RESUMO
To confirm the previous reports demonstrating the difference in the octanol extraction fractions between the currently available two N-isopropyl-4-iodoamphetamine (123I) products (IMP(A) and IMP(B)), we newly developed the standard input function for IMP(B) in 19 healthy volunteers and compared it with the established standard input function, which has been originally generated with IMP(A). The octanol extraction fractions of IMP(B) were stable from 5 minutes to 16 minutes post injection and significantly higher than those of IMP(A). The mCBFs calculated with IMP(B) by using the established standard input function for IMP(A) tended to be higher than those with the combination of IMP(A) and the established standard input function though the difference was not significant. When measured with IMP(B) combined with the correspondent standard input function, mCBFs were identical to those calculated with IMP(A) with the established standard input function, suggesting that the appropriate standard input function should be used according to the product used.
Assuntos
Radioisótopos do Iodo/normas , Iofetamina/normas , Compostos Radiofarmacêuticos/normas , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
We evaluated the relationship between regional cerebral blood flow (rCBF) and clinical symptoms in patients with schizophrenia. Single photon emission computed tomography with N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) was used to study 29 patients with schizophrenia. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). We examined the correlation between rCBF and each BPRS item score using Statistical Parametric Mapping software. Corrected P-values < 0.05 were considered as statistically significant. The suspiciousness score on the BPRS was positively correlated with rCBF in the left inferior temporal gyrus. There was no significant correlation between rCBF and any other items of the BPRS. There was no significant correlation between rCBF and chlorpromazine-equivalent dosage. This analysis permits the quantitative assessment of the severity of persecutory delusions in relation to left temporal perfusion in patients with schizophrenia.
Assuntos
Escalas de Graduação Psiquiátrica Breve , Lateralidade Funcional/fisiologia , Transtornos da Personalidade/diagnóstico , Esquizofrenia/diagnóstico , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Lobo Temporal/irrigação sanguínea , Lobo Temporal/fisiopatologia , Adolescente , Adulto , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos da Personalidade/etiologia , Esquizofrenia/complicações , Índice de Gravidade de Doença , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Lithium is clinically available for the treatment of mood disorders. However, it has remained unclear how lithium acts on the brain to produce its effects. The aim of this study was to evaluate the effects of chronic lithium on human brain activity using positron emission tomography and clarify the correlation between brain activity changes and cognitive functional changes as induced by chronic lithium administration. A total of 20 healthy male subjects (mean age, 32 +/- 6 years) underwent positron emission tomographic scans with F-fluorodeoxyglucose and a battery of neuropsychological tests at baseline condition and after 4 weeks of lithium administration. Brain metabolic data were analyzed using statistical parametric mapping. Lithium increased relative regional cerebral glucose metabolism (rCMRglc) in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased rCMRglc in the right cerebellum and left lingual gyrus/cuneus. There was no difference in any of the variables of cognitive functions between the baseline condition and after chronic lithium administration. There was no correlation between rCMRglc changes in any of the brain regions and individual variable changes in any of the neuropsychological tests. The results suggest that the effects of chronic lithium are associated with increased activity in the bilateral dorsomedial frontal cortices including the anterior cingulate gyrus and decreased activity in the right cerebellum and left lingual gyrus/cuneus.
Assuntos
Encéfalo/efeitos dos fármacos , Glucose/metabolismo , Carbonato de Lítio/farmacologia , Adulto , Antimaníacos/administração & dosagem , Antimaníacos/farmacocinética , Antimaníacos/farmacologia , Encéfalo/metabolismo , Relação Dose-Resposta a Droga , Fluordesoxiglucose F18 , Lobo Frontal/efeitos dos fármacos , Lobo Frontal/metabolismo , Giro do Cíngulo/efeitos dos fármacos , Giro do Cíngulo/metabolismo , Humanos , Processamento de Imagem Assistida por Computador , Carbonato de Lítio/sangue , Carbonato de Lítio/farmacocinética , Masculino , Testes Neuropsicológicos , Tomografia por Emissão de Pósitrons/métodos , Compostos RadiofarmacêuticosRESUMO
PURPOSE: Traumatic brain injury (TBI) causes brain dysfunction in many patients. However, some patients have severe brain dysfunction but display no abnormalities on magnetic resonance imaging (MRI). There have been some reports of hypometabolism even in such patients. The purpose of this study was to investigate the relationship between metabolic abnormality and loss of neuronal integrity in TBI patients with some symptoms but without MRI abnormalities. METHODS: The study population comprised ten patients with TBI and ten normal volunteers. All of the patients were examined at least 1 year after the injury. ( 15)O-labelled gas PET and [(11)C]flumazenil (FMZ) positron emission tomography (PET) were carried out. The cerebral metabolic rate of oxygen (CMRO(2)) and binding potential (BP) images of FMZ were calculated. Axial T2WI, T2*WI and FLAIR images were obtained. Coronal images were added in some cases. RESULTS: All of the patients had normal MRI findings, and all showed areas with abnormally low CMRO(2). Low uptake on BP images was observed in six patients (60%). No lesions that showed low uptake on BP images were without low CMRO(2). On the other hand, there were 14 lesions with low CMRO(2) but without BP abnormalities. CONCLUSION: These results indicate that there are metabolic abnormalities in TBI patients with some symptoms after brain injury but without abnormalities on MRI. Some of the hypometabolic lesions showed low BP, indicating a loss of neuronal integrity. Thus, FMZ PET may have potential to distinguish hypometabolism caused by neuronal loss from that caused by other factors.