Vaccination-induced myositis with intramuscular sterile abscess formation

A case is presented of a 17-month-old female who acutely refused to bear weight on her left leg. A mass was felt and initially thought to represent a neoplasm. There were no constitutional symptoms. MRI demonstrated an area of edema involving the vastus medialis, vastus intermedius, and vastus lateralis with central fluid collection. Culture of the fluid component yielded no growth. Investigation determined the patient had received a DPT vaccination 10 days earlier into the thigh area of the left leg. This is the first MRI demonstration of vaccination-induced myositis with intramuscular sterile abscess formation.     

MRI findings in intramuscular lipomas

Objective. To investigate the spectrum of magnetic resonance (MR) findings of intramuscular lipoma. Design and patients. A retrospective review of 17 consecutive cases of intramuscular lipoma examined with MR imaging was undertaken. Features assessed included the size and margin of the mass; the homogeneity of the contents, including the presence or absence of intermingled muscle fibers; whether the mass was uninodular or multinodular; and the presence of linear structures between and within the tumor nodules. Three well-differentiated liposarcomas and one dedifferentiated liposarcoma associated with lipoma-like components were also studied to allow a comparison of the benign and malignant lesions. Results. The diameter of the intramuscular lipomas varied from less than 3 cm to more than 10 cm. Ten of the intramuscular lipomas were homogeneous but the remaining seven were inhomogeneous with intermingled muscle fibers within the mass. The intramuscular lipomas were well defined in 12 cases, and infiltrative in five. In one case the margin of the lesion showed prominent infiltration of the surrounding muscle tissue. Of the 17 cases of intramuscular lipoma, 15 were composed of a single nodule, whereas three of four cases of liposarcoma were composed of multinodular masses. Conclusion. The MR findings of intramuscular lipoma varied from a small, single and homogeneous mass identical to ordinary (superficial) lipoma, to a large, inhomogeneous lesion with an infiltrative margin. The presence of infiltrative margins and intermingled muscle fibers in intramuscular lipoma indicates a benign lesion rather than malignancy. In addition, uninodularity of the mass is helpful in differentiating intramuscular lipoma from well-differentiated liposarcoma. Received: 26 May 1998 Revision requested: 7 August 1998 Revision received: 10 November 1998 Accepted: 16 November 1998     

骨化性肌炎的X线、CT及MRI表现

列示病变呈高等低混杂信号,边界不清.晚期T1WI和T2WI均呈低信号,周边无水肿.MRI增强各期病变及其周围软组织无明显强化.结论 骨化性肌炎影像表现具有一定特征,根据病程分析可更全面地显示其特点.     

Rice body formation in bicipito-radial bursitis: ultrasound, CT, and MRI findings

 The bicipito-radial bursa, which lies at the biceps tendon insertion on the radial tuberosity, is a rare site of chronic bursitis. We describe the clinical, radiological, and pathological findings in a case complicated by multiple rice body formation. In so doing, we describe MR appearances that allow discrimination of this entity from both synovial chondromatosis and pigmented villonodular synovitis.     

硬脊膜外脓肿的MRI诊断

目的 探讨ＭＲＩ对硬脊膜外脓肿的诊断价值。方法 回顾性分析经手术病理或细菌培养证实的１３例硬脊膜外脓肿的ＭＲＩ表现。结果 根据ＭＲＩ表现,硬脊膜外脓肿分为小脓腔（４例）、大脓腔（５例）、肉芽肿（２例）及纤维肉牙肿（２例）４型。病变均有占位效应,前３型病变在Ｔ２ＷＩ上与脊髓比较呈等低信号,其中残存形态不同的脂肪信号为其特征。增强扫描Ｔ１ＷＩ示大小脓腔不强化,脓肿壁、间隔及硬兴强化具有特征。肉芽肿型呈     

Spinal epidural abscess: correlation between MRI findings and outcome

Our purpose was to determine if specific MRI findings in spinal epidural abscess (SEA), at the time of diagnosis, are associated with the clinical outcome. The clinical records and MRI studies of 18 patients with SEA were reviewed and follow-up was obtained from the outpatient medical record, telephone interview, or both. The association between findings on contrast-enhanced MRI and clinical outcome (weakness, neck or back pain, and incomplete functional recovery) was evaluated. With univariate analysis, narrowing of 50 % or more of the central spinal canal (P = 0.03), peripheral contrast-enhancement (P = 0.05), and abnormal spinal cord signal intensity (P = 0.05) were associated with weakness at follow-up. Persistent neck or back pain was associated with spinal canal narrowing (P = 0.02), peripheral contrast-enhancement (P = 0.02), and an abscess longer than 3 cm (P = 0.04) on MRI. Incomplete clinical recovery was associated with both abscess length (P = 0.01) and the severity of canal narrowing (P = 0.01). Abscess length, enhancement pattern, and severity of canal narrowing can be incorporated in a grading system that can be used to predict outcome. Received: 9 September 1998 Accepted: 6 March 1999     

