Recurrent postdiskectomy low back pain: MR-surgical correlation

The preoperative MR findings in 11 patients, all of whom had developed recurrent low back pain after surgery for herniated lumbar intervertebral disk, were correlated with the surgical findings to determine possible criteria for distinguishing recurrent disk herniation from postoperative scar (extradural fibrosis). The preoperative MR findings agreed with the surgical findings in seven of eight patients with recurrent disk herniation and in six of nine individuals with extradural fibrosis. The most important parameters in differentiating recurrent herniated disk from extradural scar were the configuration and margination of the extradural mass rather than its signal characteristics. The most reliable MR sign for recurrent herniated disk was the presence of a sharply marginated focal polypoid disk protrusion beyond the posterior margins of the adjacent vertebral bodies shown to best advantage on sagittal T1- and T2-weighted and axial T1-weighted spin-echo MR images. Disk herniations usually maintained isointensity with the intervertebral disk of origin, while extradural fibrosis exhibited variable signal intensity. The preoperative diagnosis of extradural fibrosis on MR was based primarily on its irregular configuration and extension. This study suggests that preoperative differentiation between scar and recurrent herniated disk is possible with MR when morphology and topography are considered in addition to signal intensity.     

MR imaging of intradural disk herniation

The magnetic resonance findings in a case of lumbar intradural disk herniation are described and compared with myelography. Magnetic resonance was superior to myelography in visualizing all components of the herniation including adhesions and inflammatory tissue.     

Intradural chordoma: case report and review of the literature

Chordomas are rare neoplasms arising from notochordal remnants found predominantly in the clivus and the sacrococcygeal regions. Most clivus chordomas show extradural extension and bone destruction. Such a tumour can rarely be intradural. This report is concerned with the radiological findings in prepontine intradural chordoma.     

Imaging of spine neoplasm

Although most often back pain is of benign origin, it can occasionally be a harbinger of a more serious spinal condition, including spine neoplasm. Knowledge of the typical clinical history of spinal tumors and an understanding of the innervation of the spine and surrounding supporting structures may allow us to better understand when to pursue advanced imaging in the evaluation of spinal pain syndromes. Many radiologists have divided the differential diagnosis of neoplasms of the spine into compartments. These compartments include the extradural compartment, intradural/extramedullary compartment, and the intramedullary compartment.     

腰椎间盘术后症状复发的CT分析(附80例报告)

目的：分析腰椎间盘术后的ＣＴ改变，探讨术后症状复发的原因。材料与方法：本组８０例均行术前及术后ＣＴ扫描，其中１８例为术后脊髓造影ＣＴ扫描，１０例为术后ＣＴ增强扫描，有２０例经第二次手术证实ＣＴ所见。结果：术后ＣＴ所见主要有硬膜外纤维化、椎间盘突出复发或碎块残留、椎管狭窄、蛛网膜粘连等；硬膜外纤维化的程度与术式有密切关系；临床症状的轻重与ＣＴ的阳性征密切相关。结论：腰椎间盘术后症状复发的原因主要为硬膜外纤维化、椎间盘突出复发或碎块残留、椎管狭窄、蛛网膜粘连等，手术范围愈大，硬膜外纤维化愈重，复合因素引起的症状重于单一因素。     

Meningioma of the scapula

Meningiomas account for approximately 15% of all intracranial tumors and are the most common non-glial primary tumors of the central nervous system. Most meningiomas are benign neoplasms with characteristic imaging features. Primary extradural meningiomas account for only 1–2% of all meningiomas. They must be differentiated from intradural meningiomas with secondary extradural extension and/or metastases. The vast majority of extradural meningiomas are found in the skull or in the head and neck region. We report on an extremely rare case of primary extradural meningioma that was located in the scapula. The lesion was resected. Radiographic findings and pathologic features are discussed. To the best of our knowledge, this form of presentation of an extradural meningioma has not been previously described.     

Spinal dural arteriovenous fistula in a case with lipomyelodysplasia

Coexistence of a spinal dural arteriovenous fistula within a dysraphic spinal lesion is a very rare situation. We report a 40-year-old man who presented with low back pain and progressive paraparesis. MR images showed an intradural high signal intensity mass at the L2-L3 level containing irregular signal void structures. Spinal angiography revealed extradural arteriovenous fistula with three connections, drained by a tortuous perimedullary vein.     

