Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, China.
Medical Imaging Department, Shenzhen Ban'an Traditional Chinese Medicine Hospital Group, Shenzhen, China.
BMC Med Imaging. 2024 Apr 13;24(1):88. doi: 10.1186/s12880-024-01270-z.
This study investigated and compared the effects of Gd enhancement on brain tumours with a half-dose of contrast medium at 5.0 T and with a full dose at 3.0 T.
Twelve subjects diagnosed with brain tumours were included in this study and underwent MRI after contrast agent injection at 3.0 T (full dose) or 5.0 T (half dose) with a 3D T1-weighted gradient echo sequence. The postcontrast images were compared by two independent neuroradiologists in terms of the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and subjective image quality score on a ten-point Likert scale. Quantitative indices and subjective quality ratings were compared with paired Student's t tests, and interreader agreement was assessed with the intraclass correlation coefficient (ICC).
A total of 16 enhanced tumour lesions were detected. The SNR was significantly greater at 5.0 T than at 3.0 T in grey matter, white matter and enhanced lesions (p < 0.001). The CNR was also significantly greater at 5.0 T than at 3.0 T for grey matter/tumour lesions, white matter/tumour lesions, and grey matter/white matter (p < 0.001). Subjective evaluation revealed that the internal structure and outline of the tumour lesions were more clearly displayed with a half-dose at 5.0 T (Likert scale 8.1 ± 0.3 at 3.0 T, 8.9 ± 0.3 at 5.0 T, p < 0.001), and the effects of enhancement in the lesions were comparable to those with a full dose at 3.0 T (7.8 ± 0.3 at 3.0 T, 8.7 ± 0.4 at 5.0 T, p < 0.001). All subjective scores were good to excellent at both 5.0 T and 3.0 T.
Both quantitative and subjective evaluation parameters suggested that half-dose enhanced scanning via 5.0 T MRI might be feasible for meeting clinical diagnostic requirements, as the image quality remains optimal. Enhanced scanning at 5.0 T with a half-dose of contrast agents might benefit patients with conditions that require less intravenous contrast agent, such as renal dysfunction.
本研究旨在对比分析 5.0T 磁共振成像（MRI）半剂量钆对比剂增强扫描与 3.0T 磁共振成像全剂量钆对比剂增强扫描对脑肿瘤的影响。
本研究纳入 12 例脑肿瘤患者，分别在 3.0T（全剂量）和 5.0T（半剂量）磁共振扫描仪上进行对比剂增强后 3D T1 加权梯度回波序列扫描。由 2 位独立的神经放射科医生采用 10 分制 Likert 量表对图像的信噪比（SNR）、对比噪声比（CNR）和主观图像质量评分进行评估。采用配对 Student's t 检验比较定量指标和主观质量评分，采用组内相关系数（ICC）评估观察者间的一致性。
共检出 16 个增强病灶。与 3.0T 相比，5.0T 时脑灰质、脑白质和增强病灶的 SNR 显著增高（均 P<0.001）。5.0T 时脑灰质/肿瘤、脑白质/肿瘤和脑灰质/脑白质的 CNR 也显著高于 3.0T（均 P<0.001）。主观评价显示，5.0T 半剂量时肿瘤内部结构和轮廓显示更清晰（3.0T 评分为 8.1±0.3，5.0T 评分为 8.9±0.3，P<0.001），病灶增强效果与 3.0T 全剂量相当（3.0T 评分为 7.8±0.3，5.0T 评分为 8.7±0.4，P<0.001）。两种扫描方法的主观评分均为 7 分及以上（非常好到极好）。
定量和主观评价参数均表明，5.0T 磁共振成像半剂量增强扫描可能满足临床诊断要求，且图像质量仍保持最优。肾功能不全等需要较少静脉内对比剂的患者，可考虑采用 5.0T 磁共振成像半剂量增强扫描。
