MR-ANGIOGRAPHY OF ABDOMINAL AND PERIPHERAL ARTERIES - TECHNIQUES AND CLINICAL-APPLICATIONS

This review article deals with MR angiography (MRA) of abdominal and p eripheral arteries. Pulsatile flow, respiratory motion and peristalsis impose difficulties in imaging the vascular structures in the abdomen and the lower extremities. Development of new techniques, such as seg mentation of the data acquisition, using specific acquisition windows in relation to a cardiac trigger, magnetization preparation of the tis sue and phase-encoding re-ordering or sorting, have reduced the artifa cts associated with abdominal and peripheral MRA. Clinical MR investig ations of the arteries branching from the abdominal aorta such as the renal and mesenteric arteries and arteries in the lower extremities ha ve revealed that severe stenoses or occlusions can be diagnosed accura tely while the grading of less severe stenosis is more difficult. The phase-contrast method has been used to quantify blood flow and study t he hemodynamics in abdominal and peripheral vessels. Quantitative flow information can be used to diagnose vascular disease and provides imp ortant physiological information. More prospective clinical studies, i n which recently developed MRA techniques are compared with convention al angiography, are necessary before conclusive decisions can be made as to whether MRA may replace these methods.