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1.
J Neuroradiol ; 50(2): 271-277, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34800564

RESUMO

BACKGROUND: In subjects with isolated growth hormone deficiency (IGHD), recombinant human growth hormone (rhGH) is an approved method to achieve potential mid-parental height. However, data reporting rhGH treatment response in terms of brain structure volumes were scarce. We report the volumetric changes of the pituitary gland, basal ganglia, corpus callosum, thalamus, hippocampus and amygdala in these subjects post rhGH treatment. MATERIALS AND METHODS: This was a longitudinal study of eight IGHD subjects (2 males, 6 females) with a mean age of 11.1 ± 0.8 years and age-matched control groups. The pituitary gland, basal ganglia and limbic structures volumes were obtained using 3T MRI voxel-based morphology. The left-hand bone age was assessed using the Tanner-Whitehouse method. Follow-up imaging was performed after an average of 1.8 ± 0.4 years on rhGH. RESULTS: Subjects with IGHD had a smaller mean volume of the pituitary gland, right thalamus, hippocampus, and amygdala than the controls. After rhGH therapy, these volumes normalized to the age-matched controls. Corpus callosum of IGHD subjects had a larger mean volume than the controls and did not show much volume changes in response to rhGH therapy. There were changes towards normalization of bone age deficit of IGHD in response to rhGH therapy. CONCLUSION: The pituitary gland, hippocampus, and amygdala volumes in IGHD subjects were smaller than age-matched controls and showed the most response to rhGH therapy. Semi-automated volumetric assessment of pituitary gland, hippocampus, and amygdala using MRI may provide an objective assessment of response to rhGH therapy.


Assuntos
Nanismo Hipofisário , Hormônio do Crescimento Humano , Masculino , Feminino , Criança , Humanos , Hormônio do Crescimento Humano/uso terapêutico , Hormônio do Crescimento , Estudos Longitudinais , Hipófise/diagnóstico por imagem
2.
J Magn Reson Imaging ; 53(2): 437-444, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32918328

RESUMO

BACKGROUND: Charcot-Marie-Tooth (CMT) disease is diagnosed through clinical findings and genetic testing. While there are neurophysiological tools and clinical functional scales in CMT, objective disease biomarkers that can facilitate in monitoring disease progression are limited. PURPOSE: To investigate the utility of diffusion tensor imaging (DTI) in determining the microstructural integrity of sciatic and peroneal nerves and its correlation with the MRI grading of muscle atrophy severity and clinical function in CMT as determined by the CMT neuropathy score (CMTNS). STUDY TYPE: Prospective case-control. SUBJECTS: Nine CMT patients and nine age-matched controls. FIELD STRENGTH/SEQUENCE: 3 T T1 -weighted in-/out-of phase spoiled gradient recalled echo (SPGR) and DTI sequences. ASSESSMENT: Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD) values for sciatic and peroneal nerves were obtained from DTI. Muscle atrophy was graded according to the Goutallier classification using in-/out-of phase SPGRs. DTI parameters and muscle atrophy grades were compared between CMT and controls, and the relationship between DTI parameters, muscle atrophy grades, and CMTNS were assessed. STATISTICAL TESTS: The Wilcoxon Signed Ranks test was used to compare DTI parameters between CMT and controls. The relationship between DTI parameters, muscle atrophy grades, and CMTNS were analyzed using the Spearman correlation. Receiver operating characteristic (ROC) analyses of DTI parameters that can differentiate CMT from healthy controls were done. RESULTS: There was a significant reduction in FA and increase in RD of both nerves (P < 0.05) in CMT, with significant correlations between FA (negative; P < 0.05) and RD (positive; P < 0.05) with muscle atrophy grade. In the sciatic nerve, there was significant correlation between FA and CMTNS (r = -0.795; P < 0.05). FA and RD could discriminate CMT from controls with high sensitivity (77.8-100%) and specificity (88.9-100%). DATA CONCLUSION: There were significant differences of DTI parameters between CMT and controls, with significant correlations between DTI parameters, muscle atrophy grade, and CMTNS. Level of Evidence 2 Technical Efficacy Stage 2 J. MAGN. RESON. IMAGING 2021;53:437-444.


