Purpose: The purpose of this study was to assess the feasibility of color K-edge imaging enabled by spectral photon-counting CT (SPCCT) for simultaneous ventilation-perfusion evaluation using xenon and a gadolinium-based agent within healthy rabbit lungs. Materials and methods: In this animal study, a clinical SPCCT prototype was used to perform lung imaging in five New Zealand white rabbits. A phantom study was performed to assess gadolinium quantification accuracy and cross-contamination. Animals underwent controlled mechanical ventilation with xenon gas wash-in and received an intravenous injection of a gadolinium-based ultrasmall rigid platform (USRP) (dose, 2.3 mL·kg-1; injection rate, 3 mL·s-1; concentration, 0.29 mmol Gd.mL-1). Material decomposition yielded specific xenon and gadolinium K-edge images. Xenon maps were validated against dynamic specific ventilation maps using Pearson correlation test and linear regression analysis. Regional lung distribution was analyzed using Kruskal-Wallis test. Results: Five rabbits (mean weight, 2.9 ± 0.06 [standard deviation] kg) were evaluated. In phantoms, measured gadolinium concentrations showed a perfect linear correlation with prepared concentrations (R2 = 1). In vivo, normalized steady-state xenon maps demonstrated a strong correlation with specific ventilation maps, with a pooled Pearson correlation coefficient of 0.88 and a pooled R2 of 0.78. Simultaneous imaging revealed a homogeneous xenon distribution with a median value across rabbits of 60.2% (first quartile [Q1], 59.3%; third quartile [Q3], 67.9%), with no significant regional differences. The median gadolinium perfusion across rabbits was 6.1% (Q1, 3.0%; Q3, 7.1%), with a significant dorsal-ventral gradient (P < 0.05) where the median value increased from 0.2% (Q1, -0.2%; Q3, 1.3%) in ventral regions to 6.9% (Q1, 3.8%; Q3, 10.6%) in dorsal regions. Conclusion: Color K-edge xenon/gadolinium-enhanced lung imaging using SPCCT is feasible in healthy animals, enabling the simultaneous specific and quantitative imaging of lung gas and blood volume.
Simultaneous pulmonary ventilation and perfusion imaging using spectral photon counting CT with xenon and gadolinium-based agents in combination with color K-edge imaging
Poletto, Sofia;Dellaca', Raffaele;
2026-01-01
Abstract
Purpose: The purpose of this study was to assess the feasibility of color K-edge imaging enabled by spectral photon-counting CT (SPCCT) for simultaneous ventilation-perfusion evaluation using xenon and a gadolinium-based agent within healthy rabbit lungs. Materials and methods: In this animal study, a clinical SPCCT prototype was used to perform lung imaging in five New Zealand white rabbits. A phantom study was performed to assess gadolinium quantification accuracy and cross-contamination. Animals underwent controlled mechanical ventilation with xenon gas wash-in and received an intravenous injection of a gadolinium-based ultrasmall rigid platform (USRP) (dose, 2.3 mL·kg-1; injection rate, 3 mL·s-1; concentration, 0.29 mmol Gd.mL-1). Material decomposition yielded specific xenon and gadolinium K-edge images. Xenon maps were validated against dynamic specific ventilation maps using Pearson correlation test and linear regression analysis. Regional lung distribution was analyzed using Kruskal-Wallis test. Results: Five rabbits (mean weight, 2.9 ± 0.06 [standard deviation] kg) were evaluated. In phantoms, measured gadolinium concentrations showed a perfect linear correlation with prepared concentrations (R2 = 1). In vivo, normalized steady-state xenon maps demonstrated a strong correlation with specific ventilation maps, with a pooled Pearson correlation coefficient of 0.88 and a pooled R2 of 0.78. Simultaneous imaging revealed a homogeneous xenon distribution with a median value across rabbits of 60.2% (first quartile [Q1], 59.3%; third quartile [Q3], 67.9%), with no significant regional differences. The median gadolinium perfusion across rabbits was 6.1% (Q1, 3.0%; Q3, 7.1%), with a significant dorsal-ventral gradient (P < 0.05) where the median value increased from 0.2% (Q1, -0.2%; Q3, 1.3%) in ventral regions to 6.9% (Q1, 3.8%; Q3, 10.6%) in dorsal regions. Conclusion: Color K-edge xenon/gadolinium-enhanced lung imaging using SPCCT is feasible in healthy animals, enabling the simultaneous specific and quantitative imaging of lung gas and blood volume.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
