Katoh Marcus, Buecker Arno, Stuber Matthias, Günther Rolf W, Spuentrup Elmar
Department of Diagnostic Radiology, University Hospital, University of Technology, Aachen, Germany.
Kidney Int. 2004 Sep;66(3):1272-8. doi: 10.1111/j.1523-1755.2004.00882.x.
The aim of our study was the investigation of a novel navigator-gated three-dimensional (3D) steady-state free-precession (SSFP) sequence for free-breathing renal magnetic resonance angiography (MRA) without contrast medium, and to examine the advantage of an additional inversion prepulse for improved contrast.
Eight healthy volunteers (mean age 29 years) and eight patients (mean age 53 years) were investigated on a 1.5 Tesla MR system (ACS-NT, Philips, Best, The Netherlands). Renal MRA was performed using three navigator-gated free-breathing cardiac-triggered 3D SSFP sequences [repetition time (TR) = 4.4 ms, echo time (TE) = 2.2 ms, flip angle 85 degrees, spatial resolution 1.25 x 1.25 x 4.0 mm(3), scanning time approximately 1 minute 30 seconds]. The same sequence was performed without magnetization preparation, with a non-slab selective and a slab-selective inversion prepulse. Signal-to-noise ratio (SNR), contrast-to-noise (CNR) vessel length, and subjective image quality were compared.
Three-dimensional SSFP imaging combined with a slab-selective inversion prepulse enabled selective and high contrast visualization of the renal arteries, including the more distal branches. Standard SSFP imaging without magnetization preparation demonstrated overlay by veins and renal parenchyma. A non-slab-selective prepulse abolished vessel visualization. CNR in SSFP with slab-selective inversion was 43.6 versus 10.6 (SSFP without magnetization preparation) and 0.4 (SSFP with non-slab-selective inversion), P < 0.008.
Navigator-gated free-breathing cardiac-triggered 3D SSFP imaging combined with a slab-selective inversion prepulse is a novel, fast renal MRA technique without the need for contrast media.
我们研究的目的是探究一种新型导航门控三维（3D）稳态自由进动（SSFP）序列用于自由呼吸下无对比剂的肾脏磁共振血管造影（MRA），并检验附加反转预脉冲以改善对比度的优势。
在一台1.5特斯拉磁共振系统（ACS-NT，飞利浦，荷兰贝斯特）上对8名健康志愿者（平均年龄29岁）和8名患者（平均年龄53岁）进行研究。使用三个导航门控自由呼吸心脏触发的3D SSFP序列进行肾脏MRA [重复时间（TR）= 4.4毫秒，回波时间（TE）= 2.2毫秒，翻转角85度，空间分辨率1.25×1.25×4.0毫米³，扫描时间约1分30秒]。在不进行磁化准备、使用非层面选择和层面选择反转预脉冲的情况下执行相同序列。比较信噪比（SNR）、对比噪声比（CNR）、血管长度和主观图像质量。
三维SSFP成像结合层面选择反转预脉冲能够选择性且高对比度地显示肾动脉，包括更远端的分支。不进行磁化准备的标准SSFP成像显示有静脉和肾实质的重叠。非层面选择预脉冲使血管无法显示。层面选择反转的SSFP中的CNR为43.6，而无磁化准备的SSFP为10.6，非层面选择反转的SSFP为0.4，P < 0.008。
导航门控自由呼吸心脏触发的3D SSFP成像结合层面选择反转预脉冲是一种无需对比剂的新型快速肾脏MRA技术。