Assuntos
Doença de Charcot-Marie-Tooth , Imagem de Tensor de Difusão , Anisotropia , Doença de Charcot-Marie-Tooth/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Nervos Periféricos/diagnóstico por imagem , Estudos Prospectivos
3.
J Clin Densitom ; 24(3): 351-361, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32888777

RESUMO

Osteoporotic fractures are common in Parkinson's disease (PD). Standard dual-energy X-ray absorptiometry (DXA) measuring bone mineral density (BMD) at the femoral neck and lumbar spine (central sites) has suboptimal sensitivity in predicting fracture risk in the general population. An association between sarcopenia and osteoporosis in PD has not been studied. We compared BMD and osteoporosis prevalence in PD patients vs controls; determined the osteoporosis detection rates using central alone vs central plus distal radius DXA; and analyzed factors (in particular, sarcopenia) associated with osteoporosis. One hundred and fifty-six subjects (102 patients with PD, 54 spousal/sibling controls) underwent femoral neck-lumbar spine-distal radius DXA. Seventy-three patients and 46 controls were assessed for sarcopenia using whole-body DXA and handgrip strength. Patients underwent clinical and serum biochemical evaluations. PD patients had significantly lower body mass index compared to controls. After adjustment for possible confounders, distal radius BMD and T-scores were significantly lower in PD patients compared to controls, but not at the femoral neck/lumbar spine. With distal radius DXA, an additional 11.0% of patients were diagnosed with osteoporosis (32.0% to 43.0%), vs 3.7% in controls (33.3% to 37.0%) additionally diagnosed; this increase was largely driven by the markedly higher detection rate in female PD patients. Female gender (adjusted odds ratio [ORadjusted] = 11.3, 95% confidence interval [CI]: 2.6-48.6) and sarcopenia (ORadjusted = 8.4, 95% CI: 1.1-64.9) were independent predictors for osteoporosis in PD. Distal radius DXA increased osteoporosis detection, especially in female PD patients, suggesting that diagnostic protocols for osteoporosis in PD could be optimized. A close association between osteoporosis and sarcopenia was documented for the first time in PD, which has important implications for clinical management and future research.


Assuntos
Osteoporose , Fraturas por Osteoporose , Doença de Parkinson , Sarcopenia , Absorciometria de Fóton , Densidade Óssea , Feminino , Força da Mão , Humanos , Vértebras Lombares/diagnóstico por imagem , Osteoporose/diagnóstico por imagem , Osteoporose/epidemiologia , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/epidemiologia , Rádio (Anatomia) , Sarcopenia/diagnóstico por imagem , Sarcopenia/epidemiologia
4.
J Craniofac Surg ; 32(1): 355-359, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33156163

RESUMO

BACKGROUND: In syndromic craniosynostosis (SC), unlike persistent corneal irritation due to severe exophthalmos and increased intracranial pressure, optic canal (OC) stenosis has been scarcely reported to cause visual impairment. This study aimed to validate the OC volumetric and surface area measurement among SC patients. METHODS: Sixteen computed tomography scan of SC patients (8 months-6 years old) were imported to Materialise Interactive Medical Image Control System (MIMICS) and Materialise 3-matics software. Three-dimensional (3D) OC models were fabricated, and linear measurements were obtained. Mathematical formulas were used for calculation of OC volume and surface area from the 3D model. The same measurements were obtained from the software and used as ground truth. Data normality was investigated before statistical analyses were performed. Wilcoxon test was used to validate differences of OC volume and surface area between 3D model and software. RESULTS: The mean values for OC surface area for 3D model and MIMICS software were 103.19 mm2 and 31.27 mm2, respectively, whereas the mean for OC volume for 3D model and MIMICS software were 184.37 mm2 and 147.07 mm2, respectively. Significant difference was found between OC volume (P = 0.0681) and surface area (P = 0.0002) between 3D model and software. CONCLUSION: Optic canal in SC is not a perfect conical frustum thus making 3D model measurement and mathematical formula for surface area and volume estimation not ideal. Computer software remains the best modality to gauge dimensional parameter and is useful to elucidates the relationship of OC and eye function as well as aiding intervention in SC patients.


