Morphology and dimensions of the thoracic cord by computer-assisted metrizamide myelography

Computed tomographic (CT) measurements of the thoracic spine and its contents were obtained in 33 patients undergoing metrizamide myelography for various spinal disorders. Twenty-eight of these patients had symptoms referable to the cervical or lumbar region and form the basis of this study. Five patients had symptoms referable to the thoracic spine. Sagittal and coronal CT measurements of the thoracic cord and subarachnoid space were obtained in all cases. In addition, macroscopic measurements of the thoracic cord were obtained from 10 autopsies for correlation with the CT findings. The technical aspects of the measurements are discussed; the normal morphology of the thoracic cord and thecal sac is presented; and the metrizamide CT pattern associated with pathologic lesions involving the thoracic cord is analyzed.     

Neurosarcoidosis of the conus medullaris and cauda equina

An uncommon case of neurosarcoidosis of the conus medullaris and cauda equina is described in a 24-year-old man with a 4-year history of urological symptoms and rash. Chest X-ray and biopsy confirmed sarcoidosis and MRI diagnosed conus medullaris involvement.     

Iopamidol and metrizamide for myelography: prospective double-blind clinical trial

In a comparative randomized double-blind study, 73 patients underwent myelography using iopamidol (36 patients) or metrizamide (37 patients) as contrast medium. The overall diagnostic adequacy of iopamidol myelography was found to be comparable to that of metrizamide myelography. The incidence of examinations graded as superior (64%) or adequate (36%) with iopamidol was equivalent to that with metrizamide (57% superior, 43% adequate). Adverse reactions after iopamidol myelography were fewer, less severe, and generally of shorter duration than those associated with metrizamide. In the iopamidol group, adverse reactions occurred in nine (25%) patients, all of whom experienced mild or moderate headache, one with nausea, vomiting, and fatigue. In the metrizamide group, adverse reactions occurred in 17 (46%) patients, all of whom experienced mild or moderate headache, six with nausea and vomiting and four with back and leg pain. Of nine individuals who underwent myelography using 300 mg 1/ml metrizamide injected via lateral C1-C2 puncture, three experienced a toxic encephalopathy with confusion, dysphasia, headache, nausea, and vomiting, and a fourth individual suffered severe nausea, vomiting, fever, and irregular pulse. Encephalopathy was not observed in any of the 11 patients in whom myelography was performed via lateral C1-C2 puncture with a similar concentration of iopamidol. No seizures were encountered, and no clinically significant changes in laboratory studies were observed with either contrast medium.     

脊髓圆锥髓内支气管源性囊肿1例

患者 女,29岁.近7年无明显诱因出现腰痛,双下肢疼痛,以右侧为著,走路自觉无力,大小便不畅.体格检查:左上肢、左下肢、右上肢肌力Ⅴ级,右下肢肌力Ⅳ级,肌张力正常. MRI检查示:T12～L2椎体水平脊髓圆锥髓内可见一囊性扩张性占位性病变,T1 WI呈低信号(图1),T2 WI以高信号为主(图2),其内信号欠均匀,轴位T2WI上可见分层现象(图3),大小约2.1cm×1.7 cm×6.5 cm,边界尚清,相应节段马尾及终丝向前推压移位,增强扫描MRI示椎管内病灶无明显强化(图4).     

Epidermoid cyst of the conus medullaris: atypical MRI and angiographic features

We report a 50-year-old man with an epidermoid cyst of the conus medullaris which showed a nodular gadolinium enhancement on MRI and a blush on angiography. These radiological features are compared with pathological examination.     

