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.
Yang
Xiang-Jun
XJ
Department of Cardiology, First Affiliated Hospital of Soochow University, Jiangsu Province, China. yxjdemail@163.tom.com
He
Yong-Ming
YM
Zhang
Bin
B
Wu
Yi-Wei
YW
Hui
Jie
J
Jiang
Ting-Bo
TB
Song
Jian-Ping
JP
Liu
Zhi-Hua
ZH
Jiang
Wen-Ping
WP
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