Magnetic resonance imaging of nontraumatic shoulder instability in children

Nontraumatic shoulder instability is infrequent in children. We examined prospectively with high-field magnetic resonance imaging (MRI) 11 patients with this disorder, including 2 with Holt-Oram syndrome and 11 healthy control subjects. The MR findings in the glenohumeral joint in normally growing children are presented. Two patients with shoulder instability were considered as normal, one presented with type 2 (Zlatkin) labral lesions, three, type 3 and one, type 4 lesions. Close attention to the normal imaging patterns of the maturing glenohumeral joint is required to avoid pitfalls in the interpretation of the images.     

Magnetic resonance imaging in glenohumeral instability

The glenohumeral joint is the most commonly dislocated joint of the body and anterior instability is the most common type of shoulder instability.Magnetic resonance (MR) imaging,and more recently,MR arthrography,have become the essential investigation modalities of glenohumeral instability,especially for pre-procedure evaluation before arthroscopic surgery.Injuries associated with glenohumeral instability are variable,and can involve the bones,the labor-ligamentous components,or the rotator cuff.Anterior instability is associated with injuries of the anterior labrum and the anterior band of the inferior glenohumeral ligament,in the form of Bankart lesion and its variants;whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesion.Multidirectional instability often has no labral pathology on imaging but shows specific osseous changes such as increased chondrolabral retroversion.This article reviews the relevant anatomy in brief,the MR imaging technique and the arthrographic technique,and describes the MR findings in each type of instability as well as common imaging pitfalls.     

肩关节损伤MRI与关节镜的对比分析

目的探讨常规MRI对肩关节损伤的诊断价值。方法回顾性分析因肩关节损伤行常规MRI和关节镜检查的55例病人资料,MRI观察指标包括肩袖、盂唇形态及信号,有否肩峰下撞击及骨性损伤。以肩关节镜为诊断金标准,统计MRI对不同类型肩关节损伤的诊断结果,并分别计算MRI的诊断敏感度、特异度和准确度。采用Kappa检验分析MRI与肩关节镜诊断结果的一致性。结果肩关节损伤的MRI征象中分别有25%部分肩袖撕裂、13.3%Bankart’s损伤、20%盂唇上部前后方向(SLAP)损伤和11.6%肩峰下撞击漏诊。MRI诊断损伤性病变的特异度及肩袖全层撕裂(100%)、骨性损伤(100%)、肩峰下撞击(88%)和Bankart’s损伤(87%)的敏感度较高,诊断SLAP损伤(75%)和肩袖部分撕裂(75%)的敏感度较低;诊断肩袖全层撕裂(100%)和骨性损伤(100%)的准确度最高,其次是Bankart’s损伤(96%),诊断SLAP损伤(89%)的准确度较低。MRI和关节镜诊断肩袖全层撕裂、骨性损伤的κ值为1,结果完全一致,诊断Bankart’s损伤的κ值为0.904,一致性较好,诊断肩袖部分撕裂、SLAP损伤和肩峰下撞击的κ值虽稍低,但均0.75,一致性也较好,P均0.05。结论 MRI是有效诊断肩关节损伤的影像方法,但对SLAP损伤和肩袖部分撕裂的诊断准确度有待提高。     

完全型心内膜垫缺损的MRI诊断

目的 评价ＭＲＩ对完全型心内膜垫缺损的诊断价值和限度。方法 对８例（男５例,女３例）患者行自旋回波（ＳＥ）和电影ＭＲＩ诊断。诊断由Ｘ线平片,超声心动图,Ｘ线右心导管加心血管造影以及ＭＲＩ等多种影像学技术作出,其中４例行手术治疗。结果 ＭＲＩ显示心脏各个房室腔扩大,多数以右心房室扩大为著,伴有右心室壁增厚心内膜垫结构消失,４个心腔呈“十”字形直接相通,形成膜部空间隔缺损和Ｉ孔型空间隔缺损,二,三尖瓣     

Symptomatic ring-shaped lateral meniscus: magnetic resonance imaging and arthroscopy

A ring-shaped lateral meniscus is a very rare entity within the spectrum of abnormalities of lateral meniscus. We present the second case in the literature of a symptomatic ring-shaped lateral meniscus in combination with a meniscal cyst and in association with an osteochondritis dissecans lesion of the medial femoral condyle. A potential pitfall of magnetic resonance imaging (i.e., displaced meniscal tear) is addressed in the diagnosis of this entity, as well as the role of magnetic resonance imaging in revealing associated abnormalities.     

