Henninger B, Zoller H, Rauch S, Finkenstedt A, Schocke M, Jaschke W, Kremser C
Radiology, Medical University of Innsbruck, Austria.
Internal Medicine, Medical University of Innsbruck, Austria.
Rofo. 2015 Jun;187(6):472-9. doi: 10.1055/s-0034-1399318. Epub 2015 Apr 15.
We compared the calibration of hepatic iron based on R2* relaxometry and liver biopsy with similar studies that have already been published to investigate the transferability of published calibration curves.
17 patients with clinically suspected hepatic iron overload (HIO) were enrolled. All patients underwent liver biopsy and MRI of the liver using a multi-echo gradient echo sequence (TR = 200 ms; TE-initial 0.99 ms; Delta-TE 1.41 ms; 12 echos; flip-angle: 20 °). R2* parameter maps were analyzed using manually placed regions of interest and R2* values were correlated with liver iron concentration (LIC) obtained from liver biopsy. In addition, the results of our study were compared with 6 similar, already published studies.
A linear relationship between R2* and LIC was found. Regression analysis yielded a correlation coefficient of 0.926, a slope of 0.024 (s mg/g) [95 % CI 0.013 - 0.024] and an intercept of 0.277 (mg/g) [95 % CI -0.328 - 2.49]. We found a significant correlation between the calibration curves obtained from our study in comparison to 3/6 similar studies. The other 3 studies used a different reference standard or sequence parameters which lead to a significant difference for slope, intercept or both in comparison to our data.
Calibration curves from published studies that are based on a correlation of liver biopsy and R2* can be used for the estimation of liver iron concentration, although different scanning parameters and post-processing protocols were used. Low initial TEs might be a prerequisite for pooling data for liver iron quantification.
• Calibration curves from different studies can be used for liver iron quantification• For that purpose calibration curves from published studies should be based on liver biopsy• Low initial TEs might be a prerequisite for pooling data for liver iron quantification.
我们将基于R2*弛豫测量法和肝活检的肝脏铁校准与已发表的类似研究进行比较，以研究已发表校准曲线的可转移性。
纳入17例临床怀疑肝铁过载（HIO）的患者。所有患者均接受了肝活检和肝脏MRI检查，采用多回波梯度回波序列（TR = 200 ms；初始TE 0.99 ms；ΔTE 1.41 ms；12个回波；翻转角：20°）。使用手动放置的感兴趣区域分析R2参数图，并将R2值与肝活检获得的肝铁浓度（LIC）进行关联。此外，将我们的研究结果与6项类似的已发表研究进行了比较。
发现R2*与LIC之间存在线性关系。回归分析得出相关系数为0.926，斜率为0.024（s mg/g）[95%CI 0.013 - 0.024]，截距为0.277（mg/g）[95%CI -0.328 - 2.49]。与3/6项类似研究相比，我们研究获得的校准曲线之间存在显著相关性。其他3项研究使用了不同的参考标准或序列参数，导致与我们的数据相比，斜率、截距或两者均存在显著差异。
尽管使用了不同的扫描参数和后处理方案，但基于肝活检与R2*相关性的已发表研究的校准曲线可用于估计肝铁浓度。低初始TE可能是合并肝铁定量数据的先决条件。
• 不同研究的校准曲线可用于肝铁定量 • 为此，已发表研究的校准曲线应基于肝活检 • 低初始TE可能是合并肝铁定量数据的先决条件。
