Dual-phase 3D MDCT angiography for evaluation of the liver before hepatic resection

OBJECTIVE. We sought to evaluate the accuracy of dual-phase MDCT angiography for assessing the liver before hepatic resection and to compare 2D and 3D images for quality and arterial branch visualization. MATERIALS AND METHODS. Sixty-three patients with colorectal metastases (n 30), hepatocellular carcinomas (n = 13), giant hemangiomas (n = 5), and other lesions (it = 15) underwent dual-phase MDCT using either a LightSpeed QX/i 4-MDCT (n = 31) or LightSpeed QX/i Ultra 8-MDCT (n = 32) scanner. Contrast material (150 mL of Isovue 370 [iopamidol]) was injected at a rate of 5 mL/sec. The arterial phase images were rendered on a workstation to obtain 3D MDCT angiograms that were assessed by two reviewers who were blinded to the surgical findings. Arterial anatomy was categorized according to the Michels classification. The reviewers assessed the 2D and 3D images for quality, arterial branch visualization, and differences between the 4- and 8-MDCT images. In the 43 patients who underwent resection, imaging findings were correlated with intraoperative findings. RESULTS. The anatomy of hepatic arteries in the 63 patients was classified as follows: Michels type I, 51 patients (80.9%); type III, four patients (6.3%); type V, five patients (7.9%); and types VII, VIII, and IX, one patient (1.6%) each. In 40 (93%) of 43 patients, the surgical findings concurred with MDCT findings. Three discrepancies were due to failure to identify small accessory left hepatic arteries. Branch visualization and image quality of the 2D images were superior to those of the 3D images. No significant difference was found between the 4- and 8-MDCT images in branch visualization and image quality. CONCLUSION. Three-dimensional MDCT angiography is accurate for classification of hepatic arterial anatomy before hepatic resection. Although 2D data sets show small arteries to better advantage than 3D MDCT angiograms, the 3D MDCT angiograms provide a useful overview of hepatic anatomy.