脑发育性静脉异常的影像学诊断

目的:分析脑发育性静脉异常的CT、MRI和DSA表现,提高对本病的认识。方法:17例脑发育性静脉异常(DVA)患者中15例行MRI检查、CT检查6例、DSA检查4例。对DVA在不同影像检查的表现进行分析,对DVA的部位、分型、引流方式以及合并的其它异常进行探讨。结果:17例患者有21个DVA,其中3例多发,4例患者合并有海绵状血管瘤。21个DVA中幕上7个,幕下14个,根据其位置分为浅型(皮层和皮层下区)12个和深型9个,其引流静脉中单支引流14例,多支引流3例。增强CT、增强MRI和DSA静脉期均能清晰显示其特征性表现既"水母头"状扩张的髓静脉汇入粗大的引流静脉干。结论:增强CT、MRI以及DSA检查均能正确诊断和评价DVA,DSA是诊断DVA并与其它血管畸形鉴别的金标准;多种序列组合使MRI能更全面的评价DVA及其合并的其它脑实质异常,是DVA检查的首选方法。     

Multiple occult vascular malformations of the brain and spinal cord: MRI diagnosis

Summary We report a patient with multiple angiographically occult vascular malformations in the brain and spine. Magnetic resonance imaging showed multiple lesions in brain and spine with hypointense areas on both T1 and T2-weighted images. These hypointense areas are usually secondary to hemosiderin deposits consistent with remote bleeding in the lesions. We conclude that when magnetic resonance reveals an intraspinal lesion with signal intensity characteristics consistent with a vascular malformation, an examination of the brain should be performed to rule out associated intracranial lesions. The finding of multiple lesions in the brain with identical signal intensity characteristics reinforces the diagnosis of vascular malformation.     

Cerebral venous angiomas

Summary Sixteen cases of cerebral venous angiomas, seven cerebellar and nine supratentorial were imaged by magnetic resonance, using a T1 sequence and a motion compensated T2 sequence. The transcerebral draining vein of the lesion could be identified in thirteen out of sixteen patients. On T1-weighted images all the lesions were hypointense. On T2-weighted images, five lesions were hypointense, and eleven were hyperintense consistent with slow flow. In three cases the lesion was hemorrhagic. Three lesions with hypointense aspect on T1 and hyperintense aspect on T2-weighted images were only seen in retrospect, due to partial volume averaging in two and concomitant chronic hemorrhage in one. Before contrast, the peripheral dilated medullary veins could only be identified in five cases. On T2-weighted images, in three of these lesions the signal was higher than in the draining veins, pointing to a slower flow. After intravenous administration of Gadolinium, performed in twelve patients, the main transcerebral draining vein as well as the peripheral medullary veins could be well identified in all patients.     

An unusual cause of hydrocephalus: aqueductal developmental venous anomaly

Vascular malformations are infrequent causes of aqueductal stenoses, developmental venous anomaly (DVA) being the rarest among them. DVAs, also known as venous angiomas, are congenital in origin and characterized by dilatation of vessels in the superficial and deep venous system. Although they are usually clinically silent, they can be complicated by hemorrhage, seizures and neurologic deficits. Herein, we report MR imaging findings of a 7-year-old girl whose hydrocephalus was due to an abnormal vein coursing through the aqueduct.     

Magnetic resonance angiography of cerebral developmental venous anomalies: its role in differential diagnosis

Summary CT, MRI and contrast angiography of 20 patients with 21 developmental venous anomalies (DVAs), so-called venous angiomas, were compared with magnetic resonance angiography employing a two-dimensional time-of-flight technique (2D-MRA). MRA was diagnostic in 17 DVAs, when both the primary 2D slices and the maximum-intensity-projection images were read. Contrast angiography still provides the best visualization of both DVA components: dilated medullary veins and transcerebral draining vein; however, it is an invasive procedure and delivers no information about brain parenchyma. We regard MRI as necessary in cases with a suspected DVA because of the high rate of association with cavernomas: 33% in this study. Acute neurological symptoms were caused by haemorrhage from an associated cavernoma and not from the DVA in 4 such cases. Thus MRA combined with MRI obviates angiography in most cases and offers a noninvasive diagnostic strategy adequate for DVAs.     

