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.     

结核性脊髓脊膜炎的MRI诊断价值

目的：探讨MRI对结核性脊髓脊膜炎的诊断价值。方法：对21例结核性脊髓脊膜炎增强前后的MRI进行回顾性分析。结果：所有21例MRI平扫均可见脊膜受累,主要表现为脊膜不规则增厚,蛛网膜下腔狭窄或闭塞、分隔样改变、囊肿形成,神经根增厚;增强扫描表现为增厚的脊膜呈线状、斑块状、结节状和环状强化。本组21例中脊髓肿胀17例,脊髓空洞6例,髓内结核瘤5例。结论：MRI平扫和增强扫描可清晰显示结核性脊髓脊膜炎的病变部位和累及范围,可为临床治疗及判断预后提供影像学参考。     

Gd-DTPA-enhanced MR of suspected spinal multiple sclerosis

A prospective study was undertaken to evaluate the potential of Gd-DTPA-enhanced MR to differentiate active from inactive demyelinating lesions of the cervical spinal cord. Five patients with elongated high-signal-intensity lesions in the cervical cord on long TR/TE spin-echo MR images and a clinical suspicion of demyelinating disease had MR before and after IV Gd-DTPA. Delayed contrast enhancement (after 45-60 min) of the lesions was seen on short TR/TE images in two patients with clinically active disease, but no enhancement could be detected in three patients with stable disease. The patients with active disease underwent repeated MR examinations until the enhancement disappeared. The decrease in Gd-DTPA enhancement paralleled a decrease in clinical signs and symptoms of cervical myelopathy. MR is useful in evaluating patients suspected of having demyelinating disease. The MR finding of asymptomatic lesions in the brain lends support to the diagnosis of multiple sclerosis. Other possible causes of myelopathy, such as spinal cord compression and intramedullary tumor, can be excluded with the use of MR.     

Spinal intradural capillary hemangioma: MR findings

We report a case of a spinal intradural capillary hemangioma. On MR images, a well-circumscribed intradural mass was detected at the T8-T9 level. The signal intensity of the mass relative to the spinal cord was isointense on T1-weighted images, hyperintense on T2-weighted images, and showed homogeneous, strong enhancement on contrast-enhanced T1-weighted images. The mass had both extramedullary and intramedullary components.     

Intramedullary spinal cord metastases, mainly of nonneurogenic origin

The clinical data and imaging studies of 12 patients with intramedullary metastases were reviewed retrospectively to see if these lesions had a typical radiographic appearance and to determine the sensitivity of the various radiologic examinations. The lesions were identified antemortem by either myelography, CT, MR, and/or intraoperative spinal sonography (IOSS). Final diagnosis was based on biopsy material from either the spinal cord lesion, another metastatic site, and/or the primary tumor. Ten patients had primary tumors located outside the central nervous system, while only two patients had primary brain tumors. Metrizamide myelography and CT demonstrated a definite intramedullary mass in nine of 11 patients. In five patients the mass was relatively small, well-defined, single, and resembled a primary spinal cord neoplasm. In the other four patients, longer and sometimes several segments of the cord were involved. These appeared irregular and nodular and were often associated with intradural lesions at separate sites. MR detected not only enlargement and abnormal signal in the cord but also clinically unsuspected brain lesions. IOSS localized lesions for biopsy and monitored tumor resection. These various imaging procedures showed that cord metastases were often more extensive than anticipated clinically. Spread of tumor into the spinal and intracranial subarachnoid space was common. Imaging of the entire spinal canal and brain, preferably with MR, is therefore recommended to aid in diagnosis, prognosis, and treatment.     

Contrast-enhanced T1-weighted three-dimensional gradient-echo MR imaging of the whole spine for intradural tumor dissemination.

