MRI对脊髓亚急性联合变性的诊断价值

目的 评价ＭＲＩ诊断脊髓亚急性联合变性（ＳＣＤ）的价值。方法 ７例维生素Ｂ１２缺乏而临床怀疑ＳＣＤ的患者进行了ＭＲ扫描。扫描包括矢状面Ｔ１ＷＩ和矢状面、轴面Ｔ２ＷＩ,其中４例行钇喷替酸葡甲胺（Ｇｄ－ＤＴＰＡ）增强扫描,４例于治疗后行ＭＲＩ复查结果所有病例的Ｔ２ＷＩ均显示。戏髓或胸髓后索高倍病灶,有４例同时出现侧索病灶,Ｔ１ＷＩ未见异常,Ｇｄ－ＤＴＰＡ增强鞠强化。有４例在维生素Ｂ１２治疗后半年及１年     

Shy—Drager综合征与纹状体黑质变性MRI—病理对照研究

目的：探讨Ｓｈｙ－Ｄｒａｇｅｒ综合征（ＳＤＳ）、纹状体黑质变性（ＳＮＤ）ＭＲＩ异常信号与病理改变的关系。材料与方法：分别对ＳＤＳ、ＳＮＤ各１例脑标本进行ＭＲＩ扫描与病理对照研究。使用自旋回波（ＳＥ）序列扫描，对照ＭＲＩ图像所显示的异常信号行标本大体及镜下观察。结果：ＳＤＳＭＲＩ显示壳核对称性短Ｔ２低信号，病理改变为神经细胞数量减少，铁元素过度沉积；ＳＮＤＭＲＩ显示双侧壳核等Ｔ１、长Ｔ２信号，病理证实为神经细胞数量减少并坏死，胶质增生、毛细血管增多、脂褐素增多。结论：ＭＲＩ壳核异常信号的显示对生前诊断ＳＤＳ与ＳＮＤ具有重要参考价值     

MRI与CT对颅颈移行区肿瘤的诊断价值评估：附16例分析

本文旨在评价ＭＲＩ与ＣＴ对颅颈移行区病变的诊断价值，共１６例分析，包括斜坡脊索瘤５例，小脑下蚓部肿瘤２１例，延髓肿瘤４例，上颈段脊髓肿瘤５例。患者均作ＭＲＩ平扫，采用ＳＥ系列，Ｔ１Ｗ（ＴＲ５００／ＴＥ３０ｍｓ）、Ｔ２Ｗ（ＴＲ１８００／ＴＥ９０ｍｓ）和质子密度像（ＴＲ１８００／ＴＥ３０ｍｓ），其中２例作了Ｇｄ－ＤＴＰＡ顺磁增强，所有病例均作了ＣＴ平扫，６例同时还作了增强ＣＴ扫描。通过本组病例分析：１     

慢性中耳炎病变组织的MRI鉴定诊断

目的：探讨ＭＲＩ鉴别胆脂瘤和内芽组织的能力。材料和方法：对１０例慢性中耳炎患者术前行ＭＲＩ扫描，计算病变组织驰豫时间（Ｔ２）的变化，与术后病理类型对照。结果：胆脂瘤、肉芽组织和脑组织之间，横向驰豫时间Ｔ２呈显著性差异（Ｐ〈０．０５），变化范围分别为８１２ｍｓ－４３２ｍｓ、１４７ｍｓ－９２２ｍｓ和１７４ｍｓ－１４４ｍｓ。结论：胆脂瘤、肉芽组织和脑组织横向驰豫时间（Ｔ２）具有可区别的范围，ＭＲＩ中Ｔ２     

髌股关节软骨退变的临床MRI研究

目的：以关节镜为标准,比较多序列ＭＲＩ对髌股关节软骨退变的诊断价值。材料与方法：４８个膝关节行关节镜检查及Ｖｏｌｕｍｅ－ＦＦＥ－Ｔ１ＷＩ矢状位ＳＥ－Ｔ１ＷＩ断位、ＦＦＥ－Ｔ、ＷＩ断位扫描。３Ｄ－Ｖｏｌｕｍｅ－ＦＦＥ－Ｔ１ＷＩ矢状位行多平面重建（ＭＰＲ）处理。１０例无症状志原者仅行ＭＲＩ扫描。ＭＲＩ图像每以关节分内、外有面、股骨滑车面与关节镜图像逐一对照分析。统计各序列诊断软骨病变的敏感性、特异性。     

