Myocardial redistribution of technetium-99m-methoxyisobutyl isonitrile (SESTAMIBI).
To determine whether technetium-99m-hexakis-2-methoxyisobutyl isonitrile (SESTAMIBI) remains fixed in the myocardium following its initial uptake or undergoes time-related redistribution, anesthetized dogs underwent occlusion of the anterior descending coronary artery for 6 min, followed by 3-hr reperfusion. Technetium-99m-SESTAMIBI and thallium-201 (201Tl) were injected intravenously after 1 min occlusion and regional myocardial blood flow was measured with radioactive microspheres. Tomographic imaging of Tc-SESTAMIBI revealed a perfusion defect with slight but definite filling in over 2 hr. Quantitative analysis indicated a significant rise in the nadir and decrease in the width of the defect in circumferential profile curves. After 3-hr of reperfusion, Tc-SESTAMIBI activity in the previously ischemic area was always greater than the activity of microspheres injected during coronary occlusion (mean normalized values, 0.32 versus 0.11, p less than 0.0001). Our results indicate that following transient ischemia and reperfusion, Tc-SESTAMIBI clearly undergoes myocardial redistribution, although more slowly and less completely than 201Tl.
Li
Q S
QS
Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland.
Solot
G
G
Frank
T L
TL
Wagner
H N
HN
Becker
L C
LC
D000818:Animals; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000628:therapy; D004285:Dogs; D005260:Female; D008297:Male; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D011877:Radionuclide Imaging; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes / Q000493:pharmacokinetics
D015609:Organotechnetium Compounds; D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi