SMALL HEPATOCELLULAR-CARCINOMA - DIFFERENTIATION FROM ADENOMATOUS HYPERPLASIA WITH COLOR DOPPLER US AND DYNAMIC GD-DTPA-ENHANCED MR-IMAGING

Background: To investigate the usefulness of color Doppler ultrasound (US) and dynamic Gd-DTPA-enhanced magnetic resonance (MR) imaging in t he differentiation of small hepatocellular carcinoma (HCC) and adenoma tous hyperplasia (AH). Methods: Thirty-eight small (3 cm or less) nodu lar lesions (in 38 cirrhotic patients) with US features consistent wit h HCC underwent evaluation with color Doppler US and MR imaging. Breat h-hold T1-weighted rapid acquisition spin echo MR sequence after bolus injection of 0.1 mmol/kg gadopentetate dimeglumine was used to evalua te dynamic enhancement. US-guided tissue-core percutaneous biopsy esta blished the diagnosis: HCC in 28 cases and AH in 10. Results: Color si gnals with pulsatile or continuous Doppler spectrum were demonstrated in 19 of 28 HCCs (68%) but in none of the AHs. Although there was cons iderable overlap in signal intensity between HCC and AH on both unenha nced T1- and T2-weighted images, early enhancement on breath-hold T1-w eighted images obtained 40 s after starting contrast administration wa s observed in 22 of 28 HCCs (79%) but in none of the AHs. In 26 of 28 HCCs (93%), pulsatile or continuous flow at color Doppler US, early en hancement at dynamic MR imaging, or both were observed. Conclusion: Fi ndings with color Doppler US and dynamic Gd-DTPA-enhanced MR imaging e nable a reliable distinction between small HCC and AH.