实验性急性脊髓损伤MRI特点及与病理相关研究

目的 研究轻、重两组急性脊髓损伤（ＳＣＩ）的ＭＲＩ特点及ＭＲＩ信号类型与病理的关系。材料与方法 采用改良Ａｌｌｅｎ’ｓＷＤ法制成轻、重两组急性ＳＣＩ模型各８例,对照组６例,在损伤后第１２小时在０．５Ｔ ＭＲ仪扫描结束后处死取病理标本,光镜下观察病理变化。在ＭＲＩ矢状位最清晰层面上测定Ｔ１ＷＩ、Ｔ２ＷＩ、ＰＤＷＩ损伤区相对信号强度,上下径、前后径及损伤区面积并测定犬急性ＳＣＩ后的神经功能。结果 （１     

人颞下颌关节力的三维非线性有限元模拟

颞下颌关节 (ＴＭＪ)的力学环境对其正常的生理功能和某些疾病的形成与转归具有重要的作用 ,能够合理准确地模拟和认识ＴＭＪ内髁突、关节盘、关节窝之间力的传递与分布具有非常重要的临床意义。本研究利用Ａｕｔｏ ＣＡＤ软件及螺旋ＣＴ扫描技术与有限元应力分析方法相结合 ,在活体基础上建立ＴＭＪ三维非线性有限元模型 ,计算并分析正中咬合时ＴＭＪ的应力分布 ,以便更加真实合理地认识ＴＭＪ内力的分布与传递。1　材料与方法1.1　ＴＭＪ数字图像的获得及转换　选择成年健康女性志愿者 1名 ,作为建模素材。采用ＰｈｉｌｉｐＴｏ ｍｏｓｃ…     

慢性中耳炎病变组织的MRI鉴别诊断

目的：探索ＭＲＩ鉴别胆脂瘤和肉芽组织的能力。材料和方法：对１０例慢性中耳炎患者术前行ＭＲＩ扫描,计算病变组织驰豫时间（Ｔ２）的变化,与术后病理类型对照。结果：胆脂瘤、肉芽组织和脑组织之间,横向驰豫时间Ｔ２呈显著性差异（Ｐ＜０．０５）,变化范围分别为８１２ｍｓ－４３２ｍｓ、１４７４ｍｓ－９２２ｍｓ和１７４ｍｓ－１４４ｍｓ。结论：胆脂瘤、肉芽组织和脑组织横向驰豫时间（Ｔ２）具有可区别的范围,ＭＲＩ中Ｔ２值有助于鉴别上述不同的病理类型。     

听神经瘤的MRI表现与特征的再研究

目的：研究听神经瘤的ＭＲＩ表现与特征。方法：收集手术和病理证实的１３５例、１３８个听神经瘤的ＭＲＩ，其中微小听神经瘤为１０例，行Ｇｄ－ＤＴＰＡ增强扫描为４２例。结果：听神经瘤的ＭＲＩ的表现主要为：（１）肿瘤以内听道为中心生长，病侧第Ⅶ、Ⅷ神经束较对侧增粗，与肿瘤主体多无明确分界，增强后可见两者相连，颇为特征；（２）肿瘤在Ｔ１加权图像上呈低信号，略低信号或低等混合信号，Ｔ２加权呈高信号或高等混合信号；（３）注射Ｇｄ－ＤＴ－ＰＡ后肿瘤呈均匀，不均匀或环状强化；（４）肿瘤边界清晰，边缘光整；（５）绝大多数肿瘤患侧内听道前后径扩大，深径缩短；（６）微小听神经瘤的ＭＲＩ表现为第Ⅶ、Ⅷ神经束正常或局部结节状增粗，造影后呈结节状或点状增强。结论：ＭＲＩ是检查听神经瘤的有效方法，Ｇｄ－ＤＴＰＡ对微小听神经瘤的诊断很有价值。     

