Hypoechoic Lesions without Halo in Echogenic Liver

Sonographic evaluation for the presence of hypoechoic hepatic lesions without halo was carried out in 365 consecutive patients with echogenic livers. In 115 patients (31 %) such lesions could be demonstrated. Computed tomography of the liver was performed in 52 of these patients, a long term sonographic follow-up in 76, and a biopsy in 3 cases. In 103 patients the hypoechoic lesions were due to sonographic pseudolesions (PL's), probably representing normal liver tissue in otherwise diffusely fatty infiltrated livers. The PL's showed characteristic sonographic appearances such as a missing mass effect, a ‘landscape’-like configuration with angulated margins and slender extensions of hypoechoic tissue. The PL's were located below the capsule, near the gallbladder (41%), and ventral to the portal vein (37%). In 75 per cent they occurred in a liver with considerably increased echogenicity. In 12 patients hypoechoic lesions were caused by circumscribed malignant or infectious involvement of the liver. They could be discriminated from PL's by their mass-like appearance in 8 subjects. In 4 of these 12 cases the foci were of PL-typical appearance, but not of PL-typical location. In the light of these results and of recently published reports a rational diagnostic approach to hypoechoic lesions without halo in echogenic livers varies, depending on such factors as known primary malignancy or site of the lesion.