Bildgebung intraduraler Raumforderungen

Spinal tumors are often categorized into extradural, intradural extramedullary, or intramedullary. Although this classification represents somewhat of an overgeneralization as a lesion may reside in two compartments, it still helps to characterize spinal tumors. In the intradural, extramedullary space, primary tumors, such as neurofibroma and meningioma, are relatively common. Secondary tumors or leptomeningeal enhancement also occur.In the intramedullary space, primary tumors are far more common than secondary tumors or metastases.     

Assessment of extradural degenerative disease with Gd-DTPA-enhanced MR imaging: correlation with surgical and pathologic findings

To test whether gadolinium-DTPA-enhanced MR would increase the conspicuity of extradural degenerative disease in the previously unoperated patient, we prospectively studied a group of 30 patients with symptoms suggestive of disk disease. Surgical findings and pathologic correlations were used as an objective measure of accuracy. Gadolinium-DTPA increased the confidence of diagnosis at one of eight operated cervical levels (six patients) and changed the diagnosis from extradural degenerative disease to tumor in one patient. The mechanism of enhancement of the epidural space and peridiskal region appears to be related to accumulation of contrast material within the epidural venous plexus, as well as to epidural fibrosis associated with disk disruption and herniation. While the immediate clinical utility of gadolinium-DTPA for morphologic analysis seems limited to difficult cervical spine cases, the presence of enhancement as a marker of epidural fibrosis and attempted healing may prove to be of great importance in studying the natural history and basic pathophysiology of degenerative disk disease.     

Assessment of extradural degenerative disease with Gd-DTPA-enhanced MR imaging: correlation with surgical and pathologic findings

To test whether gadolinium-DTPA-enhanced MR would increase the conspicuity of extradural degenerative disease in the previously unoperated patient, we prospectively studied a group of 30 patients with symptoms suggestive of disk disease. Surgical findings and pathologic correlations were used as an objective measure of accuracy. Gadolinium-DTPA increased the confidence of diagnosis at one of eight operated cervical levels (six patients) and changed the diagnosis from extradural degenerative disease to tumor in one patient. The mechanism of enhancement of the epidural space and peridiskal region appears to be related to accumulation of contrast material within the epidural venous plexus, as well as to epidural fibrosis associated with disk disruption and herniation. While the immediate clinical utility of gadolinium-DTPA for morphologic analysis seems limited to difficult cervical spine cases, the presence of enhancement as a marker of epidural fibrosis and attempted healing may prove to be of great importance in studying the natural history and basic pathophysiology of degenerative disk disease.     

Chymopapain chemonucleolysis: correlation of diagnostic radiographic factors and clinical outcome

The therapeutic response to treatment of lumbar disk herniation with chymopapain chemonucleolysis is significantly influenced by the criteria used for patient selection. Although careful clinical selection of patients reduces the frequency of treatment failure, some patients do not achieve satisfactory relief of pain with chemonucleolysis. In an attempt to identify objective pretreatment radiographic findings that might refine selection criteria and further reduce the failure rate of chemonucleolysis, a retrospective correlation of pretreatment radiographs and clinical responses was made of 200 consecutive chemonucleolysis patients. Marked improvement in sciatica occurred in 79.9% and 79.3% of patients at early and late follow-up, respectively. There was a significantly higher response rate, however, in patients who had definite radiographic evidence of focal disk herniation and in those patients with definite radiographic evidence of nerve-root compression (marked nerve-root deviation, nerve-root flattening or edema, root-sleeve amputation) by disk material. Those patients with a preinjection disk height greater than the mean had a slightly better response rate (91.1%) than those whose disk height was smaller than the mean (80.0%). Most cases of treatment failure could be attributed to an incorrect radiographic diagnosis, treatment of patients with equivocal diagnostic studies, the presence of "free" disk fragments, and causes of nerve-root compression unresponsive to chymopapain.     

