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1.
The authors report a 43-year-old patient with histopathologically proven cerebral Whipple's disease. Magnetic resonance imaging (MRI) revealed a multilayered left frontal lesion without mass effect, no perifocal brain edema, no contrast enhancement, and a thin shell of fluid signal that presented as an incomplete, open ring. An [11C]methionine positron emission tomography (PET) study showed low uptake below the threshold that is characteristic for brain tumors. In precise co-registration to the MR images, the PET data showed that increased uptake was mainly located in the direct adjacent part of the MRI lesion. The fluid signal on MRI corresponded to the extensive outflow of fluid from the lesion, which was observed during neurosurgical resection, and also to the neuropathological findings. The authors conclude that this cerebral manifestation of Whipple's disease made a unique and hitherto undescribed appearance on MRI; uptake pattern of PET amino acid tracer may help in the preoperative distinction of inflammatory from neoplastic lesions.  相似文献   

2.
Dyke–Davidoff–Masson syndrome (DDMS) is a rare epilepsy syndrome that is characterized by cerebral hemiatrophy, homolateral skull hyperplasia, hyperpneumatization of the paranasal sinuses, seizures with or without mental retardation, and contralateral hemiparesis. We describe a case of DDMS in a 40-year-old female who had complex partial seizures with occasional secondary generalization since the age of 4 years. Her seizure frequency was 10–20 seizures/month even though she took four antiepileptic drugs. We applied magnetic resonance imaging (MRI), positron emission tomography (PET), functional MRI, and invasive electroencephalography (EEG) to define her epileptogenic and functional zones. Brain MRI showed prominent atrophy in the left frontal dorsal and lateral regions and mild atrophy of the left superior temporal gyrus and left parietal gyri. Interictal PET revealed decreased glucose metabolism in the atrophic regions. Functional MRI demonstrated that the inferior frontal and inferior parieto-occipital regions of the right hemisphere were activated by language testing. Invasive EEG revealed that the left lateral temporal lobe was the sole source of her seizures. Our results imply that the “metabolic border zone” rather than the atrophic region plays an important role in seizure activity, and that reorganization of functional zones occur after cerebral damage early in life.  相似文献   

3.
Gliomas represent approximately one-third of all intracranial tumors in adults and commonly present clinically with seizures. We report two seizure patients with paradoxical imaging findings on preoperative grading of their cerebral gliomas. A 53-year-old man with a history of temporal lobe epilepsy originating from a mass in the right medial temporal region (patient 1) and a 44-year-old man with a history of predominantly left sided sensory seizures with a mass in the right posterior parietal region (patient 2) underwent presurgical evaluation including MRI and glucose PET, followed by surgery to remove cerebral tumors associated with seizure onset. Preoperatively, patient 1 had a homogenous non-enhancing lesion on MRI and hypometabolism on PET imaging, suggesting a low-grade tumor. Postoperative histopathology was consistent with a glioblastoma multiforme (grade IV). Patient 2 had a heterogeneous lesion with cyst formation, edema, and contrast enhancement on preoperative MRI imaging, and interictal hypermetabolism on PET scan, thus suggesting a high-grade tumor. Postoperative histopathology was consistent with an oligodendroglioma (grade II) without anaplastic features. We conclude preoperative grading of cerebral gliomas may be inaccurate occasionally even in cases with concordant structural and functional imaging findings. This should be considered when counseling patients.  相似文献   

4.
Fourteen patients with spinocerebellar degeneration (SCD) were subjected to MRI and PET studies. The quantitative MRI data revealed significant cerebellar and pontine atrophy in the patients with olivopontocerebellar atrophy (OPCA), and cerebellar atrophy in the patients with late cerebellar cortical atrophy (LCCA). We failed to demonstrate significant differences in the pons between LCCA patients and normal controls. PET measurements revealed decreases in cerebral oxygen metabolic rate (CMRO2) in the cerebellar hemisphere and vermis in both groups of patients. The markedly decreased cerebral blood flow (CBF) and CMRO2 in the pons were found only in the patients with OPCA. PET data corrected for the tissue shrinkage on the basis of MRI morphometry indicated a net reduction in cerebellar CMRO2 and CBE The present study has demonstrated that a combination of functional and anatomical data offers further evidence in favour of the current acceptable classification of SCD based on clinicopathological grounds. Our data further suggest that the amount of atrophy in the cerebellum could not fully account for the decreased metabolic rates observed in PET studies.  相似文献   