MRI三维重建对内耳内淋巴积液的诊断

梅尼埃氏病（Ｍｅｎｉｅｒｅ＇ｓ病）是常见的致晕疾病之一,其主要的组织病理学特征是内耳内淋巴腔的积液和膨胀。笔者旨在探讨ＭＲＩ三维成像对内耳内淋巴积液的诊断价值。１　材料及方法本组共９例病例,男性５例,女性４例,年龄４３～８４岁,平均年龄５０岁。病程１０ｈ～１０年。临床以眩晕、耳鸣、呕吐、听力下降疑诊梅尼埃氏病。　　ＭＲＩ扫描机采用德国Ｓｉｅｍｅｎｓ公司常导式ＯＰＥＮ型０．２Ｔ磁共振扫描成像系统,用头颅线圈,选择梯度回波三维成像序列（ＦＩＳＰ３Ｄ）,扫描参数为：ＴＲ１４．５ｍｓ,ＴＥ７ｍｓ,翻转角…     

A study of the relationship between the position of the condylar head and displacement of the temporomandibular joint disk.

OBJECTIVES: To examine the possible relationship between condylar position and disk displacement in the TMJ. METHODS: Forty-eight joints with no disk displacement (NDD), 84 joints with a reducible displaced disk (RDD) and 99 joints with a permanently displaced disk (PDD) were selected. The positions of the condyle and TMJ disk were calculated from lateral MR images. RESULTS: There were significant differences in condylar position between the joints with NDD and RDD, while there was no difference between those with NDD and PDD (Kruskal-Wallis and post-hoc test, P<0.05). There was also a significant correlation between the position of the condylar and the displaced disk (Spearman's rank correlation, P<0.05). The condyle was located more anteriorly with advancing disk displacement. CONCLUSIONS: We suggest that if the disk displacement is slight, the condyle is displaced posteriorly: as the disk displacement becomes more severe (i.e. more anteriorly displaced), the condyle returns to the concentric position.     

Temporomandibular joint: relationship between MR evidence of effusion and the presence of pain and disk displacement.

OBJECTIVE. The purpose of this study was to correlate MR evidence of joint effusion in the temporomandibular joint with symptoms of joint pain and the presence of disk displacement and arthrosis. SUBJECTS AND METHODS. The temporomandibular joints of 379 patients with clinical symptoms of temporomandibular joint disorders and 11 asymptomatic volunteers were imaged bilaterally. Sagittal and coronal proton density-weighted and T2-weighted images were obtained. Imaging findings of joint effusion were correlated with the presence of disk displacement and arthrosis and the symptom of pain. RESULTS. MR showed effusion in 7% of the joints with normal superior disk position, 40% of the joints with disk displacement with reduction, 50% of the joints with disk displacement without reduction, and 27% of the joints with arthrosis. Two of the control subjects had disk displacement with reduction; MR did not show joint effusion in any of the control subjects. A strong association was seen between joint effusion and joint pain. Joint effusion was seen in 46% of the joints on the more painful side and in 13% of the joints on the less painful side. CONCLUSION. The results show that temporomandibular joint effusions primarily occur in joints with disk displacement and are strongly associated with joint pain.     

Utility of frequency-selective fat saturation T2-weighted MR images for the detection of joint effusion in the temporomandibular joint

OBJECTIVES: To evaluate joint effusion in the temporomandibular joint (TMJ) using frequency-selective fat saturation (FS) T2-weighted images and assess this technique. To investigate whether bone marrow abnormalities and magnetic resonance imaging (MRI) findings of internal derangement may be linked to joint effusion in the TMJ in patients with pain. METHODS: TMJ effusion was sought on FS T2-weighted images and conventional T2-weighted images in 400 joints from 200 patients with TMJ-related pain. Self-reported pain records were obtained from patients immediately before MRI and images assessed by the amount of TMJ fluid graded bilaterally using reference films by two radiologists. Other parameters recorded included disk displacement categories and condyle marrow abnormalities. The association between the recorded parameters and TMJ effusion judged by FS-sequences or conventional sequences was analysed using chi-square and Kappa tests. RESULTS: The detection rate of TMJ effusion by FS-sequences was significantly greater than by conventional methods, and the results showed a significant relationship between MRI interpretation of TMJ effusion using FS-sequences or conventional methods and the presence of pain. The correlation between TMJ effusion on FS-sequences and pain was significantly stronger than the conventional method. Kappa test indicated good agreement between pain and MRI TMJ effusion by FS-sequences (kappa = 0.66), but not by conventional sequences (kappa = 0.56). The other parameters showed a similar trend for TMJ-related pain. CONCLUSIONS: FS T2-weighted imaging is useful for detection of TMJ effusion, without known causes and confirms the importance of TMJ effusion as an indicator in patients with TMJ-related pain, bone abnormalities, and disk displacement.     

