ZHANG, GUANGYUAN; ZHAO, QING; XUAN, CHANGYOU; WEI, MENG; WANG, NIANSONG

    2016-01-01

    It is occasionally observed that patients without contrast-induced nephropathy (CIN) develop kidney injury within 1–6 months after coronary angiography (CAG), termed delayed CIN or delayed kidney injury (DKI) following CAG. The present study aimed to investigate the associated risk factors of delayed CIN and its possible pathogenesis. Subjects with CAG or coronary stenting from January 2008 to December 2009 were studied. A retrospective survey on DKI after CAG was conducted and the risk factors were analyzed. There were 436 cases receiving CAG with complete medical records enrolled in the present cohort, in which the DKI incidence was 7.1% (31/436). Patients with DKI after CAG exhibited lower hemoglobin (121.2±17.3 vs. 133.8±18.6 g/l), estimated glomerular filtration rate (eGFR; 66.4±30.2 vs. 71.9±28.6 ml/min), higher serum creatinine (110.9±43.2 vs. 91.7±37.6 µmol/l), higher rate of heart failure (22.6 vs. 5.4%) and 300 mg aspirin therapy (29 vs. 5.7%) compared with non-DKI patients (all P<0.05). However, no differences were observed in morbidities of diabetes, hypertension, hyperlipidemia and proteinuria, or in the treatments with angiotensin converting enzyme (ACE) inhibitors/angiotensin II receptor-1 blockers (ARBs), diuretics, statins and other anti-platelets between the two groups (P>0.05). Logistic regression revealed that anemia, heart failure and 300 mg aspirin intake were risk factors of DKI (P<0.05), while the contrast level, isotonic contrast, diabetes, ACE inhibitors/ARBs, eGFR and other factors were not associated with DKI (P>0.05). Heart dysfunction and 300 mg aspirin therapy may contribute to DKI after CAG, and iodinated contrast media administration is not a risk factor. PMID:27347090

  15. 3D angiography. Clinical interest. First applications in interventional neuroradiology.

    PubMed

    Anxionnat, R; Bracard, S; Macho, J; Da Costa, E; Vaillant, R; Launay, L; Trousset, Y; Romeas, R; Picard, L

    1998-12-01

    3D angiography is a true technical revolution that allows improvement in the quality and safety of diagnostic and endovascular treatment procedures. 3D angiography images are obtained by reconstruction of a rotational angiography acquisition done on a C-arm (GE Medical Systems) spinning at 40 degrees per second. The carotid or vertebral selective injection of a total of 15 ml of non-ionic contrast media at 3 ml/sec over 5 seconds allows the selection of the "arterial phase". Four hundred sixty 3D angiographic studies were performed from December 1996 to September 1998 on 260 patients and have been analyzed in MIP (Maximum Intensity Projection) and SSD (Shaded Surface Display) views. The exploration of intracranial aneurysms is simplified and only requires, for each vascular axis, a biplane PA and Lateral run followed by a single rotational angiography run. The 3D angiography image is available on the workstation's screen (Advantage Workstation 3.1, GE Medical Systems) in less than 10 minutes after the acquisition of the rotational run. It therefore allows one to analyze, during the intervention, the aneurysm's angioarchitecture, in particular the neck, and select the best therapeutic technique. When endovascular treatment is the best indication, 3D angiography allows one to define the optimal angle of view and accurately select the microcoils dimensions. 3D angiography replaces the multiple oblique views that used to be required to analyze the complex aneurysms and therefore allows a reduction of the total contrast medium quantity, the patient X-ray dose and the length of the intervention time which is a safety factor. Also, in particular for complex cases, it brings additional elements complementing the results of standard 2D DSA and rotational angiograms. In the cervical vascular pathology, 3D angiography allows for a better assessment of the stenosis level and of dissection lesions. Our current research activities focus on the matching without stereotactic frame

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

    PubMed

    Duan, Hongzhou; Li, Liang; Zhang, Yang; Zhang, Jiayong; 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

  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. Detection, grading and classification of coronary stenoses in computed tomography angiography.

    PubMed

    Kelm, B Michael; Mittal, Sushil; Zheng, Yefeng; Tsymbal, Alexey; Bernhardt, Dominik; Vega-Higuera, Fernando; Zhou, S Kevin; Meer, Peter; Comaniciu, Dorin

    2011-01-01

    Recently conducted clinical studies prove the utility of Coronary Computed Tomography Angiography (CCTA) as a viable alternative to invasive angiography for the detection of Coronary Artery Disease (CAD). This has lead to the development of several algorithms for automatic detection and grading of coronary stenoses. However, most of these methods focus on detecting calcified plaques only. A few methods that can also detect and grade non-calcified plaques require substantial user involvement. In this paper, we propose a fast and fully automatic system that is capable of detecting, grading and classifying coronary stenoses in CCTA caused by all types of plaques. We propose a four-step approach including a learning-based centerline verification step and a lumen cross-section estimation step using random regression forests. We show state-of-the-art performance of our method in experiments conducted on a set of 229 CCTA volumes. With an average processing time of 1.8 seconds per case after centerline extraction, our method is significantly faster than competing approaches. PMID:22003680

  19. Anterior segment fluorescein angiography in inflammatory diseases of the cornea.

    PubMed

    Saari, K M

    1979-10-01

    To study the vascular changes in inflammatory diseases of the cornea 22 patients with various corneal inflammations were examined by means of anterior segment fluorescein angiography. Simple avascular central and marginal corneal ulcers stained with fluorescein in the late phase of angiography. An inflamed limbus and an early microscopic pannus adjacent to the ulcer were seeen in simple corneal ulcers. Progressive pannus with pronounced fluorescein leakage was observed in chronic corneal ulcer, disciform keratitis, Mooren's ulcer, and complicated acute keratoconus. In sclerokeratouveitis and in gutter associated with rheumatoid arthritis the corneal vessels showed less leakage. The iris vessels showed fluorescein leakage as a sign of irritative iritis during the active stage of simple and chronic corneal ulcers, in disciform keratitis, Mooren's ulcer, and in graft rejection. It is concluded that anterior segment fluorescein angiography gives valuable information of the vascular architecture, flow and leakage in inflammatory diseases of the cornea.

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

    PubMed

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

    2016-08-01

    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. 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

  2. Glucagon-Induced Vasospasm of Hepatic Artery Branches During Visceral Angiography

    SciTech Connect

    Dziedzic, T. Scott; Smith, Tony P.

    2008-07-15

    Glucagon is often used in radiology to decrease bowel motility for enhanced imaging, including visceral digital subtraction angiography. We present a case in which branch hepatic artery vasospasm followed the intravenous administration of glucagon during visceral angiography.

  3. When is rotational angiography superior to conventional single‐plane angiography for planning coronary angioplasty?

    PubMed Central

    Taylor, Jane; Boutong, Sara; Brett, Sarah; Louis, Amal; Heppenstall, James; Morton, Allison C.; Gunn, Julian P.

    2015-01-01

    Objectives To investigate the value of rotational coronary angiography (RoCA) in the context of percutaneous coronary intervention (PCI) planning. Background As a diagnostic tool, RoCA is associated with decreased patient irradiation and contrast use compared with conventional coronary angiography (CA) and provides superior appreciation of three‐dimensional anatomy. However, its value in PCI remains unknown. Methods We studied stable coronary artery disease assessment and PCI planning by interventional cardiologists. Patients underwent either RoCA or conventional CA pre‐PCI for planning. These were compared with the referral CA (all conventional) in terms of quantitative lesion assessment and operator confidence. An independent panel reanalyzed all parameters. Results Six operators performed 127 procedures (60 RoCA, 60 conventional CA, and 7 crossed‐over) and assessed 212 lesions. RoCA was associated with a reduction in the number of lesions judged to involve a bifurcation (23 vs. 30 lesions, P < 0.05) and a reduction in the assessment of vessel caliber (2.8 vs. 3.0 mm, P < 0.05). RoCA improved confidence assessing lesion length (P = 0.01), percentage stenosis (P = 0.02), tortuosity (P < 0.04), and proximity to a bifurcation (P = 0.03), particularly in left coronary artery cases. X‐ray dose, contrast agent volume, and procedure duration were not significantly different. Conclusions Compared with conventional CA, RoCA augments quantitative lesion assessment, enhances confidence in the assessment of coronary artery disease and the precise details of the proposed procedure, but does not affect X‐ray dose, contrast agent volume, or procedure duration. © 2015 Wiley Periodicals, Inc. PMID:26012725

  4. 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

  5. Optical Coherence Tomography Angiography of Optic Disc Perfusion in Glaucoma

    PubMed Central

    Jia, Yali; Wei, Eric; Wang, Xiaogang; Zhang, Xinbo; Morrison, John C.; Parikh, Mansi; Lombardi, Lori H.; Gattey, Devin M.; Armour, Rebecca L.; Edmunds, Beth; Kraus, Martin F.; Fujimoto, James G.; Huang, David

    2014-01-01

    Purpose To compare optic disc perfusion between normal and glaucoma subjects using optical coherence tomography (OCT) angiography and detect optic disc perfusion changes in glaucoma. Design Observational, cross-sectional study. Participants Twenty-four normal subjects and 11 glaucoma patients were included. Methods One eye of each subject was scanned by a high-speed 1050 nm wavelength swept-source OCT instrument. The split-spectrum amplitude-decorrelation angiography algorithm (SSADA) was used to compute three-dimensional optic disc angiography. A disc flow index was computed from four registered scans. Confocal scanning laser ophthalmoscopy (cSLO) was used to measure disc rim area, and stereo photography was used to evaluate cup/disc ratios. Wide field OCT scans over the discs were used to measure retinal nerve fiber layer (NFL) thickness. Main Outcome Measurements Variability was assessed by coefficient of variation (CV). Diagnostic accuracy was assessed by sensitivity and specificity. Comparisons between glaucoma and normal groups were analyzed by Wilcoxon rank-sum test. Correlations between disc flow index, structural assessments, and visual field (VF) parameters were assessed by linear regression. Results In normal discs, a dense microvascular network was visible on OCT angiography. This network was visibly attenuated in glaucoma subjects. The intra-visit repeatability, inter-visit reproducibility, and normal population variability of the optic disc flow index were 1.2%, 4.2%, and 5.0% CV respectively. The disc flow index was reduced by 25% in the glaucoma group (p = 0.003). Sensitivity and specificity were both 100% using an optimized cutoff. The flow index was highly correlated with VF pattern standard deviation (R2 = 0.752, p = 0.001). These correlations were significant even after accounting for age, cup/disc area ratio, NFL, and rim area. Conclusions OCT angiography, generated by the new SSADA algorithm, repeatably measures optic disc perfusion. OCT

  6. Right ventricular volume analysis by angiography in right ventricular cardiomyopathy.

    PubMed

    Indik, Julia H; Dallas, William J; Gear, Kathleen; Tandri, Harikrishna; Bluemke, David A; Moukabary, Talal; Marcus, Frank I

    2012-06-01

    Imaging of the right ventricle (RV) for the diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is commonly performed by echocardiography or magnetic resonance imaging (MRI). Angiography is an alternative modality, particularly when MRI cannot be performed. We hypothesized that RV volume and ejection fraction computed by angiography would correlate with these quantities as computed by MRI. RV volumes and ejection fraction were computed for subjects enrolled in the North American ARVC/D Registry, with both RV angiography and MRI studies. Angiography was performed in the 30° right anterior oblique (RAO) and 60° left anterior oblique (LAO) views. Angiographic volumes were computed by RAO view and two-view (RAO and LAO) formulae. 17 subjects were analyzed (11 men and 6 women), with 15 subjects classified as affected, and two as unaffected by modified Task Force criteria. The correlation coefficient of MRI to the two-view angiographic analysis was 0.72 (P = 0.003) for end-diastolic volume and 0.68 (P = 0.005) for ejection fraction. Angiographically derived volumes were larger than MRI derived volume (P = 0.009) and with the slope in a linear relationship equal to 0.8 for end diastolic volume, and 0.9 for RV ejection fraction (P < 0.001), computed by the two view formula. End-diastolic volumes and ejection fractions of the RV obtained by dual view angiography correlate with these quantities by MRI. RV end-diastolic volumes are larger by RV angiography in comparison with MRI.

  7. Detection of viable myocardium using coronary angiography and ventriculography.

    PubMed

    Conti, C Richard

    2002-08-01

    In 2002, coronary angiography is the only way to assess precisely the combination of proximal stenoses, distal target vessels, collaterals, microcirculation, and TIMI antegrade flow. At the time of coronary angiography, global LV function is best determined using biplane ventriculography in order to correlate wall motion with coronary stenoses, distal target vessels, microcirculation, collaterals, and antegrade TIMI flow. This can be done under resting conditions after nitrates or after postextrasystolic potentiation. The absolute diagnosis of viability can only be made retrospectively. Large areas of ischemic viable myocardium should improve contraction after revascularization, decrease symptoms, and prolong survival.

  8. 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.

  9. Evaluation of the lower limb vasculature before free fibula flap transfer. A prospective blinded comparison between magnetic resonance angiography and digital subtraction angiography.

    PubMed

    Klein, Steven; Van Lienden, Krijn P; Van't Veer, Marcel; Smit, Jeroen M; Werker, Paul M N

    2013-10-01

    Introduction The aim of this study was to compare magnetic resonance angiography (MRA) with digital subtraction angiography (DSA) in the preoperative assessment of crural arteries and their skin perforators prior to free fibular transfer. Patients and methods Fifteen consecutive patients, scheduled for free vascularized fibular flap transfer, were subjected to DSA as well as MRA of the crural arteries of both legs (n = 30). All DSA and MRA images were assessed randomly, blindly, and independently by two radiologists. Each of the assessors scored the degree of stenosis of various segments on a 5 point scale from 0 (occlusive) to 4 (no stenosis). The Cohen's Kappa coefficient was used to assess the agreement between DSA and MRA scores. In addition, the number of cutaneous perforators were scored and the assessors were asked if they would advise against fibula harvest and transplantation based on the images. Results A Cohen's Kappa of 0.64, indicating "substantial agreement of stenosis severity scores" was found between the two imaging techniques. The sensitivity of MRA to detect a stenosis compared with DSA was 79% (CI 95%:60-91), and a specificity of 98% (CI 95%: 97-99). In 53 out of 60 assessments, advice on suitability for transfer were equal between DSA and MRA. The median number of cutaneous perforators that perfuse the skin overlying the fibula per leg was one for DSA as well as MRA (P = 0.142).Conclusions A substantial agreement in the assessment of stenosis severity was found between DSA and MRA. The results suggest that MRA is a good alternative to DSA in the preoperative planning of free fibula flap transplantation. PMID:24038374

  10. Comparison of Clinical Interpretation with Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary Practice: The Assessing Angiography (A2) Project

    PubMed Central

    Nallamothu, Brahmajee K.; Spertus, John A.; Lansky, Alexandra J.; Cohen, David J.; Jones, Philip G.; Kureshi, Faraz; Dehmer, Gregory J.; Drozda, Joseph P.; Walsh, Mary Norine; Brush, John E.; Koenig, Gerald C.; Waites, Thad F.; Gantt, D. Scott; Kichura, George; Chazal, Richard A.; O’Brien, Peter K.; Valentine, C. Michael; Rumsfeld, John S.; Reiber, Johan H.C.; Elmore, Joann G.; Krumholz, Richard A.; Weaver, W. Douglas; Krumholz, Harlan M.

    2013-01-01

    Background Studies conducted decades ago described substantial disagreement and errors in physicians’ angiographic interpretation of coronary stenosis severity. Despite the potential implications of such findings, no large-scale efforts to measure or improve clinical interpretation were subsequently made. Methods & Results We compared clinical interpretation of stenosis severity in coronary lesions with an independent assessment using quantitative coronary angiography (QCA) in 175 randomly selected patients undergoing elective percutaneous coronary intervention (PCI) at 7 U.S. hospitals in 2011. To assess agreement, we calculated mean difference in percent diameter stenosis between clinical interpretation and QCA and a Cohen’s weighted kappa statistic. Of 216 treated lesions, median percent diameter stenosis was 80.0% (Q1 and Q3, 80.0 and 90.0%) with 213 (98.6%) assessed as ≥70%. Mean difference in percent diameter stenosis between clinical interpretation and QCA was +8.2 ± 8.4%, reflecting an average higher percent diameter stenosis by clinical interpretation (P<0.001). A weighted kappa of 0.27 (95% CI, 0.18 to 0.36) was found between the 2 measurements. Of 213 lesions considered ≥70% by clinical interpretation, 56 (26.3%) were <70% by QCA though none was <50%. Differences between the 2 measurements were largest for intermediate lesions by QCA (50 to <70%) with variation existing across sites. Conclusions Physicians tended to assess coronary lesions treated with PCI as more severe than measurements by QCA. Almost all treated lesions were ≥70% by clinical interpretation, while approximately a quarter were <70% by QCA. These findings suggest opportunities to improve clinical interpretation of coronary angiography. PMID:23470859

  11. 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.

  12. Coronary CT Angiography versus Standard Evaluation in Acute Chest Pain

    PubMed Central

    Hoffmann, Udo; Truong, Quynh A.; Schoenfeld, David A.; Chou, Eric T.; Woodard, Pamela K.; Nagurney, John T.; Pope, J. Hector; Hauser, Thomas H.; White, Charles S.; Weiner, Scott G.; Kalanjian, Shant; Mullins, Michael E.; Mikati, Issam; Peacock, W. Frank; Zakroysky, Pearl; Hayden, Douglas; Goehler, Alexander; Lee, Hang; Gazelle, G. Scott; Wiviott, Stephen D.; Fleg, Jerome L.; Udelson, James E.

    2013-01-01

    Background It is unclear whether an evaluation incorporating coronary computed tomographic angiography (CCTA) is more effective than standard evaluation in the emergency department in patients with symptoms suggestive of acute coronary syndromes. Methods In this multicenter trial, we randomly assigned patients 40 to 74 years of age with symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic changes or an initial positive troponin test to early CCTA or to standard evaluation in the emergency department on weekdays during daylight hours between April 2010 and January 2012. The primary end point was length of stay in the hospital. Secondary end points included rates of discharge from the emergency department, major adverse cardiovascular events at 28 days, and cumulative costs. Safety end points were undetected acute coronary syndromes. Results The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard evaluation, the mean length of stay in the hospital was reduced by 7.6 hours (P<0.001) and more patients were discharged directly from the emergency department (47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes and no significant differences in major adverse cardiovascular events at 28 days. After CCTA, there was more downstream testing and higher radiation exposure. The cumulative mean cost of care was similar in the CCTA group and the standard-evaluation group ($4,289 and $4,060, respectively; P=0.65). Conclusions In patients in the emergency department with symptoms suggestive of acute coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency of clinical decision making, as compared with a standard evaluation in the emergency department, but it resulted in an increase in downstream testing and radiation exposure with no decrease in the overall costs of care. (Funded by the National

  13. Doyne memorial lecture, 1981. Fluorescein angiography. Twenty years later.

    PubMed

    Norton, E W

    1981-01-01

    A new method to study and permanently record function and structure in the living eye became available with the introduction of fluorescein angiography by Novotny and Alvis (1961). Flow and permeability in the retinal and choroidal vessels could now be correlated with anatomical changes. This presentation will review some of the major advances in our knowledge resulting from this technique. PMID:6192565

  14. Nuclear angiography in a dog with congestive cardiomyopathy

    SciTech Connect

    Lippert, A.C.; Twardock, A.R.; Gelberg, H.B.

    1986-03-01

    Nuclear angiography was used as a diagnostic aid and in monitoring the clinical course of a case of congestive cardiomyopathy in a dog. Serial examinations revealed progressively deteriorating values for left ventricular ejection fraction before the dog's death. This noninvasive technique can be an alternative to echocardiography for the evaluation of cardiac performance.

  15. 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

  16. Case Report of Bullous Pemphigoid following Fundus Fluorescein Angiography.

    PubMed

    Demirci, Goktug; Demirci, Gulsen Tukenmez; Gulkilik, Gokhan

    2010-01-01

    PURPOSE: To report a first case of bullous pemphigoid (BP) following intravenous fluorescein for fundus angiography. Clinical Features: A 70-year-old male patient was admitted to the intensive care unit with BP and sepsis. He reported a history of fundus fluorescein angiography with a pre-diagnosis of senile macular degeneration 2 months prior to presentation. At that time, fluorescein extravasated at the antecubital region. Following the procedure, pruritus and erythema began at the wrists bilaterally, and quickly spread to the entire body. The patient also reported a history of allergy to human albumin solution (Plamasteril(R); Abbott) 15 years before, during bypass surgery. On dermatologic examination, erythematous patches were present on the scalp, chest and anogenital region. Vesicles and bullous lesions were present on upper and lower extremities. On day 2 of hospitalization, tense bullae appeared on the upper and lower extremities. The patient was treated with oral methylprednisolone 48 mg (Prednol(R); Mustafa Nevzat), topical clobetasol dipropionate 0.05% cream (Dermovate(R); Glaxo SmithKline), and topical 4% urea lotion (Excipial Lipo(R); Orva) for presumptive bullous pemphigoid. Skin punch biopsy provided tissue for histopathology, direct immunofluorescence examination, and salt extraction, which were all consistent with BP. After 1 month, the patient was transferred to the intensive care unit with sepsis secondary to urinary tract infection; he died 2 weeks later from sepsis and cardiac failure. CONCLUSIONS: To our knowledge, this is the first reported case of BP following fundus fluorescein angiography in a patient with known human albumin solution allergy. Consideration should be made to avoid fluorescein angiography, change administration route, or premedicate with antihistamines in patients with known human albumin solution allergy. The association between fundus fluorescein angiography and BP should be further investigated.

  17. 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.

  18. 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

    likelihood of coronary artery disease. A bivariate random-effects model will be used to calculate pooled mean negative and positive predictive values as well as sensitivity and specificity. The primary outcome of interest will be positive and negative predictive values of coronary computed tomography angiography for the presence of coronary artery disease as a function of pretest likelihood of coronary artery disease, analyzed by meta-regression. As a secondary endpoint, factors that may influence the diagnostic performance and clinical value of computed tomography, such as heart rate and body mass index of patients, number of detector rows, and administration of beta blockade and nitroglycerin, will be investigated by integrating them as further covariates into the bivariate random-effects model. Discussion This collaborative individual patient data meta-analysis should provide answers to the pivotal question of which patients benefit most from noninvasive coronary computed tomography angiography and thus help to adequately select the right patients for this test. PMID:23414575

  19. Routine Use of Three-Dimensional Contrast-Enhanced Moving-Table MR Angiography in Patients with Peripheral Arterial Occlusive Disease: Comparison with Selective Digital Subtraction Angiography

    SciTech Connect

    Deutschmann, Hannes A.; Schoellnast, Helmut; Portugaller, Horst R.; Preidler, Klaus W.; Reittner, Pia; Tillich, Manfred; Pilger, Ernst; Szolar, Dieter H. M.

    2006-10-15

    Purpose. To compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease. Methods. Thirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA. Results. Two hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, {kappa} = 0.9 {+-} 0.03) and moderate stenosis (96.5% and 94.3%, {kappa} = 0.9 {+-} 0.03). Conclusion. Compared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.

  20. Determination of Stent Stenosis: An In Vivo Experimental Comparison of Intravascular Ultrasound and Angiography with Histology

    SciTech Connect

    Schuermann, Karl; Vorwerk, Dierk; Uppenkamp, Robert; Klosterhalfen, Bernd; Buecker, Arno; Guenther, Rolf W.

    1998-05-15

    Purpose: To compare intravascular ultrasound (IVUS) and angiography with histology in determining the degree of stent stenosis in an in vivo experiment. Methods: In 16 sheep, a total of 64 stents were implanted into the external iliac arteries. Two stents were inserted on either side. Patency was followed by angiography and IVUS. Four types of stent were used: two Dacron-covered (Cragg Endopro and heparinized Cragg Endopro) and two non-covered (Cragg and Memotherm stents). Eight animals were killed after 1 month, eight others after 6 months. Histological sections were prepared from the stented vessels. Measurements of the patent and total stent diameters determined by IVUS, angiography, and histology were compared. Results: Correlation between IVUS and angiography was 0.75, between IVUS and histology 0.77, and between angiography and histology 0.85. A mean stent stenosis of 17 {+-} 11% (range 0-51%) was found on angiography, of 10 {+-} 11% (0-46%) on IVUS, and of 20 {+-} 11% (4%-49%) on histology. In comparison with histology, IVUS underestimated the degree of stenosis by 10 {+-} 8%, and angiography underestimated it by 3 {+-} 6%. Resolution of IVUS was calculated to be about 0.35 mm and that of angiography to be about 0.15 mm. Conclusion: Under experimental conditions, IVUS was not superior to angiography in determining the degree of stent stenosis in long-segment stenoses of iliac artery stents, when measurements were correlated with histology. Angiography is sufficient for following the patency of iliac artery stents.

  1. Feature space optical coherence tomography based micro-angiography

    PubMed Central

    Zhang, Anqi; Wang, Ruikang K.

    2015-01-01

    Current optical coherence tomography (OCT) based micro-angiography is prone to noise that arises from static background. This work presents a novel feature space based optical micro-angiography (OMAG) method (fsOMAG) that can effectively differentiate flow signal from static background in the feature space. fsOMAG consists of two steps. In the first step a classification map is generated that provides criterion for classification in the second step to extract functional blood flow from experimental data set. The performance of fsOMAG is examined through phantom experiments and in-vivo human retinal imaging, and compared with the existing OMAG. The results indicate its potential for clinical applications. PMID:26137391

  2. 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.

  3. Quantification of microvascular tortuosity during tumor evolution utilizing acoustic angiography

    PubMed Central

    Shelton, Sarah E.; Lee, Yueh Z.; Lee, Mike; Cherin, Emmanuel; Foster, F. Stuart; Aylward, Stephen R.; Dayton, Paul A.

    2016-01-01

    The recent design of ultra-broadband, multi-frequency ultrasound transducers has enabled high sensitivity, high-resolution contrast imaging, with very efficient suppression of tissue background using a technique called acoustic angiography. Here we perform the first application of acoustic angiography to evolving tumors in mice predisposed to develop mammary carcinoma, with the intent of visualizing and quantifying angiogenesis progression associated with tumor growth. Metrics compared include vascular density and two measures of vessel tortuosity quantified from segmentations of vessels traversing and surrounding 24 tumors and abdominal vessels from control mice. Quantitative morphological analysis of tumor vessels demonstrated significantly increased vascular tortuosity abnormalities associated with tumor growth with the distance metric elevated approximately 14% and the sum of angles metric increased 60% in tumor vessels versus controls. Future applications of this imaging approach may provide clinicians a new tool in tumor detection, differentiation, or evaluation, though with limited depth of penetration using the current configuration. PMID:25858001

  4. 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.

  5. Waiting for coronary angiography: is there a clinically ordered queue?

    PubMed

    Hemingway, H; Crook, A M; Feder, G; Dawson, J R; Timmis, A

    2000-03-18

    Among over 3000 patients undergoing coronary angiography in the absence of a formal queue-management system, we found that a-priori urgency scores were strongly associated with waiting times, prevalence of coronary-artery disease, rate of revascularisation, and mortality. These data challenge the widely held assumption that such waiting lists are not clinically ordered; however, the wide variation in waiting times within urgency categories suggests the need for further improvements in clinical queueing.

  6. 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.

  7. 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

  8. Diagnosing flow residuals in coiled cerebral aneurysms by MR angiography: meta-analysis.

    PubMed

    Menke, Jan; Schramm, Peter; Sohns, Jan Martin; Kallenberg, Kai; Staab, Wieland

    2014-04-01

    This meta-analysis summarizes the accuracy of magnetic resonance angiography (MRA) for diagnosing residuals in coiled cerebral aneurysms by using the threefold Roy classification (residuals: none, neck, or sac). Four databases were searched from 2000 to June 2013 for eligible studies that compared MRA to digital subtraction angiography (DSA) and reported 3 × 3 count data of threefold Roy classification, or a reduced scheme of 2 × 2 count data. Bivariate and trivariate Bayesian random-effects models were used for meta-analysis. Among 27 included studies (2,119 coiled aneurysms in 1,809 patients) the average prevalence of DSA-confirmed sac residuals was 18.2 % (range 0-43 %). The pooled sensitivity was 88.0 % (95 % CI 81.4-94.0) and specificity was 97.2 % (94.6-99.0 %) for assessing sac residuals by MRA. In the trivariate meta-analysis, a "sac residual" finding at MRA had a high positive likelihood ratio of 28.2 (14.0-79.0). A "neck residual" finding had a moderate negative likelihood ratio of 0.246 (0.111-0.426), and the MRA finding of "no residual" had a good negative likelihood ratio of 0.044 (0.013-0.096). Subgroup analyses identified no significant influence of covariates on diagnostic accuracy (P > 0.05). In conclusion, in coiled cerebral aneurysms MRA with application of the threefold Roy classification is well suited for detecting or excluding sac residuals that might require retreatment. PMID:23893001

  9. Novel Fluorescein Angiography-Based Computer-Aided Algorithm for Assessment of Retinal Vessel Permeability

    PubMed Central

    Chassidim, Yoash; Parmet, Yisrael; Tomkins, Oren; Knyazer, Boris; Friedman, Alon; Levy, Jaime

    2013-01-01

    Purpose To present a novel method for quantitative assessment of retinal vessel permeability using a fluorescein angiography-based computer algorithm. Methods Twenty-one subjects (13 with diabetic retinopathy, 8 healthy volunteers) underwent fluorescein angiography (FA). Image pre-processing included removal of non-retinal and noisy images and registration to achieve spatial and temporal pixel-based analysis. Permeability was assessed for each pixel by computing intensity kinetics normalized to arterial values. A linear curve was fitted and the slope value was assigned, color-coded and displayed. The initial FA studies and the computed permeability maps were interpreted in a masked and randomized manner by three experienced ophthalmologists for statistical validation of diagnosis accuracy and efficacy. Results Permeability maps were successfully generated for all subjects. For healthy volunteers permeability values showed a normal distribution with a comparable range between subjects. Based on the mean cumulative histogram for the healthy population a threshold (99.5%) for pathological permeability was determined. Clear differences were found between patients and healthy subjects in the number and spatial distribution of pixels with pathological vascular leakage. The computed maps improved the discrimination between patients and healthy subjects, achieved sensitivity and specificity of 0.974 and 0.833 respectively, and significantly improved the consensus among raters for the localization of pathological regions. Conclusion The new algorithm allows quantification of retinal vessel permeability and provides objective, more sensitive and accurate evaluation than the present subjective clinical diagnosis. Future studies with a larger patients’ cohort and different retinal pathologies are awaited to further validate this new approach and its role in diagnosis and treatment follow-up. Successful evaluation of vasculature permeability may be used for the early

  10. Comparison of low osmolality ionic (ioxaglate) versus nonionic (iopamidol) contrast media in cardiac angiography.

    PubMed

    Wisneski, J A; Gertz, E W; Dahlgren, M; Muslin, A

    1989-02-15

    A double-blind randomized study was performed in 60 patients to compare the electrocardiographic and hemodynamic changes induced during cardiac angiography by 2 contrast media with relatively low osmolality. Ioxaglate meglumine sodium, an ionic dimer contrast medium, was compared with iopamidol, a nonionic compound. Of the 30 patients who received ioxaglate, 13 (43%) experienced a mild to moderate adverse reaction to the contrast media, while only 2 of the 30 patients (7%) in the iopamidol group had similar side effects (p less than 0.005). Significant prolongations of the QT intervals occurred with the ioxaglate injections. The QT intervals increased from 402 +/- 46 to 442 +/- 59 ms (p less than 0.001) with the right coronary artery injection and similar changes were observed after the left coronary artery injection and left ventriculography. Significant ST-segment and T-wave amplitude changes also occurred in the ioxaglate group. With iopamidol injections, there were no significant changes in any of these parameters. After the left ventriculogram, there were similar decreases in the systolic arterial pressures in both groups (-14 +/- 10 mm Hg with ioxaglate and -21 +/- 9 mm Hg with iopamidol). The left ventricular end-diastolic pressures increased after the ventriculogram in both groups (5 +/- 5 vs 2 +/- 3 mm Hg with ioxaglate and iopamidol, respectively, 60 seconds after the injection). This report demonstrates that mild to moderate adverse reactions, QT-interval prolongations, ST and T-wave changes were significantly greater during coronary angiography with ioxaglate when compared with iopamidol.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Acoustic angiography: a new imaging modality for assessing microvasculature architecture.

    PubMed

    Gessner, Ryan C; Frederick, C Brandon; Foster, F Stuart; Dayton, Paul A

    2013-01-01

    The purpose of this paper is to provide the biomedical imaging community with details of a new high resolution contrast imaging approach referred to as "acoustic angiography." Through the use of dual-frequency ultrasound transducer technology, images acquired with this approach possess both high resolution and a high contrast-to-tissue ratio, which enables the visualization of microvascular architecture without significant contribution from background tissues. Additionally, volumetric vessel-tissue integration can be visualized by using b-mode overlays acquired with the same probe. We present a brief technical overview of how the images are acquired, followed by several examples of images of both healthy and diseased tissue volumes. 3D images from alternate modalities often used in preclinical imaging, contrast-enhanced micro-CT and photoacoustics, are also included to provide a perspective on how acoustic angiography has qualitatively similar capabilities to these other techniques. These preliminary images provide visually compelling evidence to suggest that acoustic angiography may serve as a powerful new tool in preclinical and future clinical imaging. PMID:23997762

  12. Body MR angiography in children: how we do it.

    PubMed

    Krishnamurthy, Rajesh; Malone, LaDonna; Lyons, Karen; Ketwaroo, Pamela; Dodd, Nicholas; Ashton, Daniel

    2016-05-01

    Vascular pathology is ubiquitous in children. Common indications for angiographic imaging in the body include congenital anomalies, portal hypertension, assessing resectability of neoplasms, renovascular hypertension, vascular malformations, vasculitis, systemic vein thrombosis, and trauma. MR angiography, with or without the use of intravenous contrast agents, is therefore a mainstay in the repertoire of MR imaging in children. Pediatric contrast-enhanced MR angiography has benefited from several innovations in recent years, including improved hardware options like high-field-strength scanners and integrated high-density coil arrays, new sequences that combine parallel imaging, innovative k-space sampling and Dixon fat suppression with time-resolved imaging, new contrast agents with longer blood-pool residence time, and advanced post-processing solutions like image fusion. This article focuses on the principles of contrast-enhanced MR angiography of the body as it pertains to the physiologies and pathologies encountered in children. It also discusses tools to adapt the MR angiographic technique to the clinical indication, as well as pitfalls of post-processing and interpretation in commonly encountered vascular imaging scenarios in the pediatric body. PMID:27229494

  13. Delayed clopidogrel transit during myocardial infarction evident on angiography.

    PubMed

    Ghobrial, Joanna; Gibson, C Michael; Pinto, Duane S

    2015-05-01

    We describe the case of a patient with non-ST segment elevation myocardial infarction (NSTEMI) where a limitation of oral clopidogrel loading prior to percutaneous coronary intervention (PCI) was directly visualized on angiography. Clopidogrel is a thienopyridine antiplatelet agent used in acute coronary syndromes. It reduces platelet aggregation via inhibition of the P2Y12 receptor. Clopidogrel is an inactive metabolite that is metabolized into the active metabolite by the cytochrome P450 isoenzymes located mostly in the liver and partly in the gastrointestinal system. As such, it requires at least 2 hours to reach maximal effect. A 63-year-old female went to an outside facility where she was diagnosed with NSTEMI and underwent angiography. She was administered 324 mg of aspirin and 600 mg of clopidogrel, and was transferred to our facility. Upon arrival, approximately 1.5 hours after the oral loading dose, the clopidogrel tablets were visualized intact in the stomach during angiography, implying a very low likelihood of adequate absorption or antiplatelet effect. This observation raises the concern that delayed gastrointestinal transit, apart from other metabolic derangements, may be a factor in achieving optimal platelet inhibition using oral agents. PMID:25929306

  14. 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.

  15. 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.

  16. 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.

  17. Ectopic Origin of Coronary Arteries Diagnozed by Coronary Angiography

    PubMed Central

    Krasniqi, Xhevdet; Gorani, Daut; Sejdiu, Basri; Citaku, Hajdin

    2016-01-01

    Introduction: Anomalous origin of coronary arteries from opposite sinus of Valsalva is rare finding. The incidence of anomalous origination of the left coronary artery from right sinus is 0.15% and the right coronary artery from the left sinus is 0.92%. The ectopic origin of left coronary artery or right coronary artery from opposite sinus depending on pathways and considering atherosclerotic changes are manifested with different clinical significance. Case report: We report two cases, the first case the coronary angiography showed the left coronary artery arising from the right coronary sinus, presenting with proximally and distally stenosed left anterior descending artery (LAD), associated with medial and distal stenosed right coronary artery (RCA). The second case the coronary angiography revealed the right coronary artery arising from the left coronary sinus, associated with tortuous medial and distal segments of left anterior descending artery (LAD), without atherosclerotic changes. The first case successfully underwent treatment procedures based on guidelines for revascularization. Conclusion: The coronary angiography of patients with coronary ischemia determines atherosclerotic disease with possibility of the presence of coronary artery anomalies that in cases with ectopic origin from opposite sinus continues to exist as a challenge during treatment in interventional cardiology. PMID:27482140

  18. Body MR angiography in children: how we do it.

    PubMed

    Krishnamurthy, Rajesh; Malone, LaDonna; Lyons, Karen; Ketwaroo, Pamela; Dodd, Nicholas; Ashton, Daniel

    2016-05-01

    Vascular pathology is ubiquitous in children. Common indications for angiographic imaging in the body include congenital anomalies, portal hypertension, assessing resectability of neoplasms, renovascular hypertension, vascular malformations, vasculitis, systemic vein thrombosis, and trauma. MR angiography, with or without the use of intravenous contrast agents, is therefore a mainstay in the repertoire of MR imaging in children. Pediatric contrast-enhanced MR angiography has benefited from several innovations in recent years, including improved hardware options like high-field-strength scanners and integrated high-density coil arrays, new sequences that combine parallel imaging, innovative k-space sampling and Dixon fat suppression with time-resolved imaging, new contrast agents with longer blood-pool residence time, and advanced post-processing solutions like image fusion. This article focuses on the principles of contrast-enhanced MR angiography of the body as it pertains to the physiologies and pathologies encountered in children. It also discusses tools to adapt the MR angiographic technique to the clinical indication, as well as pitfalls of post-processing and interpretation in commonly encountered vascular imaging scenarios in the pediatric body.

  19. 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.

  20. Impact of emergency angiography in massive lower gastrointestinal bleeding.

    PubMed Central

    Browder, W; Cerise, E J; Litwin, M S

    1986-01-01

    Fifty patients with massive lower gastrointestinal bleeding were initially managed with emergency angiography. The average age was 67.2; mean hematocrit, 23.7; and average transfusion, 7.6 units. Thirty-six patients (72%) had bleeding site located; bleeding sites were distributed throughout the colon. Etiologies of bleeding included diverticular disease (19 patients) and arteriovenous malformations (15 patients). Twenty of 22 (91%) patients receiving selective intra-arterial vasopressin stopped bleeding; however, 50% rebled on cessation of vasopressin. Thirty-five of 50 (70%) patients underwent surgery, with 57% operated on electively after vasopressin therapy. Seventeen patients had segmental colectomy, with no rebleeding. Nine of the 17 patients had diverticular disease in the remaining colon. Operative morbidity in these 35 patients was significantly improved when compared to previously reported patients undergoing emergency subtotal colectomy without angiography (8.6% vs. 37%) (p less than 0.02). Emergency angiography successfully locates the bleeding site, allowing for segmental colectomy. Vasopressin infusion transiently halts bleeding, permitting elective surgery in many instances. PMID:3094466

  1. Does cerebral angiography of cadaveric kidney donors interfere with graft function?

    PubMed

    Weibull, H; Cederholm, C; Almén, T; Bergqvist, D; Takolander, R; Husberg, B

    1987-01-01

    Cerebral angiography is used to diagnose brain death of cadaver kidney donors. Clinical and animal data suggest that angiographic contrast media may potentiate the noxious effect of renal ischemia. In order to find out if cerebral angiography of cadaveric kidney donors prior to nephrectomy interferes with function or survival of the renal grafts, two groups of cadaveric donors were compared. One group had been exposed to contrast medium from cerebral angiography in median 18 hours before nephrectomy and the other had not. There was no difference in graft survival and function between the two groups. In a previous investigation angiography was performed two hours before explantation and in that investigation there was a shorter graft survival in the angiography group than in a control group. A delay of 12 hours is suggested between cerebral angiography and explanation, to decrease the combined harmful effects of contrast media and ischemia on renal grafts.

  2. 3D multislice CT angiography in post-aortic stent grafting: a pictorial essay.

    PubMed

    Sun, Zhonghua

    2006-01-01

    Helical CT angiography has been widely used in both pre- and post-aortic stent grafting and it has been confirmed to be the preferred modality when compared to conventional angiography. The recent development of multislice CT (MSCT) has further enhanced the applications of CT angiography for aortic stent grafting. One of the advantages of MSCT angiography over conventional angiography is that the 3D reconstructions, based on the volumetric CT data, provide additional information during follow-up of aortic stent grafting. While endovascular repair has been increasingly used in clinical practice, the use of 3D MSCT imaging in endovascular repair continues to play an important role. In this pictorial essay, we aimed to discuss the diagnostic performance of 3D MSCT angiography in post aortic stent grafting, including the most commonly used surface shaded display, curvilinear reformation, the maximum intensity projection, volume rendering and virtual endoscopy. The advantages and disadvantages of each 3D reconstruction are also explored.

  3. Optical Coherence Tomography Angiography of the Peripapillary Retina in Glaucoma

    PubMed Central

    Liu, Liang; Jia, Yali; Takusagawa, Hana L.; Pechauer, Alex D.; Edmunds, Beth; Lombardi, Lorinna; Davis, Ellen; Morrison, John C.; Huang, David

    2016-01-01

    IMPORTANCE Vascular factors may have important roles in the pathophysiology of glaucoma. A practical method for the clinical evaluation of ocular perfusion is needed to improve glaucoma management. OBJECTIVE To detect peripapillary retinal perfusion in glaucomatous eyes compared with normal eyes using optical coherence tomography (OCT) angiography. DESIGN, SETTING, AND PARTICIPANTS Prospective observational study performed from July 24, 2013, to April 17, 2014. Participants were recruited and tested at Casey Eye Institute, Oregon Health & Science University. In total, 12 glaucomatous eyes and 12 age-matched normal eyes were analyzed. The optic disc region was imaged twice using a 3 × 3-mm scan by a 70-kHz, 840-nm-wavelength spectral OCT system. The split-spectrum amplitude-decorrelation angiography algorithm was used. Peripapillary flow index was calculated as the mean decorrelation value in the peripapillary region, defined as a 700-μm-wide elliptical annulus around the disc. Peripapillary vessel density was the percentage area occupied by vessels. The data statistical analysis was performed from October 30, 2013, to May 30, 2014. MAIN OUTCOMES AND MEASURES Variability was assessed by the coefficient of variation. The Mann-Whitney test was used to compare the 2 groups of eyes. Correlations between vascular and visual field variables were assessed by linear regression analysis. RESULTS In 12 normal eyes, a dense microvascular network around the disc was visible on OCT angiography. In 12 glaucomatous eyes, this network was visibly attenuated globally and focally. In normal eyes, between-visit reproducibilities of peripapillary flow index and peripapillary vessel density were 4.3% and 2.7% of the coefficient of variation, respectively, while the population variabilities of peripapillary flow index and peripapillary vessel density were 8.2% and 3.0% of the coefficient of variation, respectively. Peripapillary flow index and peripapillary vessel density in

  4. Comparison of effective doses between computed tomography cardiac angiography and conventional angiography at Pantai Hospital, Kuala Lumpur

    NASA Astrophysics Data System (ADS)

    Mohamed, Faizal; Moin, F. H. A.

    2013-05-01

    This research studies two types of cardiac angiography procedures, namely Computed Tomography Cardiac Angiography (CTCA) and Conventional Angiography (CA). The following research was executed to estimate the difference of mean effective doses that the patients received through both procedures. The mean dose-length-product (DLP) from CTCA and mean dose-area-product (DAP) from CA were utilized in calculating the effective doses. The result shows that the mean effective dose for CTCA and CA are 1.71±0.59 mSv and 53.25±14.22 mSv respectively. This proves that the mean effective dose received by patients undergoing CA is higher than patients undergoing CTCA. According to t-test, both procedures differ significantly, with a difference amounting to p<0.0001. The increases of the effective dose that the patients received through CA procedure were influenced by exposure time, the coronary anatomical condition, the operator's experience, and the operation methods.

  5. Data on copper level in the blood of patients with normal and abnormal angiography.

    PubMed

    Amiri, Leila; Movahed, Ali; Iranpour, Dariush; Ostovar, Afshin; Raeisi, Alireza; Keshtkar, Mozhgan; Hajian, Najmeh; Dobaradaran, Sina

    2016-12-01

    In this data article, we measured the levels of copper in the blood of patients undergoing coronary angiography. The samples were taken from patients with cardiovascular disease in Bushehr׳s university hospital, Iran. Patients were divided in two groups: normal angiography and abnormal angiography. After the chemical digestion of samples, the concentration levels of Cu in both groups were determined by using inductively coupled plasma optical spectrometry (ICP-OES). PMID:27622204

  6. 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

  7. Digital subtraction angiography (DSA). Work load and financial implications for a neuroradiology department.

    PubMed

    Kingsley, D P; Butler, P; Rowe, G M; Travis, R C; Wylie, I G

    1989-01-01

    A four year study has been undertaken into the effects on the workload and cost implications of the introduction of digital subtraction angiography (DSA) in a large United Kingdom teaching hospital. The increase in workload has been entirely due to the ability to perform intravenous angiography. DSA is cheaper than conventional angiography if more than 210 cases are undertaken each year. This difference is accounted for by the reduced use of X-ray film. However, intravenous angiography is more expensive because of the use of large volumes of nonionic medium. PMID:2674769

  8. 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.

  9. 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.

  10. ECG gated tomographic reconstruction for 3-D rotational coronary angiography

    PubMed Central

    Hu, Yining; Xie, Lizhe; Nunes, Jean Claude; Bellanger, Jean Jacques; Bedossa, Marc; Toumoulin, Christine

    2010-01-01

    A method is proposed for 3-D reconstruction of coronary from a limited number of projections in rotational angiography. A Bayesian maximum a posteriori (MAP) estimation is applied with a Poisson distributed projection to reconstruct the 3D coronary tree at a given instant of the cardiac cycle. Several regularizers are investigated L0-norm, L1 and L2 -norm in order to take into account the sparsity of the data. Evaluations are reported on simulated data obtained from a 3D dynamic sequence acquired on a 64-slice GE LightSpeed CT scan. A performance study is conducted to evaluate the quality of the reconstruction of the structures. PMID:21096844

  11. [Neonatal cerebral venous thrombosis: diagnosis by magnetic resonance angiography].

