Theisen Daniel, Wintersperger Bernd J, Huber Armin, Dietrich Olaf, Reiser Maximilian F, Schönberg Stefan O
Department of Clinical Radiology, Ludwig-Maximilians-University of Munich, Campus Grosshadern, Munich, Germany.
Invest Radiol. 2007 Jul;42(7):499-506. doi: 10.1097/RLI.0b013e3180339981.
To implement myocardial first-pass perfusion imaging at 3 Tesla and to evaluate the potential benefit with regard to signal parameters in comparison to 1.5 Tesla using identical sequence settings and an intraindividual comparison.
In 16 volunteers, myocardial first-pass perfusion imaging was performed at 1.5 Tesla (Magnetom Avanto) and 3 Tesla (Magnetom TIM Trio) after injection of 0.05 mmol/kg body weight Gadobutrol using an accelerated saturation recovery TurboFLASH technique (GRAPPA; R=2) at 1.5 and 3 Tesla. Detailed sequence parameters (TR 2.3 milliseconds, TE 0.93 milliseconds, flip angle 15 degrees , bandwidth 780 Hz/px) as well as spatial resolution were kept identical for both field strengths. Artifacts were assessed quantitatively and qualitatively, signal-to-noise ratio (SNR) and contrast enhancement ratio (CER) were calculated from raw data signal intensity-time curves. A linear fit on the upslope was performed for semiquantitative perfusion analysis.
SNR was significantly higher at 3 Tesla than at 1.5 Tesla (35.7+/-11.9 vs. 18.0+/-5.5, P<0.001). CER was significantly greater at 3 Tesla than at 1.5 Tesla (2.2+/-0.9 vs. 1.4+/-0.5, P<0.001). Maximum upslope was significantly higher at 3 Tesla than at 1.5 Tesla (3.3+/-2.4 vs. 2.0+/-1.0, P<0.001). A qualitative examination of all images for artifacts by 2 board-certified radiologists yielded no significant differences between the field strengths.
Three Tesla significantly improves CER and SNR compared with 1.5 Tesla with identical sequence parameters. In addition, the most important semiquantitative perfusion parameter maximum upslope is significantly increased. This may allow for an improvement of spatial resolution and potentially for a better delineation of perfusion defects. However, further studies are necessary to potentially demonstrate a benefit of 3 Tesla perfusion imaging in a clinical setting.
在3特斯拉场强下实施心肌首过灌注成像，并在相同序列设置及个体内比较的情况下，评估相较于1.5特斯拉场强，其在信号参数方面的潜在优势。
对16名志愿者，在注射0.05 mmol/kg体重的钆布醇后，分别于1.5特斯拉（Magnetom Avanto）和3特斯拉（Magnetom TIM Trio）场强下，采用加速饱和恢复快速小角度激发技术（GRAPPA；R = 2）进行心肌首过灌注成像。两种场强下均保持详细的序列参数（重复时间2.3毫秒，回波时间0.93毫秒，翻转角15度，带宽780赫兹/像素）以及空间分辨率相同。对伪影进行定量和定性评估，从原始数据信号强度 - 时间曲线计算信噪比（SNR）和对比增强率（CER）。对上坡段进行线性拟合以进行半定量灌注分析。
3特斯拉场强下的SNR显著高于1.5特斯拉场强（35.7±11.9 vs. 18.0±5.5，P<0.001）。3特斯拉场强下的CER显著大于1.5特斯拉场强（2.2±0.9 vs. 1.4±0.5，P<0.001）。3特斯拉场强下的最大上坡段显著高于1.5特斯拉场强（3.3±2.4 vs. 2.0±1.0，P<0.001）。两位经过委员会认证的放射科医生对所有图像的伪影进行定性检查，结果显示场强之间无显著差异。
与1.5特斯拉场强相比，在相同序列参数下，3特斯拉场强显著提高了CER和SNR。此外，最重要的半定量灌注参数最大上坡段也显著增加。这可能有助于提高空间分辨率，并有可能更好地描绘灌注缺损。然而，需要进一步的研究来潜在地证明3特斯拉灌注成像在临床环境中的优势。
