Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Magn Reson Med Sci. 2010;9(1):17-22. doi: 10.2463/mrms.9.17.
T(1)-shortening of labyrinthine fluid on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) has been reported in many inner ear disorders. Although semi-quantitative assessment by simple signal intensity ratio between cochlear fluid and brain tissue has been tried, its feasibility using a multi-channel phased-array head coil with an inherently inhomogenous sensitivity distribution has not been fully evaluated. We evaluated the feasibility of measuring simple signal intensity ratio by correlating rapid T(1) measurements using an inversion time (TI) scout sequence.
We evaluated 10 patients with Meniere's disease and 4 patients with sudden deafness. Nine of the patients with Meniere's disease received a unilateral intratympanic injection of Gd-DTPA; the tenth patient received bilateral injections. The 4 patients with sudden deafness received a double-dose intravenous injection. Magnetic resonance (MR) images were obtained 24 hours after intratympanic injections and 4 hours after intravenous injections at 3 tesla using a 32-channel head coil. We measured the ratio (CM ratio) between the signal intensity of the perilymph in the cochlea (C) and that of the medulla oblongata (M) and correlated it with the null-point inversion time (TI(null)) obtained with the TI scout sequence. The TI scout consisted of 85 images obtained with TI values between 132.5 and 3087.5 ms at increments of 37.5 ms.
The correlation coefficient between TI(null) and the natural logarithm of the CM ratio was -0.88 (P<0.01). There was significant negative linear correlation.
Measurement of the simple signal intensity ratio between the cochlea and the medulla can be used for semi-quantitative analysis of 3D-FLAIR. The results of this study may facilitate clinical research of inner-ear disease using 3D-FLAIR.
T1 缩短在许多内耳疾病中已在 3 维液体衰减反转恢复（3D-FLAIR）的实验室流体报告。虽然已经尝试了通过耳蜗流体和脑组织之间的简单信号强度比的半定量评估，但其使用具有固有不均匀灵敏度分布的多通道相控阵头部线圈的可行性尚未得到充分评估。我们通过使用反转时间（TI）侦察序列相关的快速 T1 测量来评估测量简单信号强度比的可行性。
我们评估了 10 例梅尼埃病患者和 4 例突发性聋患者。9 例梅尼埃病患者接受单侧鼓室内注射 Gd-DTPA；第十例患者接受双侧注射。4 例突发性聋患者接受双倍静脉注射。在 3 特斯拉使用 32 通道头部线圈，在鼓室内注射后 24 小时和静脉注射后 4 小时获得磁共振（MR）图像。我们测量了耳蜗（C）的外淋巴信号强度与延髓（M）的信号强度之比（CM 比），并将其与 TI 侦察序列获得的零值反转时间（TI(null)）相关联。TI 侦察由在 132.5 到 3087.5 毫秒之间的 TI 值的 85 个图像组成，增量为 37.5 毫秒。
TI(null)与 CM 比的自然对数之间的相关系数为-0.88（P<0.01）。存在显著的负线性相关。
耳蜗和延髓之间的简单信号强度比的测量可用于 3D-FLAIR 的半定量分析。本研究的结果可能有助于使用 3D-FLAIR 进行内耳疾病的临床研究。