    PubMed

    Puig, J; Pedraza, S; Méndez, J; Trujillo, A

    2006-01-01

    Neonatal cerebral venous thrombosis (NCVT) is a rare, severe neuropathology of multiple etiology and variable clinical presentation. We describe the case of a 25-day-old infant that presented with a tonic convulsion. Ultrasound examination showed tetraventricular hemorrhage. Magnetic resonance imaging (MRI) showed the presence of acute thrombosis of the deep and superficial venous systems associated to a hemorrhagic infarct of the left thalamus. Coagulation study revealed a deficit of protein C. Thrombosis of deep cerebral veins must be ruled out as a cause of a neonatal convulsive crisis. The presence of a hemorrhagic thalamic lesion supports the diagnosis of NCVT, which must in turn be confirmed by magnetic resonance angiography (MRA).

  12. 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.

  13. Dynamic optical angiography of mouse anatomy using radial projections

    NASA Astrophysics Data System (ADS)

    Lam, Richard B.; Kruger, Robert A.; Reinecke, Daniel R.; DelRio, Stephen P.; Thornton, Michael M.; Picot, Paul A.; Morgan, Timothy G.

    2010-02-01

    We demonstrate the feasibility of optical angiography on live mice using a new photoacoustic computed tomography (PCT) scanner. The scanner uses a sparse array of discrete ultrasound detectors geometrically arranged to capture 128 simultaneous radial "projections" through a 25-mm-diameter volume of interest. Denser sets of interleaved radial projections are acquired by rotating the sparse array continuously about its vertical axis during data acquisition. The device has been designed specifically for imaging laboratory mice, which remain stationary during data collection. Angiographic data are acquired at a rate of 1280 radial projections per second following a bolus injection of 2 mg/mL of indocyanine green (ICG).

  14. Digital subtraction angiography in musculoskeletal tumors and other conditions.

    PubMed

    Kolár, J; Zídková, H; Sprindrich, J; Matĕjovský, Z

    1990-01-01

    One hundred and forty consecutive DSA examinations of various musculoskeletal diseases were analyzed with respect to the contributions and/or limits of this modern diagnostic imaging modality. Angiography remains the imaging tool of choice for many benign and malignant orthopedic conditions of bones and soft tissues, mainly when MRI is still not generally available. It remains indispensable for embolization and/or local chemotherapy. DSA has the advantage of being less invasive and it also surpasses analog arteriography in better visualization of vascular patterns hidden in hyperostosis, sclerosis, and metallic shadows. Angiographic investigations, when necessary, should therefore start with DSA. PMID:2317132

  15. 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. PMID:21746986

  16. Automated choroidal neovascularization detection algorithm for optical coherence tomography angiography

    PubMed Central

    Liu, Li; Gao, Simon S.; Bailey, Steven T.; Huang, David; Li, Dengwang; Jia, Yali

    2015-01-01

    Optical coherence tomography angiography has recently been used to visualize choroidal neovascularization (CNV) in participants with age-related macular degeneration. Identification and quantification of CNV area is important clinically for disease assessment. An automated algorithm for CNV area detection is presented in this article. It relies on denoising and a saliency detection model to overcome issues such as projection artifacts and the heterogeneity of CNV. Qualitative and quantitative evaluations were performed on scans of 7 participants. Results from the algorithm agreed well with manual delineation of CNV area. PMID:26417524

  17. Transvenous Coronary Angiography in Humans Using Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Rubenstein, Edward; Hofstadter, Robert; Zeman, Herbert D.; Thompson, Albert C.; Otis, John N.; Brown, George S.; Giacomini, John C.; Gordon, Helen J.; Kernoff, Robert S.; Harrison, Donald C.; Thomlinson, William

    1986-12-01

    The risks and costs of the present method of visualizing the coronary arteries have limited the use of coronary angiography in long-term serial studies needed to establish the natural history of coronary atherosclerosis and its response to interventions. A less invasive method, in which the contrast agent is administered intravenously, has been developed using synchrotron radiation as the illuminating source. The present report describes the initial results in human subjects. The findings indicate that transvenous coronary angiograms can be acquired in this manner. Further refinements in the x-ray imaging system are expected to result in increased x-ray fluence and improved image quality.

  18. Slovenian experience from diagnostic angiography to interventional radiology

    PubMed Central

    Pavcnik, Dusan

    2014-01-01

    Background The purpose of writing this article is to document the important events and people in the first 50 years of diagnostic angiography and interventional radiology in Slovenia. During this period not only did the name of the institutions and departments change, but also its governance. Conclusions This depicted the important roles different people played at various times in the cardiovascular divisions inside and outside of the diagnostic and interventional radiology. Historical data show that Slovenian radiology has relatively immediately introduced the new methods of interventional radiology in clinical practice. PMID:25435857

  19. 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

  20. Susac's syndrome: the value of fundus fluorescein angiography

    PubMed Central

    Khan, Imran Joseph; Allroggen, Holger; Pagliarini, Sergio

    2014-01-01

    A 19-year-old woman presented with a 4-week history of headache, ataxia, vertigo, confusion, intermittent blurred vision in the right eye and intermittent hearing loss. MRI revealed white matter lesions and ‘pepper pot’ lesions of the corpus callosum. The cerebrospinal fluid had raised protein and lymphocytes. Fundal examination revealed multiple peripheral arterial occlusions in the both eyes confirmed with fundus fluorescein angiography (FFA). A diagnosis of Susac's syndrome was made. The patient was initially treated with steroids, followed by azathioprine and intravenous immunoglobulins (IVIg). Clinical improvement was noted, associated with improvement of the retinal circulation on FFA. PMID:25281252

  1. Assessment of the kidneys: magnetic resonance angiography, perfusion and diffusion

    PubMed Central

    2011-01-01

    Renal magnetic resonance (MR) imaging has undergone major improvements in the past several years. This review focuses on the technical basics and clinical applications of MR angiography (MRA) with the goal of enabling readers to acquire high-resolution, high quality renal artery MRA. The current role of contrast agents and their safe use in patients with renal impairment is discussed. In addition, an overview of promising techniques on the horizon for renal MR is provided. The clinical value and specific applications of renal MR are critically discussed. PMID:22085467

  2. 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

  3. Quantitative optical coherence tomography angiography of vascular abnormalities in the living human eye

    PubMed Central

    Jia, Yali; Bailey, Steven T.; Hwang, Thomas S.; McClintic, Scott M.; Pennesi, Mark E.; Flaxel, Christina J.; Lauer, Andreas K.; Wilson, David J.; Hornegger, Joachim; Fujimoto, James G.; Huang, David

    2015-01-01

    Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities. PMID:25897021

  4. Combined use of intraoperative indocyanine green and dynamic angiography in rotational vertebral artery occlusion.

    PubMed

    Chaudhry, Nauman S; Ambekar, Sudheer; Elhammady, Mohamed Samy; Riley, Jonathan P; Pradilla, Gustavo; Nogueira, Raul G; Ahmad, Faiz U

    2016-08-01

    Rotational vertebral artery occlusion, also known as bow hunter's syndrome, is a well-documented surgically amenable cause of vertebrobasilar insufficiency. Traditionally, patients have been imaged using dynamic rotational angiography. The authors sought to determine whether intraoperative indocyanine green (ICG) angiography could reliably assess the adequacy of surgical decompression of the vertebral artery (VA). The authors report two patients who presented with multiple transient episodes of syncope provoked by turning their head to the right. Rotational dynamic angiography revealed a dominant VA that became occluded with head rotation to the right side. The patients underwent successful surgical decompression of the VA via an anterior cervical approach. Intraoperative ICG angiography demonstrated patency of the VA with head rotation. This was further confirmed by intraoperative dynamic catheter angiography. To our knowledge, we present the first two cases of the use of ICG combined with intraoperative dynamic rotational angiography to document the adequacy of surgical decompression of the VA in a patient with rotational vertebral artery occlusion. Intraoperative ICG angiography is a useful adjunct and may potentially supplant the need for intraoperative catheter angiography. PMID:27041076

  5. Should computed tomography angiography supersede invasive coronary angiography for the evaluation of graft patency following coronary artery bypass graft surgery?

    PubMed

    Gabriel, Joseph; Klimach, Stefan; Lang, Peter; Hildick-Smith, David

    2015-08-01

    Invasive coronary angiography (ICA) has long been the established gold standard in assessing graft patency following coronary artery bypass graft (CABG). Over the past decade or so however, improvements in computed tomography angiography (CTA) technology have allowed its emergence as a useful clinical tool in graft assessment. The recent introduction of 64-slice and now 128-slice scanners into widespread distribution, and the development of 320-detector row technology allowing volumetric imaging of the entire heart at single points in time within one cardiac cycle, has increased the potential of CTA to supersede ICA in this capacity. This study sought to examine the evidence surrounding this potential. A best evidence topic was constructed according to a structured protocol. The enquiry: In [patients who have undergone coronary artery bypass graft surgery] is [computed tomography angiography or invasive coronary angiography] superior in terms of [graft patency assessment, stenosis detection, radiation exposure and complication rate]? Four hundred and twenty-four articles were identified from the search strategy. Four additional articles were identified from references of key articles. Seventeen articles selected as best evidence were tabulated. The reliability of CTA as a tool in the detection of graft patency and stenosis has continued to improve with each successive generation of multislice technology. The latest 64- and 128-slice CTA techniques are able to detect graft patency and stenosis with very high sensitivities and specificities comparable with ICA, while remaining non-invasive procedures associated with fewer complications (ICA carries a 0.08% risk of myocardial infarction and 0.7% risk of minor complications in clinically stable patients). Present limitations of the technology include the accurate visualization of distal anastomoses and clip artefacts. In addition, the capacity of diagnostic ICA to be combined simultaneously with percutaneous coronary

  6. Can 64-row computed tomography replace angiography after coronary bypass?

    PubMed

    Doi, Hirosato; Koshima, Ryuji; Suzuki, Masato; Takahashi, Ken; Yokoyama, Hiroichi; Yoshida, Naoya

    2008-12-01

    Multi-detector (64-row) computed tomography has become an alternative to coronary angiography to diagnose graft occlusion and stenosis after coronary artery bypass. We compared the power of evaluation of multi-detector computed tomography with that of conventional coronary angiography in 60 patients who underwent coronary artery bypass with 135 grafts and 210 graft anastomoses. The diagnostic power of multi-detector computed tomography for graft occlusion was: 100% (2/2) sensitivity, 98.5% (131/133) specificity, 50% (2/4) positive predictive value, and 100% (133/133) negative predictive value; there were no significant differences in rates of occlusion among the different types of graft. The diagnostic power of multi-detector computed tomography for stenosis of the graft anastomosis was: 100% (2/2) sensitivity, 95.1% (194/204) specificity, 16.6% (2/12) positive predictive value, and 100% (194/194) negative predictive value, with no significant differences among grafts. Multi-detector computed tomography permits evaluation of bypass grafts and is much less invasive for the patients. PMID:18984751

  7. 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

  8. 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.

  9. Indocyanine green angiography in chronic central serous chorioretinopathy

    PubMed Central

    Gajdzik-Gajdecka, Urszula; Dorecka, Mariola; Nita, Ewa; Michalska, Anna; Miniewicz-Kurkowska, Joanna; Romaniuk, Wanda

    2012-01-01

    Summary Background Central serous chorioretinopathy (CSC) is a condition that originates from alterations of the choroidal circulation. The aim of this paper was to evaluate the use of indocyanine green angiography (ICGA) in patients with chronic CSC. Material/Methods The analysis included 17 patients (34 eyes) with chronic CSC in at least 1 eye. The eye examination included: distance and near visual acuity, biomicroscopy, applanation tonometry, fundus examination, colored and red-free fundus photography, evaluation of autofluorescence, optical coherence tomography, and fluorescein and indocyanine green angiography. Results In 34 eyes (100%) involved in the ICGA study the results revealed zones of transient increased choroidal vessels permeability. In 18 eyes (52.9%) choroidal changes were accompanied by a focal serous pigment epithelial detachment. In 4 eyes (11.8%) of 3 patients’ the ICGA examination confirmed the presence of occult choroidal neovascularization (CNV). In the patient with bilateral diffuse retinal pigment epitheliopathy, CNV was present in 1 eye, in the patient with unilateral chronic CSC it was also present in 1 eye, and in the third patient with bilateral chronic CSC it was detected in both eyes. Conclusions ICGA is a very useful examination that enables ophthalmologists to visualize choroidal changes due to chronic CSC, as well as to diagnose occult CNV in chronic CSC. PMID:22293877

  10. [Assessment of vertebrobasilar insufficiency using magnetic resonance angiography].

    PubMed

    Barona, R; Martínez Sanjuán, V; Campos, A; Roch, S; Brisa, A; Comeche, C

    1994-01-01

    We present the protocol for diagnosis of VBI followed by ENT and Radiology Departments of the Valencia University General Hospital, using the 2D-PC magnetic resonance angiography technique (MRA) with variable VENC (30 and 40 cm/s) with a SIGMA 1.5 T Advantage system version 5 x with the corresponding software review 5.2 (General Electric Medical Systems, Milwaukee, WI, USA). After a coronal angiographic projection is obtained in a neutral position on an axial plane of localization, the patient head is set at the maximum left and right rotation and hyperextension allowed by patient and system. In this way, a coronal angiographic sequence is obtained in order to visualize potential compressions, decreases of the flow, arterial loops, etc. MRA is a non-invasive technique that requires no contrast, does not expose the patient to ionizing radiation, and allows to change the position of the patient's head easily. Since no hospitalization is required and contraindications are minimal (e.g., implanted pacemakers...), we believe that MRA constitutes and ideal screening technique to assess the vertebro basilar system. The results obtained and the advantages provided by MRA over Doppler-ultrasound and X-ray angiography are showed. PMID:7811505

  11. Tomographic digital subtraction angiography for lung perfusion estimation in rodents

    SciTech Connect

    Badea, Cristian T.; Hedlund, Laurence W.; De Lin, Ming; Boslego Mackel, Julie S.; Samei, Ehsan; Allan Johnson, G.

    2007-05-15

    In vivo measurements of perfusion present a challenge to existing small animal imaging techniques such as magnetic resonance microscopy, micro computed tomography, micro positron emission tomography, and microSPECT, due to combined requirements for high spatial and temporal resolution. We demonstrate the use of tomographic digital subtraction angiography (TDSA) for estimation of perfusion in small animals. TDSA augments conventional digital subtraction angiography (DSA) by providing three-dimensional spatial information using tomosynthesis algorithms. TDSA is based on the novel paradigm that the same time density curves can be reproduced in a number of consecutive injections of {mu}L volumes of contrast at a series of different angles of rotation. The capabilities of TDSA are established in studies on lung perfusion in rats. Using an imaging system developed in-house, we acquired data for four-dimensional (4D) imaging with temporal resolution of 140 ms, in-plane spatial resolution of 100 {mu}m, and slice thickness on the order of millimeters. Based on a structured experimental approach, we optimized TDSA imaging providing a good trade-off between slice thickness, the number of injections, contrast to noise, and immunity to artifacts. Both DSA and TDSA images were used to create parametric maps of perfusion. TDSA imaging has potential application in a number of areas where functional perfusion measurements in 4D can provide valuable insight into animal models of disease and response to therapeutics.

  12. A storage ring based inverse Compton scattering angiography source?

    SciTech Connect

    Blum, E.B.

    1993-09-01

    Producing the 33.17 keV photons required for coronary angiography with synchrotron radiation requires a combination of a high energy storage ring with an extremely high field wiggler. Such a source may be too big and expensive to be installed in even the largest medical center. Something other than synchrotron radiation may be needed for a practical source. Inverse Compton scattering has been used in the LEGS experiment at NSLS and elsewhere to produce high energy photons. In this process, a head on collision between a low energy photon and a high energy electron transfers energy to the photon which is then emitted in approximately the direction of the incoming electron. For a given electron energy, more higher energy photons can be produced by this method than by synchrotron radiation. This suggests that inverse Compton scattering can possibly be used for a low cost angiography source. The prospects for such a source will be examined in this paper. Unfortunately, the results will show that although it is easy to obtain the required photon energy, an extremely complicated source will be needed to produce the required number of photons.

  13. 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.

  14. Digital venous angiography. A prospective evaluation in peripheral arterial trauma.

    PubMed Central

    Fabian, T C; Reiter, C B; Gold, R E; Pate, J W

    1984-01-01

    Digital venous angiography (DVA), a new radiographic technique, was prospectively compared to conventional intra-arterial angiography (CA) in a group of 153 patients with trauma and suspected peripheral arterial injury ( PAI ). Criteria for entry included: large hematoma, proximity to a major vessel, shotgun wounds, blunt injury of the extremities, and fractures or dislocations of areas with high risk of arterial injury. Patients with unequivocal clinical evidence of PAI were excluded. Study patients had both DVA and CA. Sixteen injuries were diagnosed: lacerations (9), transection (1), AV fistulae (2), thromboses (2) and minute intimal flaps (2). All patients with abnormal studies were surgically explored; there were no false-positives. There were no known false-negatives with CA. The intimal flaps were not recognized initially on DVA and their clinical significance is questioned. DVA, compared to CA in PAI , had decreased patient discomfort, cost, and morbidity. It has the potential for study of multiple areas of the body from a single I.V. catheter. DVA can probably replace CA for civilian penetrating wounds. CA may remain the standard for blunt and high velocity injuries. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:6375594

  15. 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).

  16. Random Vibrations

    NASA Technical Reports Server (NTRS)

    Messaro. Semma; Harrison, Phillip

    2010-01-01

    Ares I Zonal Random vibration environments due to acoustic impingement and combustion processes are develop for liftoff, ascent and reentry. Random Vibration test criteria for Ares I Upper Stage pyrotechnic components are developed by enveloping the applicable zonal environments where each component is located. Random vibration tests will be conducted to assure that these components will survive and function appropriately after exposure to the expected vibration environments. Methodology: Random Vibration test criteria for Ares I Upper Stage pyrotechnic components were desired that would envelope all the applicable environments where each component was located. Applicable Ares I Vehicle drawings and design information needed to be assessed to determine the location(s) for each component on the Ares I Upper Stage. Design and test criteria needed to be developed by plotting and enveloping the applicable environments using Microsoft Excel Spreadsheet Software and documenting them in a report Using Microsoft Word Processing Software. Conclusion: Random vibration liftoff, ascent, and green run design & test criteria for the Upper Stage Pyrotechnic Components were developed by using Microsoft Excel to envelope zonal environments applicable to each component. Results were transferred from Excel into a report using Microsoft Word. After the report is reviewed and edited by my mentor it will be submitted for publication as an attachment to a memorandum. Pyrotechnic component designers will extract criteria from my report for incorporation into the design and test specifications for components. Eventually the hardware will be tested to the environments I developed to assure that the components will survive and function appropriately after exposure to the expected vibration environments.

  17. Automatic pericardium segmentation and quantification of epicardial fat from computed tomography angiography.

    PubMed

    Norlén, Alexander; Alvén, Jennifer; Molnar, David; Enqvist, Olof; Norrlund, Rauni Rossi; Brandberg, John; Bergström, Göran; Kahl, Fredrik

    2016-07-01

    Recent findings indicate a strong correlation between the risk of future heart disease and the volume of adipose tissue inside of the pericardium. So far, large-scale studies have been hindered by the fact that manual delineation of the pericardium is extremely time-consuming and that existing methods for automatic delineation lack accuracy. An efficient and fully automatic approach to pericardium segmentation and epicardial fat volume (EFV) estimation is presented, based on a variant of multi-atlas segmentation for spatial initialization and a random forest classifier for accurate pericardium detection. Experimental validation on a set of 30 manually delineated computer tomography angiography volumes shows a significant improvement on state-of-the-art in terms of EFV estimation [mean absolute EFV difference: 3.8 ml (4.7%), Pearson correlation: 0.99] with run times suitable for large-scale studies (52 s). Further, the results compare favorably with interobserver variability measured on 10 volumes. PMID:27660804

  18. Intraoperative indocyanine green fluorescence angiography--an objective evaluation of anastomotic perfusion in colorectal surgery.

    PubMed

    Protyniak, Bogdan; Dinallo, Anthony M; Boyan, William P; Dressner, Roy M; Arvanitis, Michael L

    2015-06-01

    The essentials for any bowel anastomosis are: adequate perfusion, tension free, accurate tissue apposition, and minimal local spillage. Traditionally, perfusion is measured by assessing palpable pulses in the mesentery, active bleeding at cut edges, and lack of tissue discoloration. However, subjective methods lack predictive accuracy for an anastomotic leak. We used intraoperative indocyanine green (ICG) fluorescence angiography to objectively assess colon perfusion before a bowel anastomosis. Seventy-seven laparoscopic colorectal operations, between June 2013 and June 2014, were retrospectively reviewed. The perfusion to the colon and ileum was clinically assessed, and then measured using the SPY Elite Imaging System. The absolute value provided an objective number on a 0-256 gray-scale to represent differences in ICG fluorescence intensity. The lowest absolute value was used in data analysis for each anastomosis (including small bowel) to represent the theoretical least perfused/weakest anastomotic area. The lowest absolute value recorded was 20 in a patient who underwent a laparoscopic right hemicolectomy for an adenoma, with no postoperative complications. Four low anterior resection patients had additional segments of descending colon resected. There was one mortality in a patient who underwent a laparoscopic right hemicolectomy. This study illustrates an initial experience with the SPY system in colorectal surgery. The SPY provides an objective, numerical value of bowel perfusion. However, evidence is scant as to the significance of these numbers. Large-scale randomized controlled trials are required to determine specific cutoff values correlated with surgical outcomes, specifically anastomotic leak rates. PMID:26031270

  19. Murine fundus fluorescein angiography: An alternative approach using a handheld camera.

    PubMed

    Ehrenberg, Moshe; Ehrenberg, Scott; Schwob, Ouri; Benny, Ofra

    2016-07-01

    In today's modern pharmacologic approach to treating sight-threatening retinal vascular disorders, there is an increasing demand for a compact, mobile, lightweight and cost-effective fluorescein fundus camera to document the effects of antiangiogenic drugs on laser-induced choroidal neovascularization (CNV) in mice and other experimental animals. We have adapted the use of the Kowa Genesis Df Camera to perform Fundus Fluorescein Angiography (FFA) in mice. The 1 kg, 28 cm high camera has built-in barrier and exciter filters to allow digital FFA recording to a Compact Flash memory card. Furthermore, this handheld unit has a steady Indirect Lens Holder that firmly attaches to the main unit, that securely holds a 90 diopter lens in position, in order to facilitate appropriate focus and stability, for photographing the delicate central murine fundus. This easily portable fundus fluorescein camera can effectively record exceptional central retinal vascular detail in murine laser-induced CNV, while readily allowing the investigator to adjust the camera's position according to the variable head and eye movements that can randomly occur while the mouse is optimally anesthetized. This movable image recording device, with efficiencies of space, time, cost, energy and personnel, has enabled us to accurately document the alterations in the central choroidal and retinal vasculature following induction of CNV, implemented by argon-green laser photocoagulation and disruption of Bruch's Membrane, in the experimental murine model of exudative macular degeneration.

  20. Can CT angiography replace conventional bi-planar angiography in the management of severe scapulothoracic dissociation injuries?

    PubMed

    Merchant, Nishant; Scalea, Thomas; Stein, Deborah

    2012-08-01

    Severe scapulothoracic dissociation (SSTD) (Type III or IV; Zelle classification) is often life-threatening and is commonly associated with other devastating injuries. Rapid evaluation, including of the vascular system, is critical to limit the time to definitive therapy. CT angiography (CTA) has evolved as a diagnostic tool, replacing angiography (angio) as it can simultaneously evaluate bony, soft tissue, and vascular injuries. We hypothesized that CTA would be useful in evaluating patients with SSTD. We retrospectively reviewed the trauma registry between June 2002 and June 2010 to identify patients over 18 years of age who sustained SSTD. Patients that were transferred or died before diagnostic imaging were excluded. Comparisons were made between the group that underwent angio before surgery compared with CTA with regards to outcome and length of hospital and intensive care unit stay. Fourteen patients were identified with Type III or IV SSTD over the study period. In the CTA group, mean Injury Severity Score was higher, but time to definitive operative intervention was significantly shorter. There was no difference in amputation rates or mortality. Replacing arteriography with CTA in the preoperative workup of patients with SSTD reduces time to surgery. Despite a greater injury severity in the group in which CTA was used as the primary imaging modality, length of stay, amputation rates, and mortality were no different. CTA can be safely used to evaluate patients with suspected SSTD.

  1. Fractional randomness

    NASA Astrophysics Data System (ADS)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  2. Delineation of brain AVMs on MR-Angiography for the purpose of stereotactic radiosurgery

    SciTech Connect

    Buis, Dennis R. . E-mail: dr.buis@vumc.nl; Lagerwaard, Frank J.; Dirven, Clemens M.F.; Barkhof, Frederik; Knol, Dirk L.; Berg, Rene van den; Slotman, Ben J.; Vandertop, W. Peter

    2007-01-01

    Purpose: To assess the dosimetric consequences of brain arteriovenous malformation (bAVM) delineation on magnetic resonance angiography (MRA) for the purpose of stereotactic radiosurgery. Methods and Materials: Three observers contoured a bAVM in 20 patients, using digital subtraction angiography (V{sub DSA}) and three-dimensional time-of-flight MRA (V{sub MRA}). Displacement between contours was calculated. Agreement and differences between observers and imaging modalities were assessed. A standardized treatment plan with dynamic conformal arcs was generated and dosimetric coverage of all contours and the volume of normal brain tissue within the high dose region was determined. Results: The generalized reliability coefficient was 'fair' for target volume (0.79), but 'poor' for displacement (0.35). V{sub MRA} was larger than V{sub DSA} (5.0 vs. 4.0 mL, p = 0.001). No difference in displacement was found (2.8 vs. 2.5 mm, p = 0.156). Dosimetric coverage of V{sub MRA} was 62.9% (95% CI, 56.9-68.8) when V{sub DSA} was used as planning target volume, and coverage of V{sub DSA} was 83.5% (95% CI, 78.1-88.8) when V{sub MRA} was used for planning (p < 0.001). The mean volume of normal brain within the 80% isodose was larger when the bAVM was delineated on MRA (0.7 vs. 1.0 mL (p = 0.02) for targets {<=}3 mL and 3.7 vs. 7.0 mL (p = 0.01) for targets >3 mL). Conclusions: Brain arteriovenous malformations delineated on MRA are larger and more randomly displaced. However, for bAVMs {<=}3 mL, the difference in volume of normal brain tissue within the high-dose region does not seem to be clinically relevant. Therefore, MRA-images might be used as the sole imaging modality for the radiosurgical treatment of bAVMs {<=}3 mL when the bAVM is located in a noneloquent position.

  3. The HEART Pathway Randomized Trial

    PubMed Central

    Mahler, Simon A.; Riley, Robert F.; Hiestand, Brian C.; Russell, Gregory B.; Hoekstra, James W.; Lefebvre, Cedric W.; Nicks, Bret A.; Cline, David M.; Askew, Kim L.; Elliott, Stephanie B.; Herrington, David M.; Burke, Gregory L.; Miller, Chadwick D.

    2015-01-01

    Background The HEART Pathway is a decision aid designed to identify emergency department patients with acute chest pain for early discharge. No randomized trials have compared the HEART Pathway with usual care. Methods and Results Adult emergency department patients with symptoms related to acute coronary syndrome without ST-elevation on ECG (n=282) were randomized to the HEART Pathway or usual care. In the HEART Pathway arm, emergency department providers used the HEART score, a validated decision aid, and troponin measures at 0 and 3 hours to identify patients for early discharge. Usual care was based on American College of Cardiology/American Heart Association guidelines. The primary outcome, objective cardiac testing (stress testing or angiography), and secondary outcomes, index length of stay, early discharge, and major adverse cardiac events (death, myocardial infarction, or coronary revascularization), were assessed at 30 days by phone interview and record review. Participants had a mean age of 53 years, 16% had previous myocardial infarction, and 6% (95% confidence interval, 3.6%–9.5%) had major adverse cardiac events within 30 days of randomization. Compared with usual care, use of the HEART Pathway decreased objective cardiac testing at 30 days by 12.1% (68.8% versus 56.7%; P=0.048) and length of stay by 12 hours (9.9 versus 21.9 hours; P=0.013) and increased early discharges by 21.3% (39.7% versus 18.4%; P<0.001). No patients identified for early discharge had major adverse cardiac events within 30 days. Conclusions The HEART Pathway reduces objective cardiac testing during 30 days, shortens length of stay, and increases early discharges. These important efficiency gains occurred without any patients identified for early discharge suffering MACE at 30 days. PMID:25737484

  4. 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.

  5. [Indocyanine green infrared fluorescence angiography and histopathological correlation in experimental choroidal circulatory disturbance. Report 2].

    PubMed

    Matsunaga, H; Ando, A; Matsubara, T; Fukushima, I; Takahashi, K; Ohkuma, H; Uyama, M

    1997-02-01

    We performed an experimental study on choroidal circulatory disturbance to clarify basic problems about interpretation of retino-choroidal lesions in indocyanine green fluorescence angiography (ICG angiography). We severed the posterior ciliary arteries to produce choroidal circulatory disturbance. Fluorescein angiography and ICG angiography were performed at one week, and one month after occlusion. These findings were compared with histopathological findings. One week after occlusion, the area of choroidal infarct showed occlusion of choriocapillaris and proliferation of the retinal pigment epithelial (RPE) cells, this area showed hypofluorescence in the early phase ICG angiography. The hypofluorescence area increased in the late phase. One month after occlusion, the lesion showed loss of choriocapillaris at the center and proliferation of fibroblast-like cells at the edge of the lesion. The subretinal strand showed hyperfluorescence in late phase ICG angiography. Proliferated RPE cells masked ICG fluorescence in the late phase. Fibroblast-like cells showed tissue staining. When reading ICG angiography, we have to take into account that the ICG angiogram is greatly modified by condition of the RPE.

  6. 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

  7. 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.

  8. Didactics and training in cardiovascular computed tomography angiography.

    PubMed

    Bhojraj, Sanjay D; Al-Mallah, Mouaz H

    2009-01-01

    As the role of cardiovascular computed tomography angiography (CCTA) is further expanded through research, the use of this technology will expand as a result of demand both from medical professionals and the public. To ensure a standardized quality of interpretation of these scans in the face of an increased demand for physicians qualified to interpret these studies, the Society of Cardiovascular Computed Tomography, along with several other professional societies, has proposed a didactic curriculum for the study of CCTA. This review highlights the currently proposed didactic curriculum for the study of CCTA, examines current trends in training for both medical trainees and physicians in practice, and proposes future directions for the study of CCTA. PMID:19203747

  9. Didactics and training in cardiovascular computed tomography angiography.

    PubMed

    Bhojraj, Sanjay D; Al-Mallah, Mouaz H

    2009-01-01

    As the role of cardiovascular computed tomography angiography (CCTA) is further expanded through research, the use of this technology will expand as a result of demand both from medical professionals and the public. To ensure a standardized quality of interpretation of these scans in the face of an increased demand for physicians qualified to interpret these studies, the Society of Cardiovascular Computed Tomography, along with several other professional societies, has proposed a didactic curriculum for the study of CCTA. This review highlights the currently proposed didactic curriculum for the study of CCTA, examines current trends in training for both medical trainees and physicians in practice, and proposes future directions for the study of CCTA.

  10. 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.

  11. Cardiac computed tomographic angiography and the primary care physician.

    PubMed

    Mikolich, J Ronald

    2012-05-01

    Through advancements in computer processing speed and storage capacity, new cardiac imaging modalities have become clinically feasible and useful. Cardiac computed tomographic angiography, a new diagnostic imaging modality, is capable of assessing coronary artery disease and left ventricular function on a par with invasive coronary arteriography in selected patients who meet appropriate use criteria. This imaging modality is of clinical value in the assessment of patients with chest pain who have an intermediate risk of coronary atherosclerosis. The purpose of the present report is to educate primary care physicians about the basic principles of advanced cardiac imaging techniques and to convey a useful strategy for their appropriate use in the current environment of medical economics.

  12. Fundus fluorescein angiography in fundus flavimaculatus and Stargardts disease.

    PubMed

    Anmarkrud, N

    1979-04-01

    Three siblings who had fundus flavimaculatus and two patients who had Stargardts disease were studied by means of fundus fluorescein angiography. The angiograms revealed in all cases an abolished visibility of the chorioidal circulation. New flecks are usually non-fluorescent. Later on, hyperfluorescent areas are seen at identical places both in the preretinal and retinal phases, strongly indicating a window effect of the retinal layer. The missing chorioidal flush is probably due to a blocking effect of the emitting and exciting light. Some of the retinal flecks may fade away, leaving corresponding areas of hyperfluorescence that usually persist. In some cases, however, a previous fluorescent area may become non-fluorescent. The similar angiographic picture may indicate that fundus flavimaculatus and Stargardts disease are different expressions of the same disease.

  13. [Digital subtraction angiography in otorhinolaryngology--preliminary report].

    PubMed

    Liu, B; Wang, J; Bi, S

    1994-01-01

    The paper presents the preliminary experience with digital subtraction angiography (DSA) in otorhinolaryngology. This series included racemose hemangioma of the auricle in 3 cases, juvenile angiofibroma of nasopharynx in 4 cases, angioma in the retropharyngeal space in 1 case, tympanic body tumor in 1 case, traumatic epistaxis in 1 case, traumatic pseudoaneurysm in 1 case. The site, supply arteries, drainage veins of vascular tumors were shown with DSA. The intraoperative bleeding was reduced significantly by preoperative embolization of supply arteries to vascular tumors. The broken arteries of the traumatic epistaxis and the traumatic pseudoaneurysm were not only discovered but embolized. The indications and complications of DSA and measures for preventing and reducing complications were discussed.

  14. 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.

  15. [Echocardiographic gating in non-cardiac digital angiography].

    PubMed

    Gattoni, F; Baldini, U; Cairo, F; Nessi, R; Pozzato, C; Uslenghi, C

    1987-03-01

    This paper reports the results of the ECG-gating in non-cardiac digital subtraction angiography (DSA). One hundred and fifteen patients underwent DSA (126 examinations); ECG-gating was applied in 66/126 examinations: images recorded at 70% of R wave were subtracted. Artifacts produced by vascular movements were evaluated in all patients: only 40 examinations, carried out without ECG-gating, showed vascular artifacts. The major advantage of the ECG-gated DSA is the more efficient subtraction because of the better images superimposition: therefore, ECG-gating can be clinically helpful. On the contrary, it could be a problem in arrhythmic or bradycardic patients. ECG-gating is helpful in DSA imaging of the thoracic and abdominal aorta and of the cervical and renal arteries. In the examinations of peripheral vessels of the limbs it is not so efficient as in the trunk or in the neck.

  16. Imaging of the aortic valve with MRI and CT angiography.

    PubMed

    Harvey, J J; Hoey, E T D; Ganeshan, A

    2013-12-01

    The aortic valve may be affected by a wide range of congenital and acquired diseases. Echocardiography is the main non-invasive imaging technique for assessing patho-anatomical alterations of the aortic valve and adjacent structures and in many cases is sufficient to establish a diagnosis and/or guide treatment decisions. Recent technological advances in magnetic resonance imaging (MRI) and multidetector computed tomography (MDCT) have enabled these techniques to play a complimentary role in certain clinical scenarios and as such can be useful problem-solving tools. Radiologists should be familiar with the indications, advantages, and limitations of MRI and MDCT in order to advise and direct an appropriate imaging strategy depending upon the clinical scenario. This article reviews the role of MRI and MDCT angiography for assessment of the aortic valve including relevant anatomy, scan acquisition protocols, and post-processing methods. An approach to interpretation and the key imaging features of commonly encountered aortic valvular diseases are discussed.

  17. Fluorine-19 Magnetic Resonance Angiography of the Mouse

    PubMed Central

    van Heeswijk, Ruud B.; Pilloud, Yves; Flögel, Ulrich; Schwitter, Jürg; Stuber, Matthias

    2012-01-01

    Purpose To implement and characterize a fluorine-19 (19F) magnetic resonance imaging (MRI) technique and to test the hypothesis that the 19F MRI signal in steady state after intravenous injection of a perfluoro-15-crown-5 ether (PCE) emulsion may be exploited for angiography in a pre-clinical in vivo animal study. Materials and Methods In vitro at 9.4T, the detection limit of the PCE emulsion at a scan time of 10 min/slice was determined, after which the T1 and T2 of PCE in venous blood were measured. Permission from the local animal use committee was obtained for all animal experiments. 12 µl/g of PCE emulsion was intravenously injected in 11 mice. Gradient echo 1H and 19F images were obtained at identical anatomical levels. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were determined for 33 vessels in both the 19F and 1H images, which was followed by vessel tracking to determine the vessel conspicuity for both modalities. Results In vitro, the detection limit was ∼400 µM, while the 19F T1 and T2 were 1350±40 and 25±2 ms. The 19F MR angiograms selectively visualized the vasculature (and the liver parenchyma over time) while precisely coregistering with the 1H images. Due to the lower SNR of 19F compared to 1H (17±8 vs. 83±49, p<0.001), the 19F CNR was also lower at 15±8 vs. 52±35 (p<0.001). Vessel tracking demonstrated a significantly higher vessel sharpness in the 19F images (66±11 vs. 56±12, p = 0.002). Conclusion 19F magnetic resonance angiography of intravenously administered perfluorocarbon emulsions is feasible for a selective and exclusive visualization of the vasculature in vivo. PMID:22848749

  18. 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.

  19. 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.

  20. Subsecond magnetic resonance angiography and the evaluation of abnormal arteriovasuclar communications

    NASA Astrophysics Data System (ADS)

    Zachariah, Anish B.; Pereles, F. S.; Kaliney, Ryan; Carr, James C.; Collins, Jeremy D.; Wood, Cecil; Finn, John P.

    2003-05-01

    Magnetic resonance (MR) angiography is becoming widely accepted in the diagnosis of vascular diseases. When used for evaluation of arterial stenoses, aneurysm, thrombosis, or occlusion, MR angiography is a robust and accurate technique. Traditional techniques for contrast-enhanced magnetic resonance angiography (MRA) offer the benefit of high spatial resolution in characterizing vascular malformations, but have lacked the temporal resolution to describe dynamic flow events. The purpose of this project is to demonstrate the potential role of a novel technique, sub-second MRA, in the evaluation of abdominal arteriovenous malformation.

  1. EKG-gated digital subtraction angiography in the detection of pulmonary emboli. [Dogs

    SciTech Connect

    Hirji, M.; Gamsu, G.; Webb, W.R.; Brito, A.C.; Kuriyama, K.; Stern, R.G.; Cox, L.

    1984-07-01

    Detection of pulmonary emboli was investigated using electrocardiographically gated (EKG-gated) intravenous digital subtraction angiography (DSA) in 6 anesthetized and paralyzed dogs. Six autologous blood clots were introducted into the internal jugular vein of each dog and both conventional pulmonary angiography and EKG- gated DSA performed in frontal and oblique projections. The authors conclude that DSA can demonstrate individual emboli with good sensitivity and excellent precision. If several emboli are present, KEG-gated DSA should prove highly accurate; however, care must be taken because overinterpretation is more likely with DSA than with conventional pulmonary angiography.

  2. 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.

  3. Patient Selection for Diagnostic Coronary Angiography and Hospital-Level PCI Appropriateness: Insights from the NCDR®

    PubMed Central

    Bradley, Steven M.; Spertus, John A.; Kennedy, Kevin F.; Nallamothu, Brahmajee K.; Chan, Paul S.; Patel, Manesh R.; Bryson, Chris L.; Malenka, David J.; Rumsfeld, John S.

    2014-01-01

    Importance Diagnostic coronary angiography in asymptomatic patients may lead to inappropriate percutaneous coronary intervention (PCI) due to a diagnostic to therapeutic cascade. Understanding the relationship between patient selection for coronary angiography and PCI appropriateness may inform strategies to minimize inappropriate procedures. Objective To determine if hospitals that frequently perform coronary angiography in asymptomatic patients, a clinical scenario wherein the benefit of angiography is less clear, are more likely to perform inappropriate PCI. Design, Setting and Participants Multicenter observational study of 544 hospitals participating in the CathPCI Registry® between July 2009 and September 2013. Measures Hospital proportion of asymptomatic patients at diagnostic coronary angiography and a hospital's rate of inappropriate PCI, as defined by 2012 Appropriate Use Criteria for coronary revascularization. Results Of 1,225,562 patients who underwent elective coronary angiography, 308,083 (25.1%) were asymptomatic. The hospital proportion of angiograms in asymptomatic patients ranged from 1.0% to 73.6% (median 24.7%, interquartile range 15.9% to 35.9%). By hospital quartiles of asymptomatic patients at angiography, hospitals with higher rates of asymptomatic patients at angiography had higher median rates of inappropriate PCI (14.8% vs. 20.2% vs. 24.0 vs. 29.4% from lowest to highest quartile, P<.001 for trend). This was attributable to more frequent use of PCI in asymptomatic patients at hospitals with higher rates of angiography in asymptomatic patients (inappropriate and asymptomatic PCI; 5.4% vs. 9.9% vs. 14.7% vs. 21.6% from lowest to highest quartile, P<.001 for trend). Hospitals with higher rates of asymptomatic patients at angiography also had lower rates of appropriate PCI (38.6% vs. 33.0% vs. 32.3% vs. 32.9%% from lowest to highest quartile, P<.001 for trend). Conclusions and Relevance In a national sample of hospitals, performing coronary

  4. 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.

  5. Spiral Computed Tomographic Angiography of the Renal Arteries: A Prospective Comparison with Intravenous and Intraarterial Digital Subtraction Angiography

    SciTech Connect

    Farres, Maria Teresa; Lammer, Johannes; Schima, Wolfgang; Wagner, Brunhilde; Wildling, Reinhard; Winkelbauer, Friedrich; Thurnher, Siegfried

    1996-03-15

    Purpose: To assess the accuracy of computed tomographic angiography (CTA) in the evaluation of the renal arteries in comparison with intravenous (IVDSA) and intraarterial digital subtraction angiography (IADSA). Methods: In 18 patients, 35 CTAs and DSAs (27 IADSA, 8 IVDSA) of the renal arteries were performed. CTA was done with 2-3 mm collimation, 2-4 mm/sec table speed, after intravenous injection of 80 ml of contrast medium at 4 ml/sec with a scanning delay time of 14-21 sec. No previous circulation time curve was performed. CTA data were reconstructed with maximum intensity projection (MIP) and shaded surface display (SSD). The presence of stenosis was assessed on a three-point rating scale (grade 1-3). The quality of the examinations; visualization of the ostium, the main artery, and its branches; vessel sharpness, linearity, and intraluminal contrast filling were evaluated. We compared CTA with DSA. Results: CTA had 96% sensitivity, 77% specificity, and 89% accuracy in the detection of stenoses > 50%. Due to technical errors two stenoses were erroneously diagnosed as positive but there were no false negative diagnoses. The quality of CTA was good in 56% and moderate in 34% of cases. Visualization of the ostium and main artery was graded as 1.74 (out of 2) points and of the renal branches as 1.02 (out of 2) points. The quality of CTA images was worse than that of IADSA in 52%, equal in 41%, and better in 7% of cases. CTA was equal to IVDSA in 25% and better in 75% of the cases. Conclusion: CTA is an accurate noninvasive method for the evaluation of renal arteries. Examination quality is essential for the diagnosis. CTA is limited in its ability to visualize the branches of the renal artery and accessory arteries. CTA seems to be superior to IVDSA.

  6. Blood Pool Contrast-enhanced Magnetic Resonance Angiography with Correlation to Digital Subtraction Angiography: A Pictorial Review.

    PubMed

    Knuttinen, Martha-Grace; Karow, Jillian; Mar, Winnie; Golden, Margaret; Xie, Karen L

    2014-01-01

    Magnetic resonance angiography (MRA) provides noninvasive visualization of the vascular supply of soft tissue masses and vascular pathology, without harmful radiation. This is important for planning an endovascular intervention, and helps to evaluate the efficiency and effectiveness of the treatment. MRA with conventional extracellular contrast agents relies on accurate contrast bolus timing, limiting the imaging window to first-pass arterial phase. The recently introduced blood pool contrast agent (BPCA), gadofosveset trisodium, reversibly binds to human serum albumin, resulting in increased T1 relaxivity and prolonged intravascular retention time, permitting both first-pass and steady-state phase high-resolution imaging. In our practice, high-quality MRA serves as a detailed "roadmap" for the needed endovascular intervention. Cases of aortoiliac occlusive disease, inferior vena cava thrombus, pelvic congestion syndrome, and lower extremity arteriovenous malformation are discussed in this article. MRA was acquired at 1.5 T with an 8-channel phased array coil after intravenous administration of gadofosveset (0.03 mmol/kg body weight), at the first-pass phase. In the steady-state, serial T1-weighted 3D spoiled gradient echo images were obtained with high resolution. All patients underwent digital subtraction angiography (DSA) and endovascular treatment. MRA and DSA findings of vascular anatomy and pathology are discussed and correlated. BPCA-enhanced MRA provides high-quality first-pass and steady-state vascular imaging. This could increase the diagnostic accuracy and create a detailed map for pre-intervention planning. Understanding the pharmacokinetics of BPCA and being familiar with the indications and technique of MRA are important for diagnosis and endovascular intervention. PMID:25558430

  7. Is random access memory random?

    NASA Technical Reports Server (NTRS)

    Denning, P. J.

    1986-01-01

    Most software is contructed on the assumption that the programs and data are stored in random access memory (RAM). Physical limitations on the relative speeds of processor and memory elements lead to a variety of memory organizations that match processor addressing rate with memory service rate. These include interleaved and cached memory. A very high fraction of a processor's address requests can be satified from the cache without reference to the main memory. The cache requests information from main memory in blocks that can be transferred at the full memory speed. Programmers who organize algorithms for locality can realize the highest performance from these computers.

  8. Relative safety of intravenous digital subtraction angiography over other methods of carotid angiography and impact on clinical management of cerebrovascular disease.

