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1.
Pediatr Radiol ; 54(5): 787-794, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38386022

RESUMO

BACKGROUND: Pituitary gland height reflects secretory activity of the hypothalamo-pituitary axis. OBJECTIVE: To assess the cumulative impact of fetal growth and sex on pituitary gland height in premature twins, dissociated from prematurity. MATERIALS AND METHODS: A retrospective study was conducted, assessing the pituitary gland height in 63 pairs of preterm twins, measured from T1-weighted magnetic resonance imaging (MRI). Auxological parameters, including body weight, body length, and head circumference, at birth and at the time of MRI, were used as proxies for fetal and postnatal growth, respectively. The study population was divided into two groups, using corrected age at around term equivalent as the cutoff point. Statistical analysis was performed using mixed-effects linear regression models. RESULTS: When pituitary gland height was evaluated at around term equivalent, a greater pituitary gland height, suggesting a more immature hypothamo-pituitary axis, was associated with the twin exhibiting lower auxological data at birth. The same association was observed when body weight and length at MRI were used as covariants. In the group evaluated after term equivalent, a smaller pituitary gland height, suggesting a more mature hypothamo-pituitary axis, was associated with male sex. This difference was observed in twin pairs with higher average body weight at birth, and in babies exhibiting higher auxological data at MRI. CONCLUSION: After isolating the effect of prematurity, at around term equivalent, pituitary gland height reflects the cumulative impact of fetal growth on the hypothalamo-pituitary axis. Subsequently, pituitary gland height shows effects of sex and of fetal and postnatal growth.


Assuntos
Recém-Nascido Prematuro , Imageamento por Ressonância Magnética , Hipófise , Humanos , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Recém-Nascido , Hipófise/diagnóstico por imagem , Hipófise/crescimento & desenvolvimento , Recém-Nascido Prematuro/crescimento & desenvolvimento , Estudos Retrospectivos , Fatores Sexuais , Gêmeos , Tamanho do Órgão
2.
Eur Radiol ; 32(11): 7522-7531, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35484338

RESUMO

OBJECTIVES: To explore the association between testicular volumetric apparent diffusion coefficient (ADC) histogram analysis metrics and histologic categories in nonobstructive azoospermia (NOA). The role of ADC histogram analysis in predicting the presence of spermatozoa, prior to testicular sperm extraction (TESE), was also investigated. METHODS: Forty-one NOA men and 17 age-matched controls underwent scrotal MRI with diffusion-weighted imaging. Histogram analysis of ADC data of the whole testis was performed. Metrics including mean, standard deviation, median, mode, 25th percentile, 75th percentile, skewness, kurtosis, and entropy of volumetric ADC histograms were calculated. Nonparametric statistical tests were used to assess differences in ADC histogram parameters between NOA histologic categories (hypospermatogenesis, severe hypospermatogenesis, early maturation arrest, and Sertoli cell-only syndrome) and normal testes and, between NOA with positive and negative sperm retrieval. RESULTS: Normal testes had a lower mean, median, mode, 25th percentile (p < 0.001), and 75th percentile of ADC (p = 0.001), compared to NOA histologic phenotypes. NOA with hypospermatogenesis had a lower 25th percentile of ADC compared to NOA with severe hypospermatogenesis. Regression analysis revealed that the 25th percentile of ADC had a moderately negative correlation with NOA histologic phenotype. The median ADC proved the most significant metric (p = 0.007) to predict the presence of sperm. CONCLUSIONS: Testicular volumetric ADC histogram parameters may contribute in the identification of the subpopulation of NOA men with a specific type of spermatogenic arrest. KEY POINTS: • Volumetric ADC histogram analysis metrics may be used as noninvasive markers of impaired spermatogenesis in nonobstructive azoospermia. • The 25th percentile of ADC proved useful in discriminating between NOA testes with hypospermatogenesis and severe hypospermatogenesis. • The median ADC proved the most significant parameter to predict the presence of viable spermatozoa prior to TESE.


