Neurinoma of the oculomotor nerve: CT and MR features

The authors present a case of neurinoma of the oculomotor nerve without evidence of von Recklinghausen disease. The literature is reviewed and CT and magnetic resonance findings are discussed.     

MR arthrography of elbow: evaluation of the ulnar collateral ligament of elbow

 Objective. The purpose of this study was to evaluate ulnar collateral ligament (UCL) injury of the elbow in throwing athletes by MRI and MR arthrography. Design. Ten elbows of throwing athletes were examined on both plain MRI and MR saline arthrography and the injuries subsequently surgically proven. Spin-echo (SE) T1-weighted and fast SE T2-weighted coronal images were obtained. Results. The UCL was unclear in all ten cases on T1-weighted MRI. In five cases an avulsion fracture was also found on T1-weighted MRI. On T2-weighted MRI, abnormal high-intensity areas were identified in or around the UCL. On T2-weighted MR arthrography images, extracapsular high-intensity areas, which represent extracapsular leakage, were found in four of five cases with avulsion fracture. At surgery, all these four cases showed avulsion fractures with instability; the other case had a fracture but it was stable and adherent to the humerus. On T2-weighted MR arthrography images, an extracapsular high-intensity area was found in one of the five cases without avulsion fracture. At surgery this patient had a complete tear of the UCL itself. Conclusion. MR arthrography provided additional information for evaluating the degree of UCL injury.     

肘关节疾病的MRI研究

目的探讨MRI在肘关节病变的应用价值。方法154例有肘关节疼痛、活动障碍或不适患者行肘关节MR检查,包括冠状位、矢状位及横断位成像,序列包括T1wI自旋回波（T,WISE）,T2WI自旋回波压脂（T：WIFS）,质子密度加权成像自旋回波压脂（PDWIFS）。俯卧位108例,仰卧位46例,使用膝关节线圈及表面线圈。结果154例患者中,关节正常表现25例,关节异常患者129例（83．8％）。其中炎性疾病38例（29．5％）,包括骨性关节炎32例,风湿性关节炎5例,关节结核1例。肿瘤或肿瘤样疾病28例（21．7％）,包括滑膜软骨瘤病4例,腱鞘巨细胞瘤1例,神经鞘瘤3例,腱鞘囊肿5例,滑膜囊肿15例。损伤性疾病63例（48．8％）,包括韧带损伤24例,肌腱损伤28例,尺神经损伤11例。结论磁共振对肘部疾病的诊断具有很好的价值。     

MR imaging of trauma: elbow and wrist

The use of magnetic resonance imaging (MRI) in the setting of acute trauma is increasing due to many factors including availability and demand. The ability to evaluate for occult fractures in addition to concomitant soft tissue injuries has a significant impact on patient management and MRI is the ideal adjunct to plain radiography. Occult fractures in the forearm, particularly the radial head and scaphoid, are common and often lead to repeated examinations and delayed diagnosis, which can be avoided by the use of MRI early in patient investigation. Orthopedists are increasingly performing ligament repairs at the time of fracture fixation and therefore benefit from preoperative MRI to assess the extent of soft tissue injury.     

Neurosyphilis as a cause of facial and vestibulocochlear nerve dysfunction: MR imaging features

The prevalence of syphilis increased for several decades before the mid-1990s in the United States, particularly in the southern states. We report a case of neurosyphilis causing bilateral facial and vestibulocochlear nerve dysfunction in which the diagnosis was not initially suspected based on the patient's demographics and history. The MR imaging features helped to make the diagnosis in this case and to exclude other possible causes of multiple cranial nerve dysfunction in this patient. Hearing loss associated with neurosyphilis is one of the few treatable forms of progressive hearing loss, and it is essential that a diagnosis of neurosyphilis be made expeditiously.     

MR imaging of the elbow.

Of 27 patients who underwent magnetic resonance (MR) imaging of the elbow, 11 underwent elbow arthroscopy and/or an open surgical procedure. Surgical findings were compared with those from MR imaging. Five healthy volunteers also underwent MR imaging to demonstrate anatomic relationships. Transchondral fracture (osteochondritis dissecans) was identified in three of the 11 patients and was proved at surgery. Loose bodies were suspected at MR imaging in the three patients but were found in only two. One complete avulsion of the ulnar collateral ligament (UCL) and four cases of intact, thickened UCLs were identified at MR imaging and surgery. Loose bodies from the olecranon tip were found in three patients at surgery but were seen on MR images in only two. MR imaging depicted olecranal osteophytes in three cases, which were confirmed at surgery. Two complete avulsions of the biceps tendon and one partial triceps tendon tear were identified with MR imaging and proved at surgery. A postoperative soft-tissue infection and a synovial cyst were also seen at MR imaging and surgery. These results suggest that MR imaging is useful in the evaluation of the elbow.     

Intramuscular myxoma: MR features

Intramuscular myxoma is a benign mesenchymal lesion consisting of bland spindled cells embedded in an avascular myxoid stroma. On CT, intramuscular myxoma presents as a well-demarcated, homogeneous, low density mass situated within skeletal muscle. The attenuation of the lesion is slightly greater than water but less than that of the surrounding normal muscle, with typical values between +10 and +60 HU. There is scant magnetic resonance (MR) literature on the appearance of intramuscular myxoma; the few MR spin echo images that have been published characterize it as a homogeneous mass with signal intensity less than or equal to skeletal muscle on T1-weighted and brighter than fat on T2-weighted pulse sequences. We present two cases of intramuscular myxoma with imaging characteristics that differ from those previously reported.     