Resorption of the lateral pole of the mandibular condyle in temporomandibular disc displacement

OBJECTIVES: To assess the possible relationship between resorption of the superolateral pole of the mandible condyle (RSLC) and TMJ disk displacement. METHODS: Two hundred and seventeen TMJs in 138 patients were studied. Displacement of the disc, degree of displacement and disc configuration were assessed using MRI. RSLC was assessed from a transorbital radiograph. RESULTS: Seventy-two joints (37%) were considered to have RSLC. A significantly higher prevalence of RSLC was found in joints with disc displacement (goodness test of fit for chi-square, P<0.05). A significantly higher prevalence of RSLC was found in joints with advanced disc displacement and advanced disk deformation (Mann-Whitney U-test, P<0.01). CONCLUSIONS: RSLC appears more likely to occur in joints with advanced disc displacement.     

MR imaging of temporomandibular joint abnormalities associated with cervical hyperextension/hyperflexion (whiplash) injuries.

Patients often have temporomandibular joint (TMJ) dysfunction-related symptoms after cervical hyperextension/hyperflexion injuries ("whiplash") caused by rear-end motor-vehicle collisions. To determine abnormalities of the TMJ associated with these injuries, 33 consecutive symptomatic patients (66 joints) with no direct trauma to the jaw, mouth, head, or face due to the accident and no prior history of TMJ dysfunction underwent magnetic resonance (MR) imaging, and the images were retrospectively analyzed. Overall, 29 (88%) patients had some type of TMJ abnormality related to whiplash injury. Displacement of the disk was seen in 37 (56%) of the TMJs as follows: 21 (32%) had anterior displacement with reduction, nine (14%) had anterior displacement without reduction, six (9%) had lateral or medial displacement, and one (2%) had posterior displacement. On T2-weighted images, 43 (65%) TMJs had abnormal joint fluid or edema, predominantly affecting the joint capsule and/or lateral pterygoid muscles. The finding that many of the patients had joint fluid and/or soft-tissue edema indicates that T2-weighted images are especially useful for assessment of patients with a history of whiplash injury.     

Thickening of the glenoid fossa in osteoarthritis of the temporomandibular joint. An autopsy study

OBJECTIVE: To evaluate the thickness of the roof of the glenoid fossa of the temporomandibular joint (TMJ) in relationship to the stage of internal derangement from autopsy material. MATERIAL AND METHODS: The minimum thickness of the roof of the glenoid fossa was measured with a caliper in 61 TMJ autopsy specimens. Based on macroscopic examination the joints were categorized as normal (30 joints), disk displacement (eight joints), disk displacement with osteoarthritis (12 joints) and osteoarthritis with perforation of the disk or posterior attachment (11 joints). The relationship between thickness of roof of the glenoid fossa and status of the joint was analysed. RESULTS: The roof of the glenoid fossa was on the average 0.6 mm in normal joints, 1.1 mm in joints both with disk displacement and disk displacement with osteoarthritis and 2.6 mm in joints with osteoarthritis and perforation. The difference between the normal joints and those with perforation was significant (P<0.01). CONCLUSION: Progressive remodeling with thickening of the roof of the glenoid fossa seems to be associated with perforation of the disk or posterior attachment.     

