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Progress in Retinal and Eye Research Sep 2017OCT has revolutionized the practice of ophthalmology over the past 10-20 years. Advances in OCT technology have allowed for the creation of novel OCT-based methods.... (Review)
Review
OCT has revolutionized the practice of ophthalmology over the past 10-20 years. Advances in OCT technology have allowed for the creation of novel OCT-based methods. OCT-Angiography (OCTA) is one such method that has rapidly gained clinical acceptance since it was approved by the FDA in late 2016. OCTA images are based on the variable backscattering of light from the vascular and neurosensory tissue in the retina. Since the intensity and phase of backscattered light from retinal tissue varies based on the intrinsic movement of the tissue (e.g. red blood cells are moving, but neurosensory tissue is static), OCTA images are essentially motion-contrast images. This motion-contrast imaging provides reliable, high resolution, and non-invasive images of the retinal vasculature in an efficient manner. In many cases, these images are approaching histology level resolution. This unprecedented resolution coupled with the simple, fast and non-invasive imaging platform have allowed a host of basic and clinical research applications. OCTA demonstrates many important clinical findings including areas of macular telangiectasia, impaired perfusion, microaneurysms, capillary remodeling, some types of intraretinal fluid, and neovascularization among many others. More importantly, OCTA provides depth-resolved information that has never before been available. Correspondingly, OCTA has been used to evaluate a spectrum of retinal vascular diseases including diabetic retinopathy (DR), retinal venous occlusion (RVO), uveitis, retinal arterial occlusion, and age-related macular degeneration among others. In this review, we will discuss the methods used to create OCTA images, the practical applications of OCTA in light of invasive dye-imaging studies (e.g. fluorescein angiography) and review clinical studies demonstrating the utility of OCTA for research and clinical practice.
Topics: Angiography; Humans; Retina; Retinal Diseases; Retinal Vessels; Tomography, Optical Coherence
PubMed: 28760677
DOI: 10.1016/j.preteyeres.2017.07.002 -
Turk Kardiyoloji Dernegi Arsivi : Turk... Jun 2021
Topics: Arterial Occlusive Diseases; Coronary Angiography; Humans; Radial Artery; Ultrasonography, Interventional
PubMed: 34106057
DOI: 10.5543/tkda.2021.21114 -
JACC. Cardiovascular Imaging May 2019
Topics: Coronary Angiography; Fractional Flow Reserve, Myocardial
PubMed: 29550309
DOI: 10.1016/j.jcmg.2018.02.013 -
Journal of Vascular Surgery Aug 2017Unfamiliarity of endovascular surgeons with carbon dioxide (CO) angiography is one of the main reasons for its limited use. This review is intended to familiarize the... (Review)
Review
OBJECTIVE
Unfamiliarity of endovascular surgeons with carbon dioxide (CO) angiography is one of the main reasons for its limited use. This review is intended to familiarize the reader with the principles and applications of that modality.
METHODS
We conducted a comprehensive review of contemporary literature related to CO angiography and its use in the field of vascular and endovascular surgery, including technical details and diagnostic and interventional applications.
RESULTS
Cardinal physicochemical characteristics of CO include buoyancy, ultralow viscosity, and nonmixing with blood. Because of the risk of neurotoxicity, intra-arterial CO angiography should only be performed below the diaphragm. Venous CO angiography can be performed anywhere in the torso and extremities. Ultralow viscosity enables intraprocedural imaging during vascular interventions without the need to exchange for an angiographic catheter. Benefits, advantages, and emerging applications of CO angiography are listed. Potential complications and their avoidance and troubleshooting are discussed.
CONCLUSIONS
CO holds promise as an effective and versatile angiographic contrast agent. It is also a valuable modality for the guidance of endovascular interventions. Current availability of easy to use, safe, and portable CO delivery systems will likely expand the use of that modality even beyond the traditional indications of renal insufficiency and iodinated contrast allergy.
