Without physical corrections impacts the performance of myocardial blood flow quantitation with multi-pinhole CZT-SPECT

Abstract

Objective To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections. Methods A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise reduction (NR), NR+ scatter correction (SC), NR+ SC+ resolution recovery (RR)), NR+ SC+ RR+ attenuation correction (AC; total corrections, TC). Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality (R2) and fraction blood volume (FBV) to assess the quality of modeling. Rest MBF (RMBF), stress MBF (SMBF) and myocardial flow reserve (MFR) quantified from no correction (NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear regression analysis were used to analyze the data. Results Compared to TC, NC showed the lowest R2 (rest: 0.69, stress: 0.78; z values: 4.78 and 4.78, both P<0.01) and highest FBV (rest: 0.37, stress: 0.40; z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR (z values: 1.27 and -3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values: from -4.55 to 1.27, all P<0.01). NR and NR+ SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+ SC, NR+ SC+ RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1.129-1.308, and Bland-Altman plots demonstrated positive biases (0.60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70, -0.11, -0.05, 0.01). Conclusion Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pinhole CZR-SPECT. Key words: Coronary artery disease; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Tellurium; Zinc; Cadmium; Attenuation correction