BACKGROUND AND PURPOSEWhen evaluating intradural tumor dissemination in the spine, contrast-enhanced T1-weighted 2D spin-echo (2D-SE) images are frequently problematic because most of the lesions are very small. Our purpose was to compare 2D-SE images with 3D gradient-echo (3D-GE) postcontrast images to determine which technique is better for depicting intradural tumor dissemination.METHODSTen patients with and 10 without intradural tumor dissemination were examined prospectively with MR imaging. After contrast administration, all patients underwent sagittal imaging with 2D-SE and 3D-GE sequences. Subsequently, the 2D-SE, 3D-GE, and multiplanar reconstruction (MPR) images of the 3D-GE sequence were evaluated for image quality, lesion detectability, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the disseminated lesions.RESULTSAlthough delineation of spinal cord from CSF was slightly poorer on the 3D-GE sequences than on the 2D-SE sequences, the difference was not significant. In the evaluation of image artifacts and contrast between spinal cord and CSF, there was no significant difference. In seven patients with nodular enhancement, the 3D-GE sequence detected 46 lesions and the 2D-SE sequence detected 36. With MPR, the greatest number of lesions (n = 51) was detected, and vascular enhancement was clearly distinguished. There was no difference in SNR and CNR of lesions between the 3D-GE and 2D-SE sequences.CONCLUSIONThe contrast-enhanced 3D-GE technique offers advantages over 2D-SE imaging in detecting intradural tumor dissemination, especially when the MPR technique is applied. This technique should be used for detecting intradural tumor dissemination.     

Spinal cord infection: myelitis and abscess formation.

PURPOSEOur purpose was to describe the MR findings and evolution of spinal cord abscess and to define those MR features that allow differentiation of cord infection from other intramedullary abnormalities.METHODSWe retrospectively reviewed the MR studies of all patients in whom intramedullary spinal cord abscess was proved either by blood or cerebrospinal fluid culture or by serologic examination at our institution between January 1988 and January 1996. The study group included four adults and two children, 7 to 74 years old (mean age, 38 years).RESULTSInitial MR studies showed intramedullary high signal on T2-weighted sequences with poorly defined marginal enhancement on T1-weighted images. On follow-up contrast-enhanced T1-weighted studies, the lesions had well-defined enhancing margins with central low signal intensity. After the initiation of therapy, T2 signal abnormalities decreased markedly and contrast-enhanced studies showed ring enhancement. These T1 findings resolved with treatment over serial studies in four patients. The organisms identified were Streptococcus milleria, S pyogenes, atypical mycobacteria, Mycobacterium tuberculosis, and Schistosoma mansoni (both children).CONCLUSIONA characteristic sequence of imaging findings aids in the differentiation of cord infection from other intramedullary lesions.     

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.     

Tuberculous arachnoiditis of the spine: findings on myelography, CT, and MR imaging

Tuberculosis (TB) is a rare cause of spinal arachnoiditis. It may occur primarily or secondary to intracranial or vertebral infection; unlike other types of arachnoiditis, it frequently involves the spinal cord as well as the meninges and the nerve roots. We retrospectively reviewed 13 conventional myelograms, eight CT myelograms, and five Gd-DTPA-enhanced MR images in 13 patients with spinal TB radiculomyelitis (arachnoiditis). Eleven patients had intracranial TB meningitis at the time of diagnosis or before. Ten patients were less than 30 years old. Conventional myelographic findings included a block of the CSF (11/13), most commonly at the level of the conus medullaris; irregular or indistinct thecal sac contour (9/13); multiple fine and/or coarse nodular defects (8/13); nerve-root thickening (7/13); and vertical bandlike adhesive defects (4/13). CT myelography showed intradural nodular masses suggesting tuberculomas at or just above the level of the block (4/8), irregularity of the spinal cord surface (4/8), irregular filling or obliteration of subarachnoidal space (6/8), and root thickening (5/8). Gd-DTPA-enhanced MR images revealed enhancing nodules suggesting tuberculomas (2/5); enhancement of the dura-arachnoid complex around the cord (3/5); and segmental enhancement of the thoracic cord, suggesting either infarction caused by vasculitis or TB myelitis in association with diffuse cord swelling (1/5). Plain MR findings were much less conspicuous, showing only an indistinct or irregular dura-arachnoid-cord complex (4/5). In conclusion, the conventional myelographic findings are considered to be virtually diagnostic of spinal TB radiculomyelitis in young patients with antecedent or coexisting TB meningitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intramedullary tuberculomas. MR findings in seven patients

