Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Structural MRI”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1998

Intracranial chondrosarcoma: review of the literature and report of 15 cases.

The available data in the literature (177 cases), two current clinical patients, and cases which occurred in The Netherlands (13) were reviewed concerning the clinical presentation, pathological features, radiological data, and treatment options of chondrosarcoma of the cranial base. The mean age of patients was 37 years, the male/female ratio 1:1.1. The most frequent complaints were diplopia with oculomotor disorders (51%), headache (31%), and decreased hearing, dizziness, and tinnitus with statoacusticus dysfunction (21%). The mean duration of symptoms before diagnosis was 27 months. The chondrosarcomas were located in the petrosal bone in 37% (47 cases), in the occipital bone and clivus in 23% (30 cases), in the sphenoid bone in 20% (25 cases) and to a lesser extent in frontal, ethmoidal, and parietal bones (14%). In 6% (eight cases) the primary location was in dural tissue. Radiological examinations showed bone destruction and variable calcification (CT), involvement of neuronal and vascular structures (MRI), and mostly hypovascularity on angiography. On histological examination 51% of tumours were classified as grade I, 11% grade II, 30% mesenchymal, and 8% myxoid. The mesenchymal type was the most malignant as illustrated by a strong tendency to intradural and cerebral growth and possibly occurrence in younger age groups. The treatment of choice until recently was surgery because of the critical location and local aggressive nature. Regrowth of tumour after surgery occurred in 53% of the patients (average after 32 months). Charged particle irradiation gave a five year survival of 83-94% and a local control rate of 78%-91%. Both in surgery and radiotherapy there is treatment related morbidity and mortality that should be considered when offering these therapies. Recent promising results imply that charged particle radiotherapy, in combination with surgery, may be the therapeutical choice of the future.

Adolescent↗
PubMed1989

Very-low-birth-weight, preterm infants with or without intracranial hemorrhage. Neurologic, cognitive and cranial MRI correlations at 4-8-year follow-up.

Fourteen very-low-birth-weight (VLBW) preterm infants with and without intracranial hemorrhage (ICH) were prospectively followed from birth to 4 to 8 years for the purpose of determining neurologic and cognitive sequelae associated with ICH severity and to correlate outcomes with brain morphology as determined by Magnetic Resonance Imaging (MRI). Intracranial hemorrhage was documented by cranial ultrasonography performed in early life. Follow-up assessments included neurologic and psychometric examinations and cranial MRI scans. Of six children with no ICH, five had normal results on all three follow-up measures. Three children with Grade I-II ICH had mild to moderate neurologic and cognitive sequelae with focal white matter MRI abnormalities. Five children with Grade III-IV ICH had severe neurologic, cognitive, and MRI deficits, including MRI regional and diffuse white matter abnormalities and/or cortical atrophy. Focal and diffuse neurologic deficits correlated with the extent of MRI morphologic abnormalities. Results of this study indicate that ICH severity correlated with outcomes in children at follow-up; the more severe the ICH, the more adverse the neurologic, cognitive, and MRI results. MRI white matter abnormalities were present in all children with any degree ICH, while ventriculomegaly was seen only in severe ICH (Grade III-IV ICH). Neurologic deficits correlated with MRI structural abnormalities.

Brain↗
PubMed1996

A positron emission tomography study of primary orthostatic tremor.

Primary orthostatic tremor (OT), a clinical syndrome in which a rapid (14 to 16 Hz), regular lower limb tremor causes unsteadiness on standing, may be associated with a postural upper limb tremor of similar frequency. We used H2 15O PET to analyze the abnormal pattern of cerebral activation associated with the postural upper limb tremor in four patients with primary OT. Patients had regional cerebral bloodflow (rCBF) measured during involuntary tremor while maintaining a posture with their outstretched right upper limb and again at rest. Tremor was associated with abnormal bilateral cerebellar and contralateral lentiform and thalamic activation. These findings were evident on group analysis of pooled PET data after transformation into standard stereotactic space and in single subjects when PET images were coregistered with structural MRI of the brain. At rest, cerebellar blood flow was significantly increased bilaterally in OT when compared with age- and sex-matched controls. We have previously demonstrated similar abnormal bilateral cerebellar activation in essential and writing tremors and conclude that abnormal bilateral overactivity of cerebellar connections is a common feature of tremulous disorders.

