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1.
Arch Gen Psychiatry ; 49(7): 553-7, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1627046

RESUMO

A role of the caudate nucleus in depression has been suggested from relevant clinical conditions, such as patients with Huntington's disease or caudate infarcts, as well as animal studies. Correlations of caudate nucleus disease with depressive symptoms have been limited to autopsy studies and cases of gross pathological disorder, such as large infarcts. We used serial axial high-field magnetic resonance images and an unbiased stereological technique to estimate the volumes of the caudate nuclei in 50 patients who met DSM-III criteria for major depression (23 men, 48.3 +/- 17 years old) in comparison with 50 age- and gender-matched normal controls free of major neurological and psychiatric disorders. Depressed patients had smaller caudate nucleus volumes (5.2 +/- 1.6 cm3) compared with controls (6.2 +/- 1.7 cm3). Right and left caudate nucleus volumes were smaller in depressed patients compared with controls. Age was negatively correlated with caudate nucleus volumes in depressed patients as well as in controls. Caudate nucleus volumes in depressed patients were inversely correlated with the bicaudate and bifrontal indices. These results may be the first demonstration of diminished caudate nucleus volumes in depression and suggest a role for the caudate nucleus in the pathogenesis of major depression.


Assuntos
Núcleo Caudado/anatomia & histologia , Transtorno Depressivo/diagnóstico , Imageamento por Ressonância Magnética , Fatores Etários , Análise de Variância , Encéfalo/anatomia & histologia , Núcleo Caudado/fisiopatologia , Transtorno Depressivo/etiologia , Transtorno Depressivo/fisiopatologia , Feminino , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade
2.
J Clin Endocrinol Metab ; 72(2): 256-9, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1991797

RESUMO

Magnetic resonance images centered at the pituitary stalk were used to measure pituitary gland size in 19 patients with major depression compared with that in age- and sex-matched controls. Depressed patients had significantly greater pituitary cross-sectional area (P = 0.0009) and volume (P = 0.007) than the controls. This difference was particularly prominent in elderly depressed patients compared to elderly controls. These results provide the first demonstration of structural alterations in the pituitary gland in major depression.


Assuntos
Transtorno Depressivo/patologia , Hipófise/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade
3.
J Clin Endocrinol Metab ; 71(2): 505-8, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2380345

RESUMO

We used sagittal and coronal T1 weighted magnetic resonance images, at 1.5 Tesla, to measure the height, width, length, and cross-sectional area and to generate two estimates of pituitary gland volume in 35 normal volunteers aged 26-79 yr (19 females and 16 males). Subjects over 50 yr of age had significantly smaller pituitary gland height (P = 0.03), area (P = 0.04), and volume (P = 0.04) than those under 50 yr (by two-tailed t test). Overall, age was negatively correlated with pituitary volume (V1: r = -0.51; P = 0.003; V2: r = -0.47; P = 0.008), area (r = -0.43; P = 0.009), and height (r = -0.46; P = 0.005), but not with pituitary length or width. There were no statistically significant differences in pituitary size between men and women (by two-tailed t test). These findings suggest that pituitary gland height provides a good single measure for the assessment of pituitary gland size and that age must be controlled for in studies of pituitary gland size.


Assuntos
Hipófise/crescimento & desenvolvimento , Adulto , Idoso , Envelhecimento , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Hipófise/anatomia & histologia , Valores de Referência , Fatores Sexuais
4.
Biol Psychiatry ; 28(3): 266-74, 1990 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-2378929

RESUMO

We examined magnetic resonance (MR) scans of the heads of 8 patients with late onset psychosis and 8 aged controls. Although some patients had mild cognitive impairment, none had depression or a history or examination suggesting focal brain disease. Thus, all patients met DSM-III-R criteria for late-onset schizophrenia. All 8 patients showed significant leukoencephalopathy or vascular pathology on MR imaging, and temporoparietal and occipital lesions were especially prominent. Little such pathology was evident on control scans. We suggest that focal brain disease of vascular origin may be associated with late-onset psychosis, and that MR scanning of such cases may provide important clues to pathogenesis.