5.
A 35-year-old man presented with partial seizures 10 years after resection of a left-sided glioblastoma multiforme. At the old operative site MRI demonstrated extensive cortical and white matter gadolinium enhancement, and PET showed hypermetabolism. Biopsy of the area was postponed when MRS showed a normal biochemical spectrum. MRI and PET abnormalities resolved after control of the seizures. MRS is noninvasive and can provide essential information in the management of patients with seizures and previously treated cerebral neoplasms.  相似文献   

6.
《Brain & development》1998,20(5):295-301
The clinical, PET (positron emission tomography) and MRI (magnetic resonance imaging) findings of brain studies in eight patients, previously diagnosed to have glutaric aciduria type 1, were retrospectively reviewed. The neurological findings typically consisted of variable degrees of dementia and extrapyramidal symptoms (dystonia, choreoathetosis and rigidity). Both MRI and PET showed involvement of the putamina in all the patients. The PET scan demonstrated lesions in the head of the caudate nuclei in all of the patients. Brain atrophy, and in particular the characteristically-enlarged Sylvian fissures, was better demonstrated by MRI. On the other hand, the cerebral cortex and thalamic structures were found to be normal by MRI in all patients, whereas PET scan showed decreased uptake in the cerebral cortex in seven, and in the thalami in three patients. Correlation between imaging and clinical findings was found to be good when both PET scan and MRI findings of the brain were taken into consideration. Therefore, the functional (PET) and structural (MRI) studies of the brain were complementary in the imaging evaluation of glutaric aciduria type 1.  相似文献   

7.
BACKGROUND AND PURPOSE: Cerebral microangiopathy, indicated on MRI by lacunar infarctions (LI) and deep white matter lesions (DWML), is said to lead to vascular dementia. METHODS: Fifty-seven patients with proven cerebral microangiopathy were assessed for changes in regional cerebral blood flow (rCBF) and glucose metabolism (rMRGlu) and compared with 19 age-matched controls. The findings were correlated with results of extensive neuropsychological testing, as well as with MRI findings. A special head holder ensured reproducibility of positioning during rCBF (single-photon emission CT [SPECT]), rMRGlu (positron emission tomography [PET]), and MR imaging. White matter and cortex were quantified with regions of interest defined on MRI and superimposed to corresponding PET/SPECT slices. LI and DWML were graded by number and extent. RESULTS: Even with severe DWML and multiple LI, rCBF and rMRGlu values were not reduced. ANOVAs identified brain atrophy and neuropsychological deficits as the main determinants for reduced rCBF and rMRGlu values in both cortex and white matter. Neuropsychological deficits correlated well with decreased rCBF and rMRGlu, whereas MRI patterns such as LI and DWML did not. Factor analysis revealed no correlation of LI and DWML with rCBF, rMRGlu, atrophy, and neuropsychological deficits, showing instead positive correlations between rCBF, rMRGlu, and neuropsychological performance and negative correlations of the latter 3 with brain atrophy. CONCLUSIONS: From these data, we conclude that LI and DWML are epiphenomena that may morphologically characterize cerebral microangiopathy but do not in themselves indicate cognitive impairment. Dementia or neuropsychological deficits, by contrast, are reflected exclusively by functional imaging parameters (rCBF, rMRGlu) and cerebral atrophy.  相似文献   

