自发性脊髓硬膜外血肿的MRI表现

目的 对自发性脊髓硬膜外血肿(SSEH)的临床及MRI表现进行分析。方法 搜集1994～2001年的8例SSEH患者，其中男5例，女3例，年龄16～50岁。8例患者均无外伤、血液病等病史，1例有高血压病史，于发病4h至3d后分别行MR检查。8例均经手术病理证实。结果 血肿发生于颈椎3例、胸椎2例、颈胸交界部2例、胸腰段1例；血肿位于硬膜外腔的侧后方或正后方，呈梭形，范围长短不一，境界清楚。其中1例血肿为血管畸形(AVM)所致，有2例局部伴有椎间盘突出。血肿信号随时间长短各有差异，在T1WI矢状面和冠状面7例表现为等信号，1例表现为略高信号；在T2WI矢状面和轴面，6例表现为混杂信号，2例表现为混杂高信号。结论 MRI对SSEH的定位、定性及鉴别诊断具有重要作用。     

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     

Spinal epidural cavernous hemangioma: MR findings

PURPOSE: Cavernous hemangiomas with a spinal epidural location are very uncommon vascular tumors in contrast to those in the vertebral body. The purpose of this study was to describe the radiologic findings, focusing on the MR studies, of spinal epidural cavernous hemangiomas. METHOD: Five pathologically proven cases of spinal epidural cavernous hemangioma were retrospectively reviewed. MR (n = 5) and CT (n = 1) were evaluated. RESULTS: The level was thoracic (n = 4) or lumbosacral (n = 1). The mass was located in the epidural space and showed paravertebral extension in all cases. It showed a lobulated contour in all cases and encircled the spinal cord partially with a larger posterior (n = 3) or anterior (n = 1) component in four cases. In all cases, the mass showed high signal intensity on T2-weighted images and homogeneous, strong enhancement. Adjacent bony erosion (n = 5) and intervertebral neural foraminal widening (n = 4) were common. CONCLUSION: Spinal epidural cavernous hemangioma shows characteristic MR findings of a lobulated contoured epidural mass partially encircling the spinal cord with a larger posterior component in the spinal canal, high signal intensity on T2-weighted images, and homogeneous, strong enhancement.     

椎管内硬膜外海绵状血管瘤的MR表现

目的 探讨椎管内硬膜外海绵状血管瘤R诊断价值。方法 回顾性分析3例经病理证实的椎管内硬膜外海绵状血管瘤的MR表现，并复习相关文献。结果 3例椎管内硬膜外海绵状血管瘤中，2例位于胸椎，1例位于颈胸椎。3例均沿脊椎纵轴生长，呈梭形或长条形；2例肿块“钳”状包绕，推挤相应水平的脊髓；3例均表现为T2WI高信号，钆喷替酸葡甲胺（Gd-DTPA)增强扫描呈均匀一致的明显强化；2例肿瘤侵犯，压迫相邻的椎间孔并使椎间孔扩大，且经椎间孔突出旁间隙，呈“哑铃状”外观。2例合并椎体血管瘤。结论 椎管内硬膜外海绵状血管是非常少见的椎管硬膜外肿瘤，MRI是诊断此病的最佳方法，并具有相对特征性表现。     

Vertex epidural hematoma - neuroradiological findings and management

Epidural hematomas occurring at the vertex are uncommon, and they can be difficult to diagnose by axial CT. We report a case of acute traumatic vertex epidural hematoma, which resolved spontaneously with time. We stress the importance of MR investigations in this diagnostic challenge.     

