Zhang Zhuoli, Fan Zhaoyang, Carroll Timothy J, Chung YiuCho, Weale Peter, Jerecic Renate, Li Debiao
Department of Radiology, Northwestern University, Chicago, IL, USA.
Invest Radiol. 2009 Sep;44(9):619-26. doi: 10.1097/RLI.0b013e3181b4c218.
To evaluate the potential use of a novel 3D turbo spin-echo (TSE) T2-weighted (T2w) technique for assessing the vessel wall in the superficial femoral artery at 3.0 T.
Magnetic resonance imaging can be used for the noninvasive assessment of atherosclerotic plaque burden in the peripheral circulation. Although black-blood 2D TSE techniques have been used for femoral arterial wall imaging, these techniques require prolonged imaging time to cover a large field of view required to cover the leg. Recently, variable-flip-angle 3D TSE T2w (SPACE) has been introduced as a fast vessel wall imaging technique with submillimeter spatial resolution. A systematic investigation of the application of this technique to femoral arterial wall imaging has yet to be performed.
Fifteen healthy volunteers and 3 patients with peripheral arterial disease (PAD) underwent 3D SPACE imaging of the superficial femoral artery at 3.0 T, with the conventional 2D TSE T2w imaging as a reference. Muscle-lumen contrast to noise ratio (CNR) and wall/lumen volumes (WV, LV) were measured at the matched locations on the 3D and 2D image sets. Statistical comparison on a per-subject basis was conducted to determine the difference and agreement between 3D SPACE and the 2D TSE techniques.
The 3D SPACE data sets enabled vessel visualization from arbitrary orientation through multiplanar reformation technique. Muscle-lumen CNR was significantly higher with 3D SPACE than with the 2D TSE (3.12 +/- 0.84 vs. 2.17 +/- 0.34, P < 0.01). This trend was confirmed when CNR efficiency (CNR(eff)) values were further compared. A similar trend was observed in PAD patients (SPACE vs. 2D TSE T2w: CNR 2.35 +/- 0.13 vs. 1.77 +/- 0.25; CNR(eff) 15.35 +/- 0.61 vs. 3.59 +/- 2.62. all P < 0.05). Measurements of WV and LV from the 3D and 2D techniques were highly correlated in volunteers and PAD patients (volunteers, WV: linear regression r2 = 0.98, LV: r2 = 0.98, P < 0.001 for both; patients, WV: linear regression r2 = 0.96, LV: r2 = 0.94, P < 0.001 for both).
We established the feasibility of using the 3D SPACE technique for vessel wall imaging in the superficial femoral artery at 3.0T. High, isotropic-resolution SPACE images, with the aid of multiplanar reformation, enable superior vessel wall visualization. Superior blood signal suppression comparable to vessel wall morphologic measurements, and superior time efficiency compared to conventional 2D TSE imaging indicate the great potential of the SPACE method as a noninvasive imaging technique for the assessment of atherosclerotic plaque burden in PAD patients.
评估一种新型三维快速自旋回波（TSE）T2加权（T2w）技术在3.0 T场强下评估股浅动脉血管壁的潜在应用价值。
磁共振成像可用于对外周循环中动脉粥样硬化斑块负荷进行无创评估。尽管黑血二维TSE技术已用于股动脉壁成像，但这些技术需要较长的成像时间来覆盖腿部所需的大视野。最近，可变翻转角三维TSE T2w（SPACE）作为一种具有亚毫米空间分辨率的快速血管壁成像技术被引入。该技术应用于股动脉壁成像的系统研究尚未开展。
15名健康志愿者和3名外周动脉疾病（PAD）患者在3.0 T场强下接受股浅动脉的三维SPACE成像，以传统二维TSE T2w成像作为对照。在三维和二维图像集的匹配位置测量肌肉-管腔对比噪声比（CNR）以及血管壁/管腔体积（WV，LV）。进行基于个体的统计比较，以确定三维SPACE与二维TSE技术之间的差异和一致性。
三维SPACE数据集通过多平面重组技术可从任意方向实现血管可视化。三维SPACE的肌肉-管腔CNR显著高于二维TSE（3.12±0.84 vs. 2.17±0.34，P<0.01）。当进一步比较CNR效率（CNR(eff)）值时，这一趋势得到证实。在PAD患者中也观察到类似趋势（SPACE vs. 二维TSE T2w：CNR 2.35±0.13 vs. 1.77±0.25；CNR(eff) 15.35±0.61 vs. 3.59±2.62，均P<0.05）。在志愿者和PAD患者中，三维和二维技术测量的WV和LV高度相关（志愿者，WV：线性回归r2 = 0.98，LV：r2 = 0.98，两者P<0.001；患者，WV：线性回归r2 = 0.96，LV：r2 = 0.94，两者P<0.001）。
我们证实了在3.0 T场强下使用三维SPACE技术对股浅动脉血管壁成像的可行性。高各向同性分辨率的SPACE图像，借助多平面重组，能实现更好的血管壁可视化。与血管壁形态学测量相当的出色血液信号抑制，以及与传统二维TSE成像相比更高的时间效率，表明SPACE方法作为一种用于评估PAD患者动脉粥样硬化斑块负荷的无创成像技术具有巨大潜力。