    PubMed

    Stevens, J M; Barter, S; Kerslake, R; Schneidau, A; Barber, C; Thomas, D J

    1989-09-01

    Data from a multicentre survey based on three London teaching hospitals on the relative safety and clinical utility of intravenous carotid digital subtraction angiography (DSA) over intra-arterial DSA and conventional carotid angiography are presented. The incidence of stroke during intra-arterial DSA was 0.7% (n = 538) and during conventional angiography was 0.8% (n = 780). The incidence of stroke during intravenous DSA was zero (n = 3710). When it constituted the initial investigation, intravenous DSA achieved a 93.8% replacement value over intra-arterial studies as a whole (n = 474) and 89% replacement value for patients having carotid endarterectomy (n = 99). It was also noted that the installation of DSA equipment at one unit coincided with a sixfold increase in the number of carotid angiographic examinations and an almost threefold increase in carotid endarterectomies. PMID:2790421

  9. Time-Resolved 4-Dimensional Computed-Tomography Angiography Can Correctly Identify Carotid Pseudo-Occlusion.

    PubMed

    Ng, Felix C; Datta, Mineesh; Choi, Philip M C

    2016-04-01

    Correct identification of symptomatic high-grade internal carotid artery stenosis from low-grade or total chronic occlusion is critical for patient selection for urgent carotid endarterectomy. Carotid pseudo-occlusion is a flow-related artifact on noninvasive imaging that can lead to an incorrect diagnosis of total internal carotid artery occlusion, thereby denying an eligible patient for appropriate surgical treatment. We present an 82-year-old man with a symptomatic critical internal carotid artery, which was detected on time-resolved 4-dimensional computed-tomography angiography, whereas single-phase computed-tomography angiography, magnetic resonance angiography, and Doppler ultrasonography suggested apparent occlusion. To our understanding, the use of 4-dimensional computed-tomography angiography to identify carotid pseudo-occlusion has not been previously reported.

  10. Finding the Gatekeeper to the Cardiac Catheterization Laboratory: Coronary CT Angiography or Stress Testing?

    PubMed

    Marwick, Thomas H; Cho, Iksung; Ó Hartaigh, Bríain; Min, James K

    2015-06-30

    Functional capacity is a robust predictor of clinical outcomes, and stress testing is used in current practice paradigms to guide referral to invasive coronary angiography. However, invasive coronary angiography is driven by ongoing symptoms, as well as risk of adverse outcomes. The limitations of current functional testing-based paradigms might be avoided by using coronary computed tomographic angiography (CCTA) for exclusion of obstructive coronary artery disease. The growth of CCTA has been supported by comparative prognostic evidence with CCTA and functional testing, as well as radiation dose reduction. Use of CCTA for physiological evaluation of coronary lesion-specific ischemia may facilitate evaluation of moderate stenoses, designation of the culprit lesion, and prediction of benefit from revascularization. The potential of CCTA to serve as an effective gatekeeper to invasive coronary angiography will depend, in part, on the adoption of these new developments, as well as definition of the benefit of detecting high-risk plaque for guiding the management of selected patients.

  11. Imaging and graphing of cortical vasculature using dynamically focused optical coherence microscopy angiography

    NASA Astrophysics Data System (ADS)

    Leahy, Conor; Radhakrishnan, Harsha; Bernucci, Marcel; Srinivasan, Vivek J.

    2016-02-01

    Recently, optical coherence tomography (OCT) angiography has enabled label-free imaging of vasculature based on dynamic scattering in vessels. However, quantitative volumetric analysis of the vascular networks depicted in OCT angiography data has remained challenging. Multiple-scattering tails (artifacts specific to the imaging geometry) make automated assessment of vascular morphology problematic. We demonstrate that dynamically focused optical coherence microscopy (OCM) angiography with a high numerical aperture, chosen so the scattering length greatly exceeds the depth-of-field, significantly reduces the deleterious effect of multiple-scattering tails in synthesized angiograms. Capitalizing on the improved vascular image quality, we devised and tailored a self-correcting automated graphing approach that achieves a reconstruction of cortical microvasculature from OCM angiography data sets with accuracy approaching that attained by trained operators. The automated techniques described here will facilitate more widespread study of vascular network topology in health and disease.

  12. Simulation Environment for the Evaluation of 3D Coronary Tree Reconstruction Algorithms in Rotational Angiography

    PubMed Central

    Yang, Guanyu; Bousse, Alexandre; Toumoulin, Christine; Shu, Huazhong

    2007-01-01

    We present a preliminary version of a simulation environment to evaluate the 3D reconstruction algorithms of the coronary arteries in rotational angiography. It includes the construction of a 3D dynamic model of the coronary tree from patient data, the modeling of the rotational angiography acquisition system to simulate different acquisition and gating strategies and the calculation of radiographic projections of the 3D model of coronary tree throughout several cardiac cycles. PMID:18003001

  13. Ultra-wide field angiography in the management of Eales disease

    PubMed Central

    Kumar, Vinod; Chandra, Parijat; Kumar, Atul

    2016-01-01

    Aims: This study aims to evaluate the use of ultra-wide field (UWF) angiography in patients with Eales disease (ED). Settings and Design: Prospective observational case series in tertiary eye care center. Subjects and Methods: This study involved 17 patients diagnosed with ED, who underwent UWF fluorescein angiography. The angiograms were analyzed to look for additional information as compared to Early Treatment Diabetic Retinopathy Study seven standard field. The impact of this information in the management of patients was analyzed. Results: 24 eyes of 17 patients with mean age of 26.3 years were diagnosed with ED and underwent UWF angiography. UWF fluorescein angiography was helpful in the documentation of peripheral retinal changes (in 67% of eyes), exact localization of capillary nonperfusion (CNP) (in 54% of eyes), and in determination of vascular involvement (in 21% of eyes). In 33% of eyes, immediate treatment plan changed because of changes picked up on UWF angiography. Conclusions: UWF angiography helped in the better documentation, exact quantification, and location of CNP areas and better determination of disease activity. UWF imaging may play an important part in the management of patients with ED. PMID:27609162

  14. 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.

  15. 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

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

    PubMed

    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.

  17. 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

  18. 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.

  19. K-Edge Subtraction Angiography with Synchrotron X-Rays

    SciTech Connect

    Giacomini, John C.

    1996-12-31

    The purpose of this project was to utilize dual energy, monochromatic X-rays produced from synchrotrons radiation in order to obtain noninvasive medical imaging. The application of synchrotrons radiation to medical imaging is based on the principle of iodine dichromography, first described by Bertil Jacobson of the Karolinska Institute in 1953. Medical imaging using synchrotrons radiation and K-edge dichromography was pioneered at Stanford University under the leadership of Dr. Ed Rubenstein, and the late Nobel Laureate in Physics, Dr. Robert Hofstadter. With progressive refinements in hardware, clinical-quality images were obtained of human coronary arteries utilizing peripheral injections of iodinated contrast agent. These images even now are far superior to those being presented by investigators using MRI as an imaging tool for coronary arteries. However, new supplies and instruments in the cardiac catheterization laboratory have served to transform coronary angiography into an outpatient procedure, with relatively little morbidity. We extended the principles learned with coronary angiography to noninvasive imaging of the human bronchial tree. For these images, we utilized xenon as the contrast agent, as it has a K-edge very similar to that of iodine. In this case, there is no true competing diagnostic test, and pulmonary neoplasm is an enormous public health concern. In early experiments, we demonstrated remarkably clear images of the human bronchial tree. These images have been shown internationally; however, funding difficulties primarily with the Department of Energy have not allowed for progression of this promising avenue of research. One potential criticism of the project is that in order to obtain these images, we utilized national laboratories. Some have questioned whether this would lead to a practical imaging modality. However, we have shown that the technology exists to allow for construction of a miniature storage ring, with a superconducting

  20. A new protocol using sodium bicarbonate for the prevention of contrast-induced nephropathy in patients undergoing coronary angiography.

    PubMed

    Motohiro, Masayuki; Kamihata, Hiroshi; Tsujimoto, Satoshi; Seno, Takeshi; Manabe, Kenichi; Isono, Tsuyoshi; Sutani, Yasuo; Yuasa, Fumio; Iwasaka, Toshiji

    2011-06-01

    Contrast-induced nephropathy (CIN) is associated with increased morbidity and mortality rates. Although a previous study reported that pretreatment with sodium bicarbonate is more effective than sodium chloride for prophylaxis of CIN, this has not been a universal finding. We performed a prospective randomized trial to investigate whether CIN can be avoided using sodium bicarbonate. In total 155 patients with a glomerular filtration rate (GFR) <60 ml/min/1.73 m(2) who were undergoing coronary angiography were enrolled. We assigned patients to sodium chloride plus sodium bicarbonate (bicarbonate group, n = 78) or sodium chloride alone (chloride group, n = 77). Infusion of sodium bicarbonate at 1 ml/kg/hour continued from 3 hours before to 6 hours after coronary angiography. CIN was defined as a 25% increase in serum creatinine from baseline value or an absolute increase of ≥0.5 mg/dl, which appeared within 2 days of contrast. Baseline GFR was not significantly different between the 2 groups. Patients in the bicarbonate group had a higher GFR than those in the chloride group on day 2 (45.8 ± 13.4 vs 40.9 ± 14.6 ml/min/1.73 m(2), p = 0.031) and at 1 month (49.5 ± 14.7 vs 43.7 ± 15.5 ml/min/1.73 m(2), p = 0.019). CIN occurred in 10 patients (13%) in the chloride group but in only 2 patients (2.6%) in the bicarbonate group (p = 0.012). Sodium chloride plus sodium bicarbonate is more effective than sodium chloride alone for prophylaxis of CIN and can lead to retention of better long-term renal function.

  1. Automatic detection and quantification of the Agatston coronary artery calcium score on contrast computed tomography angiography.

    PubMed

    Ahmed, Wehab; de Graaf, Michiel A; Broersen, Alexander; Kitslaar, Pieter H; Oost, Elco; Dijkstra, Jouke; Bax, Jeroen J; Reiber, Johan H C; Scholte, Arthur J

    2015-01-01

    Potentially, Agatston coronary artery calcium (CAC) score could be calculated on contrast computed tomography coronary angiography (CTA). This will make a separate non-contrast CT scan superfluous. This study aims to assess the performance of a novel fully automatic algorithm to detect and quantify the Agatston CAC score in contrast CTA images. From a clinical registry, 20 patients were randomly selected for each CAC category (i.e. 0, 1-99, 100-399, 400-999, ≥1,000). The Agatston CAC score on non-contrast CT was calculated manually, while the novel algorithm was used to automatically detect and quantify Agatston CAC score in contrast CTA images. The resulting Agatston CAC scores were validated against the non-contrast images. A total of 100 patients (60 ± 11 years, 63 men) were included. The median CAC score on non-contrast CT was 145 (IQR 5-760), whereas the contrast CTA CAC score was 170 (IQR 23-594) (P = 0.004). The automatically computed CAC score showed a high correlation (R = 0.949; P < 0.001) and intra-class correlation (R = 0.863; P < 0.001) with non-contrast CT CAC score. Moreover, agreement within CAC categories was good (κ 0.588). Fully automatic detection of Agatston CAC score on contrast CTA is feasible and showed high correlation with non-contrast CT CAC score. This could imply a radiation dose reduction and time saving by omitting the non-contrast scan. PMID:25159031

  2. 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.

  3. Peri-procedural Glycemic Control in Patients with Diabetes Mellitus Undergoing Coronary Angiography with Possible Percutaneous Coronary Intervention

    PubMed Central

    Shah, Binita; Berger, Jeffrey S.; Amoroso, Nicholas S.; Mai, Xingchen; Lorin, Jeffrey D.; Danoff, Ann; Schwartzbard, Arthur Z.; Lobach, Iryna; Guo, Yu; Feit, Frederick; Slater, James; Attubato, Michael J.; Sedlis, Steven P.

    2014-01-01

    Peri-procedural hyperglycemia is an independent predictor of mortality in patients undergoing percutaneous coronary intervention (PCI). However, peri-procedural management of blood glucose is not standardized. The effects of routinely continuing long-acting glucose-lowering medications prior to coronary angiography with possible PCI on peri-procedural glycemic control have not been investigated. Patients with diabetes mellitus (DM) (n=172) were randomized to continue (Continue group; n=86) or hold (Hold group; n=86) their clinically prescribed long-acting glucose-lowering medications prior to procedure. The primary endpoint was glucose level on procedural access. In a subset of patients (no DM group, n=25, Continue group, n=25, and Hold group, n=25), selected measures of platelet activity that change acutely were assessed. Patients with DM randomized to the Continue group had lower blood glucose levels on procedural access compared with those randomized to the Hold group (117 [97–151] vs 134 [117–172] mg/dL, p=0.002). There were 2 hypoglycemic events in the Continue group and none in the Hold group, and no adverse events in either group. Selected markers of platelet activity differed across the no DM, Continue, and Hold groups (leukocyte platelet aggregates: 8.1% [7.2–10.4], 8.7% [6.9–11.4], 10.9% [8.6–14.7], p=0.007; monocyte platelet aggregates: 14.0% [10.3–16.3], 20.8% [16.2–27.0], 22.5% [15.2–35.4], p<0.001; soluble p-selectin: 51.9ng/mL [39.7–74.0], 59.1ng/mL [46.8–73.2], 72.2ng/mL [58.4–77.4], p=0.014). In conclusion, routinely continuing clinically prescribed long-acting glucose-lowering medications prior to coronary angiography with possible PCI helps achieve peri-procedural euglycemia, appears safe, and should be considered as a strategy for achieving peri-procedural glycemic control. PMID:24630791

  4. Comparison of Standard Catheters Versus Radial Artery-Specific Catheter in Patients Who Underwent Coronary Angiography Through Transradial Access.

    PubMed

    Chen, On; Goel, Sunny; Acholonu, Michael; Kulbak, Guy; Verma, Shivani; Travlos, Efstratios; Casazza, Richard; Borgen, Elliot; Malik, Bilal; Friedman, Michael; Moskovits, Norbert; Frankel, Robert; Shani, Jacob; Ayzenberg, Sergey

    2016-08-01

    In this prospective, randomized controlled study, we aim to compare the performance outcomes of standard catheters with the radial artery-specific catheter. Over the past decade, transradial cardiac catheterization has gained widespread popularity because of its low complication rates compared with transfemoral access. Operators have the choice of using either standard catheters (used for both transfemoral and transradial approach, with need for separate catheter use for either right or left coronary artery engagement) or a dedicated radial artery catheter, which is specifically designed to engage both coronary arteries through radial artery access. A total of 110 consecutive patients who underwent coronary angiography at our institution from March 2015 to April 2015 were prospectively randomized to either radial artery-specific Tiger catheter (5Fr; Terumo Interventional Systems, Somerset, New Jersey) versus standard Judkins left and right catheters (5Fr R4, L4; Cordis Corporation, Miami, Florida). The end points of the study included fluoroscopy time, dose-area product, contrast volume used, and total procedure time for the coronary angiography. A total of 57 patients (52%) were randomized to radial artery-specific catheter and 53 (48%) to the standard catheter. Tiger catheter was associated with significantly lower fluoroscopy time (184 ± 91 vs 238 ± 131 seconds, p = 0.015), which was statistically significant. Other outcome measures such as dose-area product (2,882.4 ± 1,471.2 vs 3,524.6 ± 2,111.7 Gy·cm(2), p = 0.07), total contrast volume (48.1 ± 16.1 vs 53.4 ± 18.5 ml, p = 0.114), and total procedure time (337 ± 382 vs 434 ± 137 seconds, p = 0.085) were also lower in single-catheter group, but it did not reach statistical significance. A total of 8 patients (14%) were crossed over from radial-specific catheter arm to standard catheter arm because of substandard image quality and difficulty in coronary engagement. Six patients had to be

  5. Etiologic exploration of magnetic resonance tomographic angiography negative trigeminal neuralgia.

    PubMed

    Zhang, Wenhao; Chen, Minjie; Zhang, Weijie; Chai, Ying

    2014-08-01

    Our objective was to explore the etiologic factors involved in trigeminal neuralgia with negative magnetic resonance tomographic angiography (MRTA) results. Clinical data from 341 patients with idiopathic trigeminal neuralgia who were treated with neurovascular decompression between March 2003 and December 2011 were retrospectively analyzed. The etiologic causes of preoperative MRTA-negative trigeminal neuralgia were categorized based on comparisons between preoperative MRTA and intraoperative endoscopic images. MRTA was highly sensitive (92.4%, 291/315) to neurovascular compression, whereas its specificity was 65.4% (17/26). Among the 24 false-negative cases, there were nine patients with petrosal vein compression, 12 with superior cerebellar artery compression, two with superior cerebellar arterial branch compression, and one patient with anterior inferior cerebellar artery compression. Among the 17 true-negative cases, three patients had arachnoid adhesions, one had a protruding temporal eminence, five had micro-cholesteatomas, and eight patients exhibited no compression. The factors responsible for the MRTA-negative results included small-diameter arterial vessels, veins with slow blood flow, arachnoid adhesions, protruding temporal eminences, micro-cholesteatomas, and other pathologies such as multiple sclerosis. Preoperative diagnoses of MRTA-negative patients need to integrate the MRI results from multiple sequences to discriminate between arteriolar compression, venous compression, and small compressive lesions. When narrow cerebellopontine angles are shown in MRTA, arachnoid adhesion and temporal eminence compression should be considered. PMID:24758727

  6. Time-resolved MR angiography with limited projections.

    PubMed

    Huang, Yuexi; Wright, Graham A

    2007-08-01

    A method for reconstruction of time-resolved MRI called highly-constrained backprojection (HYPR) has been developed. To evaluate the HYPR reconstruction in relation to data sparsity and temporal dynamics, computer simulations were performed, investigating signal modulations under different situations that reflect dynamic contrast-enhanced MR angiography (MRA). In vivo studies were also performed with gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) for abdominal MRA in a canine model to demonstrate the application of HYPR for three-dimensional (3D) time-resolved MRA. When contrast dynamics vary over space, large vessels (e.g., veins) tend to introduce signal interference to small vessels (e.g., arteries) in HYPR, particularly when the vessels are in close proximity. The enhancement of background tissue signals may also alter the arterial and venous temporal profiles in HYPR. However, the artifacts are manifest as intensity modulation rather than structural interference, and therefore have little impact on structural diagnosis. Increasing the number of projections per time point increases temporal blur while reducing corruption of temporal behavior from adjacent tissues. Uniformly interleaved acquisition order, such as the bit-reversed order, is important to reduce artifacts. With high signal-to-noise ratio (SNR) and limited artifacts, HYPR reconstruction has potential to greatly improve time-resolved MRA in clinical practice.

  7. Acquisition-related motion compensation for digital subtraction angiography.

    PubMed

    Ionasec, Razvan Ioan; Heigl, Benno; Hornegger, Joachim

    2009-06-01

    Subtraction methods in angiography are generally applied in order to enhance the visualization of blood vessels by eliminating bones and surrounding tissues from X-ray images. The main limitation of these methods is the sensitivity to patient movement, which leads to artifacts and reduces the clinical value of the subtraction images. In this paper we present a novel method for rigid motion compensation with primary application to road mapping, frequently used in image-guided interventions. Using the general concept of image-based registration, we optimize the physical position and orientation of the C-arm X-ray device, thought of as the rigid 3D transformation accounting for the patient movement. The registration is carried out using a hierarchical optimization strategy and a similarity measure based on the variance of intensity differences, which has been shown to be most suitable for fluoroscopic images. Performance evaluation demonstrated the capabilities of the proposed approach to compensate for potential intra-operative patient motion, being more resilient to the fundamental problems of pure image-based registration.

  8. 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

  9. Assessment of the Circle of Willis with Cranial Tomography Angiography

    PubMed Central

    Karatas, Ayse; Coban, Gokmen; Cinar, Celal; Oran, Ismail; Uz, Aysun

    2015-01-01

    Background The circle of Willis is a major collateral pathway important in ischemic conditions. The aim of our study was to assess the structural characteristics of the circle of Willis within the Turkish adult population, along with variations and arteries involved in the measurement of diameters and lengths on cranial computed tomography angiography (CTA). Material/Methods One hundred adult patients who underwent CTA images were evaluated retrospectively. Results Results of the study revealed 82% adult, 17% fetal, and 1% transitional configurations. A complete polygonal structure was observed in 28% of cases. Variations of the circle of Willis were more common in the posterior portion. Hypoplasia was found to be the most common variation and was observed as a maximum in the posterior communicating artery (AComP). Conclusions The patency and size of arteries in the circle of Willis are important in occlusive cerebrovascular diseases and cerebrovascular surgery. Although CTA is an easily accessible non-invasive clinical method for demonstrating the vascular structure, CTA should be evaluated taking into account image resolution quality and difficulties in the identification of small vessels. PMID:26343887

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

    NASA Astrophysics Data System (ADS)

    Gmür, 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.

  11. Intraoperative Indocyanine Green Laser Angiography in Pediatric Autologous Ear Reconstruction

    PubMed Central

    Martins, Deborah B.; Farias-Eisner, Gina; Mandelbaum, Rachel S.; Hoang, Han; Bradley, James P.

    2016-01-01

    Summary: Skin flap vascularity is a critical determinant of aesthetic results in autologous ear reconstruction. In this study, we investigate the use of intraoperative laser-assisted indocyanine green angiography (ICGA) as an adjunctive measure of skin flap vascularity in pediatric autologous ear reconstruction. Twenty-one consecutive pediatric patients undergoing first-stage autologous total ear reconstruction were retrospectively evaluated. The first 10 patients were treated traditionally (non-ICGA), and the latter 11 patients were evaluated with ICGA intraoperatively after implantation of the cartilage construct and administration of suction. Relative and absolute perfusion units in the form of contour maps were generated. Statistical analyses were performed using independent sample Student t test. Statistically significant differences in exposure and infection were not found between the 2 groups. However, decreased numbers of surgical revisions were required in cases with ICGA versus without ICGA (P = 0.03), suggesting that greater certainty in skin flap perfusion correlated with a reduction in revision surgeries. In cases of exposure, we found an average lowest absolute perfusion unit of 14.3, whereas cases without exposure had an average of 26.1 (P = 0.02), thereby defining objective parameters for utilizing ICGA data in tailoring surgical decision making for this special population of patients. Defined quantitative parameters for utilizing ICGA in evaluating skin flap vascularity may be a useful adjunctive technique in pediatric autologous ear reconstruction. PMID:27579233

  12. Semiautomatic bone removal technique from CT angiography data

    NASA Astrophysics Data System (ADS)

    Alyassin, Abdal M.; Avinash, Gopal B.

    2001-07-01

    Cortical bone is the major barrier in visualizing the 3-D blood vessel tree from CT Angiography [CTA] data. Thus, we have developed a novel semi-automatic technique that removes the cortical bone and retains the clinical diagnostic information such as blood vessels, aneurysms, and calcifications. The technique is based on a methodical composite set of filters that use region-growing, adaptive, and morphological filtering algorithms. While using only voxel intensity value and region size information, this technique retains most of the CTA data untouched. We have implemented this method on 10 CTA abdomen and head data sets. The accuracy of the method was tested and proved successful by visual inspection of all segmented slices. The segmented CTA data were also visualized in 3-D with different Ray Casting Volume Rendering techniques (e.g. Maximum Intensity Projection). The blood vessels along with other diagnostic information were clearly visualized in 3-D without the obstruction of bone. The segmentation technique ran under one second per slice (image size is 512x512x2 bytes) on a PC with 550 MHz processor.

  13. Optimized radiographic spectra for small animal digital subtraction angiography

    SciTech Connect

    De Linming; Samei, Ehsan; Badea, Cristian T.; Yoshizumi, Terry T.; Allan Johnson, G.

    2006-11-15

    The increasing use of small animals in basic research has spurred interest in new imaging methodologies. Digital subtraction angiography (DSA) offers a particularly appealing approach to functional imaging in the small animal. This study examines the optimal x-ray, molybdenum (Mo) or tungsten (W) target sources, and technique to produce the highest quality small animal functional subtraction angiograms in terms of contrast and signal-difference-to-noise ratio squared (SdNR{sup 2}). Two limiting conditions were considered--normalization with respect to dose and normalization against tube loading. Image contrast and SdNR{sup 2} were simulated using an established x-ray model. DSA images of live rats were taken at two representative tube potentials for the W and Mo sources. Results show that for small animal DSA, the Mo source provides better contrast. However, with digital detectors, SdNR{sup 2} is the more relevant figure of merit. The W source operated at kVps>60 achieved a higher SdNR{sup 2}. The highest SdNR{sup 2} was obtained at voltages above 90 kVp. However, operation at the higher potential results in significantly greater dose and tube load and reduced contrast quantization. A reasonable tradeoff can be achieved at tube potentials at the beginning of the performance plateau, around 70 kVp, where the relative gain in SdNR{sup 2} is the greatest.

  14. Intraoperative Indocyanine Green Laser Angiography in Pediatric Autologous Ear Reconstruction.

    PubMed

    Martins, Deborah B; Farias-Eisner, Gina; Mandelbaum, Rachel S; Hoang, Han; Bradley, James P; Lee, Justine C

    2016-05-01

    Skin flap vascularity is a critical determinant of aesthetic results in autologous ear reconstruction. In this study, we investigate the use of intraoperative laser-assisted indocyanine green angiography (ICGA) as an adjunctive measure of skin flap vascularity in pediatric autologous ear reconstruction. Twenty-one consecutive pediatric patients undergoing first-stage autologous total ear reconstruction were retrospectively evaluated. The first 10 patients were treated traditionally (non-ICGA), and the latter 11 patients were evaluated with ICGA intraoperatively after implantation of the cartilage construct and administration of suction. Relative and absolute perfusion units in the form of contour maps were generated. Statistical analyses were performed using independent sample Student t test. Statistically significant differences in exposure and infection were not found between the 2 groups. However, decreased numbers of surgical revisions were required in cases with ICGA versus without ICGA (P = 0.03), suggesting that greater certainty in skin flap perfusion correlated with a reduction in revision surgeries. In cases of exposure, we found an average lowest absolute perfusion unit of 14.3, whereas cases without exposure had an average of 26.1 (P = 0.02), thereby defining objective parameters for utilizing ICGA data in tailoring surgical decision making for this special population of patients. Defined quantitative parameters for utilizing ICGA in evaluating skin flap vascularity may be a useful adjunctive technique in pediatric autologous ear reconstruction. PMID:27579233

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Segmental Comparison of Peripheral Arteries by Doppler Ultrasound and CT Angiography

    PubMed Central

    Swaminathan, Ram Kumar; Ganesan, Prakash; Mayavan, Manibharathi

    2016-01-01

    Introduction Diseases of peripheral arterial system are one of the common causes of limb pain, especially in elderly patients. Here we analyse non invasive imaging of peripheral arterial segments. Aim Aim of the study was to compare arterial diseases of extremities using Doppler ultrasound and CT angiography, and to find the better non-invasive modality of choice. Materials and Methods Fifty patients {14 patients with upper limb complaints (15 upper limbs) and 36 patients with lower limb complaints (72 lower limbs)} of peripheral arterial disease underwent Doppler ultrasound (USG) and CT Angiogram (CTA). Arterial systems divided into anatomic segments and luminal narrowing were compared using gray scale Doppler ultrasound and axial images of arterial phase of CT angiogram. Using statistical methods, sensitivity, specificity and accuracy of Doppler ultrasound and CT angiography were determined. Results Six hundred and nineteen arterial segments were studied with CT angiography and Doppler ultrasound. Of which 226 diseased segments were identified in CT angiography. Doppler overestimated narrowing by one grade in 47 segments, by two grade in 11 segments, by three grades in 30 segments and by four grades in 22 segments; underestimated by one grade in 28 segments, by two grades in 9 segments, by three grades in 5 segments and by four grades in 3 segments. Significant statistical difference exists between Doppler USG and CT angiography. Doppler showed good correlation with CT angiography in 74%, but, Doppler overestimated stenosis grade in a significant percentage. The sensitivity, specificity and accuracy of Doppler USG compared with CT angiography was 93.36%, 82.44%, and 86.42%. Conclusion Duplex Doppler can be the first investigation in excluding peripheral arterial disease, especially for evaluation of infra inguinal region of lower limbs and from second part of the subclavian artery in upper limbs. PMID:27042556

  20. Predictive parameters for angiography and embolization in the bleeding pelvic fracture

    PubMed Central

    Anandakumar, V.; Hussein, Fareed K.; Varuun, B.; Zhu, R.

    2013-01-01

    Aim In the bleeding pelvic fracture, decision needs to be made on definitive control of bleeding whilst resuscitation. The decision for angiography in unstable patients is difficult and this study hopes to identify the parameters that may aid in this decision. Methods 121 patients with traumatic pelvic fractures were identified from June 2005 till June 2010, from the National University Hospital, Singapore. Out of these 121 patients, 15 patients who underwent angiographic evaluation were identified. 11 out of the 15 had angiography and embolization done, while the remaining 4 only had angiography done. Another group of 29 patients who had not undergone angiography were identified from the main population via age-matched criteria. Clinical parameters were compared between the 15 angiography patients and the 29 non-angiography group of patients. Results Angiography group had a larger proportion (80%) with contrast blush noted on contrast-enhanced CT scan (CECT), a higher proportion with unstable pelvic fracture patterns as classified by Tile (80%), and Young and Burgess (92.4%) (p < 0.05). Embolized group had higher proportion (81.8%) with hematoma and with blush on CECT (100%), and higher proportion with unstable fracture patterns (UFPs) (72.7%) as classified by Tile (p < 0.05). Positive predictive value for embolization using hematoma alone is 39% while that of blush alone is 73% and unstable Tile fracture alone is 47%. Positive predictive value of combined hematoma, blush and unstable Tile fracture pattern is 75%. Conclusion Significant predictive factors for angiogram would be unstable pelvic fracture patterns, presence of hematoma and contrast blushing on CT. PMID:26403627

  1. Complications of cerebral angiography for patients with mild carotid territory ischaemia being considered for carotid endarterectomy.

    PubMed Central

    Hankey, G J; Warlow, C P; Molyneux, A J

    1990-01-01

    It is essential to image the carotid bifurcation adequately in patients with symptomatic carotid territory ischaemia if they are being considered for carotid endarterectomy. Optimal resolution is achieved by selective intraarterial contrast angiography which is an invasive procedure carrying some risk. The overall risk-benefit of carotid endarterectomy is currently being investigated in several large randomised trials in Europe and North America. Because cerebral angiography is a prerequisite for carotid endarterectomy, the risks of cerebral angiography will need to be added to those of surgery when considering whether carotid endarterectomy is effective in the management of these patients. This study evaluated prospectively 382 patients with symptomatically mild carotid ischaemia who had cerebral angiography to visualise a potentially resectable lesion at the carotid bifurcation. Complications followed 14 cerebral angiograms in 13 patients (3.4%); two complications were local (0.5%), two systemic (0.5%) and 10 were neurological (2.6%). The neurological complications were transient (TIA 1, generalised seizure 1) in two patients (0.5%), reversible (stroke) in three (0.8%) and permanent (stroke) in five patients (1.3%). There were no deaths. The significant risk factors for post angiographic stroke were (1) stroke before angiography compared with transient ischaemic attacks of the eye or brain and (2) the presence of greater than or equal to 50% diameter stenosis of the symptomatic internal carotid artery; unfortunately it may be the latter patients who are most at risk of stroke as part of the natural history of their disease and therefore most in need of prophylactic carotid endarterectomy (which requires cerebral angiography). The absolute risk of post-angiographic stroke of patients for cerebral angiography using clinical evaluation and Duplex carotid ultrasound screening. PMID:2118171

  2. Angiography reveals novel features of the retinal vasculature in healthy and diabetic mice.

    PubMed

    McLenachan, Samuel; Magno, Aaron Len; Ramos, David; Catita, Joana; McMenamin, Paul G; Chen, Fred Kuanfu; Rakoczy, Elizabeth Piroska; Ruberte, Jesus

    2015-09-01

    The mouse retina is a commonly used animal model for the study of pathogenesis and treatment of blinding retinal vascular diseases such as diabetic retinopathy. In this study, we aimed to characterize normal and pathological variations in vascular anatomy in the mouse retina using fluorescein angiography visualized with scanning laser ophthalmoscopy and optical coherence tomography (SLO-OCT). We examined eyes from C57BL/6J wild type mice as well as the Ins2(Akita) and Akimba mouse models of diabetic retinopathy using the Heidelberg Retinal Angiography (HRA) and OCT system. Angiography was performed on three focal planes to examine distinct vascular layers. For comparison with angiographic data, ex vivo analyses, including Indian ink angiography, histology and 3D confocal scanning laser microscopy were performed in parallel. All layers of the mouse retinal vasculature could be readily visualized during fluorescein angiography by SLO-OCT. Blood vessel density was increased in the deep vascular plexus (DVP) compared with the superficial vascular plexus (SVP). Arteriolar and venular typologies were established and structural differences were observed between venular types. Unexpectedly, the hyaloid artery was found to persist in 15% of C57BL/6 mice, forming anastomoses with peripheral retinal capillaries. Fluorescein leakage was easily detected in Akimba retinae by angiography, but was not observed in Ins2(Akita) mice. Blood vessel density was increased in the DVP of 6 month old Ins2(Akita) mice, while the SVP displayed reduced branching in precapillary arterioles. In summary, we present the first comprehensive characterization of the mouse retinal vasculature by SLO-OCT fluorescein angiography. Using this clinical imaging technique, we report previously unrecognized variations in C57BL/6J vascular anatomy and novel features of vascular retinopathy in the Ins2(Akita) mouse model of diabetes.

  3. Diagnostic accuracy and implementation of computed tomography angiography for gastrointestinal hemorrhage according to clinical severity

    PubMed Central

    Choi, Yoo Jin; Kim, Kyung Su; Suh, Gil Joon; Kwon, Woon Yong

    2016-01-01

    Objective This study compared the diagnostic accuracy of computed tomography (CT) angiography in patients with various severities of gastrointestinal hemorrhage (GIH). Methods We retrospectively enrolled adult patients (n=262) with GIH who had undergone CT angiography from January 2012 to December 2013. Age, sex, comorbidities, presenting symptoms, initial vital signs, laboratory results, transfusion volume, emergency department disposition, and hospital mortality were abstracted from patient records. CT angiography findings were reviewed and compared to reference standards consisting of endoscopy, conventional angiography, bleeding scan, capsule endoscopy, and surgery, either alone or in combination. Clinical severity was stratified according to the number of packed red blood cell units transfused during the first two days: the first quartile was categorized as mild severity, while the second and third quartiles were categorized as moderate severity. The fourth quartile was categorized as severe. Results Patients were categorized into the mild (n=75, 28.6%), moderate (n=139, 53.1%), and severe (n=48, 18.3%) groups. The mean number of transfused packed red blood cell units was 0, 3, and 9.6 in the mild, moderate, and severe groups, respectively. The overall sensitivity, specificity, positive predictive value, and negative predictive value of CT angiography were 73.8%, 94.0%, 97.3%, and 55.3%, respectively. The area under the receiver operating characteristics curve for the diagnostic performance of CT angiography was 0.780, 0.841, and 0.930 in the mild, moderate, and severe groups, respectively, which significantly differed among groups (P=0.006). Conclusion The diagnostic accuracy of CT angiography is better in patients with more severe GIH. PMID:27752620

  4. Development of a theory for generating regional cardiac perfusion images during coronary angiography in the coronary angiography lab.

    PubMed

    Sakaguchi, Takuya; Ichihara, Takashi; Trost, Jeffrey C; Yousuf, Omair; Lima, Joao A C; Yao, Jingwu; George, Richard T

    2014-01-01

    The purpose of this study was to develop a novel theory and method for generating regional myocardial perfusion images using fluoroscopy in the coronary angiography lab. We modified the Kety model to introduce the Patlak plot method for two-dimensional fluoroperfusion (FP) imaging. For evaluation, seven porcine models of myocardial ischemia with stenosis in the left coronary artery were prepared. Rest and stress FP imaging were performed using cardiovascular X-ray imaging equipment during the injection of iopamidol via the left main coronary artery. Images were acquired and retrospectively ECG gated at 80 % of the R-R interval. FP myocardial blood flow (MBF) was obtained using the Patlak plot method applied to time-intensity curve data of the proximal artery and myocardium. The results were compared to microsphere MBF measurements. Time-intensity curves were also used to generate color-coded FP maps. There was a moderate linear correlation between the calculated FP MBF and the microsphere MBF (y = 0.9758x + 0.5368, R² = 0.61). The color-coded FP maps were moderately correlated with the regional distribution of flow. This novel method of first-pass contrast-enhanced two-dimensional fluoroscopic imaging can quantify MBF and provide color coded FP maps representing regional myocardial perfusion.

  5. 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

  6. Heidelberg Spectralis Optical Coherence Tomography Angiography: Technical Aspects.

    PubMed

    Coscas, Gabriel; Lupidi, Marco; Coscas, Florence

    2016-01-01

    Optical coherence tomography angiography (OCT-A) is a promising new method for visualizing the retinal vasculature and choroidal vascular layers in the macular area and provides depth-resolved functional information on blood flow in these vessels. OCT-A is based on the concept that in a static eye the only moving structure in the fundus of the eye is blood flowing through the vessels. Contrast is generated based on the difference between moving cells in the vasculature and the static surrounding tissue. Artifacts can arise due to scan positioning errors caused by normal ocular microsaccades. In order to avoid artifacts, a sequence of OCT B-scans in the exact same retinal location must be taken to detect flow. Active eye-tracking (TruTrack™) using the simultaneous acquisition of fundus and optical coherence tomography (OCT) images presents a very reliable method of acquiring OCT volume scans without motion artifacts and helps significantly improve signal-to-noise ratio. This system also allows the use of a full spectrum amplitude decorrelation algorithm that produces clear differentiation between blood flow and static tissue without sacrificing the axial resolution of OCT images. Accuracy in layer segmentation, which requires high-resolution OCT B-scans, is crucial for producing reliable OCT-A images. This can be achieved through automated or manual layer segmentation. During OCT scan acquisition, the effect of axial motion (e.g. a patient moving towards the camera) is compensated for by geometric alignment of successive B-scans before analyzing temporal changes.

  7. Ultra Low Dose CT Pulmonary Angiography with Iterative Reconstruction

    PubMed Central

    Koehler, Thomas; Fingerle, Alexander A.; Brendel, Bernhard; Richter, Vivien; Rasper, Michael; Rummeny, Ernst J.; Noël, Peter B.; Münzel, Daniela

    2016-01-01

    Objective Evaluation of a new iterative reconstruction algorithm (IMR) for detection/rule-out of pulmonary embolism (PE) in ultra-low dose computed tomography pulmonary angiography (CTPA). Methods Lower dose CT data sets were simulated based on CTPA examinations of 16 patients with pulmonary embolism (PE) with dose levels (DL) of 50%, 25%, 12.5%, 6.3% or 3.1% of the original tube current setting. Original CT data sets and simulated low-dose data sets were reconstructed with three reconstruction algorithms: the standard reconstruction algorithm “filtered back projection” (FBP), the first generation iterative reconstruction algorithm iDose and the next generation iterative reconstruction algorithm “Iterative Model Reconstruction” (IMR). In total, 288 CTPA data sets (16 patients, 6 tube current levels, 3 different algorithms) were evaluated by two blinded radiologists regarding image quality, diagnostic confidence, detectability of PE and contrast-to-noise ratio (CNR). Results iDose and IMR showed better detectability of PE than FBP. With IMR, sensitivity for detection of PE was 100% down to a dose level of 12.5%. iDose and IMR showed superiority to FBP regarding all characteristics of subjective (diagnostic confidence in detection of PE, image quality, image noise, artefacts) and objective image quality. The minimum DL providing acceptable diagnostic performance was 12.5% (= 0.45 mSv) for IMR, 25% (= 0.89 mSv) for iDose and 100% (= 3.57 mSv) for FBP. CNR was significantly (p < 0.001) improved by IMR compared to FBP and iDose at all dose levels. Conclusion By using IMR for detection of PE, dose reduction for CTPA of up to 75% is possible while maintaining full diagnostic confidence. This would result in a mean effective dose of approximately 0.9 mSv for CTPA. PMID:27611830

  8. Intracranial arterial variations: A comprehensive evaluation using CT angiography

    PubMed Central

    Kovač, Jelena Djokić; Stanković, Ana; Stanković, Danilo; Kovač, Bojan; Šaranović, Djordjije

    2014-01-01

    Background Intracranial arterial variations are a frequent finding in the general population. Knowledge of these vascular variations has significant clinical impact because some of them predispose patients to development of an aneurysm or cerebrovascular ischemic disease. The purpose of this study was to evaluate the frequency of intracranial vascular variations and associated vascular lesions on computed tomography angiography (CTA) examinations. Material/Methods CTA examinations performed by 16-detector computed tomography were prospectively reviewed in 455 patients for the presence of fenestrations, duplications, hypoplasia, aplasia, aneurysms, and other vascular lesions. Results Arterial fenestrations were found in 2.4% of patients, with the vertebrobasilar system as the most common location. The remaining fenestrations were located on the middle cerebral artery M1 segment (0.2%), anterior communicating artery (0.4%), and anterior cerebral artery A1 segment (0.6%). No associated aneurysms were noted in these patients. The prevalence of an azygos anterior cerebral artery was 1.5%. Bihemispheric anterior cerebral artery was found in 0.9%, hypoplastic A1 segment in 17.6%, and congenital absence of A1 segment in 0.4% of patients. Fetal origin of the posterior cerebral artery was found in 37% of cases. Hypoplastic vertebral artery terminating as posterior inferior cerebellar artery was observed in 9 patients, while transversal anastomosis between vertebral arteries was seen in only 1 patient. Conclusions CTA precisely demonstrates the diversity of intracranial arterial variations, whose overall frequency in this study is similar to previous radiological reports. Furthermore, our results do not show significant association between the frequency of aneurysms and cerebral arterial anomalies. PMID:24625840

  9. 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.

  10. 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

  11. CT Pulmonary Angiography: Increasingly Diagnosing Less Severe Pulmonary Emboli

    PubMed Central

    Schissler, Andrew J.; Rozenshtein, Anna; Kulon, Michal E.; Pearson, Gregory D. N.; Green, Robert A.; Stetson, Peter D.; Brenner, David J.; D'Souza, Belinda; Tsai, Wei-Yann; Schluger, Neil W.; Einstein, Andrew J.

    2013-01-01

    Background It is unknown whether the observed increase in computed tomography pulmonary angiography (CTPA) utilization has resulted in increased detection of pulmonary emboli (PEs) with a less severe disease spectrum. Methods Trends in utilization, diagnostic yield, and disease severity were evaluated for 4,048 consecutive initial CTPAs performed in adult patients in the emergency department of a large urban academic medical center between 1/1/2004 and 10/31/2009. Transthoracic echocardiography (TTE) findings and peak serum troponin levels were evaluated to assess for the presence of PE-associated right ventricular (RV) abnormalities (dysfunction or dilatation) and myocardial injury, respectively. Statistical analyses were performed using multivariate logistic regression. Results 268 CTPAs (6.6%) were positive for acute PE, and 3,780 (93.4%) demonstrated either no PE or chronic PE. There was a significant increase in the likelihood of undergoing CTPA per year during the study period (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.04–1.07, P<0.01). There was no significant change in the likelihood of having a CTPA diagnostic of an acute PE per year (OR 1.03, 95% CI 0.95–1.11, P = 0.49). The likelihood of diagnosing a less severe PE on CTPA with no associated RV abnormalities or myocardial injury increased per year during the study period (OR 1.39, 95% CI 1.10–1.75, P = 0.01). Conclusions CTPA utilization has risen with no corresponding change in diagnostic yield, resulting in an increase in PE detection. There is a concurrent rise in the likelihood of diagnosing a less clinically severe spectrum of PEs. PMID:23776522

  12. 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.

  13. Diagnosis of pulmonary embolism with CT pulmonary angiography: a systematic review

    PubMed Central

    Hogg, K; Brown, G; Dunning, J; Wright, J; Carley, S; Foex, B; Mackway‐Jones, K

    2006-01-01

    Objective To appraise the evidence on the diagnostic accuracy of CT pulmonary angiography and the prognostic value of a negative CT pulmonary angiogram in the diagnosis of pulmonary embolism. Methods Medline, EMBASE, and grey literature were systematically searched by two researchers. Any study which compared CT pulmonary angiography to an acceptable reference standard or prospectively followed up a cohort of patients with a normal CT pulmonary angiogram was included. Study methods were appraised independently by two researchers, and data were extracted independently by three researchers. Results Thirteen diagnostic and 11 follow up studies were identified. Studies varied in prevalence of pulmonary embolism (19–79%), patient groups, and method quality. Few studies recruited unselected emergency department patients. There was heterogeneity in the analysis of sensitivity (53 to 100%), specificity (79 to 100%), and false negative rate (1.0 to 10.7%). The pooled false negative rate of combined negative CT pulmonary angiography and negative deep vein thrombosis testing was 1.5% (95% CI 1.0 to 1.9%). Conclusion Diagnostic studies give conflicting results for the diagnostic accuracy of CT pulmonary angiography. Follow up studies show that CT pulmonary angiography can be used in combination with investigation for deep vein thrombosis to exclude pulmonary embolism. PMID:16498151

  14. Synchrotron-based intravenous cerebral angiography in a small animal model

    NASA Astrophysics Data System (ADS)

    Kelly, Michael E.; Schültke, Elisabeth; Fiedler, Stephan; Nemoz, Christian; Guzman, Raphael; Corde, Stephanie; Esteve, Francois; LeDuc, Geraldine; Juurlink, Bernhard H. J.; Meguro, Kotoo

    2007-02-01

    K-edge digital subtraction angiography (KEDSA), a recently developed synchrotron-based technique, utilizes monochromatic radiation and allows acquisition of high-quality angiography images after intravenous administration of contrast agent. We tested KEDSA for its suitability for intravenous cerebral angiography in an animal model. Adult male New Zealand rabbits were subjected to either angiography with conventional x-ray equipment or synchrotron-based intravenous KEDSA, using an iodine-based contrast agent. Angiography with conventional x-ray equipment after intra-arterial administration of contrast agent demonstrated the major intracranial vessels but no smaller branches. KEDSA was able to visualize the major intracranial vessels as well as smaller branches in both radiography mode (planar images) and tomography mode. Visualization was achieved with as little as 0.5 ml kg-1 of iodinated contrast material. We were able to obtain excellent visualization of the cerebral vasculature in an animal model using intravenous injection of contrast material, using synchrotron-based KEDSA.