Assuntos
Azoospermia , Infertilidade Masculina , Oligospermia , Humanos , Masculino , Azoospermia/diagnóstico por imagem , Azoospermia/patologia , Testículo/diagnóstico por imagem , Testículo/patologia , Oligospermia/patologia , Estudos Retrospectivos , Sêmen , Espermatogênese
3.
Neuroradiology ; 64(1): 197-204, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34342681

RESUMO

PURPOSE: Brain functional connectivity (FC) changes and microstructural abnormalities are reported in infants born moderate and late preterm (MLPT). We evaluated the effect of low-grade (grades I, II) intraventricular hemorrhage (IVH) in MLPT babies on brain structural connectivity (SC) and FC. METHODS: Babies born MLPT between January 2014 and May 2017 underwent brain ultrasound (US) at 72 h and 7 days after birth, and MRI at around term equivalent. The MRI protocol comprised T1- and T2-weighted sequences, diffusion tensor imaging (DTI), and resting-state functional MRI (fMRI). SC and FC were assessed using graph analysis. RESULTS: Of 350 MLPT neonates, 15 showed low-grade IVH on US at 72 h, for which brain MRI was available in 10. These 10 infants, with mean gestational age (GA) 34.0 ± 0.8 weeks, comprised the study group, and 10 MLPT infants of mean GA 33.9 ± 1.1 weeks, with no abnormalities on brain US and MRI, were control subjects. All study subjects presented modularity, small world topology, and rich club organization for both SC and FC. The patients with low-grade IVH had lower FC rich club coefficient and lower SC betweenness centrality in the left frontoparietal operculum, and lower SC rich club coefficient in the right superior orbitofrontal cortex than the control subjects. CONCLUSIONS: Topological and functional properties of mature brain connectivity are present in MLPT infants. IVH in these infants was associated with structural and functional abnormalities in the left frontoparietal operculum and right orbitofrontal cortex, regions related to language and cognition.


Assuntos
Imagem de Tensor de Difusão , Recém-Nascido Prematuro , Encéfalo/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética
4.
Neuroradiology ; 62(2): 251-255, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31828360

RESUMO

PURPOSE: Computed tomography (CT) for minor head injury exposes a large number of children to ionizing radiation, with an associated increased lifetime risk of malignancy. To study imaging practices for children with minor head injury and the level of awareness of radiologists of the current clinical decision rules for minor traumatic brain injury (TBI). METHODS: A questionnaire consisting of 17 questions was distributed electronically to 472 ESPR members. The questionnaire covered demographic information, employment status, years of experience and the current practice setting of the participants, the number of CTs performed for pediatric head trauma, awareness of clinical decision rules and use of shielding, pediatric CT protocol and MRI. RESULTS: The response rate was 18.4%. The majority of participants was aged over 50 years and was full-time consultants. Regarding decision rules, 73.8% of respondents cited the NICE head injury guidelines, and 79% reported that the decision to perform CT was agreed between specialists. Shielding was used by 58.3% and 67.4% applied a specific pediatric protocol. MRI was not used for pediatric head trauma by 70.6% of respondents, although always available in 68.6% of cases. The reported obstacles to MRI use were machine availability (42.7%), the long acquisition time (39%) and patients' intolerance (18.3%), and less frequently the cost and the need for sedation. CONCLUSION: There is room for decreasing the use of CT for pediatric minor TBI. The use of shielding and application of pediatric CT protocols constitute areas for improvement.


Assuntos
Traumatismos Craniocerebrais/diagnóstico por imagem , Padrões de Prática Médica/estatística & dados numéricos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Criança , Técnicas de Apoio para a Decisão , Feminino , Fidelidade a Diretrizes , Humanos , Masculino , Proteção Radiológica , Inquéritos e Questionários
5.
Acta Radiol ; 61(12): 1684-1694, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32212831

