Schoennagel Bjoern P, Remus Chressen C, Wedegaertner Ulrike, Salzmann Ina, Grabhorn Enke, Adam Gerhard, Fischer Roland, Harmatz Paul, Kooijman Hendrik, Yamamura Jin
Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf.
Magn Reson Med Sci. 2014;13(3):167-73. doi: 10.2463/mrms.2013-0096. Epub 2014 Jul 2.
We evaluated the feasibility of prenatal quantification of liver and spleen iron by magnetic resonance imaging (MRI) gradient recalled echo (GRE) measurements of transverse relaxation time (R2*) (MRI-GRE-R2*) in a fetal sheep model and applied the method to a human neonate with suspected neonatal hemochromatosis.
We subjected 13 fetal sheep to MRI at 1.5 Tesla using a breath-triggered (ewe) multi-echo sequence to determine the transverse relaxation rate (R2*) of the liver and spleen. In the human neonate, we measured the R2* of the liver, spleen, and pancreas on the 30th postgestational day.
The median R2* of the fetal sheep liver was 25.6 s(-1) (range 20 to 114 s(-1)) and of the spleen, 40.2 s(-1) (range 20 to 70 s(-1)), and the corresponding median iron concentration in the liver was 0.85 mg/g dry weight (d.w.) and in the spleen, 1.22 mg/gd.w.. R2* rates in the human neonate liver were elevated between 67 s(-1) (average), which corresponded with an iron concentration of 1.9 mg Fe/gd.w., and 126 s(-1) (regional maximum), which corresponded with 3.4 mg Fe/gd.w.. The average pancreatic R2* (72.4 s(-1)) was significantly above normal values, which indicated iron overload.
We demonstrated the feasibility of prenatal quantification of tissue iron by fetal MRI in this sheep model and successfully quantified iron, including that in the pancreas, in a human neonate to confirm the diagnosis of neonatal hemochromatosis. Transferring the successful approach of quantifying iron in intrauterine tissue in fetal sheep to human pregnancies with suspected fetal siderosis could aid early diagnosis.
我们在胎羊模型中通过磁共振成像（MRI）梯度回波（GRE）测量横向弛豫时间（R2*）（MRI-GRE-R2*）评估产前定量肝脏和脾脏铁含量的可行性，并将该方法应用于一名疑似新生儿血色病的人类新生儿。
我们使用呼吸触发（母羊）多回波序列，在1.5特斯拉对13只胎羊进行MRI检查，以确定肝脏和脾脏的横向弛豫率（R2*）。在人类新生儿中，我们在出生后第30天测量了肝脏、脾脏和胰腺的R2*。
胎羊肝脏的R2中位数为25.6 s⁻¹（范围20至114 s⁻¹），脾脏为40.2 s⁻¹（范围20至70 s⁻¹），肝脏中相应的铁浓度中位数为0.85 mg/g干重（d.w.），脾脏为1.22 mg/g d.w.。人类新生儿肝脏的R2率升高，平均为67 s⁻¹，对应铁浓度为1.9 mg Fe/g d.w.，区域最大值为126 s⁻¹，对应3.4 mg Fe/g d.w.。胰腺的平均R2*（72.4 s⁻¹）显著高于正常值，表明铁过载。
我们在该羊模型中证明了通过胎儿MRI产前定量组织铁含量的可行性，并成功定量了一名人类新生儿的铁含量，包括胰腺中的铁含量，以确诊新生儿血色病。将在胎羊子宫内组织中定量铁的成功方法应用于疑似胎儿铁沉积症的人类妊娠，有助于早期诊断。
