Abdomen: Solid Organs

Solid organs in the abdomen and pelvis are routinely imaged using cross-sectional imaging in current clinical practice. Differentiation of solid from cystic lesions is an important step in establishing benignity but can sometimes be challenging on ultrasound imaging and may require further evaluation with computed tomography (CT) and magnetic resonance imaging (MRI). Among solid lesions, morphological features can overlap, even between malignant and infectious conditions. We illustrate these pitfalls with the use of relevant case examples and discuss various state-of-the-art techniques, such as diffusion-weighted MRI, that may sometimes be helpful in improving specificity. By understanding the limitations of current techniques, the reader should know when to recommend invasive procedures, such as percutaneous biopsies, in the management of such difficult cases.