RESUMO

BACKGROUND: Fatigue and depression are among the most common manifestations of primary Sjögren syndrome (pSS), but information is lacking on the relationship with brain function and microstructural changes. PURPOSE: To investigate microstructural changes and brain connectivity in pSS, and to evaluate their relationship with fatigue and depression. MATERIAL AND METHODS: The study included 29 patients with pSS (mean age 61.2 ± 12.1 years; disease duration 10.5 ± 5.9 years) and 28 controls (mean age 58.4 ± 9.2 years). All the patients completed the Beck's depression and Fatigue Assessment Scale questionnaires. The imaging protocol consisted of: (i) standard magnetic resonance imaging (MRI) pulse sequences (FLAIR, 3D T1W); (ii) a diffusion tensor imaging pulse sequence; and (iii) a resting state functional MRI pulse sequence. Resting state brain networks and maps of diffusion metrics were calculated and compared between patients and controls. RESULTS: Compared with the controls, the patients with pSS and depression showed increased axial, radial, and mean diffusivity and decreased fractional anisotropy; those without depression showed decreased axial diffusivity in major white matter tracts (superior longitudinal fasciculus, inferior longitudinal fasciculus, corticospinal tract, anterior thalamic radiation, inferior fronto-occipital fasciculus, cingulum, uncinate fasciculus, and forceps minor-major). Decreased brain activation in the sensorimotor network was observed in the patients with pSS compared with the controls. No correlation was found between fatigue and structural or functional changes of the brain. CONCLUSION: pSS is associated with functional connectivity abnormalities of the somatosensory cortex and microstructural abnormalities in major white matter tracts, which are more pronounced in depression.


Assuntos
Depressão/fisiopatologia , Imagem de Tensor de Difusão/métodos , Síndrome de Sjogren/fisiopatologia , Degeneração Walleriana/diagnóstico por imagem , Degeneração Walleriana/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
6.
Andrologia ; 52(5): e13569, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32190931

RESUMO

Bilateral normal testes asymmetry represents an interesting phenomenon. The aim was to assess possible differences in the biochemical profile of bilateral normal testes by 3.0 T proton magnetic resonance spectroscopy (1H-MRS). Twenty-one men were examined with scrotal 3.0 T MRI, including a single-voxel point-resolved spectroscopy sequence. MR spectra were obtained by placing a volume of interest in the middle of each normal testis. Normalised metabolite concentrations, defined as ratios of the calculated metabolite concentrations relative to creatine (Cr) concentration, were compared between bilateral normal testes using Mann-Whitney U test. 1H-MRS allowed the detection of certain testicular metabolites, including total choline, Cr, myo-inositol, Glx, total lipids and macromolecules resonating at 0.9, 1.3 and 2.0 ppm. Normal left testis had higher median normalised concentrations of Glx (p = .002) and lactate (p = .041) compared with the normal right testis. Differences in concentrations of Glx were attributed to differences in glutamate (p = .020). Normal testes asymmetry is confirmed in this study by differences in the biochemical testicular profile, as assessed by 3.0 T 1H-MRS. Increase in levels of glutamate and lactate in normal left testis should be correlated with changes in metabolic pathways, specifically glycometabolism and amino acid metabolism.


Assuntos
Ácido Glutâmico/análise , Glutamina/análise , Ácido Láctico/análise , Testículo/química , Adolescente , Adulto , Creatina/análise , Creatina/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Ácido Láctico/metabolismo , Masculino , Pessoa de Meia-Idade , Espectroscopia de Prótons por Ressonância Magnética , Estudos Retrospectivos , Testículo/anatomia & histologia , Testículo/metabolismo , Adulto Jovem
7.
AJR Am J Roentgenol ; 213(3): 610-618, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31063417

