We describe a new technique, known as coregistration imaging, which superimposes . 99m. Tc isotope bone scans on to plain radiographs. We used the technique selectively in cases in which the nuclear medicine physician, who reported the isotope scan, had difficulty in localising the anatomical site of the abnormality. In the forefoot, coregistration of isotope scans did not help to localise pathology; the scan alone gave sufficient detail. In 17 patients with pain in the hind- and