Severity of synovium and bone marrow abnormalities of the temporomandibular joint in early rheumatoid arthritis: role of gadolinium-enhanced fat-suppressed T1-weighted spin echo MRI

PURPOSE: Our goal was to evaluate the efficacy of dynamic contrast-enhanced fat-suppressed MRI of the temporomandibular joint (TMJ) in detecting early joint involvement in patients with rheumatoid arthritis (RA). METHOD: Conventional T1- and T2-weighted, gadolinium-enhanced T1-weighted, and dynamic gadolinium-enhanced fat-suppressed SE imaging sequences were performed in 22 patients with RA. RESULTS: The dynamic gadolinium-enhanced fat-suppressed T1-weighted SE sequence was more sensitive than the other techniques in detecting early changes in inflamed synovium of periarticular tissue and in detecting condylar bone marrow involvement. In patients with RA, 17 joints with joint pain showed synovial proliferation in 10 (59%) cases and joint effusion in 4 (24%). Of 14 joints with joint sound, 4 (29%) showed synovial proliferation and 7 (50%) showed joint effusion. A lower positional change of the disk was observed in joints with RA than in those with TMJ disorders (82 patients). CONCLUSION: Gadolinium-enhanced fat-suppressed MRI was extremely effective in diagnosing early changes of the inflamed TMJ.     

Image quality using dynamic MR imaging of the temporomandibular joint with true-FISP sequence.

We evaluated the quality of dynamic magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) in 20 normal volunteers with 40 TMJs. To confirm TMJ, we obtained static proton density weighted images (PDWI) before performing dynamic MR imaging with true-fast imaging in a steady-state precession (true-FISP) sequence. Four sequences of the first 10 volunteers were examined to determine the optimal sequence. The 4 sequences included the integrated parallel acquisition technique (iPAT) and/or fat saturation technique. The optimal sequence was then determined and performed in all 20 volunteers. The quality of imaging was evaluated, especially with respect to the conspicuity of the articular disk, mandibular condyle, articular eminence and lateral pterygoid muscle. One of 3 confidence levels was assigned for this evaluation. Neither iPAT nor fat saturation obtained the best quality imaging. Detection rates in the 20 volunteers were 83% for the articular disk, 95% for the mandibular condyle, 96% for the articular eminence and 7.5% for the lateral pterygoid muscle. We recommend dynamic MR imaging of the TMJ with the true-FISP sequence using neither iPAT nor fat saturation. Nevertheless, dynamic MR imaging was inferior to static imaging in detecting the articular disk and still requires improvement.     

Relationship between increased horizontal condylar angle and resorption of the posterosuperior region of the lateral pole of the mandibular condyle in temporomandibular joint internal derangement

OBJECTIVES: The purpose of this study was to analyse the relationship between horizontal condylar angle, temporomandibular joint (TMJ) disk displacement and resorption of the lateral pole of the mandibular condyle (RLC). METHODS: The study comprised 162 TMJs (81 patients). Disk displacement was assessed and the horizontal angle of the condyle was measured on axial MR images. RLC was assessed on oblique frontal projection plain radiographs. RESULTS: The horizontal angle was increased in joints with disk displacement without reduction (one-factor ANOVA and Scheffe's f-test, P<0.05). The angle was greater in joints with RLC than in the joints without RLC (Student's t-test, P<0.05). CONCLUSIONS: Results suggest that the horizontal condylar angle is increased in joints with disk displacement without reduction. A possible relationship exists between RLC and increased horizontal condylar angle.     

Influence of mouthguard on temporomandibular joint

The aim of this study is to examine whether wearing a mouthguard (MG) has an influence on temporomandibular joint (TMJ) components (i.e., the condyle and the articular disk) and whether clenching with a resilient MG has an effect on the same components. Twenty-six healthy volunteers (15 females, 11 males) with an age range of 26-42 years old (median 28 years) participated in this study. Among all 52 joints in the 26 subjects, anterior disk displacement (AntDD) was recognized in 15. Thus, we classified the 52 joints into two groups, the AntDD group and the Normal group. Resilient thermoplastic materials were used to fabricate two types of MG, one that raised the vertical dimension height by 3 mm and another that raised it by 6 mm. Subjects were scanned with/without two types of MG with/without clenching by magnetic resonance imaging (MRI). The movement of the condylar head and articular disk was measured in the magnetic resonance images using the special subtraction technique. Wearing the MG without clenching did not have a negative influence on the TMJ and clenching in the Normal group. In the AntDD group, however, the relationship between the disk and condyle was affected by clenching and the degree of disk displacement was worsened by clenching with the thicker MG. From our results, we recommend that athletes with an internal derangement of the TMJ not wear the thicker MG and attention should be paid to its setting. And the subtraction technique using MRI was thought as a good tool for detecting a slight change in the TMJ.