8.
目的探讨MRI联合~(18)F-脱氧葡萄糖(~(18)F-FDG)PET和~(11)C-蛋氨酸(~(11)C-MET)PET显像对颅内肿胀性脱髓鞘病变与胶质瘤的鉴别诊断价值。方法纳入经病理学直接证实或内科保守治疗间接证实的14例颅内肿胀性脱髓鞘病变患者和17例胶质瘤患者,采用MRI观察病变与周围正常脑组织界限,T1WI、T2WI和扩散加权成像(DWI)信号强度,强化征象(包括环状强化和开环状强化等),占位效应,周围脑水肿,病变中心静脉扩张,胼胝体受累,病变中心坏死,灰质受累情况;~(18)F-FDG PET和~(11)C-MET PET显像对代谢程度进行视觉分析。结果 MRI显示,颅内肿胀性脱髓鞘病变患者占位效应0级8例(8/14)、Ⅰ级4例(4/14)、Ⅱ级1例(1/14)、Ⅲ级1例(1/14),周围脑水肿Ⅰ度12例(12/14)、Ⅱ度2例(2/14);胶质瘤患者占位效应0级2例(2/17)、Ⅰ级6例(6/17)、Ⅱ级7例(7/17)、Ⅲ级2例(2/17),周围脑水肿Ⅰ度7例(7/17)、Ⅱ度10例(10/17),组间差异均有统计学意义(Fisher确切概率法:P=0.032,0.024)。~(18)F-FDG PET和~(11)C-MET PET显像对颅内肿胀性脱髓鞘病变与胶质瘤的鉴别诊断差异无统计学意义(Fisher确切概率法:P=0.182,0.081)。结论 MRI显示的占位效应和周围脑水肿可以用于鉴别诊断颅内肿胀性脱髓鞘疾病与胶质瘤,PET-CT对症状类似胶质瘤的颅内肿胀性脱髓鞘病变无明确诊断价值。  相似文献   

9.
阿尔茨海默病~(18)F-FDG PET显像诊断的研究   总被引:1,自引:0,他引:1  
目的 探讨阿尔茨海默病(AD)脑葡萄糖代谢及其18F-脱氧葡萄糖正电子发射计算机断层扫描(18F-FDG PET)显像的影像学特征和PET诊断标准。方法 静脉注射18F-FDG后行脑断层显像,检查13例 AD、13例非AD痴呆及13例正常人。获得纹状体、丘脑、黑质、顶叶、颞叶、额叶、枕叶、海马单位面积放射性计数与小脑计数的比值(Rcl/cb),进行半定量分析,并与MR进行对照。结果AD患者PET异常率为100%,MR异常者占10/13。PET显像特征:①对称性双侧颞顶叶及海马伴额叶或枕叶代谢减低占9例(9/13);②双侧颞叶对称性代谢减低伴海马或额叶代谢下降占3例(3/13);③双顶叶对称性代谢降低1例(1/13)。12例(12/13)非AD痴呆表现为不对称、多发性代谢降低,降低区位于黑质、纹状体、丘脑及脑皮质区,MR异常率为11/13。结论 在除外脑内结构特异性损害基础上,PET发现对称性双颞顶叶、海马或颞叶、顶叶,伴或不伴枕叶、额叶代谢下降,可诊断AD。PET对AD早期诊断及鉴别诊断具有临床意义。  相似文献   

10.
Fabry disease is an X-linked recessive deficiency of lysosomal alpha-galactosidase A associated with an increased risk of early onset cerebrovascular disease. The disorder is reported to affect the posterior circulation predominantly. This hypothesis was investigated directly by the measurement of regional cerebral blood flow with positron emission tomography (PET). Resting regional cerebral blood flow (rCBF) in 26 hemizygous patients with Fabry disease and 10 control participants was examined using H(2)15O and PET. Statistical parametric mapping (SPM(t), SPM99) and PET images of patients and controls were produced. Significantly increased SPM(t) clusters were then color coded and blended with a coregistered T1 magnetic resonance imaging (MRI) template. Cerebral arterial territory maps were digitized and rescaled. Custom OpenGL and ImageVision Library C++ code was written to allow a first-order affine transformation of the blended SPM(t) and MRI template onto the arterial territory map. The affine transformation was constrained by choosing corresponding cerebral landmark "tie points" between the SPM(t) [symbol: see text] MRI template images and the cerebral arterial territory maps. The data demonstrated that the posterior circulation is the predominant arterial territory with a significantly increased rCBF in Fabry disease. No arterial distribution had a decreased rCBF.  相似文献   