  15. 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. PMID:24819799

  16. Trigeminocardiac reflex caused by selective angiography of the middle meningeal artery.

    PubMed

    Tamura, Takamitsu; Rex, David E; Marosfoi, Miklos G; Puri, Ajit S; Gounis, Matthew J; Wakhloo, Ajay K

    2016-01-01

    We describe an interesting case of trigeminocardiac reflex (TCR) caused by selective angiography of the middle meningeal artery (MMA). A 28-year-old woman presented with a symptomatic meningioma. Preoperative tumour embolisation was performed. In the procedure, when selective MMA angiography was done with Omnipaque 300 mg I/mL for 3 mL by manual injection, the patient complained of flashing lights in her eye followed by vomiting and bradycardia down to 40 bpm without increased intracranial pressure signs. On selective MMA angiography, the choroidal crescent and arteries of the periorbital region were opacified by anastomosis from the MMA via the meningo-ophthalmic artery. We diagnosed that her symptoms were caused by selective MMA angiography leading to high pressure stimulation towards the ophthalmic nerve innervation around the orbit as a TCR. We suggest that the operator should be prepared to manage TCR during treatment with expected selective MMA angiography, and gentle low pressure contrast injection should be attempted. PMID:27382015

  17. Parathyroid gland angiography with indocyanine green fluorescence to predict parathyroid function after thyroid surgery

    PubMed Central

    Vidal Fortuny, J.; Belfontali, V.; Sadowski, S. M.; Karenovics, W.; Guigard, S.

    2016-01-01

    Background Postoperative hypoparathyroidism remains the most common complication following thyroidectomy. The aim of this pilot study was to evaluate the use of intraoperative parathyroid gland angiography in predicting normal parathyroid gland function after thyroid surgery. Methods Angiography with the fluorescent dye indocyanine green (ICG) was performed in patients undergoing total thyroidectomy, to visualize vascularization of identified parathyroid glands. Results Some 36 patients underwent ICG angiography during thyroidectomy. All patients received standard calcium and vitamin D supplementation. At least one well vascularized parathyroid gland was demonstrated by ICG angiography in 30 patients. All 30 patients had parathyroid hormone (PTH) levels in the normal range on postoperative day (POD) 1 and 10, and only one patient exhibited asymptomatic hypocalcaemia on POD 1. Mean(s.d.) PTH and calcium levels in these patients were 3·3(1·4) pmol/l and 2·27(0·10) mmol/l respectively on POD 1, and 4·0(1.6) pmol/l and 2·32(0·08) mmol/l on POD 10. Two of the six patients in whom no well vascularized parathyroid gland could be demonstrated developed transient hypoparathyroidism. None of the 36 patients presented symptomatic hypocalcaemia, and none received treatment for hypoparathyroidism. Conclusion PTH levels on POD 1 were normal in all patients who had at least one well vascularized parathyroid gland demonstrated during surgery by ICG angiography, and none required treatment for hypoparathyroidism. PMID:26864909

  18. How to Do Random Allocation (Randomization)

    PubMed Central

    Shin, Wonshik

    2014-01-01

    Purpose To explain the concept and procedure of random allocation as used in a randomized controlled study. Methods We explain the general concept of random allocation and demonstrate how to perform the procedure easily and how to report it in a paper. PMID:24605197

  19. 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

  20. Application of intelligent optimal kV scanning technology (CARE kV) in dual-source computed tomography (DSCT) coronary angiography.

    PubMed

    Zhang, Jun; Kang, Shaolei; Han, Dan; Xie, Xiaojie; Deng, Yaming

    2015-01-01

    This study aims to evaluate the applications and values of dual-source computed tomography (DSCT) intelligent optimal kV scanning technology (CARE kV) in coronary CT angiography (CCTA). 150 patients with normal body mass index were performed DSCT coronary angiography, then randomly divided into the "Semi", 120,100 and 80 kV Group, and the 2 "on" groups, with 30 patients in each group. The first 5 groups used the reference voltage as 120 kV, and the reference current as 400 mAs, while the other group used the reference voltage as 100 kV, and the reference current as 400 mAs. The image quality, average CT value, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and radiation dose were comparatively analyzed among the 5 groups. The image quality scores of the five groups showed no significant difference (P > 0.05); the average CT values and image noises had significance (P < 0.05), while SNR and CNR showed no significant difference (P > 0.05). The 80 kV group showed the biggest noise, with the CT value as 700 HU, while the radiation dose was the lowest, followed by the on group. As for the patients with normal body mass index (BMI), CARE kV-"on" could obtain high-quality images and lower radiation dose for CCTA, while the operation was simple and convenient.

  1. The Inflammatory Response to Femoral Arterial Closure Devices: A Randomized Comparison Among FemoStop, AngioSeal, and Perclose

    SciTech Connect

    Jensen, Jens Saleh, Nawzad; Jensen, Ulf; Svane, Bertil; Joensson, Anders; Tornvall, Per

    2008-07-15

    The objectives of this study were to investigate whether the systemic inflammatory response differs, in patients undergoing coronary angiography, among the arterial closure devices FemoStop, AngioSeal, and Perclose. The study is a prospective and randomized study. We measured pre- and postprocedural C-reactive protein (CRP), fibrinogen, and interleukin-6 (IL-6) plasma levels and collected clinical and procedural data on 77 patients who underwent coronary angiography because of stable angina pectoris. Patients were randomized to the following device: FemoStop (mechanical compression), AngioSeal (anchor and collagen sponge), or Perclose (nonabsorbable suture). No patient group experienced an increased incidence of vascular complications. There were no differences among the three groups regarding CRP, fibrinogen, or IL-6 values before or after coronary angiography. IL-6 levels increased 6 h after the procedure in all groups (p < 0.01), however, the increase did not differ among the groups. After 30 days there were no increased values of CRP or fibrinogen. We conclude that the femoral arterial closure devices AngioSeal and Perclose do not enhance an inflammatory response after a diagnostic coronary angiography, measured by CRP, fibrinogen, and IL-6, compared to femoral arterial closure using a mechanical compression device.

  2. Titanium plate artefact mimicking popliteal artery dissection on digital subtraction CT angiography.

    PubMed

    Woodacre, Timothy; Wienand-Barnett, Sophie

    2013-04-05

    Titanium plates used for the internal fixation of long bone fractures cause significant artefact on CT scans but have not been reported to affect digital subtraction CT angiography. We present a patient with clinical suspicion of popliteal artery injury following a high tibial osteotomy. The osteotomy was stabilised with a titanium locking plate. During the digital subtraction process used to produce reconstruction CT angiography, removal of artefact caused by the titanium plate produced CT images mimicking the appearance of a popliteal artery dissection. The imaging inaccuracy was realised prior to the patient undergoing further intervention. We highlight the potential error caused by titanium plates on digital subtraction CT angiography and recommend careful analysis of such images prior to further treatment.

  3. Selection of patients for preoperative coronary angiography: use of dipyridamole-stress--thallium myocardial imaging

    SciTech Connect

    Brewster, D.C.; Okada, R.D.; Strauss, H.W.; Abbott, W.M.; Darling, R.C.; Boucher, C.A.

    1985-05-01

    To identify patients likely to benefit from preoperative coronary angiography, a method utilizing pharmacologically induced coronary vasodilatation in conjunction with serial thallium 201 myocardial perfusion imaging was investigated. Fifty-four patients admitted for elective aortic or femoropopliteal procedures were studied. There were no cardiac ischemic complications in 32 patients with normal scans or persistent defects (scar). In contrast, 7 of 15 patients with thallium redistribution (ischemia) on pre-operative scanning had perioperative ischemic events, including one death and two acute infarcts. An additional seven patients with positive scans (redistribution) underwent coronary angiography prior to vascular surgery; surgically important two- or three-vessel disease was confirmed in all. Dipyridamole-thallium imaging facilitates selection of the subset of truly high-risk patients in whom preoperative coronary angiography may be warranted.

  4. A rare case of coronary fistula evaluated by first-pass radionuclide angiography.

    PubMed

    Choi, Byung Wook; Kim, Hae Won; Won, Kyoung Sook; Song, Bong Il

    2016-01-01

    Coronary artery fistula (CAF) is a rare anomaly that originates from the coronary artery and drains into the cardiac chamber or the adjacent vasculature. We report a case of CAF in a 77 years old woman with dyspnea on exertion. Using coronary angiography and cardiac multidetector computed tomography, this patient was diagnosed with CAF draining into the left bronchial arteries. First-pass radionuclide angiography (FPRNA) showed early pulmonary recirculation through a left to right shunt. The pulmonary to systemic blood flow ratio was 1.24. The patient received supportive care with vasodilator and antiplatelet therapy. First-pass radionuclide angiography was used to provide physiologic informations, to plan the treatment course for this patient. PMID:27331213

  5. [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.

  6. Feasibility of Three-Dimensional MR Angiography Image Fusion Guidance for Endovascular Abdominal Aortic Aneurysm Repair.

    PubMed

    Tacher, Vania; Desgranges, Pascal; You, Ketsakin; Ridouani, Fourat; Marzelle, Jean; Kobeiter, Hicham

    2016-02-01

    Magnetic resonance (MR) angiography image fusion (IF) with live fluoroscopy guidance was used while performing endovascular repair of abdominal aortic aneurysm (EVAR) in five patients with a history of chronic renal disease or severe contrast allergy. Intraprocedural technical success was 100%. Median procedure time was 120 minutes (range, 60-180 min), fluoroscopy time was 40 minutes (range, 17-65 min), dose-area product was 245,867 mGy × cm(2) (range, 68,435-690,053 mGy × cm(2)), and iodinated contrast volume injected was 15 mL (range, 0-40 mL). Technical success was achieved in four of five patients (80%); one case was complicated by a type 1 endoleak on follow-up MR angiography, which was successfully treated. EVAR with MR angiography IF guidance was technically feasible and safe in five patients and reduced or eliminated the use of iodinated contrast media. PMID:26830935

  7. 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.

  8. An attempt at coronary angiography with a large size monochromatic SR beam

    NASA Astrophysics Data System (ADS)

    Akisada, A.; Ando, M.; Hyodo, K.; Hasegawa, S.; Konoshi, K.; Nishimura, K.; Maruhashi, A.; Toyofuku, F.; Suwa, A.; Kohra, K.

    1986-05-01

    The number of patients due to ischemic heart disease seems to be growing rapidly in Japan. Coronary angiography by Judkins' or Soncs' method is very invasive as is well known and thus imposes a burden on patients and physicians. The K-edge subtraction technique is considered to be applicable to intravenous angiography of coronary arteries. A feasibility study of K-edge subtraction with monochromatized SR has been initiated at Photon Factory since 1984. In 1985, a real time observation of intravenous angiography of a cat, utilizing a monochromatic beam with a size of 64 mm by 55 mm, was performed. This paper describes some results of our preliminary experiments and our future systems of clinical application.

  9. Associations of increases in serum creatinine with mortality and length of hospital stay after coronary angiography.

    PubMed

    Weisbord, Steven D; Chen, Huanyu; Stone, Roslyn A; Kip, Kevin E; Fine, Michael J; Saul, Melissa I; Palevsky, Paul M

    2006-10-01

    The absence of a universally accepted definition of radiocontrast nephropathy (RCN) has hampered efforts to characterize effectively the incidence and the clinical significance of this condition. The objective of this study was to identify a clinically relevant definition of RCN by assessment of the relationships between increases in serum creatinine (Scr) of varying magnitude after coronary angiography and clinical outcomes. An electronic medical database was used to identify all patients who underwent coronary angiography at the University of Pittsburgh Medical Center during a 12-yr period and abstract Scr levels before and after angiography, as well as demographic characteristics and comorbid conditions. Changes in Scr after angiography were categorized into mutually exclusive categories on the basis of absolute and relative changes from baseline levels, with a separate category denoting "unknown" change. Discrete proportional odds models were used to examine the association between increases in Scr and 30-d in-hospital mortality and length of stay. A total of 27,608 patients who underwent coronary angiography were evaluated. Small absolute (0.25 to 0.5 mg/dl) and relative (25 to 50%) increases in Scr were associated with risk-adjusted odds ratios for in-hospital mortality of 1.83 and 1.39, respectively. Larger increases in Scr generally were associated with greater risks for these clinical outcomes. Small increases in Scr after the administration of intravascular radiocontrast are associated with adverse patient outcomes. This observation will help guide the post-procedure care of patients who undergo coronary angiography and has important implications for future studies that investigate RCN.

  10. Complications of cerebral angiography in patients with symptomatic carotid territory ischaemia screened by carotid ultrasound.

    PubMed Central

    Davies, K N; Humphrey, P R

    1993-01-01

    After nearly 40 years, carotid endarterectomy has been shown to be of benefit to patients with symptomatic carotid territory ischaemia and greater than 70% stenosis of the relevant internal carotid artery. Cerebral angiography is performed before surgery and is not without risk. These risks must be added to those of surgery before recommending the procedure to patients. The study evaluated the local, systemic and neurological complications following digital subtraction angiography with selective catheterisation of the carotid arteries in 200 patients presenting to a cerebrovascular clinic for assessment of cerebral ischaemia. All patients had carotid ultrasound screening before angiography to screen out those with normal arteries or mild disease (less than 30% stenosis of symptomatic internal carotid artery). Complications occurred in 28 patients. There were six (3%) local, two (1%) systemic and 20 (10%) neurological complications. Seventeen neurological complications occurred within 24 hours and there were three late complications (24-72 hours). Neurological complications occurred more frequently when angiography was performed by a trainee rather than a consultant neuroradiologist (p < 0.01). The neurological complications were transient (resolved within 24 hours) in 10/200 (5%), reversible (resolved within seven days) in two (1%) and permanent in 8/200 (4%). Two patients died after a stroke and two other patients suffered a disabling stroke. At 24 hours post angiography the permanent (persisting beyond seven days) neurological complication rate was 2.5%. The incidence of total neurological complications and post angiographic strokes was higher in patients with greater than 90% stenosis of the symptomatic internal carotid artery (p < 0.001). The increased use of non-invasive Doppler duplex screening will reduced the absolute number of patients put at risk of angiography, yet the rate of post angiographic complications is likely to increase as patients with severe

  11. Coronary CT angiography: how should physicians use it wisely and when do physicians request it appropriately?

    PubMed

    Sun, Zhonghua; Aziz, Yang Faridah Abdul; Ng, Kwan-Hoong

    2012-04-01

    Coronary CT angiography has been increasingly used in the diagnosis of coronary artery disease due to rapid technological developments, which are reflected in the improved spatial and temporal resolution of the images. High diagnostic accuracy has been achieved with 64- and more slice CT scanners and in selected patients, coronary CT angiography is regarded as a reliable alternative to invasive coronary angiography. Although the tremendous contributions of coronary CT angiography to cardiac imaging are acknowledged, appropriate use of cardiac CT as the first line technique by physicians has not been well established. Optimal selection of cardiac CT is essential to ensure acquisition of valuable diagnostic information and avoid unnecessary invasive procedures. This is of paramount importance since cardiac CT not only involves patient risk assessment, prediction of major cardiac events, but also impacts physician decision-making on patient management. Applications of CT in cardiac imaging include coronary artery calcium scoring for predicting the patient risk of developing major cardiac events, followed by coronary CT angiography which is commonly used to determine the diagnostic and prognostic accuracy in the coronary artery disease. This review presents an overview of the applications of CT in cardiac imaging in terms of coronary calcium scoring and coronary CT angiography. Judicious use of both cardiac CT tools will be discussed with regard to their value in different patient risk groups with the aim of identifying the appropriate criteria for choosing a cardiac CT modality. An effective diagnostic pathway is finally recommended to physicians for appropriate selection of cardiac CT in clinical practice.

  12. 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

  13. 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

  14. 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

  15. OCT angiography in the management of choroidal neovascular membrane secondary to Sorsby fundus dystrophy.

    PubMed

    Mohla, Aditi; Khan, Kamron; Kasilian, Melissa; Michaelides, Michel

    2016-01-01

    We describe the management of a woman aged 52 years with molecularly confirmed Sorsby fundus dystrophy, who presented with acute visual deterioration in her right eye. Fundus examination identified a right macular lesion suggestive of a choroidal neovascular membrane (CNVM). Optical coherence tomography angiography (OCTA) confirmed the presence of a CNVM. She was treated with 2 monthly intravitreal injections of bevacizumab, associated with OCTA evidence of regression of the CNVM and improvement in her visual acuity. OCTA is a novel, non-invasive method of imaging the retinal vasculature. Images are acquired rapidly, with no associated side effects, offering advantages over the current gold standard technique-fundus fluorescein angiography. PMID:27587748

  16. Ultra-widefield fluorescein angiography reveals retinal phlebitis in Susac's syndrome.

    PubMed

    Klufas, Michael A; Dinkin, Marc J; Bhaleeya, Swetangi D; Chapman, Kristin O; Riley, Claire S; Kiss, Szilárd

    2014-01-01

    A 23-year-old woman with history of headaches and auditory changes presented with acute-onset visual field loss in the right eye. The combination of multiple retinal branch artery occlusions of the right eye on funduscopic examination, characteristic white matter lesions in the corpus callosum on magnetic resonance imaging, and hearing loss on audiometric testing led to a diagnosis of Susac's syndrome. Ultra-widefield fluorescein angiography revealed involvement of the retinal veins, which has not been previously reported with this condition. Additionally, ultra-widefield indocyanine green angiography demonstrated changes in the choroidal circulation, which are controversial in this syndrome. PMID:24972181

  17. OCT angiography in the management of choroidal neovascular membrane secondary to Sorsby fundus dystrophy

    PubMed Central

    Mohla, Aditi; Khan, Kamron; Kasilian, Melissa; Michaelides, Michel

    2016-01-01

    We describe the management of a woman aged 52 years with molecularly confirmed Sorsby fundus dystrophy, who presented with acute visual deterioration in her right eye. Fundus examination identified a right macular lesion suggestive of a choroidal neovascular membrane (CNVM). Optical coherence tomography angiography (OCTA) confirmed the presence of a CNVM. She was treated with 2 monthly intravitreal injections of bevacizumab, associated with OCTA evidence of regression of the CNVM and improvement in her visual acuity. OCTA is a novel, non-invasive method of imaging the retinal vasculature. Images are acquired rapidly, with no associated side effects, offering advantages over the current gold standard technique—fundus fluorescein angiography. PMID:27587748

  18. Quantitative optical coherence tomography angiography of choroidal neovascularization in age-related macular degeneration

    PubMed Central

    Jia, Yali; Bailey, Steven T.; Wilson, David J.; Tan, Ou; Klein, Michael L.; Flaxel, Christina J.; Potsaid, Benjamin; Liu, Jonathan J.; Lu, Chen D.; Kraus, Martin F.; Fujimoto, James G.; Huang, David

    2014-01-01

    Purpose To detect and quantify choroidal neovascularization (CNV) in age-related macular degeneration (AMD) patients using optical coherence tomography (OCT) angiography. Design Observational, cross-sectional study. Participants Five normal subjects and five neovascular AMD patients were included. Methods Five eyes with neovascular AMD and five normal age-matched controls were scanned by a high-speed (100,000 A-scans/sec) 1050 nm wavelength swept-source OCT. The macular angiography scan covered a 3×3 mm area and comprised 200×200×8 A-scans acquired in 3.5 sec. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by three dimensional (3D) orthogonal registration and merging of 4 scans. The 3D angiography was segmented into 3 layers: inner retina (to show retinal vasculature), outer retina (to identify CNV), and choroid. En face maximum projection was used to obtain 2D angiograms from the 3 layers. CNV area and flow index were computed from the en face OCT angiogram of the outer retinal layer. Flow (decorrelation) and structural data were combined in composite color angiograms for both en face and cross-sectional views. Main Outcome Measurements CNV angiogram, CNV area, and CNV flow index. Results En face OCT angiograms of CNVs showed sizes and locations that were confirmed by fluorescein angiography. OCT angiography provided more distinct vascular network patterns that were less obscured by subretinal hemorrhage. The en face angiograms also showed areas of reduced choroidal flow adjacent to the CNV in all cases and significantly reduced retinal flow in one case. Cross-sectional angiograms were used to visualize CNV location relative to the retinal pigment epithelium and Bruch’s layer and classify type I and type II CNV. A feeder vessel could be identified in one case. Higher flow indexes were associated with larger CNV and type II CNV. Conclusions OCT angiography provides depth

  19. 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.

  20. The safe practice of CT coronary angiography in adult patients in UK imaging departments.

    PubMed

    Harden, S P; Bull, R K; Bury, R W; Castellano, E A; Clayton, B; Hamilton, M C K; Morgan-Hughes, G J; O'Regan, D; Padley, S P G; Roditi, G H; Roobottom, C A; Stirrup, J; Nicol, E D

    2016-08-01

    Computed tomography coronary angiography is increasingly used in imaging departments in the investigation of patients with chest pain and suspected coronary artery disease. Due to the routine use of heart rate controlling medication and the potential for very high radiation doses during these scans, there is a need for guidance on best practice for departments performing this examination, so the patient can be assured of a good quality scan and outcome in a safe environment. This article is a summary of the document on 'Standards of practice of computed tomography coronary angiography (CTCA) in adult patients' published by the Royal College of Radiologists (RCR) in December 2014.

  1. High spatial resolution time-resolved magnetic resonance angiography of lower extremity tumors at 3T: Comparison with computed tomography angiography.

    PubMed

    Wu, Gang; Jin, Teng; Li, Ting; Morelli, John; Li, Xiaoming

    2016-09-01

    The aim of this study was to compare diagnostic value of high spatial resolution time-resolved magnetic resonance angiography with interleaved stochastic trajectory (TWIST) using Gadobutrol to Computed tomography angiography (CTA) for preoperative evaluation of lower extremity tumors.This prospective study was approved by the institutional review board. Fifty consecutive patients (31 men, 19 women, age range 18-80 years, average age 42.7 years) with lower extremity tumors underwent TWIST magnetic resonance angiography (MRA) and CTA. Digital subtraction angiography was available for 8 patients. Image quality of MRA was compared with CTA by 2 radiologists according to a 4-point Likert scale. Arterial involvement by tumor was compared using kappa test between MRA and CTA. The ability to identify feeding arteries and arterio-venous fistulae (AVF) was compared using Wilcoxon signed rank test and McNemar test, respectively.Image quality of MRA and CTA was rated without a statistically significant difference (3.88 ± 0.37 vs. 3.97 ± 0.16, P = 0.135). Intramodality agreement was high for the identification of arterial invasion (kappa = 0.806 ± 0.073 for Reader 1, kappa = 0.805 ± 0.073 for Reader 2). Readers found AVF in 27 of 50 MRA cases and 14 of 50 CTA cases (P < 0.001). Mean feeding arteries identified with MRA were significantly more than that with CTA (2.08 ± 1.72 vs. 1.62 ± 1.52, P = .02).TWIST MRA is a reliable imaging modality for the assessment of lower extremity tumors. TWIST MRA is comparable to CTA for the identification of AVF and feeding arteries. PMID:27631262

  2. Dual Energy CT Angiography of Peripheral Arterial Disease: Feasibility of Using Lower Contrast Medium Volume

    PubMed Central

    Almutairi, Abdulrahman; Sun, Zhonghua; Poovathumkadavi, Abduljaleel; Assar, Tarek

    2015-01-01

    Objective One of the main drawbacks associated with Dual Energy Computed Tomography Angiography (DECTA) is the risk of developing contrast medium-induced nephropathy (CIN). The aim of the present study was firstly, to design an optimal CT imaging protocol by determining the feasibility of using a reduced contrast medium volume in peripheral arterial DECTA, and secondly, to compare the results with those obtained from using routine contrast medium volume. Methods Thirty four patients underwent DECTA for the diagnosis of peripheral arterial disease. They were randomly divided into two groups: Group 1 (routine contrast volume group) with n = 17, injection rate 4–5 ml/s, and 1.5 ml/kg of contrast medium, and Group 2 ((low contrast volume group), with n = 17, injection rate 4–5ml/s, and contrast medium volume 0.75 ml/kg. A fast kilovoltage—switching 64-slice CT scanner in the dual-energy mode was employed for the study. A total of 6 datasets of monochromatic images at 50, 55, 60, 65, 70 and 75 keV levels were reconstructed with adaptive statistical iterative reconstruction (ASIR) at 50%. A 4-point scale was the tool for qualitative analysis of results. The two groups were compared and assessed quantitatively for image quality on the basis of signal-to-noise ratio (SNR) and contrast-to-noise-ratio (CNR). Radiation and contrast medium doses were also compared. Results The overall mean CT attenuation and mean noise for all lower extremity body parts was significantly lower for the low volume contrast group (p<0.001), and varied significantly between groups (p = 0.001), body parts (p<0.001) and keVs (p<0.001). The interaction between group body parts was significant with CT attenuation and CNR (p = 0.002 and 0.003 respectively), and marginally significant with SNR (p = 0.047), with minimal changes noticed between the two groups. Group 2 (low contrast volume group) displayed the lowest image noise between 65 and 70 keV, recorded the highest SNR and CNR at 65 keV, and

  3. Random broadcast on random geometric graphs

    SciTech Connect

    Bradonjic, Milan; Elsasser, Robert; Friedrich, Tobias

    2009-01-01

    In this work, we consider the random broadcast time on random geometric graphs (RGGs). The classic random broadcast model, also known as push algorithm, is defined as: starting with one informed node, in each succeeding round every informed node chooses one of its neighbors uniformly at random and informs it. We consider the random broadcast time on RGGs, when with high probability: (i) RGG is connected, (ii) when there exists the giant component in RGG. We show that the random broadcast time is bounded by {Omicron}({radical} n + diam(component)), where diam(component) is a diameter of the entire graph, or the giant component, for the regimes (i), or (ii), respectively. In other words, for both regimes, we derive the broadcast time to be {Theta}(diam(G)), which is asymptotically optimal.

  4. Grading of Age-Related Macular Degeneration: Comparison between Color Fundus Photography, Fluorescein Angiography, and Spectral Domain Optical Coherence Tomography

    PubMed Central

    Mokwa, Nils F.; Keane, Pearse A.; Kirchhof, Bernd; Sadda, Srinivas R.

    2013-01-01

    Purpose. To compare color fundus photography (FP), fluorescein angiography (FA), and spectral domain optical coherence tomography (SDOCT) for the detection of age-related macular degeneration (AMD), choroidal neovascularisation (CNV), and CNV activity. Methods. FPs, FAs, and SDOCT volume scans from 120 eyes of 66 AMD and control patients were randomly collected. Control eyes were required to show no AMD, but other retinal pathology was allowed. The presence of drusen, pigmentary changes, CNV, and signs for CNV activity was independently analyzed for all imaging modalities. Results. AMD was diagnosed based on FP in 75 eyes. SDOCT and FA showed sensitivity (specificity) of 89% (76%) and 92% (82%), respectively. CNV was present on FA in 68 eyes. Sensitivity (specificity) was 78% (100%) for FP and 94% (98%) for SDOCT. CNV activity was detected by SDOCT or FA in 60 eyes with an agreement in 46 eyes. Sensitivity was 88% for SDOCT and 88% for FA. FP showed sensitivity of 38% and specificity of 98%. Conclusions. CNV lesions and activity may be missed by FP alone, but FP may help identifying drusen and pigmentary changes. SDOCT is highly sensitive for the detection of AMD, CNV, and CNV activity; however, it cannot fully replace FA. PMID:23762528

  5. Quantumness, Randomness and Computability

    NASA Astrophysics Data System (ADS)

    Solis, Aldo; Hirsch, Jorge G.

    2015-06-01

    Randomness plays a central role in the quantum mechanical description of our interactions. We review the relationship between the violation of Bell inequalities, non signaling and randomness. We discuss the challenge in defining a random string, and show that algorithmic information theory provides a necessary condition for randomness using Borel normality. We close with a view on incomputablity and its implications in physics.

  6. Surgical treatment of distal anterior cerebral artery aneurysms aided by electromagnetic navigation CT angiography.

    PubMed

    Hermann, Elvis J; Petrakakis, Ioannis; Götz, Friedrich; Lütjens, Götz; Lang, Josef; Nakamura, Makoto; Krauss, Joachim K

    2015-07-01

    The surgical treatment of distal anterior cerebral artery (DACA) aneurysms still presents a challenge for neurosurgeons because of their small size and their location in the depth of the narrow frontal interhemispheric fissure. This study aimed to investigate feasibility, safety, accuracy, and usefulness of electromagnetic (EM) navigation to aid clipping of DACA aneurysms. Eight patients (age between 2 and 68 years, mean age 49.8 years) with a DACA aneurysm underwent EM-guided neuronavigated microsurgery for clipping of the aneurysm. All patients underwent craniocervical 3D-CT angiography preoperatively. After planning the optimal approach and surgical trajectory avoiding opening of the frontal sinus, the head was fixed. Intraoperative screenshots were correlated with the microscopical view of the DACA aneurysms before clipping. EM-guided neuronavigation using CT angiography for DACA aneurysms enabled fast and accurate referencing of the patient and planning of a tailored craniotomy without opening of the frontal sinus. Intraoperative accuracy was highly reliable except in one instance due to dislocation of the dynamic reference frame (DRF). There was a good correlation between the 3D-CT angiography-based navigation data sets and the intraoperative vascular anatomy. In all patients, bridging veins were spared. The aid of EM neuronavigation was considered useful in all instances. EM-guided neuronavigation using CT angiography for surgery of DACA aneurysms is a useful tool optimizing the surgical approach directly to the aneurysm minimizing additional damage to the surrounding tissue during preparation of the aneurysm and the parent vessel. PMID:25666391

  7. Percutaneous trans-ulnar artery approach for coronary angiography and angioplasty; A case series study

    PubMed Central

    Roghani-Dehkordi, Farshad; Hadizadeh, Mahmood; Hadizadeh, Fatemeh

    2015-01-01

    BACKGROUND Coronary angiography is the gold standard method for diagnosis of coronary heart disease and usually performed by femoral approach that has several complications. To reduce these complications, upper extremity approach is increasingly used and is becoming preferred access site by many interventionists. Although radial approach is relatively well studied, safety, feasibility and risk of applying ulnar approach in not clearly known yet. METHODS We followed 97 patients (man = 56%, mean ± standard deviation of age = 57 ± 18) who had undergone coronary angiography or angioplasty via ulnar approach for 6-10 months and recorded their outcomes. RESULTS In 97 patients out of 105 ones (92.38%), procedure through ulnar access were successfully done. Unsuccessful puncture (3 patients), wiring (2 patients), passing of sheet (2 patients), and anatomically unsuitable ulnar artery (1 patient) were the reasons of failure. In 94 patients (89.52%), the angiography and angioplasty was done without any complications. Five patients (5.1%) hematoma and 11 patients (11%) experienced low-grade pain that resolved with painkiller. No infection, amputation or need for surgery was reported. CONCLUSION This study demonstrated that ulnar access in our patients was a safe and practical approach for coronary angiography or angioplasty, without any major complication. Bearing in mind its high success rate, it can be utilized when a radial artery is not useful for the catheterization and in cases such as prior harvesting of the radial artery (in prior coronary artery bypass grafting). PMID:26715936

  8. 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.

  9. Anterior Segment Scleral Fluorescein Angiography in the Evaluation of Ciliary Body Neoplasm: Two Case Reports

    PubMed Central

    Marvasti, Amir H.; Berry, Jesse; Sibug, Maria E. Saber; Kim, Jonathan W.; Huang, Alex S.

    2016-01-01

    Introduction Anterior segment tumors can be difficult to detect until tumor growth is substantial enough to cause local signs or symptoms. Earlier detection may result in improved outcomes, particularly the ability to option for globe-conserving therapy. Multiple diagnostic modalities such as ultrasound or optical coherence tomography exist to aid for earlier detection of ciliary body tumors, but they also have limitations. Here we describe the potential for scleral angiography as an adjunctive modality to assist in evaluating anterior segment ciliary body tumors. Case Presentations A 61-year-old Caucasian male and a 57-year-old Hispanic female presented for ciliary body tumor evaluation. The Caucasian male notably had abnormal scleral, episcleral, and conjunctival vessels in the affected eye. Scleral angiography was performed in both cases with the abnormal vasculature highlighted in the Caucasian male. The Hispanic female did not demonstrate abnormal scleral angiographic patterns. Notably, the Caucasian male also had regions of abnormal scleral angiography arising in locations of otherwise normal appearing sclera. Both patients had the affected eyes enucleated. Histology of the enucleated eyes demonstrated a ciliary body melanoma in the Caucasian male associated with abnormal vascular and tumor infiltration of the scleral bed. The Hispanic female had a pigmented ciliary body adenoma without involvement of the scleral bed. Conclusion With limited sample size, scleral angiography has the potential to detect abnormal scleral vascular patterns in otherwise normal appearing sclera in cases of ciliary body tumor with scleral vascular invasion. PMID:26889157

  10. Optical Coherence Tomography Angiography in Retinal Vascular Diseases and Choroidal Neovascularization

    PubMed Central

    Mastropasqua, Rodolfo; Di Antonio, Luca; Di Staso, Silvio; Agnifili, Luca; Di Gregorio, Angela; Ciancaglini, Marco; Mastropasqua, Leonardo

    2015-01-01

    Purpose. To assess the ability of optical coherence tomography-angiography (OCT-A) to show and analyze retinal vascular patterns and the choroidal neovascularization (CNV) in retinal vascular diseases. Methods. Seven eyes of seven consecutive patients with retinal vascular diseases were examined. Two healthy subjects served as controls. All eyes were scanned with the SD-OCT XR Avanti (Optovue Inc, Fremont CA, USA). Split spectrum amplitude decorrelation angiography algorithm was used to identify the blood flow within the tissue. Fluorescein angiography (FA) and indocyanine green angiography (ICGA) with Spectralis HRA + OCT (Heidelberg Engineering GmbH) were performed. Results. In healthy subjects OCT-A visualized major macular vessels and detailed capillary networks around the foveal avascular zone. Patients were affected with myopic CNV (2 eyes), age-related macular degeneration related (2), branch retinal vein occlusion (BRVO) (2), and branch retinal artery occlusion (BRAO) (1). OCT-A images provided distinct vascular patterns, distinguishing perfused and nonperfused areas in BRVO and BRAO and recognizing the presence, location, and size of CNV. Conclusions. OCT-A provides detailed images of retinal vascular plexuses and quantitative data of pathologic structures. Further studies are warranted to define the role of OCT-A in the assessment of retinovascular diseases, with respect to conventional FA and ICG-A. PMID:26491548

  11. Coronary artery WSS profiling using a geometry reconstruction based on biplane angiography.

    PubMed

    Goubergrits, Leonid; Wellnhofer, Ernst; Kertzscher, Ulrich; Affeld, Klaus; Petz, Christoph; Hege, Hans-Christian

    2009-04-01

    Computational fluid dynamics (CFD) methods based on three-dimensional (3D) vessel reconstructions have recently been shown to provide prognostically relevant hemodynamic data. However, the geometry reconstruction and the assessment of clinically relevant hemodynamic parameters may depend on the used imaging modality. In this study, the silicon model of the left coronary artery (LCA) was acquired with a biplane angiography. The geometry reconstruction was done using commercial CAAS 5.2 QCA 3D software and compared with an original geometry. The original model is an optically digitized post-mortem vessel cast. The biplane angiography reconstruction achieved a Hausdorff surface distance of 0.236 mm to the original geometry that is comparable with results obtained in our earlier study for computed tomography (CT) and magnetic resonance imaging (MRI) reconstructions. Steady flow simulations were performed with a commercial CFD program FLUENT. A comparison of the calculated wall shear stress (WSS) shows good correlation for histograms (r=0.97) and good agreement among the four modalities with a mean WSS of 0.65 Pa in the original model, of 0.68 Pa in the CT-based model, of 0.67 Pa in the MRI based model, and of 0.69 Pa in the biplane angiography-based model. We can conclude that the biplane angiography-based reconstructions can be used for the WSS profiling of the coronary arteries.

  12. Indocyanine Green Near-Infrared Laser Angiography Predicts Timing for the Division of a Forehead Flap

    PubMed Central

    Christensen, Joani M.; Baumann, Donald P.; Myers, Jeffrey N.; Buretta, Kate; Sacks, Justin M.

    2012-01-01

    Introduction: Reconstruction with flaps requiring delayed division remains common, even with increasing use of free tissue transfer. Patient quality of life and function are significantly decreased during the delay period. Delay could be minimized by developing methods to reliably determine when the flap has developed sufficient vascular supply to undergo successful division. We report the use of laser angiography to determine the appropriate time for division of a forehead flap pedicle. Methods: The patient who had risk factors for microvascular disease underwent near-infrared laser angiography using indocyanine green on postoperative day 21 to assess vascular perfusion of the flap. Although traditional clinical examination indicated the flap was not adequately perfused, laser angiography revealed perfusion to all areas of the flap, so the pedicle was divided. Results: Pedicle division was successful, with no epidermolysis or necrosis. Conclusion: Near-infrared laser angiography with indocyanine green can assess perfusion status of the entire flap and inform the decision to divide the flap in an objective manner. PMID:22977676

  13. 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.

  14. Non-contrast-enhanced Peripheral Angiography Using a Sliding Interleaved Cylinder Acquisition

    PubMed Central

    Kwon, Kie Tae; Kerr, Adam B.; Wu, Holden H.; Hu, Bob S.; Brittain, Jean H.; Nishimura, Dwight G.

    2014-01-01

    Purpose To develop a new sequence for non-contrast-enhanced peripheral angiography using a sliding interleaved cylinder (SLINCYL) acquisition. Methods A venous saturation pulse was incorporated into a 3D magnetization-prepared balanced steady-state free precession sequence for non-contrast-enhanced peripheral angiography to improve artery-vein contrast. The SLINCYL acquisition, which consists of a series of overlapped thin slabs for volumetric coverage similar to the original sliding interleaved ky (SLINKY) acquisition, was employed to evenly distribute the venous-suppression effects over the FOV. In addition, the thin-slab-scan nature of SLINCYL and the centric-ordered sampling geometry of its readout trajectory were exploited to implement efficient fluid-suppression and parallel imaging approaches. The sequence was tested in healthy subjects and a patient. Results Compared to a multiple overlapped thin slab acquisition, both SLINKY and SLINCYL suppressed the venetian blind artifacts and provided similar artery-vein contrast. However, SLINCYL achieved this with shorter scan times and less noticeable artifacts from k-space amplitude modulation than SLINKY. The fluid-suppression and parallel imaging schemes were also validated. A patient study using the SLINCYL-based sequence well identified stenoses at the super cial femoral arteries, which were also confirmed with digital subtraction angiography. Conclusion Non-contrast-enhanced angiography using SLINCYL can provide angiograms with improved artery-vein contrast in the lower extremities. PMID:25203505

  15. 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

  16. 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.

  17. Early Swept-Source Optical Coherence Tomography Angiography Findings in Unilateral Acute Idiopathic Maculopathy.

    PubMed

    Nicolo, Massimo; Rosa, Raffaella; Musetti, Donatella; Musolino, Maria; Traverso, Carlo Enrico

    2016-02-01

    Unilateral acute idiopathic maculopathy (UAIM) is a rare disorder presenting in young people with an acute onset of unilateral central visual loss often associated with a prodromal flu-like illness. The authors present the early anatomical findings of a 35-year-old man clinically diagnosed with UAIM using swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography.

  18. [Development of a prevention of body movement fixation appliance in leg digital subtraction angiography].

    PubMed

    Yasuda, Mitsuyoshi; Kato, Kyouichi; Sakiyama, Koushi; Uchiyama, Yushi; Asanuma, Shinichi; Fujimura, Kazumasa; Suzuki, Hiroshi; Nakazawa, Yasuo

    2010-01-20

    In the peripheral angiography to evaluate blood flow below the knee levels in patients with arteriosclerosis obliterans, a motion artifact occurs as a result of body movements of a patient in normal fixation. This sometimes makes a correct evaluation difficult. Therefore, we developed a fixed appliance which can restrain body movement without affecting image quality and blood flow in digital subtraction angiography of a leg. The appliance is filled with the styrofoam of 1 mm diameter in a sealed bag, after air is aspirated from inside the bag. The appliance is stiffened to fit the shape of the crus. We measured signal to noise ratio / contrast to noise ratio / a resolution limit by visual evaluation to examine the influence of the image before and after usage of this appliance. In addition, the blood velocity of the dorsalis artery in ultrasound was measured to examine the effect on the blood flow. As a result, the fixed appliance did not affect blood flow in peripheral angiography to evaluate the clinical significance, the usual 5-point evaluate scale was used. The scale was significantly improved (p <0.01) after usage of this appliance. The newly developed fixed appliance for digital subtraction angiography of a leg is useful to avoid motion artifacts in clinical settings. PMID:20145364

  19. The importance of angiography in tumours of the head and neck.

    PubMed

    Coyas, A; Tzagarakis, M; Giorgis, G; Katsiotis, P

    1980-04-01

    Reference is made to five cases appearing as expansive lesions in the head and neck. In all cases angiography allowed a precise diagnosis of the nature and extent of the lesion. Biopsy which could have been hazardous was thus unnecessary. Moreover, therapeutic embolization in a case of juvenile nasopharyngeal angiofibroma prevented massive bleeding during surgery.

  20. Detection of a traumatic renal aterial venous fistula by radionuclide angiography (RNA)

    SciTech Connect

    Sequeira, J.C.; Weitzman, A.F.; Lee, V.W.; Grosso, D.L.

    1981-01-01

    A case of post-traumatic A-V fistula was detected by radionuclide angiography. A 40-yr-old male, with a stab wound in left upper quadrant of abdomen, had undergone exploratory laparotomy that disclosed lacerations of the stomach and proximal portions of small bowel and superior mesenteric artery. The patient continued to have quaiac-positive stools postoperatively. One week later a radionuclide sequential image of the abdomen using 8 mCi of Tc-99m sulfur colloid revealed an area of increased radionuclide concentration in the left midabdomen seen only during aterial phase and not visible on the subsequent static images. The findings were confirmed to be A-V fistula by angiogram and subsequently by renal surgery. The patient had an uneventful elective closure of the fistula. The cause of quaiac-positive stool was unexplained. Eight cases of renal A-V fistula have been well demonstrated by radionuclide angiography in the literature. The authors emphasized the radionuclide angiography is a suitable screening procedure for patients with suspected traumatic vascular injury, and contrast angiography should be used for the confirmation of diagnosis.

  1. [OCT angiography for exudative age-related macular degeneration : Initial experiences].

    PubMed

    Lommatzsch, A; Farecki, M-L; Book, B; Heimes, B; Pauleikhoff, D

    2016-01-01

    The new technique of optical coherence tomography (OCT) angiography allows a non-invasive reconstruction of the three-dimensional structure of the total retinal and choroidal vascularization within seconds. There are still limitations caused by movement artefacts, superimposition of superficial retinal vessels at the retinal pigment epithelium (RPE) level and insufficient three-dimensional imaging modalities. Initial experiences with this new method and especially the correlation with the current standard diagnostic procedure of fluorescein angiography show that new information can be obtained regarding specific vascular and neovascular changes. For three-dimensional neovascular changes, such as those found in exudative age-related macular degeneration (AMD,) a more sophisticated diagnostic analysis strategy must be specifically developed. Initial experiences demonstrate that the differentiation into the various types of choroidal neovascularization (CNV) by fluorescein angiography, specifically for type 1 (occult) and type 2 (classical) can also be visualized by OCT angiography. Furthermore, the new technology provides additional information on the choroidal and outer retinal changes associated with this disease, which may result in a better understanding of the underlying pathology. PMID:26743785

  2. Use of Coronary Computed Tomographic Angiography Findings to Modify Statin and Aspirin Prescription in Patients With Acute Chest Pain.

    PubMed

    Pursnani, Amit; Celeng, Csilla; Schlett, Christopher L; Mayrhofer, Thomas; Zakroysky, Pearl; Lee, Hang; Ferencik, Maros; Fleg, Jerome L; Bamberg, Fabian; Wiviott, Stephen D; Truong, Quynh A; Udelson, James E; Nagurney, John T; Hoffmann, Udo

    2016-02-01

    Coronary CT angiography (CCTA) is used in patients with low-intermediate chest pain presenting to the emergency department for its reliability in excluding acute coronary syndrome (ACS). However, its influence on medication modification in this setting is unclear. We sought to determine whether knowledge of CCTA-based coronary artery disease (CAD) was associated with change in statin and aspirin prescription. We used the CCTA arm of the Rule Out Myocardial Infarction using Computed Angiographic Tomography II multicenter, randomized control trial (R-II) and comparison cohort from the observational Rule Out Myocardial Infarction using Computed Angiographic Tomography I cohort (R-I). In R-II, subjects were randomly assigned to CCTA to guide decision making, whereas in R-I patients underwent CCTA with results blinded to caregivers and managed according to standard care. Our final cohort consisted of 277 subjects from R-I and 370 from R-II. ACS rate was similar (6.9% vs 6.2% respectively, p = 0.75). For subjects with CCTA-detected obstructive CAD without ACS, initiation of statin was significantly greater after disclosure of CCTA results (0% in R-I vs 20% in R-II, p = 0.009). Conversely, for subjects without CCTA-detected CAD, aspirin prescription was lower with disclosure of CCTA results (16% in R-I vs 4.8% in R-II, p = 0.001). However, only 68% of subjects in R-II with obstructive CAD were discharged on statin and 65% on aspirin. In conclusion, physician knowledge of CCTA results leads to improved alignment of aspirin and statin with the presence and severity of CAD although still many patients with CCTA-detected CAD are not discharged on aspirin or statin. Our findings suggest opportunity for practice improvement when CCTA is performed in the emergency department.

  3. Magnetic Resonance Angiography in the Diagnosis of Cerebral Arteriovenous Malformation and Dural Arteriovenous Fistulas: Comparison of Time-Resolved Magnetic Resonance Angiography and Three Dimensional Time-of-Flight Magnetic Resonance Angiography

    PubMed Central

    Cheng, Yu-Ching; Chen, Hung-Chieh; Wu, Chen-Hao; Wu, Yi-Ying; Sun, Ming-His; Chen, Wen-Hsien; Chai, Jyh-Wen; Chi-Chang Chen, Clayton

    2016-01-01

    Background Traditional digital subtraction angiography (DSA) is currently the gold standard diagnostic method for the diagnosis and evaluation of cerebral arteriovenous malformation (AVM) and dural arteriovenous fistulas (dAVF). Objectives The aim of this study was to analyze different less invasive magnetic resonance angiography (MRA) images, time-resolved MRA (TR-MRA) and three-dimensional time-of-flight MRA (3D TOF MRA) to identify their diagnostic accuracy and to determine which approach is most similar to DSA. Patients and Methods A total of 41 patients with AVM and dAVF at their initial evaluation or follow-up after treatment were recruited in this study. We applied time-resolved angiography using keyhole (4D-TRAK) MRA to perform TR-MRA and 3D TOF MRA examinations simultaneously followed by DSA, which was considered as a standard reference. Two experienced neuroradiologists reviewed the images to compare the diagnostic accuracy, arterial feeder and venous drainage between these two MRA images. Inter-observer agreement for different MRA images was assessed by Kappa coefficient and the differences of diagnostic accuracy between MRA images were evaluated by the Wilcoxon rank sum test. Results Almost all vascular lesions (92.68%) were correctly diagnosed using 4D-TRAK MRA. However, 3D TOF MRA only diagnosed 26 patients (63.41%) accurately. There were statistically significant differences regarding lesion diagnostic accuracy (P = 0.008) and venous drainage identification (P < 0.0001) between 4D-TRAK MRA and 3D TOF MRA. The results indicate that 4D-TRAK MRA is superior to 3D TOF MRA in the assessment of lesions. Conclusion Compared with 3D TOF MRA, 4D-TRAK MRA proved to be a more reliable screening modality and follow-up method for the diagnosis of cerebral AVM and dAVF.

