the aim of this study was to establish whether hydration prior to radiopharmaceutical injection, in addition to post injection hydration, contributed any value to image quality during bone scintigraphy. two hundred patients referred for bone imaging over a four month period were randomised into two groups. group a was issued with instructions to hydrate pre and post injection, and group b was only advised to hydrate between injection and scan. equal regions of interest (roi) were then drawn on each image: firstly over the femoral diaphysis, and secondly over the contra-lateral adductor area. the total number of gamma counts from the bone roi and the soft tissue roi was then expressed as a ratio, and a mean value for each group was established.

the mean ratio for group a was found to be 2.25, and for group b 2.30. a t test of variance confirmed that there was no statistical difference between the ratios of the groups (t = 50.272, n = 5100, p = 50.618). it was concluded that hydration levels prior to bone scintigraphy injection, where it is preserved post injection, have no significant effect on the bone-soft tissue (b:st) ratio in the image.