Dependence of venous enhancement on the field of view in 3D contrast-enhanced MRA using the elliptical centric view order.

The dependence of venous suppression on the acquisition field of view (FOV) in elliptical centric 3D contrast-enhanced magnetic resonance angiography (CE-MRA) is studied theoretically and experimentally. It is hypothesized that a reduced FOV in an arterial phase acquisition results in improved venous suppression. An expression is derived linking the k-space representation of a vein to venous return time and acquisition parameters. For a y x z FOV reduction from 24 cm x 7.2 cm to 18 cm x 3.6 cm, equivalent voxel size, and venous return times ranging from 0-7 s, the mean improvement in venous suppression ranged from 7.0% for the 19-mm-diameter vein to 32.1% in the 6-mm-diameter vein, assuming a step function-shaped venous enhancement profile. Decreased venous enhancement with reduced FOV is also observed for scans with equivalent acquisition times, although the degree of suppression is dependent on the shape of the venous enhancement curve.