Aged↗
PubMed1997

Autosomal dominant progressive syndrome of motor-speech loss without dementia.

This patient report describes a 68-year-old man with progressive dissolution in motor-speech without concomitant language or cognitive decline, with presumed autosomal dominant inheritance. Motor-speech impairments included marked difficulty in articulating words and in coordinating articulation, phonation, and respiration. Brain imaging results revealed severe focal atrophy of the posterior frontal region extending to the anterior parietal and superior temporal regions bilaterally on structural (MRI) and functional (single photon emission computed tomography) brain imaging studies. The involved neural substrate represented the primary motor cortex, premotor cortex (supplementary motor area), and the postcentral gyrus. Familial history included similar difficulties in his mother, her sister, and his own sister. The isolated involvement of the motor-speech processes alone indicated that this syndrome was distinguishable from progressive aphasia associated with prominent loss of language and from Alzheimer's disease.

Aged↗
PubMed2001

Frontotemporal dementia (Pick's disease): clinical features and assessment.

The clinical presentation in frontotemporal dementia (FTD) reflects the distribution of the pathologic changes rather than the exact histologic subtype of the disease. Three major clinical syndromes can be identified: 1) frontal variant FTD (dementia of frontal type) in which changes in social behavior and personality predominate, reflecting the orbitobasal frontal lobe focus of the pathology. Traditional cognitive tests are insensitive, but more specific measures are under development; 2) semantic dementia (progressive fluent aphasia) in which there is a breakdown in the conceptual database which underlies language production and comprehension, although deficits in nonverbal semantic knowledge can also be shown on neuropsychologic testing. Patients with semantic dementia have asymmetric anterolateral temporal atrophy with relative sparing of the hippocampal formation, which is typically worse on the left side. A variant of this syndrome affecting the right temporal lobe presents with progressive prosopagnosia; 3) progressive nonfluent aphasia in which the phonologic and syntactic components of language are affected in association with left peri-Sylvian atrophy. The assessment of patients with potential FTD involves a multidisciplinary approach. The development of comprehensive caregiver-based neuropsychiatric instruments, neuropsychologic tasks sensitive to semantic memory and other key cognitive impairments, and functional (hexamethyly-propyleneamine-SPECT) and structural (MRI) brain imaging represent significant advances in the field.

Aphasia, Primary Progressive↗
PubMed2002

Early detection and longitudinal changes in amyotrophic lateral sclerosis by (1)H MRSI.

OBJECTIVE: To determine 1) the reproducibility of metabolite measurements by (1)H MRS in the motor cortex; 2) the extent to which (1)H MRS imaging (MRSI) detects abnormal concentrations of N-acetylaspartate (NAA)-, choline (Cho)-, and creatine (Cre)-containing compounds in early stages of ALS; and 3) the metabolite changes over time in ALS. METHODS: Sixteen patients with definite or probable ALS, 12 with possible or suspected ALS, and 12 healthy controls underwent structural MRI and multislice (1)H MRSI. (1)H MRSI data were coregistered with tissue-segmented MRI data to obtain concentrations of NAA, Cre, and Cho in the left and right motor cortex and in gray matter and white matter of nonmotor regions in the brain. RESULTS: The interclass correlation coefficient of NAA was 0.53 in the motor cortex tissue and 0.83 in nonmotor cortex tissue. When cross-sectional data for patients were compared with those for controls, the NAA/(Cre + Cho) ratio in the motor cortex region was significantly reduced, primarily due to increases in Cre and Cho and a decrease in NAA concentrations. A similar, although not significant, trend of increased Cho and Cre and reduced NAA levels was also observed for patients with possible or suspected ALS. Furthermore, in longitudinal studies, decreases in NAA, Cre, and Cho concentrations were detected in motor cortex but not in nonmotor regions in ALS. CONCLUSION: Metabolite changes measured by (1)H MRSI may provide a surrogate marker of ALS that can aid detection of early disease and monitor progression and treatment response.

Amyotrophic Lateral Sclerosis↗
PubMed2002

Structural and functional neuroimaging in Alzheimer's disease: an update.

