Dynamic contrast-enhanced three-dimensional MR imaging of liver parenchyma: Source images and angiographic reconstructions to define hepatic arterial anatomy

PURPOSE: To assess the accuracy of an interpolated breath-hold T1-weighted three-dimensional (3D) gradient-echo (GRE) magnetic resonance (MR) imaging sequence with near-isotropic pixel size (≤2.3 mm) for evaluation of hepatic arterial anatomy variants during dynamic liver parenchymal imaging and to report patterns of hepatic arterial anatomy. MATERIALS AND METHODS: Liver MR imaging, including an interpolated breath-hold 3D GRE sequence with fat suppression (4.2/1.8 [repetition time msec/echo time msec], 12° flip angle), was performed in 207 consecutive patients before and after gadopentetate dimeglumine administration. Of the 207 patients, 202 (98%) had technically satisfactory studies clearly defining the hepatic arterial system. The first contrast material-enhanced GRE acquisition was timed for optimal arterial enhancement with a timing examination. In a retrospective review, hepatic arteries were evaluated on the basis of arterial phase images interpreted by two independent readers using transverse source images complemented by multiplanar reconstructions. Twenty-three patients also underwent digital subtraction angiography, which was a reference standard for comparison. RESULTS: Conventional hepatic arterial anatomy was demonstrated in 135 (67%) of 202 patients. In the 23 patients with angiographic correlation, no discrepancy was noted between MR imaging and digital subtraction angiographic findings. CONCLUSION: Hepatic arterial anatomy can be reliably demonstrated during liver parenchymal imaging with an optimally timed contrast-enhanced isotropic 3D GRE sequence.