3T 下 350μm 空间分辨率冠状动脉磁共振血管成像的可行性。
The feasibility of 350 μm spatial resolution coronary magnetic resonance angiography at 3 T in humans.
机构信息
National Institutes of Health, NIDDK, Bethesda, MD 20892, USA.
出版信息
Invest Radiol. 2012 Jun;47(6):339-45. doi: 10.1097/RLI.0b013e3182479ec4.
PURPOSE
The purposes of this study were to (1) develop a high-resolution 3-T magnetic resonance angiography (MRA) technique with an in-plane resolution approximate to that of multidetector coronary computed tomography (MDCT) and a voxel size of 0.35 × 0.35 × 1.5 mm³ and to (2) investigate the image quality of this technique in healthy participants and preliminarily in patients with known coronary artery disease (CAD).
MATERIALS AND METHODS
A 3-T coronary MRA technique optimized for an image acquisition voxel as small as 0.35 × 0.35 × 1.5 mm³ (high-resolution coronary MRA [HRC]) was implemented and the coronary arteries of 22 participants were imaged. These included 11 healthy participants (average age, 28.5 years; 5 men) and 11 participants with CAD (average age, 52.9 years; 5 women) as identified on MDCT. In addition, the 11 healthy participants were imaged using a method with a more common spatial resolution of 0.7 × 1 × 3 mm³ (regular-resolution coronary MRA [RRC]). Qualitative and quantitative comparisons were made between the 2 MRA techniques.
RESULTS
Normal vessels and CAD lesions were successfully depicted at 350 × 350 μm² in-plane resolution with adequate signal-to-noise ratio (SNR) and contrast-to-noise ratio. The CAD findings were consistent among MDCT and HRC. The HRC showed a 47% improvement in sharpness despite a reduction in SNR (by 72%) and in contrast-to-noise ratio (by 86%) compared with the regular-resolution coronary MRA.
CONCLUSION
This study, as a first step toward substantial improvement in the resolution of coronary MRA, demonstrates the feasibility of obtaining at 3 T a spatial resolution that approximates that of MDCT. The acquisition in-plane pixel dimensions are as small as 350 × 350 μm² with a 1.5-mm slice thickness. Although SNR is lower, the images have improved sharpness, resulting in image quality that allows qualitative identification of disease sites on MRA consistent with MDCT.
目的
本研究旨在：(1) 开发一种高分辨率 3T 磁共振血管造影（MRA）技术，其平面分辨率近似于多排冠状动脉 CT（MDCT），体素大小为 0.35×0.35×1.5mm³；(2) 评估该技术在健康志愿者中的图像质量，并初步评估已知冠心病（CAD）患者的图像质量。
材料与方法
本研究实施了一种优化为最小体素大小为 0.35×0.35×1.5mm³的 3T 冠状动脉 MRA 技术（高分辨率冠状动脉 MRA[HRC]），并对 22 名参与者的冠状动脉进行成像。这些参与者包括 11 名健康志愿者（平均年龄 28.5 岁；5 名男性）和 11 名经 MDCT 证实的 CAD 患者（平均年龄 52.9 岁；5 名女性）。此外，11 名健康志愿者还使用空间分辨率更为常见的 0.7×1×3mm³方法（常规分辨率冠状动脉 MRA[RRC]）进行了成像。比较了两种 MRA 技术的定性和定量指标。
结果
以 350×350μm²的平面分辨率成功显示正常血管和 CAD 病变，具有足够的信噪比（SNR）和对比噪声比（CNR）。CAD 发现与 MDCT 和 HRC 一致。与常规分辨率冠状动脉 MRA 相比，尽管 SNR（降低 72%）和 CNR（降低 86%）降低，但 HRC 的锐利度提高了 47%。
结论
本研究作为提高冠状动脉 MRA 分辨率的第一步，证明了在 3T 下获得近似于 MDCT 的空间分辨率的可行性。采集的平面像素尺寸小至 350×350μm²，层厚 1.5mm。尽管 SNR 较低，但图像的锐利度有所提高，从而使 MRA 的图像质量能够定性识别与 MDCT 一致的疾病部位。
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