急性硬脊膜外血肿的MRI研究

目的 探讨急性硬脊膜外血肿(ASEH)的发病机制、MRI表现特征及鉴别诊断。方法 15例ASEH病人，男8例，女7例，平均37．8岁。5例有脊柱损伤史，1例有脊柱手术史，1例有腰硬脊膜穿刺史，其余8例无特殊病史。11例经手术证实，2例经CT引导穿刺抽吸治疗并证实，2例经临床相应检查及随访证实。所有病人均行矢状面SE T1WI和快速SE(FSE)或SE T2WI。12例行横轴面FSE T2WI，8例行SE T1WI。4例行SE T1WI增强扫描。结果 15例血肿共发生于18个脊柱节段，其中6例次(6／18)位于颈段、9例次(9／18)位于胸段、3例次(3／18)位于腰段。7例次(7／18)血肿位于硬膜囊前方，11例次(11／18)位于硬膜囊后方。血肿累及1～13个椎体高度，平均4．87个椎体高度。T1WI上，所有血肿与脊髓之间均显示有线样低信号区。T2WI矢状面和横轴面上，分别有4例(4／15)和8例(8／12)在血肿与蛛网膜下腔之间显示有低信号线。矢状面上13例(13／15)血肿呈长梭形，横轴面上均呈双凸镜形或半圆形。SE T1WI上，5例呈等T1信号，6例呈短T1信号，4例呈等、短T1混杂信号；T2WI上，5例呈短T2信号，10例呈短、长T2混杂信号。4例增强扫描无特异性。结论 ASEH的MRI表现具有特征性，可为诊断及鉴别诊断提供依据。     

Acute traumatic spinal epidural hematoma: imaging and neurologic outcome

The purpose of this study was to present MRI characteristics of traumatic spinal epidural hematomas (TSEHs) and to evaluate their effect on neurologic outcome. A retrospective analysis was performed of all 74 cases in which patients underwent emergent spinal MRI in the setting of acute trauma at our institutions Emergency Department between June 2002 and January 2003. MRI studies were evaluated for the presence of a TSEH. CT studies were evaluated for the presence of osseous trauma. Patient data were collected from medical records on the initial neurologic status at admission and at 6 months after injury. Twenty-seven of 74 patients had a spinal fracture and a TSEH. Twenty-five of 74 patients had a spinal fracture with no TSEH. Twenty-two of 74 patients had normal imaging studies. Six-month follow-up of neurologic status demonstrated no statistically significant difference in neurologic outcome between patients with spinal fractures and TSEH and those with spinal fractures but no TSEH. If a spinal fracture and abnormal neurologic exam are present, the neurologic outcome at 6 months is not worsened by the presence of a TSEH.     

Spontaneous intramural small-bowel hematoma: imaging findings and outcome

OBJECTIVE: Our aim was to review the imaging findings and outcomes of patients with nontraumatic spontaneous intramural small-bowel hematoma. MATERIALS AND METHODS: We retrospectively reviewed the records and radiologic studies of 13 patients with known intramural small-bowel hemorrhage. RESULTS: The mean age at presentation was 64 years. Sixty-two percent of patients had warfarin toxicity. The diagnosis was evident on CT performed in all patients. Small-bowel obstruction was present in 85% of patients, and biliary obstruction was present in 8%. A single hematoma was present in 85% of patients, and multiple hematomas were present in 15%. The jejunum was the most common site of the hematoma (69%), followed by the ileum (38%) and duodenum (23%). The hematoma extended into the cecum in 15% of patients. The estimated average length of the hematoma was 23 cm, and the shortest segment was 8 cm. Resolution of the hematoma was seen on CT as early as 1 week after onset. Eleven patients (85%) with non-extensive hematomas were dismissed from the hospital without any short- or long-term complications (mean follow-up, 35 months). Two patients with extensive hematomas involving more than half the length of the small intestine died. CONCLUSION: Spontaneous intramural small-bowel hematoma is rare. It occurs in patients who receive excessive anticoagulation with warfarin or who have some other risk factor for bleeding. CT characteristics include circumferential wall thickening, intramural hyperdensity, luminal narrowing, and intestinal obstruction. Early diagnosis is crucial because most patients are treated nonoperatively with a good outcome.     

