Methods A random sampling of patients having a bone scan between October 2009 and July 2010 within NorthShore University HealthSystem were retrospectively reviewed using our electronic medical record (EPIC). Patients who had at least two Tc99m MDP bone scans during this period where the dose varied by at least 2mCi, had no infiltration of the dose, and had no irregular femur uptake were included in this study for a total of 30 patients. The patients’ bone scans were then analyzed to determine if there was any significant difference in the count density of the bones between patient’s “higher dose” scan and the “lower dose” scan. The count density was determined by first finding the half way point between the femoral head and patella on each femur, and then drawing a region of interest (ROI) on this spot. The average counts of the ROIs were recorded. This was repeated for both femurs on each of the bone scans. The percent difference between the average femoral counts for the high dose and low dose scans was calculated for the right and left femur separately for each patient. These two data sets were plotted against the percent difference of the dose for each individual patient. An r squared value was obtained for both plots.