Validaticon of Global and Segmental Left Ventr!cl - - - 7 -, C _', - Iractile Function Using Gated Planar Technedum-99m S3EtamE,! Myocardial Perfusion Ims

Objectives. The purpose of this study was to test the hypothesis that segmental wall motion analysis determined from gated planar technetium-99m sestamibi myocardial imaging is reproducible and agrees well with echocardiographic data. Background. Technetium-99in sestamibi is a new radiophar l macenfical recently approved for myocardial perfusion imaging . Its advantages include a dosimetry that allows use of a dose 10 to 15 times higher than that of thallium-201. As a result, myocardial counts are markedly improved and images can be collected in a gated mode to potentially allow assessment of global and segmental ventricular function . However, the reproducibility and accuracy of technetiam-99m sestanlibi imaging for measurement of global and segmental left ventricular function have not been evaluated or compared with those of a standard ventricular function technique, such as echocardiography. Methods. We studied 136 patients referred for clinical technethim-99m sestamibi imaging . One-day rest-stress planar technetium-99m sestamibi protocols were used, gating the stress Technetium-99m sestamibi is a newly approved radiopharmaceutical for myocardial perfusion imaging that has several advantages over thallium-201 . The shorter half-life of only 6 h of technetium-99m results in a dosimetry that allows injection of doses 10 to 15 times higher than those of thallium-201 (1,2) . In combination with its higher energy, this results in substantially improved imaging characteris-tics.