RESUMO

OBJECTIVE. The aim of our study was to assess if testicular apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR) can be used as MRI parameters to predict the presence of spermatozoa retrieved after microdissection testicular sperm extraction (mTESE) in men with nonobstructive azoospermia (NOA). MATERIALS AND METHODS. The study included 49 men with NOA and 45 age-matched control subjects. Participants underwent scrotal MRI between June 2013 and January 2017, 1 day before mTESE. Testicular volume (TV), ADC, and MTR were measured. NOA testes were classified as follows: group 1, testes with higher Johnsen score of ≥ 8; and group 2, testes with higher Johnsen score of < 8. Nonparametric statistical tests were used to assess differences in TV, ADC, and MTR between men with NOA and control subjects, the two NOA groups, and NOA testes with positive sperm retrieval and NOA testes with negative sperm retrieval. RESULTS. TV (p < 0.001) was reduced and both ADC (p < 0.001) and MTR (p = 0.013) were increased in NOA testes compared with normal testes. A positive correlation between higher Johnsen score and TV (p < 0.001) and a negative correlation between higher Johnsen score and both ADC (p = 0.015) and MTR (p = 0.003) were found. TV (p < 0.001) was reduced in NOA testes with failed sperm retrieval compared with NOA testes with positive sperm retrieval. On the contrary, ADC (p = 0.011) and MTR (p = 0.045) were significantly increased in NOA testes with negative sperm retrieval. CONCLUSION. On the basis of our preliminary data, TV, ADC, and MTR might represent useful MRI parameters in the workup of patients with NOA by helping to predict the presence of spermatozoa after mTESE.


Assuntos
Azoospermia/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Recuperação Espermática , Adulto , Estudos de Casos e Controles , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
8.
Pediatr Radiol ; 49(8): 1078-1084, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31053875

RESUMO

BACKGROUND: Structural and functional changes of the brain have been reported in premature babies. OBJECTIVE: To evaluate the relationship of functional and structural connectivity with gestational age, body growth and brain maturation in very preterm babies. MATERIALS AND METHODS: We studied 18 very preterm babies (gestational age: mean ± standard deviation, 29.7±1.7 weeks). We examined functional connectivity by multivariate pattern analysis of resting-state functional MRI data. We assessed structural connectivity by analysis of diffusion tensor imaging data and probabilistic tractography. RESULTS: The average functional connectivity of the medial orbitofrontal cortex with the rest of the brain was positively associated with gestational age (P<0.001). Fractional anisotropy of the right inferior fronto-occipital fasciculus was positively associated with head circumference at term-equivalent age. Structural connectivity of the inferior fronto-occipital fasciculus with the medial orbitofrontal cortex was positively associated with head circumference at term-equivalent age. Body weight at term-equivalent age was the only independent predictor of average structural connectivity of the medial orbitofrontal cortex with the rest of the brain (P=0.020). CONCLUSION: Structural and functional connectivity of the medial orbitofrontal cortex with the rest of the brain depend on body growth and degree of prematurity, respectively.


Assuntos
Encéfalo/crescimento & desenvolvimento , Desenvolvimento Infantil/fisiologia , Imagem de Tensor de Difusão/métodos , Idade Gestacional , Lactente Extremamente Prematuro/crescimento & desenvolvimento , Vias Neurais/diagnóstico por imagem , Mapeamento Encefálico/métodos , Estudos de Coortes , Feminino , Humanos , Recém-Nascido , Valor Preditivo dos Testes , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/crescimento & desenvolvimento
9.
Andrologia ; 51(3): e13210, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30556169

RESUMO

A noninvasive imaging technique providing information about testicular dysfunction in testes with varicocele would be useful. The aim is to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in testes of infertile men with varicocele and to assess interobserver agreement. Sixteen infertile men with varicocele and 14 age-matched controls underwent 1.5 T diffusion tensor imaging (DTI) MRI. Testicular ADC and FA were measured by two radiologists independently. Parametric and nonparametric statistical tests were applied to compare between the ADC and FA of testes with varicocele and normal testes. Interobserver agreement was evaluated. The interobserver variability for ADC (0.915) and FA (0.948) was very good. No differences in ADC (p = 0.294) were found between the two groups. FA was significantly lower in testes with varicocele compared to age-matched controls (p < 0.001). An optimal cut-off of FA 0.08 was found for the diagnosis of varicocele (sensitivity = 88%, specificity = 93.5%, positive predictive value = 91.6% and negative predictive value = 90.6%). Based on our results, FA is useful for the diagnosis of testes in infertile men with varicocele, with very good interobserver agreement. Therefore, DTI may be used as a noninvasive imaging tool in the work-up of varicocele.