11.
We examined a total of 16 children with epileptic encephalopathy using fluo-rine-18-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission computed tomography (PET), magnetic resonance imaging (MRI) and electroencephalography. Children with infantile spasms showed significant mental retardation, severely abnormal electroencephalogram recordings, and bilateral diffuse cerebral cortex hypometabolism with 18F-FDG PET imaging. MRI in these cases showed brain atrophy, multi-micropolygyria, macrogyria, and porencephalia. In cases with Len-nox-Gastaut syndrome, 18F-FDG PET showed bilateral diffuse glucose hypometabolism, while MRI showed cortical atrophy, heterotopic gray matter and tuberous sclerosis. MRI in cases with myoclonic encephalopathy demonstrated bilateral frontal and temporal cortical and white matter atrophy and 18F-FDG PET imaging showed bilateral frontal lobe atrophy with reduced bilateral frontal cortex, occipital cortex, temporal cortex and cerebellar glucose uptake. In children who could not be clearly classified, MRI demonstrated cerebral cortical atrophy and 18F-FDG PET exhibited multifocal glucose hypometabolism. Overall, this study demonstrated that the degree of brain metabolic abnormality was consistent with clinical seizure severity. In addition, 18F-FDG PET imaging after treatment was consistent with clinical outcomes. These findings indicate that 18F-FDG PET can be used to assess the severity of brain injury and prognosis in children with epileptic encephalopathy.  相似文献   

12.
OBJECTIVE: To study the time-related changes in cerebral metabolic rate of glucose (CMRglc) in MS patients and to correlate these with changes in MRI lesion load and disability. BACKGROUND: Measurements of MRI lesion load and neurologic disability are used widely to monitor disease progression in longitudinal studies of MS patients, but little is known about the associated changes in cerebral neural function. METHODS: The authors studied 10 patients with clinically definite MS who underwent serial measurements of CMRglc, MRI T2-weighted total lesion area (TLA), and clinical evaluation of disability (Expanded Disability Status Scale [EDSS]) over a period of approximately 2 years (three examinations). CMRglc was calculated using PET and 18-fluorodeoxyglucose (FDG). RESULTS: The global cortical CMRglc decreased with time (p<0.001) and the most pronounced reductions of CMRglc were detected in frontal and parietal cortical areas. There was a statistically significant increase of disability (p<0.01) and TLA (p<0.05) measurements during the study, but changes in CMRglc were not correlated to changes in TLA and EDSS. CONCLUSIONS: Global cortical cerebral metabolism in MS is decreased significantly during a 2-year observation period, suggesting a deterioration of cortical activity with disease progression. The time-related changes of cortical CMRglc are statistically stronger than changes in TLA measurements and neurologic disability, and might be a useful secondary measure of treatment efficacy.  相似文献   

13.
The clinical data and the imaging findings of the positron emission tomography (PET) and the magnetic resonance imaging (MRI) studies in five patients, previously diagnosed to have propionic acidemia, were retrospectively reviewed. The patients were all normal at birth. The first clinical signs, typically hypotonia and failure to thrive, appeared during the first 2 years of life. With progression of the disease, the neurological findings consisted of variable degrees of dementia and extrapyramidal symptoms, notably dystonia, choreoathetosis and rigidity of variable degrees. Initial cerebral PET and MRI studies were normal. Follow-up MRI examinations showed progressive basal ganglia degeneration, with evidence of atrophy and signal abnormalities within the caudate nuclei and the putamina. The thalamic structures were normal. The PET studies demonstrated increased uptake in the basal ganglia and thalami, followed by decreased uptake in the basal ganglia at a later stage of the disease. The structural (MRI) and the functional (PET) studies of the brain were found to be complementary in the evaluation of propionic acidemia, and were in good correlation with the clinical findings.  相似文献   

