动脉粥样硬化标本MRI扫描方法和序列优化

 目的 通过优化动脉粥样硬化标本的MRI扫描方法,以便标准化进行粥样硬化斑块的MRI研究.方法 取6例下肢动脉硬化闭塞症病人截肢后的股动脉.标本按两种方法处理,一种方法是直接裸标本(裸标本法),另一种是经过人工处理的标本(还原标本法).MRI用GE Signa Twinspeed 1.5T超导型磁共振仪,行常规轴位扫描,扫描序列包括SE T1WI,FSE T2WI,DOUBLE IR T1WI.观测指标:对比噪声比(CNR)和信噪比(SNR).并将数据进行t检验,双侧α＝0.05,P<0.05为有统计学意义.结果 裸标本和还原标本的对比噪声比(CNR)在T1WI、T2WI、DOUBLE IR T1WI各序列上比较均有明显统计学意义(P＝0.000).裸标本和还原标本的信噪比(SNR)在T1WI、T2WI、DOUBLE IR T1WI各序列上比较有明显统计学意义(P＝0.000).结论 还原标本的方法在对比噪声比(CNR)、信噪比(SNR)上明显优于裸标本方法.

Comparison of two methods of dealing with atherosclerotic plaque specimens for MRI

Objective To get better signal - to - noise ratio （SNR）, two methods of dealing with atherosclerotic plaque specimens for MRI were compared.Methods Six femoral arteries with atherosclemtic plagues were studied. All samples were dealt with by two methods： naked and processed. T1 - , T2 - weighted and Double IR T1WI were used in a 1.5 - T system （ GE Signa, Twinspeed）. Contrast - to - noise ratio （CNR） and SNR were compared between the two methods. For T1 - , T2 - weighted and Double IR T1WI, parameters such as TR and TE, a field of view of matrix was better collected. Results Both CNR and SNR in Tl - , T2 - weighted and Double IR T1WI between naked samples and processed samples were significantly different （ P 〈 0.01 ） ; they were better in formers than in latters. Conclusions CNR and SNR in processed samples are superior to those in naked samples for MRI.