Comparison of diagnostic performance of myocardial perfusion scintigraphy with and without attenuation correction.

INTRODUCTION: Myocardial perfusion scintigraphy (MPS) is an important diagnostic test for detection of coronary artery stenosis (CAS); however, tissue attenuation can lead to a difference in accuracy. We aimed to evaluate the diagnostic accuracy of attenuation-corrected (AC) and non-attenuation-corrected (NC) MPS for detection of CAS.
METHODS: We retrospectively recruited patients who underwent invasive coronary angiography within 10 months after 99mTc-sestamibi MPS. The AC and NC perfusion images were separately analyzed and each myocardial segment was scored based on relative uptake from 0 to 4. The summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were calculated. The diagnostic performances were analyzed using the area under the curve (AUC) of the receiver operating characteristic curve.
RESULTS: From 117 patients, significant coronary stenosis was present in 66 patients (56%). The SSS and SRS obtained from NC-images were higher than those from AC, supported the presence of attenuation artifacts in NC images. The AUC of SSS and SDS were significantly higher than those of SRS in both AC- and NC-images, but no significant difference was found between the AUC of SSS, and those of SDS. The optimal cutoffs were >12 for AC-SSS, >15 for NC-SSS, >4 for AC-SDS and >3 for NC-SDS. There was no statistically significant difference of the sensitivity, specificity, PPV, NPV and accuracy among AC-SSS, NC-SSS, AC-SDS and NC-SDS.
DISCUSSION AND CONCLUSION: NC-based 99mTc-sestamibi MPS promised comparable accuracy to AC images by using different cutoff values for diagnosis.