Assuntos
Craniossinostoses , Imageamento Tridimensional , Craniossinostoses/diagnóstico por imagem , Humanos , Software , Tomografia Computadorizada por Raios X
5.
Pediatr Radiol ; 50(9): 1277-1283, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32591982

RESUMO

BACKGROUND: Intrathecal and intravenous chemotherapy, specifically methotrexate, might contribute to neural microstructural damage. OBJECTIVE: To assess, by diffusion tensor imaging, microstructural integrity of white matter in paediatric patients with acute lymphoblastic leukaemia (ALL) following intrathecal and intravenous chemotherapy. MATERIALS AND METHODS: Eleven children diagnosed with de novo ALL underwent MRI scans of the brain with diffusion tensor imaging (DTI) prior to commencement of chemotherapy and at 12 months after diagnosis, using a 3-tesla (T) MRI scanner. We investigated the changes in DTI parameters in white matter tracts before and after chemotherapy using tract-based spatial statistics overlaid on the International Consortium of Brain Mapping DTI-81 atlas. All of the children underwent formal neurodevelopmental assessment at the two study time points. RESULTS: Whole-brain DTI analysis showed significant changes between the two time points, affecting several white matter tracts. The tracts demonstrated longitudinal changes of decreasing mean and radial diffusivity. The neurodevelopment of the children was near compatible for age at the end of ALL treatment. CONCLUSION: The quantification of white matter tracts changes in children undergoing chemotherapy showed improving longitudinal values in DTI metrics (stable fractional anisotropy, decreasing mean and radial diffusivity), which are incompatible with deterioration of microstructural integrity in these children.


Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Imagem de Tensor de Difusão , Metotrexato/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Substância Branca/efeitos dos fármacos , Substância Branca/ultraestrutura , Anisotropia , Mapeamento Encefálico/métodos , Criança , Pré-Escolar , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino
6.
Eur Radiol ; 26(7): 2019-29, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26560718

RESUMO

OBJECTIVES: We evaluated the feasibility of using chemical shift gradient-echo (GE) in- and opposed-phase (IOP) imaging to grade glioma. METHODS: A phantom study was performed to investigate the correlation of (1)H MRS-visible lipids with the signal loss ratio (SLR) obtained using IOP imaging. A cross-sectional study approved by the institutional review board was carried out in 22 patients with different glioma grades. The patients underwent scanning using IOP imaging and single-voxel spectroscopy (SVS) using 3T MRI. The brain spectra acquisitions from solid and cystic components were obtained and correlated with the SLR for different grades. RESULTS: The phantom study showed a positive linear correlation between lipid quantification at 0.9 parts per million (ppm) and 1.3 ppm with SLR (r = 0.79-0.99, p < 0.05). In the clinical study, we found that SLR at the solid portions was the best measure for differentiating glioma grades using optimal cut-points of 0.064 and 0.086 with classification probabilities for grade II (SII = 1), grade III (SIII = 0.50) and grade IV (SIV = 0.89). CONCLUSIONS: The results underscore the lipid quantification differences in grades of glioma and provide a more comprehensive characterization by using SLR in chemical shift GE IOP imaging. SLR in IOP sequence demonstrates good performance in glioma grading. KEY POINTS: • Strong correlation was seen between lipid concentration and SLR obtained using IOP • IOP sequence demonstrates significant differences in signal loss within the glioma grades • SLR at solid tumour portions was the best measure for differentiation • This sequence is applicable in a research capacity for glioma staging armamentarium.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Lipídeos/administração & dosagem , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/classificação , Neoplasias Encefálicas/patologia , Criança , Estudos Transversais , Estudos de Viabilidade , Feminino , Glioma/classificação , Glioma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Adulto Jovem
7.
Eur Radiol ; 26(12): 4404-4412, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26943134

RESUMO

OBJECTIVE: To compare the metabolite concentration of optic radiation in glaucoma patients with that of healthy subjects using Proton Magnetic Resonance Spectroscopy (1H-MRS). METHODS: 1H-MRS utilising the Single-Voxel Spectroscopy (SVS) technique was performed using a 3.0Tesla MRI on 45 optic radiations (15 from healthy subjects, 15 from mild glaucoma patients, and 15 from severe glaucoma patients). A standardised Volume of Interest (VOI) of 20 × 20 × 20 mm was placed in the region of optic radiation. Mild and severe glaucoma patients were categorised based on the Hodapp-Parrish-Anderson (HPA) classification. Mean and multiple group comparisons for metabolite concentration and metabolite concentration ratio between glaucoma grades and healthy subjects were obtained using one-way ANOVA. RESULTS: The metabolite concentration and metabolite concentration ratio between the optic radiations of glaucoma patients and healthy subjects did not demonstrate any significant difference (p > 0.05). CONCLUSION: Our findings show no significant alteration of metabolite concentration associated with neurodegeneration that could be measured by single-voxel 1H-MRS in optic radiation among glaucoma patients. KEY POINTS: • Glaucoma disease has a neurodegenerative component. • Metabolite changes have been observed in the neurodegenerative process in the brain. • Using SVS, no metabolite changes in optic radiation were attributed to glaucoma.