  4. Magnetic Resonance Angiography in the Diagnosis of Cerebral Arteriovenous Malformation and Dural Arteriovenous Fistulas: Comparison of Time-Resolved Magnetic Resonance Angiography and Three Dimensional Time-of-Flight Magnetic Resonance Angiography

    PubMed Central

    Cheng, Yu-Ching; Chen, Hung-Chieh; Wu, Chen-Hao; Wu, Yi-Ying; Sun, Ming-His; Chen, Wen-Hsien; Chai, Jyh-Wen; Chi-Chang Chen, Clayton

    2016-01-01

    Background Traditional digital subtraction angiography (DSA) is currently the gold standard diagnostic method for the diagnosis and evaluation of cerebral arteriovenous malformation (AVM) and dural arteriovenous fistulas (dAVF). Objectives The aim of this study was to analyze different less invasive magnetic resonance angiography (MRA) images, time-resolved MRA (TR-MRA) and three-dimensional time-of-flight MRA (3D TOF MRA) to identify their diagnostic accuracy and to determine which approach is most similar to DSA. Patients and Methods A total of 41 patients with AVM and dAVF at their initial evaluation or follow-up after treatment were recruited in this study. We applied time-resolved angiography using keyhole (4D-TRAK) MRA to perform TR-MRA and 3D TOF MRA examinations simultaneously followed by DSA, which was considered as a standard reference. Two experienced neuroradiologists reviewed the images to compare the diagnostic accuracy, arterial feeder and venous drainage between these two MRA images. Inter-observer agreement for different MRA images was assessed by Kappa coefficient and the differences of diagnostic accuracy between MRA images were evaluated by the Wilcoxon rank sum test. Results Almost all vascular lesions (92.68%) were correctly diagnosed using 4D-TRAK MRA. However, 3D TOF MRA only diagnosed 26 patients (63.41%) accurately. There were statistically significant differences regarding lesion diagnostic accuracy (P = 0.008) and venous drainage identification (P < 0.0001) between 4D-TRAK MRA and 3D TOF MRA. The results indicate that 4D-TRAK MRA is superior to 3D TOF MRA in the assessment of lesions. Conclusion Compared with 3D TOF MRA, 4D-TRAK MRA proved to be a more reliable screening modality and follow-up method for the diagnosis of cerebral AVM and dAVF. PMID:27679690

  5. Directed random walk with random restarts: The Sisyphus random walk

    NASA Astrophysics Data System (ADS)

    Montero, Miquel; Villarroel, Javier

    2016-09-01

    In this paper we consider a particular version of the random walk with restarts: random reset events which suddenly bring the system to the starting value. We analyze its relevant statistical properties, like the transition probability, and show how an equilibrium state appears. Formulas for the first-passage time, high-water marks, and other extreme statistics are also derived; we consider counting problems naturally associated with the system. Finally we indicate feasible generalizations useful for interpreting different physical effects.

  6. 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.

  7. [Intraoperative verification of a perforator flap vascularization by indocyanine green angiography].

    PubMed

    Royer, E; Rausky, J; Binder, J-P; May, P; Virzi, D; Revol, M

    2014-02-01

    After Koshima and Soeda first described perforator flaps in 1988, Wei has improved the technique by describing the "free style perforator flap". These flaps have the advantage of being performed on all skin perforators and in reducing donor site morbidity. The disadvantage, however is that the size of their angiosome is not defined and the evaluation of their relay on the experience of the surgeon. An evaluation of the size of an angiosome by conducting intraoperative angiography is proposed. Intraoperative angiography is performed after injection of indocyanine green. Stimulation of the indocyanine green by infrared causes the emission of fluorescent radiation. This fluorescence is then detected by a specific camera that displays real-time visualization of the skin's perfusion. We present the case of a 39-year-old patient who had an open tibial pilon fracture, for which we performed a pedicled propeller flap based on a posterior tibial perforator. Angiography was used to determine accurately the optimal skin perfusion of the propeller flap, which was based on a perforator from the posterior tibial artery. Angiography identified several levels of skin perfusion with a high fluorescence, intermediate and absent. The non-vascularized part of the skin paddle was resected. Given the unreliability of this technique, hypoperfused area was retained. Debridment of this area, however was necessary at day 5 postoperative with repositionning of the flap. Indocyanine green angiography may be a useful decision-making tool for intraoperative surgeon. It allows to adjust the size of the propeller flap's skin paddle to it angiosome. However, this evaluation method needs to be improved with the introduction of a quantitative threshold.

  8. 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.

  9. [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.

  10. Prognostic capabilities of coronary computed tomographic angiography before non-cardiac surgery: prospective cohort study

    PubMed Central

    Chan, Matthew; Butler, Craig; Chow, Benjamin; Tandon, Vikas; Nagele, Peter; Mitha, Ayesha; Mrkobrada, Marko; Szczeklik, Wojciech; Faridah, Yang; Biccard, Bruce; Stewart, Lori K; Heels-Ansdell, Diane; Devereaux, P J

    2015-01-01

    Objectives To determine if coronary computed tomographic angiography enhances prediction of perioperative risk in patients before non-cardiac surgery and to assess the preoperative coronary anatomy in patients who experience a myocardial infarction after non-cardiac surgery. Design Prospective cohort study. Setting 12 centers in eight countries. Participants 955 patients with, or at risk of, atherosclerotic disease who underwent non-cardiac surgery. Interventions Coronary computed tomographic angiography was performed preoperatively; clinicians were blinded to the results unless left main disease was suspected. Results were classified as normal, non-obstructive (<50% stenosis), obstructive (one or two vessels with ≥50% stenosis), or extensive obstructive (≥50% stenosis in two vessels including the proximal left anterior descending artery, three vessels, or left main). Main outcome measure Composite of cardiovascular death and non-fatal myocardial infarction within 30 days after surgery (primary outcome). This was the dependent variable in Cox regression. The independent variables were scores on the revised cardiac risk index and findings on coronary computed tomographic angiography. Results The primary outcome occurred in 74 patients (8%). The model that included both scores on the revised cardiac risk index and findings on coronary computed tomographic angiography showed that coronary computed tomographic angiography provided independent prognostic information (P=0.014; C index=0.66). The adjusted hazard ratios were 1.51 (95% confidence interval 0.45 to 5.10) for non-obstructive disease; 2.05 (0.62 to 6.74) for obstructive disease; and 3.76 (1.12 to 12.62) for extensive obstructive disease. For the model with coronary computed tomographic angiography compared with the model based on the revised cardiac risk index alone, with 30 day risk categories of <5%, 5-15%, and >15% for the primary outcome, the results of risk reclassification indicate that in a sample of

  11. Intraarterial CT Angiography Using Ultra Low Volume of Iodine Contrast – Own Experiences

    PubMed Central

    Garcarek, Jerzy; Kurcz, Jacek; Guziński, Maciej; Banasik, Mirosław; Miś, Marcin; Gołębiowski, Tomasz

    2015-01-01

    Summary Background High volume of intravenous contrast in CT-angiography may result in contrast-induced nephropathy. Intraarterial ultra-low volume of contrast medium results in its satisfactory blood concentration with potentially good image quality. The first main purpose was to assess the influence of the method on function of transplanted kidney in patients with impaired graft function. The second main purpose of the study was to evaluate the usefulness of this method for detection of gastrointestinal and head-and-neck haemorrhages. Material/Methods Between 2010 and 2013 intraarterial CT-angiography was performed in 56 patients, including 28 with chronic kidney disease (CKD). There were three main subgroups: 18 patients after kidney transplantation, 10 patients with gastrointestinal hemorrhage, 8 patients with head-and-neck hemorrhage. Contralateral or ipsilateral inguinal arterial approach was performed. The 4-French vascular sheaths and 4F-catheters were introduced under fluoroscopy. Intraarterial CT was performed using 64-slice scanner. The scanning protocol was as follows: slice thickness 0.625 mm, pitch 1.3, gantry rotation 0.6 sec., scanning delay 1–2 sec. The extent of the study was established on the basis of scout image. In patients with CKD 6–8 mL of Iodixanol (320 mg/mL) diluted with saline to 18–24 mL was administered at a speed of 4–5 mL/s. Results Vasculature was properly visualized in all patients. In patients with impaired renal function creatinine/eGFR levels remained stable in all but one case. Traditional arteriography failed and CT-angiography demonstrated the site of bleeding in 3 of 10 patients with symptoms of gastrointestinal bleeding (30%). In 8 patients with head-and-neck bleeding CT-angiography did not prove beneficial when compared to traditional arteriography. Conclusions 1. Ultra-low contrast intraarterial CT-angiography does not deteriorate the function of transplanted kidneys in patients with impaired graft function. 2. 3

  12. Randomization in robot tasks

    NASA Technical Reports Server (NTRS)

    Erdmann, Michael

    1992-01-01

    This paper investigates the role of randomization in the solution of robot manipulation tasks. One example of randomization is shown by the strategy of shaking a bin holding a part in order to orient the part in a desired stable state with some high probability. Randomization can be useful for mobile robot navigation and as a means of guiding the design process.

  13. Random Item IRT Models

    ERIC Educational Resources Information Center

    De Boeck, Paul

    2008-01-01

    It is common practice in IRT to consider items as fixed and persons as random. Both, continuous and categorical person parameters are most often random variables, whereas for items only continuous parameters are used and they are commonly of the fixed type, although exceptions occur. It is shown in the present article that random item parameters…

  14. Quantum random number generation

    DOE PAGESBeta

    Ma, Xiongfeng; Yuan, Xiao; Cao, Zhu; Zhang, Zhen; Qi, Bing

    2016-06-28

    Here, quantum physics can be exploited to generate true random numbers, which play important roles in many applications, especially in cryptography. Genuine randomness from the measurement of a quantum system reveals the inherent nature of quantumness -- coherence, an important feature that differentiates quantum mechanics from classical physics. The generation of genuine randomness is generally considered impossible with only classical means. Based on the degree of trustworthiness on devices, quantum random number generators (QRNGs) can be grouped into three categories. The first category, practical QRNG, is built on fully trusted and calibrated devices and typically can generate randomness at amore » high speed by properly modeling the devices. The second category is self-testing QRNG, where verifiable randomness can be generated without trusting the actual implementation. The third category, semi-self-testing QRNG, is an intermediate category which provides a tradeoff between the trustworthiness on the device and the random number generation speed.« less

  15. 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.

  16. Optical Coherence Tomography Angiography for Detecting Choroidal Neovascularization Secondary to Choroidal Osteoma.

    PubMed

    Szelog, Jason T; Bonini Filho, Marco A; Lally, David R; de Carlo, Talisa E; Duker, Jay S

    2016-01-01

    Choroidal osteoma is an ossifying tumor that is found predominantly in the peripapillary and macular areas. It typically affects otherwise healthy females. Vision loss may occur secondary to the development of choroidal neovascularization (CNV). Fluorescein angiography (FA) remains the gold standard for diagnosing CNV; however, the use of optical coherence tomography angiography (OCTA) as an adjunct to FA is growing. In this report, a 16-year-old female with a large, unilateral peripapillary choroidal osteoma presented with blurred vision. Exam revealed scattered intraretinal hemorrhage, but FA was unable to detect CNV overlying the tumor. OCTA detected abnormal flow in the outer retina corresponding to a type 2 CNV. Following intravitreal anti-vascular endothelial growth factor therapy, the CNV regressed, the hemorrhage resolved, and there was less fluid. OCTA may be helpful in detecting CNV noninvasively in eyes in which FA is equivocal, such as those with choroidal osteoma.

  17. Computed tomographic angiography in evaluation of superficial temporal to middle cerebral artery bypass.

    PubMed

    Besachio, David A; Ziegler, Jordan I; Duncan, Timothy D; Wanebo, John S

    2010-01-01

    Catheter-directed digital subtraction angiography (DSA) is considered the standard for evaluation of superficial temporal to middle cerebral artery (STA-MCA) bypass patency. Few clinical investigations have been performed that evaluate the efficacy of computed tomographic angiography (CTA) in the assessment of extracranial-intracranial bypass. Using multi-detector row CTA, STA-MCA bypass patency was assessed in the initial postoperative period and several months afterward and compared with DSA. No significant difference was identified in the evaluation of graft patency between DSA and CTA. Although multiple modalities exist to evaluate STA-MCA bypass graft patency, the multidetector CTA is widely available and allows for rapid, accurate patency assessment. PMID:20498550

  18. [The clinical picture, fluorescence angiography and histologie of a ringmelanoma of the iris (author's transl)].

    PubMed

    Demeler, U; von Domarus, D

    1976-03-01

    Report on a rare case of an iris-ringmelanoma. Arising from the iris base the primary tumor spread in a continuous line along the anterior chamber angle and a shedding of tumor cells in other places of the iris surface could be stated as well. A unilateral dark spotted colouring of the iris with a secondary glaucoma was clinically observed. Gonioscopy, diaphanoscopy, 32P-test, and iris fluorescence-angiography aided the diagnosis. Fluorescence angiography appears to be of particular value in the diagnosis of malignant melanoma of the iris: The peculiar filling pattern seen at the pupillary border of the tumor has up to now only been found in malignant processes of the anterior uvea. The clinical tentative diagnosis of malignant ringmelanoma of the iris, could histopathologically be verified.

  19. 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.

  20. In vivo imaging of retinal hemodynamics with OCT angiography and Doppler OCT

    PubMed Central

    Huang, Shenghai; Shen, Meixiao; Zhu, Dexi; Chen, Qi; Shi, Ce; Chen, Zhongping; Lu, Fan

    2016-01-01

    Retinal hemodynamics is important for early diagnosis and precise monitoring in retinal vascular diseases. We propose a novel method for measuring absolute retinal blood flow in vivo using the combined techniques of optical coherence tomography (OCT) angiography and Doppler OCT. Doppler values can be corrected by Doppler angles extracted from OCT angiography images. A three-dimensional (3D) segmentation algorithm based on dynamic programming was developed to extract the 3D boundaries of optic disc vessels, and Doppler angles were calculated from 3D vessel geometry. The accuracy of blood flow from the Doppler OCT was validated using a flow phantom. The feasibility of the method was tested on a subject in vivo. The pulsatile retinal blood flow and the parameters for retinal hemodynamics were successfully obtained. PMID:26977370

  1. 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.

  2. Coronary computed tomography angiography and its increasing application in day to day cardiology practice.

    PubMed

    Markham, R; Murdoch, D; Walters, D L; Hamilton-Craig, C

    2016-01-01

    Coronary artery disease (CAD) is the leading single cause of death in Australia affecting around 1.4 million people. Coronary computed tomography angiography has an established role in the assessment of patients with low to intermediate pretest probability for CAD who have chest pain and is typically used with the aim to rule out significant coronary artery stenosis. Use was initially limited because of concerns over radiation exposure, a Medicare rebate restricted to specialist referrals and an absence of data supporting its use as an alternative to functional testing in patients with chest pain. Recent advances in scanner technology and image sequencing, along with data from randomised control trials, have addressed these issues and indicate that coronary computed tomography angiography will play a greater role in the assessment of CAD in the coming years. PMID:26813899

  3. The value of angiography in the surgical management of pancreatic disease.

    PubMed Central

    Appleton, G. V.; Bathurst, N. C.; Virjee, J.; Cooper, M. J.; Williamson, R. C.

    1989-01-01

    Selective visceral angiography should help to determine the nature and extent of pancreatic lesions and their suitability for resection. Between 1980 and 1987 coeliac and superior mesenteric angiograms were obtained in 76 patients considered for pancreatic resection. Anomalous arterial anatomy was delineated in 25%. Among arterial abnormalities observed in 42 patients (55%), increased or decreased vascularity and displacement were of limited diagnostic value, but encasement correctly predicted cancer in 18 of 21 cases and irresectability in nine of these. When present (17%), invasion or occlusion of the portal or superior mesenteric vein was even more accurate, indicating cancer in 12 of 13 cases and irresectability in 11 of these. Hepatic metastases were only detected in 7 of 15 patients (47%). Overall, angiography confirmed the diagnosis in 54%, localised the lesion in 64% and correctly forecast irresectability in 58%. Misleading data were obtained in five patients. There were no complications. Images fig. 1 fig. 2 fig. 3 fig. 4 fig. 5 PMID:2705733

  4. Contrast medium administration and image acquisition parameters in renal CT angiography: what radiologists need to know

    PubMed Central

    Saade, Charbel; Deeb, Ibrahim Alsheikh; Mohamad, Maha; Al-Mohiy, Hussain; El-Merhi, Fadi

    2016-01-01

    Over the last decade, exponential advances in computed tomography (CT) technology have resulted in improved spatial and temporal resolution. Faster image acquisition enabled renal CT angiography to become a viable and effective noninvasive alternative in diagnosing renal vascular pathologies. However, with these advances, new challenges in contrast media administration have emerged. Poor synchronization between scanner and contrast media administration have reduced the consistency in image quality with poor spatial and contrast resolution. Comprehensive understanding of contrast media dynamics is essential in the design and implementation of contrast administration and image acquisition protocols. This review includes an overview of the parameters affecting renal artery opacification and current protocol strategies to achieve optimal image quality during renal CT angiography with iodinated contrast media, with current safety issues highlighted. PMID:26728701

  5. Pulsatile Tinnitus with a Dural Arterio-Venous Fistula Diagnosed by Computed Tomography-Angiography

    PubMed Central

    Kim, Sujin; Byun, Jaeyong; Park, Moonsuh

    2013-01-01

    A 43 year-old female patient suffered the sudden onset of pulsatile tinnitus in the left ear 2 months ago. The tinnitus did not subside spontaneously and remained unchanged. The patient had no history of head trauma or surgery of the head and neck. The character of the tinnitus was pulsatile, and it was synchronous with the heart beat. Audiologic examinations were performed and all of the results were normal. Computed tomography with angiography was performed and evidence of an arterio-venous fistula (AVF) was found. 4-vessel angiography was performed to confirm the dural AVF between the external carotid artery and sigmoid sinus. Embolization of the feeder-vessels was done under a fluoroscope and 70% of the fistula flow was controlled after embolization and the tinnitus totally subsided during the embolization. PMID:24653921

  6. 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.

  7. A model-based reconstruction method for 3-D rotational coronary angiography

    PubMed Central

    Xie, Lizhe; Hu, Yining; Nunes, Jean-Claude; Bellanger, Jean-Jacques; Bedossa, Marc; Luo, Limin; Toumoulin, Christine

    2010-01-01

    This paper presents a model-based reconstruction method of the coronary tree from a few number of projections in rotational angiography imaging. The reconstruction relies on projections acquired at a same cardiac phase and an energy function minimization that aims to lead the deformation of the 3D model to fit projection data whereas preserving coherence both in time and space. Some preliminary results are provided on simulated rotational angiograms. PMID:21096600

  8. 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.

  9. 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.

  10. Contrast Enhancement of the Right Ventricle during Coronary CT Angiography – Is It Necessary?

    PubMed Central

    Kok, Madeleine; Kietselaer, Bas L. J. H.; Mihl, Casper; Altintas, Sibel; Nijssen, Estelle C.; Wildberger, Joachim E.; Das, Marco

    2015-01-01

    Purpose It is unclear if prolonged contrast media injection, to improve right ventricular visualization during coronary CT angiography, leads to increased detection of right ventricle pathology. The purpose of this study was to evaluate right ventricle enhancement and subsequent detection of right ventricle disease during coronary CT angiography. Materials and Methods 472 consecutive patients referred for screening coronary CT angiography were retrospectively evaluated. Every patient underwent multidetector-row CT of the coronary arteries: 128x 0.6mm coll., 100-120kV, rot. time 0.28s, ref. mAs 350 and received an individualized (P3T) contrast bolus injection of iodinated contrast medium (300 mgI/ml). Patient data were analyzed to assess right ventricle enhancement (HU) and right ventricle pathology. Image quality was defined good when right ventricle enhancement >200HU, moderate when 140-200HU and poor when <140HU. Results Good image quality was found in 372 patients, moderate in 80 patients and poor in 20 patients. Mean enhancement of the right ventricle cavity was 268HU±102. Patients received an average bolus of 108±24 ml at an average peak flow rate of 6.1±2.2 ml/s. In only three out of 472 patients (0.63%) pathology of the right ventricle was found (dilatation) No other right ventricle pathology was detected. Conclusion Right ventricle pathology was detected in three out of 472 patients; the dilatation observed in these three cases may have been picked up even without dedicated enhancement of the right ventricle. Based on our findings, right ventricle enhancement can be omitted during screening coronary CT angiography. PMID:26029905

  11. 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

  12. Wall-to-lumen ratio of intracranial arteries measured by indocyanine green angiography

    PubMed Central

    Nakagawa, Daichi; Shojima, Masaaki; Yoshino, Masanori; Kin, Taichi; Imai, Hideaki; Nomura, Seiji; Saito, Toki; Nakatomi, Hirofumi; Oyama, Hiroshi; Saito, Nobuhito

    2016-01-01

    Background: The wall-to-lumen ratio (WLR) is an important parameter in vascular medicine because it indicates the character of vascular wall as well as the degree of stenosis. Despite the advances in medical imaging technologies, it is still difficult to measure the thin-walled normal intracranial arteries, and the reports on the WLR of normal intracranial artery are limited. It might be possible to calculate the WLR using the indocyanine green (ICG) angiography, which is used to observe intracranial vessels during microsurgery. Purpose: To evaluate the WLR of normal intracranial arteries using ICG angiography. Materials and Methods: From the three cases in which ICG angiography was recorded with a ruler during microsurgery, 20 measurement points were chosen for the analysis. The ICG was injected intravenously with a dose of 0.2 mg/kg, and the vessels were inspected at high magnification using an operating microscope equipped with near-infrared illumination system. The vessel outer diameter and the luminal diameter were measured using the images before and after the ICG arrival based on the pixel ratio method using a ruler as reference, respectively. The WLR was calculated as 0.5 × (vessel outer diameter − vessel luminal diameter). Results: The WLR (mean ± standard deviation) of normal intracranial arteries was 0.086 ± 0.022. The WLR tended to be high in small arteries. Conclusion: The WLR of normal intracranial arteries calculated using ICG angiography was consistent with the WLR reported in the previous reports based on human autopsy.

  13. Spontaneous closure of posttraumatic high-flow carotid-cavernous fistula following cerebral angiography

    PubMed Central

    Meena, Ugan Singh; Gupta, Pankaj; Shrivastava, Trilochan; Purohit, Devendra

    2016-01-01

    Traumatic carotid-cavernous fistula (TCCF) is a direct communication between cavernous portion of the internal carotid artery (ICA) and cavernous sinus due to tear in ICA. Most of the cases are treated by endovascular embolization. Spontaneous resolution of high-flow TCCFs is extremely rare. We report a case of posttraumatic, direct, high-flow carotid cavernous fistula (Barrow type A) that resolved spontaneously after cerebral angiography. PMID:27057229

  14. 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

  15. Wall-to-lumen ratio of intracranial arteries measured by indocyanine green angiography

    PubMed Central

    Nakagawa, Daichi; Shojima, Masaaki; Yoshino, Masanori; Kin, Taichi; Imai, Hideaki; Nomura, Seiji; Saito, Toki; Nakatomi, Hirofumi; Oyama, Hiroshi; Saito, Nobuhito

    2016-01-01

    Background: The wall-to-lumen ratio (WLR) is an important parameter in vascular medicine because it indicates the character of vascular wall as well as the degree of stenosis. Despite the advances in medical imaging technologies, it is still difficult to measure the thin-walled normal intracranial arteries, and the reports on the WLR of normal intracranial artery are limited. It might be possible to calculate the WLR using the indocyanine green (ICG) angiography, which is used to observe intracranial vessels during microsurgery. Purpose: To evaluate the WLR of normal intracranial arteries using ICG angiography. Materials and Methods: From the three cases in which ICG angiography was recorded with a ruler during microsurgery, 20 measurement points were chosen for the analysis. The ICG was injected intravenously with a dose of 0.2 mg/kg, and the vessels were inspected at high magnification using an operating microscope equipped with near-infrared illumination system. The vessel outer diameter and the luminal diameter were measured using the images before and after the ICG arrival based on the pixel ratio method using a ruler as reference, respectively. The WLR was calculated as 0.5 × (vessel outer diameter − vessel luminal diameter). Results: The WLR (mean ± standard deviation) of normal intracranial arteries was 0.086 ± 0.022. The WLR tended to be high in small arteries. Conclusion: The WLR of normal intracranial arteries calculated using ICG angiography was consistent with the WLR reported in the previous reports based on human autopsy. PMID:27695538

  16. Arteriovenous fistula complicating iliac artery pseudo aneurysm: diagnosis by CT angiography.

    PubMed

    Huawei, L; Bei, D; Huan, Z; Zilai, P; Aorong, T; Kemin, C

    2002-01-01

    Fistula formation to the inferior vena cava is a rare complication of aortic aneurysm which is often misdiagnosed clinically. In one hundred of reported arteriocaval fistulae, none was originating from the right common iliac artery. We report a case of ileo-caval fistula due to a iatrogenic pseudoaneurysm. High resolution 3D imaging using breath-hold CT angiography is highly specific in identifying the location, extent of the aortocaval fistula as well as the neighbouring anatomic structures.

  17. 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.

  18. 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.

  19. 3D rotational angiography: use of propeller rotation for the evaluation of intracranial aneurysms.

    PubMed

    Gauvrit, Jean-Yves; Leclerc, Xavier; Vermandel, Maximilien; Lubicz, Boris; Despretz, David; Lejeune, Jean-Paul; Rousseau, Jean; Pruvo, Jean-Pierre

    2005-01-01

    We compared two methods of 3D digital subtraction angiography (DSA)--propeller and standard rotation--for the assessment of aneurysmal morphology and its relation to neighboring vessels. Aneurysms were correctly visualized and localized with both techniques. 3D DSA with propeller rotation technique seems to be effective and allows us to reduce the amount of contrast material related to a shortened acquisition time. Technical progress including propeller rotation allows a larger range of rotation and faster rotational speeds.

  20. Cardiothoracic ratio within the “normal” range independently predicts mortality in patients undergoing coronary angiography

    PubMed Central

    Zaman, M Justin S; Sanders, Julie; Crook, Angela M; Feder, Gene; Shipley, Martin; Timmis, Adam; Hemingway, Harry

    2007-01-01

    Objective To determine whether cardiothoracic ratio (CTR), within the range conventionally considered normal, predicted prognosis in patients undergoing coronary angiography. Design Cohort study with a median of 7‐years follow‐up. Setting Consecutive patients undergoing coronary angiography at Barts and The London National Health Service (NHS) Trust. Subjects 1005 patients with CTRs measured by chest radiography, and who subsequently underwent coronary angiography. Of these patients, 7.3% had a CTR ⩾0.5 and were excluded from the analyses. Outcomes All‐cause mortality and coronary event (non‐fatal myocardial infarction or coronary death). Adjustments were made for age, left ventricular dysfunction, ACE inhibitor treatment, body mass index, number of diseased coronary vessels and past coronary artery bypass graft. Results The risk of death was increased among patients with a CTR in the upper part of the normal range. In total, 94 (18.9%) of those with a CTR below the median of 0.42 died compared with 120 (27.8%) of those with a CTR between 0.42 and 0.49 (log rank test p<0.001). After adjusting for potential confounders, this increased risk remained (adjusted HR 1.45, 95% CI 1.03 to 2.05). CTR, at values below 0.5, was linearly related to the risk of coronary event (test for trend p = 0.024). Conclusion : In patients undergoing coronary angiography, CTR between 0.42 and 0.49 was associated with higher mortality than in patients with smaller hearts. There was evidence of a continuous increase in risk with higher CTR. These findings, along with those in healthy populations, question the conventional textbook cut‐off point of ⩾0.5 being an abnormal CTR. PMID:17164481

  1. 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.

  2. Congenital subcutaneous arteriovenous malformation in a puppy: diagnosis with CT angiography.

    PubMed

    Proks, Pavel; Stehlik, Ladislav; Paninarova, Michaela; Irova, Katarina; Lorenzova, Jana; Necas, Alois

    2015-10-01

    A 4-month-old, 20 kg, intact male, cane corso dog was presented with a slowly growing subcutaneous lesion on the left caudoventral abdominal wall. Ultrasound and computed tomography angiography revealed a subcutaneous plexus of aberrant tortuous vessels directly connected with the superficial branch of the deep circumflex iliac artery and vein. The arteriovenous malformation (AVM) was successfully surgically removed. Early recognition and surgical removal of AVM can have excellent cosmetic results and prevents potential cardiovascular complications. PMID:26175066

  3. 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.

  4. Magnetic Resonance Angiography of the Peripheral Vessels in Patients with Peripheral Arterial Occlusive Disease: When Is an Additional Conventional Angiography Required?

    SciTech Connect

    Janka, R. Wenkel, E.; Fellner, C.; Lang, W.; Bautz, W.; Uder, M.

    2006-04-15

    The purpose of this work was to find out how often the clinician asks for a conventional angiography (CA) in patients with peripheral arterial occlusive disease (PAOD) after a magnetic resonance angiography (MRA) has been performed and how often the CA reveals additional information for therapy planning. Quality criteria for the MRA were defined and tested to see whether they can predict the need for an additional CA. In this prospective study, 81 patients suffering from PAOD (Fontaine classification IIa, n = 13; IIb, n = 33; III, n = 10; IV, n = 25) were examined with a 1.5-T MR-scanner with dedicated coils using a step-by-step technique. The vascular surgeon decided whether he could plan the therapy on the basis of the MRA or if he needed an additional CA. The MRA was assessed in terms of the image quality of the MRA and regarding therapeutic management of the patient in a two-grade scale: sufficient and insufficient. In 27/81 (33%) patients, the clinician asked for a CA, which revealed new information in only 11 patients. The relative number of MRAs with insufficient image quality was significantly higher (p < 0.01) in the group with additional information on CA (8/11) compared to the group without additional information (0/16). The assessment of an MRA based on image quality and regarding therapeutic management of the patient might reduce the number of CAs for therapy planning in patients with PAOD.

  5. Prevention of contrast-induced AKI: a review of published trials and the design of the prevention of serious adverse events following angiography (PRESERVE) trial.

    PubMed

    Weisbord, Steven D; Gallagher, Martin; Kaufman, James; Cass, Alan; Parikh, Chirag R; Chertow, Glenn M; Shunk, Kendrick A; McCullough, Peter A; Fine, Michael J; Mor, Maria K; Lew, Robert A; Huang, Grant D; Conner, Todd A; Brophy, Mary T; Lee, Joanne; Soliva, Susan; Palevsky, Paul M

    2013-09-01

    Contrast-induced AKI (CI-AKI) is a common condition associated with serious, adverse outcomes. CI-AKI may be preventable because its risk factors are well characterized and the timing of renal insult is commonly known in advance. Intravenous (IV) fluids and N-acetylcysteine (NAC) are two of the most widely studied preventive measures for CI-AKI. Despite a multitude of clinical trials and meta-analyses, the most effective type of IV fluid (sodium bicarbonate versus sodium chloride) and the benefit of NAC remain unclear. Careful review of published trials of these interventions reveals design limitations that contributed to their inconclusive findings. Such design limitations include the enrollment of small numbers of patients, increasing the risk for type I and type II statistical errors; the use of surrogate primary endpoints defined by small increments in serum creatinine, which are associated with, but not necessarily causally related to serious, adverse, patient-centered outcomes; and the inclusion of low-risk patients with intact baseline kidney function, yielding low event rates and reduced generalizability to a higher-risk population. The Prevention of Serious Adverse Events following Angiography (PRESERVE) trial is a randomized, double-blind, multicenter trial that will enroll 8680 high-risk patients undergoing coronary or noncoronary angiography to compare the effectiveness of IV isotonic sodium bicarbonate versus IV isotonic sodium chloride and oral NAC versus oral placebo for the prevention of serious, adverse outcomes associated with CI-AKI. This article discusses key methodological issues of past trials investigating IV fluids and NAC and how they informed the design of the PRESERVE trial.

  6. Prevention of Contrast-Induced AKI: A Review of Published Trials and the Design of the Prevention of Serious Adverse Events following Angiography (PRESERVE) Trial

    PubMed Central

    Gallagher, Martin; Kaufman, James; Cass, Alan; Parikh, Chirag R.; Chertow, Glenn M.; Shunk, Kendrick A.; McCullough, Peter A.; Fine, Michael J.; Mor, Maria K.; Lew, Robert A.; Huang, Grant D.; Conner, Todd A.; Brophy, Mary T.; Lee, Joanne; Soliva, Susan; Palevsky, Paul M.

    2013-01-01

    Summary Contrast-induced AKI (CI-AKI) is a common condition associated with serious, adverse outcomes. CI-AKI may be preventable because its risk factors are well characterized and the timing of renal insult is commonly known in advance. Intravenous (IV) fluids and N-acetylcysteine (NAC) are two of the most widely studied preventive measures for CI-AKI. Despite a multitude of clinical trials and meta-analyses, the most effective type of IV fluid (sodium bicarbonate versus sodium chloride) and the benefit of NAC remain unclear. Careful review of published trials of these interventions reveals design limitations that contributed to their inconclusive findings. Such design limitations include the enrollment of small numbers of patients, increasing the risk for type I and type II statistical errors; the use of surrogate primary endpoints defined by small increments in serum creatinine, which are associated with, but not necessarily causally related to serious, adverse, patient-centered outcomes; and the inclusion of low-risk patients with intact baseline kidney function, yielding low event rates and reduced generalizability to a higher-risk population. The Prevention of Serious Adverse Events following Angiography (PRESERVE) trial is a randomized, double-blind, multicenter trial that will enroll 8680 high-risk patients undergoing coronary or noncoronary angiography to compare the effectiveness of IV isotonic sodium bicarbonate versus IV isotonic sodium chloride and oral NAC versus oral placebo for the prevention of serious, adverse outcomes associated with CI-AKI. This article discusses key methodological issues of past trials investigating IV fluids and NAC and how they informed the design of the PRESERVE trial. PMID:23660180

  7. En face OCT angiography demonstrates flow in early type 3 neovascularization (retinal angiomatous proliferation)

    PubMed Central

    Dansingani, K K; Naysan, J; Freund, K B

    2015-01-01

    Introduction The characteristics of type 3 neovascularization (NV), also known as retinal angiomatous proliferation, have been well described clinically, as well as with fluorescein angiography (FA), indocyanine green angiography, and optical coherence tomography (OCT). OCT angiography (OCT-A) is a novel and non-invasive technique for imaging retinal microvasculature by detecting changes, with respect to time, in reflectivity related to blood flow. Method In this case series, we describe two patients who presented with type 3 NV and underwent clinical examination and multimodal imaging, including OCT-A. Results In the first patient, OCT-A demonstrated flow within two separate lesions in the same eye, one of which was only weakly detected by FA. In the second patient, sequential OCT-A demonstrated a reduction in intralesional flow following intravitreal therapy. Conclusions OCT-A may have a role in the early diagnosis of type 3 NV and in assessing the response to treatment. Further studies are needed to determine sensitivity and specificity. PMID:25744441

  8. Multiresolution image registration in digital x-ray angiography with intensity variation modeling.

    PubMed

    Nejati, Mansour; Pourghassem, Hossein

    2014-02-01

    Digital subtraction angiography (DSA) is a widely used technique for visualization of vessel anatomy in diagnosis and treatment. However, due to unavoidable patient motions, both externally and internally, the subtracted angiography images often suffer from motion artifacts that adversely affect the quality of the medical diagnosis. To cope with this problem and improve the quality of DSA images, registration algorithms are often employed before subtraction. In this paper, a novel elastic registration algorithm for registration of digital X-ray angiography images, particularly for the coronary location, is proposed. This algorithm includes a multiresolution search strategy in which a global transformation is calculated iteratively based on local search in coarse and fine sub-image blocks. The local searches are accomplished in a differential multiscale framework which allows us to capture both large and small scale transformations. The local registration transformation also explicitly accounts for local variations in the image intensities which incorporated into our model as a change of local contrast and brightness. These local transformations are then smoothly interpolated using thin-plate spline interpolation function to obtain the global model. Experimental results with several clinical datasets demonstrate the effectiveness of our algorithm in motion artifact reduction.

  9. Image-based device tracking for the co-registration of angiography and intravascular ultrasound images.

    PubMed

    Wang, Peng; Chen, Terrence; Ecabert, Olivier; Prummer, Simone; Ostermeier, Martin; Comaniciu, Dorin

    2011-01-01

    The accurate and robust tracking of catheters and transducers employed during image-guided coronary intervention is critical to improve the clinical workflow and procedure outcome. Image-based device detection and tracking methods are preferred due to the straightforward integration into existing medical equipments. In this paper, we present a novel computational framework for image-based device detection and tracking applied to the co-registration of angiography and intravascular ultrasound (IVUS), two modalities commonly used in interventional cardiology. The proposed system includes learning-based detections, model-based tracking, and registration using the geodesic distance. The system receives as input the selection of the coronary branch under investigation in a reference angiography image. During the subsequent pullback of the IVUS transducers, the system automatically tracks the position of the medical devices, including the IVUS transducers and guiding catheter tips, under fluoroscopy imaging. The localization of IVUS transducers and guiding catheter tips is used to continuously associate an IVUS imaging plane to the vessel branch under investigation. We validated the system on a set of 65 clinical cases, with high accuracy (mean errors less than 1.5mm) and robustness (98.46% success rate). To our knowledge, this is the first reported system able to automatically establish a robust correspondence between the angiography and IVUS images, thus providing clinicians with a comprehensive view of the coronaries.

  10. Mediation and moderation of the effects of watching the angiography screen on patients.

    PubMed

    Shiloh, Shoshana; Drori, Erga; Peleg, Shira; Banai, Shmuel; Finkelstein, Ariel

    2016-10-01

    It has been reported that allowing patients to watch the coronary angiography screen during the procedure results in psychological benefits. This study aimed to investigate the roles of illness perceptions as mediators of this outcome and to examine whether individual differences in monitoring coping style moderated these effects. The experiment compared patients who were instructed to watch the monitor screen (n = 57) with those who were not (n = 51). Questionnaires were used to measure the research variables at one day and one month after the procedure. Results showed that watching the angiography screen increased patients' personal and treatment control perceptions that mediated changes in self-assessed health, risk perceptions, negative affect, general and diet outcome expectancies, and diet and physical activity intentions. The behavior-related outcomes were moderated by monitoring coping style. These findings illustrate the significance of illness perceptions, perceived control and monitoring coping style in achieving desirable outcomes among patients undergoing coronary angiography, and reveal opportunities for interventions using medical imaging technologies. PMID:26740003

  11. Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography

    PubMed Central

    Zhang, Anqi; Zhang, Qinqin; Wang, Ruikang K.

    2015-01-01

    Current optical coherence tomography (OCT) based micro-angiography is prone to a projection (or tailing) effect due to the high scattering property of blood within overlying patent vessels, creating artifacts that interfere with the interpretation of retinal angiographic results. In this work, the projection effect in OCT micro-angiography is examined and its causality is explained by strong light scattering and photon propagation within blood. A simple practical approach is then introduced to minimize these artifacts presented in the outer retinal avascular space, especially useful for examining clinical cases with choroidal neovascularization (CNV). Demonstrated through in-vivo human posterior eye imaging of healthy and CNV subjects, the proposed method is shown effective to eliminate the projection artifacts in outer retinal space of OCT micro-angiography, resulting in better visualization of the pathological neovascularization when compared with the current common approaches. In addition, it is also shown that the proposed method is applicable to minimize the projection artifacts appearing in deep retinal layers. PMID:26504660

  12. Thyroid Function, Prevalent Coronary Heart Disease, and Severity of Coronary Atherosclerosis in Patients Undergoing Coronary Angiography

    PubMed Central

    Ling, Yan; Jiang, Jingjing; Gui, Minghui; Liu, Lin; Aleteng, Qiqige; Wu, Bingjie; Wang, Shanshan; Liu, Xiaojing; Gao, Xin

    2015-01-01

    This study investigated if free T4 and TSH concentrations or thyroid function categories were associated with prevalent CHD and the severity of coronary atherosclerosis in a population undergoing coronary angiography. This was a cross-sectional study including 1799 patients who were consecutively admitted and underwent coronary angiography. We evaluated the severity of coronary atherosclerosis using Gensini score. In the entire study population, free T4 level was inversely associated with prevalent CHD (OR = 0.95, 95% CI 0.91–0.99, P = 0.01) and the natural log-transformed Gensini score (ln(Gensini score)) (β = −0.03, 95% CI −0.05–−0.01, P = 0.005). The odds of CHD increased gradually across hyperthyroidism, subclinical hypothyroidism, and overt hypothyroidism groups using the euthyroid group as the reference, and the trend is borderline significant (P for trend = 0.051). When comparing to the euthyroid group, ln(Gensini score) of the overt hypothyroidism group was significantly higher (P = 0.009), but the trend was not significant (P for trend = 0.08). A significant association of thyroid function with CHD or ln(Gensini score) in euthyroid patients was not observed. The present study demonstrated an association of thyroid function with prevalent CHD and the severity of coronary atherosclerosis in a population undergoing coronary angiography. However, this association was not observed in euthyroid individuals. PMID:26770196

  13. The use of gated radionuclide angiography in the diagnosis of cardiac contusion

    SciTech Connect

    Fenner, J.E.; Knopp, R.; Lee, B.; dos Santos, P.A.; Wessel, R.J.; Dang, C.V.; Parks, S.N.

    1984-09-01

    No currently used diagnostic test is an accurate predictor of patients who will develop morbidity or mortality from cardiac contusion. In a prospective study we used gated cardiac radionuclide angiography to assess cardiac function in 30 patients with blunt chest trauma, and we compared the results of this test with those of other diagnostic studies for cardiac contusion to determine whether gated angiography is a more accurate predictor of serious cardiac injury. Diagnostic tests included the following: serial electrocardiograms (ECG), serial creatine phosphokinase muscle-brain isoenzyme (CPK-MB) and lactic dehydrogenase (LDH) isoenzymes, gated cardiac radionuclide angiography, and technetium-99m (Tc-99m) pyrophosphate scintigraphy. Abnormal studies were present in 26 patients; 22 showed abnormalities in CPK-MB, 19 on ECG, and five on gated scan. No patient demonstrated an abnormal Tc-99m pyrophosphate scan or abnormal elevation of LDH isoenzyme. Although no diagnostic test was predictive of morbidity and mortality, CPK-MB isoenzyme was the only test to correlate with morbidity and mortality. Morbidity and mortality correlated most closely with the number of associated major injuries and the presence of hypotension or hypoxia.

  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. Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography.

    PubMed

    Zhang, Anqi; Zhang, Qinqin; Wang, Ruikang K

    2015-10-01

    Current optical coherence tomography (OCT) based micro-angiography is prone to a projection (or tailing) effect due to the high scattering property of blood within overlying patent vessels, creating artifacts that interfere with the interpretation of retinal angiographic results. In this work, the projection effect in OCT micro-angiography is examined and its causality is explained by strong light scattering and photon propagation within blood. A simple practical approach is then introduced to minimize these artifacts presented in the outer retinal avascular space, especially useful for examining clinical cases with choroidal neovascularization (CNV). Demonstrated through in-vivo human posterior eye imaging of healthy and CNV subjects, the proposed method is shown effective to eliminate the projection artifacts in outer retinal space of OCT micro-angiography, resulting in better visualization of the pathological neovascularization when compared with the current common approaches. In addition, it is also shown that the proposed method is applicable to minimize the projection artifacts appearing in deep retinal layers. PMID:26504660

  16. 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.

  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. Multiresolution image registration in digital x-ray angiography with intensity variation modeling.

    PubMed

    Nejati, Mansour; Pourghassem, Hossein

    2014-02-01

    Digital subtraction angiography (DSA) is a widely used technique for visualization of vessel anatomy in diagnosis and treatment. However, due to unavoidable patient motions, both externally and internally, the subtracted angiography images often suffer from motion artifacts that adversely affect the quality of the medical diagnosis. To cope with this problem and improve the quality of DSA images, registration algorithms are often employed before subtraction. In this paper, a novel elastic registration algorithm for registration of digital X-ray angiography images, particularly for the coronary location, is proposed. This algorithm includes a multiresolution search strategy in which a global transformation is calculated iteratively based on local search in coarse and fine sub-image blocks. The local searches are accomplished in a differential multiscale framework which allows us to capture both large and small scale transformations. The local registration transformation also explicitly accounts for local variations in the image intensities which incorporated into our model as a change of local contrast and brightness. These local transformations are then smoothly interpolated using thin-plate spline interpolation function to obtain the global model. Experimental results with several clinical datasets demonstrate the effectiveness of our algorithm in motion artifact reduction. PMID:24469684

  19. Incidence and Risk Factors for Rebleeding during Cerebral Angiography for Ruptured Intracranial Aneurysms

    PubMed Central

    Lim, Yong Cheol; Kim, Chang-Hyun; Kim, Yong Bae; Joo, Jin-Yang; Shin, Yong Sam

    2015-01-01

    Purpose The purpose was to evaluate the incidence and risk factors for rebleeding during cerebral angiography in ruptured intracranial aneurysms. Materials and Methods Among 1896 patients with ruptured intracranial aneurysms between September 2006 and December 2013, a total of 11 patients who experienced rebleeding of the ruptured aneurysms during digital subtraction angiography (DSA) were recruited in this study. Results There were 184 patients (9.7%) who had suffered rebleeding prior to the securing procedure. Among them, 11 patients experienced rebleeding during DSA and other 173 patients at a time other than DSA. Eight (72.7%) of the 11 patients experienced rebleeding during three-dimensional rotational angiography (3DRA). The incidence of rebleeding during DSA was 0.6% in patients with ruptured intracranial aneurysms. Multivariate logistic regression analysis showed that aneurysm location in anterior circulation [odds ratio=14.286; 95% confidence interval (CI), 1.877 to 250.0; p=0.048] and higher aspect ratio (odds ratio=3.040; 95% CI, 1.896 to 10.309; p=0.041) remained independent risk factors for rebleeding during DSA. Conclusion Ruptured aneurysms located in anterior circulation with a high aspect ratio might have the risk of rebleeding during DSA, especially during 3DRA. PMID:25683988

  20. 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.

