Hepatocellular carcinoma on MR diffusion weighted imaging and dynamic contrast-enhanced imaging

Abstract

Objective To evaluate the findings of hepatocellular carcinoma (HCC) on DWI and dynamic Gd-DTPA-enhanced MR imaging. Methods Eighty one patients with chronic hepatitis or liver cirrhosis underwent both DWI and dynamic Gd-DTPA-enhanced MRI studies of the liver for HCC detection. MR data of were retrospectively analyzed. Two observers determined in consensus the location and the number of focal lesions. The signal manifestation of the lesions on DWI and dynamic Gd-DTPA-enhanced MR imaging were analyzed. Results DWI and Gd-DTPA-enhanced MR images detected 122 HCCs and 14 benign lesions. One hundred and sixteen HCCs(95.1%) showed hyperintensity on DWI and 6 HCCs in patients with severe cirrhosis showed isointensity. One hundred and five HCCs (86. 1%) revealed hypointensity, 11 HCCs (9.0%) showed is)intensity and 6 HCCs (4.9%) exhibited hyperintensity on T1weighted images. On Gd-DTPA-enhanced MR images,101 HCCs(82. 8%) were significantly enhanced on arterial phase and 99 HCCs showed hypointensity on portal and equilibrium phases. Twenty HCCs (16. 4%), 18 of 20 less than 20 mm in diameter, showed isointensity on arterial phase and hyperintensity on DWL Eight of 14 benign lesions showed hyperintensity and 6 isointensity on DWI. Five benign lesions ,with hypointensity on T1 weighted images without contrast and hyperintensity on DWI showed no enhancement on Gd-DTPA-enhanced MR images;6 benign lesions with isointensity on both T1 weighted imaging without contrast and DWI exhibited avid enhancement on arterial phase and isointensty on portal and equilibrium phases;one of the two benign lesions, with isointensity before and after contrast images and hyperintentiy on DWI, was a regenerative nodule;another regenerative nodule with hyperintensity on both T1 weighted images without contrast and DWI was greatly enhanced on arterial phase and showed isointensity on portal and equilibrium phases. Conclusions Most of the HCCs were greatly enhanced on arterial phase on Gd-DTPA-enhanced MR imaging and some smaller HCCs showed isointensity on arterial phase and hyperintensity on DWI. The combination of DWI and Gd-DTPA-enhanced MR imaging may help to accurately diagnose HCCs. Key words: Liver neoplasms; Diffusion magnetic resonance imaging