Diagnostic efficacy of a low-dose 32-projection SPECT 99mTc-sestamibi myocardial perfusion imaging protocol in routine practice.
BACKGROUND
99mTc-labeled tracers can provide better imaging quality than does TI for myocardial perfusion imaging (MPI). Nevertheless, a large study showed no significant difference in diagnostic efficacy, implying that image quality, though not optimal, may be still adequate for reliable interpretation. We thus proposed a suboptimal low-dose 32-projection single-photon emission computed tomography (SPECT) 99mTc-sestamibi (99mTc-methoxyisobutylisonitrile) MPI protocol and evaluated its diagnostic efficacy.


METHODS
A total of 1007 patients undergoing the proposed rest-stress MPI protocol were included in the study for analysis. Among them, 218 had coronary angiography, which was used as the 'gold standard' for evaluating sensitivity and specificity. The normalcy rate was obtained from 47 patients with a low cardiovascular risk. The injected dosage for 99mTc-methoxyisobutylisonitrile resting and dipyridamole stress imaging is 185 and 555 MBq, respectively, with an interval of about 2 h between the two injections. Most of the patients completed the whole MPI within 3 h.


RESULTS
Using this protocol, the sensitivity and specificity of the 218 patients with subsequent coronary angiography for determining coronary artery disease were 95 and 63%, respectively. The normalcy rate was 87%. Both the rest and stress images were adequate for confident interpretation.


CONCLUSIONS
The proposed low-dose 32-projection SPECT protocol has a diagnostic efficacy comparable with that reported in the literature, most of which used a higher dose and 64-projection SPECT, with additional benefits of lower radiation exposure, lower cost, and shorter study time.
Wu
Ming-Che
MC
Department of Nuclear Medicine, Mackay Memorial Hospital, Taipei, Taiwan.
Chin
Kun-Chou
KC
Lin
Ku-Hung
KH
Chiu
Nan-Tsing
NT
D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi / Q000008:administration & dosage*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi