Rapid Whole-Brain Magnetic Resonance Imaging With Isotropic Resolution at 3 Tesla
Rapid Whole-Brain Magnetic Resonance Imaging With Isotropic Resolution at 3 Tesla
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DOI：
10.1097/rli.0b013e31818eee3c
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发表时间：
2009-01-01
影响因子：
6.7
通讯作者：
Carrillo, Andres
中科院分区：
文献类型：
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作者：
Edelman, Robert R.;Dunkle, Eugene;Carrillo, Andres
各向同性成像通过在不损失空间分辨率的情况下实现正交图像重建而提供了改善病变检测和成像效率的潜力。然而，T1加权各向同性数据采集的冗长扫描时间一直是这种方法的常规临床应用的障碍。我们测试了在3特斯拉下使用改进的信噪比进行快速全脑T1加权成像的可行性，其中各向同性0.8 mm x 0.8 x 0.8 mm（0.51 mm（3））体素。该方法在健康志愿者和患者中进行了验证。8名健康受试者在3特斯拉MR系统上进行了增强前后的成像。T1加权，三维扰相梯度回波（3D SPGR）数据采集在0.8毫米层厚和重建在2毫米厚在3个正交方向。扫描时间为4分42秒。该技术进行了比较，与反演恢复准备扰相梯度回波（SPGR-IR）和二维自旋回波（SE）的可比空间分辨率和扫描时间。然后在一系列10例增强的脑病变患者中与2D SE进行比较，3D SPGR技术提供的对比噪声比（CNR）约为SPGR-IR的两倍，并且在区分灰质和白色物质方面比2D SE高50%。非参数分析显示，志愿者（P < 0.05）和有强化病变的患者（P <0.05）的3D SPGR图像质量评分也显著较高。特别值得注意的是消除了对比后血管脉动伪影，这在2D SE中常见。脑脊液低信号较均匀。2D SE和3D SPGR.Our研究结果表明，使用亚毫米体素在3特斯拉下进行快速全脑各向同性成像的可行性。伪影最小，特别是与2D SE相比，而CNR比SPGR-IR好2倍。与在多个平面中采集的2D采集相比，从单次各向同性采集创建正交方向的重新格式化图像的能力大大提高了效率。尽管需要在更大的患者队列中进行进一步的临床研究。这些初步结果表明该技术具有很大的临床前景。
Isotropic imaging offers the potential of improving lesion detection and imaging efficiency by enabling orthogonal image reformations without loss of spatial resolution. However, lengthy scan times for T1-weighted isotropic data acquisitions have been an impediment to the routine clinical application of this approach. We tested the feasibility of using the improved signal-to-noise ratio at 3 Tesla to perform rapid, whole-brain T1-weighted imaging with isotropic 0.8 mm x 0.8 into x 0.8 mm (0.51 mm(3)) voxels. The method was validated in healthy volunteers and patients.Eight healthy subjects were imaged pre- and postcontrast on a 3 Tesla MR system. T1-weighted, 3-dimensional spoiled gradient-echo (3D SPGR) data were acquired at 0.8-mm slice thickness and reconstructed at 2-mm thickness in 3 orthogonal orientations. Scan time was 4 minutes 42 seconds. The technique was compared with inversion recovery-prepared spoiled gradient-echo (SPGR-IR) and 2D spin-echo (SE) for comparable spatial resolution and scan time. It was then tested in comparison with 2D SE in a series of 10 patients with enhancing brain lesions.The 3D SPGR technique provided approximately twice the contrast-to-noise ratio (CNR) of SPGR-IR and 50% greater CNR than 2D SE for discriminating gray and white matter. Image quality ratings, evaluated with nonparametric analyses, were also significantly higher for 3D SPGR in both volunteers (P < 0.05) and patients with enhancing lesions (P < 0.05). Of particular note was the elimination of postcontrast vessel pulsation artifacts, which were commonly present with 2D SE. and more uniform hypointensity of cerebrospinal fluid. Lesion enhancement in patients did not differ significantly for 2D SE and 3D SPGR.Our results demonstrate the feasibility of rapid, whole-brain isotropic imaging at 3 Tesla using submillimeter voxels. Artifacts were minimal, especially compared with 2D SE, whereas CNR was 2-fold better than SPGR-IR. The capability for creating reformatted images in orthogonal orientations from a single isotropic acquisition greatly improves efficiency compared with 2D acquisitions acquired in multiple planes. Although further clinical study is needed in a larger patient cohort. these initial results suggest substantial clinical promise for the technique.