[Sources of error in the interpretation of bone scans with 99mTc-diphosphonate (author's transl)].

Errors in the interpretation of bone scans with 99mTc-diphosphonate may be due to summation of radio-activity from superimposition of various bone structures. Lesions with increased bone turn-over as well as reactive hyperaemia result in increased uptake. The possibility of extraosseous uptake of diphosphonate must be borne in mind during the evaluation of bone scans. The kidneys and lower urinary tract must be considered. Absent or slight uptake by the kidneys with good demonstration of bone suggests increased diphosphonate uptake by the bones. Special attention should also be paid to zones of decreased uptake, since these are also due to abnormalities in the bone.