A comparative study of whole body DWIBS MRI versus bone scan for evaluating skeletal metastases.

BACKGROUND Skeletal metastases in oncology patients are identified by Bone scan and/Positron Emission Tomography (PET) scan. But developing countries in the world still lack adequate numbers of these imaging facilities. AIMS Since Magnetic Resonance Imaging (MRI) is widely available as compared to bone scan or PET scan; a double blind study was undertaken to see if whole body imaging with MRI can give an idea of skeletal metastases. METHOD Diffusion weighted whole body Magnetic Resonance Imaging with background body signal suppression (DWIBS) was performed using 1.5 Tesla (T) MRI on histopathologically proven cases of carcinoma of breast within two months of mastectomy and followed up after a year of surgery. Similarly bone scan was also performed in these patients. RESULTS DWIBS MRI demonstrated the presence and extent of bone metastases in 10 out of a total 18 patients included in study while bone scan could demonstrate them in only three cases. A highly significant difference between proportions of the skeletal metastases detected by whole body DWIBS-MRI than that by bone scan at one year follow-up. (i.e. p<0.01, z=2.66) was seen. CONCLUSION DWIBS MRI scores high in demonstrating skeletal metastases. Further comparative studies are necessary to evaluate if DWIBS can replace bone scan or PET scan.