The field of neuroimaging has made several recent advances understanding Alzheimer's disease, a debilitating disease which affects approximately 4 million people in the United States [1]. Despite recent therapeutic advances, available treatments at present are aimed primarily at slowing progression of the disease rather than halting it completely or reversing its progression. Early detection of the disease has, therefore, been a major focus of a variety of neuroimaging techniques, including Positron Emission Tomography (PET), functional Magnetic Resonance Imaging (fMRI), and structural MRI. Recently, these techniques have also been found to be useful in monitoring cognitive and pathological progression of the disease, as well as monitoring response to clinical intervention treatment. A methodology review will be included here as well as a critical evaluation of the advantages and disadvantages of the various techniques.

Alzheimer Disease↗
PubMed2000

Cortical areas differentially involved in multiplication and subtraction: a functional magnetic resonance imaging study and correlation with a case of selective acalculia.

A patient with an intracranial hemorrhage showed differential impairment among arithmetic types (impaired in multiplication but not in subtraction). A functional magnetic resonance imaging (fMRI) experiment using normal volunteers also revealed a differential activation between the two arithmetic types. The fMRI result could account for the selective acalculia of the patient in that the lesion shown by structural MRI included the region with multiplication-higher activation and spared subtraction-higher regions. These findings suggest that the cognitive mechanism and neural substrates differ among the simple arithmetic operations.

Adult↗
PubMed1988

Neck pain.

Six conditions cause most of the neck pain complaints seen by primary care physicians: cervical muscle strain or sprain, torticollis, acceleration injury, myofascial pain dysfunction syndrome, and cervical osteoarthritis or rheumatoid arthritis. Most of them can be diagnosed and treated by the primary care physician. Of the more unusual causes, one should not miss a clinical fracture; a herniated cervical disc, spinal cord compression from a disc, or epidural tumor; infection of the disc or the vertebral body; subluxation of the vertebral bodies; or pain referred from the chest or mediastinal structures. MRI offers new opportunity for early diagnosis of myelopathy owing to OA or RA, vertebral osteomyelitis, and metastatic involvement of cervical vertebrae.

Humans↗
PubMedDate not supplied

[Neuropsychological consequences of perinatal asphyxia].

Perinatal asphyxia has been classically related to important neurological diseases such as cerebral palsy, but it it also stated that a high percentage of child with a good outcome did not show any sequelae. We reviewed cerebral lesions demonstrated by post-mortem analysis and the structural MRI contributions to the anatomo-functional correlates. The most frequent neuropsychological disturbances showed by these patients in the general intelligence, perceptive functions, memory and emotional and social behavior were also summarized.

Asphyxia Neonatorum↗
PubMed1998

[Progressive aphasia without dementia].

INTRODUCTION: Slowly progressive aphasia without generalized dementia is considered as a degenerative disorder that can be differentiated of others well-known neurodegenerative disorders. CLINICAL CASE: We present a case report of a patient with slowly progressive aphasia, characterized by a progressive anomia and without generalized dementia. The patient was evaluated in the last four years: a neuropsychological assessment, a neurological exploration and structural (MRI) and functional (SPECT) neuroimaging were performed. CONCLUSION: This case is interesting on account of a selective implication of the left temporal hemisphere is showed in the pathogenesis of this disorder.

Anomia↗
PubMed1995

Use of MRI for measuring structures in frozen postmortem brain.

A method was developed for magnetic resonance imaging (MRI) of human autopsy brains stored long-term at -70 degrees C. Scanning brains at temperatures between -70 and -8 degrees C gave minimal MRI signals consistent with protons having limited freedom of movement at low temperature. Raising brain temperature improved the signal such that scanning at -1 degree C generated images with good in-plane resolution, grey/white matter contrast, and fine detail of cortical sulcal/gyral patterns. To validate the method, volume and area measurements were made using computerized image analysis on stored digital images of 14 brains from adult subjects of both genders and various ages. The data confirmed that brain volume was inversely correlated with age, and female subjects had smaller brains. This is a valuable new method for acquiring morphometric data from previously unscanned pathologic brains that are to be used for neurochemical and molecular investigations.

Analysis of Variance↗
PubMed1999

MRI anatomy of schizophrenia.

