Contrast enhancement patterns of acute spinal epidural hematomas: a report of two cases

The MR finding of an acute spinal epidural hematoma (SEH) can mimic epidural neoplastic or inflammatory lesions, because acute SEH appears hypointense on T1-weighted images and hyperintense on T2-weighted images. We report on two cases of acute SEH with unusual contrast enhancement patterns on MR images. Contrast enhancement can be an MR finding of acute SEH, especially in bleeding diathesis, which indicates an active lesion that needs early diagnosis and management.     

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。     

MR demonstration of a unilateral olivary hypertrophy caused by pontine tegmental hematoma

Summary Two patients with unilateral olivary hypertrophy (OH) following a pontine tegmental hematoma are presented. Both showed palatal myoclonus and one patient showed an extremity myorhythmia on the opposite side of OH. the magnetic resonance (MR) examination demonstrated an abnormal unilateral hyperintense lesion in the ventral part of medulla oblongata on T2-weighted images. The MR findings were highly suggestive of the pathological nature of the lesion, showing the value of MR.     

MR imaging in the diagnosis of spontaneous spinal epidural hematomas

Three patients with spontaneous (idiopathic) spinal epidural hematomas were diagnosed with magnetic resonance (MR) imaging. Magnetic resonance is an accurate, rapid method of localizing and characterizing the hematomas. We believe that MR (where available) should be the primary method of diagnosis in cases in which spinal epidural hematoma is suspected.     

Computed tomography of spinal epidural hematoma

Three cases of spinal epidural hematoma are presented. Computed tomography (CT) was the first diagnostic method used in two patients and demonstrated a surgically confirmed spinal epidural hematoma in both patients. In a third patient who presented with a complete block on myelography, CT was helpful in assessment of the extent of the lesion and suggested a vertebral hemangioma as the cause of the hematoma. CT is a very useful tool in the diagnosis of spinal epidural hematomas.     

硬膜外麻醉神经并发症的MRI表现

目的探讨硬膜外麻醉神经并发症的MRI诊断价值. 资料与方法对12例硬膜外麻醉出现神经并发症的MRI资料进行回顾性分析,重点观察椎管内结构的形态、MRI信号特征. 结果脊髓损伤4例,1例合并硬膜外血肿,表现为髓内条状长T1、长T2信号;单纯硬膜外血肿5例,表现为梭形或半月形T1、T2不均匀高信号;硬膜外脓肿3例,表现为硬膜后外方梭形或长圆形稍长T1、长T2信号,增强扫描脓肿壁明显强化.诊断结果与临床和术后诊断结果符合. 结论 MRI对硬膜外麻醉神经并发症诊断具有很大价值,宜作为首选方法.     

Traumatic cervical injuries in ankylosing spondylitis

PURPOSE: To demonstrate the importance of magnetic resonance (MR) and computed tomography (CT) in the evaluation of cervical traumas in patients suffering from ankylosing spondylitis. MATERIAL AND METHODS: Eleven patients with advanced ankylosing spondylitis were admitted to neurosurgical treatment after trauma to the neck region. All had neurological symptoms and were evaluated with plain X-ray, CT, and MR. RESULTS: CT with reformation sagittal and coronal plane was superior to plain X-ray films in demonstrating fractures and dislocations. MR was considered mandatory when evaluating changes in medulla and epidural hematomas, which were detected in 4 patients. The clinical outcome was poor in 5 patients and good in 6. The poorest outcome was seen in patients with cord contusion and epidural hematoma. CONCLUSION: We conclude that plain X-ray is of no greater importance in the acute phase of highest value in follow-up evaluation of the healing process and final position of the fractured vertebrae. Our protocol in the acute phase in traumatized ankylopoetic patients consists of lateral conventional X-ray, CT with reformatted images, and MR, the last-mentioned being important in detecting epidural hematoma that reduces the clinical outcome further if not removed. In our opinion, MR must be part of the radiological protocol following neck traumas in all patients with ankylosing spondylitis.     

自发性脊髓硬膜外血肿的MRI诊断(附4例报告)

目的：对自发性脊髓硬膜外血肿（ＳＳＥＨ）的ＭＲ和临床表现进行评价。材料与方法：本组包括１９９６年至１９９８年的３例ＳＳＥＨ患者,男３例,女１例,年龄３３～６１岁。４例患者均无外伤、血管损伤或凝血机制障碍等病史。均作ＭＲＩ检查并有手术病理证实。结果：在ＭＲ图像上,血肿分别位于硬膜外腔的左后、右后及正后方。其中１例为ＡＶＭ导致的有包膜的血肿,另１例的局部有椎间盘突出。Ｔ１加权能特征性地反映血肿随时间发生的信号变化而最有价值;１．５Ｔ高场强和轴位梯度回波的Ｔ２加权能很好地判断血肿的位置。结论：自发性脊髓硬膜外血肿是一少见病,ＭＲＩ是它的首选检查方法。应当注意的是,要获得理想的临床疗效,就必须做到诊断精确,并及时地手术治疗,解除脊髓压迫。     

