DEFECT REVERSIBILITY USING TL-201 REINJECTION

Immediate poststress thallium-201 reinjection followed by imaging one hour later has been proposed as an alternative reinjection protocol. T his procedure is patient-convenient and time-saving as it shortens the investigation time to maximally 2.5 hours. The efficacy of the immedi ate thallium-201 reinjection protocol was assessed in 305 patients wit h stress perfusion defects in whom we compared the scintigraphic findi ngs of 210 consecutive patients who underwent the standard thallium-20 1 stress/redistribution/reinjection protocol (Group I), with 95 consec utive patients who subsequently underwent the thallium-201 stress/imme diate reinjection protocol (Group II). In all patients three-view plan ar images were visually and quantitatively analyzed. In Group I, defec t reversibility was observed in 433 of 622 (70%) stress perfusion defe cts compared to 220 of 320 (69%) segments in Group II (p = NS). With r espect to Q-wave related segments, defect reversibility was seen in 10 2 of 172 (59%) segments in Group I compared to 34 of 63 (54%) in Group II (p = NS). Based on defect reversibility, the diagnosis of myocardi al ischemia was made in 184 of 210 (88%) patients Group I compared to 86 of 95 (91%) patients in Group II (p = NS). These findings indicate that immediate thallium-201 reinjection imaging provides at least simi lar data on defect reversibility as the standard thallium-201 stress/r edistribution/reinjection approach. In practical terms, the stress/imm ediate reinjection approach seems advantageous as it reduces imaging t ime, enhances patient throughout and can be considered as one comprehe nsive imaging procedure.