Evaluation of technetium-99m-sestamibi lung uptake: correlation with left ventricular function.

Lung uptake of 201Tl is a reliable marker of left ventricular dysfunction. The goal of our study was to establish whether the evaluation of lung-to-heart uptake ratios (LHR) with 99mTc-sestamibi imaging may provide valuable information.

METHODS: We studied 72 male subjects with recent anterior myocardial infarction undergoing 99mTc-sestamibi first-pass ventriculography and SPECT perfusion imaging. A group of 46 gender-matched subjects with low pre-test likelihood of CAD and normal exercise and rest 99mTc-sestamibi perfusion images was used as a control. The lung-to-heart count ratios (LHR) were calculated on planar projections from the sets of SPECT images.

RESULTS: Both groups were studied at rest and after a symptom-limited exercise tolerance test. In the control group a significant decrease in LHR was observed during stress (p < 0.001). The infarcted group showed significantly higher LHR values both at rest and at stress. Exercise and rest LHR values did not differ significantly. A positive correlation was observed between LHR values and left ventricular ejection fraction at rest and stress.

CONCLUSION: LHR, measured by 99mTc-sestamibi imaging, gives clinically useful information. Both resting and postexercise values are correlated with ejection fraction and should predict left ventricular dysfunction.