In Tc-99m MIBI scintimammography, the exact localization of foci of increas
ed tracer uptake or the exact anatomic correlation of palpated breast masse
s with a scintigraphic finding is difficult. The authors describe three pat
ients with known or possible malignant breast lesions for whom the use of e
xternal radioactive markers successfully helped to provide this information
, thus improving the diagnostic accuracy and guiding decisionmaking in the
patients' treatment.