  1. Automated Quantification of Capillary Nonperfusion Using Optical Coherence Tomography Angiography in Diabetic Retinopathy

    PubMed Central

    Hwang, Thomas S; Gao, Simon S; Liu, Liang; Lauer, Andreas K.; Bailey, Steven T; Flaxel, Christina J; Wilson, David J; Huang, David; Jia, Yali

    2016-01-01

    Importance Macular ischemia is a key feature of diabetic retinopathy (DR). Quantification of macular ischemia has potential as a biomarker for DR. Objective To assess the feasibility of automated quantification of capillary nonperfusion as a potential sign of macular ischemia using optical coherence tomography (OCT) angiography. Design, Setting, and Participants An observational study conducted in a tertiary, subspecialty, academic practice evaluated macular nonperfusion with 6 × 6-mm OCT angiography obtained with commercially available 70-kHz OCT and fluorescein angiography (FA). The study was conducted from January 22 to September 18, 2014. Data analysis was performed from October 1, 2014, to April 7, 2015. Participants included 12 individuals with normal vision serving as controls and 12 patients with various levels of DR. Main Outcomes and Measures Preplanned primary measures were parafoveal and perifoveal vessel density, total avascular area, and foveal avascular zone as detected with 6 × 6-mm OCT angiography and analyzed using an automated algorithm. Secondary measures included the agreement of the avascular area between the OCT angiogram and FA. Results Compared with the 12 healthy controls (11 women; mean [SD] age, 54.2 [14.2] years), the 12 participants with DR (4 women; mean [SD] age, 55.1 [12.1] years) had reduced parafoveal and perifoveal vessel density by 12.6% (95% CI, 7.7%-17.5%; P < .001) and 10.4% (95% CI, 6.8%-14.1%; P < .001), respectively. Total avascular area and foveal avascular zone area were greater in eyes with DR by 0.82 mm2 (95% CI. 0.65-0.99 mm2; P = .02) and 0.16 mm2 (95% CI, 0.05-0.28 mm2; P < .001). The agreement between the vascular areas in the OCT angiogram and FA had a κ value of 0.45 (95% CI, 0.21-0.70; P < .001). Total avascular area in the central 5.5-mm-diameter area distinguished eyes with DR from control eyes with 100% sensitivity and specificity. Conclusions and Relevance Avascular area analysis with an automated

  2. 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

  3. Effect of diltiazem on myocardial infarct size estimated by enzyme release, serial thallium-201 single-photon emission computed tomography and radionuclide angiography

    SciTech Connect

    Zannad, F.; Amor, M.; Karcher, G.; Maurin, P.; Ethevenot, G.; Sebag, C.; Bertrand, A.; Pernot, C.; Gilgenkrantz, J.M.

    1988-06-01

    Diltiazem is a calcium antagonist with demonstrated experimental cardioprotective effects. Its effects on myocardial infarct size were studied in 34 patients admitted within 6 hours after the first symptoms of acute myocardial infarction. These patients were randomized, double-blind to placebo or diltiazem (10-mg intravenous bolus followed by 15 mg/hr intravenous infusion during 72 hours, followed by 4 X 60 mg during 21 days). Myocardial infarct size was assessed by plasma creatine kinase and creatine kinase-MB indexes, perfusion defect scores using single-photon emission computed tomography with thallium-201 and left ventricular ejection fraction measured by radionuclide angiography. Tomographic and angiographic scanning was performed serially before randomization, after 48 hours and 21 days later. Groups were comparable in terms of age, sex, inclusion time and baseline infarct location and size. Results showed no difference in creatine kinase and creatine kinase-MB data between controls and treated patients, a significant decrease in the perfusion defect scores in the diltiazem group (+0.1 +/- 3.0 placebo vs -2.2 +/- 1.9 diltiazem, p less than 0.02) and a better ejection fraction recovery in the diltiazem group (-4.2 +/- 7.4 placebo vs +7.7 +/- 11.2 diltiazem, p less than 0.05). Myocardial infarct size estimates from perfusion defect scores and enzyme data were closely correlated. These preliminary results suggest that diltiazem may reduce ischemic injury in acute myocardial infarction.

  4. Diagnostic performance of quantitative coronary computed tomography angiography and quantitative coronary angiography to predict hemodynamic significance of intermediate-grade stenoses.

    PubMed

    Ghekiere, Olivier; Dewilde, Willem; Bellekens, Michel; Hoa, Denis; Couvreur, Thierry; Djekic, Julien; Coolen, Tim; Mancini, Isabelle; Vanhoenacker, Piet K; Dendale, Paul; Nchimi, Alain

    2015-12-01

    Fractional flow reserve (FFR) during invasive coronary angiography has become an established tool for guiding treatment. However, only one-third of intermediate-grade coronary artery stenosis (ICAS) are hemodynamically significant and require coronary revascularization. Additionally, the severity of stenosis visually established by coronary computed tomography angiography (CCTA) does not reliably correlate with the functional severity. Therefore, additional angiographic morphologic descriptors affecting hemodynamic significance are required. To evaluate quantitative stenosis analysis and plaque descriptors by CCTA in predicting the hemodynamic significance of ICAS and to compare it with quantitative catheter coronary angiography (QCA). QCA was performed in 65 patients (mean age 63 ± 9 years; 47 men) with 76 ICAS (40-70%) on CCTA. Plaque descriptors were determined including circumferential extent of calcification, plaque composition, minimal lumen diameter (MLD) and area, diameter stenosis percentage (Ds %), area stenosis percentage and stenosis length on CCTA. MLD and Ds % were also analyzed on QCA. FFR was measured on 52 ICAS lesions on CCTA and QCA. The diagnostic values of the best CCTA and QCA descriptors were calculated for ICAS with FFR ≤ 0.80. Of the 76 ICAS on CCTA, 52 (68%) had a Ds % between 40 and 70% on QCA. Significant intertechnique correlations were found between CCTA and QCA for MLD and Ds % (p < 0.001). In 17 (33%) of the 52 ICAS lesions on QCA, FFR values were ≤ 0.80. Calcification circumference extent (p = 0.50) and plaque composition assessment (p = 0.59) did not correlate with the hemodynamic significance. Best predictors for FFR ≤ 0.80 stenosis were ≤ 1.35 mm MLD (82% sensitivity, 66% specificity), and ≤ 2.3 mm(²) minimal lumen area (88% sensitivity, 60% specificity) on CCTA, and ≤ 1.1 mm MLD (59% sensitivity, 77% specificity) on QCA. Quantitative CCTA and QCA poorly predict hemodynamic significance of ICAS, though CCTA seems to

  5. Theoretical and experimental comparison of image signal and noise for dual-energy subtraction angiography and conventional x-ray angiography

    NASA Astrophysics Data System (ADS)

    Burton, Christiane S.; Mayo, John R.; Cunningham, I. A.

    2015-03-01

    Cardiovascular disease is currently the leading cause of mortality worldwide. Digital subtraction angiography (DSA) is widely used to enhance the visibility of small vessels and vasculature obscurred by overlying bone and lung fields by subtracting a mask and contrast image. However, motion between these mask and contrast images can introduce artifacts that can render a study non-diagnostic. This makes DSA particularly unsuccessful for cardiac imaging. A method called dual-energy, or energy subtraction angiography (ESA), was proposed in the past as an alternative for vascular imaging, however it was not pursued because experimental results suggested that image quality was deemed as poor and inferior to DSA. Image quality for angiography comes down to iodine signal and noise. In this paper we investigate the fundamental iodine signal and noise analysis of ESA and compare it to DSA. Method: We developed a polyenergetic and monoenergetic theoretical model for iodine signal and noise for both ESA and DSA. We validated our polyenergetic model by experiment where ESA and DSA images of a vascular phantom were acquired using an x-ray system with a flat panel CsI Xmaru1215CF-MPTM (Rayence Co., Ltd., Republic of Korea) detector. For ESA low and high applied tube voltages of 50 kV and 120 kV (2.5 mmCu), respectively, and for DSA the applied tube voltage was 80 kV. Iodine signal-to-noise ratio (SNR) per entrance exposure was calculated for each iodine concentration for both ESA and DSA. Results: Our measured iodine SNR agreed well with theoretical calculations. Iodine SNR for ESA was relatively higher than DSA for low iodine mass loadings, and as iodine mass loading increases iodine SNR decreases. Conclusions: We have developed a model for iodine SNR for both DSA and ESA. Our model was validated with experiment and showed excellent agreement. We have shown that there is potential for obtaining iodine-specific images using ESA that are similar to DSA.

  6. Dual-Axis Rotational Coronary Angiography: A New Technique for Detecting Graft Coronary Vasculopathy in Pediatric Heart Transplant Recipients

    PubMed Central

    Gudausky, Todd M.; Pelech, Andrew N.; Stendahl, Gail; Tillman, Kathryn; Mattice, Judy; Berger, Stuart; Zangwill, Steven

    2016-01-01

    Annual surveillance coronary angiograpyhy to screen for graft coronary vasculopathy is routine practice after orthotopic heart transplantation. Traditionally, this is performed with direct coronary angiography using static single-plane or biplane angiography. Recently, technological advances have made it possible to perform dual-axis rotational coronary angiography (RA). This technique differs from standard static single-plane or biplane angiography in that a single detector is preprogrammed to swing through a complex 80° arc during a single injection. It has the advantage of providing a perspective of the vessels from a full arc of images rather than from one or two static images per contrast injection. The current study evaluated two coronary angiography techniques used consecutively at a single center to evaluate pediatric heart transplant recipients for graft coronary vasculopathy. A total of 23 patients underwent routine coronary angiography using both biplane static coronary angiography (BiP) and RA techniques at the Children's Hospital of Wisconsin from February 2009 to September 2010. Demographic and procedure data were collected from each procedure and analyzed for significance utilizing a Wilcoxon rank sum test. No significant demographic or procedural differences between the BiP and the RA procedures were noted. Specific measures of radiation dose including fluoroscopy time and dose area product were similar among the imaging techniques. The findings show that RA can be performed safely and reproducibly in pediatric heart transplant recipients. Compared with standard BiP, RA does not increase radiation exposure or contrast use and in our experience has provided superior angiographic imaging for the evaluation of graft coronary vasculopathy. PMID:22956061

  7. 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

  8. Random bistochastic matrices

    NASA Astrophysics Data System (ADS)

    Cappellini, Valerio; Sommers, Hans-Jürgen; Bruzda, Wojciech; Życzkowski, Karol

    2009-09-01

    Ensembles of random stochastic and bistochastic matrices are investigated. While all columns of a random stochastic matrix can be chosen independently, the rows and columns of a bistochastic matrix have to be correlated. We evaluate the probability measure induced into the Birkhoff polytope of bistochastic matrices by applying the Sinkhorn algorithm to a given ensemble of random stochastic matrices. For matrices of order N = 2 we derive explicit formulae for the probability distributions induced by random stochastic matrices with columns distributed according to the Dirichlet distribution. For arbitrary N we construct an initial ensemble of stochastic matrices which allows one to generate random bistochastic matrices according to a distribution locally flat at the center of the Birkhoff polytope. The value of the probability density at this point enables us to obtain an estimation of the volume of the Birkhoff polytope, consistent with recent asymptotic results.

  9. Generating random density matrices

    NASA Astrophysics Data System (ADS)

    Życzkowski, Karol; Penson, Karol A.; Nechita, Ion; Collins, Benoît

    2011-06-01

    We study various methods to generate ensembles of random density matrices of a fixed size N, obtained by partial trace of pure states on composite systems. Structured ensembles of random pure states, invariant with respect to local unitary transformations are introduced. To analyze statistical properties of quantum entanglement in bi-partite systems we analyze the distribution of Schmidt coefficients of random pure states. Such a distribution is derived in the case of a superposition of k random maximally entangled states. For another ensemble, obtained by performing selective measurements in a maximally entangled basis on a multi-partite system, we show that this distribution is given by the Fuss-Catalan law and find the average entanglement entropy. A more general class of structured ensembles proposed, containing also the case of Bures, forms an extension of the standard ensemble of structureless random pure states, described asymptotically, as N → ∞, by the Marchenko-Pastur distribution.

  10. Randomness: Quantum versus classical

    NASA Astrophysics Data System (ADS)

    Khrennikov, Andrei

    2016-05-01

    Recent tremendous development of quantum information theory has led to a number of quantum technological projects, e.g. quantum random generators. This development had stimulated a new wave of interest in quantum foundations. One of the most intriguing problems of quantum foundations is the elaboration of a consistent and commonly accepted interpretation of a quantum state. Closely related problem is the clarification of the notion of quantum randomness and its interrelation with classical randomness. In this short review, we shall discuss basics of classical theory of randomness (which by itself is very complex and characterized by diversity of approaches) and compare it with irreducible quantum randomness. We also discuss briefly “digital philosophy”, its role in physics (classical and quantum) and its coupling to the information interpretation of quantum mechanics (QM).

  11. Quantum random number generator

    DOEpatents

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  12. The Prognosis of Patients With Nonobstructive Coronary Artery Disease Versus Normal Arteries Determined by Invasive Coronary Angiography or Computed Tomography Coronary Angiography: A Systematic Review.

    PubMed

    Huang, Fang-Yang; Huang, Bao-Tao; Lv, Wen-Yu; Liu, Wei; Peng, Yong; Xia, Tian-Li; Wang, Peng-Ju; Zuo, Zhi-Liang; Liu, Rui-Shuang; Zhang, Chen; Gui, Yi-Yue; Liao, Yan-Biao; Chen, Mao; Zhu, Ye

    2016-03-01

    Limited data exist regarding the outcomes of patients with nonobstructive coronary artery disease (CAD) detected by computed tomography coronary angiography (CTCA) or invasive coronary angiography (ICA). Our aim was to compare the prognosis of patients with nonobstructive coronary artery plaques with that of patients with entirely normal arteries. The MEDLINE, Cochrane Library, and Embase databases were searched. Studies comparing the prognosis of individuals with nonobstructive CAD versus normal coronary arteries detected by CTCA or ICA were included. The primary outcome was major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, hospitalization due to unstable angina or revascularization. A fixed effects model was chosen to pool the estimates of odds ratios (ORs). Forty-eight studies with 64,905 individuals met the inclusion criteria. Patients in the nonobstructive CAD arm had a significantly higher risk of MACE compared to their counterparts in the normal artery arm (pooled OR, 3.17, 95% confidence interval, 2.77-3.63). When excluding revascularization as an endpoint, hard cardiac composite outcomes were also more frequent among patients with nonobstructive CAD (pooled OR, 2.10; 95%CI, 1.79-2.45). All subgroups (age, sex, follow-up duration, different outcomes, diagnostic modality, and CAD risk factor) consistently showed a poorer prognosis with nonobstructive CAD than with normal arteries. When dividing the studies into a CTCA and ICA group for further analysis based on the indications for diagnostic tests, we also found nonobstructive CAD to be associated with a higher risk of MACE in both stable and acute chest pain. Patients with nonobstructive CAD had a poorer prognosis compared with their counterparts with normal arteries.

  13. 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.

  14. The Prognosis of Patients With Nonobstructive Coronary Artery Disease Versus Normal Arteries Determined by Invasive Coronary Angiography or Computed Tomography Coronary Angiography

    PubMed Central

    Huang, Fang-Yang; Huang, Bao-Tao; Lv, Wen-Yu; Liu, Wei; Peng, Yong; Xia, Tian-Li; Wang, Peng-Ju; Zuo, Zhi-Liang; Liu, Rui-Shuang; Zhang, Chen; Gui, Yi-Yue; Liao, Yan-Biao; Chen, Mao; Zhu, Ye

    2016-01-01

    Abstract Limited data exist regarding the outcomes of patients with nonobstructive coronary artery disease (CAD) detected by computed tomography coronary angiography (CTCA) or invasive coronary angiography (ICA). Our aim was to compare the prognosis of patients with nonobstructive coronary artery plaques with that of patients with entirely normal arteries. The MEDLINE, Cochrane Library, and Embase databases were searched. Studies comparing the prognosis of individuals with nonobstructive CAD versus normal coronary arteries detected by CTCA or ICA were included. The primary outcome was major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, hospitalization due to unstable angina or revascularization. A fixed effects model was chosen to pool the estimates of odds ratios (ORs). Forty-eight studies with 64,905 individuals met the inclusion criteria. Patients in the nonobstructive CAD arm had a significantly higher risk of MACE compared to their counterparts in the normal artery arm (pooled OR, 3.17, 95% confidence interval, 2.77–3.63). When excluding revascularization as an endpoint, hard cardiac composite outcomes were also more frequent among patients with nonobstructive CAD (pooled OR, 2.10; 95%CI, 1.79–2.45). All subgroups (age, sex, follow-up duration, different outcomes, diagnostic modality, and CAD risk factor) consistently showed a poorer prognosis with nonobstructive CAD than with normal arteries. When dividing the studies into a CTCA and ICA group for further analysis based on the indications for diagnostic tests, we also found nonobstructive CAD to be associated with a higher risk of MACE in both stable and acute chest pain. Patients with nonobstructive CAD had a poorer prognosis compared with their counterparts with normal arteries. PMID:26986161

  15. Three-dimensional time-of-flight MR angiography for evaluation of intracranial aneurysms after endosaccular packing with Guglielmi detachable coils: comparison with 3D digital subtraction angiography.

    PubMed

    Okahara, Mika; Kiyosue, Hiro; Hori, Yuzo; Yamashita, Masanori; Nagatomi, Hirofumi; Mori, Hiromu

    2004-07-01

    The sensitivities and specificities of three-dimensional time-of-flight MR angiography (3D-TOF MRA) and 3D digital subtraction angiography (3D-DSA) were compared for evaluation of cerebral aneurysms after endosaccular packing with Guglielmi detachable coils (GDCs). Thirty-three patients with 33 aneurysms were included in this prospective study. 3D-TOF MRA and 3D-DSA were performed in the same week on all patients. Maximal intensity projection (MIP) and 3D reconstructed MRA images were compared with 3D-DSA images. The diameters of residual/recurrent aneurysms detected on 3D-DSA were calculated on a workstation. In 3 (9%) of 33 aneurysms, 3D-TOF MRA did not provide reliable information due to significant susceptibility artifacts on MRA. The sensitivity and specificity rates of MRA were 72.7 and 90.9%, respectively, for the diagnosis of residual/recurrent aneurysm. The diameters of residual/recurrent aneurysms that could not be detected by MRA were significantly smaller than those of detected aneurysms (mean 1.1 vs mean 2.3 mm). In one aneurysm of the anterior communicating artery (ACoA), the relationship between the residual aneurysm and the ACoA was more evident on MRA than DSA images. MRA can detect the recurrent/residual lumen of aneurysms treated with GDCs of up to at least 1.8 mm in diameter. 3D-TOF MRA is useful for follow-up of intracranial aneurysms treated with GDCs, and could partly replace DSA.

  16. The Prognosis of Patients With Nonobstructive Coronary Artery Disease Versus Normal Arteries Determined by Invasive Coronary Angiography or Computed Tomography Coronary Angiography: A Systematic Review.

    PubMed

    Huang, Fang-Yang; Huang, Bao-Tao; Lv, Wen-Yu; Liu, Wei; Peng, Yong; Xia, Tian-Li; Wang, Peng-Ju; Zuo, Zhi-Liang; Liu, Rui-Shuang; Zhang, Chen; Gui, Yi-Yue; Liao, Yan-Biao; Chen, Mao; Zhu, Ye

    2016-03-01

    Limited data exist regarding the outcomes of patients with nonobstructive coronary artery disease (CAD) detected by computed tomography coronary angiography (CTCA) or invasive coronary angiography (ICA). Our aim was to compare the prognosis of patients with nonobstructive coronary artery plaques with that of patients with entirely normal arteries. The MEDLINE, Cochrane Library, and Embase databases were searched. Studies comparing the prognosis of individuals with nonobstructive CAD versus normal coronary arteries detected by CTCA or ICA were included. The primary outcome was major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, hospitalization due to unstable angina or revascularization. A fixed effects model was chosen to pool the estimates of odds ratios (ORs). Forty-eight studies with 64,905 individuals met the inclusion criteria. Patients in the nonobstructive CAD arm had a significantly higher risk of MACE compared to their counterparts in the normal artery arm (pooled OR, 3.17, 95% confidence interval, 2.77-3.63). When excluding revascularization as an endpoint, hard cardiac composite outcomes were also more frequent among patients with nonobstructive CAD (pooled OR, 2.10; 95%CI, 1.79-2.45). All subgroups (age, sex, follow-up duration, different outcomes, diagnostic modality, and CAD risk factor) consistently showed a poorer prognosis with nonobstructive CAD than with normal arteries. When dividing the studies into a CTCA and ICA group for further analysis based on the indications for diagnostic tests, we also found nonobstructive CAD to be associated with a higher risk of MACE in both stable and acute chest pain. Patients with nonobstructive CAD had a poorer prognosis compared with their counterparts with normal arteries. PMID:26986161

  17. Autonomous Byte Stream Randomizer

    NASA Technical Reports Server (NTRS)

    Paloulian, George K.; Woo, Simon S.; Chow, Edward T.

    2013-01-01

    Net-centric networking environments are often faced with limited resources and must utilize bandwidth as efficiently as possible. In networking environments that span wide areas, the data transmission has to be efficient without any redundant or exuberant metadata. The Autonomous Byte Stream Randomizer software provides an extra level of security on top of existing data encryption methods. Randomizing the data s byte stream adds an extra layer to existing data protection methods, thus making it harder for an attacker to decrypt protected data. Based on a generated crypto-graphically secure random seed, a random sequence of numbers is used to intelligently and efficiently swap the organization of bytes in data using the unbiased and memory-efficient in-place Fisher-Yates shuffle method. Swapping bytes and reorganizing the crucial structure of the byte data renders the data file unreadable and leaves the data in a deconstructed state. This deconstruction adds an extra level of security requiring the byte stream to be reconstructed with the random seed in order to be readable. Once the data byte stream has been randomized, the software enables the data to be distributed to N nodes in an environment. Each piece of the data in randomized and distributed form is a separate entity unreadable on its own right, but when combined with all N pieces, is able to be reconstructed back to one. Reconstruction requires possession of the key used for randomizing the bytes, leading to the generation of the same cryptographically secure random sequence of numbers used to randomize the data. This software is a cornerstone capability possessing the ability to generate the same cryptographically secure sequence on different machines and time intervals, thus allowing this software to be used more heavily in net-centric environments where data transfer bandwidth is limited.

  18. Preoperative evaluation value of aortic arch lesions by multidetector computed tomography angiography in type A aortic dissection.

    PubMed

    Huang, Fang; Chen, Qiang; Lai, Qing-Quan; Huang, Wen-Han; Wu, Hong; Li, Wei-Cheng

    2016-09-01

    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

  19. 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

  20. Randomness for Free

    NASA Astrophysics Data System (ADS)

    Chatterjee, Krishnendu; Doyen, Laurent; Gimbert, Hugo; Henzinger, Thomas A.

    We consider two-player zero-sum games on graphs. These games can be classified on the basis of the information of the players and on the mode of interaction between them. On the basis of information the classification is as follows: (a) partial-observation (both players have partial view of the game); (b) one-sided complete-observation (one player has complete observation); and (c) complete-observation (both players have complete view of the game). On the basis of mode of interaction we have the following classification: (a) concurrent (players interact simultaneously); and (b) turn-based (players interact in turn). The two sources of randomness in these games are randomness in transition function and randomness in strategies. In general, randomized strategies are more powerful than deterministic strategies, and randomness in transitions gives more general classes of games. We present a complete characterization for the classes of games where randomness is not helpful in: (a) the transition function (probabilistic transition can be simulated by deterministic transition); and (b) strategies (pure strategies are as powerful as randomized strategies). As consequence of our characterization we obtain new undecidability results for these games.

  1. 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

  2. Radiation Dose to the Thyroid and Gonads in Patients Undergoing Cardiac CT Angiography

    PubMed Central

    Behroozi, Hamid; Davoodi, Mohammad; Aghasi, Shahriar

    2015-01-01

    Background: The present data show a global increase in the rate of cardiovascular disease. Cardiac CT angiography has developed as a fast and non-invasive cardiac imaging modality following the introduction of multi-slice computed tomogaraphy. Objectives: The aim of this study was to measure the radiation dose to the thyroid and pelvis regions in patients undergoing cardiac CT angiography using the Care Dose 4D method of 64-slice scanner. Patients and Methods: Eighty-one patients (41 males and 40 females) who were diagnosed with suspected coronary artery disease and were referred to Golestan Hospital, Imaging Department were recruited. Inclusion criteria were based on the protocol of multi-slice CT coronary angiography. The radiation dose to the thyroid and pelvis regions was measured using thermo luminescent dosimeters (TLDs). Results: The mean radiation dose to the thyroid in male and female subjects was 0.32 mSv and 0.41 mSv, respectively (P = 0.032) (total mean, 0.36 mSv). The mean radiation dose to the pelvis in male and female subjects was 81 μSv and 112 μSv, respectively (P = 0.026) (total mean, 96.5 μSv), Conclusions: The total mean radiation dose to the thyroid and gonads was 0.36 mSv, and 96.5 μSv, respectively for the subjects. These values were high for one organ in a single study. Gender can affect the radiation dose to the thyroid and gonads. This can be attributed to the anatomical characteristic differences of the male and female subjects. PMID:26060556

  3. Diagnostic Utility of Three-Dimensional Rotational Angiography in Congenital Cardiac Catheterization.

    PubMed

    Aldoss, Osamah; Fonseca, Brian M; Truong, Uyen T; Bracken, John; Darst, Jeffrey R; Guo, Ruixin; Jones, Tamekia L; Fagan, Thomas E

    2016-10-01

    We evaluated the diagnostic utility of the three modalities of three-dimensional rotational angiography (3DRA): rotational angiography (RA), multiplanar reformat (MPR) and three-dimensional angiographic reconstruction (3D-R) in pediatric cardiac catheterization. The 3DRA studies were classified by anatomy of interest based on our injection protocol: pulmonary arteries (PA), aorta, cavopulmonary connection (CPC), and others. Retrospective review of 3DRA images by two reviewers for each modality was conducted with grading as inferior, similar, or superior in comparison with the diagnostic quality of fixed-plane angiography (FPA). The percentages of grades for each modality were averaged. Weighted kappa statistic was used to evaluate inter-rater reliability. In total, 114 3DRA studies were performed on 87 patients between August 2010 and March 2012. Median age was 2.7 years (1 day-48.4 years) and median weight 12.1 kg (3.6-106.5 kg). For RA: 79.4 % of the studies were of diagnostic quality and 52.2 % were superior; 3D-R: 82 % were of diagnostic quality and 65.8 % were superior; and MPR: 83.5 % were of diagnostic quality and 63 % were superior. Overall 3DRA technologies (RA, 3D-R, MPR) were of diagnostic quality or better in 111/114 (97.4 %) studies and 103/114 (90.4 %) were judged superior. Most common reasons for inferior grading were limited opacification and metallic artifact. In pediatric cardiac catheterization, 3DRA imaging was of diagnostic quality and frequently provided additional clinically relevant data when compared to FPA. PMID:27278632

  4. Contrast-enhanced MR angiography utilizing parallel acquisition techniques in renal artery stenosis detection.

    PubMed

    Slanina, Martin; Zizka, Jan; Klzo, Ludovít; Lojík, Miroslav

    2010-07-01

    Significant renal artery stenosis (RAS) is a potentially curable cause of renovascular hypertension and/or renal impairment. It is caused by either atherosclerosis or fibromuscular dysplasia. Correct and timely diagnosis remains a diagnostic challenge. MR angiography (MRA) as a minimally invasive method seems to be suitable for RAS detection, however, its diagnostic value widely differs in the literature (sensitivity 62-100% and specificity 75-100%). The aim of our prospective study was to compare the diagnostic value of contrast-enhanced MRA utilizing parallel acquisition techniques in the detection of significant RAS with digital subtraction angiography (DSA). A total of 78 hypertensive subjects with suspected renal artery stenosis were examined on a 1.5 Tesla MR system using a body array coil. Bolus tracking was used to monitor the arrival of contrast agent to the abdominal aorta. The MRA sequence parameters were as follows: TR 3.7 ms; TE 1.2 ms; flip angle 25 degrees; acquisition time 18s; voxel size 1.1 mm x1.0 mm x 1.1 mm; centric k-space sampling; parallel acquisition technique with acceleration factor of 2 (GRAPPA). Renal artery stenosis of 60% and more was considered hemodynamically significant. The results of MRA were compared to digital subtraction angiography serving as a standard of reference. Sensitivity and specificity of MRA in the detection of hemodynamically significant renal artery stenosis were 90% and 96%, respectively. Prevalence of RAS was 39% in our study population. Contrast-enhanced MRA with high spatial resolution offers sufficient sensitivity and specificity for screening of RAS. PMID:19671492

  5. Staff Radiation Doses in a Real-Time Display Inside the Angiography Room

    SciTech Connect

    Sanchez, Roberto Vano, E.; Fernandez, J. M.; Gallego, J. J.

    2010-12-15

    MethodsThe evaluation of a new occupational Dose Aware System (DAS) showing staff radiation doses in real time has been carried out in several angiography rooms in our hospital. The system uses electronic solid-state detectors with high-capacity memory storage. Every second, it archives the dose and dose rate measured and is wirelessly linked to a base-station screen mounted close to the diagnostic monitors. An easy transfer of the values to a data sheet permits further analysis of the scatter dose profile measured during the procedure, compares it with patient doses, and seeks to find the most effective actions to reduce operator exposure to radiation.ResultsThe cumulative occupational doses measured per procedure (shoulder-over lead apron) ranged from 0.6 to 350 {mu}Sv when the ceiling-suspended screen was used, and DSA (Digital Subtraction Acquisition) runs were acquired while the personnel left the angiography room. When the suspended screen was not used and radiologists remained inside the angiography room during DSA acquisitions, the dose rates registered at the operator's position reached up to 1-5 mSv/h during fluoroscopy and 12-235 mSv/h during DSA acquisitions. In such case, the cumulative scatter dose could be more than 3 mSv per procedure.ConclusionReal-time display of doses to staff members warns interventionists whenever the scatter dose rates are too high or the radiation protection tools are not being properly used, providing an opportunity to improve personal protection accordingly.

  6. 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.

  7. Effective dose analysis of three-dimensional rotational angiography during catheter ablation procedures

    NASA Astrophysics Data System (ADS)

    Wielandts, J.-Y.; Smans, K.; Ector, J.; De Buck, S.; Heidbüchel, H.; Bosmans, H.

    2010-02-01

    There is increasing use of three-dimensional rotational angiography (3DRA) during cardiac ablation procedures. As compared with 2D angiography, a large series of images are acquired, creating the potential for high radiation doses. The aim of the present study was to quantify patient-specific effective doses. In this study, we developed a computer model to accurately calculate organ doses and the effective dose incurred during 3DRA image acquisition. The computer model simulates the exposure geometry and uses the actual exposure parameters, including the variation in tube voltage and current that is realized through the automatic exposure control (AEC). We performed 3DRA dose calculations in 42 patients referred for ablation on the Siemens Axiom Artis DynaCT system (Erlangen, Germany). Organ doses and effective dose were calculated separately for all projections in the course of the C-arm rotation. The influence of patient body mass index (BMI), dose-area product (DAP), collimation and dose per frame (DPF) rate setting on the calculated doses was also analysed. The effective dose was found to be 5.5 ± 1.4 mSv according to ICRP 60 and 6.6 ± 1.8 mSv according to ICRP 103. Effective dose showed an inversely proportional relationship to BMI, while DAP was nearly BMI independent. No simple conversion coefficient between DAP and effective dose could be derived. DPF reduction did not result in a proportional effective dose decrease. These paradoxical findings were explained by the settings of the AEC and the limitations of the x-ray tube. Collimation reduced the effective dose by more than 20%. Three-dimensional rotational angiography is associated with a definite but acceptable radiation dose that can be calculated for all patients separately. Their BMI is a predictor of the effective dose. The dose reduction achieved with collimation suggests that its use is imperative during the 3DRA procedure.

  8. Comparative Efficacy of Transradial Versus Transfemoral Approach for Coronary Angiography and Percutaneous Coronary Intervention.

    PubMed

    Schussler, Jeffrey M; Vasudevan, Anupama; von Bose, Liana J; Won, Jane I; McCullough, Peter A

    2016-08-15

    Transradial artery (TRA) approach is associated with fewer vascular complications and reduced mortality in patients at high risk compared with transfemoral approach (TFA). The objective of our study was to compare the characteristics and outcomes of patients who had coronary angiography by TRA and TFA over the course of hospital implementation of this approach. We included 12,928 patients from Baylor University Medical Center and Baylor Heart and Vascular Hospital, Dallas, Texas, who underwent a coronary angiography from January 2008 to March 2015. To control for selection bias and the learning curve, a nested matched study design was used for patients with percutaneous coronary intervention (PCI) with TRA patients matched with TFA by age (±2 years) and calendar year of the procedure in a ratio of 1:3. TRA for PCI increased from nearly 0% in 2008 to 9% in 2014. Including patients from 2011 to 2015 for the analysis, patients with TFA were older (65 ± 12 vs 64 ± 11) and had lower mean body mass index (30 ± 7 vs 33 ± 9 kg/m(2)) than patients with TRA. Patients with TRA had less bleeding, dialysis, pseudoaneurysm, and access site hematomas than the patients with TRA (0.7% vs 0%; p = 0.02). By a conditional logistic regression, we observed fewer complications, readmissions, and in-hospital deaths among TRA patients than the matched TFA patients. In conclusion, patients undergoing angiography with/without PCI through TRA had fewer complications, readmissions, and a shorter length of hospital stay after procedure versus TFA at our hospital. PMID:27378143

  9. Solid-state fluoroscopic imager for high-resolution angiography: Parallel-cascaded linear systems analysis

    PubMed Central

    Vedantham, Srinivasan; Karellas, Andrew; Suryanarayanan, Sankararaman

    2008-01-01

    Cascaded linear systems based modeling techniques have been used in the past to predict important system parameters that have a direct impact on image quality. Such models are also useful in optimizing system parameters to improve image quality. In this work, detailed analysis of a solid-state fluoroscopic imaging system intended for high-resolution angiography is presented with the use of such a model. The imaging system analyzed through this model uses four 8×8 cm three-side buttable interlined charge-coupled devices (CCDs) specifically designed for high-resolution angiography and tiled in a seamless fashion to achieve a field of view (FOV) of 16×16 cm. Larger FOVs can be achieved by tiling more CCDs in a similar manner. The system employs a CsI:Tl scintillator coupled to the CCDs by straight (nontapering) fiberoptics and can potentially be operated in 78, 156, or 234 μm pixel pitch modes. The system parameters analyzed through this model include presampling modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE). The results of the simulations performed indicate that DQE(0) in excess of 0.6 is achievable, with the imager operating at 156 μm pixel pitch, 30 frames/s, and employing a 450-μm-thick CsI:Tl scintillator, even at a low fluoroscopic exposure rate of 1 μR/frame. Further, at a nominal fluoroscopic exposure rate of 2.5 μR/frame there was no noticeable degradation of the DQE even at the 78 μm pixel pitch mode suggesting that it is feasible to perform high-resolution angiography hitherto unattainable in clinical practice. PMID:15191318

  10. 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

  11. Assessment of zebrafish cardiac performance using Doppler echocardiography and power angiography.

    PubMed

    Ho, Yi-Lwun; Shau, Yio-Wha; Tsai, Huai-Jen; Lin, Lung-Chun; Huang, Por-Jau; Hsieh, Fon-Jou

    2002-09-01

    The zebrafish (Danio rerio) has become a new animal model for cardiac researches. Although it is equipped with a prototypical vertebrate heart, the zebrafish studies for cardiac mutations and genetic control of development can reveal some hints for solving human problems. Despite the simplicity of the zebrafish heart, the objective parameters of cardiac performance are not easily available, except for the morphological description, due to its small size. Because the four components (sinus venosus, atrium, ventricle and bulbus arteriosus) of the zebrafish heart are connected in series, we studied it by applying ultrasonic imaging methods for the vascular system. A total of 20 fishes that were ages of 3 to 4 months were studied. Their mean body weight and height were 562 +/- 173 mg and 4.6 +/- 0.7 cm, respectively. Power angiography and routine Doppler echocardiography were used to evaluate the cardiac performance of zebrafish at 25 degrees C and 15 degrees C. The zebrafish hearts could be easily identified with color Doppler (8.5 MHz) or power angiography (7 MHz). The ventricular filling flow contained two components (E and A-flow). The E-flow velocities were lower than the A-flow velocities at both 25 and 15 degrees C. The cycle length was prolonged (p < 0.05) and the velocities of ventricular filling and bulbus arteriosus decreased significantly at 15 degrees C (p < 0.05). A significant decrease in early diastolic deceleration slope and significant prolongation in early diastolic and late-diastolic deceleration times were found at a lower temperature (15 degrees C). The acceleration:deceleration ratio for early and late diastole also showed a significant difference at 15 degrees C. In conclusion, the cardiac performance of the zebrafish could be approached using commercially available clinical instruments equipped with Doppler echocardiography and power angiography.

  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. Computer-aided CT coronary artery stenosis detection: comparison with human reading and quantitative coronary angiography.

    PubMed

    Rief, Matthias; Kranz, Anisha; Hartmann, Lisa; Roehle, Robert; Laule, Michael; Dewey, Marc

    2014-12-01

    To evaluate computer-aided stenosis detection for computed tomography coronary angiography (CTA) in comparison with human reading and conventional coronary angiography (CCA) as the reference standard. 50 patients underwent CTA and CCA and out of these 44 were evaluable for computer-aided stenosis detection. The diagnostic performance of the software and of human reading were compared and quantitative coronary angiography (QCA) served as the reference standard for the detection of significant stenosis (>50 %). Overall, three readers with high (reader 1), intermediate (reader 2) and low (reader 3) experience in cardiac CT imaging performed the manual CTA evaluation on a commercially available workstation, whereas the automated software processed the datasets without any human interaction. The prevalence of coronary artery disease was 41 % (18/44) and QCA indicated significant stenosis (>50 %) in 33 coronary vessels. The automated software accurately diagnosed 18 individuals with significant coronary artery disease (CAD), and correctly ruled out CAD in 10 patients. In summary the sensitivity of computer-aided detection was 100 %/94 % (per-patient/per-vessel) and the specificity was 38 %/70 %, the positive predictive value (PPV) was 53 %/42 % and the negative predictive value (NPV) was 100 %/98 %. In comparison, reader 1-3 showed per-patient sensitivities of 100/94/89 %, specificities of 73/69/50 %, PPVs of 72/68/55 % and NPVs of 100/95/87 %. Computer-aided detection yields a high NPV that is comparable to more experienced human readers. However, PPV is rather low and in the range of an unexperienced reader.

  14. Radiation exposure during coronary angiography via transradial or transfemoral approaches when performed by experienced operators

    PubMed Central

    Shah, Binita; Bangalore, Sripal; Feit, Frederick; Fernandez, Gregory; Coppola, John; Attubato, Michael J.; Slater, James

    2013-01-01

    Background Studies demonstrate an increase in radiation exposure with transradial approach (TRA) when compared with transfemoral approach (TFA) for coronary angiography. Given the learning curve associated with TRA, it is not known if this increased radiation exposure to patients is seen when procedures are performed by experienced operators. Methods We retrospectively evaluated 1,696 patients who underwent coronary angiography with or without percutaneous coronary intervention (PCI) by experienced operators at a tertiary center from October 2010 to June 2011. Experienced operators were defined as those that perform >75 PCIs/year with >95% of cases performed using the TRA or TFA approach for ≥5 years. The outcomes of interest were dose area product (DAP) and fluoroscopy time (FT). Results Of the 1,696 patients, 1,382 (81.5%) were performed by experienced femoral operators using TFA and 314 (18.5%) were performed by experienced radial operators using TRA. Most of these cases (65.4%) were diagnostic only (870 TFA and 240 TRA) with both DAP (6040 [3210–8786] vs 5019 [3377–6869] μGy·m2, P = .003] and FT [6.2 [4.0–10.3] vs 3.3 [2.6–5.0] minutes, P < .001) significantly higher using TRA versus TFA. For procedures involving PCI, despite similar baseline patient, procedural and lesion characteristics, DAP and FT remained significantly higher using TRA versus TFA (19,649 [11,996–25,929] vs 15,395 [10,078–21,617] μGy·m2, P = .02 and 22.1 [13.3–31.0] vs. 13.8 [9.8–20.3] minutes, P < .001). Conclusions In a contemporary cohort of patients undergoing coronary angiography by experienced operators, TRA was associated with higher radiation exposure when compared with TFA. PMID:23453094

  15. Coronary lesion complexity assessed by SYNTAX score in 256-slice dual-source MDCT angiography

    PubMed Central

    Yüceler, Zeyneb; Kantarcı, Mecit; Tanboğa, İbrahim Halil; Sade, Recep; Kızrak, Yeşim; Pirimoğlu, Berhan; Bayraktutan, Ümmügülsüm; Oğul, Hayri; Aksakal, Enbiya

    2016-01-01

    PURPOSE The SYNTAX Score (SS) has an important role in grading the complexity of coronary artery disease (CAD) in patients undergoing revascularization. Noninvasive determination of SS prior to invasive coronary angiography (ICA) might optimize patient management. We aimed to evaluate the agreement between ICA and multidetector computed tomography (MDCT) while testing the diagnostic effectiveness of SS-MDCT. METHODS Our study included 108 consecutive patients who underwent both MDCT angiography with a 256-slice dual-source MDCT system and ICA within 14±3 days. SS was calculated for both ICA and MDCT coronary angiography. Spearman’s rank correlation coefficient was used to evaluate the association of SS-MDCT with SS-ICA, and Bland-Altman analysis was performed. RESULTS The degree of agreement between SS-ICA and SS-MDCT was moderate. The mean SS-MDCT was 14.5, whereas the mean SS-ICA was 15.9. After dividing SS into three groups (high [≥33], intermediate [23–32], and low [≤22] subgroups), agreement analysis was repeated. There was a significant correlation between SS-MDCT and SS-ICA in the low SS group (r=0.63, P = 0.043) but no significant correlation in the high SS group (r=0.036, P = 0.677). The inter-test agreement analysis showed at least moderate agreement, whereas thrombotic lesions and the type of bifurcation lesion showed fair agreement. CONCLUSION The calculation of SS-MDCT by adapting SS-ICA parameters achieved nearly the same degree of precision as SS-ICA and was better than SS-ICA, especially in the low SS group. PMID:27328718

  16. Selecting people randomly.

    PubMed

    Broome, John

    1984-10-01

    This article considers what justification can be found for selecting randomly and in what circumstances it applies, including that of selecting patients to be treated by a scarce medical procedure. The author demonstrates that balancing the merits of fairness, common good, equal rights, and equal chance as they apply in various situations frequently leads to the conclusion that random selection may not be the most appropriate mode of selection. Broome acknowledges that, in the end, we may be forced to conclude that the only merit of random selection is the political one of guarding against partiality and oppression.

  17. Glomus tumour of the hallux: diagnosis by Doppler-shift ultrasound and digital subtraction angiography.

    PubMed Central

    Kreel, L.; Thornton, A.; Pardy, B. J.

    1986-01-01

    A case is presented of a glomangioma with typical history and clinical findings, proven by operation and histology. Unique radiographic features are demonstrated including visualization of the tumour on a soft tissue radiograph and associated hyperaemic bone changes, continuous wave Doppler results indicating hyperaemia and an arterio-venous malformation, and the clear demonstration of the tumour in both frontal and lateral views was possible by intra-arterial digital subtraction angiography (DSA) under local anaesthesia. Fibrous dysplasia of a femur was an incidental finding. Images Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 PMID:3018711

  18. 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

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

    SciTech Connect

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

    2006-05-15

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

  20. Imaging Quality Evaluation of Low Tube Voltage Coronary CT Angiography Using Low Concentration Contrast Medium

    PubMed Central

    Zhang, Zaixian; Wang, Qingguo; Zheng, Linfeng; Feng, Yan; Zhou, Zhiguo; Zhang, Guixiang; Li, Kangan

    2015-01-01

    Purpose To compare the image quality of prospectively ECG-gated low voltage coronary computed tomography angiography (CTA) with an administration of low concentration contrast medium. Method and Materials A total of 101 patients, each with a heart rate below 65 beats per minute (BPM), underwent a prospectively ECG-gated axial scan in CT coronary angiography on a 64-slice CT scanner. All patients were allocated in three groups (group A: n=31, 80kVp, 300 mgI/ml; group B: n=34, 100kVp, 300 mgI/ml; group C: n=36, 120kVp, 370 mgI/ml). The CT attenuation values of aortic root (AR), left main coronary artery (LMA), right main coronary artery (RMA) and chest subcutaneous fat tissue were measured. The contrast-to-noise ratio (CNR) of AR, LMA and RMA were calculated according to the formulas below. The values of computed tomography dose index (CTDI) and dose-length product (DLP) were recorded. Image quality was assessed on a 5-point scale. The results were compared using the one-way ANOVA and rank sum tests. Results The values of CNR and SNR for vessels in group A and group B were not significantly different from group C (each p > 0.05). The effective radiation dose in group A (1.51±0.70 mSv) and group B (2.59±1.24 mSv) were both lower than group C (4.92±2.82 mSv) (each p < 0.05). There was no significant difference among the image quality scores of group A (4.10±0.41), group B (3.90±0.48) and group C (4.04±0.36) (each P > 0.05). Conclusion Low tube voltage coronary CT angiography using low concentration contrast medium does not affect the imaging quality for assessing the coronary arteries compared with high voltage coronary CT angiography using high concentration contrast medium. Meanwhile low concentration contrast medium allowed 47-69% of radiation dose reduction. PMID:25811785

  1. New Image Reconstruction Methods for Accelerated Quantitative Parameter Mapping and Magnetic Resonance Angiography

    NASA Astrophysics Data System (ADS)

    Velikina, J. V.; Samsonov, A. A.

    2016-02-01

    Advanced MRI techniques often require sampling in additional (non-spatial) dimensions such as time or parametric dimensions, which significantly elongate scan time. Our purpose was to develop novel iterative image reconstruction methods to reduce amount of acquired data in such applications using prior knowledge about signal in the extra dimensions. The efforts have been made to accelerate two applications, namely, time resolved contrast enhanced MR angiography and T1 mapping. Our result demonstrate that significant acceleration (up to 27x times) may be achieved using our proposed iterative reconstruction techniques.

