Background T1w turbo spin echo (TSE) represents a fundamental sequence in magnetic resonance imaging (MRI) protocols investigating the brain. Recent human literature has reported T1w Fluid Attenuated Inversion Recovery's (FLAIR's), superiority to T1wTSE in relation to tissue contrast for grey-to-white matter (GM-WM) and lesion-to-WM, although conflicting results are reported concerning lesion detection.To the author's knowledge, T1wFLAIR has not been investigated in veterinary medicine. The aim of this prospective study was to determine quantitatively and qualitatively which sequence provides better overall better image quality both pre- and post-gadolinium. Results Twenty-eight animals underwent MRI of the brain with T1wTSE and T1wFLAIR sequences performed with equivalent mean acquisition times. Quantitative assessment of the sequences was undertaken using contrast-to-noise (CNR) and signal-to-noise (SNR) ratios from predefined locations. T1wFLAIR provided a better CNR compared to T1wTSE, while T1wTSE provided better SNR due to the higher noise levels of T1wFLAIR images. Qualitative assessment of the sequences was performed using Visual Grading Analysis Scoring (VGAS) for a number of criteria by three observers on two separate occasions. T1wFLAIR performed better for cerebrospinal fluid (CSF) suppression, white-to-grey matter (WM-GM) and white matter-to-CSF (WM-to-CSF) definition in both pre- and post-contrast images whereas the T1wTSE sequence was less affected by noise levels. The individual parameter for overall image quality found no significant difference between the two sequences. However, the composite VGAS favored T1wFLAIR as the preferred sequence. Although case numbers were insufficient for statistical analysis, comparison of the sequences indicates that lesion definition and margination was better in T1wFLAIR pre-contrast images, however post-contrast lesion detection was almost equivalent between sequences with slightly better margination in the T1wTSE sequence. Conclusions T1wFLAIR provides better CNR with better WM-GM and WM-CSF definition both pre- and post-contrast compared to T1wTSE albeit with a higher degree of noise; this was confirmed both quantitatively and qualitatively. Our results also suggest that T1wFLAIR is better for lesion detection and margination pre-contrast administration and sequences are relatively equivocal post-gadolinium administration although further research is required to determine the benefit that inversion recovery sequences make when investigating brain lesions in small animal MRI.

中文翻译：

---

T1wFLAIR 和 T1wTSE 序列在使用高场 MRI 对小动物的大脑进行成像中的比较。

背景 T1w 涡轮自旋回波 (TSE) 代表了研究大脑的磁共振成像 (MRI) 协议中的基本序列。最近的人类文献报道了 T1w 流体衰减反转恢复 (FLAIR)，在灰质到白质 (GM-WM) 和病变到 WM 的组织对比度方面优于 T1wTSE，尽管在病变检测方面报告了相互矛盾的结果。据作者所知，T1wFLAIR 尚未在兽医学中进行过研究。这项前瞻性研究的目的是定量和定性地确定哪种序列在钆前后提供更好的整体图像质量。结果 28 只动物接受了 T1wTSE 和 T1wFLAIR 序列的大脑 MRI，其平均采集时间相同。使用来自预定义位置的对比噪声 (CNR) 和信噪比 (SNR) 对序列进行定量评估。与 T1wTSE 相比，T1wFLAIR 提供了更好的 CNR，而 T1wTSE 提供了更好的 SNR，因为 T1wFLAIR 图像的噪声水平更高。三个观察者在两个不同的场合使用视觉分级分析评分 (VGAS) 对多个标准进行序列的定性评估。T1wFLAIR 在对比前后图像中的脑脊液 (CSF) 抑制、白质到灰质 (WM-GM) 和白质到脑脊液 (WM-to-CSF) 的定义表现更好，而 T1wTSE 序列受噪音水平的影响较小。整体图像质量的单个参数发现两个序列之间没有显着差异。然而，复合VGAS倾向于T1wFLAIR作为首选序列。尽管病例数不足以进行统计分析，但序列的比较表明 T1wFLAIR 对比前图像中的病变定义和边缘更好，但是在 T1wTSE 序列中边缘稍好的序列之间的对比后病变检测几乎相同。结论 与 T1wTSE 相比，T1wFLAIR 提供更好的 CNR，同时具有更好的 WM-GM 和 WM-CSF 清晰度，尽管噪声程度更高；这在数量和质量上都得到了证实。