包膜期脑脓肿的MRI表现与病理分析

目的：分析包膜期脑脓肿的MRI表现，方法：经手术或临床抗炎治疗证实的包膜期脑脓肿18例，男14例，女4例，年龄，8－65岁，所有病例均行平扫及增强MRI检查，结果：所有病例脓肿壁上均有一光滑的低信号“暗带”，增强扫描见脓肿壁呈厚度均匀的不环形强化，强化环周围可见云絮状强化区。9例手术患者包膜上的“暗带”对应于病理上脓肿壁第3带的胶原包膜及丰富的巨噬细胞。5例经内科治愈的病灶其低信号“暗带”随访消失。结论：包膜期脑脓肿的MRI表现有一定的特征，其中“暗带”最具特征。     

Intracranial hemorrhage: ultrasound, CT and MRI findings

Intracranial hemorrhage is one of the most common causes of acute focal neurologic deficit in children and adults. Neuroimaging including ultrasonography (US), computer tomography (CT) and magnetic resonance imaging (MRI) is essential in the diagnosis of intracranial hemorrhage. Imaging findings should guide treatment. The highly variable appearance of an intracranial hemorrhage can be challenging. A thorough knowledge of hematoma evolution and US, CT and MR hematoma characteristics is mandatory for adequate interpretation of findings. The purpose of this review is (1) to summarize the imaging characteristics of intracranial hemorrhage on various imaging techniques and (2) to review the various types of intracranial hemorrhage, and their causes.     

Renal abscess with paranephric extension in a gravid woman: ultrasound and magnetic resonance imaging findings

We present a case of renal abscess with perinephric and paranephric extension. Ultrasonography showed an intrarenal lesion. The extension into the perinephric and paranephric space was better defined on MRI.     

Primitive neuroectodermal tumour of the prostate gland: ultrasound and MRI findings

We report a rare case of primitive neuroectodermal tumour (PNET) of the prostate occurring in a 26-year-old man with a mass replacing the prostate gland in the absence of any lesion involving the bone and soft tissues. To our knowledge, there is no radiological literature that has described the imaging findings in a case of PNET of the prostate. Imaging findings in cases of PNET of the kidney are described in the literature. On ultrasound, the mass appeared multilobulated and multinodular with intratumoural heterogeneity. No brightly reflective echoes with posterior acoustic shadowing to suggest calcification were noted. MRI revealed a heterogeneous lobulated mass with irregular septae within. The mass showed low signal intensity on T(1) weighted images and appeared heterogeneous on T(2) weighted images. Haemorrhage and necrosis were also seen in the tumour.     

脓肿期浆细胞性乳腺炎的MRI表现及与手术对照研究

目的:探讨脓肿期浆细胞性乳腺炎的MRI表现及其在临床诊疗中的应用价值。方法:收集经手术病理证实为脓肿期浆细胞性乳腺炎患者30例,术前均行双乳MRI平扫及增强扫描,分析其MRI表现,并与手术结果进行对照。结果:30例均为单侧发病,其中左乳21例,右乳9例。MRI示2个(6.7%)患乳内病灶局限于乳晕周围、5个(16.7%)累及单个象限及乳晕区、17个(56.7%)累及多个象限及乳晕区、4个(13.3%)累及单个象限、2个(6.7%)累及多个象限,其中15个(50%)累及乳后间隙。23个(76.7%)患乳病灶呈非肿块样,7个(23.3%)呈肿块样。采用切开扩创术3例、切开扩创术+象限切除术21例、象限切除术6个,1例切开扩创术后效果欠佳再次行切开扩创术+象限切除术,1例切开扩创术+象限切除术后效果欠佳再次行象限切除术。结论:MRI能清晰显示脓肿期浆细胞性乳腺炎病变的位置、累及范围及深度、皮下及病灶间的瘘管,具有一定特征性,与手术所见具有较高的一致性,对临床手术方案的制订有重要参考作用。     

Hyperplastic callus formation in osteogenesis imperfecta: CT and MRI findings

Hyperplastic callus formation is a noteworthy condition in patients with osteogenesis imperfecta because it often mimicks osteosarcoma on radiography. The findings of CT and MRI in hyperplastic callus formation have not been reported. In the presented case, MRI demonstrated contrast enhancement and edema of the surrounding soft tisssue, consistent with benign as well as malignant disease. Computed tomography showed a calcified rim of the lesion which may be a useful feature to rule out osteosarcoma in this condition. Received 7 August 1997; Revision received 17 November 1997; Accepted 24 December 1997     

Iliopsoas myositis mimicking appendicitis: MRI diagnosis

 Myositis of the truncal muscles can closely mimic acute appendicitis. Myositis is the early stage of muscular infection. It is characterized by diffuse muscular pain and swelling without a distinct mass. Early diagnosis of myositis improves the outcome and surgical debridement is usually avoided. Pyomyositis, the advanced stage of the disease, can be diagnosed by MRI examination. We present a case of early bacterial myositis that was diagnosed by MRI.