972 resultados para Ultrafast MRI
Resumo:
Previous studies have suggested that bipolar disorder (BD) is associated with alterations in neuronal plasticity, but the effects of the progression of illness on brain anatomy have been poorly investigated. We studied the correlation between length of illness, age, age at onset, and the number of previous episodes and total brain, total gray, and total white matter volumes in BD, unipolar (UP) and healthy control (HC) subjects. Thirty-six BD, 31 UP and 55 HCs underwent a 1.5 T brain magnetic resonance imaging scan, and gray and white matter volumes were manually traced blinded to the subjects` diagnosis. Partial correlation analysis showed that length of illness was inversely correlated with total gray matter volume after adjusting for total intracranial volume in BD (r(p)=-0.51; p=0.003) but not in UP subjects (r(p)=-0.23; p=0.21). Age at illness onset and the number of previous episodes were not significantly correlated with gray matter volumes in BD or UP subjects. No significant correlation with total white matter volume was observed. These results suggest that the progression of illness may be associated with abnormal cellular plasticity. Prospective longitudinal studies are necessary to elucidate the long-term effects of illness progression on brain structure in major mood disorders. (C) 2008 Published by Elsevier B.V.
Resumo:
Data were retrospectively collected from 69 Brazilian patients (45 boys) with growth hormone deficiency (GHD) who received exogenous growth hormone (GH) for a median duration of 4 years (range 1-13 years). Forty-two patients had multiple pituitary hormone deficiencies and 27 had isolated GHD. Peak GH was <7 ng/ml (IRMA) or <3.2 ng/ml (IFMA) after two stimulation tests.. Therapy was started at median age of 10.0 years (range 2.2-21.6 years), bone age of 5.8 years (0.5-13.5 years) and height standard deviation score -4.4 (range -9.3 to -1.6). MRI revealed pituitary abnormalities in 87% of patients. Homozygous mutations in PROP-1, GHRH-R, GH-1 or HESX-1 genes were found in 12 patients. Mean height velocities were 3.3 pretreatment and 10.3, 7.8, 7.4 and 6.4 cm/yr, respectively, during 1-4 years of treatment with GH. In conclusion, the high prevalence (96%) of genetic and/or pituitary abnormalities probably reflects the stringent diagnostic criteria used, and GH replacement resulted in significant catch-up growth.
Resumo:
Background: Decreased signal intensity in the corpus callosum, reported in adult bipolar disorder patients, has been regarded as an indicator of abnormalities in myelination. Here we compared the callosal signal intensity of children and adolescents with bipolar disorder to that of matched healthy subjects, to investigate the hypothesis that callosal myelination is abnormal in pediatric bipolar patients. Methods: Children and adolescents with DSM-lV bipolar disorder (n=16, mean age +/- S.D. = 15.5 +/- 3.4 y) and matched healthy comparison subjects (n=21, mean age +/- S.D.=16.9 3.8 y) underwent a 1.5 T MRI brain scan. Corpus callosuin signal intensity was measured using an Apple Power Mac G4 running NIH Image 1.62 software. Results: Bipolar children and adolescents had significantly lower corpus callosum signal intensity for all callosal sub-regions (genu, anterior body, posterior body, isthmus and splenium) compared to healthy subjects (ANCOVA, all p < 0.05, age and gender as covariates). Limitations: Relatively small sample size. Conclusions: Abnormalities in corpus callosum, probably due to altered myelination during neurodevelopment, may play a role in the pathophysiology of bipolar disorder among children and adolescents. (c) 2007 Elsevier B.V All rights reserved.
Resumo:
Kallmann syndrome (KS) is a developmental disease characterized by the association of isolated hypogonadotropic hypogonadism and anosmia/hyposmia. We report an unusual presentation of two females with KS and empty sella. These females, aged at 20 and 29-year-old, presented primary amenorrhea with prepubertal estradiol and low gonadotropin levels. No other significant clinical signs were observed. Empty sella was observed on MRI in both cases. Sequencing of FGFR1 gene, recently implicated in autosomal form of KS, was performed and one splicing mutation (IVS14 + 1G > A) was identified in one patient.
