MR imaging of syringohydromyelia and Chiari malformations in myelomeningocele patients with scoliosis

The brain and spinal cord were examined with MR imaging in 30 myelomeningocele patients 3-32 years old to study the prevalence of syringohydromyelia and Chiari malformations and to correlate these conditions with developmental scoliosis and spontaneously arrested hydrocephalus. Twelve patients had neurologic deficits above the level of the myelomeningocele and 10 had spontaneously arrested hydrocephalus. MR visualized syringohydromyelia in four patients with widened or focally bulging spinal cords and in eight patients with atrophic spinal cords. All patients had Chiari malformations, 28 of type II and two of type I. Syringohydromyelia was not correlated with type of scoliosis, result of ventriculoperitoneal shunting procedures, radiologic level of the myelomeningocele, or extent of the Chiari malformation. The two patients with the most rapid progression of thoracic scoliosis had the most extensive syringohydromyelia and radiologically low lumbar levels. Neurologic deterioration due to syringohydromyelia and Chiari malformations is probably more common in myelomeningocele than has been recognized previously and may cause developmental scoliosis, loss of ambulation, impaired extremity function, and progressive cranial nerve paralysis.     

MR imaging of the spine in children

MR imaging was reviewed in 66 pediatric spinal cord patients with diagnoses of posterior fossa tumor (n = 8), primary spinal cord tumor (n = 3), metastatic disease (n = 11), neuroectodermal disorder (n = 8), congenital malformation (n = 14), trauma (n = 2), and demyelinating, neurodegenerative, or metabolic disorders (n = 9). MR proved to be useful in delineating the extent of posterior fossa and cord tumor including metastasis to the cord. MR was of limited value in demyelinating and metabolic disorders. Arnold Chiari malformations, syringomyelia, tethered cord and meningoceles were all easily evaluated using MR.     

MR imaging of syringomyelia and hydromyelia

The relative effectiveness of plain computed tomography (CT), metrizamide CT, conventional myelography, and magnetic resonance (MR) imaging was compared for the examination of cystic spinal cord lesions. Intramedullary cavities in 18 patients were demonstrated by MR imaging: cavities were uncomplicated in 13 patients, associated with spinal tumors in two, and studied after occipital craniectomy for treatment of Chiari malformation and syringomyelia in two. Cavities were shown by MR imaging in all enlarged spinal cords, but a cavity was shown in only one of four small cords. The rostral limits of the cavities were demonstrated better than were the caudal extensions. Ventricular communication was not demonstrated. Chiari malformation was shown only in cavities that did not involve the medulla. Syringes associated with tumor were indistinguishable from uncomplicated cavities, but the tumor had abnormal signal on long spin-echo sequences in two cases. Cystic cord tumor (one case) had an inhomogeneous appearance. Caudal displacement of the cerebellar hemisphere through the surgical defect associated with compression of the fourth ventricle was shown in two cases after posterior fossa craniectomy. Thirteen patients were studied with metrizamide CT also. MR imaging proved to be as accurate as metrizamide CT in the diagnosis of intramedullary cavities that result in spinal cord enlargement, but it was less sensitive in detecting cavities within normal-sized or diminished spinal cords. It had the advantage that tumor tissue could be distinguished from associated syrinx cavities by differences in signal characteristics; and cerebellar ectopia was evaluated easily on sagittal MR views.     

Exophytic syrinx, an extreme form of syringomyelia: CT, myelographic, and MR imaging features.

Magnetic resonance (MR) imaging and computed tomography (CT) were used to study severe syringomyelia, in which the syrinx was so eccentric relative to the center of the spinal cord that at initial examination it appeared to be an exophytic extramedullary mass, in five of six patients with type 2 Arnold-Chiari malformation and one patient with an intramedullary tumor. Sagittal and axial images were routinely obtained at 1.5 T; CT was performed after intrathecal injection of contrast material. On sagittal MR images, the exophytic component of the syrinx typically displaced the spinal cord peripherally and mimicked an extramedullary intradural lesion such as an arachnoid cyst or meningioma. On axial MR images, the gradual appearance and disappearance of this component could be traced as it compressed the spinal cord, which had a signet-ring appearance at the equator of the syrinx. It is concluded that both MR imaging and postmyelographic CT can reveal the characteristics of this lesion on axial images, but MR imaging is superior because it enables direct sagittal imaging.     

