眼外肌病变的MRI表现

目的探讨眼外肌病变的MRI表现,提高对其诊断和鉴别诊断的能力。资料与方法回顾性分析151例眶部疾病累及眼外肌患者的MRI表现。结果129例病变仅累及眼外肌肌腹（其中Graves眼病123例）,22例病变同时累及肌腱和肌腹（其中非特异性眶部肌炎7例,无Graves眼病病例）。77.8%的非特异性眶部肌炎仅累及单块肌肉,88.6%的Graves眼病是多块肌肉受累,眶部淋巴瘤、炎性假瘤和蜂窝织炎均是多肌肉受累。大多数Graves眼病及非特异性眶部肌炎均表现为中等程度大小、长形、边缘清楚的眼外肌病变,而肿瘤侵犯、眶部炎性假瘤和蜂窝织炎所致眼外肌病变则表现为不规则形、边缘不清。39例慢性期Graves眼病所致的眼外肌病变发生脂肪变性。61例急性期Graves眼病在T2WI上增粗的眼外肌表现为高信号,其T2值延长,均值为123ms（100-174ms）。结论眼外肌病变的位置、形态及其信号特征在MRI诊断和鉴别诊断中起重要作用。     

定量眼眶冠状位CT测量在甲状腺相关眼病中的应用

目的 探讨定量冠状位CT检查在Graves眼病诊断中的应用价值.方法 分别测量50例正常者和50例Graves眼病者的眼外肌的最大截面积、短径和长径,并计算每条眼外肌的R值.结果 50例Graves眼病患者,共228条眼外肌增粗,以下直肌(30.3%)和内直肌(23.2%)最常见,其次为上直肌(19.7%),外直肌(13.6%)和上斜肌(13.4%),其平均最大截面积(70.21 mm2、56.93 mm2、64.06 mm2、58.51 mm2、20.65 mm2)和R值(0.61、0.55、0.61、0.50、0.52)明显大于正常组的平均最大截面积(27.72 mm2、 27.07 mm2、26.93 mm2、36.74 mm2、9.42 mm2)和R值(0.41、0.35、0.60、0.34、0.44),Graves组和正常组之间差异有统计学意义(P＜0.01).结论 定量冠状位CT检查特别是R值的测量可以准确判断眼外肌的增厚,有助于Graves眼病的诊断.     

甲状腺相关性眼病CT影像学定量分析

目的 探讨甲状腺相关性眼病(TAO)眼外肌肥厚及其他结构异常的CT定量价值.资料与方法 回顾性分析36例TAO患者的CT影像资料,并选取16名健康志愿者进行对照研究.36例TAO患者和16名健康志愿者均行横断位和冠状位检查,层厚和层距2 mm.比较TAO组与对照组之间眼外肌最大横截面积以及眼外直肌肌腹与肌腱(短径)及其比值的范围,所得数据的比较采用t检验.结果 病变组与对照组比较,眼外肌最大横截面积差异有统计学意义(P<0.01),病变组均大于对照组;下直肌增大幅度最大(t=15.74),其次为内直肌.眼外直肌肌腱与肌腹厚度(短径)及其比值,肌腱增粗在病变组与对照组比较中差异有统计学意义(P<0.01),病变组均大于对照组.眼外直肌肌腱与肌腹比值>0.5,提示肌腱受累.结论 TAO多伴有眼外肌肌腹肥大、肌腱受累和眼眶脂肪容积改变,CT影像学定量分析有助于临床诊断.     

