Introduction

Multiple myeloma and its related entities (Table 3.1) are a spectrum of disorders characterized by monoclonal proliferation of plasma cells, usually with associated excessive production and secretion of monoclonal proteins detectable in serum or urine. While their management relies much on clinical and laboratory derived parameters, imaging also plays an important role. The suspicion of myeloma may be raised when an incidental lytic bone lesion is identified on a radiological examination performed for other purposes. Skeletal survey with plain radiographs is one of the initial screening tests performed when there is a suspicion of myeloma. Imaging is essential in accurately characterizing the disease entity within the spectrum. In some circumstances, such as in solitary plasmacytoma, diagnosis may be confidently achieved only with bone or soft tissue biopsy under image guidance. In addition, imaging may provide important staging and prognostic information and allow evaluation of response to treatment.

The use of X-rays in the evaluation of myeloma has been documented as early as 1900. To this date, the skeletal survey has remained the first line imaging investigation of choice. The introduction of CT and body MRI systems in the 1970s and hybrid PET/CT imaging systems in the 1990s have expanded the armament of the radiologist. Paralleling these developments is our improving understanding of the pathophysiology of myeloma and the on-going development and refinement of therapeutic strategies. These advances have necessitated continual evolution and standardization of diagnostic, staging and response evaluation criteria. This chapter reviews the imaging techniques currently available in routine clinical practice.