Liu Hao-Li, Hsu Po-Hong, Chu Po-Chun, Wai Yau-Yau, Chen Jin-Chung, Shen Chia-Rui, Yen Tzu-Chen, Wang Jiun-Jie
Department of Electrical Engineering, Chang-Gung University, Taiwan.
J Magn Reson Imaging. 2009 Jan;29(1):31-8. doi: 10.1002/jmri.21599.
To investigate the usefulness of a fully flow-compensated heavy T2*-weighted imaging enhanced by superparamagnetic iron oxide (SPIO) particles for distinguishing between focused ultrasound-induced disruption of blood-brain barrier (BBB) and brain hemorrhage.
Focused ultrasound (frequency: 1.5 MHz) was used to induce disruption of the BBB in 39 rats. Two T2*-weighted images were obtained before and after SPIO administration. Preenhanced T2*-weighted images were used to detect hemorrhage. Detection of BBB disruption was performed on SPIO-enhanced images. Thirty-four rats were sacrificed after magnetic resonance (MR) scanning for histological confirmation of brain lesions. The remaining five animals were followed up for 35 days. Prussian blue staining was performed on histological sections to detect SPIO particles in the brain.
After SPIO injection the areas of BBB disruption in rat brain were significantly enlarged. The area of mismatch between the T2*-weighted images indicated a safe region where BBB opening occurred without hemorrhagic complications. In the longitudinal study, removal of SPIO occurred at a faster rate in hemorrhagic areas, albeit being closer to that occurring in the liver. The presence of SPIO was confirmed by Prussian blue staining in brain parenchyma and capillary endothelial cells in areas of BBB disruption.
T2*-weighted images-either with and without SPIO enhancement-may differentiate focused ultrasound-induced BBB disruption from brain hemorrhage.
探讨超顺磁性氧化铁（SPIO）颗粒增强的全血流补偿重T2*加权成像在区分聚焦超声诱导的血脑屏障（BBB）破坏和脑出血方面的作用。
使用聚焦超声（频率：1.5MHz）诱导39只大鼠的血脑屏障破坏。在注射SPIO前后分别获取了两张T2加权图像。增强前的T2加权图像用于检测出血情况。在SPIO增强图像上进行血脑屏障破坏的检测。34只大鼠在磁共振（MR）扫描后处死，用于对脑损伤进行组织学确认。其余5只动物进行了35天的随访。对组织切片进行普鲁士蓝染色以检测脑中的SPIO颗粒。
注射SPIO后，大鼠脑中血脑屏障破坏的区域明显扩大。T2*加权图像之间的不匹配区域表明是一个安全区域，在该区域发生了血脑屏障开放且无出血并发症。在纵向研究中，SPIO在出血区域的清除速度更快，尽管更接近肝脏中的清除速度。通过普鲁士蓝染色在血脑屏障破坏区域的脑实质和毛细血管内皮细胞中证实了SPIO的存在。
T2*加权图像（无论有无SPIO增强）可区分聚焦超声诱导的血脑屏障破坏和脑出血。
