Purpose: To evaluate the usefulness of chemical shift imaging (CSI) in differentiating benign osteoporotic and malignant vertebral marrow lesions. Material and methods:Patients undergoing spinal magnetic resonance imaging (MRI) for back pain, which showed altered marrow signal intensity on conventional MRI sequences, were included in the study. Patients with acute traumatic vertebral fractures, infective spondylodiscitis, paravertebral collections, etc. were excluded. The patients underwent CSI. In-phase and opposed-phase images were taken to calculate the signal intensity ratio (SIR) of the abnormal vertebra. The SIR of the mean signal intensity measured on opposed-phase to mean signal intensity measured on in-phase images was measured and recorded. Results:The studied population included 30 patients, in whom 58 vertebrae were accessed, which included 38 dorsal, 18 lumbar, 1 sacral, and 1 cervical. Out of 58 vertebrae, 46 (79%) were malignant and 12 (20%) were benign. The mean CSI/SIR of malignant lesions was 0.96 and the mean SIR of benign lesions was 0.76. Conclusions:Conventional MRI sequences cannot always differentiate between benign and malignant lesions. So newer sequences like CSI have been developed. CSI SIR can be used as a new tool in differentiating benign osteoporotic and malignant vertebral marrow lesions.