LAUSR

A 51-year-old man with myeloma was referred for shortness of breath. To assess a potential coronary ischemic etiology, regadenoson Tc-sestamibi SPECT MPI was performed. Acquisition images demonstrated uptake in the sternum and ribs (Figure 1, supplementalon-line-video). Non-attenuation corrected slices showed a partially reversible defect of the anteroseptal and anterior walls, suggesting ischemia in the left anterior descending distribution (Figure 2a). However, with attenuation correction (AC, Vantage Pro, Philips Medical Systems), the stress defect resolved (Figure 2b). Nevertheless, given various clinical factors, the patient underwent right and left heart catherization, at which time angiography was performed and showed no coronary artery disease (CAD). The MPI images were therefore reassessed. Vantage Pro AC differs from nonAC imaging in several ways, including iterative reconstruction (ITR) processing, as opposed to filtered backprojection (FBP) for non-AC images. Suspecting a potential ramp-filter artifact from bone activity overlying the heart, non-AC raw images were reprocessed using ITR, and the anteroseptal defect satisfactorily resolved (Figure 3).