Gadodiamide injection at two dose levels in MRI of CNS lesions: a phase-III study

A double-blind, randomized, parallel study was conducted to evaluate the safety and diagnostic utility of gadodiamide injection (a nonionic chelate of gadolinium and diethylenetriamine pentaacetic acid bis-(methylamide) [Gd-DTPA-BMA]) when administered IV for MRI of the central nervous system (CNS) at doses of 0.1 mmol/kg body weight (b. w.) or 0.3 mmol/kg b. w. A total of 24 patients received the lower dose and 23 the higher dose. Gadodiamide injection was administered to patients referred for MRI due to known or suspected CNS lesions. No clinically significant difference in blood parameters or efficacy was found between the two groups. The number of patients with adverse events other than discomfort was higher in the 0.3 group compared with the 0.1 group. In the 0.1 group, none of the 24 patients experienced any adverse events other than discomfort, and in the 0.3 group, 5 of 23 patients (21.7%) experienced a total of five adverse events other than discomfort. All adverse events were of mild or moderate intensity. Postinjection MR scans provided new information that affected patient management in the case of 6 patients in the 0.1 group and 9 in the 0.3 group. Correspondence to: O. Salonen     

Parenchymal lymphoma of the brain on initial MR imaging: A comparative study between primary and secondary brain lymphoma

Background and purpose

Parenchymal lymphomatous brain masses have not been investigated considering if they are primary or as a part of systemic lymphoma (secondary) on imaging studies previously. We aimed to determine characteristics of the secondary parenchymal lymphomatous involvement of the brain and to find if there is any radiologic feature to help discrimination of untreated primary and secondary central nervous system lymphoma on patients’ initial magnetic resonance imaging.

Materials and methods

We evaluated MR images of 18 patients with the diagnosis of primary (n = 12) and secondary central nervous system lymphoma (n = 6). We considered the number, localization, enhancement pattern, signal characteristics, diffusion properties, presence of hemorrhage and presence of butterfly pattern on MR imaging at initial presentation.

Results

Secondary central nervous system lymphomas predominantly presented as multiple (n = 4, 66.7%) lesions. Homogenous nodular enhancement and supratentorial white matter involvement were present in all patients with butterfly pattern and infiltrative/perivenular enhancement in half (n = 3) of the patients. Deep gray matter (n = 1, 16.7%) and infratentorial involvement (n = 1, 16.7%) were scarce and no ring enhancement was observed. There was no statistically significant difference in any of the investigated MR features between the two groups.

Conclusion

Statistical analyses revealed no significant distinctive radiologic characteristics between primary and secondary lymphoma of the brain parenchyma.     

The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

Background and purpose

To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations.

Methods

Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with “sure start” technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with χ²-test. We compared the results with DSA and operation results.

Results

The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show AVM not AVF. The type differentiations of all the other 16 patients were consistent with DSA results. For 13 cases with positive CT spinal angiography results, DSA displayed 20 feeding vessels, among which 16 vessels were displayed correctly by CT spinal angiography, four could not be visualized, and two turned out to be false-positive. Fistulas were not displayed in six cases by CT spinal angiography. Draining veins were displayed clearly in all cases, which agreed with DSA results. Four cases who took CE-MRA obtained the same type diagnosis as that from CT spinal angiography. Feeding arteries were not displayed in CE-MRA of one case, but could be clearly visualized in other three cases, and the results agreed with CTA and DSA results. Fistulas could be seen in two cases. Draining veins and the disease range could be displayed distinctly by 3D CE-MRA.

Conclusion

CT spinal angiography is quite valuable for diagnosing vascular malformation of spinal cord. It can be a screening exam before DSA, and has a guiding effect on DSA, reducing the amount of time required for DSA.     

Double cerebral venous angiomas: MRI

Using a 1.5 Tesla MR imager, we examined 58 patients with venous angiomas (VA); images were also obtained following contrast medium in 33. Of the 58 patients 29 underwent selective cerebral angiography. We found in all 63 VA, including two with arterial components; 5 of the 58 patients thus each had two VA. The VA were supratentorial and bilateral in 4 cases; the remaining patient had supra- and infratentorial VA. Of these 5 patients, 4 received intravenous contrast medium and in 2 of them, the second VA was so small that it was detectable only on the contrast-enhanced images. The incidence of double VA in patients receiving contrast medium was 12% (4/33).     

