We report on a 13-year-old girl with late infantile neuronal ceroid lipofuscinosis (NCL) in whom PET scanning with [18F]-2-fluoro-2-deoxy-D-glucose ([18F]/FDG) was performed. Early psychomotor development was normal. At the age of 2 years, neurological signs such as hypotonia and incoordination appeared, followed by visual failure and ataxia. At the age of 4, funduscopic examination showed macular degeneration and papillary atrophy. At the age of 9, myoclonic jerks were observed; subsequently, generalized seizures together with failing vision, mental deterioration, and visual and auditory hallucinations appeared. Brain MRI showed severe cortical and subcortical atrophy. A skin biopsy detected the presence of 'finger-print' inclusions in the cytoplasm of smooth muscle fibers. Late infantile NCL (Jansky-Bielschowsky disease) was diagnosed. FDG/PET revealed a severe reduction of metabolism in all the cortical and subcortical structures. A regional analysis of the distribution of the tracer revealed marked bilateral hypometabolism, particularly in calcarine, lateral, occipital, and temporal cortices and in the thalamus.

Adolescent↗

PubMedDate not supplied

An assisted automated procedure for vessel geometry reconstruction and hemodynamic simulations from clinical imaging.

In this paper a method is described to obtain realistic 3-D geometric models of vascular districts from clinical tomographic 3-D images. The aim is the simulation of individual local hemodynamics by means of computational fluid-dynamics (CFD). As a test case, the method is applied to the carotid bifurcation. Attention is focused on the minimisation of the time demanding costs. The proposed procedure has been automated whenever possible and takes about 2h from the acquisition of the images to the attainment of the simulation results, a time lapse compatible with diagnostic exigency.

Aged↗

PubMedDate not supplied

Correlation of SPECT and PET cardiac images by a surface matching registration technique.

Complementary information provided by Single Photon and Positron Emission Tomography (SPECT and PET) in nuclear cardiology allows a better comprehension of the physiopathology of the heart. In this work a surface matching registration technique is evaluated in the spatial correlation of SPECT and PET cardiac images. The method is based on matching correspondent anatomical surfaces extracted from transmission (TR) SPECT and PET studies, usually performed for attenuation correction. The accuracy of the technique was evaluated by phantom experiments and on patient data (201Tl SPECT and 13NH3 PET perfusion studies). An application of the method is presented for the correlation of SPECT 201Tl perfusion and PET 18FDG metabolic studies in the evaluation of myocardial viability.

Ammonia↗

PubMedDate not supplied

Head holder for PET, CT, and MR studies.

A new head holder for the fixation and repositioning of the patient head in PET, CT, and MR scanners has been designed and tested. With this device, a bidimensional correlation between functional and anatomical brain images can also be obtained. Head fixation and repositioning are achieved using the patient's dental morphology as an anatomical reference. With a dentistic material, a mold of the patient's teeth is obtained in a few minutes. The molding substance rests on a plastic support, fixed to the head holder. Each time the patient undergoes a new study, his/her personal mold is used, ensuring accurate head repositioning. External markers fixed on the head holder (made visible in lateral PET and CT projection images, midsaggital MR images, and also on the axial images) make it possible to record and recognize the angular orientation and the position of the brain in the three-dimensional space, to correlate images of the same patient obtained with different neuroimaging modalities, and to accurately reposition patients for follow-up studies. The head holder was tested on several subjects. Fixation and repositioning accuracy of within 2.5 mm were achieved in the three-dimensional space. Orientation accuracy was 1 degree.

Equipment Design↗

PubMedDate not supplied

Functional MRI: primary motor cortex localization in patients with brain tumors.

PURPOSE: Our goal was (a) to test the ability of functional MRI (fMRI) to localize the hand primary motor cortex in patients with brain neoplasms using a conventional scanner and (b) to compare within the same subject the location and morphology of the activated motor areas in the affected hemisphere with the contralateral ones. METHOD: Seventeen right-handed patients with frontoparietal intra- and extraaxial tumors were studied. Hand motor performance ranged from normal to slight impairment of finger dexterity. The fMRI study was based on a series of FLASH images. Two or three contiguous slices parallel to the bicommissural plane were acquired through the level of frontoparietal cortex. Each patient was requested to perform with each hand a finger-tapping task or a simpler repetitive flexion-extension of the last four fingers. Pseudo-color activation maps were then calculated by a Z-score method and superimposed on high resolution images. RESULTS: Five patients were excluded because of gross motion artifacts. In all other patients, areas of significant signal increase were detected on the precentral gyrus. They had a spot-like appearance, and no substantial side-to-side differences in shape or extension could be observed. In the presence of severe compression of the gyri, a displacement of the activated areas in the affected hemisphere with respect to the contralateral ones was noticeable. CONCLUSION: fMRI localization of the primary motor area using a conventional scanner can be obtained also in patients with brain tumors, although with a lower success rate than in normal volunteer studies, mainly because of subject compliance problems. Areas of significantly increased signal are detectable even in cortex where normal anatomical patterns are lost.

