Twenty-four-hour thallium-201 late redistribution imaging enhances the detection of myocardial viability after myocardial infarction.
BACKGROUND
Thallium-201 (201Tl) myocardial perfusion imaging has been widely used for evaluation of myocardial ischemia/viability after myocardial infarction. The 3- to 4-h early redistribution imaging has underestimated a considerable part of viable myocardium, while the 24-h late redistribution imaging may enhance the detection of myocardial ischemia/viability, but remains controversial.


METHODS
Thirty-eighty patients with myocardial infarction underwent the initial, 3-h, and 24-h redistribution imaging after intravenous injection of 148-185 MBq 201Tl. Image quality analysis was performed using a four-grade model: excellent, good, moderate, and poor. The initial and 3-h images, the initial and 24-h images, and the 3- and 24-h images were compared double-blinded.


RESULTS
The 3- and 24-h images showed no significant differences in image quality according to the four-grade model (P=.3580). Out of the 194 abnormal segments based on the initial imaging, 60 (31%) segments improved by at least one grade on the 3-h imaging, while 86 (44%) segments improved by at least one 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=7.4235, P=.0064). There were 164 abnormal segments on the 3-h imaging, with an average 30% (48) segments improved by at least one grade on the 24-h imaging. There were 134 initial abnormal segments without any improvement on the 3-h imaging. Out of these segments, the 24-h late redistribution imaging detected additional redistribution in 30 segments, taking up 22%. The mean global score on the 3-h imaging significantly decreased compared to that on the initial imaging (t=5.71, P<.0001), and the mean global score on the 24-h imaging further decreased significantly compared to that on the 3-h imaging (t=6.28, P<.0001).


CONCLUSIONS
Twenty-four-hour late 201Tl imaging, with satisfactory image quality, enhances the detection of myocardial viability after myocardial infarction.
Yang
Xiang-Jun
XJ
Department of Cardiology, the First Affiliated Hospital of SooChow University, Suzhou City, 215000, 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; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes