Panel Disdussion

3rd International Congress 3rd International of Nuclear Congress Medicine of Nuclear & 15th Medicine Iranian Annual & 15th Iranian Congress Annual of
Nuclear Congress Medicine of Nuclear Medicine
Shahid Beheshti Shahid Beheshti University University of Medical Sciences of Medical 19-21 Sciences May 201119-21 May 2011
99mTc-MIBI INFUSION VERSUS NITROGLYCERIN 99mTc-MIBI
ON DETECTION OF MYOCARDIAL VIABILITY
Shahram Dabiri Oskoei 1 , Babak Mahmoudian 2
1 Tabriz University of Medical Science, Department of Nuclear Medicine
2 Tabriz Gamma Scan Nuclear Medicine Center
Objectives: Several studies have suggested that, rest 99mTc-MIBI
underestimates the extent of viable myocardium. This study aimed to
test whether 99mTc-MIBI infusion could increment the capacity of
99mTc-MIBI to detect myocardial viability and to compare it with
sublingual administration of nitroglycerine (TNG) before 99mTc-MIBI
injection in the same sample.
Method: Twenty patients (14 men, 6 women, mean age 51.5 ± 9.5
years) with previous myocardial infarction (mean evolution 6.5 ± 4
months) were submitted to myocardial perfusion scan with 99mTc-
MIBI gated SPECT for evaluation of myocardial viability. Rest
imaging, TNG 99mTc-MIBI scan and infusion of 99mTc-MIBI during
30 minutes were performed in all patients. Acquisition was started 60
minutes after starting of radiotracer infusion or injection. The uptake
more than 50% of maximum activity on each segment of bull’s eye
images was considered as viable tissue. Increased uptake more than
5% in comparison to rest study was considered significant.
Results: A total of 660 myocardial segments were analyzed, of which
112(17%) showed viability on rest images. Viable tissue was
observed in 135 segments (20.4%) on rest TNG99mTc-MIBI scan
with significant increased uptake in 16 (2.4%) other segments. After
99mTc-MIBI infusion, viability was seen on 132 segments (20%) and
significant increased uptake in 18 (2.7%) other segments. All above
mentioned segments were hypokinetic.
Conclusion: Resting 99mTc-MIBI infusion imaging, with improved
tracer delivery, may overcome some of the inadequacies of standard
stress/rest 99mTc-MIBI imaging for assessing myocardial viability.
The implication of this observation is that resting 99mTc-MIBI
infusion scintigraphy can provide useful information when evaluating
patients for the presence of hibernating myocardium. A prospective
comparison of resting 99mTc-MIBI infusion scintigraphy with other
noninvasive techniques which are used to identify viable myocardium
may thus be warranted.
Keywords: Myocardium, Perfusion, SPECT, MIBI, Infusion, Viability
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