Imaging modalities and techniques in soft tissue tumours

Abstract

Imaging of soft tissue lesions requires a systemic approach. A careful review of the clinical history, prior imaging investigations, and clinical and surgical notes may help narrow the differential diagnoses. Ultrasound is the first modality of choice for evaluating soft tissue lesions. In addition to providing structural details, such as the solid, cystic or calcified nature of the lesion, it can also assess vascularity and anatomical relationships with vital structures. On the other hand, magnetic resonance imaging (MRI) is the modality of choice for soft tissue tumour imaging. It details tumour extension, relationships with adjacent structures, tissue characterisation, multicompartment spread and locoregional assessment. Computed tomography (CT) can be used when MRI is contraindicated; it delineates the presence of fat, fluid-fluid levels, solid components, necrotic areas and calcifications. PET-CT is especially useful in staging, restaging and assessing the treatment response of the tumours. It also has prognostic value. Plain radiographs hold limited value in characterising soft tissue sarcomas.