Mani Venkatesh, Briley-Saebo Karen C, Hyafil Fabien, Fayad Zahi A
Imaging Science Laboratories, Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
Magn Reson Med. 2006 Nov;56(5):1096-106. doi: 10.1002/mrm.21060.
In vivo markers that allow for detection of ferritin within atheromatous plaque may be useful for identifying iron-catalyzed hydroxyl-radical formation and subsequent lipid peroxidation. Recently, a positive contrast MR technique--GRadient echo Acquisition for Superparamagnetic particles/suscePtibility (GRASP)--was used to identify the presence of magnetic entities in phantom models. The aim of the current study was to determine the feasibility of using GRASP in conjunction with conventional T(2) ()-weighted (T(2) ()W) gradient-echo (GRE) sequences for identifying ferritin/hemosiderin deposition using in vitro and in vivo models of thrombus. In vitro thrombi were prepared by incubating blood with ferritin. MRI was performed using conventional GRE sequences and GRASP. The results indicate that GRASP was able to verify ferritin deposition in in vitro thrombi. In vivo thrombi were created using a crush injury model in rabbits. The signal enhancement obtained using conventional GRE sequences and GRASP was compared with the location of iron deposition by histology. In all of the animals the GRASP signal correlated with signal loss by conventional GRE, and ferritin/hemosiderin deposition by histology. GRASP sequences in combination with conventional GRE sequences may be used to detect the presence of ferritin deposition in in vitro thrombi and in vivo crush-injured rabbit carotid arteries.
能够检测动脉粥样斑块内铁蛋白的体内标志物，可能有助于识别铁催化的羟基自由基形成及随后的脂质过氧化。最近，一种阳性对比磁共振技术——超顺磁性颗粒/磁化率梯度回波采集（GRASP）——被用于在体模模型中识别磁性实体的存在。本研究的目的是确定使用GRASP结合传统的T(2)*加权（T(2)*W）梯度回波（GRE）序列，利用体外和体内血栓模型识别铁蛋白/含铁血黄素沉积的可行性。通过将血液与铁蛋白孵育制备体外血栓。使用传统GRE序列和GRASP进行磁共振成像。结果表明，GRASP能够验证体外血栓中铁蛋白的沉积。使用兔挤压伤模型创建体内血栓。将使用传统GRE序列和GRASP获得的信号增强与通过组织学确定的铁沉积位置进行比较。在所有动物中，GRASP信号与传统GRE序列的信号丢失以及组织学上的铁蛋白/含铁血黄素沉积相关。GRASP序列与传统GRE序列相结合，可用于检测体外血栓和体内挤压伤兔颈动脉中铁蛋白沉积的存在。
