AUTHOR=Yamaguchi Tomohiro , Ehara Shoichi , Yoshida Hisako , Himoto Daisuke , Izuta Shinichiro , Hayashi Ou , Hayashi Hiroya , Ogawa Mana , Shibata Atsushi , Yamazaki Takanori , Izumiya Yasuhiro , Fukuda Daiju TITLE=Quantification of pulmonary perfusion using LSIM-CT correlates with pulmonary hemodynamics in patients with CTEPD JOURNAL=Frontiers in Cardiovascular Medicine VOLUME=10 YEAR=2023 URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2023.1237296 DOI=10.3389/fcvm.2023.1237296 ISSN=2297-055X ABSTRACT=Background

Lung subtraction iodine mapping (LSIM)-CT is a clinically useful technique that can visualize pulmonary mal-perfusion in patients with chronic thromboembolic pulmonary disease (CTEPD). However, little is known about the associations of LSIM images with hemodynamic parameters of patients with CTEPD. This study investigates a parameter of LSIM images associated with mean pulmonary arterial pressure (mPAP) and validates the association between pulmonary vascular resistance, right atrial pressure, cardiac index, and exercise capacity in patients with CTEPD.

Methods

This single-center, prospective, observational study involved 30 patients diagnosed with CTEPD using lung perfusion scintigraphy. To examine the correlation of decreased pulmonary perfusion area (DPA) with mPAP, areas with 0–10, 0–15, 0–20, and 0–30 HU in lung subtraction images were adopted in statistical analysis. The DPA to total lung volume ratio (DPA ratio, %) was calculated as the ratio of each DPA volume to the total lung volume. To assess the correlation between DPA ratios of 0–10, 0–15, 0–20, and 0–30 HU and mPAP, Spearman's rank correlation coefficient was used.

Results

The DPA ratio of 0–10 HU had the most preferable correlation with mPAP than DPA ratios of 0–15, 0–20, and 0–30 HU (ρ = 0.440, P = 0.015). The DPA ratio of 0–10 HU significantly correlates with pulmonary vascular resistance (ρ = 0.445, P = 0.015). The receiver operating characteristic curve analysis indicated that the best cutoff value of the DPA ratio of 0–10 HU for the prediction of an mPAP of ≥30 mmHg was 8.5% (AUC, 0.773; 95% CI, 0.572–0.974; sensitivity, 83.3%; specificity, 75.0%). Multivariate linear regression analysis, which was adjusted for the main pulmonary arterial to ascending aortic diameter ratio and right ventricular to left ventricular diameter ratio, indicated that the DPA ratio of 0–10 HU was independently and significantly associated with mPAP (B = 89.7; 95% CI, 46.3–133.1, P < 0.001).

Conclusion

The DPA ratio calculated using LSIM-CT is possibly useful for estimating the hemodynamic status in patients with CTEPD.