1,355 results match your criteria angiography volumetric

Volumetric Three-Dimensional Optical Coherence Tomography Angiography of Retinal Neovascularization in Proliferative Diabetic Retinopathy.

Retin Cases Brief Rep 2021 Jul 22. Epub 2021 Jul 22.

Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. Department of Ophthalmology, National Hospital Organization, Kyushu Medical Center, Fukuoka, Japan. Canon Inc. Tokyo, Japan.

Purpose: To evaluate structural and angiographic neovascularization in patients with proliferative diabetic retinopathy (PDR) using volumetric three-dimensional optical coherence tomography angiography (OCTA).

Methods: This prospective, observational cross-sectional study included 29 eyes of 27 patients with PDR. The angiogenic structure, feeding vessel (epicenter), flow volume, and flow volume density (FVD) of the neovasculatures were evaluated using three-dimensional OCTA imaging. Read More

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Deep-learning-based motion correction in OCT angiography.

J Biophotonics 2021 Jul 20:e202100097. Epub 2021 Jul 20.

Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA.

Optical coherence tomography angiography (OCTA) is a widely applied tool to image microvascular networks with high spatial resolution and sensitivity. Due to limited imaging speed, the artifacts caused by tissue motion can severely compromise visualization of the microvascular networks and quantification of OCTA images. In this paper, we propose a deep-learning-based framework to effectively correct motion artifacts and retrieve microvascular architectures. Read More

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Correlation between CT-derived cardiac chamber volume, myocardial injury and mortality in acute pulmonary embolism.

Thromb Res 2021 Jul 9;205:63-69. Epub 2021 Jul 9.

Department of Radiology, Tel Aviv Medical Center, Tel Aviv, Israel.

Introduction: The release of troponin in patients with acute pulmonary embolism (PE) is assumed to be secondary to elevated intracardiac chamber pressure. Since right ventricular (RV) hypertrophy does not develop in the acute setting, pressure overload correlates with chamber dilatation, causing myocardial injury. The aim of the present study was to investigate correlations between cardiac chamber volume, troponin and subsequent early mortality in patients with acute PE and refine risk stratification. Read More

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Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review.

Acta Ophthalmol 2021 Jul 11. Epub 2021 Jul 11.

Department of Ophthalmology, Tan Tock Seng Hospital, National Healthcare Group Eye Institute, Singapore, Singapore.

Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. Read More

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Altered Blood Flow in the Ophthalmic and Internal Carotid Arteries in Patients with Age-Related Macular Degeneration Measured Using Noncontrast MR Angiography at 7T.

AJNR Am J Neuroradiol 2021 Jul 1. Epub 2021 Jul 1.

Athinoula A. Martinos Center for Biomedical Imaging (M.L.H., Y.I.C., N. O., J.R.P.), Massachusetts General Hospital, Charlestown, Massachusetts

Background And Purpose: Age-related macular degeneration is associated with reduced perfusion of the eye; however, the role of altered blood flow in the upstream ophthalmic or internal carotid arteries is unclear. We used ultra-high-field MR imaging to investigate whether the diameter of and blood flow in the ophthalmic artery and/or the ICA are altered in age-related macular degeneration and whether any blood flow changes are associated with disease progression.

Materials And Methods: Twenty-four patients with age-related macular degeneration and 13 similarly-aged healthy controls participated. Read More

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Longitudinal Study of Retinal Structure, Vascular, and Neuronal Function in Patients With Relapsing-Remitting Multiple Sclerosis: 1-Year Follow-Up.

Transl Vis Sci Technol 2021 05;10(6)

Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA.

Objective: The purpose of this study was to quantify retinal structural, vascular, and functional changes in patients with relapsing-remitting multiple sclerosis (RRMS) over 1 year.