Assuntos
Encéfalo/patologia , Demência/diagnóstico , Imageamento por Ressonância Magnética , Transtornos Neurocognitivos/diagnóstico , Esquizofrenia Paranoide/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Delusões/diagnóstico , Diagnóstico Diferencial , Feminino , Alucinações/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
5.
Biol Psychiatry ; 29(7): 665-70, 1991 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-1647227

RESUMO

We examined the relationship between platelet [3H]-imipramine binding and leukoencephalopathy as assessed by 1.5 Tesla Magnetic Resonance Imaging (MRI) in 21 elderly depressed patients who satisfied DSM-III criteria for major depression. Both drug-free platelet [3H]-imipramine binding and brain MRI studies were obtained during the same episode of depression. Our findings show a significant inverse relationship between frequency of subcortical hyperintensity (SCH) and the number (Bmax) of platelet [3H]-imipramine binding sites. Patients with Bmax less than 850 fmol/mg protein had significantly larger SCH compared with patients with a higher Bmax. These data provide further support to the potential use of platelet [3H]-imipramine binding studies and brain MR imaging as diagnostic adjuncts in geriatric depression and suggest, moreover, that these two biological markers may be linked in geriatric patients with depression.


Assuntos
Plaquetas/metabolismo , Proteínas de Transporte , Demência/diagnóstico , Transtorno Depressivo/diagnóstico , Imipramina/farmacocinética , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Imageamento por Ressonância Magnética , Receptores de Droga , Receptores de Neurotransmissores/metabolismo , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Demência/sangue , Transtorno Depressivo/sangue , Feminino , Humanos , Leucoencefalopatia Multifocal Progressiva/sangue , Masculino , Pessoa de Meia-Idade
6.
Biol Psychiatry ; 29(8): 799-810, 1991 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-2054453

RESUMO

The magnetic resonance scans of 22 patients with early-onset Alzheimer's disease (AD) were compared to 16 age-matched neurologically normal controls for the presence of white matter subcortical hyperintensities (SCH) and periventricular hyperintensities (PVH). Patients with AD were significantly more likely to have evidence of PVH (p less than 0.01) than age-matched controls. There was no significant difference between the two groups in either the frequency of SCH or the size of the largest lesion. Within the AD group, there was no difference demonstrated in the location of the SCH, either in the anterior-posterior plane or between the two hemispheres. Patients with AD more frequently demonstrated ventriculomegaly (p less than 0.001) and sulcal widening (p less than 0.05) compared with controls. This study suggests that the SCH seen in early-onset AD patients on MRI are related more to the aging process than to the AD process and that the increased frequency of PVH may have a relationship to the disease process.


Assuntos
Doença de Alzheimer/diagnóstico , Encéfalo/patologia , Imageamento por Ressonância Magnética , Idoso , Doença de Alzheimer/psicologia , Córtex Cerebral/patologia , Ventrículos Cerebrais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
7.
Biol Psychiatry ; 28(2): 110-6, 1990 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-2378917

RESUMO

Magnetic resonance imaging (MRI) of the brain was used to examine the morphology and dimensions of the pituitary gland in 18 patients with eating disorders (8 anorectics and 10 bulimics), in comparison with 13 healthy volunteers. None of the 18 patients with anorexia or bulimia had any radiological evidence suggestive of pituitary macroadenoma, cyst, or empty sella. Measurements revealed that the anorectics and bulimics had smaller pituitary gland cross-sectional areas (p less than 0.05) and smaller pituitary gland heights, compared with healthy controls. These preliminary findings in anorectics and bulimics are suggestive of pituitary atrophy secondary to nutritional or endocrine alterations, rather than a primary pituitary pathology.


Assuntos
Anorexia Nervosa/diagnóstico , Bulimia/diagnóstico , Imageamento por Ressonância Magnética , Hipófise/patologia , Adolescente , Adulto , Feminino , Humanos , Tamanho do Órgão/fisiologia , Neuro-Hipófise/patologia
8.
Neurobiol Aging ; 12(3): 245-7, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1876230

RESUMO

Subcortical structural changes have been reported to occur in some elderly subjects with late age onset depression. Given the association between diseases affecting subcortical structures and affective disorders, this suggests that these structural changes may be involved in the etiology of late age onset depression in some patients. With the advent of Brain Magnetic Resonance Imaging (MRI), "in vivo" analysis of these subcortical structures is now possible. The authors report a higher occurrence of caudate (60% vs. 11%) and large deep white matter hyperintensities (60% vs. 11%) in late age onset elderly depressed subjects compared with early onset elderly depressed subjects. These results suggest that late age onset depression may be mediated by caudate and white matter structural changes in some patients.


