MR imaging of the fetal brain at 1.5T and 3.0T field strengths: comparing specific absorption rate (SAR) and image quality.
MR imaging of the fetal brain at 1.5T and 3.0T field strengths: comparing specific absorption rate (SAR) and image quality.
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DOI：
10.1515/jpm-2014-0268
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发表时间：
2015-03
影响因子：
2.4
通讯作者：
Romero R
中科院分区：
文献类型：
--
作者：
Krishnamurthy U;Neelavalli J;Mody S;Yeo L;Jella PK;Saleem S;Korzeniewski SJ;Cabrera MD;Ehterami S;Bahado-Singh RO;Katkuri Y;Haacke EM;Hernandez-Andrade E;Hassan SS;Romero R
1)评价采用快速自旋回波序列在3.0T场强下进行胎儿脑磁共振成像（MRI）的可行性，射频（rf）能量沉积（以比吸收率SAR测量）低于1.5T；2)比较1.5T和3.0T MRI的图像质量、组织对比度和显著性。将1.5T时胎儿大脑的T2加权图像与同一胎儿在3.0T时使用改良序列获得的类似数据进行比较。定量全身SAR和归一化图像信噪比；以及基于诊断图像质量和大脑特定解剖结构的组织对比度和显著性评估的名义评分方案，在1.5T和3.0T之间进行比较。12例孕妇行1.5T和3.0T MRI检查。与1.5T相比，3.0T图像的图像信噪比显著提高（p=0.03），全身SAR显著降低（p < 0.0001）。两种场强下的所有病例均被评为具有诊断图像质量。3.0T MRI（与1.5T相比）的图像：1)组织对比效果相同（57%,21/37）或更好（35%,13/37）；2)相同（61%,20/33）或更高（33%,11/33）的显著性。与1.5T相比，3.0T时可以获得更高分辨率和更好信噪比的胎儿脑图像，同时SAR降低。与1.5T相比，3.0T时获得的胎儿脑图像显示出更好的组织对比度和显著性。
1) To evaluate the feasibility of fetal brain magnetic resonance imaging (MRI) using a fast spin echo sequence at 3.0T field strength with low radio frequency (rf) energy deposition (as measured by specific absorption rate – SAR) than 1.5T; 2) and to compare image quality, tissue contrast and conspicuity between 1.5T and 3.0T MRI. T2 weighted images of the fetal brain at 1.5T were compared to similar data obtained in the same fetus using a modified sequence at 3.0T. Quantitative whole body SAR and normalized image signal to noise ratio (SNR); and a nominal scoring scheme based evaluation of diagnostic image quality and tissue contrast & conspicuity for specific anatomical structures in the brain, were compared between 1.5T and 3.0T. 12 pregnant women underwent both 1.5T and 3.0T MRI examinations. The image SNR was significantly higher (p=0.03) and whole body SAR was significantly lower (p < 0.0001) for images obtained at 3.0T compared to 1.5T. All cases at both field strengths were scored as having diagnostic image quality. Images from 3.0T MRI (compared to 1.5T) were: 1) equal (57%; 21/37) or superior (35%; 13/37) for tissue contrast; and 2) equal (61%; 20/33) or superior (33%, 11/33) for conspicuity. It is possible to obtain fetal brain images with higher resolution and better SNR at 3.0T with simultaneous reduction in SAR compared to 1.5T. Images of the fetal brain obtained at 3.0T demonstrated superior tissue contrast and conspicuity compared to 1.5T.