Posterior fossa venous anomaly and ipsilateral acoustic neuroma: two cases

Summary The association of an acoustic neuroma with an ipsilateral venous anomaly or angioma is reported in two patients. In the first, the venous angioma was situated low in the posterior fossa, and was of no significance surgically. In the second, the angioma was strongly attached to the capsule of the tumour. On MRI and angiography the lesion appeared as a large draining vein, encircling the tumour. At operation, extensive dissection of the angioma from the neuroma appeared necessary to prevent venous infarction of the brain stem.     

The natural history of familial cerebral cavernomas: a retrospective MRI study of 40 patients

Our objective was to determine the natural history and prognostic factors of familial forms of cerebral cavernous malformations (CCM). Cavernomas are one of the most common central nervous system vascular malformations. Familial CCM is increasingly diagnosed, but little is known about its natural history. In a national survey, we analysed clinical and MRI features of 173 patients from 57 unrelated French families. Of these 40 had undergone at least two clinical and MRI examinations. Occurrence of haemorrhage, new lesions, change in signal intensity and size of lesions have been studied by comparison between first and last MRI studies. The CCM were classified according to Zabramski et al. Mean follow-up was 3.2 years (range 0.5–6.5 years). We followed 232 cavernomas (mean 5.9 per patient, range 1–17). Serial MRI demonstrated changes in 28 patients (70 %). Bleeding occurred in 21 lesions (9.1 %) in 14 patients (35 %). The haemorrhagic risk was 2.5 % per lesion-year, higher in type I and brain-stem CCM. We saw 23 new lesions appear in 11 patients (27.5 %), with an incidence of 0.2 lesions per patient year. Signal change was observed in 11 patients (27.5 %), in 14 lesions (6 %), while 9 lesions (3.9 %) in 9 patients (22.5 %) changed significantly in size. Received: 20 May 1999/Accepted: 1 September 1999     

Fetal magnetic resonance imaging of the central nervous system: a pictorial essay

Prenatal ultrasonography is the primary screening modality for the evaluation of fetal pathology. Ultrafast fetal MRI is a recent development that examines the fetus in utero. The short acquisition times (as short as 400 ms/slice) allow to picture freeze the fetus without the need for fetal sedation. The high spatial resolution, good contrast-to-noise ratio, and the multiplanar capabilities are especially advantageous in pathologies of the fetal central nervous system (CNS). Fetal MRI currently serves as a second-line imaging tool for complex fetal cerebral malformations and pathologies. Fetal ventriculomegaly, lesions within the posterior fossa, and abnormalities in cerebral myelination, migration, and sulcation are particularly well identified.     

Prenatal brain atrophy due to a giant vein of Galen malformation

Summary We report a full-term newborn girl with a giant vein of Galen malformation and extreme cerebral atrophy of prenatal origin. She presented on the 3rd day of life with intractable congestive heart failure. The diagnosis of the vascular malformation was confirmed by ultrasound and magnetic resonance imaging.     

Vascular anomalies: A pictorial review of nomenclature,diagnosis and treatment

Vascular anomalies, including vascular malformations and tumors, are frequently straightforward to detect; however, accurate diagnosis and appropriate treatment are often challenging. Misdiagnosis of these lesions can lead clinicians in the wrong direction when treating these patients, which can have unfavorable results. This review presents an overview of the classification systems that have been developed for the diagnosis of vascular lesions with a focus on the imaging characteristics. Pictorial examples of each lesion on physical examination, as well as non-invasive and minimally invasive imaging are presented. An overview of the endovascular treatment of these lesions is also given. In some cases, vascular anomalies may be associated with an underlying syndrome and several of the most commonly encountered syndromes are discussed. Understanding of the classification systems, familiarity with the treatment options and knowledge of the associated syndromes are essential for all physicians working with this patient population. The approach to the described entities necessitates an organized multi-disciplinary team effort, with diagnostic imaging playing an increasingly important role in the proper diagnosis and a combined interventional radiologic and surgical treatment method showing promising results.     

