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Evaluation of reconstructed hepatic veins with breath-hold 2D time-of-flight MR venography.

PURPOSE
The purpose of this study was to assess the ability of magnetic resonance (MR) venography to evaluate the patency of reconstructed hepatic veins after surgery.


PATIENTS AND METHODS
Five normal volunteers with normal hepatic veins and eight patients who underwent reconstruction of the hepatic veins after resection of hepatic tumors were included. All subjects underwent breath-hold two-dimensional (2D) time-of-flight MR venography using a fast low angle shot (FLASH) technique with a 1.5 Tesla magnet. The initial imaging plane was coronal, and sagittal and/or transverse planes were added when necessary. Data were postprocessed with a maximum intensity projection (MIP) algorithm. In six patients, the MR findings were verified by iodinated hepatic venography.


RESULTS
The confidence level increased when patency was evaluated using a combination of MIP and source images or other imaging planes compared with the use of MIP images alone (3.0 to 3.6, p < 0.05). A signal drop near the orifice at the inferior vena cava was observed in three normal patients. The severity of stenosis was overestimated by MR venography in five patients. Obstruction was correctly suggested in one patient.


CONCLUSION
Although 2D time-of-flight MR venography overestimated stenosis of the hepatic vein at the site of connection, it might provide information on the patency of reconstructed hepatic veins especially when more than one orthogonal plane is used and both MIP and source images are evaluated.