Assuntos
Envelhecimento/fisiologia , Encéfalo/patologia , Depressão/patologia , Idoso , Gânglios da Base/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
9.
Neurobiol Aging ; 12(4): 371-4, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1961373

RESUMO

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.


Assuntos
Envelhecimento/fisiologia , Fossa Craniana Posterior/anatomia & histologia , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fatores Sexuais
10.
Neurology ; 44(9): 1721-7, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7936304

RESUMO

The activity of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in the treatment of primary central nervous system lymphoma (PCNSL) prior to radiotherapy was studied in six patients. Primary lesions were reduced by 80% or more on contrast-enhancing cross-sectional area in four patients and to a lesser extent in two others after two cycles of chemotherapy. The primary lesion sites demonstrated no contrast enhancement in the three patients who completed four cycles of therapy. However, concurrent with response at the primary disease sites, multiple lesions occurred at distant, noncontiguous CNS parenchymal sites in five patients after two to four cycles of chemotherapy. Median survival was 8.5 months for the six enrolled patients and 16.5 months for the four patients completing craniospinal radiotherapy. PCNSL is highly responsive to standard systemic non-Hodgkin's lymphoma chemotherapy regimens, but the pattern and rapidity of relapse suggest mechanisms of failure including inherent or rapidly evolving antineoplastic drug resistance and perhaps limited drug delivery to occult sites of disease in the brain.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Linfoma/tratamento farmacológico , Idoso , Neoplasias do Sistema Nervoso Central/diagnóstico por imagem , Neoplasias do Sistema Nervoso Central/radioterapia , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Humanos , Linfoma/diagnóstico por imagem , Linfoma/radioterapia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/radioterapia , Prednisona/uso terapêutico , Radiografia , Vincristina/uso terapêutico
11.
Neuroreport ; 11(3): 609-15, 2000 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-10718323

RESUMO

Neural circuits in the cerebellum are essential for eyeblink classical conditioning, and hippocampal activation is also present during acquisition. Anatomical (volumetric) brain MRI, delay eyeblink conditioning and neuropsychological tests were administered to eight healthy older subjects. The correlation between cerebellar volume (corrected for total cerebral volume) and conditioned response percentage was 0.81 (p < 0.02), but neither hippocampal nor total cerebral volume correlated with conditioning or any neuropsychological test scores. There was no relationship between age and cerebellar volume, but the correlation between hippocampal volume and age was -0.80 (p < 0.02). These volumetric results add to the increasing evidence in humans demonstrating a relationship between the integrity of the cerebellum and eyeblink classical conditioning.


Assuntos
Cerebelo/anatomia & histologia , Condicionamento Clássico/fisiologia , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Piscadela/fisiologia , Encéfalo/anatomia & histologia , Feminino , Hipocampo/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Valores de Referência
12.
Artigo em Inglês | MEDLINE | ID: mdl-7846284

RESUMO

1. Seven subjects with depression and matched controls were studied using proton spectroscopy to test the hypothesis that choline will be elevated in depression. 2. The proton spectroscopy was repeated after recovery from depression. 3. The study confirmed a state dependent increase in choline in the brain. 4. This change may be used as an in vivo marker of change in depression.


Assuntos
Antidepressivos/uso terapêutico , Química Encefálica/fisiologia , Colina/metabolismo , Transtorno Depressivo/metabolismo , Idoso , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Química Encefálica/efeitos dos fármacos , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/psicologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
13.
Prog Neuropsychopharmacol Biol Psychiatry ; 18(6): 995-1004, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7824764

RESUMO

1. The present study was done to assess the brain metabolites measured by proton magnetic resonance spectroscopy (MRS) in normal individuals. 2. Proton spectroscopy STEAM voxel technique with chemical shift imaging was used to provide localized metabolic information from the brains of 34 normal volunteers (15 males) between the ages of 21 and 75 years. 3. Choline, Creatine and N-acetyl aspartate (NAA) was lower in white matter than gray matter. Choline/NAA and choline/creatine ratios were also lower in white matter. The choline, creatine and NAA were lower in older subjects in the voxel representing cortical and subcortical gray matter. There were no differences between males and females. 4. This preliminary study suggests that age matching is essential for comparative studies of disease states using proton MRS.