Resumo:
Patella stabilizer muscle response and patellar kinematics were evaluated in 19 women with anterior knee pain (AKP) and 20 healthy women during maximum voluntary isometric contraction (MVIC) with the knee positioned at 15 degrees, 30 degrees and 45 degrees flexion during open (OKC) and closed (CKC) kinetic chain exercises. Patellar kinematics was evaluated through patellar tilt and displacement, and the electrical activity of patellar stabilizers through the root mean square normalized during MVIC and OKC with the knee at 90 degrees flexion. Data revealed that the vastus medialis oblique muscle (VMO) was more active in the control group compared to the AKP group during OKC exercises with the knee at 45 degrees flexion. However, no difference in the patellar kinematics was observed between these groups; nevertheless, the correlation between these parameters also showed, with the knee at 45 degrees flexion, that lateral patellar tilt increase was associated with a reduction in the activity of lateral patellar stabilizers in the control group and with an increase in the VMO activity in the AKP group. In conclusion, electrical activity is an important factor in evaluating AKP and in AKP treatment evolution. (C) 2010 Elsevier Ltd. All rights reserved.
Resumo:
Objective. The purpose of this series was to determine the frequency of abductor mechanism avulsion by sonography after total hip arthroplasty with the Hardinge approach (J Bone Joint Surg Br 1982; 64:17-19) and its relationship to the presence of insufficiency of this musculature in the postoperative period. Methods. Thirty-four consecutive patients were prospectively accessed in the postoperative period of hip arthroplasty by the Trendelenburg test, hip sonography, and abductor muscle electromyography. In patients who were found to have clinical insufficiency of the abductor musculature, we also measured the femoral offset in the preoperative and postoperative radiographs. Hip sonography was performed by an experienced musculoskeletal radiologist blinded to the other tests, and the tendons of the gluteus medius and gluteus minimus were visualized on longitudinal and transverse sections with a 7- to 10-MHz linear transducer. Results. Eight patients presented clinical insufficiency of the abductor musculature as detected by the Trendelenburg test. Four of these 8 patients with abductor insufficiency presented tendinous avulsion detected by sonography. One of the 4 patients with abductor insufficiency and normal sonographic findings had a decrease in the femoral offset caused by the arthroplasty itself. Two patients presented electromyographic changes of the abductor musculature, with no tendinous avulsion detected by sonography and no abductor insufficiency. Conclusions. We concluded that in patients undergoing total hip arthroplasty by the Hardinge approach in whom insufficiency of the abductor musculature develops, sonography is an interesting method of investigation because it identified the cause of this problem in most of our patients.
Resumo:
BACKGROUND: The development of newer diagnostic technologies has reduced the need for invasive electroencephalographic (EEG) studies in identifying the epileptogenic zone, especially in adult patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS). OBJECTIVE: To evaluate ictal single photon emission computed tomography (SPECT) in the evaluation and treatment of patients with MTLE-HS. METHODS: MTLE patients were randomly assigned to those with (SPECT, n = 124) and without ictal SPECT (non-SPECT, n = 116) in an intent-to-treat protocol. Primary end points were the proportion of patients with invasive EEG studies, and those offered surgery. Secondary end points were the length of hospital stay and the proportion of patients with secondarily generalized seizures (SGS) during video-EEG, postsurgical seizure outcome, and hospital cost. RESULTS: The proportion of patients offered surgery was similar in the SPECT (85%) and non-SPECT groups (81%), as well as the proportion that had invasive EEG studies (27% vs 23%). The mean duration of hospital stay was 1 day longer for the SPECT group (P < 0.001). SGS occurred in 51% of the SPECT and 26% of the non-SPECT group (P < 0.001). The cost of the presurgical evaluation was 35% higher for the SPECT compared with the non-SPECT group (P < 0.001). The proportion of patients seizure-free after surgery was similar in the SPECT (59%) compared with non-SPECT group (54%). CONCLUSION: Ictal-SPECT did not add localizing value beyond what was provided by EEG-video telemetry and structural MRI that altered the surgical decision and outcome for MTLE-HS patients. Ictal-SPECT increased hospital stay was associated with increased costs and a higher chance of SGS during video-EEG monitoring. These findings support the notion that a protocol including ictal SPECT is equivalent to one without SPECT in the presurgical evaluation of adult patients with MTLE-HS.