Assuntos
Biomarcadores/metabolismo , Glaucoma de Ângulo Aberto/patologia , Espectroscopia de Prótons por Ressonância Magnética/métodos , Adulto , Idoso , Análise de Variância , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Colina/metabolismo , Creatina/metabolismo , Estudos Transversais , Feminino , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/metabolismo , Fibras Nervosas/patologia , Nervo Óptico/metabolismo , Doses de Radiação , Adulto Jovem
8.
J Oral Maxillofac Surg ; 74(6): 1197.e1-1197.e10, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26917201

RESUMO

PURPOSE: The aim of the present study was to establish the incidence of maxillofacial (MF) injury accompanying mild traumatic brain injury (mTBI) and the associated neurocognitive deficits and white matter changes. MATERIALS AND METHODS: A prospective review of 41 patients with mTBI and maxillofacial injury (with or without intracranial lesion) due to motor vehicle accidents who had admission computed tomography (CT), neurocognitive evaluation, and quantitative diffusion tensor imaging available was performed during admission and at 6 months of follow-up. Descriptive statistics were used for the demographic data, and a paired t test and repeated measure analysis of variance were used to establish the intergroup differences and susceptibility. RESULTS: The included patients were relatively young adults, with a mean age of 27.3 ± 8.8 years and 11.3 ± 2.1 years of education. Of the 41 patients, 20 (48.8%) had maxillofacial injuries involving the soft tissue and muscles, 18 (43.9%) had facial bone fractures, and 3 (7.3%) had mixed injuries. Of the 41 patients with MF injuries, 28 (68.3%) had intracranial abnormalities found on the admission CT scan. Executive function and attention were significantly altered across the time points, with patients with both MF injury and an intracranial lesion doing poorly at baseline but with improvement 6 months later. In contrast, the patients with no visible intracranial lesion but with MF injuries remained impaired, with signs of a slowed recovery. The fractional anisotropy of the genu of the corpus callosum, anterior limb of the internal capsule, and cingulum for patients with MF injuries but without an intracranial lesion showed trends of reduced integrity over time. CONCLUSIONS: The presence of MF injury without any intracranial traumatic lesions in patients with mTBI increases the risk of short- and long-term neurocognitive derangement compared with patients with mTBI, MF injury, and intracranial traumatic lesions.


Assuntos
Concussão Encefálica/diagnóstico por imagem , Transtornos Cognitivos/etiologia , Traumatismos Maxilofaciais/diagnóstico por imagem , Acidentes de Trânsito , Adolescente , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/ultraestrutura , Concussão Encefálica/psicologia , Transtornos Cognitivos/diagnóstico por imagem , Imagem de Tensor de Difusão , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Traumatismos Maxilofaciais/psicologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estudos Prospectivos , Tomografia Computadorizada por Raios X , Adulto Jovem
9.
Eur Arch Otorhinolaryngol ; 272(11): 3109-13, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25205300

RESUMO

High acoustic noise level is one of the unavoidable side effects of 3 T magnetic resonance imaging (MRI). A case of hearing loss after 3 T MRI has been reported in this institution and hence this study. The objective of this study was to determine whether temporary threshold shift (TTS) in high frequency hearing occurs in patients undergoing 3 T MRI scans of the head and neck. A total of 35 patients undergoing head and neck 3 T MRI for various clinical indications were tested with pure tone audiometry in different frequencies including high frequencies, before and after the MRI scan. Any threshold change from the recorded baseline of 10 dB was considered significant. All patients were fitted with foamed 3 M earplugs before the procedure following the safety guidelines for 3 T MRI. The mean time for MRI procedure was 1,672 s (range 1,040-2,810). The noise dose received by each patient amounted to an average of 3,906.29% (1,415-9,170%). The noise dose was derived from a normograph used by Occupational Noise Surveys. This was calculated using the nomograph of L eq, L EX, noise dose and time. There was no statistically significant difference between the hearing threshold before and after the MRI procedures for all the frequencies (paired t test, P > 0.05). For patients using 3 M foamed earplugs, noise level generated by 3 T MRI during routine clinical sequence did not cause any TTS in high frequency hearing.


