Timing of the hepatic arterial phase at Gd‐EOB‐DTPA‐enhanced hepatic dynamic MRI: Comparison of the test‐injection and the fixed‐time delay method

Purpose To compare the fixed‐time‐ and the test‐injection method with respect to the image quality of hypervascular hepatocellular carcinoma (HCC) and the adequacy of timing of the hepatic arterial phase (HAP) in Gd‐EOB‐DTPA (EOB) enhanced MRI. Materials and Methods We studied 63 patients with computed tomography (CT) ‐proven hypervascular HCC: 30 (group 1) were scanned HAP using the fixed‐time delay method (protocol 1); in the other 33 (group 2), we applied the test‐injection method (protocol 2). We compared the protocols with respect with tumor‐to‐liver contrast (TLC), contrast‐to‐noise‐ratio (CNR), and relative enhancement of the liver and tumor (RE L , RE T ) during HAP. Two radiologists compared the adequacy of HAP, image contrast, image noise, and overall image quality. Results Under protocol 2, TLC, CNR, and RE L and RE T of hypervascular HCC were significantly higher ( P < 0.01). The proportion of optimal HAP was significantly higher for protocol 2 than protocol 1 ( P < 0.01). The visual score of the image contrast and the overall image quality were significantly higher in group 2 than group 1 ( P = 0.02 and P = 0.01, respectively). Conclusion At EOB‐enhanced hepatic dynamic MRI, the test‐injection method yielded better image quality of hypervascular HCC and improved adequacy of timing of HAP. J. Magn. Reson. Imaging 2012;38:548–554. © 2012 Wiley Periodicals, Inc.