Yokoyama Naokata, Nagataki Shigenobu, Uetani Masataka, Ashizawa Kiyoto, Eguchi Katsumi
Department of Internal Medicine, Oita National Hospital, Japan.
Thyroid. 2002 Mar;12(3):223-7. doi: 10.1089/105072502753600179.
Two different phases in disease activity are observed during the clinical course of thyroid-associated ophthalmopathy (TAO). The assessment of disease activity is important for predicting the outcome of medical management because medical treatment can be effective in the active stage. The aim of this study was to investigate whether magnetic resonance imaging (MRI) could assess the disease activity in TAO. To investigate the relation between MRI-T2 signal intensity (SI) and extraocular muscle (EOM) size, 11 patients with TAO were evaluated. EOM sizes (enlargement, volume) were measured by MRI-T1 image. T2-SI of EOM was expressed as a percentage of temporal muscle. The reduction in T2-SI was significantly positively correlated with that of EOM enlargement after treatment. Additionally, T2-SI in pretreatment showed a significant correlation with reduction in EOM volume for therapeutic effect, which indicates T2-SI in pretreatment can be one of the reliable parameters for predicting the therapeutic outcome of treatment. To investigate whether MRI-T2 pattern could predict the reversibility of diplopia, 28 patients with Graves' disease with or without ophthalmopathy were evaluated. Patients with TAO with reversible diplopia showed an uniform T2 pattern in enlarged EOM. However, in patients with irreversible diplopia caused by the mechanical limitation of EOM, MRI-T2 image showed no uniformity with a partial appearance of low T2-SI. The partial low T2-SI may indicate the progress of inactive (fibrotic) change in EOM after active (inflammatory) change. In conclusion, MRI is a useful tool for detection not only of EOM enlargement, but also disease activity in TAO. MRI-T2 SI and pattern can predict the outcome of medical management in TAO.
在甲状腺相关性眼病（TAO）的临床病程中观察到疾病活动的两个不同阶段。疾病活动度的评估对于预测药物治疗的结果很重要，因为药物治疗在活动期可能有效。本研究的目的是调查磁共振成像（MRI）是否可以评估TAO的疾病活动度。为了研究MRI-T2信号强度（SI）与眼外肌（EOM）大小之间的关系，对11例TAO患者进行了评估。通过MRI-T1图像测量EOM大小（增大、体积）。EOM的T2-SI表示为颞肌的百分比。治疗后T2-SI的降低与EOM增大的降低显著正相关。此外，治疗前的T2-SI与EOM体积减少的治疗效果显著相关，这表明治疗前的T2-SI可以作为预测治疗效果的可靠参数之一。为了研究MRI-T2模式是否可以预测复视的可逆性，对28例患有或未患有眼病的格雷夫斯病患者进行了评估。TAO伴有可逆性复视的患者在增大的EOM中表现出均匀的T2模式。然而，在由EOM机械性限制导致的不可逆复视患者中，MRI-T2图像显示不均匀，部分出现低T2-SI。部分低T2-SI可能表明活动期（炎症）改变后EOM中不活动（纤维化）改变的进展。总之，MRI不仅是检测EOM增大的有用工具，也是检测TAO疾病活动度的有用工具。MRI-T2 SI和模式可以预测TAO的药物治疗结果。