Assuntos
Infertilidade Masculina/diagnóstico por imagem , Testículo/diagnóstico por imagem , Varicocele/diagnóstico por imagem , Adulto , Anisotropia , Imagem de Tensor de Difusão , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
12.
Eur Radiol ; 26(7): 2261-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26474986

RESUMO

OBJECTIVES: The aim was to determine the proton MR (1H-MR) spectra of normal adult testes and variations with age. METHODS: Forty-one MR spectra of normal testes, including 16 testes from men aged 20-39 years (group I) and 25 testes from men aged 40-69 years (group II), were analyzed. A single-voxel point-resolved spectroscopy sequence (PRESS), with TR/TE: 2000/25 ms was used. The volume of interest was placed to include the majority of normal testicular parenchyma. Association between normalized metabolite concentrations, defined as ratios of the calculated metabolite concentrations relative to creatine concentration, and age was assessed. RESULTS: Quantified metabolites of the spectra were choline (Cho), creatine (Cr), myo-inositol (mI), scyllo-inositol, taurine, lactate, GLx compound, glucose, lipids, and macromolecules resonating at 0.9 ppm (LM09), around 20 ppm (LM20), and at 13 ppm (LM13). Most prominent peaks were Cho, Cr, mI, and lipids. A weak negative correlation between mI and age (P = 0.015) was observed. Higher normalized concentrations of Cho (P = 0.03), mI (P = 0.08), and LM13 (P = 0.05) were found in group I than in group II. CONCLUSIONS: 1H-MR spectra of a normal adult testis showed several metabolite peaks. A decrease of levels of Cho, mI, and LM13 was observed with advancing age. KEY POINTS: • Single-voxel PRESS MRS of a normal testis is feasible. • 1H-MR spectra of a normal testis showed several metabolite peaks. • Most prominent peaks were Cho, Cr, mI, and lipids. • A decrease of Cho, mI, and LM13 was seen with advancing age.


Assuntos
Envelhecimento , Espectroscopia de Ressonância Magnética/métodos , Testículo/anatomia & histologia , Testículo/metabolismo , Adulto , Fatores Etários , Idoso , Colina/metabolismo , Creatina/metabolismo , Humanos , Inositol/metabolismo , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Eur Radiol ; 26(3): 613-21, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26065397

RESUMO

OBJECTIVES: The aim was to determine the magnetization transfer ratio (MTR) of normal testes, possible variations with age and to assess the feasibility of MTR in characterizing various testicular lesions. METHODS: Eighty-six men were included. A three-dimensional gradient-echo MT sequence was performed, with/without an on-resonance binomial prepulse. MTR was calculated as: (SIo-SIm)/(SIo) × 100 %, where SIm and SIo refers to signal intensities with and without the saturation pulse, respectively. Subjects were classified as: group 1, 20-39 years; group 2, 40-65 years; and group 3, older than 65 years of age. Analysis of variance (ANOVA) followed by the least significant difference test was used to assess variations of MTR with age. Comparison between the MTR of normal testis, malignant and benign testicular lesions was performed using independent-samples t testing. RESULTS: ANOVA revealed differences of MTR between age groups (F = 7.51, P = 0.001). Significant differences between groups 1, 2 (P = 0.011) and 1, 3 (P < 0.001) were found, but not between 2, 3 (P = 0.082). The MTR (in percent) of testicular carcinomas was 55.0 ± 3.2, significantly higher than that of benign lesions (50.3 ± 4.0, P = 0.02) and of normal testes (47.4 ± 2.2, P < 0.001). CONCLUSIONS: MTR of normal testes decreases with age. MTR might be helpful in the diagnostic work-up of testicular lesions. KEY POINTS: MTR of normal testes shows age-related changes. Testicular carcinomas have high MTR values. MTR may be useful in the diagnostic work-up of testicular lesions.