Adolescent↗

PubMedDate not supplied

Focal cerebral lesions found by magnetic resonance imaging in cryptogenic nonrefractory temporal lobe epilepsy patients.

Brain magnetic resonance imaging (MRI) was studied in patients with mild-to-moderate temporal lobe epilepsy (TLE), well controlled by pharmacotherapy, and with normal computed tomographic (CT) scans. Magnetic resonance imaging abnormalities were found in 19 patients; of these, nine had abnormalities in temporomesial regions and four in temporobasal regions. Six patients had white matter MRI lesions of nonspecific significance. The temporomesial MRI lesions were compatible with sclerosis of Ammonis cornu. Patients with this MRI finding had more severe and longer lasting TLE than those without MRI abnormalities. The temporobasal lesions were interpreted as potentially developing brain lesions. Correlation between EEG and MRI findings was good. We conclude that MRI is more useful than CT for diagnosis of patients with mild-to-moderate TLE.

Adult↗

PubMedDate not supplied

Impairment of neocortical metabolism predicts progression in Alzheimer's disease.

Progression rates of Alzheimer's disease (AD) vary considerably, and they are particularly difficult to predict in patients with mild cognitive impairment. We performed a prospective multicenter cohort study in 186 patients with possible or probable AD, mostly with presenile onset. In a cross-sectional analysis at entry, impairment of glucose metabolism in temporoparietal or frontal association areas measured with positron emission tomography was significantly associated with dementia severity, clinical classification as possible versus probable AD, presence of multiple cognitive deficits and history of progression. A prospective longitudinal analysis showed a significant association between initial metabolic impairment and subsequent clinical deterioration. In patients with mild cognitive deficits at entry, the risk of deterioration was up to 4.7 times higher if the metabolism was severely impaired than with mild or absent metabolic impairment. Copyrightz1999S.KargerAG, Basel

Aged↗

PubMedDate not supplied

Isolated amnesia with slow onset and stable course, without ensuing dementia: MRI and PET data and a six-year neuropsychological follow-up.

Patient EDS presented with an amnesic disorder of insidious onset (4 years) that remained stable and restricted to memory functions over a 10-year course. Repeated neuropsychological evaluations over 6 years showed a moderate-to-severe, stable impairment of long-term memory and of memory for public events, and a milder, stable impairment of autobiographic memory and of short-term memory. Language, perception, praxis and 'frontal' functions were fully preserved. MRI showed atrophy of the right hippocampus, of the right mammillary body and of the sylvian fissure (bilaterally, but more marked on the left). On PET scan, metabolic activity in the mesial temporal structures was significantly reduced on the right and was at lower normal levels on the left. The disorder observed in EDS is similar to that recently reported in other patients. Possible etiologies of the selective amnesia observed in EDS are considered and their implications discussed.

Age of Onset↗

PubMedDate not supplied

Correlations between cognitive impairment, middle cerebral artery flow velocity and cortical glucose metabolism in the early phase of Alzheimer's disease.

In a previous transcranial Doppler (TCD) study, we demonstrated a decrease in blood flow velocity in the proximal tract of the middle cerebral artery (MCA) in patients with Alzheimer's disease (AD). In these patients there was also an asymmetry in blood flow velocity which positively correlated with the cognitive asymmetry often seen in the early phase of AD. In this study we found a correlation between the absolute values and asymmetry indexes of MCA blood flow velocity with adjusted metabolic values and asymmetry indexes of the relative cortical frontotemporoparietal (FTP) areas, evaluated by FDG-PET, and with neuropsychological asymmetry indexes. Patients with prevalent visuospatial deficits (right hemisphere dysfunction) showed significant decreases in right MCA blood flow velocity and right FTP cortical glucose hypometabolism, whereas in patients with prevalent language deficits (left hemisphere dysfunction), these signs were observed on the other side. In AD patients, the decrease of blood flow velocity in MCA might be due to reduced metabolic demands in the temporoparietal cortical areas primarily affected by AD.

Aged↗

PubMedDate not supplied

The need of cost-effectiveness evaluation when using high-cost equipment in national health services.

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Axilla↗