Methods: Eighty-eight eyes of 44 patients with RRMS underwent assessments of low contrast letter acuity (LCLA), retinal ganglion cell function detected by the steady-state pattern electroretinogram (PERG), axonal microstructural integrity measured as birefringence, intraretinal layer thicknesses by ultra-high-resolution optical coherence tomography (OCT), volumetric vessel density (VVD) by OCT angiography, and retinal tissue perfusion (RTP) by the Retinal Function Imager (RFI). All measurements were performed at baseline and 1-year follow-up. Read More

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Spatiotemporal registration and fusion of transthoracic echocardiography and volumetric coronary artery tree.

Int J Comput Assist Radiol Surg 2021 Jun 8. Epub 2021 Jun 8.

Cardiovascular Research Center, Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Purpose: Cardiac multimodal image fusion can offer an image with various types of information in a single image. Many coronary stenosis, which are anatomically clear, are not functionally significant. The treatment of such kind of stenosis can cause irreversible effects on the patient. Read More

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Renal Volumetry-based Prediction of the Presence of Accessory Renal Artery: Computed Tomographic Angiography-based Study with Clinical Implications on Renal Doppler.

J Med Ultrasound 2021 Jan-Mar;29(1):22-25. Epub 2020 Aug 24.

Department of Radiodiagnosis, Indraprastha Apollo Hospital, New Delhi, India.

Background: The objective was to validate the hypothesis and evaluate whether the presence or absence of accessory renal artery can be predicted on the basis of volumetric parameters of kidney and diameter of the main renal artery (mRA).

Methods: This retrospective analysis was performed in a total of 60 kidneys in 30 patients, who had computed tomographic (CT) angiography. The kidneys were segregated into control and study groups depending on the absence or presence of accessory renal artery. Read More

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Measuring Cardiac Output in a Swine Model.

J Vis Exp 2021 May 11(171). Epub 2021 May 11.

R Adams Cowley Shock Trauma Center, University of Maryland Medical System.

Swine are frequently used in medical research given their similar cardiac physiology to that of humans. Measuring cardiac parameters such as stroke volume and cardiac output are essential in this type of research. Contrast ventriculography, thermodilution, and pressure-volume loop (PV-loop) catheters can be used to accurately obtain cardiac performance data depending on which resources and expertise are available. Read More

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Comparing methods of detecting and segmenting unruptured intracranial aneurysms on TOF-MRAS: The ADAM challenge.

Neuroimage 2021 Sep 27;238:118216. Epub 2021 May 27.

Department of Informatics, Technische Universität München, Munich, Germany.

Accurate detection and quantification of unruptured intracranial aneurysms (UIAs) is important for rupture risk assessment and to allow an informed treatment decision to be made. Currently, 2D manual measures used to assess UIAs on Time-of-Flight magnetic resonance angiographies (TOF-MRAs) lack 3D information and there is substantial inter-observer variability for both aneurysm detection and assessment of aneurysm size and growth. 3D measures could be helpful to improve aneurysm detection and quantification but are time-consuming and would therefore benefit from a reliable automatic UIA detection and segmentation method. Read More

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September 2021

Development of an Endovascular Model of Pelvic Hemorrhage Using Volumetric Computed Tomography Validation.

J Endovasc Ther 2021 08 21;28(4):614-622. Epub 2021 May 21.

R. Adams Cowley Shock Trauma Center, University of Maryland Medical System, Baltimore, MD, USA.

Purpose: Uncontrolled pelvic hemorrhage from trauma is associated with mortality rates above 30%. The ability of an intervention to reduce blood loss from pelvic trauma is paramount to its success. The objective of this study was to determine if computed tomography volumetric analysis could be used to quantify blood loss in a porcine endovascular pelvic hemorrhage model. Read More

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Multi-MHz MEMS-VCSEL swept-source optical coherence tomography for endoscopic structural and angiographic imaging with miniaturized brushless motor probes.

Biomed Opt Express 2021 Apr 26;12(4):2384-2403. Epub 2021 Mar 26.

Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Swept source optical coherence tomography (SS-OCT) enables volumetric imaging of subsurface structure. However, applications requiring wide fields of view (FOV), rapid imaging, and higher resolutions have been challenging because multi-MHz axial scan (A-scan) rates are needed. We describe a microelectromechanical systems vertical cavity surface-emitting laser (MEMS-VCSEL) SS-OCT technology for A-scan rates of 2. Read More

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High-resolution, depth-resolved vascular leakage measurements using contrast-enhanced, correlation-gated optical coherence tomography in mice.

Biomed Opt Express 2021 Apr 2;12(4):1774-1791. Epub 2021 Mar 2.

Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.

Vascular leakage plays a key role in vision-threatening retinal diseases such as diabetic retinopathy and age-related macular degeneration. Fluorescence angiography is the current gold standard for identification of leaky vasculature however it lacks depth resolution, providing only 2D images that complicate precise identification and localization of pathological vessels. Optical coherence tomography (OCT) has been widely adopted for clinical ophthalmology due to its high, micron-scale resolution and rapid volumetric scanning capabilities. Read More

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Comparison of Central Macular Fluid Volume With Central Subfield Thickness in Patients With Diabetic Macular Edema Using Optical Coherence Tomography Angiography.

JAMA Ophthalmol 2021 Jul;139(7):734-741

Casey Eye Institute, Oregon Health & Science University, Portland.

Importance: Diabetic macular edema (DME) is the predominant cause of visual impairment in patients with type 1 or 2 diabetes. Automated fluid volume measurements using optical coherence tomography (OCT) may improve the diagnostic accuracy of DME screening.

Objective: To assess the diagnostic accuracy of an automated central macular fluid volume (CMFV) quantification using OCT for DME. Read More

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Vessel segmentation from volumetric images: a multi-scale double-pathway network with class-balanced loss at the voxel level.

Med Phys 2021 Jul 31;48(7):3804-3814. Epub 2021 May 31.

Xi'an Key Lab of Radiomics and Intelligent Perception, School of Information Sciences and Technology, Northwest University, Xi'an, Shaanxi, 710069, China.

Purpose: Vessel segmentation from volumetric medical images is becoming an essential pre-step in aiding the diagnosis, guiding the therapy, and patient management for vascular-related diseases. Deep learning-based methods have drawn many attentions, but most of them did not fully utilize the multi-scale spatial information of vessels. To address this shortcoming, we propose a multi-scale network similar to the well-known multi-scale DeepMedic. Read More

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Comparison of diametric and volumetric changes in Stanford type B aortic dissection patients in assessing aortic remodeling post-stent graft treatment.

Quant Imaging Med Surg 2021 May;11(5):1723-1736

Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.

Background: The study aims to analyze the correlation between the maximal diameter (both axial and orthogonal) and volume changes in the true (TL) and false lumens (FL) after stent-grafting for Stanford type B aortic dissection.

Method: Computed tomography angiography was performed on 13 type B aortic dissection patients before and after procedure, and at 6 and 12 months follow-up. The lumens were divided into three regions: the stented area (Region 1), distal to the stent graft to the celiac artery (Region 2), and between the celiac artery and the iliac bifurcation (Region 3). Read More

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Total flow intensity, active flow intensity and volume related flow intensity as new quantitative metrics in optical coherence tomography angiography.

Sci Rep 2021 Apr 27;11(1):9094. Epub 2021 Apr 27.

Department of Ophthalmology, IRCCS Ospedale San Raffaele, University Vita-Salute, via Olgettina 60, 20132, Milan, Italy.

Optical coherence tomography (OCT) angiography (OCTA) is a non-invasive tool for the in-vivo study of the intraretinal vascular network. It is based on the analysis of motion particles within the retina to reconstruct the paths followed by the erythrocytes, i.e. Read More

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A morphovolumetric analysis of aneurysm sac evolution after elective endovascular abdominal aortic repair.

J Vasc Surg 2021 Apr 15. Epub 2021 Apr 15.

