48 Contrast-Enhanced MRA: Peripheral Circulation
Figure 48.1A illustrates 3D contrast-enhanced MR angiography (CE-MRA) of the lower extremities in a patient with no significant stenoses or occlusions. The adjacent 3D CE-MRA examination of the femoropopliteal distribution (Fig. 48.1B) reveals, in a different patient, bilateral superficial femoral artery occlusion with development of profunda femoral artery collaterals. Figure 48.1C and Fig. 48.1D are multiphase CE-MRA images of the tibioperoneal distribution obtained during early arterial enhancement and (with a slight time delay) after substantial venous filling. In the latter image, the large vascular malformation in the left gastrocnemius is more completely visualized because of opacification of the venous component.
Peripheral MRA may be performed in three ways: time-of-flight (TOF) (see Cases 42 and 43), phase-contrast (see Case 45