Assessment of myocardial viability in patients with myocardial infarction using twenty-four hour thallium-201 late redistribution imaging.
BACKGROUND
Rest thallium-201 (201Tl) myocardial perfusion imaging has been widely used for evaluation of myocardial ischemia/viability after myocardial infarction, but the ideal timing for imaging after injection to maximally estimate viability is not well established.


METHODS
Thirty-six patients with myocardial infarction underwent the initial, 3 h, and 24 h redistribution imaging after intravenous injection of 148-185 MBq 201Tl. The initial and 3 h images, the initial and 24 h images, and the 3 and 24 h images were compared double-blinded.


RESULTS
Out of the 184 abnormal segments based on the initial imaging, 56 (30%) segments improved by at least 1 grade on the 3 h imaging while 78 (42%) segments improved by at least 1 grade on the 24 h imaging. The 24 h late imaging detected more viable myocardium than the 3 h imaging did, with a significant difference (chi2= 5.680, p = 0.017). There were 158 abnormal segments on the 3 h imaging, with average 28% (44) segments improved by at least 1 grade on the 24 h imaging. There were 128 initial abnormal segments with no improvement on the 3 h imaging. Out of these segments, the 24 h late redistribution imaging detected additional redistribution in 26 segments, taking up 20%.


CONCLUSIONS
Twenty-four hour late 201Tl imaging will demonstrated additional redistribution in patients who have incompletely reversible defects on early redistribution imaging at 3h.
Department of Cardiology, First Affiliated Hospital of Soochow University, Jiangsu Province, China. yxjdemail@163.tom.com
Xiang-Jun
XJ
Yang
Yong-Ming
YM
He
Bin
B
Zhang
Yi-Wei
YW
Wu
Jie
J
Hui
Ting-Bo
TB
Jiang
Jian-Ping
JP
Song
Zhi-Hua
ZH
Liu
Wen-Ping
WP
Jiang
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013793:Thallium / Q000378:metabolism; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism
D019275:Radiopharmaceuticals; C027549:thallium chloride; D013793:Thallium