14.
BACKGROUND AND PURPOSE: Early and accurate assessments of cerebral ischemia allow therapy to be tailored to individual stroke patients. We examined the feasibility of using a novel method for measuring cerebral blood flow (CBF) of ischemic tissue based on MRI after middle cerebral artery occlusion (MCAO). Moreover, the regional correlations between CBF and cerebral blood volume (CBV) were investigated in the regions with acute ischemic stroke. METHODS: CBF and CBV were measured before and after MCAO or reperfusion by positron emission tomography (PET) in 13 pigs. Just after the PET scans, CBF and CBV were measured by MR bolus tracking and were compared with results obtained by PET at 6 hours after permanent MCAO or reperfusion. The infarction was verified histologically. RESULTS: The MR method yielded parametric CBF and CBV maps with tissue contrast in good agreement with parametric PET images, which demonstrated hypoperfused and hyperperfused areas after MCAO or reperfusion. Both MRI and PET technology showed that CBF values below 60% of the contralateral value induced a reduction of CBV, which committed the tissue to infarction. CONCLUSIONS: The novel MR method provides accurate measurement of CBF and CBV in acute stroke and hence gives useful information for planning the appropriate therapeutic intervention.  相似文献   

15.
Cerebral oxygen metabolism in idiopathic-normal pressure hydrocephalus   总被引:1,自引:0,他引:1  
OBJECTIVE: To distinguish idiopathic-normal pressure hydrocephalus (i-NPH) from the elder with brain atrophy is difficult. This investigation was undertaken to determine the cerebral oxygen metabolism and the cerebral blood flow using positron emission tomography (PET) in patients with i-NPH. Comparison of the variables between i-NPH patients and the age-comparable control with asymptomatic ventricular dilatation were performed. METHODS: Nineteen patients were studied. Nine i-NPH patients with a mean age of 74.8 +/- 1.8 years (mean +/- SD) were examined using PET. The subjects who underwent a ventriculoperitoneal shunt (VPS) had the triad of NPH and ventricular dilatation on computed tomography (CT) and/or magnetic resonance imaging (MRI). The results of the PET study were compared with those for ten age-comparable controls (74.8 +/- 5.5 years) with asymptomatic ventricular dilatation and no severe cerebrovascular disease on MRI and magnetic resonance angiography (MRA). The PET study included analyses of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional oxygen extraction fraction (rOEF) and regional cerebral metabolic rate of oxygen (rCMRO(2)). RESULTS: In i-NPH, rCBF tended to decrease in the frontal lobe and the basal ganglia. rCMRO(2) in the frontal lobe of i-NPH was significantly higher than that in the controls (p<0.05 by Student's t-test), although rCMRO(2) in the basal ganglia of i-NPH was reduced. rCBV and rOEF showed no significant differences. CONCLUSION: Reduction of oxygen metabolism in the basal ganglia might be one of the factors causing symptoms in i-NPH. Particular pattern of cerebral oxygen metabolism in i-NPH was not obvious in the present study.  相似文献   

16.
In 10 patients with malignant gliomas, the intracerebral distribution of [99mTc]-hexamethylpropylene-amine oxime [( 99mTc]-HM-PAO) was studied with single photon emission computed tomography (SPECT) in comparison with C15O2 steady-state inhalation technique to measure cerebral blood flow using positron emission tomography (PET). In all instances, the cerebral [99mTc]-HM-PAO distribution was comparable with the regional pattern of cerebral blood flow (rCBF) observed with PET. This was confirmed by a significant correlation of tumor to cortex and tumor to white matter ratios between these two experimental methods. However, the contrast between high and low activity regions in the SPECT scans was significantly less than that in the PET scans. Contrast enhancement of the SPECT scans was accomplished using a correction formula proposed by Lassen.  相似文献   

17.
Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) with image acquisition at multiple inversion times is a noninvasive ASL technique able to compensate for spatial heterogeneities in transit times caused by collateral blood flow in patients with severe stenosis of the cerebropetal blood vessels. Our aim was to compare ASL-MRI and H215O positron emission tomography (PET), the gold standard for cerebral blood flow (CBF) assessment, in patients with a symptomatic internal carotid artery (ICA) occlusion. Fourteen patients (63±14 years) with a symptomatic ICA occlusion underwent both ASL-MRI and H215O PET. The ASL-MRI was performed using a pulsed STAR labeling technique at multiple inversion times within 7 days of the PET. The CBF was measured in the gray-matter of the anterior, middle and posterior cerebral artery, and white-matter. Both PET and ASL-MRI showed a significantly decreased CBF in the gray-matter of the middle cerebral artery in the hemisphere ipsilateral to the ICA occlusion. The average gray-matter CBF measured with ASL-MRI (71.8±4.3 mL/min/100 g) was higher (P<0.01) than measured with H215O PET (43.1±1.0 mL/min/100 g). In conclusion, ASL-MRI at multiple TIs is capable of depicting areas of regions with low CBF in patients with an occlusion of the ICA, although a systematic overestimation of CBF relative to H215O PET was noted.  相似文献   

