Yamashita Y, Mitsuzaki K, Tang Y, Namimoto T, Takahashi M
Department of Radiology, Kumamoto University School of Medicine, Japan.
J Magn Reson Imaging. 1997 Jul-Aug;7(4):623-8. doi: 10.1002/jmri.1880070403.
MR angiography (MRA) was performed in 50 consecutive subjects (mean age, 59 years), who had been referred for abdominal MRA, on a 1.5-T superconductive unit that used a body phased-array coil. Three breath-hold three-dimensional sequences were evaluated both in phantom and clinical studies: (a) standard fast three-dimensional gradient-echo sequence (TR = 15, TE = 6; imaging time, 32 seconds), (b) ultrafast three-dimensional gradient-echo sequence (TR = 8.2, TE = 3; imaging time, 18 seconds), and (c) ultrafast magnetization-prepared (MP) rapid acquisition gradient echo (RAGE) (TR = 5.8, TE = 2.9, inversion time [TI] = 20; imaging time, 15 seconds). The initial 30 patients were randomized into three groups by three separate sequences. For the remaining 20 patients, ultrafast-gradient-echo and ultrafast MP-RAGE sequences were performed. Conventional angiography was performed on 36 patients. Signal measurements of the phantom and clinical images of the aorta, visceral branches of the aorta, iliac arteries, inferior vena cavae, and portal veins were performed. The overall image quality and background fatty tissue contrast of the vessels were rated subjectively. Comparison of images between MRA and conventional angiography also was performed. The contrast between the vessels and background fatty tissue was significantly higher in the ultrafast MP-RAGE sequence in both quantitative and qualitative analysis, and image-quality ultrafast MP-RAGE was superior to the other two sequences (P < .01). The aorta and iliac arteries could be visualized in all pulse sequences, and abnormalities of these vessels were diagnosed correctly. The renal artery was visualized more clearly with the two ultrafast sequences.
对50例连续的受试者(平均年龄59岁)进行了磁共振血管造影(MRA)检查,这些受试者因腹部MRA检查被转诊至一台使用体部相控阵线圈的1.5T超导设备。在体模和临床研究中评估了三种屏气三维序列:(a)标准快速三维梯度回波序列(TR = 15,TE = 6;成像时间32秒),(b)超快三维梯度回波序列(TR = 8.2,TE = 3;成像时间18秒),以及(c)超快磁化准备(MP)快速采集梯度回波(RAGE)序列(TR = 5.8,TE = 2.9,反转时间[TI] = 20;成像时间15秒)。最初的30例患者通过三种不同的序列随机分为三组。对于其余20例患者,进行了超快梯度回波序列和超快MP-RAGE序列检查。对36例患者进行了传统血管造影。对体模以及主动脉、主动脉内脏分支、髂动脉、下腔静脉和门静脉的临床图像进行了信号测量。对血管的整体图像质量和背景脂肪组织对比度进行主观评分。还对MRA图像和传统血管造影图像进行了比较。在定量和定性分析中,超快MP-RAGE序列中血管与背景脂肪组织之间的对比度均显著更高,且超快MP-RAGE序列的图像质量优于其他两个序列(P <.01)。在所有脉冲序列中均可显示主动脉和髂动脉,并且这些血管的异常均被正确诊断。使用两种超快序列能更清晰地显示肾动脉。