Graves眼病的MRI诊断（附44例分析）

目的：研究Graves眼病的磁共振成像（MRI）表现,探讨其在临床治疗中的应用价值。方法：回顾性分析44例Graves眼病的MRI影像资料。结果：MRI显示眼外肌肿胀44例,其中眼外肌水肿40例,脂肪变性6例,眼外肌纤维化5例。眼球突出40例,提上睑肌肥厚37例,泪腺肿大5例,眼上静脉扩张6例,视神经增粗3例。结论：MRI不仅能显示Graves眼病的形态学改变,并能显示眼外肌的病理变化。其中做为治疗中是否用抗炎药物的依据。     

MRT1-mapping技术在甲状腺相关眼病临床分期中的初步探索

【摘要】目的：探讨T1-mapping技术在甲状腺相关眼病（TAO）临床分期中的应用价值。方法：回顾性分析50例TAO患者的临床和影像资料,测量每例患者4条眼外肌中信号强度最高（“热点”）和最低区域（“冷点”）的T1弛豫时间（T1RT）,比较活动期组和非活动期组之间热点和冷点T1RT值的差异,并采用受试者工作特征曲线评估T1RT在TAO分期中的诊断效能。结果：活动期组眼外肌T1RT的冷点值显著高于非活动期组（P<0.001）,而两组间眼外肌的T1RT热点值的差异无统计学意义（P=0.122）。T1RT冷点值与临床活动性评分呈正相关（r=0.501,P<0.001）。以T1RT冷点值≥1000ms判断TAO处于活动期的效能最优（曲线下面积为0.815,敏感度为80.6%,特异度为71.1%）。结论：T1-mapping技术在甲状腺相关眼病分期中具有临床应用价值,眼外肌T1RT冷点值可作为预测甲状腺相关眼病分期的指标。     

基于3T-MR图像泪腺定量测量在Graves眼病诊断及分期中的价值

【摘要】目的：探讨3T-MRI泪腺定量测量在Graves眼病（GO）诊断及分期中的价值。方法：对33例Graves眼病患者和24例健康人（对照组）行3.0TMR眼眶扫描,分别在横轴面及冠状面图像上测量泪腺的长径、短径、截面积,计算泪腺的体积、泪腺与同侧颞肌的信号强度比（SIR）。比较泪腺各定量参数的组间差异,采用受试者工作特征曲线（ROC）分析组间比较有差异的泪腺定量参数对GO的诊断效能。结果：GO组泪腺各定量测量参数除冠状面长径外,均明显大于正常对照组（P<0.05）,以横轴面及冠状面短径增大最显著。与GO非活动期组比较,活动期组仅泪腺 颞肌SIR明显增大（P=0.001）。以泪腺 颞肌SIR≥2.57指导GO分期,可获得最优的诊断价值（AUC=0.711,敏感度57.7%,特异度77.5%）。结论：3T-MRI泪腺定量测量可辅助GO的诊断及临床分期。     

Graves病患者眼眶CT定量

Graves眼病的典型CT征有:眼外肌肥大、突眼、眶内脂肪体积增加、视神经拉长、眶内脂肪脱出。眼外肌作为该病眶内主要受累组织,它的体积和形状可用CT定量和客观的测量。为了确定正常眼外肌密度的CT值和定量估计Graves病患者眼外肌的密度、体积及眼球的位置,作者临床检查了100例无眼眶和甲状腺疾患的副鼻窦疾病病人的200个正常眼眶和87例经临床和实验室检查诊断为Graves病患者的174个眼眶(均未经眶内手术和放疗),用CT评估了眼外肌的密度、体积,眼球位置和视神经复合     

