Imaging of common benign solid liver tumors.

The imaging modalities currently used for radiologic detection and characterization of hepatic neoplasms include color Doppler sonography, helical computed tomography (plain, biphasic enhanced CT), magnetic resonance imaging (plain, gadolinium enhanced MR), radionuclide scintigraphy (Technetium RBC, sulfur-colloid, IDA scan), angiography, and image-guided percutaneous needle biopsy. MR imaging is probably better at characterizing lesions than CT scan, but the latter remains the modality of choice at many institutions due to the speed of acquisition and good contrast resolution inherent in the technique. Each of these modalities is useful, but accurate lesion detection and specific radiologic diagnosis is most often made in many patients with typical imaging features using a combination of examinations rather than with a single modality. In the remaining patients with atypical features, a definitive diagnosis is usually obtained by a needle biopsy. Table I summarizes the typical clinical and imaging findings of common benign solid liver tumors, with suggested further work-up and management. Future developments will focus on the use of special contrast agents in sonography and MRI for further evaluation and characterization of focal hepatic lesions. Emerging clinical applications of these special contrast agents have shown a promising future role for contrast-enhanced sonography and MRI as problem-solving examinations after inconclusive ultrasound and helical CT.