Quantitative Dual-Energy CT Perfusion Versus SPECT/CT V/Q Scintigraphy for Preoperative Lung Function Assessment: A Prospective Cohort Study

Abstract

Accurate preoperative physiological assessment is critical for high-risk patients undergoing lung resection to predict postoperative lung function. This study compared quantitative dual-energy CT (DECT) perfusion with SPECT/CT for lobar perfusion mapping in an at-risk oncological cohort. In a prospective, single-centre study, 20 high-risk candidates for lung resection (FEV1 or DLCO < 80% predicted) underwent both contrast-enhanced DECT and SPECT/CT V/Q. Perfusion was quantified for all 100 lung lobes. Agreement between modalities was assessed using Pearson's correlation coefficient (r), Intraclass Correlation Coefficient (ICC), and Bland-Altman analysis. Effective radiation doses were calculated and compared for both protocols. DECT perfusion measurements demonstrated a strong correlation with SPECT/CT (Pearson's r = 0.94, p < 0.001; ICC = 0.93). Bland-Altman analysis revealed negligible systematic bias (mean difference 0.03%) with narrow limits of agreement, although a minor proportional bias was observed where DECT slightly overestimated perfusion in low-function lobes. Furthermore, the DECT protocol resulted in a statistically significant reduction in mean effective radiation dose compared to SPECT/CT (4.42 mSv vs. 4.87 mSv; p = 0.026). In this pilot study, DECT perfusion imaging demonstrated lobar function quantification closely concordant with SPECT/CT V/Q in high-risk surgical candidates. With the potential for superior spatial resolution, reduced radiation exposure, and 'one-stop' efficiency, DECT shows promise as a resource-efficient alternative for preoperative planning, warranting further validation in larger cohorts.