Bone scan versus MRI for bone metastatases in breast cancer

The time course to the appearance of clinically detected distant metastases of breast cancer is extremely long. It is common for metastases to manifest 10 years or more after the initial diagnosis of breast cancer. It is generally accepted that least invasive methods for evaluating suspected metastases should be employed. The few studies that compared MRI, PET and bne scan found them to be simlarly effective. Bone scan is preferred to MRI in this regard since it is less invasive, less expensive and images the entire skeleton.P . Papagelopoulos , A . Mavrogenis , P . Soucacos Evaluation and treatment of pelvic metastases . 
Injury , Volume 38 , Issue 4 , Pages 509 - 520

Kosuda S, Kaji T, Yokoyama H, et al. Does bone SPECT actually have lower sensitivity for detecting vertebral metastases than MRI? J Nucl Med 1996; 37:975 -978

T. Hamaoka, J. E. Madewell, D. A. Podoloff, G. N. Hortobagyi, and N. T. Ueno
Bone Imaging in Metastatic Breast Cancer
J. Clin. Oncol., July 15, 2004; 22(14): 2942 - 2953.