Pericallosal lipomas: MR features

We report on six cases of pericallosal lipomas. The T1-weighted sagittal images best demonstrated the relationship between the lipoma and the corpus callosum. In four cases the lipomas surrounded the splenium of the corpus callosum and in two cases the tumors were situated posteriorly and caudally to the splenium. In no case did we encounter an exclusively dorsal pericallosal localization.     

Arthroscopic managementof miscellaneous elbow disorders

Surgical arthroscopy is indicated primarily in the treatment of radiocapitellar disorders and soft tissue disorders, or bony ankylosis of the elbow joint. However, there are other elbow conditions in which the arthroscope is beneficial, particularly by the treatment of lateral epicondylitis and olecranon bursitis. Chronic lateral epicondylitis can result in damage to the common origin of the extensor carpi radialis brevis muscle. Lesions range from microtears to attenuation and tearing or rupture of the tendon. The damage has been classified arthroscopically into the following three types: type I consists of inflammation and fraying, type II consists of linear tears of the undersurface of the extensor carpi radialis brevis tendon, and type III is an avulsion of the tendon and overlying capsule. Operative treatment involves debriding the diseased capsule and releasing of the tendinous origin of extensor carpi radialis brevis muscle and decorticating the lateral epicondyle. Clinical results of this technique are encouraging. Direct trauma is the most common cause of olecranon bursitis, but it can also be caused by infection or inflammation. Although best managed nonoperatively, the condition may require surgical intervention. The arthroscope is used to excise the olecranon bursa and examine the olecranon tip for spurs. Early results of this procedure have also been encouraging with no major complications or infections.     

The knee after partial meniscectomy: MR imaging features

The magnetic resonance (MR) examinations of 51 menisci treated by means of partial meniscectomy were reviewed. Menisci were divided into three groups: group 1, near normal length without osteoarthritis; 2, substantially shortened without osteoarthritis; and 3, any length with osteoarthritis. Group 1 menisci resembled normal menisci except for mild shortening and frequent signal inhomogeneity (56%). Group 2 menisci varied in appearance, with marked contour irregularity simulating fragmentation in 40% of segments despite a normal postoperative appearance at follow-up arthroscopy. Group 3 menisci appeared similar to menisci of the same length without osteoarthritis. Arthroscopic correlation, available for 23 menisci (45%), confirmed the MR diagnosis of a tear in 11 and no tear in 49 and revealed an unsuspected tear in three meniscal segments. There is a spectrum of normal MR appearances after partial meniscectomy. Standard MR criteria can be used to diagnose tears in the absence of marked contour irregularity; however, the diagnosis of tears of segments with marked contour irregularity must be made cautiously, since this irregularity can mimic a tear and was not predictive of an arthroscopically visible tear.     

MR and CT arthrography of the elbow

Magnetic resonance (MR) arthrography has, to a great extent, replaced conventional and CT arthrography as the standard of care imaging tool for indications including medial elbow pain in the throwing athlete, chondral and osteochondral lesions in the elbow, and intra-articular bodies. There are still rare specific incidences where CT arthrography is indicated. This article reviews elbow arthrography, with a greater emphasis placed on MR arthrography, including indications, technique, potential complications, contraindications, equipment, and MR arthrographic pathologies.     

脊髓表皮样囊肿的MR诊断

目的分析脊髓表皮样囊肿的ＭＲ表现，以提高对该病的神经放射学认识。材料与方法搜集１８例经手术病理证实的脊髓表皮样囊肿。重点分析了肿瘤的好发年龄、部位、ＭＲ信号特点和肿瘤的增强情况。结果在本组病例中，病人年龄最小４岁，最大４２岁，平均年龄２４．５岁。本组病例全部发生于圆锥附近，边缘清楚。大部分肿瘤长度小于２个椎体长度（１６／１８），２例肿瘤长度大于３个锥体长度，Ｔ１加权像肿瘤呈均匀的等（６／１８）、高（２／１８）和混杂信号（１０／１８）。Ｔ２加权像呈高信号，边缘可呈等Ｔ２信号。在７例行增强扫描的病人中，有４例肿瘤周围可见轻微强化，３例无强化。９例肿瘤内可见脂肪信号。本组中未见其他有关先天性畸形。结论脊髓内表皮样囊肿的ＭＲ表现较具特征性。该病多见于青年患者，好发于圆锥附近，多呈长Ｔ１、Ｔ２信号。增强扫描无或仅有周围轻微强化。     

副肿瘤性边缘叶脑炎的临床及MRI特征

【摘要】目的：探讨副肿瘤性边缘叶脑炎（PLE）的MRI特征。方法：回顾性分析8例经临床诊断治疗的PLE的临床及MRI资料。所有患者均行常规MRI平扫及DWI检查,其中6例行增强扫描。结果：①8例病变分布均以海马及海马旁回为主,其中3例可见病变同时累及双侧杏仁核、2例累及双侧扣带回、1例累及左侧岛叶、1例累及桥脑。病变双侧对称分布7例,单侧发病1例。②信号特征：6例病变于T1WI上呈较均匀稍低信号,T2WI呈高信号,DWI呈稍高或等信号;2例于T1WI呈等信号,T2WI呈稍高信号,DWI呈等信号;所有病灶在FLAIR图像上均呈高信号。6例行增强扫描,5例病变无强化,1例可见小片状轻度强化。结论：PLE具有较典型的临床及MRI特征,应结合抗体检测及其它全身检查,积极寻找原发肿瘤进行综合治疗。