Assuntos
Limiar Auditivo/fisiologia , Neoplasias de Cabeça e Pescoço/patologia , Perda Auditiva Provocada por Ruído/etiologia , Imageamento por Ressonância Magnética/efeitos adversos , Ruído , Adolescente , Adulto , Idoso , Audiometria de Tons Puros , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
10.
Graefes Arch Clin Exp Ophthalmol ; 252(6): 995-1000, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24770532

RESUMO

PURPOSE: To measure optic nerve (ON) volume using 3 T magnetic resonance imaging (MRI), to correlate ON volume with retinal nerve fiber layer (RNFL) thickness, and to determine the viability of MRI as an objective tool in distinguishing glaucoma severity. METHODS: In this cross-sectional study, 30 severe glaucoma patients, 30 mild glaucoma patients and 30 age-matched controls were recruited. All subjects underwent standard automated perimetry, RNFL analysis and 3 T MRI examinations. Glaucoma patients were classified according to the Hodapp-Anderson-Parish classification. Pearson's correlation coefficient was used to correlate ON volume with RNFL, and receiver operating curve (ROC) analysis was performed to determine the sensitivity and specificity of ON volume in detecting glaucoma severity. RESULTS: Optic nerve volume was significantly lower in both the left and right eyes of the severe glaucoma group (168.70 ± 46.28 mm(3); 167.40 ± 45.36 mm(3)) than in the mild glaucoma group (264.03 ± 78.53 mm(3); 264.76 ± 78.88 mm(3)) and the control group (297.80 ± 71.45 mm(3); 296.56 ± 71.02 mm(3)). Moderate correlation was observed between: RNFL thickness and ON volume (r = 0.51, p <0.001), and in mean deviation of visual field and optic nerve volume (r = 0.60, p < 0.001). ON volume below 236 mm(3) was 96 % sensitive and 80 % specific for the detection of severe glaucoma. CONCLUSIONS: MRI measured optic nerve volume is a reliable method of assessing glaucomatous damage beyond the optic nerve head. A value of 236 mm(3) and below can be used to define severe glaucoma.


Assuntos
Glaucoma de Ângulo Fechado/diagnóstico , Glaucoma de Ângulo Aberto/diagnóstico , Imageamento por Ressonância Magnética , Fibras Nervosas/patologia , Doenças do Nervo Óptico/diagnóstico , Nervo Óptico/patologia , Células Ganglionares da Retina/patologia , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Glaucoma de Ângulo Fechado/classificação , Glaucoma de Ângulo Aberto/classificação , Humanos , Pressão Intraocular/fisiologia , Pessoa de Meia-Idade , Variações Dependentes do Observador , Disco Óptico/patologia , Doenças do Nervo Óptico/classificação , Tamanho do Órgão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Campos Visuais/fisiologia
11.
Emerg Infect Dis ; 19(12): 1989-91, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24274071

RESUMO

An outbreak of fever associated with myalgia and myositis occurred in 2012 among 89 of 92 college students and teachers who visited Pangkor Island, Malaysia. The Sarcocystis nesbitti 18S rRNA gene and sarcocysts were obtained from muscle tissues of 2 students. Our findings indicate emergence of S. nesbitti infections in humans in Malaysia.


Assuntos
Surtos de Doenças , Sarcocystis/classificação , Sarcocistose/epidemiologia , Genes de Protozoários , Humanos , Malásia/epidemiologia , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 18S , Sarcocystis/genética , Sarcocystis/isolamento & purificação , Sarcocistose/diagnóstico , Sarcocistose/parasitologia
12.
Eur Radiol ; 23(6): 1459-66, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23300042