Pädiatrische intraspinale Neoplasien

With an overall incidence of 10?% of all central nervous system tumors, spinal tumors are relatively rare in children. The majority of these tumors are astrocytomas and ependymomas (70?%) followed by rare non-glial tumor entities, such as gangliogliomas. They can be differentiated into intramedullary, extramedullary intradural and extramedullary extradural tumors according to their occurrence within the anatomical intraspinal compartments. The clinical presentation is generally unspecific. Longer lasting back pain or a gradually worsening scoliosis are often the first signs of the disease. Neurological deficits, such as gait disturbances and paresis often occur after a time delay. In rare cases increased intracranial pressure has been reported. Knowledge concerning potential organ manifestations, resulting complications and typical radiological presentation, especially in magnetic resonance imaging are mandatory for adequate diagnosis and treatment of affected patients.     

Imaging of tumors of the spine and spinal cord

Imaging of the spine and spinal cord has traditionally been accomplished with plain radiography, myelography, and CT. Recently, MR imaging has become the technique of choice in the assessment of lesions of the spine and spinal cord. MR imaging provides accurate localization of intramedullary, intradural extramedullary, and extradural tumors. Ependymomas and low-grade astrocytomas are the most common intramedullary tumors. MR imaging findings are distinguishable by the delineation and size of the lesion, and the signal intensity on T2-weighted images. Other less common tumors include malignant astrocytomas, hemangioblastomas, and intramedullary metastasis. Numerous foci of high-velocity signal loss are seen in the hemangioblastomas. Metastasis, meningiomas, and schwannomas are the most common intradural extramedullary tumors. Meningiomas are characterized by dural enhancement on postcontrast T1-weighted images. Schwannomas and neurofibromas often erode bony structures and appear to be dumbbell-shaped. Epidural metastasis accounts for the majority of extradural tumors. Primary malignant extradural tumors include lymphomas, chordomas, and so on. The most common primary benign extradural tumor is hemangioma, which often appears to be hyperintense on both T1-weighted and T2-weighted images. Intramedullary non-neoplastic lesions include demyelinating, vascular, and infectious diseases. Diffuse, peripheral, or speckled contrast enhancement, and lack of contrast enhancement may suggest non-neoplastic lesions.     

Gd-DTPA-enhanced 3D MR imaging of cervical degenerative disk disease: initial experience.

PURPOSE: To assess whether a single enhanced T1-weighted gradient echo volume sequence, with the appropriate reformatted images, could be equivalent to a more conventional 2D set of MR sequences for the evaluation of cervical extradural degenerative disk disease (bony canal and foraminal stenosis; disk herniation). MATERIALS AND METHODS: Sixty-one patients evaluated for extradural degenerative disease by MR were imaged with a "standard" MR examination (Sagittal T1-weighted spin echo, axial low flip angle gradient echo), were then given 0.1 mmol/kg Gd-DTPA intravenously, and reimaged with either a 3D FLASH (fast low angle shot), TR 40/TE 7/1 excitation), 40 degree flip angle, acquired as 64, 2-mm sagittal partitions, or a 3D turbo FLASH (MP RAGE-magnetization prepared rapid acquisition gradient echo) (10/4/1), 10 degree flip angle acquired as 128, 2-mm coronal partitions. The volume sequences were reconstructed in the axial plane, and right and left 45 degree oblique coronal planes. The two sets of examinations (standard vs volume) were prospectively interpreted by two neuroradiologists for quality of examination, and location, type, and severity of extradural degenerative disease in a random, blinded, independent fashion. RESULTS: There was no significant difference between the standard examination and the 3D MP RAGE for central extradural disease. The 3D FLASH examination was significantly worse than the standard examination in identification of central extradural disease, with an average of 21 herniations not identified, or underestimated in size. Neither the 3D FLASH, nor the 3D MP RAGE examinations showed any significant improvement compared to the routine 2D examination for the location and severity of foraminal disease. CONCLUSION: If extradural degenerative disk disease is being evaluated, then a single enhanced 3D T1-weighted imaging sequence taking 6 minutes can be equivalent to a routine set of mixed 2D spin echo and low flip angle gradient echo sequences.     