帕金森病脑内铁沉积的SWI定量研究

目的：通过比较帕金森病（PD）患者与正常对照组脑内多个结构的T2＊值,探讨PD的发病和进展与脑内铁沉积的关系。方法：采用3TMR系统对40例原发性PD患者及40例年龄、性别相匹配的健康志愿者（正常对照组）进行常规序列及SWI序列扫描。按Hoehn-Yahr分级量表将24例单侧症状PD患者作为PD-1组,16例双侧症状患者作为PD-2组。经后处理在T2＊图上分别手动测量双侧黑质致密带、黑质网状带、红核、苍白球、壳核、尾状核头、丘脑和额叶白质区共8个部位的T2＊值,并将所获得数据进行统计分析。结果：①PD-1组症状侧与正常对照组同侧在黑质致密部的T2＊值差异有统计学意义（P〈0．05）,在其它7个部位的T2＊值差异无统计学意义（P〉0．05）;②PD-1组症状侧与正常对照组对侧在黑质致密部的T2＊值差异有高度统计学意义（P〈0．01）,在黑质网状部的T2＊值差异有统计学意义（P〈0．05）,在其它6个部位的T2＊值差异无统计学意义（P〉0．05）;③PD-1组症状对侧与正常对照组对侧在黑质致密部、红核的T2＊值差异有统计学意义（P〈0．05）,而在其它部位的T2＊值差异无统计学意义（P〉0．05）;④PD-1组症状对侧与正常对照组同侧的各兴趣区T2＊值之间差异无统计学意义（P〉0．05）;⑤PD-1组和正常对照组各兴趣区的双侧T2＊值的差异均无统计学意义（P〉0．05）;⑥PD-2组与PD-1组和正常对照组间各兴趣区T2＊值差异均无统计学意义（P〉0．05）。结论：在PD的亚临床期脑内即有铁的异常沉积;局部铁含量的增加与单侧症状PD的发病有相关性,但与病情的严重程度无显著相关性;PD铁异常沉积的部位包括黑质致密部、黑质网状部、红核。     

Hoffa病与髌骨运动轨迹异常相关性的MRI研究

目的：探讨Hoffa病与髌骨运动轨迹异常的相关性。方法：回顾性分析46例经MRI证实为髌下脂肪垫水肿的Hoffa病患者（病例组）及28例健康体检者（对照组）的MRI及临床资料。病例组中11例行关节镜治疗及病理学检查。在MRI图像上测量5个髌骨运动轨迹参数,包括股骨滑车深度、股骨滑车与胫骨结节的水平距离（TTTG）、髌骨外移度、外侧髌股角（PFA）和InsallSalvati指数。对这5个指标在病例组和正常组问的差异进行统计学分析。结果：Hoffa病的髌下脂肪垫水肿在脂肪抑制T2WI及PDWI序列上显示清晰,均呈高信号改变。病例组及对照组股骨滑车与胫骨结节的距离（TTTG）、外侧髌股角（PFA）和Insall-Salvati指数间的差异有统计学意义（Z值分别为-2．523、-2．261和-2．812,P值均〈0．05）,两组间滑车深度及髌骨外移度的差异无统计学意义（z值分别为-1．025和-0．111,P值均〉0．05）。病例组内出现髌骨外移度（〉3mm）、外侧髌股角（PFA≤0°）和Insall-Salvati指数（〉1．2）异常者较对照组多,两组间差异有统计学意义（X^2值分别为6．917、5．572和9．582,P值均〈0．05）。结论：Hoffa病的主要MRI表现为髌下脂肪垫水肿,MRI是本病的首选检查方法;Hoffa病与髌骨运动轨迹异常间有相关性。     

8通道360度全景眼表面线圈在3.0T MR成像中的应用

【摘要】目的：探讨8通道360度全景眼表面线圈在眼部3.0T MR成像中的应用价值。方法：将符合入组标准的94例患者随机分为头线圈组和眼表面线圈组，每例患者依次行平扫FSE T1WI、FRFSE T2WI及常规增强扫描。由两位有经验的医师分别在平扫图像上评估眼球、眼外肌、泪腺、视神经和血管、颞肌、眶隔及病灶，对图像质量进行主观评分，计算各结构的信噪比（SNR），并比较两组间的差异。结果：在平扫FSE T1WI和FRFSE T2WI上眼表面线圈组的眼球、眼外肌前1/2、视神经前1/2、泪腺、颞肌及病变的SNR显著高于头线圈组（P值均＜0.05），而眼外肌后1/2、视神经后1/2的SNR在两组间的差异无统计学意义（P值均＞0.05）。眼表面线圈组中平扫FSE T1WI、FRFSE T2WI图像上眼球、眼外肌、视神经及血管、颞肌、泪腺、眶隔及病变的显示效果的主观评分均显著高于头线圈组（P值均＜0.05）。两位医师对各眼部结构图像质量的主观评分结果具有较高的一致性（Kappa值为0.621～0.950）。结论：应用8通道360度全景眼表面线圈能更清晰地显示眼部的解剖结构和病变特征，并且较常规头部线圈的图像质量更高，可作为眼部3.0T MR检查的首选配置。     