Assuntos
Envelhecimento/metabolismo , Química Encefálica/fisiologia , Encéfalo/anatomia & histologia , Adulto , Idoso , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encéfalo/fisiologia , Colina/metabolismo , Creatina/metabolismo , Feminino , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Caracteres Sexuais
14.
Artigo em Inglês | MEDLINE | ID: mdl-1862218

RESUMO

1. The frequent occurrence of hypothalamo-pituitary dysfunction in patients with eating disorders as well as prior reports that nutritional and endocrine status influence pituitary morphology, led us to hypothesize that pituitary size and shape may be altered in patients with eating disorders. 2. Magnetic resonance imaging (MRI) does not use ionizing radiation and is currently one of the most feasible modalities available to study the pituitary gland in vivo. Using MRI, we have previously reported in a preliminary study that female patients with eating disorders had significantly smaller pituitary glands than controls. In addition MRI excluded any pituitary mass lesions. 3. In this report, we confirm our previous MRI findings and provide further evidence of pituitary abnormalities in an expanded sample of eating disorder patients. Preliminary data on pituitary volume estimates from MRI scans are provided for a subset of patients and controls.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos/patologia , Hipófise/anormalidades , Adolescente , Adulto , Anorexia/patologia , Bulimia/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Quiasma Óptico/patologia , Hipófise/patologia
15.
AJNR Am J Neuroradiol ; 13(5): 1439-45, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1414839

RESUMO

PURPOSE: To further elucidate the nonparamagnetic effects of T1-relaxation mechanisms in MR imaging. PATIENTS AND METHODS: In 12 patients with lesions having hyperintense signal on T1-weighted spin-echo MR, findings were correlated with autopsy/surgical biopsy in seven cases and/or noncontrast CT scans in 10 cases. RESULTS: Eight of the 10 CT scans demonstrated hyperattenuation in the lesions, indicating mineralization, which correlated with the areas of hyperintense signal on MR. Histologic characterization of the mineralization was accomplished in three cases using four stains; hematoxylineosin, alizarin red S, von Kassa stains for calcium and Perls' iron. The areas of mineralization were homogeneously strongly positive with the calcium stains and only focally weakly positive with the Perls' iron stain. The mineralization was further characterized in all three cases as containing calcium and phosphorus using energy-dispersive x-ray analysis. Four of the 12 cases had either no correlating CT scans (two cases) or the CT showed no hyperattenuating properties to the lesions (two cases). In all four of these cases, microscopic examination showed that the gyriform configuration of the cortical hyperintense signal on T1-weighted images correlated with linear zones of nonhemorrhagic laminar necrosis (cerebral infarction). No mineralization, except for an occasional ferruginated neuron, could be demonstrated with the four histologic stains. Specimen MR imaging of formalin-fixed brain sections in one case demonstrated in vitro the gyriform hyperintense signal seen in vivo. CONCLUSION: Our studies describe and pathologically characterize two associations with T1 shortening in neuroimaging unrelated to the presence of heme: 1) calcification and 2) laminar necrosis in cerebral infarction.


Assuntos
Encefalopatias/diagnóstico , Encéfalo/patologia , Calcinose/diagnóstico , Infarto Cerebral/diagnóstico , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X , Encéfalo/diagnóstico por imagem , Encefalopatias/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Humanos
16.
AJNR Am J Neuroradiol ; 10(2): 293-302, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2494848

RESUMO

We examined the MR appearance of the hindbrain deformity, including the upper cervical spinal canal and craniovertebral junction, in 33 patients with Chiari II malformation. In this disorder, there is impaction at birth of the medulla and cerebellar vermis into the upper cervical spine, resulting in obliteration of the subarachnoid space and scalloping of the dens. Spinal canal enlargement during the child's growth, combined with dorsal displacement of neural tissue, eventually causes marked widening of the precervical subarachnoid space. This enlargement may simulate an intradural mass. Our series documents the changes seen at birth and the progression of the widened precervical space through the first and second decades. Twelve (36%) of the 33 patients studied were symptomatic, with brainstem or longtract symptomatology, and 11 of these required surgery. This group was compared with the remaining 21 asymptomatic Chiari II patients to identify MR features associated with clinical deterioration. The level of descent of the hindbrain hernia was critical; eight of 12 symptomatic patients had a cervicomedullary kink at C4 or lower, while no asymptomatic patients had a fourth ventricle, medulla, or kink below C3-C4. The precervical cord subarachnoid space was slightly wider in asymptomatic patients, although there was great overlap. In five patients with follow-up scans, this space was seen to increase in width after laminectomy. A CSF flow void was present in the precervical space in about 25% of patients in both groups. In nine of 12 symptomatic patients, C1 arch indentation of the dura (causing significant compression) was confirmed surgically. However, seven (33%) of the 21 asymptomatic patients also had this appearance. Absolute measurement of the anteroposterior diameter of the canal at C1 ranged from 11 to 25 mm in both groups. Retrocollis, which persisted despite sedation for MR, was seen in two patients, both symptomatic. Recognition of the vermis, medullary kink, cervical cord, C1 arch, fourth ventricle, and precervical space in Chiari II patients is fundamental to the analysis of symptoms in


