Willinek Winfried A, Bayer Thomas, Gieseke Jürgen, von Falkenhausen Marcus, Sommer Torsten, Hoogeveen Romhild, Wilhelm Kai, Urbach Horst, Schild Hans H
Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105, Bonn, Germany.
Eur Radiol. 2007 Mar;17(3):618-25. doi: 10.1007/s00330-006-0406-z. Epub 2006 Aug 30.
To examine whether the the increased signal-to-noise (S/N) available at 3.0T would permit the use of the quadrature body coil for high spatial resolution contrast-enhanced (CE) MR angiography (MRA), and whether the large FOV that was used in our routine 1.5T protocol would also be feasible at 3.0T. In a prospective study, 43 patients and five volunteers were examined on a clinical whole-body 3.0T MR unit (Intera, Philips Medical Systems, Best, The Netherlands) after institutional review board approval and informed consent. Three-dimensional CE MRA (T1 gradient echo-sequence with TR/TE = 5.7/1.93 msec.; acquisition time, 1:54 min.) using randomly segmented central k-space ordering (CENTRA) was acquired with the quadrature body coil, using over a FOV of 350 mm. A high-image matrix of 432x432 yielded a non-zero filled voxel size of 0.81 mm x 0.81 mm x 1.0 mm (0.66 mm(3)). For quantitative analysis, contrast ratios (CR) between vessels (S) and signal in surrounding tissue (ST) were calculated [(S-ST)/(S+ST)]. For qualitative analysis, image quality and presence of artifacts were rated by two radiologists in consensus on a five-point scale (1=excellent to 5=nondiagnostic). Digital subtraction angiography (DSA) served as the standard of reference in patients with vascular disease. In the five volunteers, 1.5T CE MRA using a phased array neurovascular coil was available for intraindividual comparison. 3.0T CE MRA was successfully performed in 48/48 subjects (100%). Mean CR+/- SD were 0.76 (139.30/182.42) and 0.87 (235.18/270.14) at 3.0T and 1.5T respectively . Mean image quality was 3.82+/-0.86. Intraindividual comparison between 1.5T and 3.0T CE MRA in the volunteers revealed no significant difference in image quality (4.2+/-0.74 vs 4.6+/-0.80; p>0.05). Vascular disease was correctly identified in 13/13 patients with DSA correlation. CE MRA of the supraaortic arteries is feasible at 3.0T using a large FOV of 350 mm. The signal gain at 3.0T enables high spatial resolution contrast-enhanced MR angiography by using the built-in quadrature body coil only.
为了研究3.0T时可用的更高信噪比(S/N)是否允许使用体部正交线圈进行高空间分辨率对比增强(CE)磁共振血管造影(MRA),以及我们常规1.5T协议中使用的大视野在3.0T时是否也可行。在一项前瞻性研究中,经机构审查委员会批准并获得知情同意后,对43例患者和5名志愿者在临床全身3.0T磁共振单元(Intera,飞利浦医疗系统公司,荷兰贝斯特)上进行了检查。使用随机分段中心k空间排序(CENTRA)的三维CE MRA(T1梯度回波序列,TR/TE = 5.7/1.93毫秒;采集时间,1:54分钟)通过体部正交线圈在350mm的视野上采集。432x432的高图像矩阵产生了0.81mm x 0.81mm x 1.0mm(0.66mm³)的非零填充体素大小。为了进行定量分析,计算血管(S)与周围组织信号(ST)之间的对比率(CR)[(S - ST)/(S + ST)]。为了进行定性分析,由两名放射科医生共同以五点量表(1 = 优秀至5 = 无法诊断)对图像质量和伪影的存在进行评分。数字减影血管造影(DSA)作为血管疾病患者的参考标准。在5名志愿者中,可以获得使用相控阵神经血管线圈的1.5T CE MRA用于个体内比较。48/48名受试者(100%)成功进行了3.0T CE MRA。3.0T和1.5T时的平均CR±SD分别为0.76(139.30/182.42)和0.87(235.18/270.14)。平均图像质量为3.82±0.86。志愿者中1.5T和3.0T CE MRA的个体内比较显示图像质量无显著差异(4.2±0.74对4.6±0.80;p>0.05)。13例与DSA相关的患者中血管疾病均被正确识别。使用350mm的大视野在3.0T时进行主动脉弓上动脉的CE MRA是可行的。3.0T时的信号增益仅通过使用内置的体部正交线圈就能实现高空间分辨率对比增强磁共振血管造影。