Focal Hepatic Nodules with High Signal Intensity on T1-weighted MR Imaging: Differentiation of Small Hepatocellular Carcinoma from Dysplastic Nodule by Quantitative Analysis of Multi-phase Contrast-enhanced DynamicMR Imaging

Hyperintense nodules on non‐enhanced T1‐weighted gradient‐echo magnetic resonance imaging of cirrhotic liver: Fate and clinical implications

“…To determine the hypervascularity of enlarged nodules, lesion‐to‐liver contrast‐to‐noise ratios (CNRs) using a spherical region of interest (ROI) were measured. Compared to the CNR on the precontrast images, the lesions with increased CNR on the arterial phase images were regarded to have hypervascularity distinguished from the surrounding hepatic parenchyma (14, 21). Depending on the measured values, the lesion size change and hypervascularity of enlarged lesions was determined by consensus by the same radiologists.…”

“…Without T2w hyperintensity or arterial phase enhancement during dynamic imaging, T1‐weighted (T1w) hyperintense nodules are diagnostically challenging in daily practice due to their distinguished appearance from the cirrhotic background. Some investigators have claimed that T1w hyperintensity on precontrast MRI is a finding that is specific to dysplastic nodules (also termed adenomatous hyperplasia or macroregenerative nodules) in conjunction with T2w hypointensity (3, 14–17). Some HCCs, including small or well‐differentiated lesions, also show T1w hyperintensity and iso‐ or hypointensity on T2w images in explanted liver studies (1, 2, 9, 11).…”