Quantified analysis of a carotid angiogram

Summary To compensate for differences in anatomy and magnification, a hand-held programmable calculator remodels the profile of the lateral view of a skull to fit the outline of a reference skull. The statistical analysis of 85 normalized carotid angiograms yields a numbered map of supratentorial structures. It is then possible to obtain, within 20 min and without sophisticated equipment, an objective analysis of any new angiogram.     

Intellectual prognosis of the Dandy-Walker malformation in children: the importance of vermian lobulation

Half of patients with the Dandy-Walker malformation (DWM) have normal intellectual development. We aimed to identify feature on MRI associated with good intellectual prognosis. We reviewed 20 patients with DWM diagnosed on MRI, mean age 14.6+/-9.9 years. We assessed their intellectual development and related it to the MRI features. We found two groups with a statistically different intellectual outcome. All 14 patients with normal intellectual development had a normal lobulation of the vermis, without supratentorial anomalies. Of the six patients with mental retardation, three had an abnormal vermis, together with dysgenesis of the corpus callosum. In the other three, there were normal vermian anatomy with associated anomalies. Normal lobulation of the vermis, in the absence of any supratentorial anomaly, appears to be a good prognostic factor in DWM. Preservation of cerebrocerebellar pathways and neonatal plasticity could explain the normal intellectual development. These findings might be useful in prenatal diagnosis.     

幕上实质型血管母细胞瘤的MRI诊断

目的 探讨幕上实质型血管母细胞瘤的MRI表现特征,以提高其诊断准确率.方法 回顾性分析7例经手术病理证实的幕上实质型血管母细胞瘤的MRI影像学表现.结果 7例幕上实质型血管母细胞瘤均为单发;肿瘤表现为边界尚清楚的圆形或类圆形的等或长T1信号及稍长或长T2信号,强化明显;肿瘤周围存在轻~中度水肿;肿瘤内部或其周边可见血管影.结论 幕上实质型血管母细胞瘤的MRI表现具有一定的特征性.     

成人幕上毛细胞型星形细胞瘤的MRI诊断

目的：探讨成人幕上毛细胞型星形细胞瘤的MRI影像表现。方法：回顾性分析16例病理证实的成人幕上毛细胞型星形细胞瘤的MRI影像资料。结果：16例中单发14例，多发2例。7例肿块位于脑表面者，相邻的颅骨均见弧形受压、变薄。肿块呈囊实性，椭圆形，境界清楚，无瘤周水肿，T1WI呈低信号，T2WI呈混杂高信号，增强后实性部分呈多环状或不规则强化，囊壁强化或无强化。结论：成人幕上大脑半球毛细胞型星形细胞瘤的MRI表现具有一定特征，MRI可提示诊断和指导临床治疗。     

Decreased signal intensity of the middle cerebellar peduncle on diffusion-weighted MRI in patients with large supratentorial lesions

PURPOSE: The purpose of this work was to evaluate signal intensity change of the middle cerebellar peduncles on diffusion-weighted imaging in patients with large supratentorial lesions. METHODS: Signal intensity of the middle cerebellar peduncles was measured using a region of interest in 40 normal control subjects and in 28 patients with moyamoya disease on axial diffusion-weighted imaging with the motion-probing gradient perpendicular to the image. An additional six patients without moyamoya but with large supratentorial sequelae of hemorrhage or infarction were also included. RESULTS: There was no difference in signal intensity between both middle cerebellar peduncles in normal subjects, but lower signal intensity was consistently observed in the contralateral middle cerebellar peduncle in 12 moyamoya patients with large supratentorial lesions in the middle cerebral artery distribution. This finding was observed in the six non-moyamoya patients, too. CONCLUSION: Decreased signal intensity of the contralateral middle cerebellar peduncle might be a remote effect caused by a large supratentorial lesion in a crossed cerebellar fashion.     

