Bone lesions are present in approximately 80–85% of patients with multiple myeloma at diagnosis. The most common sites of osteolysis include the spine (49–70%), ribs (45–50%), skull (35–50%), shoulder (20–35%), pelvis (30–40%), and long bones (13–35%). Bone destruction results from asynchronous bone turnover, characterized by increased osteoclastic resorption without proportional osteoblastic activity. A specific feature is the rare healing of lesions, even in complete remission.
Low-dose whole-body computed tomography is currently the gold standard for bone disease assessment in multiple myeloma, offering superior sensitivity and image quality compared to conventional radiography, with a 4–33% higher detection rate. PET-CT shows 90% sensitivity and 70–100% specificity and remains essential for identifying active lesions, monitoring bone disease progression, and evaluating response to therapy, including residual disease detection. MRI allows differentiation between healthy marrow and infiltrated tissue, identifies infiltration patterns and lesion morphology, detects early bone marrow involvement, and surpasses bone scintigraphy in identifying spinal lesions, particularly in unexplained vertebral compression fractures.