RESUMO

OBJECTIVE: To develop a decision tree based on standard magnetic resonance imaging (MRI) and diffusion tensor imaging to differentiate multiple system atrophy (MSA) from Parkinson's disease (PD). METHODS: 3-T brain MRI and DTI (diffusion tensor imaging) were performed on 26 PD and 13 MSA patients. Regions of interest (ROIs) were the putamen, substantia nigra, pons, middle cerebellar peduncles (MCP) and cerebellum. Linear, volumetry and DTI (fractional anisotropy and mean diffusivity) were measured. A three-node decision tree was formulated, with design goals being 100 % specificity at node 1, 100 % sensitivity at node 2 and highest combined sensitivity and specificity at node 3. RESULTS: Nine parameters (mean width, fractional anisotropy (FA) and mean diffusivity (MD) of MCP; anteroposterior diameter of pons; cerebellar FA and volume; pons and mean putamen volume; mean FA substantia nigra compacta-rostral) showed statistically significant (P < 0.05) differences between MSA and PD with mean MCP width, anteroposterior diameter of pons and mean FA MCP chosen for the decision tree. Threshold values were 14.6 mm, 21.8 mm and 0.55, respectively. Overall performance of the decision tree was 92 % sensitivity, 96 % specificity, 92 % PPV and 96 % NPV. Twelve out of 13 MSA patients were accurately classified. CONCLUSION: Formation of the decision tree using these parameters was both descriptive and predictive in differentiating between MSA and PD. KEY POINTS: • Parkinson's disease and multiple system atrophy can be distinguished on MR imaging. • Combined conventional MRI and diffusion tensor imaging improves the accuracy of diagnosis. • A decision tree is descriptive and predictive in differentiating between clinical entities. • A decision tree can reliably differentiate Parkinson's disease from multiple system atrophy.


Assuntos
Imageamento por Ressonância Magnética/métodos , Atrofia de Múltiplos Sistemas/diagnóstico , Doença de Parkinson/diagnóstico , Idoso , Anisotropia , Mapeamento Encefálico/métodos , Árvores de Decisões , Diagnóstico Diferencial , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Fatores de Tempo
13.
Childs Nerv Syst ; 29(1): 159-62, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22996826

RESUMO

BACKGROUND: Intraventricular haemorrhage is the most common cause of hydrocephalus in a pre-term baby and may require surgical intervention depending on severity. CLINICAL CASE: This case illustrates foraminal septae as a subtle cause of progressive quadriventricular hydrocephalus in a child born pre-term with a history of grade III intraventricular haemorrhage. The septae within the fourth ventricular exits were clearly demonstrated with 3D-FIESTA (fast imaging employing steady-state acquisition) MRI acquisitions and assisted in differentiation from communicating hydrocephalus. This finding guided the decision to a successful endoscopic third ventriculostomy. CONCLUSION: 3D-FIESTA sequence is recommended for investigating children with hydrocephalus secondary to intraventricular haemorrhage due to its diagnostic potential and implications on surgical technique.


Assuntos
Hemorragia Cerebral/complicações , Fontanelas Cranianas/diagnóstico por imagem , Hidrocefalia/etiologia , Complicações Pós-Operatórias , Nascimento Prematuro/fisiopatologia , Ventriculostomia/efeitos adversos , Hemorragia Cerebral/diagnóstico , Feminino , Humanos , Hidrocefalia/diagnóstico , Imageamento Tridimensional , Lactente , Ventrículos Laterais/patologia , Imageamento por Ressonância Magnética , Radiografia
14.
Eur Spine J ; 22 Suppl 3: S443-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23233216

RESUMO

PURPOSE: In this article, we review the English literature of calcified pseudomeningoceles in the lumbar region. METHODS: A systematic review using the Medline Database using the varied nomenclature for pseudomeningoceles, as well as reviewing the reference lists of relevant article found. RESULTS: We discuss the different pathological theories on formation of a pseudomeningocele, the formation of a calcified wall and the optimal management for this entity. To date, 17 cases have been described, of which 13 are reviewed here. Calcification of pseudomeningocele is a rare entity and in the lumbar spine this occurs postsurgically. The only predisposing factor is prior surgery to the lumbar spine. Computer tomography, magnetic resonance imaging (MRI) and MRI myelography in combination are the preoperative investigations of choice. The radiological work-up can be preoperatively diagnostic and is important in the surgical planning. CONCLUSIONS: The treatment is surgicel removal and the decision to treat is based on patient symptoms and correlating these with imaging. There is an average reported follow-up of 1.7 years postoperatively for these patients and the reported outcome after surgery is good.


Assuntos
Calcinose/patologia , Meningocele/patologia , Procedimentos Ortopédicos/efeitos adversos , Feminino , Humanos , Vértebras Lombares , Meningocele/etiologia , Pessoa de Meia-Idade
15.
Neuroimaging Clin N Am ; 33(1): 43-56, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36404046

RESUMO

MR imaging is essential in diagnosing viral encephalitis. Clinical features, cerebrospinal fluid analysis and pathogen confirmation by polymerase chain reaction can be supported by assessing imaging features. MR imaging patterns with typical locations can identify pathogens such as temporal lobe for herpes simplex virus type 1; bilateral thalami for Japanese encephalitis and influenza virus ; and brainstem for enterovirus and rabies. In this article, we have reviewed representative viral encephalitis and its MR imaging patterns. In addition, we also presented acute viral encephalitis without typical MR imaging patterns, such as dengue and varicella-zoster virus encephalitis.