Spinal epidural hemangiomas: various types of MR imaging features with histopathologic correlation

BACKGROUND AND PURPOSE: Because of the high vascularization of hemangiomas, preoperative misinterpretation may result in unexpected intraoperative hemorrhage and incomplete resection, which results in the persistence of clinical symptoms or recurrence. Our purpose was to analyze various MR imaging features of a spinal epidural hemangioma with histopathologic correlation. MATERIALS AND METHODS: After searching through the pathology data bases in 3 hospitals, we included 14 patients (9 male and 5 female; mean age, 38 years; age range, 2-62 years) with spinal epidural hemangiomas confirmed by surgical resection after MR imaging. Three radiologists reviewed the MR imaging in consensus and categorized the features into subtypes on the basis of histopathologic findings. RESULTS: We categorized the MR imaging features as follows: type A for a cystlike mass with T1 hyperintensity (2 cases, arteriovenous type with an organized hematoma), type B for a cystlike mass with T1 isointensity (3 cases, venous type), type C for a solid hypervascular mass (7 cases, cavernous type), and type D for an epidural hematoma (2 cases, cavernous type with hematoma). Types A and B had frequent single segmental involvement (4/5), whereas types C and D had multisegmental involvement in all. Regardless of MR types, lobular contour (8/14) and a rim of low T2 signal intensity (8/14) of the mass were common. T1 hyperintensity of the mass was occasionally seen (5/14). CONCLUSIONS: Spinal epidural hemangiomas can have various MR imaging features according to their different histopathologic backgrounds. In addition to common features such as solid hypervascularity, lobular contour, and a rim of low T2 signal intensity, T1 hyperintensity or multisegmental involvement may also be a clue in the differential diagnosis of a spinal epidural hemangioma.     

Delayed epidural hematoma after evacuation of a subdural hematoma

CT easily diagnoses epidural hematomas. The appearance of an epidural hematoma may be delayed by compression from a contralateral lesion. The possibility of a delayed epidural hematoma should be kept in mind in the presence of additional findings such as a skull fracture contralateral to the original lesion or decompression of the epidural hematoma into either the subgaleal or the subarachnoid space. We present a case in which an epidural hematoma declared itself after the evacuation of a contralateral subdural hematoma.     

急性期脑内血肿3.0T MR扩散加权成像表现

目的:探讨3.0T MR设备中平面回波扩散加权成像(EPI-DWI)和表观扩散系数(ADC)图对急性脑内血肿的诊断价值及与脑梗死的鉴别诊断能力。方法:对18例急性期脑内血肿患者行EPI-DWI检查,获得ADC图并与CT及常规MRI进行对比。同期选择发病时间、病变体积相近的急性脑梗死患者18例,比较急性期脑内血肿与脑梗死的MRI表现。结果:所有急性期脑内血肿在EPI-DWI及ADC图上均为混杂信号,尤其是较大血肿;不同大小血肿周边均可见低信号环。所有急性脑梗死病变均未见周边环状低信号。结论:血肿周边低信号环为急性期脑内血肿的特异性DWI表现,可资与急性脑梗死相鉴别。     

Acute spinal subdural hematoma: MR and CT findings with pathologic correlates.

PURPOSETo determine the MR and CT findings that characterize acute spinal subdural hematoma (ASSH).METHODSThe MR, CT, and clinical findings in three patients with surgically proved ASSH were reviewed and also correlated with the postmortem MR, CT, and cryomicrotome findings in three other patients, two with ASSH and one with an acute spinal epidural hematoma.RESULTSImaging findings in ASSH included: (a) hyperdense lesions on plain CT within the dural sac, distinct from the adjacent low-density epidural fat and silhouetted against the lower-density spinal cord and cauda equina, which it compressed; (b) lack of direct continuity with the adjacent osseous structures; (c) clumping, loculation, and streaking of blood within the dural sac on both MR and Ct; and (d) an inhomogeneous and variable signal intensity to the ASSH on all MR pulse sequences, but, nevertheless, a striking low signal intensity on T2-weighted spin-echo or T2-weighted gradient-echo to a major part of the ASSH because of deoxyhemoglobin. Plain CT was most helpful in compartmentalizing the hematoma.CONCLUSIONWhen MR and plain CT are obtained as complementary studies, they provide characteristic findings that allow the prompt diagnosis of ASSH.     