Spinal cord schistosomiasis: MR imaging appearance with surgical and pathologic correlation

BACKGROUND AND PURPOSE: Spinal cord involvement is a rare manifestation of schistosomiasis. We describe the MR imaging findings of spinal cord schistosomiasis in correlation with surgery and pathology. METHODS: We report eight cases of spinal cord schistosomiasis. All patients were men (mean age, 16.7 years) with neurologic manifestations who had been referred for spinal MR imaging. In all cases, spinal masses were surgically removed. MR imaging findings were correlated with surgery and pathology. RESULTS: MR imaging showed moderate expansion of the distal spinal cord in all cases. Abnormalities were isointense to cord in T1 and patchy hyperintense in T2-weighted spin-echo images (n = 8). Three forms of contrast enhancement were recognized: (1) intramedullary nodular (n = 8); (2) peripheral (n = 8); and (3) linear radicular (n = 4). Total gross surgical removal of masses by using the Cavitron ultrasonic surgical aspirator was possible in six cases. Diagnosis was established by identification of ova in histopathologic studies: Schistosoma mansoni (n = 3), S. hematobium (n = 1), and uncertain species (n = 4). Intramedullary nodular enhancement was correlated to multiple schistosomiasis microtubercles. Peripheral enhancing lesions correlated to thickened leptomeninges infested by chronic granulomatous inflammatory cells and schistosoma eggs. Linear radicular enhancement correlated with thickened resected nervous roots infested by granulomatous cells and schistosoma eggs. CONCLUSION: Multinodular intramedullary contrast enhancement of the distal cord enabled correct presumptive preoperative MR imaging diagnosis of spinal schistosomiasis in three cases. Accurate diagnosis, through recognition of its MR imaging appearance, allows early treatment and better prognosis of spinal cord schistosomiasis.     

Acute cervical spine trauma: evaluation with 1.5-T MR imaging

Twenty-one patients with acute neurologic deficits following cervical spine trauma were evaluated with magnetic resonance (MR) imaging (n = 21), computed tomography enhanced with intrathecal contrast material (CT myelography) (n = 18), myelography (n = 13), cervical spine radiography (n = 21), and intraoperative sonography (n = 7). MR imaging proved superior to other modalities in demonstrating parenchymal spinal cord injuries and cervical intervertebral disk herniation. Although both T1- and T2-weighted studies appear necessary to evaluate the anatomic relationship of the spinal cord, thecal space, intervertebral disks, and surrounding osseous and ligamentous structures, T2-weighted sequences were more sensitive than T1-weighted studies for detection of spinal cord injury. CT myelography was superior to MR imaging in demonstrating cervical spine fractures. In most cases, myelography revealed no information that was not apparent from both CT and MR imaging studies. Preliminary experience with MR imaging of acute cervical spine trauma suggests that it should be the study of choice in symptomatic patients who are otherwise clinically stable. CT may still be required in selected patients to evaluate complex fractures.     

MR-pathologic comparisons of wallerian degeneration in spinal cord injury.