Lumbar myelography with iohexol and metrizamide: a comparative multicenter prospective study

Diagnostic quality of radiographs and adverse reactions associated with the use of metrizamide and iohexol as contrast agents in lumbar myelography were compared in a prospective randomized double blind study in 350 patients at seven centers. The contrast media were administered in comparable volumes at a concentration of 180 mg I per ml. Overall quality of radiographic visualization was graded good or excellent in 95% of 175 metrizamide studies and in 98% of 175 iohexol studies. Ninety-three patients examined using metrizamide (53%) and 130 patients examined using iohexol (74%) experienced no discomfort during or after myelography. Postmyelographic headache was associated with 38% of metrizamide examinations and 21% of iohexol examinations. Nausea and vomiting were also more common with metrizamide. Five patients examined using metrizamide (3%) experienced transient confusion and disorientation following lumbar myelography. No such reactions were observed following iohexol myelography.     

Cervical disk syndromes: value of metrizamide myelography and diskography

This paper reports on the respective diagnostic values of myelography with water-soluble contrast media and diskography in a study of 100 patients examined between 1979 and 1981 and operated on because of cervical disk disease. The results of the study led to a change of the diagnostic procedures formerly applied in radicular syndromes (i.e., diskography, and then perhaps myelography) and in cervical myelopathy (myelography, rarely followed by diskography). Now cervical metrizamide myelography is always performed first. Diskography is only indicated in radicular syndromes to determine the segment causing clinical symptoms when there is a polysegmental space-occupying lesion on the myelogram in combination with a mono- or oligoradicular neurologic symptomatology; or in the case of a normal myelogram with complaints resistant to conservative treatment.     

Cognitive and affective changes after myelography: a comparison of metrizamide and iohexol

A battery of brief cognitive tests and a mood scale were administered to 42 patients before and after cervical myelography with either metrizamide (20 patients) or iohexol (22 patients). The patients receiving metrizamide experienced a deterioration in mood after myelography and a relatively greater decline in cognitive test performance than did those receiving iohexol. These two side effects tended to occur together in the metrizamide group, suggesting a common underlying cause; but there was no correlation between changes in mood and cognitive function after myelography with iohexol. These results suggest that metrizamide has a greater neurotoxic effect than iohexol.     

Glioblastoma multiforme of the conus medullaris in a child: description of a case and literature review

We describe a case of glioblastoma multiforme of the conus medullaris in a child. MR imaging showed at the T12-L1 level an intramedullary mass with signal alteration, with only two nodules of contrast enhancement. The finding was consistent with astrocytoma. Pathologic evaluation was consistent with glioblastoma multiforme. Nine months after the surgical treatment, the patient showed leptomeningeal recurrence. This case appears to be unusual for both the hysto-type and the nonspecific MR imaging features.     

Gas and metrizamide myelography in abnormalities of the craniovertebral junction

Ten symptomatic patients with skeletal abnormalities of varying etiology at the craniovertebral junction were studied with gas or metrizamide myelography. The type of compressive pathology was accurately delineated by these techniques. The surgical approach was determined by the findings on the myelograms.     

Risk of seizures after myelography: comparison of iohexol and metrizamide

A parallel, double-blind, randomized study comparing iohexol and metrizamide--both 180 mg l/ml--in lumbar myelography was carried out in 60 consecutive patients. Eight to 15 ml of contrast medium were administered with the upper level at the middle thoracic column. A detailed neurologic examination was performed before and 24 hr after myelography. EEG recordings--evaluated visually and with fast Fourier transformation analysis--and somatosensory evoked responses were registered before, 6 hr after, and 24 hr after myelography. All patients were observed for adverse reactions for 24-48 hr. Iohexol did not produce any epileptiform activity but epileptiform activity was detected in five patients receiving metrizamide. Iohexol produced significantly less frequent and less severe EEG changes than did metrizamide both at visual evaluation (p less than .0025) and at fast Fourier transformation analysis (p less than .04). No significant changes occurred in the early components of the somatosensory evoked potentials after either contrast medium. Iohexol caused significantly (p less than .002) less frequent and less severe adverse reactions than did metrizamide. The neurologic examination revealed no changes of clinical importance with either contrast agent.     

