Prospective diagnostic performance of semiconductor SPECT myocardial perfusion imaging: wall thickening analysis reduces the need for an additional prone acquisition

PurposeTo determine whether the assessment of regional wall thickening (WT) in addition to myocardial perfusion from stress supine acquisitions could compensate for the lack of prone acquisition and the corresponding decrease in the diagnostic performance of SPECT myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease (CAD).MethodsThe study group comprised 41 patients (123 vessels) with known or suspected CAD prospectively recruited for systematic prone and supine Tl-201 stress SPECT MPI. The diagnostic performance of SPECT MPI was determined for various image sets including nongated supine images (supine NG), nongated combined prone and supine images (prone and supine NG) and gated supine images, allowing WT evaluation from NG images in addition to perfusion (supine NG+WT) using invasive coronary angiography and fractional flow reserve as the gold standards.ResultsThe rate of false positives was significantly higher among the supine NG images (20.8%) than among either the prone and supine NG or the supine NG+WT images (3.3% and 2.7%, respectively, P<0.05 vs. supine NG). Consequently, specificity was higher for the prone and supine NG images than for the supine NG images (96.1% vs. 76.1%, P<0.01) and was highest for the supine NG+WT images (96.8%, P not significant vs. prone and supine NG), without significant differences in sensitivity (80.0%, 86.6% and 73.3%, respectively, P not significant for all comparisons).ConclusionThe diagnostic performance of supine stress SPECT MPI is improved when WT assessment of ischaemic segments is used as an additional diagnostic criterion to values not significantly different from those with combined prone and supine acquisitions.