Quantification Of Myocardial Perfusion SPECT Studies In Chinese Local Population With Western Normal Database In The Detection Of Coronary Artery Disease

Background: Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a widely accepted test for diagnosis and prognosis of coronary artery disease (CAD). The success of SPECT MPI is, in part, thanks to the quantification techniques as an aid to visual image interpretation. Currently, validated computer software packages are available on almost all SPECT system. All of the software packages carry their specific normal databases, which are required for accurate quantification and mainly based on Western population. Due to significantly discrepancy in body characteristic, the accuracy of the Western normal databases has not been determined when applied to Chinese population.Objective: The purpose of this study is to assess diagnostic performance of the current quantification packages using Western normal databases in detecting coronary artery disease in Chinese population.Methods: 75 patients, who underwent rest/stress myocardial perfusion SPECT and coronary angiography (CAG), were enrolled. Emory Cardiac Toolbox (ECTb) and Quantitative Perfusion SPECT (QPS) with its standard (QPS-standard) and simplified (QPS-simple) methods were used to quantify these studies. A local normal database was created from 80 normal subjects (QPS-simple-local).The parameter of Extent (EXT) was generate for all the databases and Total perfusion defect (TPD) was yielded only for QPS-simple and QPS-simple-local. Receiver operator characteristic (ROC) was used to assess the accuracy of the four normal databases in detecting≥50% or≥70% stenosis given by CAG.Results: The enrolled cohorts had lower body mass index (BMI) and smaller heart size than Western population. The areas under ROC curve(AUC) of ECTb, QPS-standard, and QPS-simple were significantly lower than QPS-simple-local in detecting≥50% stenosis(the respective AUC was 0.74±0.06, 0.69±0.06, 0.78±0.06and 0.81±0.06 for EXT measure, and 0.77±0.06 and 0.84±0.05 for TPD measure; p<0.05 for all the comparison between Western normal databases and local database), but not in detecting≥70% stenosis.Conclusion: Quantification of MPI using Western normal database is not as accurate as used in Western population. Chinese normal database is needed for accurately applying these quantification methods to Chinese population, especially for detecting moderate defects in regions with relatively greater attenuation impact. An alternative approach could be modification of the existing Western normal databases for low-BMI and/or small-heart subjects.