Imaging Features of Hepatocellular Carcinoma: Quantitative and Qualitative Comparison Between MRI-Enhanced With Gd-EOB-DTPA and Gd-DTPA Objectives The aim of this study was to compare the major imaging features of hepatocellular carcinoma (HCC) on magnetic resonance imaging (MRI) scans with Gd-EOB-DTPA (EOB) and extracellular agent (ECA; Gd-DTPA) contrast media. Materials and Methods Among 184 surgically proven HCCs in 169 patients who underwent a liver MRI with either EOB (n = 120) or ECA (n = 49), 55 HCCs were matched according to tumor size, Edmonson grade (major and worst), and gross type for each of the 2 contrast media. For the qualitative analysis, 2 board-certified radiologists independently reviewed arterial phase hyperenhancement, hypointensity on portal venous phase, hypointensity on delayed or transitional phase (DP/TP, 120–150 seconds), and capsule appearance. For the quantitative analysis, a third radiologist measured the signal intensity at each phase by placing the region of interest for tumor and normal liver parenchyma. The lesion-to-liver contrast (LLC) and lesion-to-liver contrast enhancement ratio (LLCER) were calculated. Results On qualitative analysis, hypointensity on DP/TP was seen more frequently with EOB (91% in reader 1, 89% in reader 2) than with ECA (73% in reader 1, 75% in reader 2; P = 0.026). Capsule appearance was seen less frequently with EOB (31% in reader 1, 44% in reader 2) than with ECA (73% in reader 1, 78% in reader 2; P < 0.001). On quantitative analysis, the LLC on arterial phase (AP) was better with ECA (P = 0.003), whereas LLC on DP was better with EOB (P < 0.001). The LLCER from precontrast to AP was higher with ECA (P = 0.022), whereas the LLCER from portal venous phase to DP was higher with EOB (P < 0.001). Conclusions ECA-MRI revealed better LLC on AP and detection rate of capsule appearance than EOB-MRI. EOB-MRI showed superior LLC on TP. Received for publication December 27, 2018; and accepted for publication, after revision, February 18, 2019. Jinwoo Son and Shin Hye Hwang contributed equally to this study. Conflicts of interest and sources of funding: none declared. Correspondence to: Mi-Suk Park, MD, PhD, Department of Radiology, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonse-ro, Seodaemun-gu, Seoul 03722, South Korea. E-mail: radpms@yuhs.ac. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.