Gotsis Efstathios D
Institute Euromedica-Encephalos, Athens, Greece.
Hemoglobin. 2008;32(1-2):75-83. doi: 10.1080/03630260701726293.
Early attempts to use magnetic resonance imaging (MRI) for assessing iron overload in beta-thalassemia (thal) patients began more than 20 years ago. With advances in MRI, more quantitative efforts focused on measuring transverse relaxation time rates (R2 and R2*) of the liver and/or myocardium. Recently, calibration curves of R2 and R2* were reported that allowed one to determine the absolute concentrations of iron in the liver, provided that R2 and R2* were determined with the same technique. The difficulty of obtaining sufficient myocardium biopsy samples has prevented similar calibration curves being reported for the myocardium. Preliminary data indicate that liver and myocardium R2* vs. R2 plots are similar over a large range of R2* and R2 values. Obviously, myocardium biopsy samples are needed to confirm whether myocardium R2* and R2 plots vs. iron concentration are similar to those published for the liver. The various methods for determining R2 and R2* are discussed. It is suggested to use both R2* and R2 for assessing iron overload in the liver and myocardium.
20多年前就开始了早期利用磁共振成像（MRI）评估β地中海贫血（β-地贫）患者铁过载的尝试。随着MRI技术的进步，更多定量研究致力于测量肝脏和/或心肌的横向弛豫时间率（R2和R2*）。最近，有报道称R2和R2的校准曲线可用于确定肝脏中铁的绝对浓度，前提是R2和R2是用相同技术测定的。获取足够心肌活检样本的困难使得心肌的类似校准曲线尚未见报道。初步数据表明，在较大范围的R2和R2值内，肝脏和心肌的R2与R2图相似。显然，需要心肌活检样本以确认心肌的R2和R2图与铁浓度的关系是否与已发表的肝脏情况相似。文中讨论了测定R2和R2的各种方法。建议同时使用R2*和R2来评估肝脏和心肌的铁过载情况。