Spinal MR findings in continuous epidural analgesia without infection

BACKGROUND AND PURPOSE: Spinal epidural abscesses are major complications of epidural anesthesia, and their MR features have been reported. In patients receiving continuous infusion via an epidural catheter, MR findings may mimic those of spinal epidural abscess in the absence of infection. The purpose of this study was to assess the spinal MR findings associated with continuous epidural anesthesia. METHODS: Spinal MR findings in five consecutive patients receiving continuous epidural anesthesia were retrospectively evaluated. Axial and sagittal T1- and T2-weighted spin-echo and contrast-enhanced fat-suppressed T1-weighted spin-echo images were obtained. Infection was ruled out on microbiologic analysis three patients and on follow-up in two. Each lesion was evaluated for its MR signal intensity, location, extent, delineation, and enhancement pattern. In three patients, follow-up MR imaging was performed within 5-150 days, and the images were compared. RESULTS: Posterior epidural lesions were identified in all five patients. The lesions were isointense to hypointense relative to the spinal cord on T1-weighted images, isointense relative to CSF on T2-weighted images, and well enhanced on enhanced T1-weighted images. The anomalous enhancement involved two to seven vertebral bodies. In one patient, the enhanced lesion slightly compressed the spinal cord. On follow-up MR imaging, the epidural lesions decreased in two patients and did not change in one. CONCLUSION: Continuous epidural anesthesia can result in MR findings similar to those of epidural abscess, even in the absence of infection.     

Magnetic resonance of the brain: the optimal screening technique

Magnetic resonance (MR) images and computed tomograms of 25 patients with head trauma were compared. MR proved to be superior in many ways for demonstrating extracerebral as well as intracerebral traumatic lesions. Isodense subdural hematomas, which present a diagnostic dilemma on CT images were clearly seen on MR, regardless of their varying CT densities. In a case of epidural hematoma, the dura mater was shown directly as nearly devoid of signal on MR. Direct coronal images provided excellent visualization of extracerebral collections along the peritentorial space and subtemporal area. In a patient with intracerebral hematoma, CT failed to demonstrate residual parenchymal changes in a 3-month follow-up study, but MR clearly depicted the abnormalities. The superiority of MR over CT was also well illustrated in a patient with post-traumatic osteomyelitis of the calvarium.     

Magnetic resonance imaging evaluation of acute spine trauma

A comparison study of magnetic resonance imaging (MR), computed tomography (CT), and plain film evaluation of 113 consecutive spine trauma cases was conducted. The rate of true-positive findings (sensitivity) on MR was shown to be significantly higher than for CT or plain films in the evaluation of soft tissue or ligamentous injury (P<0.001). MR had a significantly lower rate of positive findings for fracture than CT (P<0.001) and was also shown to be significantly less sensitive for fracture than plain films (P<0.001). Spinal cord contusion, epidural hematoma, high-grade stenosis, and ligamentous or soft tissue injury were best evaluated with MR. MR, CT, and plain films are all important modalities for the evaluation of acute spine trauma. It is recommended that, after clinical examination, patients with spine trauma be evaluated first by plain film. If there is clinical or radiologic suspicion for acute spine injury, MR should be the next diagnostic procedure performed. If MR is positive for acute injury, CT may be indicated. CT best defines the extent of bony injury, and MR the extent of soft tissue injury, intrinsic spinal cord pathology, and extrinsic dural sac compression.     

自发性脊髓硬膜外血肿的MRI诊断

目的 探讨自发性脊柱硬膜外血肿MRI表现特征.方法 对9例自发性脊髓硬膜外血肿的MRI表现作回顾性分析,本组患者均无明显的外伤史,发病后4～24h行MRI检查5例,1～3天行MRI检查3例,5天行MRI检查1例.常规横轴面、矢状面T2WI、TIWI及T2 WI脂肪抑制技术.结果 血肿发生于颈段4例,胸段2例,颈胸交界部2例,腰段1例.9例均表现为脊髓硬膜外梭形,长度7～12cm.血肿位于脊髓正后方4例,脊髓右后方3例,脊髓左后方1例,脊髓正前方1例,脊髓不同程度受压移位,脊髓与血肿间见线条状低信号影.4～24h行MRI检查5例,于T2 WI上呈稍高信号3例,高信号1例,等信号1例;于T11WI上呈等信号3例,等低信号2例.1～3天行MRI检查3例,于T2WI上呈低信号1例,等信号1例,等低信号1例;于T1WI上呈等信号2例,等低信号1例.5天行MRI检查1例,于T2 WI上呈低信号;T1WI上呈稍高信号.9例中T2WI压脂上呈低信号3例,等信号4例,高信号2例.结论 MRI是诊断自发性脊髓硬膜外血肿的最佳检查方法,不仅可以清楚地显示血肿的部位及范围,而且可以清楚地显示血肿新旧程度.     