Resumo:
In the present study, we evaluated the preoperative demographic, clinical, and neuropsychological variables that could predict postoperative seizure outcome in a group of pediatric epileptic patients. We studied 40 consecutive pediatric patients, ages ranging from 6 to 16 years, that underwent resective surgery for the treatment of medically intractable epilepsy at the Clinical Hospital of RibeirA o pound Preto School of Medicine. We performed ictal electroencephalography (EEG), interictal EEG, magnetic resonance imaging (MRI), and a preoperative neuropsychological assessment in the presurgical workup. The following factors were correlated with seizure outcome: (1) duration of epilepsy, (2) surgery localization, (3) localized Neuropsychological (NPS) Evaluation, (4) ictal EEG, (5) interictal EEG, and (6) MRI. Mental retardation, NPS tests, and the other demographic variables failed to correlate with seizure reduction. The identification of predictor variables of epilepsy surgery outcome could improve the epileptic prognosis and guarantee the children`s full potential development.
Resumo:
Purpose: The purpose of our study was to compare signal characteristics and image qualities of MR imaging at 3.0 T and 1.5 T in patients with diffuse parenchymal liver disease. Materials and methods: 25 consecutive patients with diffuse parenchymal liver disease underwent abdominal MR imaging at both 3.0 T and 1.5 T within a 6-month interval. A retrospective study was conducted to obtain quantitative and qualitative data from both 3.0 T and 1.5 T MRI. Quantitative image analysis was performed by measuring the signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) by the Students t-test. Qualitative image analysis was assessed by grading each sequence on a 3- and 4-point scale, regarding the presence of artifacts and image quality, respectively. Statistical analysis consisted of the Wilcoxon signed-rank test. Results: the mean SNRs and CNRs of the liver parenchyma and the portal vein were significantly higher at 3.0 T than at 1.5 T on portal and equilibrium phases of volumetric interpolated breath-hold examination (VIBE) images (P < 0.05). The mean SNRs were significantly higher at 3.0 T than at 1.5 T on T1-weighted spoiled gradient echo (SGE) images (P < 0.05). However, there were no significantly differences on T2-weighted short-inversion-time inversion recovery (STIR) images. Overall image qualities of the 1.5 T noncontrast T1- and T2-weighted sequences were significantly better than 3.0 T (P < 0.01). In contrast, overall image quality of the 3.0 T post-gadolinium VIBE sequence was significantly better than 1.5 T (P< 0.01). Conclusions: MR imaging of post-gadolinium VIBE sequence at 3.0 T has quantitative and qualitative advantages of evaluating for diffuse parenchymal liver disease. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Background Autologous non-myeloablative haemopoietic stem cell transplantation is a method to deliver intense immune suppression. We evaluated the safety and clinical outcome of autologous non-myeloablative haemopoietic stem cell transplantation in patients with retapsing-remitting multiple sclerosis (MS) who had not responded to treatment with interferon beta. Methods Eligible patients had relapsing-remitting MS, attended Northwestern Memorial Hospital, and despite treatment with interferon beta had had two corticosteroid-treated relapses within the previous 12 months, or one relapse and gadolinium-enhancing lesions seen on MRI and separate from the relapse. Peripheral blood haemopoietic stem cells were mobilised with 2 g per m(2) cyclophosphamide and 10 mu g per kg per day filgrastim. The conditioning regimen for the haemopoietic stem cells was 200 mg per kg cyclophosphamide and either 20 mg alemtuzumab or 6 mg per kg rabbit antithymocyte globulin. Primary outcomes were progression-free survival and reversal of neurological disability at 3 years post-transplantation. We also sought to investigate the safety and tolerability of autologous non-myeloablative haemopoietic stem cell transplantation. Findings Between January 2003, and February, 2005, 21 patients were treated. Engraftment of white blood cells and platelets was on median day 9 (range day 8-11) and patients were discharged from hospital on mean day 11 (range day 8-13). One patient had diarrhoea due to Clostridium difficile and two patients had dermatomal zoster. Two of the 17 patients receiving alemtuzumab developed late immune thrombocytopenic purpura that remitted with standard therapy. 