  2. Coronary computed tomographic angiography in clinical practice: state of the art.

    PubMed

    Meinel, Felix G; Bayer, Richard R; Zwerner, Peter L; De Cecco, Carlo Nicola; Schoepf, U Joseph; Bamberg, Fabian

    2015-03-01

    In patients with stable chest pain, coronary CT angiography (CCTA) has demonstrated high accuracy in excluding coronary artery disease and CCTA findings carry prognostic significance for the occurrence of future cardiovascular events. Increasingly, CCTA has been adopted as a triage tool in patients with acute chest pain. In specific clinical scenarios, CCTA further represents a useful tool to exclude an ischemic etiology in patients with cardiac arrhythmias or newly diagnosed heart failure. Several novel techniques are currently being investigated which may extend the ability of CCTA to characterize and quantify coronary artery plaque and assess the hemodynamic significance of stenosis. PMID:25726994

  3. 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.

  4. Double Origin of the Posterior Inferior Cerebellar Artery Diagnosed by MR Angiography

    PubMed Central

    Saito, Naoko; Ishihara, Shoichiro

    2015-01-01

    The posterior inferior cerebellar artery (PICA) frequently arises from the fenestrated segment of the intracranial vertebral artery (VA), and this common variation can be misinterpreted as or confused with a PICA of double origin. Rarely, a PICA of true double origin occurs when two branches of the PICA arise separately from the intracranial VA and fuse to form an arterial ring. We discovered this rare variation incidentally while interpreting images of magnetic resonance (MR) angiography. This is the first report of MR angiographic findings of this rare variation. PMID:25923681

  5. Inferior vena cava leiomyosarcoma confirmed by catheter suction biopsy during digital subtraction angiography.

    PubMed

    Wei, Ning; Xu, Xiang-Dong; Xu, Hao; Zu, Mao-Heng

    2014-01-01

    Leiomyosarcoma of vascular origin is a rare disease and most cases arise in the inferior vena cava. Inferior vena cava leiomyosarcoma (IVCLMS) usually presents in females in their sixth decade of life. The clinical symptoms are often non-specific and the diagnosis is often delayed. Current imaging techniques can accurately differentiate inferior vena cava neoplasms from other non-neoplastic lesions. However, definitive diagnosis of IVCLMS needs histologic evidence. We report a case of IVCLMS in a 61-year old Chinese woman. This is the first IVCLMS case confirmed by catheter suction biopsy during digital subtraction angiography. PMID:25232438

  6. Transient Global Amnesia After Cerebral Angiography With Iomeprol: A Case Report.

    PubMed

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

    2016-05-01

    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, T2/FLAIR

  7. 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.].

  8. Pulsed-injection method for blood flow velocity measurement in intraarterial digital subtraction angiography.

    PubMed

    Shaw, C G; Plewes, D B

    1986-08-01

    The pulsed-injection method for measuring the velocity of blood flow in intraarterial digital subtraction angiography is described. With this technique, contrast material is injected at a pulsing frequency as high as 15 Hz, so that two or more boluses can be imaged simultaneously. The velocity of flow is determined by measuring the spacing between the boluses and multiplying it by the pulsing frequency. Results of tests with phantoms correlate well with flow measurements obtained with a graduated cylinder for velocities ranging from 8 to 60 cm/sec. The potential of the method for time-dependent velocity measurement has been demonstrated with simulated pulsatile flows. PMID:3523598

  9. Quantification of choroidal neovascularization vessel length using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Gao, Simon S.; Liu, Li; Bailey, Steven T.; Flaxel, Christina J.; Huang, David; Li, Dengwang; Jia, Yali

    2016-07-01

    Quantification of choroidal neovascularization (CNV) as visualized by optical coherence tomography angiography (OCTA) may have importance clinically when diagnosing or tracking disease. Here, we present an automated algorithm to quantify the vessel skeleton of CNV as vessel length. Initial segmentation of the CNV on en face angiograms was achieved using saliency-based detection and thresholding. A level set method was then used to refine vessel edges. Finally, a skeleton algorithm was applied to identify vessel centerlines. The algorithm was tested on nine OCTA scans from participants with CNV and comparisons of the algorithm's output to manual delineation showed good agreement.

  10. Angiography in the diagnosis and management of extracranial vascular lesions of the head and neck.

    PubMed

    Overholt, S L; Gado, M; Sessions, D G; Ogura, J H

    1978-11-01

    The angiographic features of various lesions of the head and neck are presented. Angiographically, cavernous hemangiomas display large venous lakes with calcified phleboliths. Arteriovenous malformations reveal massive tumor stain with well delineated feeding vessels from multiple systems. Chemodectomas and juvenile nasopharyngeal angiofibromas are clearly vascular with homogenous tumor staining in the capillary phase. Angiography of cavernous hemangioma, AVM, chemodectoma, and angiofibroma is diagnostic and may preclude the need for tissue biopsy. Angiographically neurilemmomas are less vascular with non-homogenous tumor stain. Carcinomas are typically avascular. The use and benefits of arterial embolization in the management of these lesions is presented.

  11. Realism, criterion validity, and training capability of simulated diagnostic cerebral angiography.

    PubMed

    Nguyen, Ngan; Eagleson, Roy; Boulton, Mel; de Ribaupierre, Sandrine

    2014-01-01

    Computer-based simulation is increasingly used in medical education for training, assessment, credentialing, and practice. Compared to medical specialties such as anesthesiology and general surgery, the adoption of simulation for neurointerventional training has been slow. This may be due to the limited number of neurointerventional simulators available and the lack of research assessing their validity and training capability. The objective of this study was to assess the realism, validity, and training capability of computer-based simulation for diagnostic cerebral angiography using a commercially available simulator called the ANGIO Mentor Express.

  12. [A case of pituitary adenoma progressing to pituitary apoplexy on the occasion of cerebral angiography].

    PubMed

    Suga, T; Kagawa, S; Goto, H; Yoshioka, K; Hosoya, T

    1996-05-01

    A case of pituitary adenoma which had progressed from subclinical pituitary apoplexy to subacute pituitary apoplexy on the occasion of cerebral angiography is reported. A 29-year-old man, complaining of bitemporal hemianopsia, was admitted to our department. Plain skull X-p revealed enlargement and double floor of the sella turcica. No abnormal calcification was revealed. CT demonstrated an isodensity mass with a diameter of 4 x 4 cm, and with ring enhancement in the suprasellar region. The mass extended from the intrasellar region to the suprasellar region and had a signal of high intensity on T1-weighted images. Endocrinological examination revealed hyperprolactinemia with a serum level of 422 ng/ml and normal reaction of anterior pituitary hormones. On 3rd March, digital subtraction angiography with 5F catheter was performed with the patient under sedation. The contrast medium was ioxaglic acid (Hexabrix 320). A volume of 6 ml with a speed of 4 ml per second was injected for the internal carotid angiogram. A total volume of 60 ml was used. Serum saline with 10 unit per ml of heparin sodium was also used for flushing. During angiography, the patient's blood pressure was 125/60-115/60mm Hg. DSA revealed upward displacement of the proximal portion of the anterior cerebral artery, pocket formation, and staining of the tumor capsule. Six hours later, he complained of retroorbital headache. Next morning, he noticed complete lack of left visual acuity. On 7th March, right visual acuity degenerated to blindness. CT revealed that the mass had increased its density. With bifrontal osteoplastic craniotomy, the tumor with marked intratumoral hemorrhage was resected. Its histology was chromophobe adenoma. The patient's right visual acuity improved rapidly. On the occasion of cerebral angiography, we could observe that subclinical pituitary apoplexy deteriorated to subacute pituitary apoplexy. Rosenbaum postulated that injection of contrast media increased intravascular

  13. Equitable random graphs

    NASA Astrophysics Data System (ADS)

    Newman, M. E. J.; Martin, Travis

    2014-11-01

    Random graph models have played a dominant role in the theoretical study of networked systems. The Poisson random graph of Erdős and Rényi, in particular, as well as the so-called configuration model, have served as the starting point for numerous calculations. In this paper we describe another large class of random graph models, which we call equitable random graphs and which are flexible enough to represent networks with diverse degree distributions and many nontrivial types of structure, including community structure, bipartite structure, degree correlations, stratification, and others, yet are exactly solvable for a wide range of properties in the limit of large graph size, including percolation properties, complete spectral density, and the behavior of homogeneous dynamical systems, such as coupled oscillators or epidemic models.

  14. Hypothetical ratings of coronary angiography appropriateness: are they associated with actual angiographic findings, mortality, and revascularisation rate? The ACRE study

    PubMed Central

    Hemingway, H; Crook, A; Banerjee, S; Dawson, J; Feder, G; Magee, P; Wood, A; Philpott, S; Timmis, A

    2001-01-01

    OBJECTIVE—To determine whether ratings of coronary angiography appropriateness derived by an expert panel on hypothetical patients are associated with actual angiographic findings, mortality, and subsequent revascularisation in the ACRE (appropriateness of coronary revascularisation) study.
DESIGN—Population based, prospective study. The ACRE expert panel rated hypothetical clinical indications as inappropriate, uncertain, or appropriate before recruitment of a cohort of real patients.
SETTING—Royal Hospitals Trust, London, UK.
PARTICIPANTS—3631 consecutive patients undergoing coronary angiography (no exclusion criteria).
MAIN OUTCOME MEASURES—Angiographic findings, mortality (n = 226 deaths), and revascularisation (n = 1556 procedures) over 2.5 years of follow up.
RESULTS—The indications for coronary angiography were rated appropriate in 2253 (62%) patients. 166 (5%) coronary angiograms were performed for indications rated inappropriate, largely for asymptomatic or atypical chest pain presentations. The remaining 1212 (33%) angiograms were rated uncertain, of which 47% were in patients with mild angina and no exercise ECG or in patients with unstable angina controlled by inpatient management. Three vessel disease was more likely among appropriate cases and normal coronaries were more likely among inappropriate cases (p < 0.001). Mortality and revascularisation rates were highest among patients with an appropriate indication, intermediate in those with an uncertain indication, and lowest in the inappropriate group (log rank p = 0.018 and p < 0.0001, respectively).
CONCLUSION—The ACRE ratings of appropriateness for angiography predicted angiographic findings, mortality, and revascularisation rates. These findings support the clinical usefulness of expert panel methods in defining criteria for performing coronary angiography.


Keywords: coronary artery disease; coronary angiography; coronary artery bypass graft

  15. Cortical Blindness and Retrograde Amnesia Following Cerebral Angiography Studied by Early Diffusion Weighted MR imaging. A Case Report.

    PubMed

    Roccatagliata, L; Taveira-Lopes, L; Rossignol, M-D; Biondi, A

    2009-12-14

    Cortical blindness is a well described neuro-ophthalmologic complication of angiography due to neurotoxicity following contrast media exposure. A rarer association with retrograde amnesia has also been reported. Since ischemic stroke due to embolism remains the most common aetiology of neurological complications of diagnostic and therapeutic arterial catheterisation, prompt identification of the mechanism responsible for the clinical symptoms is essential for patient management. Although CT and conventional MRI findings have been reported in this condition, experience with diffusion weighted (DW) sequences is lacking especially in cases associated with memory impairment. A 65-year-old man with tinnitus underwent cerebral angiography for suspicion of a dural arteriovenous fistula. During the procedure the patient developed complete loss of vision and rapidly became confused. Brain CT showed bilateral cortical enhancement in the occipital lobes. MR with DWI was performed 3.5 hours after angiography. Early DWI showed no signal abnormalities thereby excluding an ischaemic complication. Gradual improvement of visual function occurred over the next 24 hours. After 48 hours the patient was alert and orientated but profound retrograde amnesia persisted with no memory for the events of the day of angiography. CT follow-up at one year was normal. DWI is invaluable in the evaluation of patients with cortical blindness with or without memory deficits precipitated by angiography and may advance understanding of the pathophysiology. Diffusion-weighted MRI is crucial in differentiating neuro-ophthalmologic complications precipitated by intracortical contrast leakage after angiography from an ischaemic stroke needing a prompt and often invasive treatment. PMID:24209406

  16. 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

  17. Complications following transfemoral cerebral angiography for cerebral ischemia. Report of 159 angiograms and correlation with surgical risk.

    PubMed

    Theodotou, B C; Whaley, R; Mahaley, M S

    1987-08-01

    One hundred fifty-nine transfemoral cerebral angiograms for patients with carotid stenosis who subsequently underwent carotid endarterectomy were reviewed. No patient with an asymptomatic carotid bruit developed cerebrovascular complications during angiography. Patients with transient ischemic attacks (TIAs) had a 4.5% incidence of complications. Patients with stroke in evolution had a complication rate of 7.7%. Patients with completed strokes had no angiographic complications. No complication lasted more than 1 hour; all occurred during angiography or immediately afterwards. Stroke in progress has too high a surgical and angiographic risk to warrant study. Transient ischemic attacks have an acceptable morbidity both surgically and angiographically. PMID:3603359

  18. Preventing radiocontrast-induced nephropathy in chronic kidney disease patients undergoing coronary angiography

    PubMed Central

    Hung, Yao-Min; Lin, Shoa-Lin; Hung, Shih-Yuan; Huang, Wei-Chun; Wang, Paul Yung-Pou

    2012-01-01

    Radiocontrast-induced nephropathy (RCIN) is an acute and severe complication after coronary angiography, particularly for patients with pre-existing chronic kidney disease (CKD). It has been associated with both short- and long-term adverse outcomes, including the need for renal replacement therapy, increased length of hospital stay, major cardiac adverse events, and mortality. RCIN is generally defined as an increase in serum creatinine concentration of 0.5 mg/dL or 25% above baseline within 48 h after contrast administration. There is no effective therapy once injury has occurred, therefore, prevention is the cornerstone for all patients at risk for acute kidney injury (AKI). There is a small but growing body of evidence that prevention of AKI is associated with a reduction in later adverse outcomes. The optimal strategy for preventing RCIN has not yet been established. This review discusses the principal risk factors for RCIN, evaluates and summarizes the evidence for RCIN prophylaxis, and proposes recommendations for preventing RCIN in CKD patients undergoing coronary angiography. PMID:22655164

  19. Relationship between Functional and Structural Changes in Diabetic Vessels in Optical Coherence Tomography Angiography

    PubMed Central

    Miwa, Yuko; Murakami, Tomoaki; Suzuma, Kiyoshi; Uji, Akihito; Yoshitake, Shin; Fujimoto, Masahiro; Yoshitake, Tatsuya; Tamura, Yukino; Yoshimura, Nagahisa

    2016-01-01

    The decorrelation signals in optical coherence tomography angiography (OCTA) are derived from the flow of erythrocytes and concomitantly delineate the retinal vasculature. We compared the structural and functional characteristics of vascular lesions visualized in fluorescein angiography (FA), OCTA, and en-face OCT images in 53 eyes (28 patients) with diabetic retinopathy (DR). The foveal avascular zone (FAZ) areas in OCTA images in the superficial layer almost corresponded to those in FA images. The FAZ areas in the en-face OCT images in the superficial layer were smaller than those in the FA images and correlated with each other, which agreed with the finding that en-face OCT images often delineated the vascular structure in the nonperfused areas in FA images. Microaneurysms appeared as fusiform, saccular, or coiled capillaries in OCTA images and ringed, round, or oval hyperreflective lesions in en-face OCT images. OCTA and en-face OCT images detected 41.0 ± 16.1% and 40.1 ± 18.6%, respectively, of microaneurysms in FA images, although both depicted only 13.9 ± 16.4%. The number of microaneurysms in FA images was correlated with that in OCTA and en-face OCT images. Comparisons of these modalities showed the associations and dissociations between blood flow and vascular structures, which improves the understanding of the pathogenesis of DR. PMID:27350562

  20. Optical coherence tomography angiography of stimulus evoked hemodynamic responses in individual retinal layers.

    PubMed

    Son, Taeyoon; Wang, Benquan; Thapa, Damber; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2016-08-01

    Blood flow changes are highly related to neural activities in the retina. It has been reported that neural activity increases when flickering light stimulation of the retina is used. It is known that blood flow changes with flickering light stimulation can be altered in patients with vascular disease and that measurement of flicker-induced vasodilatation is an easily applied tool for monitoring functional microvascular alterations. However, details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood due to the limitation of existing techniques. In this study, flickering light stimulation was applied to mouse retinas to investigate stimulus evoked hemodynamic responses in individual retinal layers. A spectral domain optical coherence tomography (OCT) angiography imaging system was developed to provide dynamic mapping of hemodynamic responses in the ganglion cell layer, inner plexiform layer, outer plexiform layer and choroid layer before, during and after flickering light stimulation. Experimental results showed hemodynamic responses with different magnitudes and time courses in individual retinal layers. We anticipate that the dynamic OCT angiography of stimulus evoked hemodynamic responses can greatly foster the study of neurovascular coupling mechanisms in the retina, promising new biomarkers for retinal disease detection and diagnosis. PMID:27570706

  1. 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.

  2. 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.

  3. Evaluation of iterative sparse object reconstruction from few projections for 3-D rotational coronary angiography.

    PubMed

    Hansis, Eberhard; Schäfer, Dirk; Dössel, Olaf; Grass, Michael

    2008-11-01

    A 3-D reconstruction of the coronary arteries offers great advantages in the diagnosis and treatment of cardiovascular disease, compared to 2-D X-ray angiograms. Besides improved roadmapping, quantitative vessel analysis is possible. Due to the heart's motion, rotational coronary angiography typically provides only 5-10 projections for the reconstruction of each cardiac phase, which leads to a strongly undersampled reconstruction problem. Such an ill-posed problem can be approached with regularized iterative methods. The coronary arteries cover only a small fraction of the reconstruction volume. Therefore, the minimization of the mbiL(1) norm of the reconstructed image, favoring spatially sparse images, is a suitable regularization. Additional problems are overlaid background structures and projection truncation, which can be alleviated by background reduction using a morphological top-hat filter. This paper quantitatively evaluates image reconstruction based on these ideas on software phantom data, in terms of reconstructed absorption coefficients and vessel radii. Results for different algorithms and different input data sets are compared. First results for electrocardiogram-gated reconstruction from clinical catheter-based rotational X-ray coronary angiography are presented. Excellent 3-D image quality can be achieved. PMID:18955171

  4. 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.

  5. [ECG-gated bypass CT angiography--application in imaging arterial bypasses].

    PubMed

    Wintersperger, B J; Bastarrika, G; Nikolaou, K; Rist, C; Huber, A; Knez, A; Reiser, M F; Becker, C R; Vicol, C

    2004-02-01

    Nowadays coronary artery bypass grafting is increasingly performed using arterial grafts. Purpose of the study was the evaluation of a appropriate 16 detector-row CT angiography protocol in patients after predominantly arterial bypass grafting. Fourteen patients after bypass grafting were including into the study and CT angiography carried out in the early postoperative period using a 16 detector-row CT system. To reduce cardiac pulsation artifacts data acquisition was implemented using ECG-gating algorithms. Overall 43 grafts (37 arterial, 6 venous) were examined. In 13 patients surgery had been performed using composite grafts with T or TY configuration. The mean heart rate was 74.1 bpm and showed a negative correlation to the image quality (r=-0.65; p=0.01). However, all data sets were diagnostic. Contrast injection protocol allowed for a homogeneous opacification throughout the vessels of interest. All non-delineationable grafts (5) showed a close proximity to the heart (T or Y grafts). Cardiac surgery is increasingly focusing on arterial revascularisation in bypass grafting and therefore leading to new demands for non-invasive bypass graft imaging. 16 detector-row CT allows a reliable visualization of even composite arterial grafts. However, for detection of grafts in the proximity of the heart a reduction of the heart rate (<65-70) still seems to be necessary. PMID:14991132

  6. Helical CT Angiography of Abdominal Aortic Aneurysms Treated with Suprarenal Stent Grafting: A Pictorial Essay

    SciTech Connect

    Sun Zhonghua

    2003-06-15

    The endovascular repair of abdominal aorticaneurysm (AAA) with stent grafts is rapidly becoming an important alternative to open repair. Suprarenal stent grafting, recently modified from conventional infrarenal stent grafting, is a technique for the purpose of treating patients with inappropriate aneurysm necks.Unlike open repair, the success of endoluminal repair cannot be ascertained by means of direct examination and thus relies on imaging results. The use of conventional angiography for arterial imaging has become less dominant, while helical computed tomography angiography(CTA) has become the imaging modality of choice for both preoperative assessment and postoperative followup after treatment with stent graft implants. There is an increasing likelihood that radiologists will become more and more involved in the procedure of aortic stent grafting and in giving the radiological report on these patients treated with stent grafts. It is necessary for radiologists to be familiar with the imaging findings, including common and uncommon appearances following aortic stent grafting. The purpose of this pictorial essay is to describe and present normal and abnormal imaging appearances following aortic stent grafting based on helical CTA.

  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. [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. PMID:8393309

  10. Direct-conversion flat-panel detector for region-of-interest angiography

    NASA Astrophysics Data System (ADS)

    Ganguly, Arundhuti; Rudin, Stephen; Bednarek, Daniel R.; Hoffmann, Kenneth R.; Yang, Chang-Ying J.; Wang, Zhou

    2001-06-01

    Minimally invasive image-guided interventions require very high image resolution and quality, specifically over regions-of-interest (ROI) crucial to the procedure. An ROI high quality image allows limited patient radiation deposition while permitting rapid frame transfer rates. Considering current developments in direct conversion Flat Panel Detectors (FPD), advantages of such an imager for ROI angiography were investigated. The performance of an amorphous-selenium based FPD was simulated to evaluate improvements in MTF and DQE under various angiographic imaging conditions. The detector envisioned incorporates the smallest pixel size of 70 mm, reported to date, and a photoconductor thickness of 1000 mm to permit angiography. The MTF of the FPD is calculated to be 60% at the Nyquist frequency of 7.1 lp/mm compared to 6% for a previously reported CsI(Tl)-based ROI CCD camera. The DQE(0) of the FPD at 0.7 mR and 70 kVp is 74% while for the CCD camera is 70%. At 7.1 lp/mm, the FPD's DQE is 26% while for the CCD camera it is 12%. Images of an undeployed stent with 70 mm pixel mammography FPD prototype, compare favorably with images acquired with the CCD camera. Thus a practical direct flat-panel ROI detector with both improved performance and physical size is proposed.

  11. SLO angiography: arterio-venous filling times in monkey and minipig.

    PubMed

    Rosolen, Serge G; Saint-Macary, Gérard; Gautier, Vincent; Le Gargasson, Jean-François

    2002-03-01

    Confocal scanning laser ophthalmoscope (cSLO) is a new technique which enables ocular fundus image recording and dynamic retinal angiography to be performed. The ocular fundus image is acquired sequentially, point by point, and is reconstructed on a video monitor at the rate of 25 images per second. The aim of this paper is to evaluate the feasibility of measuring retinal arterio-venous filling times (AVFT) with a I + Tech cSLO. Three young adult cynomolgus monkeys and three young adult Göttingen minipigs were used as experimental models. All animals were anesthetized using a zolazepam + tiletamine mixture injected intramuscularly; heart rate and rectal temperature were monitored and corneal irrigation was regularly performed. For all subjects, prior to examination, hematocrit and globe axial length were measured. The images were recorded, stabilized and analyzed. The retinal examination consisted of retinal images with 40 degrees field cSLO, retinal fluorescein angiography and arterio-venous 50% filling time measurements. For each subject all images were easily recorded while keeping the animals in a normally lighted room without having to use any additional optical device. AVFT using an I + Tech cSLO is easily performed in monkeys and minipigs. AVFT measurements in minipigs and monkeys are similar. These results suggest that minipigs can replace monkeys as an experimental species for AVFT investigations. PMID:11940243

  12. 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.

  13. A feasibility study for compressed sensing combined phase contrast MR angiography reconstruction

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Hoon; Hong, Cheol-Pyo; Lee, Man-Woo; Han, Bong-Soo

    2012-02-01

    Phase contrast magnetic resonance angiography (PC MRA) is a technique for flow velocity measurement and vessels visualization, simultaneously. The PC MRA takes long scan time because each flow encoding gradients which are composed bipolar gradient type need to reconstruct the angiography image. Moreover, it takes more image acquisition time when we use the PC MRA at the low-tesla MRI system. In this study, we studied and evaluation of feasibility for CS MRI reconstruction combined PC MRA which data acquired by low-tesla MRI system. We used non-linear reconstruction algorithm which named Bregman iteration for CS image reconstruction and validate the usefulness of CS combined PC MRA reconstruction technique. The results of CS reconstructed PC MRA images provide similar level of image quality between fully sampled reconstruction data and sparse sampled reconstruction using CS technique. Although our results used half of sampling ratio and do not used specification hardware device or performance which are improving the temporal resolution of MR image acquisition such as parallel imaging reconstruction using phased array coil or non-cartesian trajectory, we think that CS combined PC MRA technique will be helpful to increase the temporal resolution and at low-tesla MRI system.

  14. Sparsity-constrained three-dimensional image reconstruction for C-arm angiography.

    PubMed

    Rashed, Essam A; al-Shatouri, Mohammad; Kudo, Hiroyuki

    2015-07-01

    X-ray C-arm is an important imaging tool in interventional radiology, road-mapping and radiation therapy because it provides accurate descriptions of vascular anatomy and therapeutic end point. In common interventional radiology, the C-arm scanner produces a set of two-dimensional (2D) X-ray projection data obtained with a detector by rotating the scanner gantry around the patient. Unlike conventional fluoroscopic imaging, three-dimensional (3D) C-arm computed tomography (CT) provides more accurate cross-sectional images, which are helpful for therapy planning, guidance and evaluation in interventional radiology. However, 3D vascular imaging using the conventional C-arm fluoroscopy encounters some geometry challenges. Inspired by the theory of compressed sensing, we developed an image reconstruction algorithm for conventional angiography C-arm scanners. The main challenge in this image reconstruction problem is the projection data limitations. We consider a small number of views acquired from a short rotation orbit with offset scan geometry. The proposed method, called sparsity-constrained angiography (SCAN), is developed using the alternating direction method of multipliers, and the results obtained from simulated and real data are encouraging. SCAN algorithm provides a framework to generate 3D vascular images using the conventional C-arm scanners in lower cost than conventional 3D imaging scanners.

  15. Remapping of digital subtraction angiography on a standard fluoroscopy system using 2D-3D registration

    NASA Astrophysics Data System (ADS)

    Alhrishy, Mazen G.; Varnavas, Andreas; Guyot, Alexis; Carrell, Tom; King, Andrew; Penney, Graeme

    2015-03-01

    Fluoroscopy-guided endovascular interventions are being performing for more and more complex cases with longer screening times. However, X-ray is much better at visualizing interventional devices and dense structures compared to vasculature. To visualise vasculature, angiography screening is essential but requires the use of iodinated contrast medium (ICM) which is nephrotoxic. Acute kidney injury is the main life-threatening complication of ICM. Digital subtraction angiography (DSA) is also often a major contributor to overall patient radiation dose (81% reported). Furthermore, a DSA image is only valid for the current interventional view and not the new view once the C-arm is moved. In this paper, we propose the use of 2D-3D image registration between intraoperative images and the preoperative CT volume to facilitate DSA remapping using a standard fluoroscopy system. This allows repeated ICM-free DSA and has the potential to enable a reduction in ICM usage and radiation dose. Experiments were carried out using 9 clinical datasets. In total, 41 DSA images were remapped. For each dataset, the maximum and averaged remapping accuracy error were calculated and presented. Numerical results showed an overall averaged error of 2.50 mm, with 7 patients scoring averaged errors < 3 mm and 2 patients < 6 mm.

  16. 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.

  17. 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.

  18. Contrast enhanced pulmonary magnetic resonance angiography for pulmonary embolism: Building a successful program.

    PubMed

    Nagle, Scott K; Schiebler, Mark L; Repplinger, Michael D; François, Christopher J; Vigen, Karl K; Yarlagadda, Rajkumar; Grist, Thomas M; Reeder, Scott B

    2016-03-01

    The performance of contrast enhanced pulmonary magnetic resonance angiography (MRA) for the diagnosis of pulmonary embolism (PE) is an effective non-ionizing alternative to contrast enhanced computed tomography and nuclear medicine ventilation/perfusion scanning. However, the technical success of these exams is very dependent on careful attention to the details of the MRA acquisition protocol and requires reader familiarity with MRI and its artifacts. Most practicing radiologists are very comfortable with the performance and interpretation of computed tomographic angiography (CTA) performed to detect pulmonary embolism but not all are as comfortable with the use of MRA in this setting. The purpose of this review is to provide the general radiologist with the tools necessary to build a successful pulmonary embolism MRA program. This review will cover in detail image acquisition, image interpretation, and some key elements of outreach that help to frame the role of MRA to consulting clinicians and hospital administrators. It is our aim that this resource will help build successful clinical pulmonary embolism MRA programs that are well received by patients and physicians, reduce the burden of medical imaging radiation, and maintain good patient outcomes. PMID:26860667

  19. 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.

  20. Optical coherence tomography angiography of stimulus evoked hemodynamic responses in individual retinal layers

    PubMed Central

    Son, Taeyoon; Wang, Benquan; Thapa, Damber; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng

    2016-01-01

    Blood flow changes are highly related to neural activities in the retina. It has been reported that neural activity increases when flickering light stimulation of the retina is used. It is known that blood flow changes with flickering light stimulation can be altered in patients with vascular disease and that measurement of flicker-induced vasodilatation is an easily applied tool for monitoring functional microvascular alterations. However, details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood due to the limitation of existing techniques. In this study, flickering light stimulation was applied to mouse retinas to investigate stimulus evoked hemodynamic responses in individual retinal layers. A spectral domain optical coherence tomography (OCT) angiography imaging system was developed to provide dynamic mapping of hemodynamic responses in the ganglion cell layer, inner plexiform layer, outer plexiform layer and choroid layer before, during and after flickering light stimulation. Experimental results showed hemodynamic responses with different magnitudes and time courses in individual retinal layers. We anticipate that the dynamic OCT angiography of stimulus evoked hemodynamic responses can greatly foster the study of neurovascular coupling mechanisms in the retina, promising new biomarkers for retinal disease detection and diagnosis. PMID:27570706

  1. Intracranial MR angiography: Its role in the integrated approach to brain infarction

    SciTech Connect

    Johnson, B.A.; Heiserman, J.E.; Drayer, B.P.; Keller, P.J.

    1994-05-01

    To determine the contribution of cranial MR angiography (MRA) for the evaluation of patients with acute and subacute brain infarction. MR and MRA studies performed on 78 adult patients with acute and subacute stroke were retrospectively reviewed and correlated with the clinical records. There were 50 acute and 28 subacute infarctions in our series. Five of 78 MRA exams (6%) were nondiagnostic. Sixty examinations (80%) were positive for stenosis or occlusion. The distribution of stenotic or occlusive vascular lesions correlated with the location of infarction in 56 of the 60 positive cases (93%). MRA provided information not obtained from the MR images in 40 cases (55%). One hundred four individual vessels in 8 patients who underwent conventional cerebral angiography were compared with the MRA appearance. The MRA interpretations correlated with the conventional angiographic evaluations for 90 vessels (87%). Vascular lesions demonstrated on intracranial MRA show a high correlation with infarct distribution. MRA provides information adjunctive to conventional MR in a majority of cases. We conclude that MRA is an important component of the complete evaluation of brain infarction. 39 refs., 3 figs., 2 tabs.

  2. Characterization of rat model of acute anterior uveitis using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-03-01

    Uveitis, or ocular inflammation, is a cause of severe visual impairment. Rodent models of uveitis are powerful tools used to investigate the pathological mechanisms of ocular inflammation and to study the efficacy of new therapies prior to human testing. In this paper, we report the utility of spectral-domain optical coherence tomography (SD-OCT) angiography in characterizing the inflammatory changes induced in the anterior segment of a rat model of uveitis. Acute anterior uveitis (AAU) was induced in two rats by intravitreal injection of a killed mycobacterial extract. One of them received a concurrent periocular injection of steroids to model a treatment effect. OCT imaging was performed prior to inflammation induction on day 0 (baseline), and 2 days post-injection (peak inflammation). Baseline and inflamed images were compared. OCT angiography identified swelling of the cornea, inflammatory cells in the anterior and posterior chambers, a fibrinous papillary membrane, and dilation of iris vessels in the inflamed eyes when compared to baseline images. Steroid treatment was shown to prevent the changes associated with inflammation. This is a novel application of anterior OCT imaging in animal models of uveitis, and provides a high resolution, in vivo assay for detecting and quantifying ocular inflammation and the response to new therapies.

  3. Hematological Parameters Improve Prediction of Mortality and Secondary Adverse Events in Coronary Angiography Patients

    PubMed Central

    Gijsberts, Crystel M.; den Ruijter, Hester M.; de Kleijn, Dominique P.V.; Huisman, Albert; ten Berg, Maarten J.; van Wijk, Richard H.A.; Asselbergs, Folkert W.; Voskuil, Michiel; Pasterkamp, Gerard; van Solinge, Wouter W.; Hoefer, Imo E.

    2015-01-01

    Abstract Prediction of primary cardiovascular events has been thoroughly investigated since the landmark Framingham risk score was introduced. However, prediction of secondary events after initial events of coronary artery disease (CAD) poses a new challenge. In a cohort of coronary angiography patients (n = 1760), we examined readily available hematological parameters from the UPOD (Utrecht Patient Oriented Database) and their addition to prediction of secondary cardiovascular events. Backward stepwise multivariable Cox regression analysis was used to test their ability to predict death and major adverse cardiovascular events (MACE). Continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) measures were calculated for the hematological parameters on top of traditional risk factors to assess prediction improvement. Panels of 3 to 8 hematological parameters significantly improved prediction of death and adverse events. The IDIs ranged from 0.02 to 0.07 (all P < 0.001) among outcome measures and the cNRIs from 0.11 to 0.40 (P < 0.001 in 5 of 6 outcome measures). In the hematological panels red cell distribution width (RDW) appeared most often. The multivariable adjusted hazard ratio of RDW per 1 standard deviation (SD) increase for MACE was 1.19 [1.08–1.32], P < 0.001. Routinely measured hematological parameters significantly improved prediction of mortality and adverse events in coronary angiography patients. Accurately indicating high-risk patients is of paramount importance in clinical decision-making. PMID:26559287

  4. PULMONARY ANGIOGRAPHY WITH 64-MULTIDETECTOR-ROW COMPUTED TOMOGRAPHY IN NORMAL DOGS

    PubMed Central

    Drees, Randi; Frydrychowicz, Alex; Keuler, Nicholas S.; Reeder, Scott B.; Johnson, Rebecca

    2012-01-01

    Pulmonary angiography using 64-multidetector-row computed tomography (MDCT) was used to evaluate pulmonary artery anatomy, and determine the sensitivity of pulmonary artery segment visualization in four Beagle dogs using images reconstructed to 0.625 mm and retro-reconstructed to 1.25 and 2.5 mm slice thickness. Morphologically, characteristic features included a focal narrowing in the right cranial pulmonary artery in all dogs, which should not be mistaken as stenosis. While the right cranial pulmonary artery divided into two equally sized branches that were tracked into the periphery of the lung lobe in all dogs, only a single left cranial (cranial portion) lobar artery was present. Compared with 1.25 and 2.5 mm retro-reconstructions, 0.625 mm reconstructions allowed for detection of significantly (P ≤ 0.05) more pulmonary artery segments and sharper depiction of vessel margins. Clinical applications such as prevalence and significance of diameter changes, and detection of pulmonary arterial thrombembolism on lobar and sublobar level, using pulmonary angiography with 64-MDCT applying 0.625 mm reconstruction slice thickness remain to be established. PMID:21545367

  5. The Role of Catheter Angiography in the Diagnosis of Central Nervous System Vasculitis

    PubMed Central

    Edgell, Randall C.; Sarhan, Ahmed E.; Soomro, Jazba; Einertson, Collin; Kemp, Joanna; Shirani, Peyman; Malmstrom, Theodore K.; Coppens, Jeroen

    2016-01-01

    Background Central nervous system vasculitis (CNSV) is a rare disorder, the pathophysiology of which is not fully understood. It involves a combination of inflammation and thrombosis. CNSV is most commonly associated with headache, gradual changes in mental status, and focal neurological symptoms. Diagnosis requires the effective use of history, laboratory testing, imaging, and biopsy. Catheter angiography can be a powerful tool in the diagnosis when common and low-frequency angiographic manifestations of CNSV are considered. We review these manifestations and their place in the diagnostic algorithm of CNSV. Summary We reviewed the PubMed database for case series of CNSV that included 5 or more patients. Demographic and angiographic findings were collected. Angiographic findings were dichotomized between common and low-frequency findings. A system for incorporating these findings into clinical decision-making is proposed. Key Message CNSV is a diagnostic challenge due to the absence of a true gold standard test. In the absence of such a test, catheter angiography remains a central piece of the diagnostic puzzle when appropriately employed and interpreted. PMID:27781050

  6. 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.

  7. 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.

  8. Prognostic Value of Coronary Computed Tomography (CT) Angiography and Coronary Artery Calcium Score Performed Before Revascularization

    PubMed Central

    Fujimoto, Shinichiro; Kondo, Takeshi; Kumamaru, Kanako K; Shinozaki, Tomohiro; Takamura, Kazuhisa; Kawaguchi, Yuko; Matsumori, Rie; Hiki, Makoto; Miyauchi, Katsumi; Daida, Hiroyuki; Rybicki, Frank J

    2015-01-01

    Background Cardiac events after revascularization are equally attributable to recurrence at site of culprit lesions and development of nonculprit lesions. We evaluated the hypothesis that coronary computed tomography (CT) angiography and coronary artery calcium score (CACS) performed before revascularization predicts cardiac events after treatment. Methods and Results Among 2238 consecutive patients without known coronary artery disease who underwent coronary CT angiography and CACS, 359 patients underwent revascularization within 30 days after CT; in 337 of 359 (93.9%) follow-up clinical information was available. In addition to known cardiac risk factors, CT findings were evaluated as predictors of cardiac events after revascularization: CACS and the presence of CT-verified high-risk plaque (CT-HRP). Improvement of predictive accuracy by including CT findings was evaluated from a discrimination (Harrell’s C-statistics) standpoint. During the follow-up period (median: 673, interquartile range: 47 to 1529 days), a total of 98 cardiac events occurred. Cox proportional hazard model revealed that age, diabetes, triglyceride, CACS, and nonculprit CT-HRP were significant predictors of overall cardiac events. Although not statistically significant, discriminatory power was greater for the model with CACS (C-stat: 63.2%) and the model with both CACS and CT-HRP (65.8%) compared to the model including neither CACS nor CT-HRP (60.7%). Conclusions High CACS and the presence of nonculprit CT-HRP performed before revascularization are significant predictors of cardiac events after revascularization. PMID:26296858

  9. 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

  10. Optical Coherence Tomography Angiography of Type 2 Neovascularization in Age-Related Macular Degeneration.

    PubMed

    Souied, Eric H; El Ameen, Ala; Semoun, Oudy; Miere, Alexandra; Querques, Giuseppe; Cohen, Salomon Yves

    2016-01-01

    Well-defined choroidal neovascularization, known as type 2 neovascularization (NV) or classic NV, is the least representative phenotype of exudative age-related macular degeneration. Clinical aspects of type 2 NV have been widely described in the literature, and to date fluorescein angiography remains the gold standard for imaging age-related macular degeneration at initial presentation. Optical coherence tomography angiography (OCT-A) can be used to image vessels based on flow characteristics without any dye injection. Type 2 NV can be visualized using OCT-A with very typical patterns. A neovascular membrane appears as either a medusa-shaped complex or a glomerulus-shaped lesion in the outer retina and the choriocapillaris layer. Furthermore, in the choriocapillaris layer, the external borders of the lesion appear as a dark ring in most cases, and one or more central feeder vessels that extend deeply into the more profound choroidal layers are visible. Identification of type 2 NV is easily feasible for any clinician using OCT-A, especially in areas where there are normally no vessels, like in subretinal space, if the interpretation rules are respected. PMID:27023798

  11. In vivo monitoring of external pressure induced hemodynamics in skin tissue using optical coherence tomography angiography

    NASA Astrophysics Data System (ADS)

    Choi, Woo June; Wang, Hequn; Wang, Ruikang K.

    2015-03-01

    Characterization of the relationship between external pressure and blood flow is important in the examination of pressure-induced disturbance in tissue microcirculation. Optical coherence tomography (OCT) angiography is a promising imaging technique, capable of providing the noninvasive extraction of functional vessels within the skin tissue with capillary-scale resolution. Here, we present a feasibility study of OCT angiography to monitor effect of external pressures on blood perfusion in human skin tissue in vivo. Graded external pressure is loaded normal to the surface of the nailfold tissue of a healthy human. The incremental loading is applied step by step and then followed by an immediate release. Concurrent OCT imaging of the nailfold is performed during the pre/post loading. Blood perfusion images including baseline (at pre-loading) and corresponding tissue strain maps are calculated from 3D OCT dataset obtained at the different applied pressures, allowing visualization of capillary perfusion events at stressed nailfold tissue. The results indicate that the perfusion progressively decreases with the constant increase of tissue strain. Reactive hyperemia is occurred right after the removal of the pressure corresponding to quick drop of the increased strain. The perfusion is returned to the baseline level after a few minutes. These findings suggest that OCT microangiography may have great potential for quantitatively assessing tissue microcirculation in the locally pressed tissue in vivo.

  12. Subarachnoid hemorrhage and negative angiography: clinical course and long-term follow-up.

    PubMed

    Fontanella, Marco; Rainero, Innocenzo; Panciani, Pier Paolo; Schatlo, Bawarjan; Benevello, Chiara; Garbossa, Diego; Carlino, Christian; Valfrè, Walter; Griva, Federico; Bradac, Gianni Boris; Ducati, Alessandro

    2011-10-01

    The aim of this study was to investigate the long-term natural history of nontraumatic angiogram-negative subarachnoid hemorrhage with typical pretruncal (P-SAH) and diffuse (D-SAH) pattern of hemorrhage. A retrospective review of 102 patients who experienced angiographically negative SAH at our institution was undertaken (11.6% of 882 spontaneous SAH). Follow-ups were obtained at 7.9 to 16 years. In the D-SAH group, 11 patients (13.9%) out of 79 had an aneurysm, and four (5.1%) had rebleeding episodes. In the P-SAH group, the second angiography was negative in all of the 23 cases, and no rebleeding episodes were recorded. The long-term follow-up confirms that P-SAH is a benign disease. A second angiography could not be necessary. D-SAH is probably due to an aneurysm that thrombose early after the bleeding. At short-term follow-up, the sack could frequently recanalize and rebleed, whereas a late follow-up shows that rebleeding is very rare.

  13. 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. PMID:27403020

  14. A case of iatrogenic cerebral infarction demonstrated by postmortem cerebral angiography.

    PubMed

    Tajima, Yutaka; Takagi, Rie; Kominato, Yoshihiko; Kuwayama, Naoya

    2007-11-01

    A 37-year-old man with a meningioma compressing the right frontal lobe underwent preoperative embolization of the feeding vessels from the right meningeal artery. Although the first challenge was apparently successful, an excess amount of embolization agent was accidentally injected during the next procedure. X-ray monitoring demonstrated flow of contrast medium into the right internal carotid, anterior and middle cerebral arteries, and then the patient suddenly developed left hemiparesis, nausea, and deep coma. He died 48 days after the embolization treatment without improvement of the coma. A medicolegal autopsy was performed to determine whether malpractice had occurred during the embolization procedure. An internal examination demonstrated massive necrosis of the cerebral hemispheres and lobar pneumonia with abscess in the lungs. Due to the extensive brain necrosis, it was impossible to carry out ordinary macroscopic examination to identify the precise site of the craniocerebral vessel occlusion. Postmortem angiography was therefore performed, and this successfully revealed occlusion of the right internal carotid artery. In this case, postmortem angiography played a key role in identification of the intracranial vascular lesion that was responsible for the iatrogenic cerebral infarction.

  15. Effect of obesity on coronary artery plaque using 64 slice multidetector cardiac computed tomography angiography.

    PubMed

    Isma'eel, Hussain; Tellalian, David; Hamirani, Yasmin S; Kadakia, Jigar; Nasir, Khurram; Budoff, Matthew J

    2010-04-30

    Patients with a coronary artery calcification score (CACS) of zero and an intermediate risk of coronary artery disease have been shown to have a low prevalence of non-calcified coronary artery plaque (NCP). 181 consecutive patients with CAC 'zero', undergoing cardiac computed tomography angiography (CCTA) angiography at our center were evaluated. Presence of detectable NCP on CCTA in these patients was 13.8%. Mild non-obstructive disease (<30% and limited to one segment) was present in 76% of patients while only one patient (0.6%) had significant stenosis (>50%). Traditional risk factors were not found to be associated with the presence of NCP. However higher body mass index (BMI) was strongly found to be associated with NCP (31.6 in patients with NCP vs. 27.6 kg/m(2) in patients without NCP, p<.05). Obesity was 2.76 times more likely to be associated with NCP as compared to normal BMI (p<0.05).

  16. Response of left ventricular ejection fraction to recovery from general anesthesia: measurement by gated radionuclide angiography

    SciTech Connect

    Coriat, P.; Mundler, O.; Bousseau, D.; Fauchet, M.; Rous, A.C.; Echter, E.; Viars, P.

    1986-06-01

    To test the hypothesis that, after anesthesia for noncardiac surgical procedures, the increased cardiac work during recovery induces wall motion and ejection fraction (EF) abnormalities in patients with mild angina pectoris, gated radionuclide angiography was performed in patients undergoing simple cholecystectomy under narcotic-relaxant general anesthesia. The ejection fraction was determined during anesthesia at the end of surgery, and then determined 3 min and 3 hr after extubation. A new angiography was performed 24 hr later, and a myocardial scintigraphy (Thallium 201) was performed during infusion of the coronary vasodilator, dipyridamole. In the first part of the investigation, eight patients without coronary artery disease (CAD) (group 1) and 20 patients with mild angina (group 2) were studied. In the second part of the study, seven patients (group 3) with mild angina pectoris received an intravenous infusion of 0.4 microgram X kg-1 X min-1 of nitroglycerin started before surgery and gradually decreased 4 hr after extubation. In group 1, EF remained unchanged at recovery. In contrast in group 2, EF responded abnormally to recovery: EF decreased from 55% during anesthesia to 45% 3 min after extubation (P less than 0.001). Patients in group 3, who received intravenous nitroglycerin, showed no change of EF at recovery. This study demonstrates that recovery from general anesthesia causes abnormalities in left ventricular function in patients suffering from CAD. These abnormalities are prevented by prophylactic intravenous nitroglycerin.

