Motion and anatomy dual aware lung ventilation imaging by integrating Jacobian map and average CT image using dual...

Deep learning-based computed tomography (CT) ventilation imaging (CTVI) is a promising technique for guiding functional lung avoidance radiotherapy (FLART). However, conventional approaches, which rely on anatomical CT data, may overlook important ventilation features due to the lack of motion data integration.

This study aims to develop a novel dual-aware CTVI method that integrates both anatomical information from CT images and motional information from Jacobian maps to generate more accurate ventilation images for FLART.

A dataset of 66 patients with four-dimensional CT (4DCT) images and reference ventilation images (RefVI) was utilized to develop the dual-path fusion network (DPFN) for synthesizing ventilation images (CTVI_Dual). The DPFN model was specifically designed to integrate motion data from 4DCT-generated Jacobian maps with anatomical data from average 4DCT images. The DPFN utilized two specialized feature extraction pathways, along with encoders and decoders, designed to handle both 3D average CT images and Jacobian map data. This dual-processing approach enabled the comprehensive extraction of lung ventilation-related features. The performance of DPFN was assessed by comparing CTVI_Dual to RefVI using various metrics, including Spearman's correlation coefficients (R), Dice similarity coefficients of high-functional region (DSC_h), and low-functional region (DSC_l). Additionally, CTVI_Dual was benchmarked against other CTVI methods, including a dual-phase CT-based deep learning method (CTVI_DLCT), a radiomics-based method (CTVI_FM), a super voxel-based method (CTVI_SVD), a Unet-based method (CTVI_Unet), and two deformable registration-based methods (CTVI_Jac and CTVI_HU).

In the test group, the mean R between CTVI_Dual and RefVI was 0.70, significantly outperforming CTVI_DLCT (0.68), CTVI_FM (0.58), CTVI_SVD (0.62), and CTVI_Unet (0.66), with p < 0.05. Furthermore, the DSC_h and DSC_l values of CTVI_Dual were 0.64 and 0.80, respectively, outperforming CTVI_SVD (0.63; 0.73) and CTVI_Unet (0.62; 0.77). The performance of CTVI_Dual was also significantly better than that of CTVI_Jac and CTVI_HU.

A novel dual-aware CTVI model that integrates anatomical and motion information was developed to synthesize lung ventilation images. It was shown that the accuracy of lung ventilation estimation could be significantly enhanced by incorporating motional information, particularly in patients with tumor-induced blockages. This approach has the potential to improve the accuracy of CTVI, enabling more effective FLART.