Abstract

Background: Advances in myocardial perfusion imaging (MPI), including CT attenuation correction (CTAC) and advanced image reconstruction algorithms, result in improved image quality, thus reducing equivocal or false positive results. This theoretically decreases the need for downstream testing; however, there is limited access to these technologies due to their costs and the magnitude of benefit remains unclear. We performed an observational study to evaluate the effect of implementing a SPECT/CT system with advanced image reconstruction algorithms on diagnostic accuracy of MPI, and its effect on downstream healthcare expenditures. Methods: 277 consecutive patients who underwent SPECT MPI with a traditional SPECT camera were compared to 273 patients imaged at the same institution with a new SPECT/CT system with advanced image reconstruction algorithms. Accuracy of MPI was assessed in a subgroup of 36 and 26 consecutive patients in the traditional SPECT and SPECT/CT groups respectively, who underwent clinically-indicated invasive coronary angiography (ICA). Utilization of medical services related to coronary artery disease (CAD) was tabulated for the year following SPECT MPI and mean cost of services was estimated using national Medicare reimbursement data. Results: MPI studies performed on the SPECT/CT system were more likely to be overall true positive (62% vs. 25%; p = 0.008) and less likely to be false positive (19% vs. 56%; p = 0.004). Fewer false positive MPI studies resulted in fewer patients undergoing diagnostic ICA procedures (4% vs. 9%; p = 0.03). Among patients with additional CAD-related services within one year, total downstream healthcare cost was not significantly decreased, but mean expenditure on diagnostic healthcare services was lower in the SPECT/CT group ($4288 vs. $5740; p = 0.04). Conclusions: Use of SPECT/CT with advanced image reconstruction software for MPI can result in more efficient downstream utilization of diagnostic ICA and reduced downstream diagnostic expenditures.

Authors and Affiliations