Sinonasal organized hematoma: CT and MR imaging findings

BACKGROUND AND PURPOSE: Sinonasal organized hematoma (OH) is an uncommon, nonneoplastic benign condition that can be locally aggressive. The purpose of this work was to characterize the CT and MR imaging findings of sinonasal OH.MATERIALS AND METHODS: CT (n = 11) and MR (n = 10) images of 12 patients (9 men and 3 women; mean age, 41 years; range, 12–76 years) with pathologically proved sinonasal OH were retrospectively reviewed. Particular attention was put on the location, shape, size, extent, internal architecture, and enhancement pattern of the lesion and associated sinus wall change.RESULTS: The lesions were seen as an expansile (n = 9) or nonexpansile (n = 3) mass, ranging in size from 2.2 to 6.0 cm (mean, 4.2 cm), primarily involving the maxillary sinus (n = 11) or nasal cavity (n = 1) unilaterally. The ipsilateral nasal cavity was also involved in 9 of 11 maxillary sinus lesions. Smooth sinus wall erosion other than the medial maxillary sinus wall was noted in 8 lesions. The internal architecture was best displayed on T2-weighted MR images on which all of the lesions were seen as a mixture of marked heterogeneous hypointensity and isointensity, surrounded by a hypointense peripheral rim, reflecting histologic heterogeneity of the lesion composed of hemorrhage, fibrosis, and neovascularization. Marked irregular nodular, papillary, or frondlike enhancement at the areas of neovascularization was also a typical finding seen in all of the lesions.CONCLUSION: An expansile soft tissue mass, smooth sinus wall erosion, marked heterogeneous signal intensity with a hypointense peripheral rim on T2-weighted MR images, and marked irregular nodular, papillary, or frondlike enhancement are characteristic CT and MR imaging findings of sinonasal OH.

Sinonasal organized hematoma (OH) is an uncommon, nonneoplastic benign condition that can be locally aggressive. Without careful evaluation of all of the imaging features, this may be mistaken for a malignant lesion both clinically and radiologically. It most commonly affects the maxillary sinus and can result from various causes of hemorrhage with chronic hematoma formation, followed by the process of organization through fibrosis and neovascularization.^1,2 Since the first report by Ozhan et al³ in a patient with von Willebrand disease, only fewer than 40 cases have been reported in the English literature under various names, including pseudotumor,^3,4 hematoma,⁵ organized or organizing hematoma,^1,2,6–8 and hematoma-like mass of the maxillary sinus.⁹Correct preoperative diagnosis of sinonasal OH is important to avoid unnecessary extensive surgery, because this condition is curative with a simple, conservative surgical approach and rarely recurs. Although there have been a few reports on the CT findings of sinonasal OH,^1–3,5–9 which are reported to be rather nonspecific, to our knowledge, the MR imaging features have not systematically been analyzed previously. Only 2 studies had briefly mentioned the MR imaging features.^8,9 Yagisawa et al⁹ reported that masses were well demarcated from the surrounding structures and heterogeneous in signal intensity on both T1- and T2-weighted MR images. Song et al⁸ reported that the lesions appeared as isosignal intensity with a margin that had a slightly higher signal intensity on T1-weighted images and a mosaic of various signal intensities and a low signal intensity rim on T2-weighted images. The purpose of this study was to report the CT and MR imaging findings, which are believed to be characteristic for sinonasal OH.     

Vertex epidural hematomas: imaging findings and diagnostic pitfalls

PURPOSE: Our purpose was to show the computed tomography (CT) and magnetic resonance (MR) imaging features of vertex epidural hematomas (EDHs) and emphasize pitfalls in the diagnosis of this entity. SUBJECTS AND METHODS: The neuroradiologic studies of four patients (CT in four, MR imaging and MR venography in one) were evaluated for EDH shape, size and appearance. RESULTS: EDHs were biconvex in three patients and crescentic in one patient. CT appearances included a collection that was hyperdense (two patients), generally isodense with a few regions of hyperdensity (one patient) and mixed hyperdense and hypodense (one patient). MR imaging findings in one patient consisted of hyperintense signal on T1-weighted images and hypointense signal on T2-weighted images. Inferior displacement of the superior sagittal sinus was seen in two patients. Diagnosis of a small vertex EDH was difficult on routine axial CT in one patient, but apparent on MR imaging and MR venography. CONCLUSIONS: Small vertex EDHs can be difficult to diagnose on routine CT. MR imaging or thin section CT should be performed to exclude the diagnosis in patients with trauma to the skull vertex.     