  17. Long-term follow-up of patients with silent ischemia during exercise radionuclide angiography

    SciTech Connect

    Breitenbuecher, A.P.; Pfisterer, M.; Hoffmann, A.; Burckhardt, D. )

    1990-04-01

    A retrospective 5 year follow-up study was performed in 140 patients with unequivocal ischemia during exercise radionuclide angiography (greater than or equal to 10% decrease in left ventricular ejection fraction or greater than or equal to 5% decrease in ejection fraction together with a distinct regional wall motion abnormality). In 84 patients (60%), ischemia during radionuclide angiography was silent (silent ischemia group), whereas 56 patients experienced angina during the test (symptomatic group). Work load and antianginal medication were similar in both groups. Critical cardiac events (unstable angina, myocardial infarction, cardiac death) occurred in 27% of patients in the silent ischemia group and 16% of those in the symptomatic group (p = NS); however, myocardial infarction or death was more frequent in patients with silent ischemia (22% versus 9%; p less than 0.05). If there was additional exercise-induced ST segment depression, the rate of critical events was further increased (p less than 0.05). The difference in critical cardiac events seemed to be influenced by the higher incidence of revascularization procedures in symptomatic patients, whereas medical therapy had no similar effect. Thus, these findings suggest that patients with documented severe ischemia should undergo left heart catheterization and revascularization irrespective of symptoms to improve their prognosis.

  18. Coronary CT Angiography as a Diagnostic and Prognostic Tool: Perspectives from the SCOT-HEART Trial.

    PubMed

    Doris, Mhairi; Newby, David E

    2016-02-01

    Coronary artery disease is the leading cause of death worldwide. Many trials to date have investigated the diagnostic accuracy of coronary computed tomography angiography (CCTA) when compared to the gold standard diagnostic test, invasive coronary angiography. However, whether the use of a non-invasive anatomical test, such as CCTA, can translate into improved patient risk stratification, management and outcome has yet to be established. The Scottish COmputed Tomography of the HEART (SCOT-HEART) trial sought to address these questions and determined whether CCTA, when used in addition to standard care, could aid the diagnosis, further investigation and treatment of patients referred to the cardiology clinic with suspected angina due to coronary heart disease. In this trial, CCTA clarified the diagnosis of angina due to coronary heart disease in a quarter of patients and this led to major alterations in treatment and management that appeared to reduce the risk of subsequent coronary heart disease death or non-fatal myocardial infarction. The SCOT-Heart trial has established that CCTA is a valuable diagnostic test in patients with suspected angina pectoris due to coronary heart disease and leads to greater clarity, more focused appropriate treatments and better coronary heart disease outcomes.

  19. 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.

  20. Aortic angiography

    MedlinePlus

    ... have ever had any allergic reactions to x-ray contrast material or iodine substances If you are allergic to any medicines Which medicines you are taking (including any herbal preparations) If you have ever had any bleeding problems

  1. Catheter Angiography

    MedlinePlus

    ... in key areas of the body, including the: brain neck heart chest abdomen (such as the kidneys and ... plaque) disease in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke. identify a small aneurysm ...

  2. Computer-aided detection of pulmonary embolism in computed tomographic pulmonary angiography (CTPA): performance evaluation with independent data sets.

    PubMed

    Zhou, Chuan; Chan, Heang-Ping; Sahiner, Berkman; Hadjiiski, Lubomir M; Chughtai, Aamer; Patel, Smita; Wei, Jun; Cascade, Philip N; Kazerooni, Ella A

    2009-08-01

    The authors are developing a computer-aided detection system for pulmonary emboli (PE) in computed tomographic pulmonary angiography (CTPA) scans. The pulmonary vessel tree is extracted using a 3D expectation-maximization segmentation method based on the analysis of eigen-values of Hessian matrices at multiple scales. A parallel multiprescreening method is applied to the segmented vessels to identify volume of interests (VOIs) that contained suspicious PE. A linear discriminant analysis (LDA) classifier with feature selection is designed to reduce false positives (FPs). Features that characterize the contrast, gray level, and size of PE are extracted as input predictor variables to the LDA classifier. With the IRB approval, 59 CTPA PE cases were collected retrospectively from the patient files (UM cases). With access permission, 69 CTPA PE cases were randomly selected from the data set of the prospective investigation of pulmonary embolism diagnosis (PIOPED) II clinical trial. Extensive lung parenchymal or pleural diseases were present in 22/59 UM and 26/69 PIOPED cases. Experienced thoracic radiologists manually marked 595 and 800 PE as the reference standards in the UM and PIOPED data sets, respectively. PE occlusion of arteries ranged from 5% to 100%, with PE located from the main pulmonary artery to the subsegmental artery levels. Of the 595 PE identified in the UM cases, 245 and 350 PE were located in the subsegmental arteries and the more proximal arteries, respectively. The detection performance was assessed by free response ROC (FROC) analysis. The FROC analysis indicated that the PE detection system could achieve an overall sensitivity of 80% at 18.9 FPs/case for the PIOPED cases when the LDA classifier was trained with the UM cases. The test sensitivity with the UM cases was 80% at 22.6 FPs/cases when the LDA classifier was trained with the PIOPED cases. The detection performance depended on the arterial level where the PE was located and on the

  3. Measuring spatial effects in time to event data: a case study using months from angiography to coronary artery bypass graft (CABG).

    PubMed

    Crook, Angela M; Knorr-Held, Leonhard; Hemingway, Harry

    2003-09-30

    The application of Bayesian hierarchical models to measure spatial effects in time to event data has not been widely reported. This case study aims to estimate the effect of area of residence on waiting times to coronary artery bypass graft (CABG) and to assess the role of important individual specific covariates (age, sex and disease severity). The data involved all patients with definite coronary artery disease who were referred to one cardiothoracic unit from five contiguous health authorities covering 488 electoral wards (areas). Time to event was the waiting time in months from angiography (diagnosis) to CABG (event). A number of discrete time survival models were fitted to the data. A discrete baseline hazard was estimated by fitting waiting time non-parametrically into the models. Ward was fitted as a spatial effect using a Gaussian Markov random field prior. Individual specific covariates considered were age, sex and number of diseased vessels. The recently proposed DIC criteria was used for comparing models. Results showed a marked spatial effect on time to bypass surgery after including age, sex and disease severity in the model. Notably this spatial effect was not apparent when these covariates were not included in the model. The observed small area spatial variation in time to CABG warrants further investigation. PMID:12953290

  4. Measuring spatial effects in time to event data: a case study using months from angiography to coronary artery bypass graft (CABG).

    PubMed

    Crook, Angela M; Knorr-Held, Leonhard; Hemingway, Harry

    2003-09-30

    The application of Bayesian hierarchical models to measure spatial effects in time to event data has not been widely reported. This case study aims to estimate the effect of area of residence on waiting times to coronary artery bypass graft (CABG) and to assess the role of important individual specific covariates (age, sex and disease severity). The data involved all patients with definite coronary artery disease who were referred to one cardiothoracic unit from five contiguous health authorities covering 488 electoral wards (areas). Time to event was the waiting time in months from angiography (diagnosis) to CABG (event). A number of discrete time survival models were fitted to the data. A discrete baseline hazard was estimated by fitting waiting time non-parametrically into the models. Ward was fitted as a spatial effect using a Gaussian Markov random field prior. Individual specific covariates considered were age, sex and number of diseased vessels. The recently proposed DIC criteria was used for comparing models. Results showed a marked spatial effect on time to bypass surgery after including age, sex and disease severity in the model. Notably this spatial effect was not apparent when these covariates were not included in the model. The observed small area spatial variation in time to CABG warrants further investigation.

  5. Qualitative indices and enhancement rate of CT pulmonary angiography in patients with suspected pulmonary embolism: Comparison between test bolus and bolus-tracking methods

    PubMed Central

    Moradi, Maryam; Khalili, Babak

    2016-01-01

    Background: The aim of the present study was to assess the qualitative indices and enhancement rate of computed tomographic pulmonary angiography (CTPA) in patients with suspected pulmonary embolism using Test bolus and Bolus-tracking techniques. Materials and Methods: Fifty-two patients with suspected pulmonary embolism that passed informed consent were randomly divided in the two groups. In each group, demographic characteristics, qualitative indices, and enhancement rate of CTPA were recorded. Results: The diagnostic result obtained in majority of the participants in the two groups (88.5 % in Test bolus group vs. 73.1% in the Bolus tracking group). In the case of quantitative variables, no statistically significant differences were found between the groups (P > 0.05). The only statistically significant difference between the two groups is average of “X-ray dose”. Conclusion: The results of our study show that there is no statistically significant difference between the Bolus Tracking and Test Bolus techniques for producing more homogeneous enhancement. PMID:27403408

  6. [Evaluation of the myocardial ischemic and arrhythmogenic risk of digitalized angiography by venous route. Apropos of a comparative trial of ioxaglate and iopamidol].

    PubMed

    Baudouy, P Y; Lasry, J L; Lagneau, P; Abassade, P; Valleteau de Moulliac, M

    1988-03-01

    Cardiac tolerance to digital subtraction angiography by venous route (DSAV) was evaluated during a prospective study of a continuous series of 100 patients of both sexes investigated for various arterial diseases, and classified previously as "cardiac" and "non-cardiac". A permanent 12 lead ECE recording by sequences of 3 allowed study of ischemic and rhythmic changes provoked by randomly allocated injections of contrast media, Ioxaglate or Iopamidol. Major cardiac complications were not observed in the 98 patients studied (2 excluded), but in 32.6% auricular extrasystoles (AES) and/or ventricular extrasystoles (VES) were noted and in 19.4% a painless widening of the ST segment of 0.5 mm or more. The and ST widening were more frequent in the VES 40 patients classed as "cardiac" than in the 58 "non cardiac" (35% against 8.6%, p less than 0.01 and 37.5% against 6.9%, p less than 0.001 respectively). The two products did not differ with respect to their effect on frequency of repolarization anomalies, whereas Ioxaglate provoked more VES than Iopamidol (30% against 8%, p less than 0.02). It is concluded that cardiac tolerance to DSAV is good, but that the frequency of VES and painless repolarization ischemic disorders observed, even with only weakly hypertonic contrast media of non ionic type, suggests that their indications be limited and that certain precautions are necessary in cardiac patients.

  7. Random quantum operations

    NASA Astrophysics Data System (ADS)

    Bruzda, Wojciech; Cappellini, Valerio; Sommers, Hans-Jürgen; Życzkowski, Karol

    2009-01-01

    We define a natural ensemble of trace preserving, completely positive quantum maps and present algorithms to generate them at random. Spectral properties of the superoperator Φ associated with a given quantum map are investigated and a quantum analogue of the Frobenius-Perron theorem is proved. We derive a general formula for the density of eigenvalues of Φ and show the connection with the Ginibre ensemble of real non-symmetric random matrices. Numerical investigations of the spectral gap imply that a generic state of the system iterated several times by a fixed generic map converges exponentially to an invariant state.

  8. Random walks on networks

    NASA Astrophysics Data System (ADS)

    Donnelly, Isaac

    Random walks on lattices are a well used model for diffusion on continuum. They have been to model subdiffusive systems, systems with forcing and reactions as well as a combination of the three. We extend the traditional random walk framework to the network to obtain novel results. As an example due to the small graph diameter, the early time behaviour of subdiffusive dynamics dominates the observed system which has implications for models of the brain or airline networks. I would like to thank the Australian American Fulbright Association.

  9. Comparison of computed tomography pulmonary angiography and point-of-care tests for pulmonary thromboembolism diagnosis in dogs

    PubMed Central

    Goggs, R; Chan, D L; Benigni, L; Hirst, C; Kellett-Gregory, L; Fuentes, V L

    2014-01-01

    Objectives To evaluate the feasibility of CT pulmonary angiography for identification of naturally occurring pulmonary thromboembolism in dogs using predefined diagnostic criteria and to assess the ability of echocardiography, cardiac troponins, D-dimers and kaolin-activated thromboelastography to predict the presence of pulmonary thromboembolism in dogs. Methods Twelve dogs with immune-mediated haemolytic anaemia and evidence of respiratory distress were prospectively evaluated. Dogs were sedated immediately before CT pulmonary angiography using intravenous butorphanol. Spiral CT pulmonary angiography was performed with a 16 detector-row CT scanner using a pressure injector to infuse contrast media through peripheral intravenous catheters. Pulmonary thromboembolism was diagnosed using predefined criteria. Contemporaneous tests included echocardiography, arterial blood gas analysis, kaolin-activated thromboelastography, D-dimers and cardiac troponins. Results Based on predefined criteria, four dogs were classified as pulmonary thromboembolism positive, three dogs were suspected to have pulmonary thromboembolism and the remaining five dogs had negative scans. The four dogs identified with pulmonary thromboembolism all had discrete filling defects in main or lobar pulmonary arteries. None of the contemporaneous tests was discriminant for pulmonary thromboembolism diagnosis, although the small sample size was limiting. Clinical Significance CT pulmonary angiography can be successfully performed in dogs under sedation, even in at-risk patients with respiratory distress and can both confirm and rule out pulmonary thromboembolism in dogs. PMID:24521253

  10. High-Efficiency SPECT MPI: Comparison of Automated Quantification, Visual Interpretation, and Coronary Angiography

    PubMed Central

    Duvall, W. Lane; Slomka, Piotr J.; Gerlach, Jim R.; Sweeny, Joseph M.; Baber, Usman; Croft, Lori B.; Guma, Krista A.; George, Titus; Henzlova, Milena J.

    2013-01-01

    Background Recently introduced high-efficiency (HE) SPECT cameras with solid-state CZT detectors have been shown to decrease imaging time and reduce radiation exposure to patients. An automated, computer derived quantification of HE MPI has been shown to correlate well with coronary angiography on one HE SPECT camera system (D-SPECT), but has not been compared to visual interpretation on any of the HE SPECT platforms. Methods Patients undergoing a clinically indicated Tc-99m sestamibi HE SPECT (GE Discovery 530c with supine and prone imaging) study over a one year period followed by a coronary angiogram within 2 months were included. Only patients with a history of CABG surgery were excluded. Both MPI studies and coronary angiograms were reinterpreted by blinded readers. One hundred and twenty two very low (risk of CAD < 5%) or low (risk of CAD < 10%) likelihood subjects with normal myocardial perfusion were used to create normal reference limits. Computer derived quantification of the total perfusion deficit (TPD) at stress and rest was obtained with QPS software. The visual and automated MPI quantification were compared to coronary angiography (≥ 70% luminal stenosis) by receiver operating curve (ROC) analysis. Results Of the 3,111 patients who underwent HE SPECT over a one year period, 160 patients qualified for the correlation study (66% male, 52% with a history of CAD). The ROC area under the curve (AUC) was similar for both the automated and visual interpretations using both supine only and combined supine and prone images (0.69-0.74). Using thresholds determined from sensitivity and specificity curves, the automated reads showed higher specificity (59-67% versus 27-60%) and lower sensitivity (71-72% versus 79-93%) than the visual reads. By including prone images sensitivity decreased slightly but specificity increased for both. By excluding patients with known CAD and cardiomyopathies, AUC and specificity increased for both techniques (0.72-0.82). The use

  11. Intravenous Contrast Material Administration at High-pitch Dual-source CT Coronary Angiography: Bolus-tracking Technique with Shortened Time of Respiratory Instruction Versus Test Bolus Technique.

    PubMed

    Sun, Kai; Liu, Guo-Rong; Li, Yue-Chun; Han, Rui-Juan; Cui, Li-Fang; Ma, Li-Jun; Li, Li-Gang; Li, Chang-Yong

    2013-01-01

    Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv, P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.

  12. SU-E-I-25: Quantification of Coronary Artery Cross-Sectional Area in CT Angiography Using Integrated Density: A Simulation Study

    SciTech Connect

    Johnson, T; Ding, H; Lipinski, J; Molloi, S

    2015-06-15

    Purpose: To develop a physics-based model for accurate quantification of the cross-sectional area (CSA) of coronary arteries in CT angiography by measuring the integrated density to account for the partial volume effect. Methods: In this technique the integrated density of the object as compared with its local background is measured to account for the partial volume effect. Normal vessels were simulated as circles with diameters in the range of 0.1–3mm. Diseased vessels were simulated as 2, 3, and 4mm diameter vessels with 10–90% area stenosis, created by inserting circular plaques. A simplified two material model was used with the lumen as 8mg/ml Iodine and background as lipid. The contrast-to-noise ratio between lumen and background was approximately 26. Linear fits to the known CSA were calculated. The precision and accuracy of the measurement were quantified using the root-mean-square fit deviations (RMSD) and errors to the known CSA (RMSE). Results compared to manual segmentation of the vessel lumen. To assess the impact of random variations, coefficients of variation (CV) from 10 simulations for each vessel were computed to determine reliability. Measurements with CVs less than 10% were considered reliable. Results: For normal vessels, the precision and accuracy of the integrated density technique were 0.12mm{sup 2} and 0.28mm{sup 2}, respectively. The corresponding results for manual segmentation were 0.27mm{sup 2} and 0.43mm{sup 2}. For diseased vessels, the precision and accuracy of the integrated density technique were 0.14mm{sup 2} and 0.19mm{sup 2}. Corresponding results for manual segmentation were 0.42mm{sup 2} and 0.71mm{sup 2}. Reliable CSAs were obtained for normal vessels with diameters larger than 1 mm and for diseased vessels with area as low as 1.26mm2. Conclusion: The CSA based on integrated density showed improved precision and accuracy as compared with manual segmentation in simulation. These results indicate the potential of using

  13. Randomness Of Amoeba Movements

    NASA Astrophysics Data System (ADS)

    Hashiguchi, S.; Khadijah, Siti; Kuwajima, T.; Ohki, M.; Tacano, M.; Sikula, J.

    2005-11-01

    Movements of amoebas were automatically traced using the difference between two successive frames of the microscopic movie. It was observed that the movements were almost random in that the directions and the magnitudes of the successive two steps are not correlated, and that the distance from the origin was proportional to the square root of the step number.

  14. Random lasers ensnared

    NASA Astrophysics Data System (ADS)

    Leonetti, Marco; López, Cefe

    2012-06-01

    A random laser is formed by a haphazard assembly of nondescript optical scatters with optical gain. Multiple light scattering replaces the optical cavity of traditional lasers and the interplay between gain, scattering and size determines its unique properties. Random lasers studied till recently, consisted of irregularly shaped or polydisperse scatters, with some average scattering strength constant across the gain frequency band. Photonic glasses can sustain scattering resonances that can be placed in the gain window, since they are formed by monodisperse spheres [1]. The unique resonant scattering of this novel material allows controlling the lasing color via the diameter of the particles and their refractive index. Thus a random laser with a priori set lasing peak can be designed [2]. A special pumping scheme that enables to select the number of activated modes in a random laser permits to prepare RLs in two distinct regimes by controlling directionality through the shape of the pump [3]. When pumping is essentially unidirectional, few (barely interacting) modes are turned on that show as sharp, uncorrelated peaks in the spectrum. By increasing angular span of the pump beams, many resonances intervene generating a smooth emission spectrum with a high degree of correlation, and shorter lifetime. These are signs of a phaselocking transition, in which phases are clamped together so that modes oscillate synchronously.

  15. Generating "Random" Integers

    ERIC Educational Resources Information Center

    Griffiths, Martin

    2011-01-01

    One of the author's undergraduate students recently asked him whether it was possible to generate a random positive integer. After some thought, the author realised that there were plenty of interesting mathematical ideas inherent in her question. So much so in fact, that the author decided to organise a workshop, open both to undergraduates and…

  16. Contouring randomly spaced data

    NASA Technical Reports Server (NTRS)

    Kibler, J. F.; Morris, W. D.; Hamm, R. W.

    1977-01-01

    Computer program using triangulation contouring technique contours data points too numerous to fit into rectangular grid. Using random access procedures, program can handle up to 56,000 data points and provides up to 20 contour intervals for multiple number of parameters.

  17. Uniform random number generators

    NASA Technical Reports Server (NTRS)

    Farr, W. R.

    1971-01-01

    Methods are presented for the generation of random numbers with uniform and normal distributions. Subprogram listings of Fortran generators for the Univac 1108, SDS 930, and CDC 3200 digital computers are also included. The generators are of the mixed multiplicative type, and the mathematical method employed is that of Marsaglia and Bray.

  18. Randomization and sampling issues

    USGS Publications Warehouse

    Geissler, P.H.

    1996-01-01

    The need for randomly selected routes and other sampling issues have been debated by the Amphibian electronic discussion group. Many excellent comments have been made, pro and con, but we have not reached consensus yet. This paper brings those comments together and attempts a synthesis. I hope that the resulting discussion will bring us closer to a consensus.

  19. On Random Numbers and Design

    ERIC Educational Resources Information Center

    Ben-Ari, Morechai

    2004-01-01

    The term "random" is frequently used in discussion of the theory of evolution, even though the mathematical concept of randomness is problematic and of little relevance in the theory. Therefore, since the core concept of the theory of evolution is the non-random process of natural selection, the term random should not be used in teaching the…

  20. [Comparative evaluation of ultrasonography, computerized tomography, angiography and lipiodol CT in defining extent of hepatocarcinoma. A multicenter study].

    PubMed

    Dalla Palma, L; Pozzi Mucelli, R; Sponza, M; Bartolozzi, C; De Santis, M; Gandini, G; Mannella, P; Matricardi, L; Rossi, C; Simonetti, G

    1995-03-01

    The authors report the results of a multicentric trial on hepatocellular carcinoma (HCC) patients, whose lesions were confirmed with biopsy or by high (> 400 ng/ml) alpha-fetoprotein levels. The series consisted of 149 patients examined in 8 different centers and submitted to ultrasonography (US), Computed Tomography (CT) before and after contrast agent administration, angiography and Lipiodol CT. According to lesion size and number, the patients were divided with each imaging modality into three groups: a) group 1: unifocal HCC < 5 cm diameter; b) group 2: multifocal HCC with 2-3 nodules and/or tumor mass < 80 ml; c) multifocal HCC with more than 3 nodules (with total tumor mass not exceeding 40% of liver volume) or with total tumor mass > 80 ml. In 77 patients all the examinations were available for comparison. US and CT diagnosed more patients as belonging to group 1 than angiography and Lipiodol CT, while more patients were classified as groups 2 and 3 with angiography and Lipiodol CT, meaning that US and CT may understage some HCC cases (about 15%) because they show a lower number of nodules. This observation was confirmed by the direct comparison between US and Lipiodol CT (in 114 patients), CT and Lipiodol CT (in 103 patients) and angiography and Lipiodol CT (in 116 patients). US and Lipiodol CT were in disagreement in 18 cases, CT and Lipiodol CT in 16 cases and angiography and Lipiodol CT in 13 cases. In most of these cases, Lipiodol CT showed more lesions than the other techniques. The size of the undetected lesions was small, ranging few mm to 2 cm in nearly all cases. To conclude, the results of this multicentric trial show that Lipiodol CT is a fundamental tool to evaluate HCC extent. In contrast, conventional CT appeared not to add any significant piece of information and can therefore be excluded from the diagnostic protocol of HCC.

  1. [The correlation between measurements performed by intravascular echography and quantitative digital angiography in large- and small-caliber arteries].

    PubMed

    Zamorano, J; Macaya, C; Alfonso, F; Goicolea, J; Iñíguez, A; Hernández-Antolín, R A; Ge, J; Zarco, P; Erbel, R; Meyer, J

    1992-04-01

    Intravascular ultrasound is a new promising technique that appears as a very useful complement to standard angiography in the study of atherosclerosis. Specifically, intravascular ultrasound provides by itself, information of great value concerning vessel wall characteristics. Nevertheless, before taking any decision with the results provided by this new technique, we must validate this information with that provided by other more conventional techniques like standard angiography. Accordingly, we have analyzed in 25 patients, 50 images of the abdominal aorta and 77 images of the coronary arteries taken from arterial segments free of atherosclerotic involvement. With the use of a calibrated small grid located over the patient's thorax, we have analyzed "in the same points" the images obtained with intravascular ultrasound and those provided by contrast angiography using a quantitative angiographic analysis. In the abdominal aorta the vessel diameter measured by intravascular ultrasound and angiography was 17.8 +/- 0.39 mm vs 18.6 +/- 0.42 mm (NS), whereas in the coronary arteries it was 2.76 +/- 0.39 mm vs 2.98 +/- 0.37 mm (NS), respectively. The correlation between both techniques was good for both types of arteries (r = 0.93 in the abdominal aorta and r = 0.87 in the coronary arteries). We conclude, that in our experience and with the methodology used, there is a good correlation between the measurements of the vessel diameters obtained by both intravascular ultrasound and digital angiography in arteries of different sizes, being the correlation even better in large arteries.

  2. Congenital coronary anomalies in adults: comparison of anatomic course visualization by catheter angiography and electron beam CT.

    PubMed

    Memisoglu, Esat; Hobikoglu, Gultekin; Tepe, M Savas; Norgaz, Tugrul; Bilsel, Tuba

    2005-09-01

    The objective of this study was to compare the anatomic course of anomalous coronary arteries by axial and three-dimensional volume-rendered electron beam computed tomography (EBCT) angiography and X-ray catheter angiography (CAG). We performed a blinded study where patients who previously underwent CAG with (n = 14) and without (n = 14; age- and gender-matched controls) anomalous coronary anatomy were studied with EBCT coronary angiography. Forty to 50 EKG-triggered 3 mm overlapping axial slices were acquired with 2 mm table movement within one breath hold during the i.v. injection of 140 cc of nonionic iodinated contrast (4 ml/sec). The axial source images and volume-rendered three-dimensional reconstructions were evaluated for the presence, type, and course of coronary anomalies and the results were compared to those of CAG. All normal and anomalous coronary arteries were identified by both modalities in all subjects. Identified anomalies include single coronary artery (n = 3), left-sided right coronary artery (n = 3), right-sided left main coronary artery (n = 3), anterior descending coronary artery (n = 2), circumflex coronary artery (n = 2), and separate left-sided ostia for left anterior descending and circumflex coronary arteries (n = 1). In five cases, there was discrepancy in the course of the anomalous vessels between the two modalities. Consensus reading among cardiologist and radiologists favored the interpretation of EBCT over catheter angiography. Noninvasive EBCT coronary angiography compares well with CAG in identifying anomalous coronary arteries and may provide confirmatory evaluation of their precise anatomic relationships to the heart and great vessels. PMID:16097013

  3. Trends in Coronary Angiography, Revascularization, and Outcomes of Cardiogenic Shock Complicating Non-ST-Elevation Myocardial Infarction.

    PubMed

    Kolte, Dhaval; Khera, Sahil; Dabhadkar, Kaustubh C; Agarwal, Shikhar; Aronow, Wilbert S; Timmermans, Robert; Jain, Diwakar; Cooper, Howard A; Frishman, William H; Menon, Venu; Bhatt, Deepak L; Abbott, J Dawn; Fonarow, Gregg C; Panza, Julio A

    2016-01-01

    Early revascularization is the mainstay of treatment for cardiogenic shock (CS) complicating acute myocardial infarction. However, data on the contemporary trends in management and outcomes of CS complicating non-ST-elevation myocardial infarction (NSTEMI) are limited. We used the 2006 to 2012 Nationwide Inpatient Sample databases to identify patients aged ≥ 18 years with NSTEMI with or without CS. Temporal trends and differences in coronary angiography, revascularization, and outcomes were analyzed. Of 2,191,772 patients with NSTEMI, 53,800 (2.5%) had a diagnosis of CS. From 2006 to 2012, coronary angiography rates increased from 53.6% to 60.4% in patients with NSTEMI with CS (ptrend <0.001). Among patients who underwent coronary angiography, revascularization rates were significantly higher in patients with CS versus without CS (72.5% vs 62.6%, p <0.001). Patients with NSTEMI with CS had significantly higher risk-adjusted in-hospital mortality (odds ratio 10.09, 95% confidence interval 9.88 to 10.32) as compared to those without CS. In patients with CS, an invasive strategy was associated with lower risk-adjusted in-hospital mortality (odds ratio 0.43, 95% confidence interval 0.42 to 0.45). Risk-adjusted in-hospital mortality, length of stay, and total hospital costs decreased over the study period in patients with and without CS (ptrend <0.001). In conclusion, we observed an increasing trend in coronary angiography and decreasing trend in in-hospital mortality, length of stay, and total hospital costs in patients with NSTEMI with and without CS. Despite these positive trends, overall coronary angiography and revascularization rates remain less than optimal and in-hospital mortality unacceptably high in patients with NSTEMI and CS.

  4. Prediction of cardiac events after uncomplicated myocardial infarction: a prospective study comparing predischarge exercise thallium-201 scintigraphy and coronary angiography

    SciTech Connect

    Gibson, R.S.; Watson, D.D.; Craddock, G.B.; Crampton, R.S.; Kaiser, D.L.; Denny, M.J.; Beller, G.A.

    1983-08-01

    The ability of predischarge quantitative exercise thallium-201 (/sup 201/T1) scintigraphy to predict future cardiac events was evaluated prospectively in 140 consecutive patients with uncomplicated acute myocardial infarction; the results were compared with those of submaximal exercise treadmill testing and coronary angiography. High risk was assigned if scintigraphy detected /sup 201/T1 defects in more than one discrete vascular region, redistribution, or increased lung uptake, if exercise testing caused ST segment depression greater than or equal to 1 mm or angina or if angiography revealed multivessel disease. Low risk was designated if scintigraphy detected a single-region defect, no redistribution, or no increase in lung uptake, if exercise testing caused no ST segment depression or angina, or if angiography revealed single-vessel disease or no disease. By 15 +/- 12 months, 50 patients had experienced a cardiac event; seven died (five suddenly), nine suffered recurrent myocardial infarction, and 34 developed severe class III or IV angina pectoris. Compared with that of patients at low risk, the cumulative probability of a cardiac event was greater in high-risk patients identified by scintigraphy, exercise testing, or angiography. Scintigraphy predicted low-risk status better than exercise testing or angiography. Each predicted mortality with equal accuracy. These results indicate that (1) submaximal exercise /sup 201/T1 scintigraphy can distinguish high- and low-risk groups after uncomplicated acute myocardial infarction before hospital discharge; (2) /sup 201/T1 defects in more than one discrete vascular region, presence of delayed redistribution, or increased lung thallium uptake are more sensitive predictors of subsequent cardiac events than ST segment depression, angina, or extent of angiographic disease; and (3) low-risk patients are best identified by a single-region /sup 201/T1 defect without redistribution and no increased lung uptake.

  5. Improved motion contrast and processing efficiency in OCT angiography using complex-correlation algorithm

    NASA Astrophysics Data System (ADS)

    Guo, Li; Li, Pei; Pan, Cong; Liao, Rujia; Cheng, Yuxuan; Hu, Weiwei; Chen, Zhong; Ding, Zhihua; Li, Peng

    2016-02-01

    The complex-based OCT angiography (Angio-OCT) offers high motion contrast by combining both the intensity and phase information. However, due to involuntary bulk tissue motions, complex-valued OCT raw data are processed sequentially with different algorithms for correcting bulk image shifts (BISs), compensating global phase fluctuations (GPFs) and extracting flow signals. Such a complicated procedure results in massive computational load. To mitigate such a problem, in this work, we present an inter-frame complex-correlation (CC) algorithm. The CC algorithm is suitable for parallel processing of both flow signal extraction and BIS correction, and it does not need GPF compensation. This method provides high processing efficiency and shows superiority in motion contrast. The feasibility and performance of the proposed CC algorithm is demonstrated using both flow phantom and live animal experiments.

  6. [Affine transformation-based automatic registration for peripheral digital subtraction angiography (DSA)].

    PubMed

    Kong, Gang; Dai, Dao-Qing; Zou, Lu-Min

    2008-07-01

    In order to remove the artifacts of peripheral digital subtraction angiography (DSA), an affine transformation-based automatic image registration algorithm is introduced here. The whole process is described as follows: First, rectangle feature templates are constructed with their centers of the extracted Harris corners in the mask, and motion vectors of the central feature points are estimated using template matching technology with the similarity measure of maximum histogram energy. And then the optimal parameters of the affine transformation are calculated with the matrix singular value decomposition (SVD) method. Finally, bilinear intensity interpolation is taken to the mask according to the specific affine transformation. More than 30 peripheral DSA registrations are performed with the presented algorithm, and as the result, moving artifacts of the images are removed with sub-pixel precision, and the time consumption is less enough to satisfy the clinical requirements. Experimental results show the efficiency and robustness of the algorithm.

  7. A 1200 element detector system for synchrotron-based coronary angiography

    SciTech Connect

    Thompson, A.C.; Lavender, W.M.; Rubenstein, E.; Giacomini, J.C.; Rosso, V.; Schulze, C.; Chapman, D.; Thomlinson, W.

    1993-08-23

    A 1200 channel Si(Li) detector system has been developed for transvenous coronary angiography experiments using synchrotron radiation. It is part of the synchrotron medical imaging facility at the National Synchrotron Light Source. The detector is made from a single crystal of lithium-drifted silicon with an active area 150 mm long {times} 11 mm high {times} 5 mm thick. The elements are arranged in two parallel rows of 600 elements with a center-to-center spacing of 0.25 mm. All 1200 elements are read out simultaneously every 4 ms. A Intel 80486 based computer with a high speed digital signal processing interface is used to control the beamline hardware and to acquire a series of images. The signal-to-noise, linearity and resolution of the system have been measured. Human images have been taken with this system.

  8. CT coronary angiography: new risks for low-risk chest pain.

    PubMed

    Radecki, Ryan Patrick

    2013-10-01

    Widespread conservative management of low-risk chest pain has motivated the development of a rapid triage strategy based on CT coronary angiography (CTCA) in the Emergency Department (ED). Recently, three prominent trials using this technology in the ED setting have presented results in support of its routine use. However, these studies fail to show the incremental prognostic value of CTCA over clinical and biomarker-based risk-stratification strategies, demonstrate additional downstream costs and interventions, and result in multiple harms associated with radio-contrast and radiation exposure. Observing the widespread overdiagnosis of pulmonary embolism following availability of CT pulmonary angiogram as a practice pattern parallel, CTCA use for low-risk chest pain in the ED should be advanced only with caution.

  9. From 3D to 4D: Integration of temporal information into CT angiography studies.

    PubMed

    Haubenreisser, Holger; Bigdeli, Amir; Meyer, Mathias; Kremer, Thomas; Riester, Thomas; Kneser, Ulrich; Schoenberg, Stefan O; Henzler, Thomas

    2015-12-01

    CT angiography is the current clinical standard for the imaging many vascular illnesses. This is traditionally done with a single arterial contrast phase. However, advances in CT technology allow for a dynamic acquisition of the contrast bolus, thus adding temporal information to the examination. The aim of this article is to highlight the clinical possibilities of dynamic CTA using 2 examples. The accuracy of the detection and quantification of stenosis in patients with peripheral arterial occlusive disease, especially in stadium III and IV, is significantly improved when performing dynamic CTA examinations. The post-interventional follow-up of examinations of EVAR benefit from dynamic information, allowing for a higher sensitivity and specificity, as well as allowing more accurate classification of potential endoleaks. The described radiation dose for these dynamic examinations is low, but this can be further optimized by using lower tube voltages. There are a multitude of applications for dynamic CTA that need to be further explored in future studies.

  10. Intravenous digital subtraction angiography of the intracranial veins and dural sinuses

    SciTech Connect

    Modic, M.T.; Weinstein, M.A.; Starnes, D.L.; Kinney, S.E.; Duchesneau, P.M.

    1983-02-01

    The intravenous digital subtraction angiographic (IV DSA) examinations of 100 patients studied for abnormalities unrelated to the intracranial venous structures were reviewed to determine and tabulate the frequency and adequacy of visualizaton of the venous drainage of the brain. In addition, 25 patients were specifically evaluated with IV DSA for abnormalities of the intracranial veins and sinuses. Conditions studied included: compression, displacement, or occlusion of the venous structures; carotid-cavernous sinus fistulas; tumors of the base of the skull, including glomus tumors; and normal variations in the position, size, and course of the venous structures. When combined with computed tomography, IV DSA is usually of sufficient quality to replace conventional angiography in the evaluation of the larger venous structures of the head and neck.

  11. Ultrahigh-Speed Swept-Source OCT Angiography in Exudative AMD

    PubMed Central

    Moult, Eric; Choi, WooJhon; Waheed, Nadia K.; Adhi, Mehreen; Lee, ByungKun; Lu, Chen D.; Jayaraman, Vijaysekhar; Potsaid, Benjamin; Rosenfeld, Philip J.; Duker, Jay S.; Fujimoto, James G.

    2016-01-01

    Background and Objective To investigate the potential of ultrahigh-speed swept-source optical coherence tomography angiography (OCTA) to visualize retinal and choroidal vascular changes in patients with exudative age-related macular degeneration (AMD). Patients and Methods Observational, prospective cross-sectional study. An ultrahigh-speed swept-source prototype was used to perform OCTA of the retinal and choriocapillaris microvasculature in 63 eyes of 32 healthy controls and 19 eyes of 15 patients with exudative AMD. Main outcome measure: qualitative comparison of the retinal and choriocapillaris microvasculature in the two groups. Results Choroidal neovascularization (CNV) was clearly visualized in 16 of the 19 eyes with exudative AMD, located above regions of severe choriocapillaris alteration. In 14 of these eyes, the CNV lesions were surrounded by regions of choriocapillaris alteration. Conclusion OCTA may offer noninvasive monitoring of the retinal and choriocapillaris microvasculature in patients with CNV, which may assist in diagnosis and monitoring. PMID:25423628

  12. 3D reconstruction of coronary arteries using frequency domain optical coherence tomography images and biplane angiography.

    PubMed

    Athanasiou, L S; Bourantas, C V; Siogkas, P K; Sakellarios, A I; Exarchos, T P; Naka, K K; Papafaklis, M I; Michalis, L K; Prati, F; Fotiadis, D I

    2012-01-01

    The aim of this study is to describe a new method for three-dimensional (3D) reconstruction of coronary arteries using Frequency Domain Optical Coherence Tomography (FD-OCT) images. The rationale is to fuse the information about the curvature of the artery, derived from biplane angiographies, with the information regarding the lumen wall, which is produced from the FD-OCT examination. The method is based on a three step approach. In the first step the lumen borders in FD-OCT images are detected. In the second step a 3D curve is produced using the center line of the vessel from the two biplane projections. Finally in the third step the detected lumen borders are placed perpendicularly onto the path based on the centroid of each lumen border. The result is a 3D reconstructed artery produced by all the lumen borders of the FD-OCT pullback representing the 3D arterial geometry of the vessel.

  13. RAPID COMMUNICATION: First human transvenous coronary angiography at the European Synchrotron Radiation Facility

    NASA Astrophysics Data System (ADS)

    Elleaume, H.; Fiedler, S.; Estève, F.; Bertrand, B.; Charvet, A. M.; Berkvens, P.; Berruyer, G.; Brochard, T.; LeDuc, G.; Nemoz, C.; Renier, M.; Suortti, P.; Thomlinson, W.; LeBas, J. F.

    2000-09-01

    The first operation of the European Synchrotron Radiation Facility (ESRF) medical beamline is reported in this paper. The goal of the angiography project is to develop a reduced risk imaging technique, which can be used to follow up patients after coronary intervention. After the intravenous injection of a contrast agent (iodine) two images are produced with monochromatic beams, bracketing the iodine K-edge. The logarithmic subtraction of the two measurements results in an iodine-enhanced image, which can be precisely quantified. A research protocol has been designed to evaluate the performances of this method in comparison with the conventional technique. Patients included in the protocol have previously undergone angioplasty. If a re-stenosis is suspected, the patient is imaged both at the ESRF and at the hospital with the conventional technique, within the next few days. This paper reports the results obtained with the first patients. To date, eight patients have been imaged and excellent image quality was obtained.

  14. Split-spectrum amplitude-decorrelation angiography with optical coherence tomography

    PubMed Central

    Jia, Yali; Tan, Ou; Tokayer, Jason; Potsaid, Benjamin; Wang, Yimin; Liu, Jonathan J.; Kraus, Martin F.; Subhash, Hrebesh; Fujimoto, James G.; Hornegger, Joachim; Huang, David

    2012-01-01

    Amplitude decorrelation measurement is sensitive to transverse flow and immune to phase noise in comparison to Doppler and other phase-based approaches. However, the high axial resolution of OCT makes it very sensitive to the pulsatile bulk motion noise in the axial direction. To overcome this limitation, we developed split-spectrum amplitude-decorrelation angiography (SSADA) to improve the signal-to-noise ratio (SNR) of flow detection. The full OCT spectrum was split into several narrower bands. Inter-B-scan decorrelation was computed using the spectral bands separately and then averaged. The SSADA algorithm was tested on in vivo images of the human macula and optic nerve head. It significantly improved both SNR for flow detection and connectivity of microvascular network when compared to other amplitude-decorrelation algorithms. PMID:22418228

  15. Model based LV-reconstruction in bi-plane x-ray angiography

    NASA Astrophysics Data System (ADS)

    Backfrieder, Werner; Carpella, Martin; Swoboda, Roland; Steinwender, Clemens; Gabriel, Christian; Leisch, Franz

    2005-04-01

    Interventional x-ray angiography is state of the art in diagnosis and therapy of severe diseases of the cardiovascular system. Diagnosis is based on contrast enhanced dynamic projection images of the left ventricle. A new model based algorithm for three dimensional reconstruction of the left ventricle from bi-planar angiograms was developed. Parametric super ellipses are deformed until their projection profiles optimally fit measured ventricular projections. Deformation is controlled by a simplex optimization procedure. A resulting optimized parameter set builds the initial guess for neighboring slices. A three dimensional surface model of the ventricle is built from stacked contours. The accuracy of the algorithm has been tested with mathematical phantom data and clinical data. Results show conformance with provided projection data and high convergence speed makes the algorithm useful for clinical application. Fully three dimensional reconstruction of the left ventricle has a high potential for improvements of clinical findings in interventional cardiology.

  16. Automatic segmentation of vertebral arteries in CT angiography using combined circular and cylindrical model fitting

    NASA Astrophysics Data System (ADS)

    Lee, Min Jin; Hong, Helen; Chung, Jin Wook

    2014-03-01

    We propose an automatic vessel segmentation method of vertebral arteries in CT angiography using combined circular and cylindrical model fitting. First, to generate multi-segmented volumes, whole volume is automatically divided into four segments by anatomical properties of bone structures along z-axis of head and neck. To define an optimal volume circumscribing vertebral arteries, anterior-posterior bounding and side boundaries are defined as initial extracted vessel region. Second, the initial vessel candidates are tracked using circular model fitting. Since boundaries of the vertebral arteries are ambiguous in case the arteries pass through the transverse foramen in the cervical vertebra, the circle model is extended along z-axis to cylinder model for considering additional vessel information of neighboring slices. Finally, the boundaries of the vertebral arteries are detected using graph-cut optimization. From the experiments, the proposed method provides accurate results without bone artifacts and eroded vessels in the cervical vertebra.

  17. Magnetic resonance angiography evidence of vasospasm in children with suspected acute hemiplegic migraine.

    PubMed

    Safier, Robert; Cleves-Bayon, Catalina; Vaisleib, Inna; Siddiqui, Ali; Zuccoli, Giulio

    2014-06-01

    Hemiplegic migraine is a rare subtype of migraine that is differentiated by motor weakness in the aura phase. The purpose of this case series was to examine the magnetic resonance angiogram findings of patients suffering from suspected acute hemiplegic migraine. This was a retrospective institutional board review protocol study of 8 patients. All patients received full brain magnetic resonance imaging under a 1.5-T magnet. The scans were subsequently evaluated by a neuroradiologist and 2 neurologists who were blinded to the study. The magnetic resonance angiogram findings of this study showed the presence of vasospasm within the intracranial vasculature during suspected acute hemiplegic migraine. This case series suggests that routine use of magnetic resonance angiography might be beneficial in both managing patients with acute hemiplegic migraine and helping to further understand the pathophysiology of this complicated disease process.

  18. Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Diagnosis with CT Angiography

    PubMed Central

    Oncel, Guray; Oncel, Dilek

    2013-01-01

    Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly. It is associated with early infant mortality and sudden death in adults. Traditionally, ALCAPA has been diagnosed by angiography or autopsy; however, the development of cardiac computed tomography (CT) and magnetic resonance imaging (MRI) has allowed noninvasive evaluation of the coronary anatomy by direct visualization of the origin of the left coronary artery (LCA) from the pulmonary artery. We report a case of 10-year-old girl who has been on follow up for dilated cardiomyopathy for 4 years. The definitive diagnosis of ALCAPA is reached by multislice computed tomography (MSCT). The MSCT scan showed an anomalous origin of LCA from the pulmonary trunk, with a tortuous and dilated right coronary artery and right-to-left collateralization. Consequently, the patient was successfully treated with surgery. PMID:23607073

  19. The evaluation of ischemic heart disease using thallium-210 with comments on radionuclide angiography

    SciTech Connect

    Leppo, J.A.; Scheuer, J.; Pohost, G.M.; Freeman, L.M.; Strauss, H.W.

    1980-04-01

    Coronary artery disease causing myocardial ischemia and infarction is the leading cause of death in America. Methods that can be used to diagnose and follow the response to therapy of coronary artery disease or its effect on myocardial ischemia should help control the morbidity and mortality of ischemic heart disease. The use of ECG monitoring is less sensitive and specific for ischemia than thallium (TI) imaging or the use of radionuclide angiography (RNA). In large patient populations, the findings of a positive ECG and TI or RNA study will be highly predictive for the presence of coronary artery disease, while negative test results make the disease unlikely. A combined approach to the patient with possible ischemic heart disease is presented.

  20. Non-iatrogenic trauma of the coronary arteries and myocardium: Contribution of angiography

    SciTech Connect

    Gaspard, P.; Clermont, A.; Villard, J.; Amiel, M.

    1983-04-01

    Six patients with coronary and myocardial trauma had selective coronary arteriography and left ventriculography. Of these, three patients with penetrating cardiac trauma presented with an occlusion of one coronary artery, including one fistula. Of three patients with blunt chest trauma, normal coronary arteries were observed in one patient, and obstruction of one artery in another; repeat coronary arteriography showed resolution of the previous obstruction in one patient. A review of the last 15 years of experience summarizes 38 angiography reports after coronary artery trauma. An analysis of the angiographic aspect of coronary artery damage is considered as an aid to understanding the traumatic lesion, its causes and its manifestations under the conditions of total or partial parietal damage of the artery, or parietal integrity.