Evaluation of focal fatty infiltration of the liver using color Doppler and contrast-enhanced sonography.

ABSTRACT

PURPOSE: To investigate the vascular characteristics of focal fatty infiltration (FFI) in the liver using color Doppler sonography (CDUS) and contrast-enhanced sonography (CEUS). METHODS: We prospectively examined 25 areas of FFI of the liver in 20 patients via conventional gray-scale sonography, CDUS, and CEUS. Cadence contrast pulse sequencing and the contrast agent SonoVue were used for CEUS examination. CEUS criteria for diagnosis of FFI were isoenhancement or hypoenhancement in the arterial phase and homogeneous isoenhancement in the portal and late phases. RESULTS: CDUS revealed a draining vein in 4 of 9 (44%) lesions in the hepatic hilum, whereas CEUS revealed a draining vein in 8 (89%) lesions. A vein was associated with the 2 lesions located at the edge of segment II on both CDUS and CEUS. Blood flow was seen on both CDUS and CEUS in the 2 lesions adjacent to the falciform ligament. In one patient, CDUS and CEUS revealed the mid-hepatic vein coursing between 2 FFIs. In the arterial phase of CEUS, the lesions were hypoenhancing in 44% (11/25), iso-enhancing in 44% (11/25), and hyperenhancing in 12% (3/25). In the portal phase and in the late vascular phase, all 25 lesions (100%) were iso-enhancing. Sensitivity of combined sonography and CDUS in the diagnosis of FFI was 44%, and overall accuracy was 81%. The sensitivity of CEUS in the diagnosis of FFI was 88%, and its overall accuracy was 96%. CONCLUSION: FFI in the porta hepatis is correlated with aberrant venous drainage. FFI around the falciform ligament may be related to divergence of the portal vein or unusual blood supply. In the arterial phase of CEUS, FFI lesions were iso-enhancing as often as they were hypoenhancing.