幕上原始神经外胚叶瘤的影像学表现

目的 探讨幕上原始神经外胚叶瘤（SPNET）的MRI及CT特征。方法 回顾性分析10例经手术病理证实的SPNET的MRI及CT表现。结果 SPNET的影像学表现有以下特点；（1）肿瘤呈类圆形，边界清楚，病灶周围无水肿或水肿较轻，且大部分位于中线附近及侧脑室旁，少数位于皮层下；（2）MRI示肿瘤实质T1WI呈稍低或等倍，T2WI呈等信号，与脑灰质信号相等，增强较明显。（3）CT示肿瘤实质呈稍高密度，影像学表现与髓母细胞瘤相似。（4）中线附近的肿瘤为实体结构。无囊变；囊变明显的肿瘤多们于皮质下。（5）部分肿瘤内有出血或钙化，有的可见到脑脊液扩散灶。结论 SPNET影像学表现有一定特征。结合其影像学表现及临床症状有助于与其他肿瘤区分。     

Multiple intracranial hydatid cysts: MR findings

Multiple intracranial hydatid cysts are uncommon and usually localized in the supratentorial compartment. We report a case studied by CT and MR of multiple intracranial hydatid cysts scattered in various anatomic sites: supratentorial, infratentorial and also intraventricular. Correspondence to: J. M. Pumar Cebreiro     

幕上脑血管病与继发性大脑脚瓦勒变性的关系(附272例报告)

目的 观察幕上脑血管病后继发的瓦勒变性(WD)的发生特点,探讨WD与临床表现的关系.方法 回顾性调查272例幕上脑血管病患者的CT扫描结果,分析病变分布的特点,测量患病后大脑脚的变化,并进行近期日常生活活动能力量表(ADL)测评,所得结果进行统计学分析.结果 幕上脑血管病继发WD者共74例,发生率27.2%,其病灶侧大脑脚宽度明显小于健侧(P＜0.01),而ADL评分明显高于非WD组(f＜0.01).结论 中枢神经系统损伤后与周围神经一样可以出现继发性WD,但不易恢复;幕上脑血管病继发大脑脚WD对日常生活能力有影响;头颅CT随访有助于指导临床医生制定正确的康复计划,促进患者功能恢复.     

Accuracy of the detection of infratentorial stroke lesions using perfusion CT: an experimenter-blinded study

Introduction  

Although perfusion CT (PCT) for the detection of supratentorial stroke is well established, there is a dearth of evidence of its effectiveness in the detection of infratentorial stroke. Hence, this study compared sensitivity, specificity, and accuracy of PCT maps between infratentorial and supratentorial stroke lesions.     

Contrast enhanced CT scan and radionuclide brain scan in supratentorial gliomas.

The preoperative contrast enhanced CT and radionuclide brain scans of 60 patients with surgically verified supratentorial astrocytomas were evaluated and compared. Results indicated that the mechanisms of contrast enhancement and radionuclide uptake are identical in the detection of supratentorial gliomas. These diagnostic methods apparently mirror the integrity of the blood-brain barrier and therefore can be useful in assessing the degree of malignancy of supratentorial gliomas. However, lesions with an intact blood-brain barrier will be missed with radionuclide imaging. These parenchymal abnormalities and/or the associated mass effect will be detected with contrast enhanced computed tomography. These findings firmly establish contrast enhanced computed tomography. These findings firmly establish contrast enhanced CT as the primary investigate tool in the suspected brain tumor.     

Crossed cerebellar diaschisis and crossed cerebellar atrophy: correlation of MR findings, clinical symptoms, and supratentorial diseases in 26 patients.