PURPOSETo describe the MR manifestations and temporal course of wallerian degeneration that occurs above and below a spinal cord injury, and to compare the MR findings with postmortem histopathology.METHODTwenty-four postmortem spinal cords from patients with cervical (n = 14), thoracic (n = 6), and lumbar (n = 4) cord injuries were studied with axial T1- and T2-weighted spin-echo MR imaging. Injury-to-death intervals varied from 8 days to 23 years. The images were examined for alteration of signal above and below the injury site. Histologic studies of these cords with axon, myelin, and connective tissue stains were performed at levels equivalent to the MR sections. Immunohistochemical analysis using antibodies to glial fibrillary acetic protein was also performed on 19 cords. Pathologic-imaging comparisons were made.RESULTSMR images showed increased signal intensity in the dorsal columns above the injury level and in the lateral corticospinal tracts below the injury level in all cases in which cord injury had occurred 7 or more weeks before death. In early postinjury survival times (8 days and 12 days) MR findings were normal; histologically there was early wallerian degeneration in only the dorsal columns at 8 days and in both the lateral and dorsal columns at 12 days. MR showed wallerian degeneration in all cases examined at 7 weeks after injury and thereafter.CONCLUSIONSWallerian degeneration was demonstrated by histology and MR in all specimens in which the injury-to-death interval was greater than 7 weeks. Recognition of wallerian degeneration on MR allows complete analysis of the injury, explains abnormal MR signals at sites remote from the epicenter of the injury, and may be useful in the future in the timing and planning of therapeutic interventions.     

Conventional and CT metrizamide myelography in Arnold-Chiari I malformation and syringomyelia

Four normal controls and 26 cases of Arnold-Chiari I malformations and/or syringomyelia were reviewed. The pathologic cases included five isolated Arnold-Chiari I malformations, nine communicating syringomyelia, five idiopathic syringomyelia, four posttraumatic syringomyelia, one syringomyelia with hemangioblastoma, and two postshunt syringomyelia. The objectives of this study were to compare the accuracy of conventional metrizamide myelography with CT metrizamide myelography and to study indirectly the hydrodynamics of CSF flow in syringomyelia by comparing the sequential enhancement patterns of the spinal cords and cord cavities in the different groups of patients. Twenty-five patients underwent conventional metrizamide myelography immediately before CT metrizamide myelography, and one patient underwent CT metrizamide myelography only. Scans were obtained 1-2 hr, 4-8 hr, and 12-24 hr after injection of metrizamide, but not all patients were scanned during all three intervals. CT metrizamide myelography was found to be more sensitive than conventional metrizamide myelography in the diagnosis of both Arnold-Chiari I malformation and syringomyelia. Performing just an immediate and a delayed scan was found to be more cost-effective than doing all three scans. Contrary to previous reports, it was found that delayed (12-24 hr) scans demonstrated more syrinx cavities than intermediate ones. In studying the sequential enhancement patterns of the spinal cords and cord cavities, some interesting trends were observed that tend to support the theories of Aboulker and of Ball and Dayan of transneural passage of CSF into cord cavities in syringomyelia.     

Delayed neurologic deterioration in the patient with spinal trauma: role of MR imaging.

PURPOSE: To 1) correlate spinal MR features and modes of clinical presentation associated with symptomatic neurologic deterioration following longstanding spinal trauma; 2) correlate degree of neurologic deficit with spinal MR appearance in these patients; and 3) determine the relationship between new symptoms and ongoing cord compression. METHODS: Retrospective examination of MR images, and correlation with clinical data, in 94 consecutive patients. RESULTS: Sixty-seven patients presented with either an increase in degree of myelopathy or ascending neurologic level. Spinal cord atrophy (43%), syrinx (41%), and cord compression (24%) were found most frequently. Whereas in patients with complete motor and sensory deficit cord atrophy was the most frequent finding (52%), 75% of patients with useful motor function had normal spinal cords. There was a significant association (P less than .05) between cord compression and the MR findings of cord atrophy and myelomalacia, whereas a normal cord was over twice as frequent in patients without spinal cord compression. MR imaging led to an active change in management in 15% of patients, with improvement following surgery in all operated cases. CONCLUSION: Although syrinx is a frequent, and treatable cause of delayed neurologic deterioration, MR will frequently show other abnormalities such as ongoing cord compression. MR imaging should be performed urgently in all patients with new symptoms to enable early treatment to prevent irreversible loss of function.     