Assuntos
Imageamento por Ressonância Magnética/métodos , Testículo/anatomia & histologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Epididimite/diagnóstico , Estudos de Viabilidade , Humanos , Imageamento Tridimensional/métodos , Imageamento Tridimensional/estatística & dados numéricos , Imageamento por Ressonância Magnética/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Neoplasias Embrionárias de Células Germinativas/diagnóstico , Orquite/diagnóstico , Doenças Testiculares/diagnóstico , Neoplasias Testiculares/diagnóstico , Adulto Jovem
14.
Pediatr Radiol ; 46(7): 941-51, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27233787

RESUMO

Magnetic resonance spectroscopy (MRS) provides independent biochemical information and has become an invaluable adjunct to MRI and other imaging modalities. This review introduces key concepts and presents basic methodological steps regarding the acquisition and the interpretation of proton MRS. We review major brain metabolites and discuss MRS dependence on age, location, echo time and field strength.


Assuntos
Encefalopatias/diagnóstico por imagem , Encefalopatias/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Espectroscopia de Prótons por Ressonância Magnética/métodos , Encéfalo/crescimento & desenvolvimento , Criança , Humanos
15.
Pediatr Radiol ; 46(8): 1158-64, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27085522

RESUMO

BACKGROUND: There is evidence of microstructural changes in normal-appearing white matter of patients with tuberous sclerosis complex. OBJECTIVE: To evaluate major white matter tracts in children with tuberous sclerosis complex using tract-based spatial statistics diffusion tensor imaging (DTI) analysis. MATERIALS AND METHODS: Eight children (mean age ± standard deviation: 8.5 ± 5.5 years) with an established diagnosis of tuberous sclerosis complex and 8 age-matched controls were studied. The imaging protocol consisted of T1-weighted high-resolution 3-D spoiled gradient-echo sequence and a spin-echo, echo-planar diffusion-weighted sequence. Differences in the diffusion indices were evaluated using tract-based spatial statistics. RESULTS: Tract-based spatial statistics showed increased axial diffusivity in the children with tuberous sclerosis complex in the superior and anterior corona radiata, the superior longitudinal fascicle, the inferior fronto-occipital fascicle, the uncinate fascicle and the anterior thalamic radiation. No significant differences were observed in fractional anisotropy, mean diffusivity and radial diffusivity between patients and control subjects. No difference was found in the diffusion indices between the baseline and follow-up examination in the patient group. CONCLUSION: Patients with tuberous sclerosis complex have increased axial diffusivity in major white matter tracts, probably related to reduced axonal integrity.


Assuntos
Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Esclerose Tuberosa/patologia , Substância Branca/patologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Esclerose Tuberosa/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
16.
Int J Neurosci ; 126(5): 422-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26000811

RESUMO

PURPOSE OF THE STUDY: The multimodal imaging investigation of excessive daytime sleepiness (EDS) in Parkinson's disease (PD). The role of dopaminergic treatment and other clinical parameters was also evaluated. MATERIALS AND METHODS: Seventeen non-demented PD patients with EDS (PD-EDS) and 17 PD patients without EDS were enrolled. Clinical, treatment and MRI data were acquired. Gray matter (GM) volume was examined with voxel-based morphometry, while white matter (WM) integrity was assessed with diffusion tensor imaging by means of fractional anisotropy, mean diffusivity, axial diffusivity (AD) and radial diffusivity measures. RESULTS: Increased regional GM volume was found in the PD-EDS group bilaterally in the hippocampus and parahippocampal gyri. Increased AD values were also shown in the PD-EDS group, in the left anterior thalamic radiation and the corticospinal tract and bilaterally in the superior corona radiata and the superior longitudinal fasciculus. Levodopa equivalent dose differed significantly between the groups and was the only predictor of EDS, while the only predictor of the Epworth sleepiness scale score in the PD-EDS group was the dopamine-agonist dose. Increased frequency of gamblers was also observed in the PD-EDS group. CONCLUSIONS: Regional GM increases and increased AD values in certain WM tracts were found in the PD-EDS group. The changes could result from disinhibited signaling pathways or represent compensatory changes in response to anatomical or functional deficits elsewhere. The study findings support also the contribution of the total dopaminergic load in the development of EDS, while the dose of dopamine agonists was found to predict the severity of the disorder.


