Direct comparison of rest and adenosine stress myocardial perfusion CT with rest and stress SPECT

Abstract

Introduction: We have recently described a technique for assessing myocardial perfusion using adenosine-mediated stress imaging (CTP) with dual source computed tomography. SPECT myocardial perfusion imaging (SPECT-MPI) is a widely utilized and extensively validated method for assessing myocardial perfusion. The aim of this study was to determine the level of agreement between CTP and SPECT-MPI at rest and under stress on a per-segment, per-vessel, and per-patient basis.

Methods: Forty-seven consecutive patients underwent CTP and SPECT-MPI. Perfusion images were interpreted using the 17 segment AHA model and were scored on a 0 (normal) to 3 (abnormal) scale. Summed rest and stress scores were calculated for each vascular territory and patient by adding corresponding segmental scores.

Results: On a per-segment basis (n = 799), CTP and SPECT-MPI demonstrated excellent correlation: Goodman-Kruskall gamma = .59 (P < .0001) for stress and .75 (P < .0001) for rest. On a per-vessel basis (n = 141), CTP and SPECT-MPI summed scores demonstrated good correlation: Pearson r = .56 (P < .0001) for stress and .66 (P < .0001) for rest. On a per-patient basis (n = 47), CTP and SPECT-MPI demonstrated good correlation: Pearson r = .60 (P < .0001) for stress and .76 (P < .0001) for rest.

Conclusions: CTP compares favorably with SPECT-MPI for detection, extent, and severity of myocardial perfusion defects at rest and stress.

Figures

Figure 1

Patient recruitment. Out of 957 patients meeting inclusion criteria, 491 were excluded and 419 refused to participate. Forty-seven patients completed the CT stress perfusion scan. ACS Acute coronary syndrome, CABG coronary artery bypass grafting surgery.

Figure 2

Stress Myocardial CT Perfusion Protocol. See “Methods” section for further detail.

Figure 3

Radiation exposure of CT perfusion versus SPECT-MPI. Estimated effective radiation dose in milisivert (mSv) is displayed for CTP (solid bars) and SPECT (striped bars). The total effective radiation dose was not statistically different between the two modalities.

Figure 4

Example of correlation between CTP and SPECT. A 53-year-old male with a history of non-ST segment elevation myocardial infarction presenting with exertional chest pain. Short axis views at the mid-ventricular level of adenosine-mediated sestamibi SPECT showing large fully reversible perfusion defects of the lateral wall suggestive of moderate ischemia (panels A and C; white arrows). Short axis thick multiplanar reformatted (MPR) 8-mm thick slices at the mid-ventricular level of adenosine-mediated CTP showing extensive reversible perfusion defects of the lateral wall (panels B and D; white arrows).

Figure 5

Agreement of CTP and SPECT for the Assessment of Perfusion Defect Severity on a per-vessel and per-patient Basis Using 3 Ischemic Categories. Summed stress and scores (SSS) were used to categorize each of 141 vascular territories as mild (SSS of 0-3), moderate (SSS of 4-12), or severe (SSS of ≥13) (panel A). Summed rest scores (SRS) were similarly used to categorize territories as mild, moderate and severe (panel B). Summed rest and stress scores were then used to categories each of 47 patients as mild, moderate, or severe (panels C and D).