Topics: Angiography; Carbon Dioxide; Contrast Media; Endovascular Procedures; Equipment Design; Humans; Predictive Value of Tests; Radiography, Interventional; Reproducibility of Results; Risk Factors; Treatment Outcome; Vascular Diseases
PubMed: 28735955
DOI: 10.1016/j.jvs.2017.03.446 -
Scientific Reports Jan 2024World Health Organization stated that "Cardiovascular diseases (CVDs) are the leading cause of death globally. Angiography is an important method in diagnostic of CVD....
World Health Organization stated that "Cardiovascular diseases (CVDs) are the leading cause of death globally. Angiography is an important method in diagnostic of CVD. Standard-of-Care methods of angiography, such as X-Ray or CT- or MRI- angiography methods, being accurate and widely adopted in clinical practice, are bulky, expensive and energy in-efficient. X-ray and CT- angiography methods are also potentially hazardous as techniques require the use of ionizing contrast agents. Electromagnetic tomography (EMT) is an emerging medical imaging modality. EMT is applicable for safe functional imaging but suffers from a limited spatial resolution because of relatively large wavelength of electromagnetic radiation as compared to sizes of biological targets of particular interest, such as, for example blood vessels. Novel approach and method, presented in the study is capable to overcome such limitations and provide a mean for a dynamic, on-line EMT angiography. New method of EMT angiography was presented in application to cerebral angiography. Achieved imaging results clearly demonstrate applicability of the method for detecting small cerebral vessels of the diameter as small as 1.3 mm and to distinguish vessels with different dimensions. The technical challenges in the development of angiography capable EMT systems are assessed and discussed.
Topics: Humans; Cerebral Angiography; Tomography, X-Ray Computed; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Cardiovascular Diseases; Electromagnetic Phenomena
PubMed: 38245538
DOI: 10.1038/s41598-024-51632-4 -
Journal of Reconstructive Microsurgery Mar 2022The benefits of preoperative perforator imaging for microsurgical reconstruction have been well established in the literature. (Review)
Review
BACKGROUND
The benefits of preoperative perforator imaging for microsurgical reconstruction have been well established in the literature.
METHODS
An extensive literature review was performed to determine the most commonly used modalities, and their applicability, advantages and disadvantages.
RESULTS
The review demonstrated varioius findings including decreases in operative time and cost with the use of CT angiography to identification of perforators for inclusion in flap design with hand-held Doppler ultrasound. Modalities like MR angiography offer alternatives for patients with contrast allergies or renal dysfunction while maintaining a high level of clarity and fidelity. Although the use of conventional angiography has decreased due to the availability of less invasive alternatives, it continues to serve a role in the preoperative evaluation of patients for lower extremity reconstruction. Duplex ultrasonography has been of great interest recently as an inexpensive, risk free, and extraordinarily accurate diagnostic tool. Emerging technologies such as indocyanine green fluorescence angiography and dynamic infrared thermography provide real-time information about tissue vascularity and perfusion without requiring radiation exposure.
CONCLUSION
This article presents an in-depth review of the various imaging modalities available to reconstructive surgeons and includes hand held Doppler ultrasound, CT angiography, MR angiography, conventional angiography, duplex ultrasonography, Indocyanine Green Fluorescence Angiography and Dynamic Infrared Thermography.
Topics: Angiography; Computed Tomography Angiography; Humans; Perforator Flap; Preoperative Care; Plastic Surgery Procedures; Surgical Flaps
PubMed: 34688218
DOI: 10.1055/s-0041-1736316 -
Experimental Biology and Medicine... Oct 2021Optical coherence tomography angiography (OCTA) offers a noninvasive label-free solution for imaging retinal vasculatures at the capillary level resolution. In... (Review)
Review
Optical coherence tomography angiography (OCTA) offers a noninvasive label-free solution for imaging retinal vasculatures at the capillary level resolution. In principle, improved resolution implies a better chance to reveal subtle microvascular distortions associated with eye diseases that are asymptomatic in early stages. However, massive screening requires experienced clinicians to manually examine retinal images, which may result in human error and hinder objective screening. Recently, quantitative OCTA features have been developed to standardize and document retinal vascular changes. The feasibility of using quantitative OCTA features for machine learning classification of different retinopathies has been demonstrated. Deep learning-based applications have also been explored for automatic OCTA image analysis and disease classification. In this article, we summarize recent developments of quantitative OCTA features, machine learning image analysis, and classification.
