Wood John C, Ghugre Nilesh
Children's Hospital of Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, California 90027, USA.
Hemoglobin. 2008;32(1-2):85-96. doi: 10.1080/03630260701699912.
Patients with transfusion-dependent anemia develop cardiac and endocrine toxicity from iron overload. Classically, serum ferritin and liver biopsy have been used to monitor patient response to chelation therapy. Recently, magnetic resonance imaging (MRI) has proven effective in detecting and quantifying iron in the heart and liver. Tissue iron is paramagnetic and increases the MRI relaxation rates R2 and R2* in a quantifiable manner. This review outlines the principles and validation of non invasive iron estimation by MRI, as well as discussing some of the technical considerations necessary for accurate measurements. Specifically, the use of R2 or R2* methods, choice of echo times, appropriate model for data fitting, the use of a pixel-wise or region-based measurement, and the choice of field strength are discussed.
依赖输血的贫血患者会因铁过载而出现心脏和内分泌毒性。传统上，血清铁蛋白和肝脏活检一直用于监测患者对螯合疗法的反应。最近，磁共振成像（MRI）已被证明在检测和量化心脏和肝脏中的铁方面有效。组织铁具有顺磁性，并以可量化的方式增加MRI弛豫率R2和R2*。本综述概述了通过MRI进行无创铁估计的原理和验证，并讨论了准确测量所需的一些技术考虑因素。具体讨论了R2或R2*方法的使用、回波时间的选择、数据拟合的适当模型、逐像素或基于区域的测量的使用以及场强的选择。
