Feasibility of Using Short Repetition Time for Brain Tumors in 23Na-MRI.

RATIONALE AND OBJECTIVES: 23Na‑MR imaging requires lengthy acquisition times, it remains difficult to implement routinely in clinical workflows and limits broader clinical application. This study aimed to determine whether a TR of 60 ms (TR60) could maintain brain tumor conspicuity while reducing acquisition time compared to TR100. MATERIALS AND METHODS: This prospective study includes adult patients with histopathologically confirmed supratentorial brain tumors. A 3 T scanner with a dual-tuned 1H/23Na birdcage head coil was used. A 3D radial stack-of-stars sequence was employed for the acquisition of 23Na-MR images. The lesion conspicuity on 23Na-MR images was evaluated using the contrast-to-noise ratio (CNR) and CNR efficiency (CNR/√ acquisition time; time-CNR), calculated by comparing the signal intensity of the tumor with that of the background. The CNR and time-CNR were then compared between TR60 and TR100 in detecting brain tumors. RESULTS: A total of 30 patients (22 men) were enrolled. No significant differences were observed in the CNR between TR60 and TR100 (p = 0.56). The time-CNR of TR60 was significantly higher than that of TR100 (p < 0.001). CONCLUSION: 23Na-MR imaging using TR60 achieved a significantly higher time-CNR than TR100 while maintaining comparable CNR, indicating improved acquisition efficiency for brain tumor evaluation.