Assuntos
Malformação de Arnold-Chiari/diagnóstico , Tronco Encefálico/patologia , Encefalocele/diagnóstico , Imageamento por Ressonância Magnética , Meningomielocele/diagnóstico , Adolescente , Malformação de Arnold-Chiari/cirurgia , Vértebras Cervicais/patologia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Bulbo/patologia , Complicações Pós-Operatórias/diagnóstico , Medula Espinal/patologia , Espaço Subaracnóideo/patologia
17.
AJNR Am J Neuroradiol ; 12(2): 309-14, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1902033

RESUMO

The neuroimaging studies, clinical evaluations, and surgical and pathologic findings in five children with biopsy-proved hamartomas of the tuber cinereum were reviewed. Surgical and/or MR findings showed that patients with precocious puberty had pedunculated lesions while those with seizures had tumors that were sessile with respect to the hypothalamus. The radiologic studies included six MR examinations in four patients and CT studies in all five patients. Three children presented with precocious puberty and two with seizures, one of which was a gelastic (spasmodic or hysteric laughter) type of epilepsy. MR studies were obtained both before and after surgery in two patients, only preoperatively in a third patient, and only postoperatively in the fourth child. MR was superior to CT in displaying the exact size and anatomic location of the hamartomas in all cases. The mass was isointense with gray matter on sagittal and coronal T1-weighted images, which best displayed the relationship of the hamartoma to the third ventricle, infundibulum, and mammillary bodies. Intermediate- or T2-weighted images showed signal characteristics of the hamartoma to be isointense (one case) or hyperintense (two cases) relative to gray matter. The difference in T2 signal intensity did not correlate with any obvious differences in histopathology. CT showed attenuation isodense with gray matter, and no calcium. There was no enhancement on CT. There was no enhancement on MR in the one case in which contrast medium was administered. Preservation of the posterior pituitary bright spot was noted on all pre- and postoperative T1-weighted MR scans.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Hamartoma/patologia , Neoplasias Hipotalâmicas/patologia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Criança , Pré-Escolar , Feminino , Hamartoma/complicações , Hamartoma/epidemiologia , Humanos , Neoplasias Hipotalâmicas/complicações , Neoplasias Hipotalâmicas/epidemiologia , Masculino , Puberdade Precoce/epidemiologia , Puberdade Precoce/etiologia , Estudos Retrospectivos , Convulsões/epidemiologia , Convulsões/etiologia , Túber Cinéreo
18.
AJNR Am J Neuroradiol ; 9(6): 1061-8, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3143230

RESUMO

A prominent decreased signal intensity can be seen in many of the heavily myelinated, compact fiber pathways of the brain on T2-weighted spin-echo MR images (TR = 2500 msec, TE = 80 msec). These areas include the anterior commissure, internal capsule, optic tract and radiations, fornix, mammillothalamic tract, superior frontooccipital fasciculus, cingulum, corpus callosum, uncinate fasciculus, and superior longitudinal fasciculus. All these pathways could be identified in normal subjects 3 years old and older when 1.5-T axial and coronal images of 50 adults and 17 children were reviewed. Correlation of the in vivo and postmortem MR appearance of two human brains with Perls and Luxol fast blue stains indicates that the short T2 reflects heavy myelination and fiber density, not iron deposition. This is in contrast to the short T2 signal seen in the subcortical U fibers and deep nuclei of the brain that result from iron deposition. These pathways also differ from areas of brain iron accumulation in that (1) they may appear as areas of short T1 on partial-saturation or inversion-recovery pulse sequences and (2) they can be seen with regularity in all patients over 3 years of age. It is important to distinguish between the effect of the myelin sheath and the effect of brain iron on the T2 relaxation values seen in the normal brain since both result in shortened T2 relaxation. The importance of the role of these fiber tracts in disease processes and in modifying the spread of vasogenic edema and tumor needs further investigation.