Ventriculus terminalis of the conus medullaris: MR findings in children.

PURPOSETo determine the appearance of the ventriculus terminalis of the conus medullaris and the frequency with which it is seen on MR.METHODSFour hundred eighteen normal spine MR examinations were reviewed.RESULTSEleven (2.6%) of 418 children, all younger than 5 years of age, demonstrated an ovoid, nonenhancing, smooth dilation of the central canal within the conus medullaris. Averaged volume of the oblate spheroid was 0.18 cm3. Fluid within the cavity behaved as cerebrospinal fluid on all pulse sequences, and there was no abnormal signal in the cord tissue surrounding the cavity.CONCLUSIONAsymptomatic localized dilatation of the ventriculus terminalis is a normal developmental phenomenon that can be seen on MR.     

Outpatient metrizamide myelography: prospective evaluation of safety and cost effectiveness

A group of 228 consecutive patients undergoing metrizamide myelography was prospectively evaluated for postprocedure symptoms. The observed prevalence of these symptoms concurs with previously reported inpatient studies, with the most common sequelae being exacerbation or onset of spine or extremity pain, headache, nausea, and paresthesia. Limitation of administered dose of metrizamide in lumbar myelography may slightly reduce the occurrence of common symptoms, but withdrawal of contrast medium at the completion of examination had no impact on their occurrence. There was a higher occurrence of paresthesia in cervical myelography, but otherwise there was no significant difference in symptoms between cervical and lumbar studies. Outpatient metrizamide myelography can be performed with relative safety with the potential for significant cost savings.     

圆锥位置正常型脊髓栓系综合征MRI表现与临床对比

目的 探讨圆锥位置正常型脊髓栓系综合征(TCS)临床及MRI特征性表现.方法 回顾性分析经手术及病理证实的圆锥位置正常型脊髓栓系综合征患儿13例,将其临床表现、术前MRI征象及术中所见情况进行对比.另对12例怀疑有此种圆锥位置正常型TCS患儿在常规MRI检查基础上加做俯卧位扫描加以筛查.患儿全部行MRI检查、尿动力学及双下肢肌电图检查、MSCT检查,手术方式采用终丝离断加椎板成形术治疗.结果 术前MRI及MSCT显示患儿脊髓圆锥末端均位于L2椎体下缘以上,部分伴有骶椎板未融合及脊柱侧弯等其他病变.轴位及矢状位可观察到19例患儿终丝及马尾神经有靠近或紧贴于后硬膜囊的趋势,椎管内马尾神经排列不规则,两侧粗细不等等征象.12例疑似患儿经俯卧位MRI检查排除8例.尿流动力学及双下肢肌电图结果显示部分患儿存在损害.术中可见终丝呈弓弦样紧张,紧贴于硬脊膜后缘,17例终丝直径在1.5 mm以上,4例终丝发黄;3例马尾神经有不同程度的粘连呈束状.显微镜下分离终丝并切断,术中即可见脊髓圆锥末端回缩3例.术后病理示3例终丝脂肪组织异常增生,4例终丝纤维组织及脂肪组织异常增生,10例纤维组织异常增生.结论 圆锥位置正常型TCS可被认为是一种特殊TCS亚型,通过观察患儿终丝及马尾神经MRI影像学特征,并加做俯卧位MRI检查进行对比,可对此种类型TCS进行初步诊断.     

Myxopapillary ependymoma of the conus medullaris with subarachnoid haemorrhage: MRI in two cases

Subarachnoid haemorrhage due to cauda equina tumour is rare. We report two myxopapillary ependymomas of the conus terminalis, presenting with in this way. Rims of low signal were observed at their upper and lower borders, mainly on T2-weighted images. This finding has been described in ependymomas of the cervical region but not, to our knowledge, in myxopapillary ependymomas of the conus terminalis. Received: 8 August 2000 Accepted: 8 September 2000