Quantitative myocardial perfusion SPECT/CT for the assessment of myocardial tracer uptake in patients with three-vessel coronary artery disease: Initial experiences and results

BACKGROUND: To evaluate quantitative myocardial perfusion SPECT/CT datasets for routine clinical reporting and the assessment of myocardial tracer uptake in patients with severe TVCAD. METHODS: MPS scans were reconstructed as quantitative SPECT datasets using CTs from internal (SPECT/CT, Q_INT) and external (PET/CT, Q_EXT) sources for attenuation correction. TPD was calculated and compared to the TPD from non-quantitative SPECT datasets of the same patients. SUV(max), SUV(peak), and SUV(mean) were compared between Q_INT and Q_EXT SPECT datasets. Global SUV(max) and SUV(peak) were compared between patients with and without TVCAD. RESULTS: Quantitative reconstruction was feasible. TPD showed an excellent correlation between quantitative and non-quantitative SPECT datasets. SUV(max), SUV(peak), and SUV(mean) showed an excellent correlation between Q_INT and Q_EXT SPECT datasets, though mean SUV(mean) differed significantly between the two groups. Global SUV(max) and SUV(peak) were significantly reduced in patients with TVCAD. CONCLUSIONS: Absolute quantification of myocardial tracer uptake is feasible. The method seems to be robust and principally suitable for routine clinical reporting. Quantitative SPECT might become a valuable tool for the assessment of severe coronary artery disease in a setting of balanced ischemia, where potentially life-threatening conditions might otherwise go undetected. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12350-021-02735-2.