Crossed cerebellar diaschisis is a condition in which cerebellar hypometabolism is ascribed to functional disconnection of the contralateral hemisphere from the cerebral cortex. Interruption of the cerebropontine-cerebellar pathway is thought to be the most likely mechanism of this remote transneuronal metabolic depression. This phenomenon can be diagnosed by positron emission tomography, as there is hypometabolism in the affected cerebellar hemisphere. The morphologic features of the affected cerebellar hemisphere in patients with the diagnosis of crossed cerebellar diaschisis have not previously been studied by MR imaging. We retrospectively reviewed 26 patients in whom the diagnosis of crossed cerebellar diaschisis was suggested by positron emission tomography; these patients also had MR studies. In all 26 patients, supratentorial diseases were documented by MR imaging. Twenty-four of the 26 patients had a pathologic diagnosis. Detailed clinical history was also obtained for all patients. MR findings of morphologic change in the affected cerebellum were correlated with the patient's clinical symptoms and supratentorial disease. Of the 26 patients, eight had cerebellar atrophy; the remaining 18 patients showed no MR abnormality of the affected cerebellum. In the 18 in whom no atrophy was seen on MR imaging, the majority of the supratentorial lesions were tumors. The eight patients in whom cerebellar atrophy was demonstrated usually had significant contralateral supratentorial hemispheric atrophy. The patients with atrophy were also generally younger (average age, 14 years) than the 18 patients without cerebellar atrophy (average age, 42 years). Our experience shows that a significant number of patients with crossed cerebellar diaschisis have morphologic changes of cerebellar atrophy shown by MR imaging. These patients usually have significant contralateral supratentorial hemispheric atrophy.     

Replicability of diffusion tensor imaging measurements of fractional anisotropy and trace in brain

PURPOSE: To evaluate within-scanner and between-scanner reliability of fractional anisotropy (FA) and trace (sum of the diagonal elements of the diffusion tensor) as measured by diffusion tensor imaging (DTI). MATERIALS AND METHODS: Ten young healthy adults were scanned on three separate days, on two different systems made by the same manufacturer. One scan was acquired at one site, and two scans were acquired on two different occasions on another scanner at another site. Three levels of analysis were used to compare the DTI metrics: 1) a voxel-by-voxel analysis of all supratentorial brain (gray matter + white matter + cerebrospinal fluid) and of supratentorial white matter; 2) a slice-by-slice analysis of supratentorial white matter; and 3) a single-region analysis of the corpus callosum. RESULTS: The voxel-by-voxel analysis of all supratentorial brain found that FA and trace measures and correlations were equivalently and significantly higher within than across scanners. For supratentorial white matter, FA was similar within and across scanners, whereas trace demonstrated across-scanner bias. A similar pattern was observed for the slice-by-slice comparison. For the single-region analysis of the corpus callosum, within-scanner FA and trace measures were highly reproducible for FA (CV = 1.9%) and trace (CV = 2.6%), but both DTI measures showed a systematic mean bias across scanners (CV = 4.5% for FA and CV = 7.5% for trace). CONCLUSION: These estimates of measurement variation and scanner bias can be used to predict effect sizes for longitudinal and multisite studies using diffusion tensor imaging.     

幕上原始神经外胚层肿瘤的CT、MRI和病理分析

目的探讨幕上原始神经外胚层肿瘤（PNET）的CT及MRI特点,以提高影像学诊断的准确性。资料与方法分析经手术病理证实的8例PNET的CT及MRI表现。结果8例PNET分别位于幕上大脑半球的额顶、额颞、枕叶、胼胝体区,病灶普遍较大,多为偏实性肿瘤,边界清晰,瘤周水肿较轻,其中病灶内囊变4例,合并出血3例,肿瘤T1WI呈稍低信号,T2WI呈稍高信号4例,T1WI、T2WI呈混杂信号3例,2例DWI显示呈高信号。增强检查肿瘤可表现为不均一强化、不规则“印戒”样强化,2例显示沿室管膜播散。结论PNET影像学表现有一定特征,影像学表现结合临床症状有助于与其他肿瘤区分。     

Computed tomography in astrocytomas. A statistical analysis of the parameters of malignancy and the positive contrast-enhanced CT scan.

