MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
J Magn Reson Imaging. 2012 Jun;35(6):1332-7. doi: 10.1002/jmri.23599. Epub 2012 Feb 7.
To examine changes in the brain before liver transplantation caused by the accumulation of paramagnetic ion deposits and to investigate recovery after liver transplantation over a long-term horizon.
Fifteen patients indicated for liver transplantation, 26 patients up to 2 years after, and 40 patients 8-15 years after liver transplantation were subjected to MR relaxometry. T(1) and T(2) relaxation times in the basal ganglia, thalamus, and white matter were evaluated.
Relaxometry revealed a shortening of the relaxation times due to the deposition of paramagnetic ions in the basal ganglia before liver transplantation (P < 0.05), complete normalization of the relaxation times shortly after transplantation in the globus pallidus and caudate nucleus, and partial recovery of T(2) in the putamen. Relaxation times remained stable even 15 years posttransplantation. Increased relaxation times posttransplantation were found in the white matter and thalamus.
The shortening of the relaxation times observed in the basal ganglia before liver transplantation was caused by paramagnetic ion deposition. The recovery observable within 2 years after transplantation was permanent, and no recurrence of paramagnetic ion deposition was observed even 15 years posttransplantation. Changes in the white matter and thalamus after transplantation were attributed to damage caused by permanent exposure to immunosuppressants.
研究肝移植前因顺磁性离子沉积导致的脑内变化,并探讨肝移植后长期的脑恢复情况。
对 15 例肝移植前患者、26 例肝移植后 2 年内患者和 40 例肝移植后 8-15 年患者进行磁共振弛豫度测定。评估基底节、丘脑和白质的 T1 和 T2 弛豫时间。
弛豫度测定显示,肝移植前由于顺磁性离子沉积,基底节的弛豫时间缩短(P < 0.05),移植后短期内苍白球和尾状核的弛豫时间完全正常,壳核的 T2 部分恢复。即使在移植后 15 年,弛豫时间仍保持稳定。移植后白质和丘脑的弛豫时间增加。
肝移植前基底节观察到的弛豫时间缩短是由顺磁性离子沉积引起的。移植后 2 年内观察到的恢复是永久性的,即使在移植后 15 年也未观察到顺磁性离子沉积的复发。移植后白质和丘脑的变化归因于长期暴露于免疫抑制剂造成的损害。