MR imaging of epidural hematoma in the lumbar spine

OBJECTIVE: To bring attention to the MR imaging appearance of epidural hematoma (EDH) in the lumbar spine as a small mass often associated with disk herniation or an acute event. This paper will show our experience with this entity and describe criteria for its MR imaging appearance. DESIGN AND PATIENTS: Thirteen cases of prospectively diagnosed EDH of the lumbar spine were compared with 12 cases of prospectively diagnosed prominent epidural extrusion. Our criteria were retrospectively evaluated by the two authors for their presence or absence in each case. The chi-square test for nominal data was applied. MR imaging criteria utilized to distinguish EDH from disk herniation at our institution include: (1) signal different from disk, (2) high signal on T1-weighted images, either centrally or peripherally, (3) teardrop- or egg-shaped mass, in the sagittal plane, (4) size greater than half the vertebral body height in a craniocaudal dimension, (5) primarily retrosomatic epidural location, (6) plasticity - the mass is seen to conform closely to the contours of bone (e.g., in the lateral recess), (7) little or no disk space narrowing unless associated with disc herniation. RESULTS: Chi-square analysis demonstrated each criterion to significantly differentiate between EDH and extrusion. Only six of 13 EDH cases went to surgery in spite of their relatively large size. Two of six patients were diagnosed as having epidural clot consistent with hematoma at the time of surgery. The four patients who were not diagnosed at surgery revealed only small disk herniations or fragments of disk. CONCLUSIONS: The occurrence of EDH is more frequent than previously suspected. Spontaneous EDH is frequently associated with disk herniation and acute events such as sneezing or coughing. Most cases of spontaneous EDH will resolve prior to surgery with only the minority becoming chronic in order to be seen at surgery as an encapsulated mass. MR imaging can reliably identify EDH and distinguish between EDH and large disk extrusions.     

Cervical epidural lipoblastomatosis: changing MR appearance after chemotherapy

Lipoblastomatosis is a locally infiltrative tumor of embryonic fat. We describe the MR appearance of cervical lipoblastomatosis with epidural extension. The initial MR study showed features of a soft-tissue mass; a subsequent MR examination, performed after chemotherapy, depicted the lesion as a typical lipoma of high signal intensity on T1-weighted images and of intermediate signal on T2-weighted sequences.     

Cervical spine fractures in ankylosing spondylitis: MR findings

Purpose: The purpose of this study is to evaluate the MR findings in patients with long-term ankylosing spondylitis (AS) and acute cervical spine fractures. Materials and methods: The magnetic resonance imaging (MRI) studies of five patients with AS and acute cervical spine fractures were retrospectively reviewed for the presence of cervical spine instability, spinal cord compression, and epidural hematoma. Results: Spinal fractures were unstable in all five patients. Three patients had neurological symptoms and abnormal signal within the spinal cord. All patients with neurological deficits had epidural hematomas posterior to the dural sac. Conclusion: MRI is useful for assessment of the integrity of intervertebral disks and spinal ligaments and, therefore, of the instability of the spinal fracture. MRI is mandatory in patients with neurological symptoms, especially in those with a symptom-free interval and those with neurological deterioration after established spinal cord injury, when suspicion for epidural hematoma is high. Electronic Publication     

非外伤性脊髓硬膜外血肿的MR诊断

目的　探讨非外伤性脊髓硬膜外血肿的MR表现特点及其鉴别诊断。方法　 14例非外伤性脊髓硬膜外血肿 ,男 9例 ,女5例 ,年龄 4～ 63岁 ,平均 41.3岁。所有病例均无明显的外伤史。常规行T1W矢状位 ,T2 W矢状位及横切位扫描 ,1例行MR增强扫描。结果　 14例非外伤性脊髓硬膜外血肿中 11例位于椎管背侧 ,3例位于椎管腹侧 ,呈新月状或长条带状 ,分别累及 3～ 12个脊髓节段 ,平均 5 .2个脊髓节段。血肿位于颈胸段 4例 ,位于胸段 3例 ,位于胸腰段 5例 ,位于腰段 2例。 10例血肿T1W及T2 W均呈较均质性高信号强度 ,3例血肿T1W及T2 W呈不均质性高信号强度 ,1例于T1W呈中等信号强度 ,T2 W呈较低信号强度。 14例中 1例于血肿内可见低信号的血管流空影 ,术后证实为动静脉畸形。血肿于T1W及T2 W与脊髓之间有一低信号带相隔 ,尤以T2 W显示最佳。 2例受压脊髓于T2 W呈高信号。 1例行MR增强扫描 ,血肿壁轻度强化。结论　MR是诊断非外伤性脊髓硬膜外血肿的最佳检查方法 ,不仅可以清楚地显示血肿的部位及范围 ,而且可以清楚地显示血肿新旧程度及脊髓受损的情况