脊髓血管畸形的MRI诊断价值

目的 评价MRI对脊髓血管畸形的诊断价值。资料与方法 24例临床诊断为脊髓占位的患者行MR平扫、增强、3D-CISS和三维增强磁共振血管成像(3D-CE-MRA)。结果 24例中23例可显示畸形血管：髓内3例，髓外16例，髓内外4例。对供血动脉、引流静脉的显示MR平扫不及3D-CE-MRA。1例MRI显示硬膜下血肿，未见畸形血管。结论 MR平扫是脊髓血管畸形最敏感的首选检查方法，3D-CE-MRA有助于脊髓畸形血管的显示。     

Acute cervical spine trauma: correlation of MR imaging findings with degree of neurologic deficit

A retrospective analysis of magnetic resonance (MR) imaging studies of 78 patients with acute cervical spinal cord injuries was undertaken to determine which observations related directly to the neurologic injury. All MR imaging studies were performed on a 1.5-T unit and assessed with respect to 14 parameters related to the bony spine, ligaments, prevertebral soft tissues, intervertebral disks, and spinal cord. Forty-eight patients also underwent non-contrast material-enhanced thin-section computed tomography (CT) of the cervical spine. MR imaging was the definitive modality in the assessment of soft-tissue injury, especially in the evaluation of the spinal cord and intervertebral disks. All patients with a neurologic deficit had abnormal spinal cords at MR imaging. Intramedullary hemorrhage was predictive of a complete lesion. The degree of associated bone and soft-tissue injury had no bearing on the extent of spinal cord injury or neurologic deficit. Patients with residual cord compression following reduction demonstrated greater neurologic compromise than those without compression.     

磁共振3D重建技术在脊柱侧弯中的应用

目的:探讨磁共振3D重建技术在脊柱侧弯中的应用价值。方法:对16例脊柱侧弯的患者,在磁共振扫描中,采用自旋回波T1WI及快速自旋回波T2WI序列,扫描完成后,将各序列分别进行3D重建,在1幅图像上显示整个脊柱及椎管内脊髓全貌。结果:16例均可在1幅图像上完整显示扭曲的脊柱及椎管内脊髓全貌,了解脊柱侧弯的程度,椎管内脊髓受压变形改变及脊髓内的病变和其完整的范围。结论:磁共振3D重建技术的应用,准确直观的诊断了脊柱畸形病变,对临床治疗和手术方案的制定有比较大的指导作用。     

MR imaging of acute spinal cord trauma

The thoracic spinal cords of five mongrel dogs were imaged with a 1.5 T MR scanner before and after trauma induced by a well-established method of spinal cord impaction that produces central cord hemorrhagic necrosis. The anesthetized dogs were studied acutely with a 5-in. circular surface coil, 12-cm field of view, sagittal and axial partial-saturation (TR = 600, TE = 25 msec) and spin-echo (TR = 2000, TE = 25-100 msec) techniques. One normal dog was used as a control. The cords were surgically removed and histologically examined. Direct correlation of the pathologic findings and imaging data showed that at the level of trauma there was obliteration of epidural fat and CSF spaces secondary to central cord hemorrhage and edema. The traumatized cords expanded to fill the bony canal, and there was loss of visualization of the internal anatomy of the cord (gray- and white-matter structures). We conclude that MR can accurately identify cord hemorrhage and edema within a few hours of spinal trauma.     

Tumors and arteriovenous malformations of the spinal cord: assessment using MR

Thirty-three patients with either primary spinal cord tumors (n = 18), intradural tumors excavating into the cord (n = 9), or spinal arteriovenous malformations (AVM) (n = 6) were studied with magnetic resonance (MR) imaging. In 25 of 38 examinations (66%) (five patients were studied twice), MR provided more information than that provided by other neuroradiologic procedures. In several cases, MR affected patient management decisions. Advantages of MR, in addition to the absence of ionizing radiation and its noninvasive nature, include good spinal cord-CSF-theca contrast, lack of bone-derived artifacts, ease of multiplanar imaging, improved discrimination between intra- and extramedullary lesions, better definition of tumoral cavities and possible distinction from true syringes, ability to help one recognize thrombus formation within an AVM, and ease of follow-up of cord lesions for possible size changes. Apart from factors precluding the study in several patients (life support systems, pacemakers, claustrophobia, neurovascular clips), disadvantages of MR imaging include motion artifacts (prevalent in thoracolumbar area), poor capability of typing and grading of tumors, potential of false-positive results, poor detection of calcification, and poor delineation of feeders and drainers of AVM.     

