School of Medicine, Xiamen University, Xiamen, Fujian, China.
Department of Surgery Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
J Voice. 2023 Mar;37(2):187-193. doi: 10.1016/j.jvoice.2020.12.016. Epub 2020 Dec 31.
The diffusion characteristics of water molecules were measured in the vocal folds of canines exhibiting unilateral vocal fold paralysis and unilateral cricoarytenoid joint dislocation. These characteristics were used in conjunction with a histological examination of the microstructural changes of vocal fold muscle fibers to explore the feasibility of diffusion tensor imaging (DTI) in distinguishing unilateral vocal fold paralysis and unilateral cricoarytenoid joint dislocation as well as evaluating microstructural changes.
Ten beagles were randomly divided into three groups: four in the unilateral vocal fold paralysis group, four in the unilateral cricoarytenoid joint dislocation group, and two in the normal group. Unilateral recurrent laryngeal nerve resection was performed in the vocal fold paralysis group. Unilateral cricoarytenoid joint dislocation surgery was performed in the dislocation group. No intervention was performed in the normal group. Four months postintervention, the larynges were excised and put into a magnetic resonance imaging (MRI) system (9.4T BioSpec MRI, Bruker, German) for scanning, followed by an analysis of diffusion parameters among the different groups for statistical significance. After MRI scanning, the vocal folds were cut into sections, stained with hematoxylin and eosin, and scanned digitally. The mean cross-sectional area of muscle fibers, and the mean diameter of muscle fibers in the vocal folds were calculated by target detection and extraction technology. Mean values of each measurement were used to compare the differences among the three groups. Pearson correlation analysis was performed on the DTI parameters and the results from histological section extraction.
The paralysis group had significantly higher Fractional Anisotropy (FA) compared to the dislocation group and normal group (P = 0.004). The paralysis group also had a significantly lower Tensor Trace value compared to the dislocation group and normal group (P = 0.000). The average cross-sectional area of vocal fold muscle fibers in the paralysis group was significantly smaller than the dislocation group and normal group (P = 0.000). Pearson correlation analysis yielded values of, r = -0.785, P = 0.01 between the average cross-sectional area of vocal muscle fibers and FA, and values of r = 0.881, P = 0.00 between Tensor Trace and the average cross-sectional area of vocal muscle.
FA and Tensor Trace can be used as effective parameters to reflect the changes of microstructure in vocal fold paralysis and cricoarytenoid joint dislocation. DTI is an objective and quantitative method to effectively evaluate unilateral vocal fold paralysis and unilateral cricoarytenoid joint dislocation, also capable of noninvasively evaluating vocal fold muscle fiber microstructure.
测量单侧声带麻痹和单侧环杓关节脱位犬的声带水分子扩散特性。结合声带肌纤维微观结构变化的组织学检查，探讨扩散张量成像（DTI）在鉴别单侧声带麻痹和单侧环杓关节脱位以及评估微观结构变化方面的可行性。
10 只比格犬随机分为三组：单侧声带麻痹组 4 只，单侧环杓关节脱位组 4 只，正常组 2 只。声带麻痹组行单侧喉返神经切除术，脱位组行单侧环杓关节脱位术，正常组不干预。术后 4 个月，切除喉头置于磁共振成像（MRI）系统（9.4T BioSpec MRI，Bruker，德国）进行扫描，然后对不同组间的扩散参数进行统计分析。MRI 扫描后，将声带切成切片，苏木精和伊红染色，数字扫描。采用目标检测和提取技术计算声带肌纤维的平均横截面积和肌纤维的平均直径。采用均值比较三组间差异。对 DTI 参数与组织学切片提取结果进行 Pearson 相关性分析。
麻痹组的各向异性分数（FA）明显高于脱位组和正常组（P=0.004）。麻痹组的张力量值也明显低于脱位组和正常组（P=0.000）。麻痹组声带肌纤维的平均横截面积明显小于脱位组和正常组（P=0.000）。Pearson 相关性分析得出，FA 与平均声带肌纤维横截面积的 r 值为-0.785，P=0.01；张力量值与平均声带肌纤维横截面积的 r 值为 0.881，P=0.00。
FA 和张量迹可以作为有效参数，反映声带麻痹和环杓关节脱位的微观结构变化。DTI 是一种客观、定量的方法，可有效评估单侧声带麻痹和单侧环杓关节脱位，还可无创评估声带肌纤维的微观结构。
