A super‐resolution framework for the reconstruction of T2‐weighted (T2w) time‐resolved (TR) 4DMRI using T1w TR‐4DMRI as the guidance

作者：Xingyu Nie, Ziad Saleh, Mo Kadbi, Kristen L. Zakian, Joseph O. Deasy, Andreas Rimner, Guang Li · 发表于：Medical Physics · 年份：2020 · DOI：10.1002/mp.14136 · 被引用次数：14 · 研究领域：Advanced Radiotherapy Techniques、Lung Cancer Diagnosis and Treatment、Effects of Radiation Exposure

Purpose The purpose of this study was to develop T2‐weighted (T2w) time‐resolved (TR) four‐dimensional magnetic resonance imaging (4DMRI) reconstruction technique with higher soft‐tissue contrast for multiple breathing cycle motion assessment by building a super‐resolution (SR) framework using the T1w TR‐4DMRI reconstruction as guidance. Methods The multi‐breath T1w TR‐4DMRI was reconstructed by deforming a high‐resolution (HR: 2 × 2 × 2 mm 3 ) volumetric breath‐hold (BH, 20s) three‐dimensional magnetic resonance imaging (3DMRI) image to a series of low‐resolution (LR: 5 × 5 × 5 mm 3 ) 3D cine images at a 2Hz frame rate in free‐breathing (FB, 40 s) using an enhanced Demons algorithm, namely [T1 BH →FB] reconstruction. Within the same imaging session, respiratory‐correlated (RC) T2w 4DMRI (2 × 2 × 2 mm 3 ) was acquired based on an internal navigator to gain HR T2w (T2 HR ) in three states (full exhalation and mid and full inhalation) in ~5 min. Minor binning artifacts in the RC‐4DMRI were automatically identified based on voxel intensity correlation (VIC) between consecutive slices as outliers (VIC < VIC mean ‐σ) and corrected by deforming the artifact slices to interpolated slices from the adjacent slices iteratively until no outliers were identified. A T2 HR image with minimal deformation (<1 cm at the diaphragm) from the T1 BH image was selected for multi‐modal B‐Spline deformable image registration (DIR) to establish the T2 HR ‐T1 BH voxel correspondence. Two approac...