Significance of late redistribution thallium-201 imaging after rest injection for detection of viable myocardium.
The aim of this study was to determine whether late redistribution imaging after rest injection of 201Tl would provide further information on myocardial viability over conventional rest-early redistribution 201Tl imaging.


METHODS
Twenty-nine patients with coronary artery disease and left ventricular dysfunction underwent rest, early (3-4 hr) and late (20-24 hr) redistribution 201Tl and gated blood pool studies. In 14 patients with successful revascularization, gated blood pool study was repeated after the coronary intervention.


RESULTS
Nine of 29 patients showed early redistribution, and six additional patients showed further redistribution on the late images. Of 136 segments with initial 201Tl defects, 18 showed early redistribution, and 10 showed late redistribution. When a threshold of 60% of peak activity was used as an index of myocardial viability, only a small fraction (3%) of the initial 201Tl defects were additionally considered viable by the late images. In 14 patients who underwent revascularization, the positive (69%) and negative (87%) predictive values of the early redistribution images for functional recovery were similar to those obtained by the late images (68% and 86%, respectively).


CONCLUSIONS
Although late redistribution after rest injection of 201Tl occasionally occurs, most of the clinically relevant information on myocardial viability may be obtained by conventional rest-early redistribution 201Tl imaging when the defect severity is considered an index of tissue viability.
Matsunari
I
I
Department of Radiology, Fukui Prefectural Hospital, Japan.
Fujino
S
S
Taki
J
J
Senma
J
J
Aoyama
T
T
Wakasugi
T
T
Hirai
J
J
Saga
T
T
Yamamoto
S
S
Tonami
N
N
D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011875:Radionuclide Angiography; D012146:Rest; D013794:Thallium Radioisotopes; D014022:Tissue Survival; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000628:therapy
D013794:Thallium Radioisotopes