17 of 21 patients (81%) improved by at least 1 point on the Kurtzke expanded disability status scale (EDSS), and five patients (24%) relapsed but achieved remission after further immunosuppression. After a mean of 37 months (range 24-48 months), all patients were free from progression (no deterioration in EDSS score), and 16 were free of relapses. Significant improvements were noted in neurological disability, as determined by EDSS score (p<0.0001), neurological rating scale score (p=0.0001), paced auditory serial addition test (p=0.014), 25-foot walk (p<0.0001), and quality of life, as measured with the short form-36 (SF-36) questionnaire (p<0.0001). Interpretation Non-myeloablative autologous haemopoietic stem cell transplantation in patients with relapsing-remitting MS reverses neurological deficits, but these results need to be confirmed in a randomised trial.
Resumo:
Objective: To investigate pathophysiological factors underlying the presence of interictal hyper-perfusion within the limits of the polymicrogyric (PMG) cortex in epileptic patients. Methods: Retrospective observational study on interictal perfusion by Single Photon Emission Computed Tomography (SPECT) in 16 patients with PMG and its correlations with a number of clinical and neurophysiological variables. Patients underwent video-EEG monitoring, neurological and psychiatric assessments, invasive EEG, and the interictal SPECT coregistered to Magnetic Resonance Imaging (MRI). Results: Patients with interictal hyperperfusion within the PMG cortex had a significantly higher spike rate on interictal EEG than patients with normal perfusion. Interictal hyperperfusion was not correlated to sex, age at epilepsy onset, age at evaluation, number of seizures per month, presence of initial precipitating insult (IPI), abnormal neurological examination, EEG findings, ictal serniology, and seizure outcome. The high interictal spike rate did not correlate to a high frequency of seizures per month. Conclusions: Our work provides further evidences for an intrinsic epileptogenesis of the PMG cortex during the interictal state, which accounts for the major rote of PMG tissue in seizure generation. These results might help to increase our understanding about epileptogenesis related to the PMG cortex, providing new toots for more tailored epilepsy surgery in PMG patients. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Objective: To investigate the association of different types of magnetic resonance imaging (MRI)-detected medial meniscal pathology with subregional cartilage loss in the medial tibiofemoral compartment. Methods: A total of 152 women aged >= 40 years, with and without knee osteoarthritis (OA) were included in a longitudinal 24-month observational study. Spoiled gradient recalled acquisitions at steady state (SPGR) and T2-weighted fat-suppressed MRI sequences were acquired. Medial meniscal status of the anterior horn (AH), body, and posterior horn (PH) was graded at baseline: 0 (normal), 1 (intrasubstance meniscal signal changes), 2 (single tears), and 3 (complex tears/maceration). Cartilage segmentation was performed at baseline and 24-month follow-up in various tibiofemoral subregions using computation software. Multiple linear regression models were applied for the analysis with cartilage loss as the outcome. In a first model, the results were adjusted for age and body mass index (BMI). In a second model, the results were adjusted for age, BMI and medial meniscal extrusion. Results: After adjusting for age, BMI, and medial meniscal extrusion, cartilage loss in the total medial tibia (MT) (0.04 mm, P=0.04) and the external medial tibia (eMT) (0.068 mm, P=0.04) increased significantly for compartments with grade 3 lesions. Cartilage loss in the total central medial femoral condyle (cMF) (0.071 mm, P=0.03) also increased significantly for compartments with grade 2 lesions. Cartilage loss at the eMT was significantly related to tears of the PH (0.074 mm; P=0.03). Cartilage loss was not significantly increased for compartments with grade 1 lesions. Conclusion: The protective function of the meniscus appears to be preserved in the presence of intrasubstance meniscal signal changes. Prevalent single tears and meniscal maceration were found to be associated with increased cartilage loss in the same compartment, especially at the PH. (C) 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
Resumo:
MRI is an important tool for investigating breast cancer. Although recognized as the method of choice for screening highrisk patients, and for other indications the role of MRI for lesion characterization remains controversial. Recently some authors have advocated the use of morphologic and postcontrast features for this purpose. Quantitative breast MRI techniques have not been applied extensively in breast diseases. Magnetization transfer (MT) is a quantitative MR technique commonly used to investigate neurological diseases. In breast diseases the use of MT has been limited to improving visualization of areas of enhancement in postcontrast images. The purpose of this study was to evaluate the feasibility and utility of MT in discriminating benign from malignant breast lesions. Fifty-two lesions, Bl-RADS 4 and 5, from 49 patients, were prospectively evaluated using the MT ratio (MTR). Patients were divided into two groups: benign and malignant lesions. The MTR of fat, pectoralis major muscle, fibroglandular tissue, and breast lesions were calculated. A statistically significant difference was found between MTR from benign and malignant lesions (P < 0.001). Preliminary results suggest that MT can be used to evaluate breast lesions. Further studies are necessary to better define the utility and applicability of this technique.
Resumo:
Functional brain imaging techniques such as functional MRI (fMRI) that allow the in vivo investigation of the human brain have been exponentially employed to address the neurophysiological substrates of emotional processing. Despite the growing number of fMRI studies in the field, when taken separately these individual imaging studies demonstrate contrasting findings and variable pictures, and are unable to definitively characterize the neural networks underlying each specific emotional condition. Different imaging packages, as well as the statistical approaches for image processing and analysis, probably have a detrimental role by increasing the heterogeneity of findings. In particular, it is unclear to what extent the observed neurofunctional response of the brain cortex during emotional processing depends on the fMRI package used in the analysis. In this pilot study, we performed a double analysis of an fMRI dataset using emotional faces. The Statistical Parametric Mapping (SPM) version 2.6 (Wellcome Department of Cognitive Neurology, London, UK) and the XBAM 3.4 (Brain Imaging Analysis Unit, Institute of Psychiatry, Kings College London, UK) programs, which use parametric and non-parametric analysis, respectively, were used to assess our results. Both packages revealed that processing of emotional faces was associated with an increased activation in the brain`s visual areas (occipital, fusiform and lingual gyri), in the cerebellum, in the parietal cortex, in the cingulate cortex (anterior and posterior cingulate), and in the dorsolateral and ventrolateral prefrontal cortex. However, blood oxygenation level-dependent (BOLD) response in the temporal regions, insula and putamen was evident in the XBAM analysis but not in the SPM analysis. Overall, SPM and XBAM analyses revealed comparable whole-group brain responses. Further Studies are needed to explore the between-group compatibility of the different imaging packages in other cognitive and emotional processing domains. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
We describe the long-term clinical outcome of a patient with Leigh-like syndrome presenting as an early onset encephalopathy and peripheral neuropathy caused by the T8993G mutation in the mitochondrial DNA (mtDNA). Clinical follow-up for 20 years revealed a peculiar pattern of slow disease progression, characterized by the addition of new minor deficits, while worsening of previous symptoms was mild. Brain MRI revealed cerebellar atrophy, diffuse demyelination of corona radiata and parietal white matter, and bilateral and symmetrical putaminal lesions. The proportion of mutant mtDNAs in blood was 72% (+/- 0.02%) and in skeletal muscle was 81% (+/- 0.4%). Leigh-like syndrome caused by the T8993G mtDNA mutation is a progressive disease, although not necessarily associated with an aggressive clinical course. (C) 2009 Elsevier B.V. All rights reserved.