自制血管内成像天线在3.0T MR成像中可行性的实验研究

自制血管内成像天线在3.0T MR成像中可行性的实验研究

内容简介：目的 探讨利用自制的MR血管内成像天线在3.0TMR动脉管壁成像中的可行性.方法 自制的血管内MR单极天线(ILMA),包括无屏蔽的镍钛诺超滑导丝和调谐匹配电路.其中无屏蔽导丝作为接收天线,其直径0.019 in(1 in=2.54 cm)、长度23.11 in.利用该成像导丝在3.0TMR扫描仪上进行体外水模实验和在体动物(对4只新西兰白兔进行腹主动脉管壁检查)实验,结果与相同扫描参数下的相控阵线圈的图像信噪比(SNR)和对比噪声比(CNR)等反映图像质量的指标通过配对t检验进行比较.结果 MR检查中,自制ILMA最佳空间分辨率为313 μm,证实了ILMA对管壁成像的可行性；且Matlab分析软件得到SNR图显示ILMA获得的水膜平均SNR(86.8 ±0.8)高于利用相同序列、参数、层面扫描的相控阵线圈的SNR(9.9 ±0.1),差异有统计学意义(t=313.09,P＜0.01).4只动物成功完成腹主动脉ILMA及相控阵线圈的MR检查,ILMA T1WI测得SNR分别为60.4±20.9、61.3 ±22.5、59.8 ±20.4、32.3 ±22.6,T2 WI测得SNR分别为51.2 ±21.6、49.8±15.5、50.4±17.2、22.4±18.3；T1WI测得CNR分别为19.8±8.1、18.9±9.2、19.6±11.8、20.7±13.3；T2 WI测得CNR分别为17.7±6.4、18.6±6.9、17.2±6.4、17.2±6.4.同层面ILMA与相控阵线圈扫描的SNR相比,4只动物T1WI扫描的f值分别为:6.36、3.84、3.51、6.92,T2WI扫描的t值分别为3.47、4.89、6.35、4.21；CNR相比,T1WI扫描的t值分别为3.56、3.97、-0.71、4.74,T2 WI扫描的t值分别为3.99、3.01、4.27、5.03.除19层T1WI扫描,两者的CNR相比P＞0.05外,其余P值均＜0.05.结论 自制血管内成像天线在3.0TMR动物体内成像是可行的,且较传统的相控阵线圈可获得更高的SNR.

Abstract：Objective The study was to investigate the feasibility of using an intravascular Loopless Monopole Antenna (ILMA) for 3.0 T MR imaging of water bath and deep-seated arterial walls of experimental animal.Methods A novel intravascular loopless monopole antenna (ILMA) was developed,including a non-shield loach guide-wire and a matching circuit.The non-shield loach guide-wire is used as a receive antenna,with the diameter of 0.019 in( 1 in =2.54 cm) and length of 23.11 in.During the MR scanning,the ILMA was used as a receive-only probe,while body coil was used to transmit the RF pulses.Utilizing the coil in water bath and in-vivo animal experiment,we measured signal-to-noise ratio (SNR) and contrast-to-noise ratio(CNR) of artery wall using the same scanning parameter compared with phased-array coil.Results In the study,the developed novel ILMA conduced to improved SNR of imaging and much higher space resolution( 313 μm).First,the feasibility of acquiring the wall images was demonstrated on phantoms.The SNRs map generated by the matlab software showed that in comparison with the phased-array coil,ILMA generated higher SNR of the phantom wall when using the same sequences,parameters,and slices (86.8 ±0.8 vs.9.9 ±0.1,P ＜0.01 ).When imaging the aorta wall with the ILMA and phased-array coil,the SNRs of the arterial wall with the ILMA is 60.4 ±20.9,61.3 ±22.5,59.8 ±20.4,32.3 ±22.6 (T1WI),51.2 ±21.6,49.8 ± 15.5,50.4 ± 17.2,22.4 ± 18.3 (T2WI),the CNRs of the aorta wall with theILMA is 19.8±8.1,18.9±9.2,19.6±11.8,20.7 ± 13.3(T1WI),17.7±6.4,18.6±6.9,17.2 ± 6.4,17.2 ± 6.4 ( T2 WI),compared with phased-array coil,t values SNR:6.36,3.84,3.51,6.92(T1 WI),3.47,4.89,6.35,4.21 (T2WI),CNR:3.56,3.97,-0.71,4.74 (T1WI),3.99,3.01,4.27,5.03(T2 WI,P ＜ 0.05 ),respectively.Conclusion The study demonstrates the capability of using an MR ILMA to generate 3.0 T MR in-vivo experiments,the developed novel ILMA conduces to increased SNR compared with the conventional phased-array coil.

作者：张臣, 赵蕾, 马晓海, 袁宏阳, 张珏, 张兆琪,

关键词：磁共振成像,介入性, 动脉, 动物实验, 血管内成像天线,