Myocardial perfusion in patients with suspected coronary artery disease: comparison between 320-MDCT and rubidium-82 PET

Abstract

Objectives: Despite advances in non-invasive myocardial perfusion imaging (MPI) evaluation, computed tomography (CT) multiphase MPI protocols have not yet been compared with the highly accurate rubidium-82 positron emission tomography (⁸²RbPET) MPI. Thus, this study aimed to evaluate agreement between ⁸²RbPET and 320-detector row CT (320-CT) MPI using a multiphase protocol in suspected CAD patients.

Methods: Forty-four patients referred for MPI evaluation were prospectively enrolled and underwent dipyridamole stress ⁸²RbPET and multiphase 320-CT MPI (five consecutive volumetric acquisitions during stress). Statistical analyses were performed using the R software.

Results: There was high agreement for recognizing summed stress scores ≥ 4 (kappa 0.77, 95% CI 0.55-0.98, p < 0.001) and moderate for detecting SDS ≥ 2 (kappa 0.51, 95% CI 0.23-0.80, p < 0.001). In a per segment analysis, agreement was high for the presence of perfusion defects during stress and rest (kappa 0.75 and 0.82, respectively) and was moderate for impairment severity (kappa 0.58 and 0.65, respectively). The 320-CT protocol was safe, with low radiation burden (9.3 ± 2.4 mSv).

Conclusions: There was a significant agreement between dipyridamole stress 320-CT MPI and ⁸²RbPET MPI in the evaluation of suspected CAD patients of intermediate risk. The multiphase 320-CT MPI protocol was feasible, diagnostic and with relatively low radiation exposure.

Key points: • Rubidium-82 PET and 320-MDCT can perform MPI studies for CAD investigation. • There is high agreement between rubidium-82 PET and 320-MDCT for MPI assessment. • Multiphase CT perfusion protocols are feasible and with low radiation. • Multiphase CT perfusion protocols can identify image artefacts.

Keywords: Coronary artery disease; Myocardial perfusion imaging; Positron emission tomography; Rubidium radioisotopes; Tomography.