Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Old Road Campus Research Building, Headington, Oxford, OX3 7DQ, UK.
Perspectum Ltd, Oxford, UK.
Abdom Radiol (NY). 2023 Mar;48(3):865-873. doi: 10.1007/s00261-022-03762-4. Epub 2022 Dec 15.
R2*, a measurement obtained using magnetic resonance imaging (MRI) can be used to estimate liver iron concentration (LIC). 3 T and 1.5 T scanners can be used but conversion of 3 T R2* to LIC is less well validated. In this study the aim was to compare 3 T-R2* LIC and 1.5 T-R2* LIC estimations to assess if they can be used interchangeably.
Thirty participants were scanned at both 1.5 T and 3 T. R2* was measured at both field strengths. 3 T R2* and 1.5 R2* were compared using linear regression and were converted to LIC using different calibration curves. Pearson's rho and Intraclass Correlation Coefficients (ICCs) were used to assess correlation and agreement between 1.5 and 3 T LIC. Bland Altman plots were used to assess bias and limits of agreement.
All 1.5 T and 3 T LIC comparisons gave Pearson's rho of 0.99 (p < 0.001). ICC ranged from 0.83 (p = 0.005) to 0.96 (p < 0.001). Biases had magnitude of less than 0.2 mg/g dry weight.
Agreement and bias between 3 and 1.5 T-R2* LIC depended on the method used for conversion. There were instances when the agreement was excellent and bias was small, indicating that potentially 3 T-R2* LIC can be used alongside or instead of 1.5 T-R2* LIC but care needs to be taken over the conversion methods selected.
Clinicaltrials.gov NCT03743272, 16 November 2018.
使用磁共振成像（MRI）获得的 R2* 可用于估计肝铁浓度（LIC）。可以使用 3T 和 1.5T 扫描仪，但 3T R2* 到 LIC 的转换尚未得到充分验证。本研究旨在比较 3T-R2* LIC 和 1.5T-R2* LIC 的估计值，以评估它们是否可以互换使用。
30 名参与者在 1.5T 和 3T 下进行扫描。在两种场强下测量 R2*。使用线性回归比较 3T R2* 和 1.5R2*，并使用不同的校准曲线将其转换为 LIC。使用 Pearson 相关系数和组内相关系数（ICC）评估 1.5T 和 3T LIC 之间的相关性和一致性。Bland-Altman 图用于评估偏差和一致性界限。
所有 1.5T 和 3T LIC 比较的 Pearson 相关系数均为 0.99（p<0.001）。ICC 范围为 0.83（p=0.005）至 0.96（p<0.001）。偏差的幅度小于 0.2mg/g 干重。
3T 和 1.5T-R2* LIC 之间的一致性和偏差取决于转换方法的选择。在某些情况下，一致性非常好，偏差很小，表明 3T-R2* LIC 可能可以与 1.5T-R2* LIC 一起使用或替代 1.5T-R2* LIC，但需要注意所选的转换方法。
Clinicaltrials.gov NCT03743272，2018 年 11 月 16 日。