Magnetic resonance imaging of double-bundle anterior cruciate ligament reconstruction

Reconstruction of the anterior cruciate ligament (ACL) using the double-bundle technique is getting highly increasing attention. This surgical approach uses two separate tendon grafts with the intention to reconstruct both anatomic bundles in order to restore the full biomechanical function of the original ligament. With the increasing popularity of this technique, radiologists will be more frequently confronted with patients who underwent this surgical procedure. The aims of this essay are to briefly describe the basic biomechanical and surgical principles and to summarize the magnetic resonance imaging findings of the knee after double-bundle ACL reconstruction. Grants or Funding None.     

Magnetic resonance imaging of pyomyositis

Pyomyositis is a relatively rare entity in temperate climates. Because of its rarity and its nonspecific clinical and radiographic findings, pyomyositis may be misdiagnosed and may cause severe morbidity and mortality. We present magnetic resonance imaging findings in two cases of pyomyositis. Magnetic resonance imaging was helpful in differentiating other pathological processes from pyomyositis, outlining the extent of involvement, and localizing the fluid collection.     

烟雾病的MRI、MRA诊断价值

 目的探讨MRI、MRA对烟雾病(Moyamoya病)的诊断价值.方法对11例Moyamoya病患者行MRI和MRA检查,MRI包括横轴位和矢状位T1WI、T2WI、FLAIR;MRA采用3D TOF法,3例行增强MRA.结果MRI表现为:(1)Moyamoya血管:双侧3例,单侧8例;(2)脑梗死和脑软化灶11例;(3)局部脑萎缩3例.MRA表现为3例双侧颈内动脉狭窄,双侧大脑中、前动脉闭塞,大脑后动脉形成异常血管网;6例右侧颈内动脉、大脑中动脉狭窄;2例左侧颈内动脉、大脑中动脉狭窄.结论MRI能良好的显示脑内病变,MRA能较完整的显示异常血管,MRI与MRA相结合可作为烟雾病诊断的首选检查方法.     

Magnetic resonance imaging versus bone scintigraphy in suspected scaphoid fracture

Magnetic resonance imaging (MRI) has become increasingly useful in the evaluation of musculoskeletal problems, including those of the wrist. In patients with a wrist injury, MRI is used mainly to assess vascularity of scaphoid non-union. However, the use of MRI in patients in the acute phase following carpal injury is not common. Three-phase bone scintigraphy is routinely performed from at least 72 h after injury in patients with suspected scaphoid fracture and negative initial radiographs. We evaluated MRI in this patient group. The bone scan was used as the reference method. Nineteen patients were included. Bone scintigraphy was performed in all 19 patients, but MRI could be obtained in only 16 (in three patients, MRI was stopped owing to claustrophobia). In five patients, MRI confirmed a scintigraphically suspected scaphoid fracture. In one patient, a perilunar luxation, without a fracture, was seen on MRI, while bone scintigraphy showed a hot spot in the region of the lunate bone, suspected for fracture. This was confirmed by surgery. In two patients, a hot spot in the scaphoid region was suspected for scaphoid fracture, and immobilization and employed for a period of 12 weeks. MRI was negative in both cases; in one of them a scaphoid fracture was retrospectively proven on the initial X-ray series. In another two patients, a hot spot in the region of MCP I was found with a negative MRI. In both, the therapy was adjusted. In the remaining six patients, both modalities were negative. We conclude that in the diagnostic management of patients with suspected scaphoid fracture and negative initial radiographs, the use of MRI may be promising, but is not superior to three-phase bone scintigraphy.     

