Authors: Edson L. Knapp, MD; Mark J. Kransdorf, MD; G. Douglas Letson, MD

Abstract

Background: No single imaging approach is ideal for every tumor. While radiography can be effective for diagnosis of specific tumors, additional imaging is often required. Soft tissue sarcomas require a multimodality approach.
Methods: The authors discuss the general imaging approaches for patients who present with soft tissue masses, the fundamental principles inherent to tumor imaging, and the specific applications of newer imaging modalities.
Results: Magnetic resonance imaging has emerged as the preferred technique for evaluating soft tissue tumors but is limited in demonstrating the pattern of soft tissue calcification. Computed tomography is the best modality for evaluating osseous architecture and for patients who cannot be evaluated with MRI. PET is helpful in metabolic imaging, and ultrasonography is useful in differentiating cystic from solid masses. Magnetic resonance angiography accurately reveals the arterial and venous supply of vascular tumors.
Conclusions: Current imaging techniques provide numerous noninvasive methods to diagnose and stage suspected soft tissue sarcomas.

Introduction

Soft tissue sarcomas are rare cancers. The American Cancer Society estimates that in 2004, approximately 8,680 new soft tissue sarcomas will be diagnosed in the United States.[1] Of these, 3,660 Americans are expected to die of their disease. While malignant soft tissue tumors are rare, benign tumors are not; it is estimated that there are 100 benign lesions for each sarcoma.[2]

The radiologic evaluation of a suspected soft tissue mass has changed dramatically with the advent of com-puter-assisted imaging. The currently available imaging modalities offer numerous noninvasive methods to diagnose and stage suspected soft tissue sarcomas. This article highlights the general imaging approach to patients presenting with soft tissue masses. It is not intended as a comprehensive review, but rather as an overview, emphasizing the fundamental principles inherent to tumor imaging and the specific applications of the newer imaging modalities.