Graves ophthalmopathy: role of MR imaging in radiation therapy

Twenty-three patients with Graves ophthalmopathy who underwent radiation therapy were monitored by means of magnetic resonance (MR) imaging. T2 relaxation times of extraocular muscles and orbital fat, areas of extraocular muscles, and degree of exophthalmos were measured by means of MR imaging at the beginning, at the end, and 3 months after completion of radiation therapy. As a result, patients with primarily elevated T2 times of extraocular muscles showed a better therapy response regarding muscle thickening than patients with primarily normal T2 times. Elevated T2 times, which probably represent acute inflammatory changes, were markedly decreased at the end of therapy. Therefore, quantitative MR imaging favors the choice of anti-inflammatory therapy regimens in patients with elevated T2 times of extraocular muscles. However, the clinical response (activity scores) to the low-dose treatment protocol that was used did not correlate well with primarily elevated T2 times. Furthermore, T2 times increased again after cessation of therapy. Whether a higher radiation dose or a different fractionation scheme leads to better results must be clarified by means of further study.     

Exophthalmos caused by excessive fat: CT volumetric analysis and differential diagnosis

CT has proven to be excellent in identifying orbital pathology responsible for proptosis. Occasionally, no discrete mass or extraocular muscle enlargement to explain the exophthalmos is found, only an appearance suggestive of an abnormal increase in orbital fat volume. Fifteen patients were studied with proptosis apparently resulting from increased orbital fat. Clinical follow-up revealed that four of them had Graves orbitopathy, unilateral in one; two had Cushing disease/syndrome; and nine were obese without endocrinopathy. The orbital volume and percentage orbital fat volume were measured by CT software analysis in these patients and in a control group of 16 patients without proptosis. Measurements of proptosis and thickness of the scalp fat pad at the inion level were also performed. Significantly greater values for orbital fat volume, percentage fat volume, and proptosis were found in the proptosis group compared with the control group. There was excellent correlation between proptosis and percentage fat volume, supporting the contention that increased orbital fat is responsible for the proptosis. The thickness of the scalp fat pad at the inion level was significantly greater in obese and Cushing patients than in control subjects, but the thickness was not significantly greater in Graves patients than in controls. Proptosis and inion fat were well correlated (r = 0.74) in the control and obese patients, which suggests a relation between general body fat and orbital fat volume.     

Extraocular muscle quantification using mathematical morphology: a semi-automatic method for analyzing muscle enlargement in orbital diseases.

Mathematical morphology was used to quantify the dimensions of the human extraocular muscles in computed tomography orbital scans. Coronal images of 28 patients with Graves orbitopathy and 5 controls (218 orbital scans) were analyzed with an algorithm for extraocular muscle segmentation. The results showed that measurements of extraocular muscle area obtained with semi-automatic segmentation are highly correlated with manual tracing and provides a simple method to quantify orbital structures including the extraocular muscles.     

Quantitative CT of the orbit in Graves' disease

In order to determine the value of quantitative CT of the orbit in patients with Graves' disease, we clinically examined 174 orbits of 87 patients with Graves' disease and evaluated them by CT in respect to the density and size of the extraocular muscles, the globe position and the width of the optic nerve-sheath complex. We also determined the normal ranges for density of extraocular muscles in 200 normal orbits of 100 patients for comparison. Normal ranges for the density of extraocular muscles were (mean +/- 2 SD) medial rectus, 28-63 HU; lateral rectus, 24-78 HU; inferior rectus, 20-64 HU; superior muscle group, 28-62 HU. 51 of 77 (66%) patients with Graves' disease had extraocular muscle density changes. Some extraocular muscles showed fatty infiltration on CT. 50 of 87 (57%) patients had at least one enlarged extraocular muscle, 47 (54%) patients had exophthalmos and 59 (68%) patients had either exophthalmos and/or extraocular muscle enlargement. A diagnosis of Graves' ophthalmopathy was made in 69 of 87 (79%) patients using CT and in 50 (57%) patients by clinical examination. We conclude that quantitative CT imaging of the orbit with evaluation of the size and density values of extraocular muscles and the globe position may be very helpful in detecting ophthalmopathy in patients with Graves' disease.     