Acute spontaneous spinal epidural hematomas.

BACKGROUND AND PURPOSE: Although previous reports have characterized MR imaging features of spinal epidural hematomas (EDH), few cases have been reported during the acute or hyperacute phase within the first 48 hours. Our goal in this investigation was to correlate the MR imaging features of acute (< or =48 hours) spontaneous EDH with clinical management and outcome. METHODS: Eight patients with acute spontaneous EDH (five men and three women; age range, 31-81 years) underwent MR imaging at 1.5 T (T1-weighted, n = 8; T1-weighted after the administration of 0.1 mmol/kg contrast material, n = 6; T2-weighted, n = 8; and T2-weighted, n = 4). The interval from symptom onset to hospital admission ranged from immediate to 5 days. Two neuroradiologists reviewed the MR images for signal characteristics, contrast enhancement, and cord compression. Treatment and clinical outcome were correlated with the imaging findings. RESULTS: The EDH were located in the cervical (n = 3), cervicothoracic (n = 2), thoracolumbar (n = 2), and lumbar (n = 1) regions. On T1-weighted images, the signal intensity of the EDH was isointense to spinal cord in five cases, hyperintense in two cases, and hypointense in one case and did not correlate with time to imaging. Isointensity on T1-weighted images persisted for 5 days in one case. On T2-weighted images, all EDHs were hyperintense with focal, heterogeneous hypointensity. Cord compression was severe in six patients, moderate in one patient, and minimal in one patient. Four cases were treated conservatively with complete resolution or improvement of symptoms within 1 to 3 weeks. CONCLUSION: MR imaging findings were useful in establishing the diagnosis of EDH but did not influence management or predict outcome in this series. Heterogeneous hyperintensity to cord with focal hypointensity on T2-weighted images should suggest the diagnosis of acute spinal EDH. Severity of neurologic impairment had the greatest impact on management and outcome. Nonoperative treatment may be successful in cases with minimal neurologic deficits, despite cord compression revealed by MR imaging.     

脊髓栓系综合征的MRI诊断

目的　探讨脊髓栓系综合征 (TCS)的MRI特点及诊断价值。方法　对 30例TCS患者的MRI资料进行了回顾性分析 ,所有病例均经手术病理证实。结果　 30例中 ,脊髓圆锥尖部位置均低于L2 椎体中部以下 ,脊髓受牵拉固定 ;单纯终丝粗大紧张 4例 ,约占 13%;脂肪堆积 13例 ,约占 43%;脊膜膨出 4例 ,约占 13%;脊膜脊髓膨出 3例 ,占 10 %;椎管内肿瘤 6例 ,占 2 0 %,其中神经纤维瘤 2例 ,皮样囊肿 2例 ,表皮样囊肿 1例 ,畸胎瘤 1例。结论　MRI的优良的软组织分辨率、多方位成像等优点 ,能明确显示脊髓圆锥的位置 ,形态及伴发畸形 ,对诊断TCS具有重要价值。     