18.
Diagnosis of neurofibromatosis 1 is based on clinical criteria. In a large number of children with neurofibromatosis 1, magnetic resonance imaging (MRI) reveals high-signal T(2)-weighted intensities in different brain regions, defined as unidentified bright objects. These lesions are asymptomatic; most of them regress spontaneously with age, but the presence of contrast enhancement or mass effect in them usually strongly suggests an increased risk of proliferative changes. To date, few studies have focused on evoked potentials in patients with neurofibromatosis 1, and the reported abnormalities did not have significant clinical correlations. We describe the clinical and instrumental (MRI and evoked potentials) follow-up of three patients with neurofibromatosis 1. MRI and evoked potentials showed subclinical involvement of the central nervous system. Some MRI T(2)-weighted hyperintensities showed enhancement and mass effect of uncertain significance. During follow-up, the MRI lesions spontaneously decreased in size or enhancement, allowing us to exclude the hypothesis of proliferative lesions; in the same way, some asymptomatic evoked potential abnormalities disappeared. These findings suggest that both MRI and evoked potentials could be useful in the detection and monitoring of cerebral complications of neurofibromatosis 1.  相似文献   

19.
Purpose: Long‐term epilepsy associated tumors (LEATs) are a frequent cause of drug‐resistant partial epilepsy. A reliable tumor diagnosis has an important impact on therapeutic strategies and prognosis in patients with epilepsy, but often is difficult by magnetic resonance imaging (MRI) only. Herein we analyzed a large LEAT cohort investigated by 18fluoroethyl‐l ‐tyrosine–positron emission tomography (FET‐PET). Methods: Thirty‐six patients with chronic partial epilepsy and a LEAT‐suspect MRI lesion were analyzed by FET‐PET using visual inspection and quantitative analysis of standard uptake values (SUV). PET results were correlated with clinical and histopathologic data. Results: FET‐PET study was positive in 22 of 36 analyzed lesions and in 14 of 22 histologically verified LEAT lesions. The precise World Health Organization (WHO) tumoral entity was not predicted by FET‐PET. Notably, FET uptake correlated strikingly with age at epilepsy onset (p = 0.001). Further correlations were seen for age at surgery (p = 0.007) and gadolinium‐contrast enhancement on MRI (p < 0.05). Discussion: FET‐PET is a helpful tool for LEAT diagnosis, particularly when MRI readings are ambiguous. FET uptake, which is likely mediated by the l ‐amino acid transporter (LAT) family, might indicate a principally important biologic property of certain LEATs, since LAT molecules also are involved in cell growth regulation.  相似文献   

20.
Creutzfeldt-Jakob disease (CJD) causes diffuse neurological symptoms, but asymmetric lesions have been found on conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI). Less often, position emission tomography (PET) scanning can also reveal asymmetric lesions in patients with CJD. Such imaging may mislead clinicians. The authors present a case of a woman with CJD who was diagnosed as having suffered a stroke because she had asymmetric T2-weighted imaging (T2WI) MRI abnormalities that were interpreted as a stroke. It was noted that the patient had clinical features consistent with CJD, including rapidly progressive dementia, myoclonus, cerebellar dysfunction, and pyramidal and extrapyramidal signs. This diagnosis was supported by periodic epileptiform discharges on the electroencephalogram (EEG) and by elevated 14-3-3 protein in the cerebrospinal fluid. MRI T2WI and DWI showed dramatically asymmetric abnormalities involving the left cortex. A PET study found decreased metabolism in the left cerebral and right cerebellar hemispheres. The patient's clinical, EEG, and laboratory data were all consistent with CJD, not other diseases, but the MRI and PET had atypical, asymmetric findings. This case demonstrates that CJD should be considered in the differential diagnosis of patients with rapidly progressive neurological decline, even if they have asymmetric imaging findings.  相似文献   

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