[The value and limitation of resting 201Tl reinjection after stress-redistribution imaging for the assessment of myocardial viability: comparison with wall motion improvement by revascularization].
Clinical value and limitation of resting reinjection of small dose of thallium (37 MBq) for the assessment of myocardial viability were evaluated. The results were compared with the degree of wall motion improvement by revascularization to infarcted myocardium supplied by chronic total vessels in 12 patients with old myocardial infarction. Thallium uptake was visually scored and judged as normal, reversible defect (Group 1), new fill in after reinjection (Group 2A), and no fill in even after reinjection (Group 2B). Among 53 segments with initial perfusion abnormality, 21 segments reverted to almost normal, while 32 segments remained abnormal on redistribution images. New fill in after reinjection was observed in 11 segments of 32 segments showing persisting defect on stress and delayed image (37%). Wall motion score index of Group 2A improved significantly higher than Group 2B (p less than 0.01) and almost equal to Group 1, suggesting the utility of reinjection for the assessment of tissue viability which may be underestimated by conventional imaging. But significant wall motion improvement (greater than or equal to 0.6 mean SD/chords) was observed in 6 segments (29%) of 21 segments showing neither redistribution nor fill in after reinjection. These data indicate that small dose of thallium reinjection may enhance detection of viable but jeopardized myocardium, although some underestimation of viability remained to be resolved.
Matsuo
H
H
Department of Cardiology, Gifu Prefectural Hospital.
Watanabe
S
S
Kano
M
M
Mori
S
S
Nishida
Y
Y
Matsubara
T
T
Sugiyama
A
A
Matsuno
Y
Y
Oda
H
H
Kotoo
Y
Y
D000368:Aged; D000369:Aged, 80 and over; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000628:therapy; D009204:Myocardial Revascularization; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D013794:Thallium Radioisotopes / Q000008:administration & dosage; D014022:Tissue Survival; D015899:Tomography, Emission-Computed, Single-Photon
D013794:Thallium Radioisotopes