The Feasibility of Half-Dose Contrast-Enhanced Scanning of Brain Tumours at 5.0 T: a preliminary study

Purpose: This study investigated the Gd-based enhanced effects on brain tumours with half-dose at 5.0 T and with full-dose at 3.0 T. Both quantitative and subjective evaluation parameters suggested that half-dose enhanced scanning at 5.0 T MRI might be feasible to meet the clinical diagnostic requirements. Methods: Twelve subjects diagnosed with brain tumours were included in this study, and scanned after contrast agent injection at 3.0 T (full-dose) and 5.0 T (half-dose) with a 3D T1-weighted gradient echo sequence, respectively. The post-contrast images were compared between 5.0 T and 3.0 T, in terms of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and subjective image quality score with a ten-point Likert scale. Comparing quantitative indices and subjective picture quality ratings with a paired Student's t-test and assessing inter-reader agreement with the intra-class correlation coefficient (ICC). Results: A total of 16 enhanced tumours lesions were detected. The SNR was significantly higher at 5.0 T than 3.0 T in gray matter, white matter and enhanced lesions (p < 0.001). The CNR was also significantly higher at 5.0 T than 3.0 T MRI in gray matter-tumor lesion, white matter-tumor lesion, and gray matter-white matter (p < 0.001). Subjective evaluation showed that the internal structure and outline of the tumor lesions were more clearly displayed with half-does at 5.0 T, and the enhanced effects of the lesions was comparable to that with full-dose at 3.0 T. All subjective scores were good to excellent at both 5.0 T and 3.0 T. Conclusion: 5.0 T half-dose intravenous contrast agents enhanced scanning might be feasible to meet the clinical diagnostic requirements of brain tumours.