Assuntos
Encefalite Viral , Humanos , Encefalite Viral/diagnóstico por imagem , Encefalite Viral/líquido cefalorraquidiano , Imageamento por Ressonância Magnética , Tronco Encefálico , Reação em Cadeia da Polimerase , Lobo Temporal
16.
SN Comput Sci ; 4(2): 141, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36624807

RESUMO

Coronavirus disease 2019 (COVID-19) is a disease caused by a novel strain of coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), severely affecting the lungs. Our study aims to combine both quantitative and qualitative analysis of the convolutional neural network (CNN) model to diagnose COVID-19 on chest X-ray (CXR) images. We investigated 18 state-of-the-art CNN models with transfer learning, which include AlexNet, DarkNet-19, DarkNet-53, DenseNet-201, GoogLeNet, Inception-ResNet-v2, Inception-v3, MobileNet-v2, NasNet-Large, NasNet-Mobile, ResNet-18, ResNet-50, ResNet-101, ShuffleNet, SqueezeNet, VGG-16, VGG-19, and Xception. Their performances were evaluated quantitatively using six assessment metrics: specificity, sensitivity, precision, negative predictive value (NPV), accuracy, and F1-score. The top four models with accuracy higher than 90% are VGG-16, ResNet-101, VGG-19, and SqueezeNet. The accuracy of these top four models is between 90.7% and 94.3%; the F1-score is between 90.8% and 94.3%. The VGG-16 scored the highest accuracy of 94.3% and F1-score of 94.3%. The majority voting with all the 18 CNN models and top 4 models produced an accuracy of 93.0% and 94.0%, respectively. The top four and bottom three models were chosen for the qualitative analysis. A gradient-weighted class activation mapping (Grad-CAM) was used to visualize the significant region of activation for the decision-making of image classification. Two certified radiologists performed blinded subjective voting on the Grad-CAM images in comparison with their diagnosis. The qualitative analysis showed that SqueezeNet is the closest model to the diagnosis of two certified radiologists. It demonstrated a competitively good accuracy of 90.7% and F1-score of 90.8% with 111 times fewer parameters and 7.7 times faster than VGG-16. Therefore, this study recommends both VGG-16 and SqueezeNet as additional tools for the diagnosis of COVID-19.

17.
Curr Med Imaging ; 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37170974

RESUMO

20% of brain tumor patients present with seizures at the onset of diagnosis, while a further 25-40% develop epileptic seizures as the tumor progresses. Tumor-related epilepsy (TRE) is a condition in which the tumor causes recurring, unprovoked seizures. The occurrence of TRE differs between patients, along with the effectiveness of treatment methods. Therefore, determining the tumor properties that correlate with epilepsy can help guide TRE treatment. This article reviews the MRI sequences and image post-processing algorithms in the study of TRE. It focuses on epilepsy caused by glioma tumors because it is the most common type of malignant brain tumor and it has a high prevalence of epilepsy. In correlational TRE studies, conventional MRI sequences and diffusion-weighted MRI (DWI) are used to extract variables related to the tumor radiological characteristics, called imaging factors. Image post-processing is used to correlate the imaging factors with the incidence of epilepsy. The earlier studies of TRE used univariate and multivariate analysis to study the correlations between specific variables and incidence of epilepsy. Later, studies used voxel-based morphometry and voxel lesion-symptom mapping. Radiomics has been recently used to post-process the images for the study of TRE. This article will discuss the limitation of the existing imaging modalities and post-processing algorithms. It ends with some suggestions and challenges for future TRE studies.