Posttraumatic lumbar intraspinal extradural-intradural ossification

Summary A case of intraspinal calcification having mainly the configuration of an intradural cast is presented. The traumatic etiology is obvious, and we consider, that the dural sac and nerve root lacerations were associated with intradural as well as extradural hematomas, which later became calcified.     

游离型腰椎间盘突出的MRI表现

目的:研究游离型腰椎间盘突出在MRI中的表现及诊断价值。资料与方法:回顾性分析24例经手术病理证实的游离型腰椎间盘突出患者的MRI表现。结果:24例游离髓核中，23例位于椎管内硬膜外，其中15例见于椎弓根内侧缘，5例位于椎间孔处，3例位于黄韧带区；仅1例位于髓外硬膜下。24例均为单发病灶，呈卵圆形、圆形或不规则形；游离髓核于T1WI上呈等或低信号，T2WI上呈等或高信号，当有钙化时，呈低信号灶。其中10例作了增强扫描，病灶中心部分均无强化表现，有4例呈边缘强化。结论:MRI对游离髓核能作出正确的诊断，是首选的检查方法。     

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.     

A sign of lumbar disk herniation recognizable on lateral CT generated digital radiograms

Computed tomography is a very sensitive and fairly specific imaging mode for diagnosing herniated disks in patients with low back pain and radiculopathy. We describe a new CT sign associated with posterior disk herniation that consists of a bony defect on the lower posterior angle of the proximal vertebral body and endplate shown on CT generated digital radiograms. This finding, by no means constant, is encountered frequently enough to be described as a sign of posterior disk protrusion. It often occurs concomitantly with posterior avulsion of a bone fragment probably related to avascular bone necrosis of the posterior inferior angle of the endplate.     

Magnetic resonance imaging in the management of suspected spinal canal disease in patients with known malignancy

AIM: The aim of this study was to examine the spectrum of spinal canal disease in patients with known malignancy using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred and fifty-five patients underwent a total of 159 spinal MRI examinations over a three-year period. Patients were examined using a 1.0T magnet and a phased array surface spine coil. Sagittal T1 weighted spin echo and STIR sequences were routinely employed. Axial T1 and T2 weighted spin echo images were obtained at sites of identified pathology. Contrast enhanced sagittal and axial T1 weighted spin echo images were acquired when the unenhanced appearances did not correlate with the clinical findings or when the images suggested intradural or intramedullary disease. RESULTS: Malignant disease affecting the spinal cord or cauda equina was noted in 104/159 (65%) patients (extradural n= 78, intradural n= 20, intramedullary n= 7); one patient had evidence of both intradural and intramedullary deposits. Multiple levels of extradural cord/cauda equina compression were present in 18/78 patients (23%). The thoracic spine was the most frequently affected (74%). Bone elements were the major component of extradural compression in 11/78 patients (14%). Intradural metastases were multiple in 15/20 patients (75%). Four of the six solitary intramedullary metastases were situated in the conus medullaris. CONCLUSION: Magnetic resonance imaging of the entire spine is the investigation of choice in patients with known malignancy and suspected spinal canal disease. Contrast-enhanced images should be acquired when the unenhanced appearances do not correlate with the clinical findings or when they suggest intradural or intramedullary disease.Loughrey, G. J. (2000). Clinical Radiology55, 849-855.     

腰椎间盘手术后症状复发CT表现

目的：对腰椎间盘突出术后症状复发病人的ＣＴ表现进行了分析,以了解复发情况。方法：３７ 例腰椎间盘突出手术病人,术后均有不同程度反复发作的腰腿痛。其中４例呈痉挛性疼痛。２７ 例作全椎板切除,１０例作半椎板切除。４例平扫加增强扫描。１０例ＣＴＭ 扫描。结果：术后椎管表现正常６例（１６．１％ ）,椎间盘突出复发者１６例（４３．２％ ）,硬膜外纤维疤痕形成２１例（５６．９％ ）,侧椎管狭窄１８例（４８％ ）,化脓性椎间盘炎４例（１．１％ ）。结论：腰椎间盘突出术后症状复发病人ＣＴ扫描,可以解释症状发生的原因。