Spinal vascular malformations: MR angiography after treatment

PURPOSE: To evaluate the role of magnetic resonance (MR) angiography in the assessment of spinal vascular malformation therapy. MATERIALS AND METHODS: Thirty-four patients with spinal vascular malformations (30 dural arteriovenous fistulas, two perimedullary arteriovenous fistulas, and two intramedullary arteriovenous malformations) underwent MR angiography and MR imaging before and after endovascular or surgical treatment. RESULTS: MR angiography showed residual flow in perimedullary vessels in seven patients with dural fistula after embolization with liquid adhesive. In all seven, treatment failure was confirmed with arteriography. Long-lasting disappearance of flow in perimedullary vessels was demonstrated at MR angiography in 22 patients with dural fistula. MR imaging demonstrated normalization of spinal cord volume in 16 of 22 patients and signal intensity on T2-weighted images in three patients. Disappearance of cord enhancement was observed in five of 21 patients and of perimedullary enhanced vessels in six of 13 patients. In one additional patient with dural fistula treated with embolization, early posttreatment MR angiography showed disappearance of flow in perimedullary vessels, which reappeared at follow-up and was consistent with reopening of a small residual fistula. Posttreatment MR angiography demonstrated transient reduction of flow in the nidus in two patients with intramedullary malformations treated with embolization. Permanent disappearance of flow in the perimedullary vessel was seen after endovascular treatment in two patients with perimedullary fistula. CONCLUSION: MR angiography is more sensitive than MR imaging in depicting residual or recurrent flow in peri- or intramedullary vessels, which indicates patency of the vascular malformation.     

Prediction of neurologic outcome in acute spinal cord injury: the role of CT and MR.

PURPOSE: 1) To determine whether MR appearances of the spinal cord in acute trauma correlate with clinical prognosis, and 2) to identify other MR and CT prognostic factors in acute spinal trauma. METHODS: Retrospective evaluation of MR, CT, and clinical examinations in 32 acute spinal trauma patients examined between 1987 and 1990. RESULTS: All 21 patients with abnormal spinal cords on MR had complete motor paralysis at presentation, compared to only three of 11 patients with normal cords. Whereas cord transection and hemorrhagic contusion had poor prognoses, 73% of patients with cord edema and 100% of patients with normal cord had useful motor function at outcome. At follow-up MR, areas of cord contusion developed into cysts, while edema resolved, leaving residual areas of myelomalacia. Associated spinal fractures, ligament injury, and cord compression were associated (P < .05) with a worse prognosis. Spondylotic changes were a significant risk factor for spinal cord injury, mediated by cord compression. CONCLUSIONS: MR and CT are valuable techniques for quantifying injury and predicting prognosis in acute spinal trauma.     

脊髓空洞症在MRI表现(附123例分析)

目的：根据脊髓空洞症MRI的表现将其分类并观察其特点与疗效情况.方法：对123例脊髓空洞症患者（保守治疗观察81例、手术42例）临床及MRI表现进行病因分析.结果：123例脊髓空洞症患者中有66例单纯合并小脑扁桃体下疝,12例合并小脑扁桃体下疝及颅底发育畸形,3例合并小脑扁桃体下疝及纵裂畸形,3例合并脊椎侧弯及后凸畸形,9例合并脊髓脊膜彭出;11例合并肿瘤;12例有外伤史、其中6例脊椎骨折;7例合并脊髓拴系、圆锥低位.结论：MRI能直观全面显示脊髓空洞症范围和程度以及致病原因,为治疗提供指导性建议.     

Spinal abnormalities in pediatric patients: MR imaging findings compared with clinical, myelographic, and surgical findings

Eighty-one pediatric patients with a variety of spinal disorders, including suspected dysrhaphism, scoliosis, neoplasia, and neurofibromatosis, underwent magnetic resonance (MR) imaging. The results were retrospectively compared with those of myelography followed by computed tomography (CT) and surgery. In patients with dysrhaphism, most abnormalities, including hydromyelia, inclusion tumors, and sites of cord tether, were demonstrated with MR imaging. Diastematomyelia and small hydromyelic cavities were indistinguishable on routine coronal and sagittal T1-weighted images; axial images with T2 weighting were optimal for this differentiation. MR imaging did not enable direct visualization of a thickened filum or evaluation of tethering with a thin, dorsally positioned neural placode. Congenital or severe scoliosis required lengthy studies with multiple planes of imaging or myelography and CT. Milder curvatures were readily evaluated with MR imaging, and neoplastic lesions, with the exception of intrathecal tumor seeding, were adequately defined.