Kim I Y, Mitchell D G, Vinitski S, Consigny P M, Hann H W, Rifkin M D, Rubin R
Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA.
J Magn Reson Imaging. 1993 Jan-Feb;3(1):67-70. doi: 10.1002/jmri.1880030112.
To investigate the relationship of hepatic signal intensity and T2 with histologic grading in an animal model of oral iron overload and to determine the duration of feeding necessary to produce abnormalities detectable on magnetic resonance (MR) images, hepatic iron overload was induced in 12 rats by feeding them a diet supplemented with 4% carbonyl iron for 2-11 weeks. Iron overload seen on MR images was graded independently and blindly by two radiologists as normal, mild, moderate, or severe. The rats were killed, and histologic findings were graded blindly by four pathologists using a similar subjective scale. Hepatic T2 values were estimated from spin-echo images. In the rats with iron overload, intracellular iron deposition was noted on histologic studies. On MR images, hepatic signal intensity and T2 decreased after only 2 weeks of dietary iron overload, and both continued to decrease with longer duration of feeding. There was significant correlation between iron overload duration and changes on MR images and between MR images and histologic grading (r = .92, P = .0001 for both). The mean T2 of hepatic iron overload decreased with longer duration of feeding.
为了研究口服铁过载动物模型中肝脏信号强度和T2与组织学分级的关系，并确定产生磁共振（MR）图像上可检测到的异常所需的喂养持续时间，通过给12只大鼠喂食补充有4%羰基铁的饮食2至11周，诱导其肝脏铁过载。由两名放射科医生独立且盲法地将MR图像上所见的铁过载分为正常、轻度、中度或重度。处死大鼠，由四名病理学家使用类似的主观量表对组织学结果进行盲法分级。从自旋回波图像估计肝脏T2值。在铁过载的大鼠中，组织学研究发现细胞内有铁沉积。在MR图像上，饮食性铁过载仅2周后肝脏信号强度和T2就降低了，并且随着喂养持续时间延长两者持续降低。铁过载持续时间与MR图像变化之间以及MR图像与组织学分级之间存在显著相关性（两者r均为0.92，P均为0.0001）。肝脏铁过载的平均T2随着喂养持续时间延长而降低。
