The normal bone scan

This paper discusses applications of the bone scan. It is the most frequently performed nuclear medicine investigation, the commonest indication being the detection of occult metastases, for which purpose the entire skeleton should be imaged. For other purposes it is often adequate to examine only part of the skeleton. The amount of isotope taken up at any site depends primarily on the local rate of bone turnover rather than on bone mass. The scintigraphic appearance therefore does not necessarily correlate with the radiographic one; however, as there is a relationship between the rate at which bone is replaced and the quantity of bone which is present at any point, the two appearances are not entirely unrelated. Recognition of abnormality is based on a detailed knowledge of normal scintigraphic appearances