Department of Medicine and Surgery, Vascular Surgery, University of Insubria School of Medicine, ASST Settelaghi Universitary Teaching Hospital, Varese, Italy. Electronic address:

Objective: Abdominal aortic aneurysm (AAA) sac shrinkage after endovascular aortic repair (EVAR) has been regarded as positive marker of EVAR success durability. The purpose of this study was to describe the morphovolumetric changes of the AAA sac during follow-up after elective EVAR and to analyze sac shrinkage-related variables.

Methods: This is a single-center, retrospective, observational cohort study from a tertiary referral university hospital. Read More

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Individualized brain development and cognitive outcome in infants with congenital heart disease.

Brain Commun 2021 23;3(2):fcab046. Epub 2021 Mar 23.

Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, UK.

Infants with congenital heart disease are at risk of neurodevelopmental impairments, the origins of which are currently unclear. This study aimed to characterize the relationship between neonatal brain development, cerebral oxygen delivery and neurodevelopmental outcome in infants with congenital heart disease. A cohort of infants with serious or critical congenital heart disease ( = 66;  = 62 born ≥37 weeks) underwent brain MRI before surgery on a 3T scanner situated on the neonatal unit. Read More

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Detection of severe pulmonary hypertension based on computed tomography pulmonary angiography.

Int J Cardiovasc Imaging 2021 Aug 7;37(8):2577-2588. Epub 2021 Apr 7.

Department of Radiology, Tel Aviv Medical Center, Tel Aviv, Affiliated to the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.

Pulmonary hypertension (PH) is often diagnosed late in the disease course. As many patients may undergo computed tomography pulmonary angiography (CTPA) for exclusion of pulmonary embolism (PE), we aimed to create a model that can detect the existence of PH and grade its severity. Consecutive patients who underwent CTPA which was negative for PE, and echocardiography study within 24 h, were included. Read More

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Evolving Diagnostic and Therapeutic Options for Visceral Artery Aneurysms.

Ann Vasc Surg 2021 Apr 3. Epub 2021 Apr 3.

Department of Cardiothoracic Surgery, Liverpool Heart and Chest Hospital, Liverpool, UK. Electronic address:

Background: Visceral artery aneurysms (VAAs) are associated with a very high mortality rate when ruptured and may present as a surgical emergency. Due to their rarity and varying pathophysiology, literature concerning the optimal management of VAAs is limited. This review evaluates the evolving management options for VAAs with a focus on open and endovascular repair. Read More

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LightSpeed: a compact, high-speed optical-link-based 3D optoacoustic imager.

IEEE Trans Med Imaging 2021 Apr 2;PP. Epub 2021 Apr 2.

Wide-scale adoption of optoacoustic imaging in biology and medicine critically depends on availability of affordable scanners combining ease of operation with optimal imaging performance. Here we introduce LightSpeed: a low-cost real-time volumetric handheld optoacoustic imager based on a new compact software-defined ultrasound digital acquisition platform and a pulsed laser diode. It supports the simultaneous signal acquisition from up to 192 ultrasound channels and provides a higbandwidth direct optical link (2x 100G Ethernet) to the host-PC for ultra-high frame rate image acquisitions. Read More

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A perfusion phantom for ASL MRI based on impinging jets.

Magn Reson Med 2021 08 27;86(2):1145-1158. Epub 2021 Mar 27.

Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.

Purpose: We present a novel perfusion phantom for validation of arterial spin labeled (ASL) perfusion MRI methods and protocols.

Methods: Impinging jets, driven by a peristaltic pump, were used to achieve perfusion-like mixing of magnetically labeled inflowing fluid within a perfusion compartment. The phantom was validated by varying pump rates and obtaining ASL-MRI data at multiple postlabeling delays using a pseudo-continuous ASL sequence with a 3D stack-of-spirals readout. Read More

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Motion-compensated 3D turbo spin-echo for more robust MR intracranial vessel wall imaging.

Magn Reson Med 2021 08 25;86(2):637-647. Epub 2021 Mar 25.

Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.

Purpose: (1) To investigate the effect of internal localized movement on 3DMR intracranial vessel wall imaging and (2) to develop a novel motion-compensation approach combining volumetric navigator (vNav) and self-gating (SG) to simultaneously compensate for bulk and localized movements.