Purpose: To describe the MR findings in intramedullary tuberculomas and to discuss the usefulness of MR in the management of this pathology.Material and Methods: A retrospective study of 7 patients from 21 to 60 years of age with clinical and radiological evidence of intramedullary tuberculomas was undertaken. Both T1- and T2-weighted images (WI) were obtained along with postcontrast T1WI. Signal intensities (SIs) of the granulomas were compared with SIs of the normal spinal cord.Results: Six patients showed focus of tuberculosis elsewhere in the body. Six out of 7 showed fusiform swelling of the cord. Ill-defined iso-intensity (in 4 patients) to hyperintensity (in 3 patients) was seen at the site of granuloma on T1WI. On T2WI, 2 patients revealed a hypointense area (with disc enhancement). An iso-hypointense rim was seen surrounding a hyperintense centre in 5 patients (with rim enhancement). Adjacent oedema was seen in all patients. In 2 patients meningeal enhancement was also seen. In 2 patients the histopathology following surgical biopsy confirmed the diagnosis. In the remaining 5 patients, another known focus of tuberculosis elsewhere in the body and a marked response to antitubercular treatment was considered confirmatory for tuberculomas.Conclusion: Hypo- or iso-intensity on T2WI within the spinal cord with surrounding hyperintense oedema is suggestive of intramedullary tuberculomas. Central hyperintensities are also detected at times due to a variable amount of caseous necrosis with liquefaction. On T1WI, fusiform swelling of the cord is seen along with iso- to hyperintense foci, surrounded by hypointense oedema of the cord. Such findings should prompt a contrast-enhanced study, which may show single or conglomerate disc- or ring-enhancing lesions. MR thus plays an important role not only in detection and diagnosis, but also in deciding the treatment options and in the follow-up of those patients.     

颅内生殖细胞瘤转移的MRI表现

目的　探讨颅内生殖细胞瘤转移的MR影像学表现 ,为临床治疗方案的选择提供影像学依据。方法　结合文献资料 ,对10例具有转移灶的颅内生殖细胞瘤患者的临床与MRI资料进行分析。结果　 2 5例颅内生殖细胞瘤中的 10例发生转移 ,转移发生率 40 %,其增强MRI可表现为 :①软脑膜条索状增粗 ;②脑或脊髓表面的结节状信号 ,病变累及部位弥漫性肿胀 ,信号不均 ,脑沟消失 ;③肿瘤前部楔形缺损或三脑室后部“笔尖样”扩大 ;④室管膜下层片状或弥漫性高信号 ;⑤颅外转移征象等。结论　增强MRI能准确检测颅内生殖细胞瘤转移 ,为临床确立合理治疗方案提供有价值信息。     

Improved radiotherapy treatment planning for spinal cord tumors using gadolinium enhanced MR imaging

Primary intramedullary spinal cord tumors are frequently difficult to localize for radiation treatment planning. Conventional imaging techniques, including unenhanced magnetic resonance (MR) scans, cannot clearly distinguish residual tumor from surrounding normal spinal cord. Recently, contrast agents have been developed for MR that have considerable promise for improving tumor volume definition. This report describes the impact of contrast-enhanced MR on the treatment planning process for four patients with primary spinal cord tumors and discusses the significance of this technique for patients with these neoplasms.     

MR imaging of intraspinal tumors—Capability in histological differentiation and compartmentalization of extramedullary tumors

Summary Magnetic resonance (MR) images of 29 consecutive patients with intraspinal neoplasms (9 intramedullary tumors, 20 extramedullary tumors) were reviewed to evaluated the utility of MR imaging in distinguishing the intraspinal compartmental localisation and signal characteristics of each lesion. Compartment and histology of all neoplasms were surgically proven. MR correctly assigned one of three compartments to all lesions, 9 intramedullary, 14 intradural extramedullary (6 schwannomas, 3 neurofibromas, 5 meningiomas), and 6 extradural (3 schwannomas, 1 meningioma, 1 cavernous hemangioma, 1 metastatic renal cell carcinoma). All intramedullary tumors showed swelling of the spinal cord itself. In all five extradural tumors a low intensity band was visualized between the spinal cord and tumor. On the other hand, a low intensity band was demonstrated in no cases with intradural tumors. Visualization of this low intensity band is important in differentiating extradural from intradural-extramedullary lesions. We call this low intensity band, the extradural sign. Signal intensity of intradural tumors varied with histology. In extramedullary tumors, signal intensity of schwannomas was similar to that of the cerebrospinal fluid (CSF) both on T1 weighted (inversion recovery) and T2 weighted spin echo (SE) images. On the other hand, meningiomas tended to be isointense to the spinal cord on both T1 and T2 weighted SE images. We found relatively reliable signal characteristics to discriminate meningioma from schwannoma.     

