Key Points• Bone marrow abnormalities were detected in the AS of 196 consecutive symptomatic patients with MM.• Medullary abnormalities in the AS were associated with a poor prognosis, independent of other clinical parameters.We aimed to determine the clinical and prognostic significance of medullary abnormalities detected by low-dose whole-body multidetector computed tomography ( 1.12-3.31; P 5 .018) were independent predictors of progression-free survival. Age and focal (HR, 2.51; 95% CI, 1.14-5.56; P 5 .023) and diffuse (HR, 4.12; 95% CI, 1.74-9.77; P 5 .001) patterns were also independent predictors of OS. The addition of marrow pattern to preexisting risk factors was associated with a net reclassification improvement for predicting OS (to 0.37, P 5 .015). Medullary abnormalities in the AS (detected by low-dose whole-body MDCT) are associated with a poor prognosis, independent of other clinical variables.