18.
Metabolites ; 12(12)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36557318

RESUMO

Gliomas are highly lethal tumours characterised by heterogeneous molecular features, producing various metabolic phenotypes leading to therapeutic resistance. Lipid metabolism reprogramming is predominant and has contributed to the metabolic plasticity in glioma. This systematic review aims to discover lipids alteration and their biological roles in glioma and the identification of potential lipids biomarker. This systematic review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Extensive research articles search for the last 10 years, from 2011 to 2021, were conducted using four electronic databases, including PubMed, Web of Science, CINAHL and ScienceDirect. A total of 158 research articles were included in this study. All studies reported significant lipid alteration between glioma and control groups, impacting glioma cell growth, proliferation, drug resistance, patients' survival and metastasis. Different lipids demonstrated different biological roles, either beneficial or detrimental effects on glioma. Notably, prostaglandin (PGE2), triacylglycerol (TG), phosphatidylcholine (PC), and sphingosine-1-phosphate play significant roles in glioma development. Conversely, the most prominent anti-carcinogenic lipids include docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and vitamin D3 have been reported to have detrimental effects on glioma cells. Furthermore, high lipid signals were detected at 0.9 and 1.3 ppm in high-grade glioma relative to low-grade glioma. This evidence shows that lipid metabolisms were significantly dysregulated in glioma. Concurrent with this knowledge, the discovery of specific lipid classes altered in glioma will accelerate the development of potential lipid biomarkers and enhance future glioma therapeutics.

19.
Neurol India ; 70(3): 1232-1234, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35864675

RESUMO

Background: Purposeless groaning is primarily encountered in patients with progressive supranuclear palsy and has also been reported to occur in advanced Parkinson's disease (PD). Objective: We describe a case of pronounced purposeless groaning occurring as a medication OFF-period nonmotor phenomenon in PD. To our knowledge, this has not been previously reported in the literature. Methods and Materials: We describe and provide video documentation of a patient with moderately advanced PD and motor fluctuations, in whom OFF-period groaning was reported by the family and observed during clinic consultations to be a prominent feature, occupying approximately 40% of his OFF periods as calculated from his PD diary. Conclusions: Although rare, OFF-period purposeless groaning in PD can be very disruptive and add significantly to caregiver burden. It is postulated to be a disinhibitory and perseverative behavior related to overactivation of the cingulo-periaqueductal circuit; further study is needed to delineate the underlying pathophysiological mechanisms.


Assuntos
Doença de Parkinson , Transtornos Parkinsonianos , Paralisia Supranuclear Progressiva , Humanos , Doença de Parkinson/complicações , Transtornos Parkinsonianos/complicações , Paralisia Supranuclear Progressiva/complicações
20.
Acad Radiol ; 29(4): e39-e48, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33992535

RESUMO

RATIONALE AND OBJECTIVES: Molecular studies have shown the changes in bone marrow fat in relation to altered hematopoiesis. This study aims to investigate the changes in the bone marrow fat in patients affected by ß-thalassemia by using chemical shift-encoded (CSE)-MRI. MATERIALS AND METHODS: Twenty-three subjects, comprising of six healthy (17-31 years old) and 17 ß-thalassemia subjects (19-39 years old), were scanned using a multiecho fast low angle shot sequence (0.94 × 0.94 × 3.00 mm3) and a stimulated echo acquisition mode sequence using 3T MRI. Bone marrow proton density fat fraction (PDFF) was quantified in the left femur of each subject. Regression and Bland-Altman analysis were used to analyze agreement between CSE-MRI and 1H-MRS. PDFF distribution was analyzed using Hartigan's dip test and the computed Wasserstein distances. Jonckheere-Terpstra trend analysis was performed to evaluate the effect of disease severity on PDFF distribution. RESULTS: An excellent agreement was found between PDFF measured using CSE-MRI with 1H-MRS (R2 = 0.91; bias =-1.41%). Healthy subjects showed left-skewed or bimodal PDFF distribution while ß-thalassemia subjects showed bimodal, normal or right-skewed distribution. Jonckheere-Terpstra test shows that PDFF distribution was increasingly different from the norm as disease severity increased (TJT = 166.0, z = 3.806, p < 0.05). Increase in variability of PDFF distribution within each subject group was also seen with increasing disease severity (TJT = 169.0, z = 3.971, p < 0.05). CONCLUSION: CSE-MRI is a promising tool to demonstrate spatial changes and variability in marrow fat distribution, resulting from ineffective erythropoiesis.


Assuntos
Medula Óssea , Talassemia beta , Tecido Adiposo/diagnóstico por imagem , Adolescente , Adulto , Medula Óssea/diagnóstico por imagem , Humanos , Fígado , Imageamento por Ressonância Magnética/métodos , Estudos Prospectivos , Água , Adulto Jovem , Talassemia beta/diagnóstico por imagem
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