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Critical Reviews in Biomedical... 2005The discovery of X-rays over a century ago enabled noninvasive examination of the human body. Contrast agents that enhanced X-ray images were soon developed that... (Review)
Review
The discovery of X-rays over a century ago enabled noninvasive examination of the human body. Contrast agents that enhanced X-ray images were soon developed that advanced angiology by allowing exploration of the vascular tree. Starting as a diagnostic tool, angiography underwent technological transformations over the last century and became a basis for interventional therapy as well. Initially a static two-dimensional record of the vasculature on screen films, angiography has evolved to real-time two-dimensional display of the vasculature on television monitors, three-dimensional reconstruction from computerized tomographic (CT) scans, and, more recently, three-dimensional cone-beam reconstruction. Cinematographic angiography is referred to as dynamic angiography in current terminology, but it essentially provides no more than images of vascular structures and changes therein. Although dynamic angiography has facilitated advances in image-guided interventions, the evaluation of blood flow rate, or perfusion, and blood flow velocity using angiography remains elusive. Many lines of research have been pursued toward enabling such evaluations, but none have found their way into clinical practice. This article reviews angiographic flow assessment methods attempted over the past several decades and explores some new avenues that may facilitate the transfer of such methods into the clinical practice of diagnostic and interventional angiography and, eventually, contribute to better patient care.
Topics: Angiography; Blood Flow Velocity; Humans; Imaging, Three-Dimensional; Radiographic Image Interpretation, Computer-Assisted; Surgery, Computer-Assisted
PubMed: 15777157
DOI: 10.1615/critrevbiomedeng.v33.i1.10 -
Radiologic Technology 2001
Topics: Angiography; Humans; Radiology, Interventional
PubMed: 11394389
DOI: No ID Found -
Lancet (London, England) Jun 1992
Topics: Angiography; Humans; Thromboembolism
PubMed: 1351556
DOI: No ID Found -
Soins. Chirurgie (Paris, France : 1982) Apr 1996
Topics: Angiography; Humans; Peripheral Vascular Diseases; Postoperative Care
PubMed: 8717720
DOI: No ID Found -
Developments in Ophthalmology 2016Optical coherence tomography (OCT) angiography (OCT-A) is a transformative approach in imaging ocular vessels based on flow rather than simple reflectance intensity. It... (Review)
Review
Optical coherence tomography (OCT) angiography (OCT-A) is a transformative approach in imaging ocular vessels based on flow rather than simple reflectance intensity. It is therefore a functional extension of OCT that can be used to visualize microvasculature by detecting motion contrast from flowing blood. As OCT-A is a depth-resolved examination, it needs careful axial segmentation in order to preserve important data on perfused structures and to avoid the risk of generating superimposed images, which are typical of dye angiographies. An automated segmentation algorithm for both retinal and choroidal layers is provided by the majority of different OCT-A devices. In the case of accentuated macular retinal/choroidal disruptions causing potential segmentation errors, specific manual correction allows one to modify the shape and the localization of each layer. In the case of manual segmentation, the thickness of every C-scan may be modified in order to provide a constant thickness of tissue slices at different retinal or choroidal levels. OCT projection artifacts also occur from superficial retinal vessels, which can be seen in deeper retinal layers, or retinal and choroidal vessels, which can even be seen in the scleral tissue. These projection artifacts are almost always present and are visible in any layer that is located below the perfused vasculature.
Topics: Angiography; Animals; Artifacts; Choroid; Diagnostic Techniques, Ophthalmological; Fluorescein Angiography; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Regional Blood Flow; Retinal Vessels; Tomography, Optical Coherence
PubMed: 27023365
DOI: 10.1159/000442774 -
Clinical Cardiology Jan 1991Angiographic imaging suffers from many limitations which may distort the diagnostic information obtained from coronary arteriograms. Radiographic features limiting... (Review)
Review
Angiographic imaging suffers from many limitations which may distort the diagnostic information obtained from coronary arteriograms. Radiographic features limiting precise coronary stenosis measurement are caused by the x-ray source, the image intensifier, and the chemical properties of the cinefilm. Biologic variations are introduced by fluctuations in angiographic contrast concentration and flow- or contrast-dependent coronary dilation. Random errors are also introduced by the selection of the radiographic projection and frame to be analyzed and the digitization of cineangiograms. These limitations and their significance in distorting quantitative information obtained from coronary angiograms are discussed in this review.
Topics: Angiography; Cineangiography; Coronary Angiography; Coronary Artery Disease; Coronary Vessels; Humans
PubMed: 2019026
DOI: 10.1002/clc.4960140106 -
Health Devices Nov 1993Despite the emergence of several alternative angiographic imaging techniques (i.e., magnetic resonance imaging, computed tomography, and ultrasound angiography), x-ray...
