Hou Ping, Popat Uday R, Lindsay Richard J, Jackson Edward F, Choi Haesun
Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
Radiol Res Pract. 2012;2012:207391. doi: 10.1155/2012/207391. Epub 2012 Dec 11.
The goal of this study is to demonstrate a practical magnetic resonance imaging technique for quantifying a wide range of hepatic iron concentration (HIC) for hematologic oncology patients with transfusion iron overload in a routine clinical setting. To cover a wide range of T(2)* values from hematologic patients, we used a dual-acquisition method with two clinically available acquisition protocols on a 1.5T MRI scanner with different ΔTEs to acquire data in two breath-holds. An in-house image postprocessing software tool was developed to generate T(2), iron maps, and water and fat images, when fat is presented in the liver. The resulting iron maps in DICOM format are transferred to the institutional electronic medical record system for review by radiologists. The measured liver T(2) values for 28 patients ranged from 0.56 ± 0.13 to 25.0 ± 2.1 milliseconds. These T(2)* values corresponded to HIC values ranging from 1.2 ± 0.1 mg/g to 45.0 ± 10.0 mg/g (dry weight). A moderate correlation between overall serum ferritin levels and R(2)* was found with a correlation coefficient of 0.83. Repeated phantom scans confirmed that the precision of this method is better than 4% for T(2)* measurements. The dual- acquisition method also improved the ability to quantify HIC of the patients with hepatic steatosis.
本研究的目的是展示一种实用的磁共振成像技术,用于在常规临床环境中对输血性铁过载的血液肿瘤患者的广泛肝铁浓度(HIC)进行量化。为了涵盖血液学患者的广泛T(2)值范围,我们在一台1.5T MRI扫描仪上使用了双采集方法,采用两种临床可用的采集协议,通过不同的ΔTE在两次屏气中采集数据。开发了一个内部图像后处理软件工具,用于生成T(2)、铁图以及肝脏存在脂肪时的水和脂肪图像。以DICOM格式生成的铁图被传输到机构电子病历系统,供放射科医生查看。28例患者测得的肝脏T(2)*值范围为0.56±0.13至25.0±2.1毫秒。这些T(2)*值对应的HIC值范围为1.2±0.1mg/g至45.0±10.0mg/g(干重)。发现总体血清铁蛋白水平与R(2)*之间存在中度相关性,相关系数为0.83。重复的体模扫描证实,该方法对T(2)*测量的精度优于4%。双采集方法还提高了对肝脂肪变性患者HIC进行量化的能力。