Subacute sclerosing panencephalitis: relationship between clinical stage and diffusion-weighted imaging findings

PURPOSE: To investigate the relationship between clinical stages and apparent diffusion coefficient (ADC) changes in the brain of patients with subacute sclerosing panencephalitis (SSPE). MATERIALS AND METHODS: A total of 18 patients with stage II (N = 11) and III (N = 7) SSPE and 11 age-matched controls underwent routine MRI and diffusion-weighted imaging (DWI). The ADC values were automatically calculated. Seven distinct neuroanatomic structures (frontal, parieto-occipital, and cerebellar white matter; deep white matter; thalamus; basal ganglia; and brainstem) were selected for analysis in the patient and control groups. RESULTS: Hyperintensities in the periventricular and subcortical white matters on T2-weighted images and ADC maps were detected in 63.6% of patients with stage II and in all patients with stage III. There were significant differences between stage II and III patients and also between patients and control group in ADC values that obtained from all locations. The highest mean ADC values were calculated in stage III patients. Although MRI and DWI findings were normal in four patients with stage II disease, ADC values were significantly increased when compared with controls. CONCLUSION: The stage of disorder may be independent of DWI appearance during the early stage (stages I and II), even though the brain is affected. Therefore, DWI and ADC values supplemental to routine MRI should also be utilized for lesion detection and definition to enhance diagnostic accuracy in patients with SSPE.     

Spinal epidural extraskeletal Ewing sarcoma: MR findings in two cases

SUMMARY: We report the CT myelography and MR findings of two cases of extraskeletal Ewing sarcoma involving the spinal epidural and paravertebral spaces in a middle-aged man (case 1) and a young woman (case 2). In both cases CT myelography showed epidural and paravertebral masses on one side, with widening of the ipsilateral neural foramina at the C5-C6 level in case 1 and at the C7-T1 level in case 2. On MR images, the masses were isointense to muscle on T1-weighted images, hyperintense on T2-weighted images, and showed moderate enhancement on contrast-enhanced T1-weighted images. In one case, all pulse sequences showed linear signal voids, representing the vertebral artery encasement within the mass. The intradural component connected with the main mass was detected in the other case.     

Spinal epidural abscess: evaluation with contrast-enhanced MR imaging.

Seven patients with spinal epidural abscess were evaluated with MR imaging. T1-weighted images were obtained before and after administration of gadopentetate dimeglumine, and contrast-enhanced images were compared with available T2-weighted images and unenhanced T1-weighted images. In all seven cases, the epidural infection was iso- to hypointense compared with the spinal cord on unenhanced T1-weighted images, and increased in intensity on proton-density- and T2-weighted images. Three patterns of enhancement were observed after contrast administration. In three patients the infection enhanced homogeneously, likely representing thickened, inflammed tissue with microabscesses and granulomatous material. In one patient, peripheral enhancement surrounded a central focus of low signal intensity, representing necrotic abscess. In two patients, a combination of both patterns was observed. One abscess infiltrated the posterior thoracic epidural fat, producing decreased signal within the high-signal fat on T1-weighted images. Enhanced T1-weighted images were equivalent to unenhanced T2-weighted images in detecting the extent of epidural involvement in three cases. In two cases, enhanced T1-weighted images were superior to T2-weighted images in differentiating the infectious component from surrounding CSF. In one case, contrast administration produced no discernible enhancement. Enhanced images also provided important information regarding the composition of the abscess (liquid versus solid). Contrast-enhanced MR images are valuable in the characterization of spinal epidural abscesses.