[Digital radiography--clinical application of digital subtraction angiography]

Injection technique, advantages, disadvantages and main indications of DSA were briefly described and discussed. Advantages of DSA: (1) relatively noninvasive, (2) can be performed on an outpatient basis, therefore "cost-effective", (3) real time observation possible. Disadvantages of DSA: (1) limited spatial resolution, (2) artefacts, (3) small visual field. Main indications of DSA: (1) diagnosis and follow up study of vascular diseases, (2) evaluation of patency of by-pass graft, (3) functional assessment (of cardiac output and blood flow etc.). Aortic aneurysms, occlusive changes of the carotid or renal arteries are particularly well demonstrated by DSA. Because of three drawbacks mentioned above, DSA is not a good technique for the diagnosis of neoplasms. Although it is possible to visualize hypervascular tumors by DSA, informations obtained by DSA in cases of neoplasms are limited.