Department of Endocrinology and Metabolism, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China.
Department of Anatomy, Southern Medical University School of Basic Medical Science, Guangzhou, China.
Clin Endocrinol (Oxf). 2018 May;88(5):637-644. doi: 10.1111/cen.13564. Epub 2018 Mar 6.
Effective management of thyroid-associated ophthalmopathy (TAO) requires precise identification of the disease activity period as it is responsive to immunosuppressive treatment. Quantitative evaluations of orbital soft tissue are useful for analysing disease stages. We aimed to establish a method for orbital soft tissue volume calculation based on magnetic resonance imaging (MRI) data using 3D reconstruction technology. Furthermore, we validated the accuracy and precision of this method and investigated volume differences between patients with TAO and healthy individuals.
Using Mimics software for 3D reconstruction based on orbital MRI data, we quantitatively measured orbital fat volume (FV) and extraocular muscle volume (MV) using a manual phantom, and in patients with TAO and healthy volunteers (n = 10 each). The phantom was made using a combination of butter and chicken muscle and 2 observers measured its volume. Volume calculations were compared to a previously established standard volume. One observer measured a typical TAO case 10 times to calculate intra-observer variability while 3 observers independently measured 10 patients with TAO each to calculate interobserver variability. Orbital soft tissue volumes between 10 patients with TAO and 10 healthy individuals were compared.
The precision of calculations for the phantom between the 2 observers varied from -4.60% to -2.78% for FV and between -4.13% to 0.71% for MV. Mean differences among repetitive calculations were lower than 4%, except during measurement of MV, which was 5.84%. The intraclass correlation coefficient varied from 0.976 to 0.996. FV was 15.53 ± 3.06 mL in patients with TAO and 11.32 ± 1.68 mL(P = .001)in healthy individuals, while MV was 3.19 ± 0.82 mL in patients with TAO and 2.45 ± 0.57 mL(P = .030)in healthy individuals.
This method of calculating orbital soft tissue volumes based on MRI data and 3D reconstruction is both reliable and accurate as it yielded significant differences in tissue volume between patients with TAO and healthy individuals.
甲状腺相关眼病（TAO）的有效管理需要精确识别疾病活动期，因为它对免疫抑制治疗有反应。眼眶软组织的定量评估有助于分析疾病阶段。我们旨在建立一种基于磁共振成像（MRI）数据的 3D 重建技术的眼眶软组织体积计算方法。此外，我们验证了该方法的准确性和精密度，并研究了 TAO 患者与健康个体之间的体积差异。
使用 Mimics 软件基于眼眶 MRI 数据进行 3D 重建，我们使用手动模拟物对眼眶脂肪体积（FV）和眼外肌体积（MV）进行定量测量，分别在 10 例 TAO 患者和健康志愿者中进行测量（每组 10 例）。模拟物由黄油和鸡肉肌肉混合制成，由 2 名观察者进行测量。体积计算与之前建立的标准体积进行比较。一名观察者对 10 例典型 TAO 病例进行了 10 次测量，以计算观察者内变异性，而 3 名观察者分别对 10 例 TAO 患者进行了 10 次测量，以计算观察者间变异性。比较了 10 例 TAO 患者和 10 例健康个体的眼眶软组织体积。
两名观察者之间的模拟物计算精度在 FV 方面从-4.60%到-2.78%不等，在 MV 方面从-4.13%到 0.71%不等。重复测量之间的平均差异低于 4%，除了 MV 的测量值为 5.84%。组内相关系数在 0.976 到 0.996 之间。TAO 患者的 FV 为 15.53 ± 3.06 mL，健康个体的 FV 为 11.32 ± 1.68 mL（P =.001），TAO 患者的 MV 为 3.19 ± 0.82 mL，健康个体的 MV 为 2.45 ± 0.57 mL（P =.030）。
这种基于 MRI 数据和 3D 重建的眼眶软组织体积计算方法既可靠又准确，因为它在 TAO 患者和健康个体之间的组织体积上产生了显著差异。