Methods: A 3D variable-flip-angle turbo spin-echo (ie, SPACE) sequence was modified to incorporate vNav and SG modules. The SG signals from the center k-space line are acquired at the beginning of each TR to detect localized motion-affected TRs. Read More

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Effects of local coronary blood flow dynamics on the predictions of a model of in-stent restenosis.

J Biomech 2021 05 6;120:110361. Epub 2021 Mar 6.

University of Amsterdam, The Netherlands.

Computational models are increasingly used to study cardiovascular disease. However, models of coronary vessel remodelling usually make some strong assumptions about the effects of a local narrowing on the flow through the narrowed vessel. Here, we test the effects of local flow dynamics on the predictions of an in-stent restenosis (ISR) model. Read More

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Assessing volumetric changes in abdominal aortic aneurysms following endovascular repair.

Cardiovasc J Afr 2021 Mar 16;32:1-6. Epub 2021 Mar 16.

Department of Cardiovascular Surgery, Meram Faculty of Medicine, Necmettin Erbakan University, Konya, Turkey.

Objective: Volumetric changes in the aneurysm sac were evaluated following endovascular aortic repair (EVAR) in intact abdominal aortic aneurysm (AAA) patients who underwent EVAR.

Methods: Fifty-two patients, who underwent EVAR from 2015 to 2019, were analysed retrospectively. A total of 158 computed tomography angiography scans was examined by performing reconsctructive volumetric calculations. Read More

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Effect of A-scan rate and interscan interval on optical coherence angiography.

Biomed Opt Express 2021 Feb 6;12(2):722-736. Epub 2021 Jan 6.

Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.

Optical coherence tomography angiography (OCTA) can provide rapid, volumetric, and noninvasive imaging of tissue microvasculature without the requirement of exogenous contrast agents. To investigate how A-scan rate and interscan time affected the contrast and dynamic range of OCTA, we developed a 1.06-µm swept-source OCT system enabling 100-kHz or 200-kHz OCT using two light sources. Read More

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February 2021

Diagnostic accuracy of three-dimensional-rotational angiography and heavily T2-weighted volumetric magnetic resonance fusion imaging for the diagnosis of spinal arteriovenous shunts.

J Neurointerv Surg 2021 Mar 4. Epub 2021 Mar 4.

Neuroendovascular Therapy, St. Luke's International Hospital, Chuo-ku, Tokyo, Japan.

Background: Spinal arteriovenous shunts (SAVSs) are rare entities occurring in various areas, from the craniocervical junction to the sacral level. Recently, better understanding of SAVS angioarchitecture and elucidation of its pathogenesis have become possible with the advancement of imaging techniques. However, the utility of fusing different image modalities for SAVS diagnostics has not been determined. Read More

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[Impact of 3D printing in surgical planning of congenital heart disease].

Arch Cardiol Mex 2021 ;91(1):1-6

Departamento de Cardiología Nuclear, Instituto Nacional de Cardiología Ignacio Chávez. Ciudad de México, México.

Introducción: Los defectos cardíacos congénitos constituyen el 30% de todas las anomalías congénitas. La prevalencia es de 8/1,000 recién nacidos vivos, sin predominio de género. Para una planificación quirúrgica óptima es esencial una evaluación precisa de la anatomía en los defectos cardíacos congénitos. Read More

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January 2021

Optimizing 3D retinal vasculature imaging in diabetic retinopathy using registration and averaging of OCT-A.

Biomed Opt Express 2021 Jan 22;12(1):553-570. Epub 2020 Dec 22.

School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.

High resolution visualization of optical coherence tomography (OCT) and OCT angiography (OCT-A) data is required to fully take advantage of the imaging modality's three-dimensional nature. However, artifacts induced by patient motion often degrade OCT-A data quality. This is especially true for patients with deteriorated focal vision, such as those with diabetic retinopathy (DR). Read More

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January 2021