Radiography of blood vessels made visible by injecting into them a radio-opaque substance. In the case of arteries this is known as arteriography; the corresponding term for veins being venography or phlebography. This procedure demonstrates whether there is any narrowing or ballooning of the lumen of the vessel, changes usually caused by disease or injury.... angiography
(CR) a system for replacing photographic film with a charged plate. Exposure to X-rays knocks charge off the plate. The resultant image can be read by a laser beam and stored digitally or printed out as required. This system is widely used in conjunction with *PACS systems.... computerized radiography
(CT) a form of X-ray examination in which the X-ray source and detector (CT scanner) rotate around the object to be scanned and the information obtained can be used to produce cross-sectional images (see cross-sectional imaging) by computer (a CT scan). A higher radiation dose is received by the patient than with some conventional X-ray techniques, but the diagnostic information obtained is far greater and should outweigh the increased risk. CT scanning can be used for all parts of the body. The data obtained can be used to construct three-dimensional images of structures of interest. See also multidetector computerized tomography; spiral CT scanning.... computerized tomography
an X-ray technique for examination of the coronary arteries, often taken to also include examination of the chambers of the heart. A catheter is introduced via the radial artery at the wrist or the femoral artery at the groin and manipulated into the heart under X-ray control. *Contrast medium is then injected to outline the ventricles and coronary arteries. Digital video images are recorded during contrast-medium injection. Coronary angiography is used to diagnose cardiac disease, specifically narrowing or blockage in the coronary arteries, and plan treatment by surgery or radiological interventional techniques (see coronary artery bypass graft; percutaneous coronary intervention). It has now largely been replaced by CT coronary angiography.... coronary angiography
(MDCT) a development of *spiral CT scanning that uses more than one array of detectors opposite the X-ray tube, so that more tissue can be included, with thinner cuts, in a single rotation of the machine. This is particularly important for three-dimensional reconstruction of tissues. It also allows volumetric scanning or *isotropic imaging, which are best achieved when the thickness of the slice is similar to the size resolution of the detectors in the other two planes. Modern CT scanners are now usually equipped with between 16 and 640 detector arrays. The technique is particularly valuable for imaging fast-moving structures, such as the heart.... multidetector computerized tomography
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