Amy Inji Chang1, Young Kon Kim2, Ji Hye Min3, Jisun Lee4, Honsoul Kim1, Soon Jin Lee1. 1. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul, 135-710, Republic of Korea. 2. Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul, 135-710, Republic of Korea. jmyr@dreamwiz.com. 3. Department of Radiology, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Republic of Korea. 4. Department of Radiology, Chungbuk National University Hospital, Cheongju, Republic of Korea.
Abstract
PURPOSE: To determine the differential features of inflammatory myofibroblastic tumor (IMT) and intrahepatic cholangiocarcinoma (ICC) manifesting as target appearance on gadoxetic acid-enhanced MRI. METHODS: Twenty-seven patients with 36 IMTs (1.2-6.0 cm) and 34 patients with 34 ICCs (1.5-6.0 cm) who underwent gadoxetic acid-enhanced MRI were enrolled in this study. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and gadoxetic acid-enhanced imaging. RESULTS: As for 32 IMTs with target appearance, IMTs most commonly demonstrated early target appearance characterized by a peripheral hypointense rim on unenhanced T1WI (n = 27, 84.4%), central enhanced area with a hypointense rim on arterial phase (AP) and portal venous phase (PVP) (n = 29, 90.6%), and transitional phase (TP) (n = 28, 87.5%). Meanwhile, most of the ICCs showed homogeneous hypointensity on T1WI (100%), a hyperenhancing rim on AP, late target appearance on TP (n = 32, 94.1%) and HBP (n = 32, 94.1%). Target appearance on DWI appearing as hyperintensity with central hypointense area was seen in 2 IMTs and 32 ICCs. On T2WI, 24 IMTs (n = 24, 75.0%) displayed central iso- and peripheral hyperintensity and 27 ICCs (84.4%) showed layered hyperintensity with either brighter or darker area in center. The remaining six IMTs with no target were observed as cystic appearing nodules (n = 3) or ill-defined hypovascular nodules (n = 2) and fibrotic mass (n = 1). CONCLUSION: IMTs often show early target appearance on unenhanced T1WI, and early dynamic phases of gadoxetic acid-enhanced MRI. Target appearance on later phases, such as TP and HBP, and DWI target appearance were commonly in ICCs, but rare in IMTs.
PURPOSE: To determine the differential features of inflammatory myofibroblastic tumor (IMT) and intrahepatic cholangiocarcinoma (ICC) manifesting as target appearance on gadoxetic acid-enhanced MRI. METHODS: Twenty-seven patients with 36 IMTs (1.2-6.0 cm) and 34 patients with 34 ICCs (1.5-6.0 cm) who underwent gadoxetic acid-enhanced MRI were enrolled in this study. Two reviewers evaluated morphology, signal intensity, and enhancement features of tumors on T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and gadoxetic acid-enhanced imaging. RESULTS: As for 32 IMTs with target appearance, IMTs most commonly demonstrated early target appearance characterized by a peripheral hypointense rim on unenhanced T1WI (n = 27, 84.4%), central enhanced area with a hypointense rim on arterial phase (AP) and portal venous phase (PVP) (n = 29, 90.6%), and transitional phase (TP) (n = 28, 87.5%). Meanwhile, most of the ICCs showed homogeneous hypointensity on T1WI (100%), a hyperenhancing rim on AP, late target appearance on TP (n = 32, 94.1%) and HBP (n = 32, 94.1%). Target appearance on DWI appearing as hyperintensity with central hypointense area was seen in 2 IMTs and 32 ICCs. On T2WI, 24 IMTs (n = 24, 75.0%) displayed central iso- and peripheral hyperintensity and 27 ICCs (84.4%) showed layered hyperintensity with either brighter or darker area in center. The remaining six IMTs with no target were observed as cystic appearing nodules (n = 3) or ill-defined hypovascular nodules (n = 2) and fibrotic mass (n = 1). CONCLUSION: IMTs often show early target appearance on unenhanced T1WI, and early dynamic phases of gadoxetic acid-enhanced MRI. Target appearance on later phases, such as TP and HBP, and DWI target appearance were commonly in ICCs, but rare in IMTs.