From Stars to Stripes: Increasing Image Quality and Acquisition Speed in 4D Radiotherapy MR Imaging

Motivation: Respiratory motion complicates abdominal tumor delineation in radiotherapy, thereby impacting treatment accuracy. Conventional radial imaging may suffer from blurring and artifacts, compromising image quality. Accelerated advanced cartesian imaging may mitigate these issues and enable higher acceleration. Goal(s): To assess whether a cartesian compressed sensing (CS) sequence can provide fast, high-quality 4D imaging for improved organ delineation in RT. Approach: The study compared the cartesian CS-VIBE with the conventional radial StarVIBE sequence, using phantom and human data, to assess acquisition time and image clarity across breathing phases. Results: CS-VIBE provided 55% faster acquisition with sharper motion delineation, supporting its potential for clinical RT applications. Impact: This study shows that self-navigated cartesian imaging enables rapid, precise abdominal 4D motion capture in free breathing, potentially advancing radiotherapy planning. Its high-resolution imaging capacity may refine clinical protocols, supporting broader adoption of 4D imaging in radiotherapy planning.