Four histopathological indices of malignancy--cellularity, pleomorphism, vascularity, and necrosis--were correlated with the positive-contrast CT scan in 84 patients with pathologically proved astrocytoma. Vascularity and necrosis correlated best with the scan in supratentorial tumors, while vascularity and cellularity correlated significantly with the scan in cerebellar astrocytomas. These findings indicate that the degree of malignancy of a supratentorial astrocytoma can be inferred from the contrast-enhanced scan, but that this is not generally possible with posterior fossa tumors.     

Magnetic Resonance Imaging patterns in central nervous system lymphomas: A pictorial review

Five distinctive Magnetic Resonance Imaging (MRI) patterns of Central Nervous System Lymphomas (CNSL) are introduced in this pictorial essay - in an attempt to differentiate lymphoma from other abnormalities with similar MRI appearance, − namely a. solitary supratentorial, b. multiple supratentorial, c. infratentorial, d. intravascular, and e. extraparencymal. Recognition of a specific imaging pattern on brain MR imaging, may facilitate the early diagnosis and prompt treatment initiation, thus improving prognosis of brain lymphoma.     

Computed tomographic findings in progressive supranuclear palsy

Summary CT findings of 6 patients with progressive supranuclear palsy (PSP) are described, with emphasis on their supratentorial changes in comparison with those of control subjects and patients with Parkinson's disease (PD). As estimated from CT films, the lateral ventricles, third ventricle and prepontine cistern were significantly enlarged in PSP patients compared with both controls and PD patients. It is suggested that the patients with PSP have not only infratentorial but also supratentorial lesions.     

幕上间变型室管膜瘤的MRI表现

目的: 探讨幕上室管膜瘤的MRI表现及其诊断价值.材料和方法:回顾性分析11例经病理证实间变型室管膜瘤MRI表现.结果:11例肿瘤均位于脑实质,其中侧脑室旁9例.肿瘤呈囊实性9例和实性2例,呈长T1长T2信号,瘤内出血4例,T1WI、T2WI呈结节状高信号,囊变呈更长T2信号,瘤周II度水肿11例.增强扫描实性部分及囊壁不均匀显著增强,囊变及出血区无增强.结论:幕上间变型室管膜瘤的MRI表现有一定的特征性,大囊、多囊变、实性肿块周边出血、实性部分明显增强是瘤体的常见征象.     

幕上纤维型星形细胞瘤的CT和MRI诊断

目的:探讨幕上纤维型星形细胞瘤的CT和MR表现特征.方法:回顾性分析26例经手术、病理证实的幕上纤维型星形细胞瘤的CT、MR表现特点.26例均行MR平扫及增强扫描,16例行CT平扫.结果:本组肿瘤好发于大脑半球深部,病变主要累及髓质,以额颞叶为主(23例,88%),部分侵犯邻近皮质.26例中17例(65%)病变为弥漫性...     

Isotope scanning of brain tumors in children

A total of 31 brain tumors (21 verified histologically, 10 by clinical and neuroradiologic methods) in children aged from 7 months to 13 years were investigated by scintigraphy with ^99mTc as a radioactive isotope tracer. There were 16 supratentorial and 15 infratentorial tumors. The supratentorial tumors were detected in 88%, and the infratentorial in 13%, of cases by brain isotope scanning. The advantages and disadvantages of the method are discussed.     

MR of cerebellar cortical dysplasia.

MR imaging findings are described in four patients with cerebellar cortical dysplasia. Typically, cerebellar disorganized folia were seen as an irregular bumpy gray-white matter interface. In addition, cystlike cortical abnormalities were observed in two patients and associated supratentorial developmental abnormalities were seen in three patients. To our knowledge, cerebellar cortical dysplasia without supratentorial abnormalities, as seen in one patient, has not been reported before. We suggest that cerebellar cortical dysplasia represents a spectrum of abnormalities ranging from mild to extensive in severity.