Despite the emergence of several alternative angiographic imaging techniques (i.e., magnetic resonance imaging, computed tomography, and ultrasound angiography), x-ray angiography remains the predominant vascular imaging modality, generating over $4 billion in revenue a year in U.S. hospitals. In this issue, we provide a brief overview of the various angiographic imaging techniques, comparing them with x-ray angiography, and discuss the clinical aspects of x-ray vascular imaging, including catheterization and clinical applications. Clinical, cost, usage, and legal issues related to contrast media are discussed in "Contrast Media: Ionic versus Nonionic and Low-osmolality Agents." We also provide a technical overview and selection guidance for a basic x-ray angiography imaging system, including the gantry and table system, x-ray generator, x-ray tube, image intensifier, video camera and display monitors, image-recording devices, and digital acquisition and processing systems. This issue also contains our Evaluation of the GE Advantx L/C cardiac angiography system and the GE Advantx AFM general-purpose angiography system; the AFM can be used for peripheral, pulmonary, and cerebral vascular studied, among others, and can also be configured for cardiac angiography. Many features of the Advantx L/C system, including generator characteristics and ease of use, also apply to the Advantx AFM as configured for cardiac angiography. Our ratings are based on the systems' ability to provide the best possible image quality for diagnosis and therapy while minimizing patient and personnel exposure to radiation, as well as its ability to minimize operator effort and inconvenience. Both units are rated Acceptable. In the Guidance Section, "Radiation Safety and Protection," we discuss the importance of keeping patient and personnel exposures to radiation as low as reasonably possible, especially in procedures such as cardiac catheterization, angiographic imaging for special procedures, and interventional radiology, which produce among the highest radiation exposure of all x-ray imaging techniques. We also provide recommendations for minimizing personnel and patient exposures to radiation. For more information about x-ray angiography systems and similar devices, as well as for additional perspectives on which we based this study, see the following Health Devices Evaluations: "Mobile C-arm Units" (19[8], August 1990) and "Noninvasive Electronic Quality Control Devices for X-ray Generator Testing" (21[6-7], June-July 1992).(ABSTRACT TRUNCATED AT 400 WORDS)
Topics: Angiography; Catheterization; Equipment Design; Equipment Safety; Evaluation Studies as Topic; Heart Diseases; Humans; Radiation Protection; Technology Assessment, Biomedical
PubMed: 8119801
DOI: No ID Found -
The Medical Clinics of North America Nov 1986Digital subtraction angiography is a new imaging technique that uses a computer to subtract background distractions and to enhance contrast and density. The intravenous...
Digital subtraction angiography is a new imaging technique that uses a computer to subtract background distractions and to enhance contrast and density. The intravenous administration of contrast material permits safe outpatient screening for arterial disease. The exact role of intravenous digital subtraction angiography in cerebrovascular disease is still in evolution and remains the subject of debate. The value of intravenous digital subtraction angiography in screening for renovascular hypertension is less controversial, but selection of patients remains a subject for further study. Intra-arterial digital subtraction angiography has become a standard imaging technique that offers both the inherent safety produced by reduction of the volume of contrast material and the added safety afforded by reduction of both the size of the catheter and the time required to perform complex arterial interventional procedures. With the evolution of more sophisticated computed technology and radiographic equipment, the impact of both intravenous and arterial digital subtraction angiography will become even more dramatic.
Topics: Angiography; Computers; Contrast Media; Humans; Vascular Diseases
PubMed: 3784691
DOI: 10.1016/s0025-7125(16)30896-3 -
Surgical Technology International 2004Recent trends in computed tomography (CT) scanner technology has opened new frontiers in the field of non-invasive coronary angiography. Given the relatively important... (Comparative Study)
Comparative Study Review
Recent trends in computed tomography (CT) scanner technology has opened new frontiers in the field of non-invasive coronary angiography. Given the relatively important number of negative invasive angiographies performed each year, eliminating the risks inherent to this procedure by non-invasive methods greatly contribute to diminishing the risk. After injection of contrast, the procedure is performed under short apnea and triggered by electrocardiographic (ECG) recording that provides a multitude of possible image reconstructions; ie, volume rendering, virtual angioscopy, and three-dimensional (3D) reconstruction of the heart and coronary vessels. In 100 patients, adequate visualisation of the coronary arteries was achieved in 98%, with the advantage of visualizing the coronary wall as well as the lumen. The main reasons for failure were arrhythmia and excessive motion. Besides evaluating coronary artery atherosclerosis, computed tomography angiography (CTA) allowed the diagnosis of coronary aneurysm and exact localization of postoperative false aneurysm. The main disadvantages of the technique are the absence of dynamic films and exposure to radiation. The increased accuracy and sensitivity of noninvasive coronary angiography make it an excellent diagnostic tool and a probable replacement to invasive procedures. It should reduce the morbidity and mortality as well as the cost of conventional coronary arteriography. Furthermore, it has the added benefit of offering spacial resolution of the examined vessels.
Topics: Coronary Angiography; Coronary Disease; Female; Forecasting; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Male; Sensitivity and Specificity; Tomography, Spiral Computed
PubMed: 15744692
DOI: No ID Found -
Lancet (London, England) Sep 1984
Topics: Angiography; Computers; Coronary Angiography; Humans; Subtraction Technique
PubMed: 6148503
DOI: 10.1016/s0140-6736(84)92660-6