Assuntos
Encéfalo/anatomia & histologia , Imageamento por Ressonância Magnética , Adolescente , Adulto , Idoso , Envelhecimento/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Hipotálamo/anatomia & histologia , Lactente , Pessoa de Meia-Idade , Bainha de Mielina/fisiologia , Vias Neurais/anatomia & histologia
19.
AJNR Am J Neuroradiol ; 14(5): 1043-8, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8237678

RESUMO

PURPOSE: To provide further quantitative studies concerning the relationship with age between regional brain iron and T2 shortening. METHODS: a) Quantitative T2 calculations of eight anatomic regions (red nucleus, substantia nigra, dentate nucleus, corpus callosum, caudate, putamen, temporal lobe white matter, and frontal lobe white matter) from T2-weighted spin-echo images were performed in 60 patients aged newborn to 35 years. b) Quantitative brain iron concentrations were obtained in six of the eight anatomic regions (red nucleus, substantia nigra, dentate nucleus, corpus callosum, cauda, and putamen) using 13 autopsied brains (newborn to 78 years). Brain tissue from these six regions was digested with 0.6 N HCl-2.5% wt/vol KMnO4 for 2 hours at 60 degrees C. After centrifugation, 0.1 mL of an iron-chelating reagent (2 mol/L ascorbic acid, 5 mol/L ammonium acetate, 6.5 nmol/L ferrozine, 13.1 mmol/L neocuprine) was added and the absorbance was measured at 562 nm/L and compared with a standard curve with ferric chloride. c) The in vivo iron concentrations in tissue that were obtained were reproduced in four test tube phantom studies with ferric ammonium sulfate or ferrous ammonium sulfate dissolved in either deionized water or 5% agarose. T2 calculations of the phantoms were made with a single-section multiple repetition time, multiple echo time acquisition. RESULTS: a) Clinical T2 calculations--all eight anatomic regions showed a decrease with age in T2 value, beginning shortly after birth. During the first three decades, the T2 shortening was most significant in the region of substantia nigra. b) Quantitative brain iron--five anatomic regions but not the corpus callosum demonstrated an age-related increase in brain iron (1449.6 nmol/g for the red nucleus versus 261.8 nmol/g for the corpus callosum). c) T2 effect of iron in vitro--both the ferric and ferrous iron phantoms showed a decreased T2 value in the in vivo concentration range of iron obtained from the postmortem studies. The T2 shortening was most marked for the ferric phantoms. CONCLUSION: There is an age-related accumulation of iron in five regions of the brain, correlating with an associated decrease in T2 value that can be demonstrated in iron phantoms. Brain iron appears to contribute to the progressive decrease of T2 signal that occurs with aging.


Assuntos
Química Encefálica , Ferro/análise , Imageamento por Ressonância Magnética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Núcleo Caudado/química , Núcleos Cerebelares/química , Córtex Cerebral/química , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Putamen/química , Núcleo Rubro/química , Substância Negra/química
20.
AJNR Am J Neuroradiol ; 11(2): 329-32, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2107715

RESUMO

Three children with known primary brain neoplasms and leptomeningeal disease were evaluated with MR imaging. Two of the patients had medulloblastoma and one had pineoblastoma. The presence of leptomeningeal tumor spread was established by positive CSF cytopathology in conjunction with compatible contrast-enhanced CT findings. Contrast-enhanced CT, nonenhanced MR, and Gd-DTPA-enhanced MR studies were then compared. In two cases, leptomeningeal lesions were seen better with Gd-DTPA-enhanced MR than with contrast-enhanced CT. In all three cases, Gd-DTPA MR imaging revealed lesions that were not identified on noncontrast MR. Gd-DTPA-enhanced MR imaging is useful when searching for intracranial leptomeningeal tumor deposits in pediatric patients at risk for this condition.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Meduloblastoma/secundário , Neoplasias Meníngeas/secundário , Compostos Organometálicos , Ácido Pentético , Pinealoma/secundário , Neoplasias Encefálicas/patologia , Neoplasias Cerebelares/patologia , Criança , Pré-Escolar , Feminino , Gadolínio , Gadolínio DTPA , Humanos , Masculino , Meduloblastoma/diagnóstico , Neoplasias Meníngeas/diagnóstico , Pinealoma/diagnóstico
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