Magnetic resonance tomographic angiography in the investigation of hemifacial spasm

Magnetic resonance angiography (MRA), combined with submillimeter magnetic resonance tomographic angiographic sections (MRTA) showed vascular compression of the 7th cranial nerve or its root exit zone (REZ) in the brain stem in 24 of 37 patients (64.86%) with hemifacial spasm. MRA alone was positive for REZ compression in only 19 (51.4%) cases, while conventional MRI was even less revealing, only 10 (27%) cases being positive.     

Comparison between magnetic resonance imaging and arthroscopy in the diagnosis of patellar cartilage lesions

A blind and prospective study was conducted to assess the accuracy of magnetic resonance imaging (MRI) for diagnosing patellar cartilage lesions. Thirty-three consecutive patients undergoing knee arthroscopy were examined by MRI prior to surgery. Imaging was performed in the axial plane on a 1.5-Tesla unit with spinecho and gradient-echo T1 and T2 sequences. The MRI and arthroscopic data were compared using a four-grade classification and a patellar map which divided the patellar surface into four quadrants. The overall sensitivity of MRI was 84.7% and the specificity 97.2%. The same pit-fall led to two MRI false positives. A perfect correlation of grading was obtained in 76.5%. When discordance was found, the tendency with MRI was commonly to underestimate the grade of the lesions. The MRI accuracy was high in this study in spite of a high rate of low-grade lesions which are difficult to assess. Related criteria for cartilage assessment with MRI and arthroscopy are suggested for further studies.     

关节软骨MR成像进展

随着软骨序列的开发和应用，MRI对关节软骨的评价越来越重要。本文就关节软骨的MRI表现、关节软骨的MRI序列和扫描技术、关节软骨损伤以及修复术后MRI评价等方面进行了综述。     

胎儿肾脏积水的MR影像及预后评估

目的利用1．5T高场强扫描机,对胎儿肾脏积水的MR影像及预后进行评估。方法利用B超筛查发现胎儿肾脏积水并进行MR进一步检查的病例34例,胎龄24～37周。结果在34例胎儿中,MR诊断单侧重复肾伴上半肾积水3例（1例产后MR证实,2例引产）,盆腔内囊性病灶致双侧肾脏积水2例（1例产后证实为盆腔巨大畸胎瘤致双肾积水,1例失访）,脑室扩张且单侧肾脏积水2例（1例引产,1例失访）,双侧’肾脏及输尿管扩张积水且肺发育不良1例（产后MR证实,放弃治疗）,双侧肾脏积水伴脐膨出1例（产后证实为脐肠瘘并行手术治疗,双侧肾脏积水随访改善）,双侧肾脏积水伴左肾周积液1例（引产）,单纯性肾脏积水24例（产后确诊左侧UPJ进行手术3例,左侧肾脏积水随访中2例,6例左侧、2例右侧及5例双侧肾脏积水产后超声随访正常,失访6例）;产后确诊UPJ的3例胎儿肾脏皮质厚度平均2mm,随访正常的13例胎儿肾脏皮质厚度平均3．5mm。结论MR影像能够对胎儿肾脏积水的病因进一步评估,有利于胎儿肾脏积水的预后判断。     

肩关节损伤的MRI评价

肩关节损伤往往带有关节囊内外非骨性结构的损伤，由于MRI对软组织结构比X线平片及CT能更好成像显示，MRI成为肩关节损伤检查的重要方法。本文复习了肩关节加MRI成像方法及正常解剖结构，综合评述肩关节损伤常见病变特征及MRI表现。     

Magnetic resonance imaging of the shoulder: rationale and current applications

Because it can demonstrate a wide range of tissue contrast with excellent resolution, magnetic resonance (MR) imaging has revolutionized imaging in many areas of the musculoskeletal system and has generated excitement among those interested in the painful shoulder. Shoulder impingement syndrome and glenohumeral instability constitute the two major categories of shoulder derangements. Correct diagnosis requires the use of appropriate pulse sequences and imaging planes, proper patient positioning, and a satisfactory surface coil. In addition the imager must have a thorough understanding of shoulder anatomy and pathology. We present a summary of the current status of MR imaging of the shoulder including technical, anatomic, and pathologic considerations and a review of the pertinent literature.     