眶部肌锥外间隙非霍奇金淋巴瘤的高分辨率MRI表现

目的探讨眶部肌锥外间隙非霍奇金淋巴瘤(NHL)的高分辨率MR(HRMR)成像特征。方法回顾性分析16例经病理诊断明确的眶部肌锥外间隙NHL病灶的位置、数目、形态、大小、MRI信号及其对邻近结构侵犯等。MR扫描采用15TMR扫描机,眼眶部表面线圈,SE及快速SE(FSE)序列常规横轴面或冠状面及斜矢状面扫描,全部病例行脂肪抑制技术。全部病例均行增强扫描及HRMRI检查。结果16例中的13例病灶位于肌锥外间隙的前上份,紧靠眶隔的后方,呈不规则的长条状铸型改变;其余3例为弥漫性病变,累及眶部肌锥外间隙,呈不规则形。11个病灶的体积>3cm3,4个病灶的体积为中等大小(1~3cm3),只有1例病灶<1cm3。13例病灶边缘不清晰并浸润眼外肌但不推移眼外肌;7例浸润眼球壁,仅3例眼球突出,2例弥漫性病变者伴有骨质破坏。与肌肉比较,所有16例病灶T1WI均为等信号,T2WI表现为高信号13例,等信号3例;所有16例病灶均有强化,15例为均匀强化,10例为明显强化。结论眶部肌锥外间隙NHL的HRMRI表现具有一定的特征性,表现为铸型生长、位于肌锥外间隙的前份,紧靠眶隔的后方、病灶边缘欠清晰并浸润,但不推移眼外肌,T1WI信号等于肌肉、T2WI信号高于肌肉、增强扫描病灶呈明显强化。眶部肌锥外间隙NHL的HRMR影像学特征有助于临床与其他眶部占位相鉴别。     

Radiation therapy of Graves' ophthalmopathy]

During the decade from 1978 to 1987, 20 patients with Graves' ophthalmopathy were treated with irradiation of 2000 cGy to the orbital tissue. We examined the effects of the therapy on 17 such patients. Exophthalmos tended to decrease. When the degree of deviation of the exophthalmic eye was small, the effect of therapy tended to be better than when it was large. Two cases that showed an increase in retrobulbar fatty tissue without thickening of the extraocular muscles did not respond as well as those that had thickening of the extraocular muscles. Diplopia tended to improve both subjectively and objectively. Ocular movement improved in 11 of the 17 patients. There were no serious radiation injuries after the radiation therapy, except for some transient swelling of the eyelid.     

Diagnostic accuracy of short-time inversion recovery sequence in Graves’ ophthalmopathy before and after prednisone treatment

Introduction

In Graves’ Ophthalmopathy, it is important to distinguish active inflammatory phase, responsive to immunosuppressive treatment, from fibrotic unresponsive inactive one. The purpose of this study is, first, to identify the relevant orbital magnetic resonance imaging signal intensities before treatment, so to classify patients according to their clinical activity score (CAS), discriminating inactive (CAS?<?3) from active Graves’ Ophthalmopathy (GO) (CAS?>?3) subjects and, second, to follow post-steroid treatment disease.

Methods

An observational study was executed on 32 GO consecutive patients in different phases of disease, based on clinical and orbital Magnetic Resonance Imaging parameters, compared to 32 healthy volunteers. Orbital Magnetic Resonance Imaging was performed on a 1.5 tesla Magnetic Resonance Unit by an experienced neuroradiologist blinded to the clinical examinations.

Results

In pre-therapy patients, compared to controls, a medial rectus muscle statistically significant signal intensity ratio (SIR) in short-time inversion recovery (STIR) (long TR/TE) sequence was found, as well as when comparing patients before and after treatment, both medial and inferior rectus muscle SIR resulted significantly statistically different in STIR. These increased outcomes explain the inflammation oedematous phase of disease, moreover after steroid administration, compared to controls; patients presented lack of that statistically significant difference, thus suggesting treatment effectiveness.