Endovascular treatment of brain-stem arteriovenous malformations: safety and efficacy

Our purpose was to evaluate the safety and efficacy of endovascular treatment of brain-stem arteriovenous malformations (AVMs), reviewing six cases managed in the last 5 years. There were four patients who presented with bleeding, one with a progressive neurological deficit and one with obstructive hydrocephalus. Of the six patients, one showed 100%, one 90%, two 75% and two about 50% angiographic obliteration of the AVM after embolisation; the volume decreased about 75% on average. Five patients had a good outcome and one an acceptable outcome, with a mild postprocedure neurological deficit; none had further bleeding during midterm follow-up. Endovascular management of a brain-stem AVM may be an alternative to treatment such as radiosurgery and microsurgery in selected cases. It may be not as risky as previously thought. Embolisation can reduce the size of the AVM and possibly make it more treatable by radiosurgery and decrease the possibility of radiation injury.     

中枢神经系统多原发性及多源性肿瘤的MRI分析

目的 探讨中枢神经系统多原发性及多源性肿瘤的MRI诊断价值。资料与方法回顾性分析3l例经病理证实的中枢神经系统多原发性及多源性肿瘤的MRI资料。结果多原发性肿瘤17例,其中,颅内多发性胶质瘤8例,多发性脑膜瘤2例,椎管内多发性神经纤维瘤4例,神经鞘瘤3例;多源性肿瘤14例,其中10例为神经纤维瘤病合并颅内或椎管内肿瘤,有1例肿瘤细胞类型达到3种。结论MRI对多原发性肿瘤和多源性肿瘤具有重要的诊断价值。     

扩散峰度成像的基本原理及其在脑肿瘤中的应用

扩散峰度成像（DKI）是近年发展起来的一项新的MR扩散加权成像（DWI）技术,不同于传统的DWI及扩散张量成像（DTI）,DKI主要是通过描述组织内水分子扩散运动偏离正态分布的程度,评价组织的微结构,间接反映组织生理、病理情况。DKI目前已广泛应用于中枢神经系统的临床研究,尤其在脑肿瘤方面。对DKI的基本原理及其在脑肿瘤中的临床应用予以综述。     

The spectrum of symptomatic arterialized developmental venous anomalies: case reports

Developmental venous anomaly (DVA) is an anatomical variation of the intracranial venous system, usually without clinical repercussion. In most cases, DVAs are incidentally diagnosed and should be considered as benign conditions. In rare circumstances, DVAs may become symptomatic due to mechanical or flow-related etiologies. The authors present three cases of symptomatic arterialized DVAs: a 28-year-old male with hematoma at the splenium of the corpus callosum and intraventricular hemorrhage, a 53-year-old male patient with a history of epileptic seizures starting recently, and a 25-year-old male patient, previously healthy who started with persistent headaches and hemosiderin deposition in brain parenchyma. These rare cases of arterialized DVAs are conditions that can cause symptoms or show more aggressive behavior with bleeding.     

Miliary brain tuberculosis in an infant

Tuberculosis remains prevalent in developing countries. Central nervous system tuberculosis often occurs secondary to pulmonary tuberculosis, transmitted through the bloodstream, and has a high mortality rate. Meningitis is the most common presentation of central nervous system tuberculosis, followed by tuberculoma, tuberculous brain abscess, and miliary tuberculosis. In this report, we present a case of miliary tuberculosis in a 3 month-old boy. The patient had a fever and was breathless for 1 month. The patient appeared cyanotic, experienced a seizure, and became comatose. Chest computed tomography scan suggested a pulmonary miliary tuberculosis abscess in the right lung and mediastinal lymph node tuberculosis. Brain magnetic resonance imaging showed the lesions were homogeneously enhancing tiny 2-3 mm nodules characteristic of miliary TB. Polymerase chain reaction of the cerebrospinal fluid and sputum samples confirmed tuberculosis. The patient died 1 month after diagnosis.     

Suprasellar cavernous haemangioma: an important differential diagnosis in the diencephalic tumours

We present three cases of suprasellar cavernous haemangioma with characteristic high-field MRI features. Clinical, CT and MRI data were retrospectively analysed. The patients had progressive neurological, endocrinological and visual complaints. In the three cases CT revealed a high-density suprasellar mass. In all cases the combination of a reticulated core of mized signal intensity with a surrounding rim of decreased signal on T1- and T2-weighted MRI scans suggested the presence of a cavernous haemangioma. Two patients underwent surgical biopsy after their first MRI examination. Cavernous haemangiomas located in the suprasellar area may show typical MRI features. Correspondence to: B. Suarez