title: Immediate thallium re-injection after stress imaging for the detection of myocardial viability.
abstract: Myocardial perfusion imaging with thallium is an established method to assess the presence of ischaemic and viable myocardium. Using planar imaging, images acquired 1 h after immediate thallium re-injection have been shown to be comparable to those of 3 h redistribution. The aim of this study was to clarify this using SPET. Twenty patients with chronic coronary artery disease with at least two perfusion defects on post-exercise images participated in this study. All patients received thallium re-injection after post-stress SPET and all had 1 h, 3 h and 24 h redistribution imaging. The thallium myocardial tomograms were divided into 14 segments for each patient. A total of 78 segments were studied. When the frequency of reversibility on 1 h, 3 h and 24 h redistribution images is compared, of the 78 SPET defects 18 (23.1%) showed reversibility by 1 h, 34 (43.6%) by combined 1 h and 3 h imaging (P < 0.05) and 50 (64.1%) by combined 1 h, 3 h and 24 h imaging (P < 0.05). Our results show that, compared to 3 h images, images acquired 1 h after immediate thallium re-injection underestimate the extent of viable myocardial segments and the incidence of late reversibility was not reduced by the immediate re-injection of thallium.
authors.affiliation: Department of Nuclear Medicine, Baskent University, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Aktas
authors.forename: B
authors.initials: B
authors.lastname: Caner
mesh_terms: D000328:Adult; D000368:Aged; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D013794:Thallium Radioisotopes / Q000493:pharmacokinetics*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D013794:Thallium Radioisotopes