Structural magnetic resonance imaging (MRI) data have provided much evidence in support of our current view that schizophrenia is a brain disorder with altered brain structure, and consequently involving more than a simple disturbance in neurotransmission. This review surveys 118 peer-reviewed studies with control group from 1987 to May 1998. Most studies (81%) do not find abnormalities of whole brain/intracranial contents, while lateral ventricle enlargement is reported in 77%, and third ventricle enlargement in 67%. The temporal lobe was the brain parenchymal region with the most consistently documented abnormalities. Volume decreases were found in 62% of 37 studies of whole temporal lobe, and in 81% of 16 studies of the superior temporal gyrus (and in 100% with gray matter separately evaluated). Fully 77% of the 30 studies of the medial temporal lobe reported volume reduction in one or more of its constituent structures (hippocampus, amygdala, parahippocampal gyrus). Despite evidence for frontal lobe functional abnormalities, structural MRI investigations less consistently found abnormalities, with 55% describing volume reduction. It may be that frontal lobe volume changes are small, and near the threshold for MRI detection. The parietal and occipital lobes were much less studied; about half of the studies showed positive findings. Most studies of cortical gray matter (86%) found volume reductions were not diffuse, but more pronounced in certain areas. About two thirds of the studies of subcortical structures of thalamus, corpus callosum and basal ganglia (which tend to increase volume with typical neuroleptics), show positive findings, as do almost all (91%) studies of cavum septi pellucidi (CSP). Most data were consistent with a developmental model, but growing evidence was compatible also with progressive, neurodegenerative features, suggesting a "two-hit" model of schizophrenia, for which a cellular hypothesis is discussed. The relationship of clinical symptoms to MRI findings is reviewed, as is the growing evidence suggesting structural abnormalities differ in affective (bipolar) psychosis and schizophrenia.

Brain↗
PubMedDate not supplied

Assessment of posterior fossa structures with midsagittal MRI: the effects of age.

Midsagittal magnetic resonance (MR) images of 36 normal volunteers, ranging in age from 26 to 79 years, were used to evaluate the effects of age on the size of posterior fossa structures (cerebellar vermis, midbrain, pons, medulla and fourth ventricle). Our results demonstrate a highly statistically significant age-related decline in the cross-sectional area of the midbrain (r = -.44, p less than 0.007), a less prominent decline in the area of the anterior cerebellar vermis (r = -.33, p less than 0.05) and striking intercorrelations between the dimensions of the pons, medulla and cerebellar vermis. To the best of our knowledge, this is the first MRI demonstration of midbrain atrophy during aging in normal adults.

Adult↗
PubMed2001

Unfolding the human hippocampus with high resolution structural and functional MRI.

The hippocampus is a region of the brain that is crucial to memory function. Functional neuroimaging allows for the noninvasive investigation of the neurophysiology of human memory by observing changes in blood flow in the brain. We have developed a technique that employs high-resolution functional magnetic resonance imaging (fMRI) in combination with cortical unfolding to provide activation maps of the hippocampal region that surpass in anatomic and functional detail other methods of in vivo human brain mapping of the medial temporal lobe. We explain the principles behind this method and illustrate its application to a novelty-encoding paradigm.

Brain Mapping↗
PubMed2001

Does the trabecular bone structure depicted by high-resolution MRI of the calcaneus reflect the true bone structure?

RATIONALE AND OBJECTIVES: The purpose of this study was to compare trabecular bone structure parameters assessed with high-resolution magnetic resonance imaging (HR-MRI) with those determined in specimen sections. METHODS: High-resolution MR images were obtained for 30 calcaneus specimens with a three-dimensional, T1-weighted spin-echo sequence (spatial in-plane resolution 0.195 mm, slice thicknesses of 0.3 and 0.9 mm). Thirty-eight sections were obtained from the specimens, and contact radiography was performed. In the corresponding sections, structural parameters analogous to bone histomorphometry were determined. RESULTS: Significant correlations between MRI-derived structural parameters and those derived from macro pathological sections were found: r values of up to 0.75 were obtained (P < 0.01). The highest correlations were found for apparent bone volume/total volume and trabecular thickness. Image thresholding techniques showed a significant impact on these correlations (P < 0.01). The thinner MR sections were less susceptible to the different thresholding algorithms. CONCLUSIONS: Trabecular bone structure depicted by HR-MR images is significantly correlated with that shown in macro sections (P < 0.01); however, a number of limitations have to be considered, including the substantial impact of thresholding techniques and slice thickness.

Aged↗