Topics: Angiography; Capillaries; Deep Learning; Humans; Image Processing, Computer-Assisted; Retinal Diseases; Retinal Vessels; Tomography, Optical Coherence
PubMed: 34279136
DOI: 10.1177/15353702211026581 -
International Angiology : a Journal of... Aug 2023This study aimed to investigate whether intravascular ultrasound (IVUS) combined with angiography during percutaneous transluminal angioplasty impacts treatment...
BACKGROUND
This study aimed to investigate whether intravascular ultrasound (IVUS) combined with angiography during percutaneous transluminal angioplasty impacts treatment strategies and the 12-month patency of the femoropopliteal artery, compared to angiography alone.
METHODS
This retrospective, single-center study enrolled 137 patients who underwent a femoropopliteal endovascular intervention between February 2020 and May 2021. Among these interventions, 43 were guided by IVUS combined with angiography and the remaining 94 were guided by angiography only. Treatment strategies and 12-month patency were analyzed in both groups. Multivariable analysis was performed to clarify the predictors of restenosis within 12 months.
RESULTS
Primary patency at 12 months was significantly higher in the IVUS group than in the angiography group (56.4% vs. 76.7%, P=0.047). The reference diameter on IVUS images was greater than that on angiography images. Therefore, the IVUS group presented a higher balloon-to-vessel ratio [1.0 (0.97, 1.01) vs. 1.06 (1.0.1.25)]. More adjunctive stents were required in the angiography group. However, more dissections were performed in the IVUS group, with no difference in flow-limiting dissections between groups. Target disease length (odds ratio 1.02, P=0.021) and balloon-to-vessel ratio (odds ratio 0.01, P=0.021) were independent predictors of restenosis.
CONCLUSIONS
Compared with angiography guidance alone, IVUS guidance for femoropopliteal artery-related treatment can significantly increase primary patency. This finding may be explained by the selection of larger balloons in IVUS and the resulting sufficient plaque compression and elastic membrane stretch. Moreover, IVUS was shown to detect more non-flow-limiting dissections than angiography.
Topics: Humans; Angiography; Angioplasty; Femoral Artery; Retrospective Studies; Stents; Treatment Outcome; Ultrasonography, Interventional; Vascular Patency
PubMed: 37347157
DOI: 10.23736/S0392-9590.23.05064-2 -
Diagnostic and Interventional Imaging Sep 2022Diagnostic radiologists play an important role in the evaluation of patients presenting with signs and symptoms of lower extremity peripheral vascular disease, including... (Review)
Review
Diagnostic radiologists play an important role in the evaluation of patients presenting with signs and symptoms of lower extremity peripheral vascular disease, including critical limb ischemia in both acute and chronic settings, and intermittent claudication. The complications associated with tissue and/or limb loss related to acute limb ischemia and critical limb ischemia of the lower extremity make rapid diagnosis and early intervention critical in the management of these patients. Computed tomography angiography (CTA) is an effective, widely available, easily reproducible, non-invasive imaging modality that offers a rapid and accurate means to diagnose and grade the extent of vascular disease. However, CTA run-off reports are usually dictated in free text form, and referring and treating physicians may be unsure whether an anatomic structure has been evaluated if it has not been specifically mentioned in the report. In this article, the vascular anatomy and anatomic variants of the lower extremity, the most common lower extremity vascular pathologies are reviewed and clinically important CTA imaging findings are outlined. This provides a framework for radiologists to accurately evaluate lower extremity vascular pathologies and convey clinically relevant imaging findings for management by vascular surgeons or interventional radiologists.
Topics: Angiography; Computed Tomography Angiography; Humans; Ischemia; Lower Extremity; Peripheral Vascular Diseases
PubMed: 35843841
DOI: 10.1016/j.diii.2022.06.010 -
Asia-Pacific Journal of Ophthalmology... 2019
Topics: Angiography; Eye Diseases; Humans; Image Processing, Computer-Assisted; Tomography, Optical Coherence
PubMed: 31037875
DOI: 10.22608/APO.201984