Neoplasms of the spinal cord and filum terminale: radiologic-pathologic correlation.

Intramedullary spinal cord neoplasms are rare, accounting for about 4%10% of all central nervous system tumors. Despite their rarity, these lesions are important to the radiologist because magnetic resonance (MR) imaging is the preoperative study of choice to narrow the differential diagnosis and guide surgical resection. On contrast materialenhanced MR images, intramedullary spinal tumors almost always manifest as expansion of the spinal cord and show enhancement. Syringohydromyelia and cystic lesions are frequently associated with intramedullary tumors. Nontumoral cysts tend to be located at the poles of the tumors and do not enhance on contrast-enhanced MR images, whereas cysts within the substance of the tumor are considered tumoral cysts and typically demonstrate peripheral enhancement. Spinal cord ependymomas are the most common type in adults, and cord astrocytomas are most common in children. Both entities constitute up to 70% of all intramedullary neoplasms. A central location within the spinal cord, presence of a cleavage plane, and intense homogeneous enhancement are imaging features that favor an ependymoma. Intramedullary astrocytomas are usually eccentrically located within the cord, are ill defined, and have patchy enhancement after intravenous contrast material administration. Even with these characteristics, it may not be possible to differentiate these two entities on the basis of imaging features alone. Cord hemangioblastomas are the third most common type of intramedullary spinal tumor. Gangliogliomas commonly extend over more than eight vertebral segments. Paragangliomas and primitive neuroectodermal tumors have an affinity for the filum terminale and cauda equina. Other spinal cord tumors include metastatic disease, which is characterized by prominent cord edema for the size of the enhancing portion, and primary lymphoma.     

Magnetic resonance imaging of spinal cord syndromes

Thirty-four patients with intramedullary space-occupying lesions or cord compression syndromes were examined with a resistive and two different superconductive magnetic resonance (MR) imaging units. Studies were done primarily by the spin-echo (SE) technique and in the majority of patients different pulse sequences were used. Images with short echo-time (TE) and short recovery-time (TR) were best for demonstration of spinal cord anatomy, for depicting cystic portions in intramedullary tumours and for showing syringomyelia. Solid intramedullary tumours showed normal cord signal intensity. Images with prolonged TE and TR predominantly enhanced CSF signal intensity and, to a more considerable extent, solid intramedullary tumours. Thus, the diameter of the subarachnoid space and the presence of a solid intramedullary tumour, not concomitant with a significant enlargement of the spinal cord, could only be recognized on these prolonged SE images. Major advantages of MR in comparison to CT are that the spinal cord can be imaged in the sagittal plane and that beam hardening artifacts do not occur; in comparison to myelography the cord can be imaged directly by MR. Partial volume is a major limitation of MR, not only in the preferably applied sagittal plane. The choice of slice thickness adequate to the diameter of the lesion and straight positioning of the patient for sagittal single slice midline images are fundamental for reliable MR investigations. Another limitation to MR is that cortical bone gives no signal. The actual diameter of the spinal canal therefore cannot be correctly appreciated and consequently it was difficult or impossible to assess spinal stenosis.     

Intramedullary Disease of the Spine: Diagnosis Using Gadolinium-DTPA-Enhanced MR Imaging

Twenty-six patients with suspected lesions of the spinal cord were studied before and after administration of gadolinium-DTPA to assess whether contrast enhancement was useful in the MR evaluation of intramedullary disease. Nine patients had primary tumors, six had benign syringes, three had multiple sclerosis with cord involvement, three had thrombosed vascular malformations, three had probable intramedullary metastasis, and two were normal. Although all lesions were detected on noncontrast MR scans, gadolinium-DTPA was of great help in their delineation and characterization. Specifically, contrast material may be able (1) to localize tumor nidus and separate it from edema, in cases of hemangioblastomas and metastases; (2) to suggest regions of more active tumors, in cases of glioma, for surgical biopsy or removal; (3) to differentiate benign or reactive processes from neoplastic lesions, such as reactive cyst from tumor cyst or hematoma due to thrombosed malformation from tumor hemorrhage; and (4) possibly to differentiate active from inactive lesions, for example, in multiple sclerosis.Because of these advantages, gadolinium-DTPA probably will often be used routinely when intramedullary lesions are detected on noncontrast MR scans.     

