Sung Mo Kim1, Sang Soo Shin2,3, Byung Chan Lee4, Jin Woong Kim4, Suk Hee Heo4, Hyo Soon Lim4, Yong Yeon Jeong4. 1. Department of Radiology, Military Manpower Administration, Daejeon, South Korea. 2. Department of Radiology, Chonnam National University Hospital, Chonnam National University Medical School, 42 Jebong-ro, Dong-gu, Gwang-Ju, 61469, South Korea. kjradsss@dreamwiz.com. 3. Center for Aging and Geriatrics, Chonnam National University Medical School, Gwangju, South Korea. kjradsss@dreamwiz.com. 4. Department of Radiology, Chonnam National University Medical School, Gwangju, South Korea.
Abstract
PURPOSE: To prospectively compare multidetector-row CT (MDCT) and MR imaging (MRI) in the assessment of the ablative margin (AM) and index tumor immediately after radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) and assess whether non-contrast MRI with limited sequences (T1- and T2-weighted imaging only) was superior to a conventional MDCT protocol. METHODS: A total of 33 consecutive patients with 42 HCCs were included in this study. Both MDCT and MR images were independently reviewed by two radiologists regarding the ability to visually discriminate between the AM and index tumor, and the AM status within ablation zones. The AM status was classified as AM-plus (AM completely surrounding the tumor), AM-zero (AM was partly discontinuous, without protrusion of the tumor), and AM-minus (AM was partly discontinuous, with protrusion of the tumor). During the follow-up period, the cumulative local tumor progression rates were analyzed using the Kaplan-Meier method and Cox proportional hazards model. To determine the added value of contrast-enhanced MR images, both reviewers separately evaluated the two sets (unenhanced and enhanced) of MR images. RESULTS: Visual discrimination between the AM and index tumor was possible in four (9.5%) and 34 (81%) of the 42 ablation zones using MDCT and MRI, respectively (p < 0.001). Thirty-eight and four cases were classified as AM-plus and AM-zero on MDCT images, respectively, whereas the ablation zones were categorized as AM-plus (n = 32), AM-zero (n = 9), and AM-minus (n = 1) when examining the MR images. The cumulative incidence of local tumor progression was significantly lower in cases with AM-plus on MRI (p = 0.007). Contrast-enhanced MRI had no added value for the assessment of the AM and index tumor. CONCLUSION: MRI was superior to MDCT for the differential assessment of the AM and index tumor immediately after RF ablation for HCC. Non-contrast MRI was also superior to the conventional MDCT protocol.
PURPOSE: To prospectively compare multidetector-row CT (MDCT) and MR imaging (MRI) in the assessment of the ablative margin (AM) and index tumor immediately after radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) and assess whether non-contrast MRI with limited sequences (T1- and T2-weighted imaging only) was superior to a conventional MDCT protocol. METHODS: A total of 33 consecutive patients with 42 HCCs were included in this study. Both MDCT and MR images were independently reviewed by two radiologists regarding the ability to visually discriminate between the AM and index tumor, and the AM status within ablation zones. The AM status was classified as AM-plus (AM completely surrounding the tumor), AM-zero (AM was partly discontinuous, without protrusion of the tumor), and AM-minus (AM was partly discontinuous, with protrusion of the tumor). During the follow-up period, the cumulative local tumor progression rates were analyzed using the Kaplan-Meier method and Cox proportional hazards model. To determine the added value of contrast-enhanced MR images, both reviewers separately evaluated the two sets (unenhanced and enhanced) of MR images. RESULTS: Visual discrimination between the AM and index tumor was possible in four (9.5%) and 34 (81%) of the 42 ablation zones using MDCT and MRI, respectively (p < 0.001). Thirty-eight and four cases were classified as AM-plus and AM-zero on MDCT images, respectively, whereas the ablation zones were categorized as AM-plus (n = 32), AM-zero (n = 9), and AM-minus (n = 1) when examining the MR images. The cumulative incidence of local tumor progression was significantly lower in cases with AM-plus on MRI (p = 0.007). Contrast-enhanced MRI had no added value for the assessment of the AM and index tumor. CONCLUSION: MRI was superior to MDCT for the differential assessment of the AM and index tumor immediately after RF ablation for HCC. Non-contrast MRI was also superior to the conventional MDCT protocol.
Authors: Ijin Joo; Kenneth W Morrow; Steven S Raman; Justin P McWilliams; James W Sayre; David S Lu Journal: Eur Radiol Date: 2022-04-07 Impact factor: 7.034