MRI和关节镜诊断膝半月板损伤的比较研究

目的 :探讨膝关节半月板损伤MRI和关节镜下的不同表现及其对半月板损伤的诊断意义。方法 :回顾性分析 10 2个半月板损伤的MRI表现和关节镜下图像。根据MRI信号改变将半月板损伤分为Ⅰ级、Ⅱ级、Ⅲ级 ,并与关节镜下所见对比 ,分别加以研究。结果 :根据MRI信号强度改变 ,10 2个膝关节中Ⅰ级损伤 3 4个 ,Ⅱ级损伤 2 7个 ,Ⅲ级损伤 41个。与关节镜检结果对比 ,MRI诊断半月板撕裂的敏感度 90 .0 % ,特异度 91.9% ,符合率 91.2 %。结论 :MRI在半月板损伤的诊断中具有极高价值 ,对指导患者的治疗具有重要的临床意义。     

Magnetic resonance imaging of musculoaponeurotic fibromatosis

Musculoaponeurotic fibromatosis can be mistaken for soft-tissue sarcoma both clinically and on X-ray computed tomography. Magnetic resonance imaging (MRI) in three patients with this condition enabled the correct diagnosis to be made prospectively in two. The appearance on MRI of a heterogeneous mass with well-defined, predominantly peripheral areas of very low signal intensity due to dense fibrous tissue and areas of medium to high signal intensity corresponding to a more cellular stroma should raise the the suspicion of musculoaponeurotic fibromatosis. Cellular areas within the tumour showed moderate enhancement after gadolinium diethylene triamine pentaacetic acid administration.     

Magnetic resonance imaging of limbic encephalitis

Summary In two patients with limbic encephalitis serial magnetic resonance (MR) imaging showed evolution of abnormal high-signal intensity in both hippocampal formations on T2-weighted images.     

Magnetic resonance imaging of the craniocervical junction

Magnetic resonance imaging has become the study of choice for the majority of abnormalities of the craniocervical junction as well as for demonstration of primary pathology of the spinal cord, and brain stem. Although the applications of MR are currently limited by its high cost, relatively long scan time, and low sensitivity to calcification, new pulse sequences, faster scan strategies, and lower cost MR scanner are changing this situation. MR contrast agents and the use of 3-D imaging techniques combined with gradient echoes promise to play a role in MR of the craniocervical junction in the near future.     

Magnetic resonance imaging and 1H-magnetic resonance spectroscopy in amyotrophic lateral sclerosis

We aimed to increase confidence in the combined use of MRI and proton MR spectroscopy (¹H-MRS) in diagnosis of amyotrophic lateral sclerosis (ALS). We investigated 12 patients with ALS, seven definite and five probable, taking into account clinical measures of motor neuron function. On T2-weighted images we found high signal in the corticospinal tract in six and low signal in the primary motor cortex in seven of the 12 patients. Atrophy of the precentral gyrus was apparent in all the patients apart from one with probable ALS. Absolute quantification of cerebral metabolites using ¹H-MRS demonstrated a significantly lower mean concentration of N-acetylaspartate (NAA) in the precentral gyrus of patients with probable and definite ALS (8.5 ± 0.62) than in control subjects (10.4 ± 0.71; P < 0.001). NAA concentration in primary motor cortex correlated with Norris scale scores (r = 0.30; P < 0.0001) but not with the ALS Functional Rating Scale score or disease duration. Significantly lower levels of NAA were detected in patients with low signal in the motor cortex than in those without (P < 0.01). Mean choline (Cho) and creatine (Cr) values did not differ between patients with ALS and controls. Received: 20 July 2000 Accepted: 1 September 2000