Improved abdominal MRI in non-breath-holding children using a radial k-space sampling technique

Background: Radial k-space sampling techniques have been shown to reduce motion artifacts in adult abdominal MRI.

Objective: To compare a T2-weighted radial k-space sampling MRI pulse sequence (BLADE) with standard respiratory-triggered T2-weighted turbo spin echo (TSE) in pediatric abdominal imaging. Materials and methods: Axial BLADE and respiratory-triggered turbo spin echo sequences were performed without fat suppression in 32 abdominal MR examinations in children. We retrospectively assessed overall image quality, the presence of respiratory, peristaltic and radial artifact, and lesion conspicuity. We evaluated signal uniformity of each sequence. Results: BLADE showed improved overall image quality (3.35 ± 0.85 vs. 2.59 ± 0.59, P < 0.001), reduced respiratory motion artifact (0.51 ± 0.56 vs. 1.89 ± 0.68, P < 0.001), and improved lesion conspicuity (3.54 ± 0.88 vs. 2.92 ± 0.77, P = 0.006) compared to respiratory triggering turbo spin-echo (TSE) sequences. The bowel motion artifact scores were similar for both sequences (1.65 ± 0.77 vs. 1.79 ± 0.74, P = 0.691). BLADE introduced a radial artifact that was not observed on the respiratory triggering-TSE images (1.10 ± 0.85 vs. 0, P < 0.001). BLADE was associated with diminished signal variation compared with respiratory triggering-TSE in the liver, spleen and air (P < 0.001). Conclusion: The radial k-space sampling technique improved the quality and reduced respiratory motion artifacts in young children compared with conventional respiratory-triggered turbo spin-echo sequences.