MRI in intraspinal tuberculosis

We studied 20 patients with intraspinal tuberculosis (TB), to characterise the MRI features of tuberculous meningitis and myelitis. MRI leptomeningitis and intramedullary involvement in 11 patients, intramedullary lesions alone in 5, leptomeningitis alone in 2, and isolated extradural disease in 2. TB leptomeningitis was characterised by loculation of the cerebrospinal fluid (CSF), nerve root thickening and clumping (seen only in the lumbar region) or complete obliteration of the subarachnoid space on unenhanced images. Gd-DTPA-enhanced images proved useful in 6 cases, revealing linear enhancement of the surface of the spinal cord and nerve roots or plaque-like enhancement of the dura-arachnoid mater complex. Intramedullary lesions included tuberculomas (8), cord oedema (5) and cavitation (3). In seven cases of intramedullary tuberculoma multiple lesions with skip areas were seen, without significant cord swelling. One patient had an isolated lesion in the conus medullaris. The lesions were iso- or hypointense on T1-weighted images, iso-, hypo- or hyperintense on T2-weighted images and showed rim or nodular enhancement with contrast medium.     

Value of intravenous contrast enhancement in the CT evaluation of intraspinal tumors

The usefulness of intravenous contrast-enhanced CT in delineating intraspinal cord tumors has not been well documented. To determine if intradural spinal tumors enhance, if the location and type of tumor can be determined, and if a double dose of contrast material provides more information than a single dose, a retrospective study of 23 patients with proven intradural extramedullary or intramedullary tumors was performed. All the tumors studied with CT after intravenous contrast enhancement showed that most lesions (18/23) enhanced, contrary to published reports. Contrast-enhanced studies delineated the extent of the tumor, helping to separate solid and cystic components. The enhancement pattern of ependymomas and astrocytomas was similar, while schwannomas had a characteristic appearance. A double dose of intravenous contrast material had no apparent advantage over a single dose.     

MR imaging of the cauda equina in hereditary motor sensory neuropathies: correlations with sural nerve biopsy

BACKGROUND AND PURPOSE: Although spinal root abnormalities are known to occur, spinal MR examination is seldom performed in hereditary motor and sensory neuropathies (HMSN). The following work was undertaken to assess the MR imaging spectrum of lumbosacral spinal nerve root abnormalities and determine whether intradural nerve root involvement could be related to any biopsy feature. METHODS: Ten consecutive patients (eight male, two female; age range, 28-65 yrs) with Charcot-Marie-Tooth (CMT) (type I = 5, type II = 2) and Déjèrine-Sottas disease (DSD) (n = 3) underwent a contrast-enhanced lumbosacral MR examination. Sural nerve biopsy was performed in all patients. Atypical clinical features were present in two patients. The MR scans of each patient were reviewed for possible causes of myeloradiculopathy, spinal nerve root and ganglia dimensions, signal change, and abnormal enhancement. RESULTS: In the seven patients with CMT, abnormal MR findings were intradural nerve root hypertrophy (n = 2), signal abnormalities (n = 2), and enhancement (n = 3). Two of three patients with DSD had the abnormal MR finding of intradural nerve root enhancement. In both patients with atypical clinical features, MR imaging showed nerve root hypertrophy and enhancement. Both findings were related to an increased number of onion bulbs at sural nerve biopsy. Inflammatory infiltrates were not observed in any patients. CONCLUSION: In patients with HMSN enhancement of intradural spinal nerve roots, whether or not associated with marked thickening, may be found on lumbosacral MR examinations. Spinal nerve root thickening may be responsible for atypical symptoms, and its visibility on MR images represents a useful adjunct to diagnosis. Lumbosacral spinal nerve root abnormalities were related to an extremely high number of onion bulbs (indicating active demyelination) at sural nerve biopsy. Nerve root enhancement does not seem to be related to inflammatory infiltrates.     

髓内肿瘤的磁共振诊断与鉴别诊断

本文通过对30例髓内肿瘤和20例非肿瘤病变MR表现的回顾性对比分析,总结了髓内肿瘤MR诊断和鉴别诊断经验。指出髓内肿瘤的MR主要征象为脊髓局部增宽、膨大,病灶Gd-DTPA明显强化,以及伴有囊变。而非肿瘤病变脊髓轮廓改变较轻,Gd-DTPA为轻至中度强化。增强特点为偏心性、点片状或环状,较具特异性。