The optimum injection-to-scan interval for spinal scans using⁸⁷Srm

In bone scans performed 45 minutes after injection of 87Srm an abnormal accumulation was noted in the region surrounding the lower dorsal spine This was unrelated to neoplastic or other pathological changes and is considered to be due to the high blood concentration of isotope after this interval and to an increase in the volume of blood within the sensitive volume of the detector Serial measurements over several sites indicated that inhomogeneity of this type would be minimized if the injection to scan interval were increased to three to four hours. Caution is recommended in interpreting any scan where blood concentration is high and inhomogeneities in blood distribution occur within the scan site.