Conclusion

In our study, we proved STIR signal intensities increase in inflammation oedematous phase, confirming STIR sequence to define active phase of disease with more sensibility and reproducibility than CAS alone and to evaluate post-therapy involvement.     

Graves' ophthalmopathy: the role of diffusion-weighted imaging in detecting involvement of extraocular muscles in early period of disease

Objective:

To evaluate involvement of the extraocular muscle (EOM) using diffusion-weighted imaging (DWI), to determine whether there is correlation with conventional orbital MRI and apparent diffusion coefficient (ADC) values in patients with Graves'' ophthalmopathy (GO).

Methods:

35 patients known clinically with GO and 21 healthy controls were studied. Patients were assessed with clinical activity scores. All subjects underwent conventional MRI and DWI study. Involvement of the EOM was evaluated. The patients were classified as involved or uninvolved on orbital MRI and their ADC values in DWI compared.

Results:

There was significant difference in the mean ADC value of all the EOMs in patients vs controls. The ADC values of all the EOMs were higher in patients. There were significant differences in ADC values between uninvolved muscles on conventional MRI and controls for the MR, SR and LR. There was no significant difference in ADC value between the two groups when considering the IR. ADC values of medial, lateral and superior rectus muscles were increased.

Conclusion:

Increased ADC values of the EOM in patients with GO suggest that EOM damage begins at a very early stage before being detected on routine orbital MRI. The routine MRI with DWI sequence will be a useful adjunct in the selection of a group of patients most likely to benefit from early treatment.

Advances in knowledge:

This study can help to evaluate the involvement of GO in early period with MRI added DWI.Graves'' ophthalmopathy (GO) is a disorder frequently associated with autoimmune thyroid diseases that involve the retro-ocular space. This disease leads to oedema and swelling resulting in proptosis and diplopia.^1,2 It is clinically relevant in 40–50% of patients with Graves'' disease and in 2–5% of patients with immune thyroiditis.³GO is usually bilateral, but it can be asymmetric or unilateral in 15% of patients.³ The exact pathogenesis of GO remains unclear. Whatever the mechanism, ultimately, the connective tissues are extensively remodelled with the enlargement of the extraocular muscles (EOMs) and orbital adipose tissues.^4,5 Patients with GO usually present symmetric, multiple EOM enlargement in both orbits, although asymmetric muscle involvement can occur. However, true unilateral orbital involvement is uncommon, occurring in only 6–10% of patients.⁶ The muscles most frequently affected are the medial and inferior rectus muscles.⁶Orbital conventional MRI is required to avoid unnecessary decompression surgery in unclear or asymmetric proptosis, in suspected optic neuropathy. MRI can detect not only the presence or absence of swollen tissue but also objectively quantify the activity of inflammation.⁷ Diffusion-weighted imaging (DWI) provides qualitative and quantitative functional information concerning the microscopic movements of water at the cellular level. It allows a non-invasive characterization of microstructural changes. DWI has become a valuable imaging method in the evaluation of certain diseases such as head and neck, liver or kidney lesions.Recently, there has been one study on evaluation of GO using MRI with DWI in literature.⁸ The goal of our study was to assess whether differences between involvement on conventional orbital MRI and apparent diffusion coefficient (ADC) values for each EOM in patients with GO compared with those in healthy controls, and to investigate effectiveness of ADC values in diagnosis of involvement of EOM.     

Unilateral endocrine exophthalmos. Diagnostic problems in association with computed tomography

Summary Swollen orbital extraocular muscles may mimic an orbital apex tumor on computed tomography. In five of our patients, in spite of highly suggestive findings on CT scanning, indicating the presence of an orbital apex lesion, the correct diagnosis proved to be endocrine exophthalmos. The value of complementary CT projections and of orbital ultrasonography to assist in the differential diagnosis is discussed, and the additional contribution of orbital phlebography for the confirmation of lesions in the orbital apex is emphasized.