University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
J Magn Reson Imaging. 2010 Nov;32(5):1104-9. doi: 10.1002/jmri.22364.
To assess regional iron distribution by magnetic resonance imaging (MRI)-R(2)* within the heart of patients with β-thalassemia major (TM) and other iron overload diseases.
Breathhold electrocardiogram (ECG)-gated MRI (1.5 T) of the heart was used for the measurement of transverse relaxation rates R(2)* in 32 patients (11-79 years). In a mid-papillary short-axis slice divided into septal, anterior, lateral, and posterior quadrants, R(2)* was analyzed from region of interest (ROI)-based signal intensities from 12 echo times (TE = 1.3-26 msec). Typical boundary effects were evaluated in detail.
The segmentation of the cardiac wall resulted in highly significant correlations of R(2)* between septal and all other quadrants. In the patient group with R(2)* < 50 s(-1) (normal), all quadrants show higher normalized median rates (126%-174%) than the septum (P < 10(-4)), while this was relatively smaller in the group with septal R(2)* > 50 s(-1). Typical boundary effects on segmental R(2)* from blood, lung tissue, epicardial fat, and hepatic iron could not be easily separated from segmental iron distribution.
The measurement of MRI-R2* in the interventricular septum is the least affected method by boundary effects to detect patients with iron overload at risk of developing heart failure.
通过心脏磁共振成像（MRI）-R(2)*评估β-地中海贫血（TM）和其他铁过载疾病患者心脏内的区域铁分布。
使用心脏屏气心电图（ECG）门控 1.5 T MRI 测量 32 例患者（11-79 岁）的横向弛豫率 R(2)*。在心尖短轴中部切片中，将 R(2)*分为间隔、前、侧和后四个象限，在 12 个回波时间（TE = 1.3-26 msec）的基于感兴趣区（ROI）的信号强度进行分析。详细评估了典型的边界效应。
心脏壁的分割导致 R(2)在间隔和所有其他象限之间具有高度显著的相关性。在 R(2)<50 s(-1)（正常）的患者组中，所有象限的归一化中位数率（126%-174%）均高于间隔（P<10(-4)），而在间隔 R(2)*>50 s(-1)的患者组中，这种情况相对较小。来自血液、肺组织、心外膜脂肪和肝脏铁的节段性 R(2)*的典型边界效应与节段性铁分布不易分离。
在检测有心力衰竭风险的铁过载患者时，测量室间隔的 MRI-R2*是受边界效应影响最小的方法。
