Anorectal Angle Is Associated With Bowel Toxicity One Month Following Radiation Therapy for Prostate Cancer

compared to the true T2-w ‘4D-MRI’ of the phantom. Results: In phantom study, pseudo T2-w ‘4D-MRI’matched well with true T2-w ‘4D-MRI’, with only minimal differences between the two that were potentially due to residual errors in DIR. Pseudo T2-w 4D-MRI improved tumor-to-tissue CNR (32.2 ± 5.9) as compared to those of original T2*/T1w 4D-MRI (16.1 ± 2.0), while both showed superior CNR over 4D-CT (1.4 ± 1.2). PseudoT2-w4D-MRI revealed similarmotion patterns of organs and tumor as observed in T2*/T1-w 4D-MRI. Conclusions: Improvement in tumor-to-tissue CNR of 4D-MRI by combining T2-w MRI and DIR is feasible. Further validation of the proposed method is required.