Room Temp Susceptometry For Hepatic Iron Measurement

铁过载可能在许多不同的器官中发展，导致显著的发病率和死亡率。通过静脉切开术或螯合疗法来消耗铁可以动员体内多余的铁储存并改善结果。因此，铁超载的检测和定量具有重要的临床意义。肝脏是体内铁的主要储存部位，肝脏铁负荷的程度被认为反映了体内铁的储存。目前，肝铁浓度（HIC）的生化测定被认为是临床评估铁超载的最敏感方法。然而，这种方法具有显著的局限性，因为需要侵入性肝活检程序和由于HIC的肝内变异性而导致的采样误差。 针吸肝活检测量的这些局限性使得有必要开发替代的、非侵入性的和更可靠的HIC测量方法。这项研究将评估一种新的，低成本的，便携式设备，用于非侵入性测量肝脏中的铁浓度。这种新仪器是一种基于简单的室温磁传感器的磁力计。在以前的测试中，来自新的铁浓度计的肝脏铁值与现有的基于液氦冷却的超导传感器的“SQUID”铁浓度计的值具有良好的相关性（r=0.98），尽管没有与来自组织样本的生化铁浓度进行直接比较。这项横断面队列研究的目的是通过研究与遗传性血色素沉着症、丙型肝炎感染或非酒精性脂肪性肝炎相关的铁过载患者，验证室温血糖仪作为临床工具的有效性。将肝活检标本的生化铁测量值与从同一肝叶获得的测铁计值进行比较。这些患者人群将测试室温磁共振仪在测量具有广泛HIC和由于纤维化和肝硬化程度导致的铁分布变异性的患者中的肝铁方面的效用。

Iron overload may develop in a number of different organs, leading to significant morbidity and mortality. Iron depletion by phlebotomy or chelation can mobilize excess body iron stores and improve outcomes. Therefore, detection and quantitation of iron overload is of vital clinical importance. The liver is the primary storage site for iron in the body and the degree of hepatic iron loading is thought to reflect body iron stores. At present, biochemical measurement of hepatic iron concentration (HIC) is considered the most sensitive method for clinical assessment of iron overload. However, this method has significant limitations because of the need for an invasive liver biopsy procedure and sampling error due to intra-hepatic variability in HIC. These limitations of needle liver biopsy measurements have necessitated the development of alternative, non-invasive and more reliable methods for HIC measurement. This study will assess a new, low-cost, portable device for noninvasively measuring iron concentrations in the liver. The new instrument, is a magnetic susceptometer based on simple, room-temperature magnetic sensors. In previous tests, liver iron values from the new susceptometer correlated well (r=0.98) with those from an existing "SQUID" susceptometer based on superconducting sensors cooled by liquid helium, although there was no direct comparison with biochemical iron concentrations from tissue samples. The goal of this cross-sectional, cohort study, is to validate the room temperature susceptometer as a clinical tool, by studying patients with iron overload associated with hereditary hemochromatosis, hepatitis C infection or nonalcoholic steatohepatitis. Biochemical iron measurements from a liver biopsy specimen will be compared to the suseptometer values obtained from the same lobe of the liver. These patient populations will test the utility of the room temperature susceptometer in measuring liver iron in patients with a wide range of HIC and variability of iron distribution due to degree of fibrosis and cirrhosis.