Melhem E R, Shakir H, Bakthavachalam S, MacDonald C B, Gira J, Caruthers S D, Jara H
Department of Radiology, Boston University School of Medicine and Medical Center, MA 02118, USA.
AJNR Am J Neuroradiol. 1998 Nov-Dec;19(10):1819-22.
Adult size is achieved in the inner ear labyrinth by approximately 25 weeks' gestation, and minimal variability in age, sex, side, and race is found after birth. In this study, we opted to determine the reproducibility of inner ear volumetric measurements generated from high-resolution heavily T2-weighted 3D fast spin-echo MR images.
The temporal bones of 23 volunteers were imaged using a heavily T2-weighted 3D fast spin-echo MR imaging technique. The images were assessed by a neuroradiologist for the presence of inner ear configurational anomalies and, most important, for complete coverage of the inner ear labyrinth. Subsequently, the volume of the fluid in the inner ear was determined by two observers using a semiautomated segmentation algorithm. The mean, SD, range, and coefficient of variation of fluid volume in the inner ear were calculated. Age-, sex-, and side-related differences in the inner ear volumetric measurements were evaluated using analysis of variance. Interrater consistency in the inner ear volumetric measurements was evaluated by comparing the calculated coefficients of reliability.
Volumetric measurements were available from 46 inner ears in 23 volunteers. The mean volume was 227.8 mm3 (SD, 24.4 mm3), and the coefficient of variation was 10.7%. No age-, sex-, or side-related differences in the inner ear volumetric measurements were found (F ratios were 4.33, 5.04, and 0.26, respectively). Interrater consistency, as assessed by the coefficient of reliability, was 5.3%.
Reproducible volumetric measurements of the inner ear labyrinth can be obtained by applying a semiautomated segmentation algorithm to a heavily T2-weighted 3D fast spin-echo MR imaging data set. These volumetric measurements may help identify patients with congenital sensorineural hearing loss and normal inner ear configuration.
内耳迷路在妊娠约25周时达到成人大小，出生后年龄、性别、侧别和种族的变异性极小。在本研究中，我们选择确定由高分辨率重T2加权3D快速自旋回波MR图像生成的内耳容积测量的可重复性。
使用重T2加权3D快速自旋回波MR成像技术对23名志愿者的颞骨进行成像。神经放射科医生评估图像是否存在内耳结构异常，最重要的是评估内耳迷路的完全覆盖情况。随后，两名观察者使用半自动分割算法确定内耳中液体的体积。计算内耳液体体积的平均值、标准差、范围和变异系数。使用方差分析评估内耳容积测量中与年龄、性别和侧别相关的差异。通过比较计算出的可靠性系数来评估内耳容积测量中的评分者间一致性。
23名志愿者的46只内耳可获得容积测量值。平均体积为227.8 mm³（标准差为24.4 mm³），变异系数为10.7%。在内耳容积测量中未发现与年龄、性别或侧别相关的差异（F值分别为4.33、5.04和0.26）。通过可靠性系数评估的评分者间一致性为5.3%。
通过将半自动分割算法应用于重T2加权3D快速自旋回波MR成像数据集，可以获得可重复的内耳迷路容积测量值。这些容积测量可能有助于识别先天性感音神经性听力损失且内耳结构正常的患者。