Assuntos
Encéfalo/fisiopatologia , Distúrbios do Sono por Sonolência Excessiva/complicações , Doença de Parkinson/complicações , Idoso , Encéfalo/patologia , Imagem de Tensor de Difusão , Distúrbios do Sono por Sonolência Excessiva/patologia , Distúrbios do Sono por Sonolência Excessiva/fisiopatologia , Feminino , Substância Cinzenta/patologia , Substância Cinzenta/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Doença de Parkinson/patologia , Doença de Parkinson/fisiopatologia , Substância Branca/patologia , Substância Branca/fisiopatologia
17.
Electromagn Biol Med ; 34(4): 361-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25006865

RESUMO

The electric field effects on conformational properties of trialanine in different halide solutions were explored with long-scale molecular dynamics simulations. NaF, NaCl, NaBr and NaI solutions of low (0.2 M) and high (2 M) concentrations were exposed to a constant electric field of 1000 V/m. Generally, the electric field does not disturb trialanine's structure. Large structural changes appear only in the case of the supersaturated 2.0 M NaF solution containing NaF crystals. Although the electric field affects in a complex way, all the ions-water-peptide interactions, it predominantly affects the electroselectivity effect, which describes specific interactions such as the ion-pair formation.


Assuntos
Brometos/química , Campos Eletromagnéticos , Oligopeptídeos/química , Cloreto de Sódio/química , Compostos de Sódio/química , Fluoreto de Sódio/química , Iodeto de Sódio/química , Halogênios/química , Íons , Simulação de Dinâmica Molecular , Software , Soluções , Água/química
18.
Eur Radiol ; 24(10): 2499-506, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25001084

RESUMO

OBJECTIVES: To investigate structural brain changes in inflammatory bowel disease (IBD). METHODS: Brain magnetic resonance imaging (MRI) was performed on 18 IBD patients (aged 45.16 ± 14.71 years) and 20 aged-matched control subjects. The imaging protocol consisted of a sagittal-FLAIR, a T1-weighted high-resolution three-dimensional spoiled gradient-echo sequence, and a multisession spin-echo echo-planar diffusion-weighted sequence. Differences between patients and controls in brain volume and diffusion indices were evaluated using the voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) methods, respectively. The presence of white-matter hyperintensities (WMHIs) was evaluated on FLAIR images. RESULTS: VBM revealed decreased grey matter (GM) volume in patients in the fusiform and the inferior temporal gyrus bilaterally, the right precentral gyrus, the right supplementary motor area, the right middle frontal gyrus and the left superior parietal gyrus (p < 0.05). TBSS showed decreased axial diffusivity (AD) in the right corticospinal tract and the right superior longitudinal fasciculus in patients compared with controls. A larger number of WMHIs was observed in patients (p < 0.05). CONCLUSIONS: Patients with IBD show an increase in WMHIs and GM atrophy, probably related to cerebral vasculitis and ischaemia. Decreased AD in major white matter tracts could be a secondary phenomenon, representing Wallerian degeneration. KEY POINTS: • There is evidence of central nervous system involvement in IBD. • Diffusion tensor imaging detects microstructural brain abnormalities in IBD. • Voxel based morphometry reveals brain atrophy in IBD.


Assuntos
Encefalopatias/diagnóstico , Encéfalo/patologia , Imagem de Tensor de Difusão/métodos , Doenças Inflamatórias Intestinais/complicações , Imageamento por Ressonância Magnética/métodos , Atrofia/diagnóstico , Atrofia/etiologia , Encefalopatias/etiologia , Tronco Encefálico/patologia , Feminino , Seguimentos , Lobo Frontal/patologia , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Masculino , Pessoa de Meia-Idade , Lobo Parietal/patologia , Tratos Piramidais/patologia , Curva ROC , Lobo Temporal/patologia , Substância Branca/patologia
19.
Pediatr Radiol ; 44(3): 297-304, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24190757

RESUMO

BACKGROUND: Prematurity and intrauterine growth restriction are associated with neurodevelopmental disabilities. OBJECTIVE: To assess the relationship between growth status and regional brain volume (rBV) and white matter microstructure in premature babies at around term-equivalent age. MATERIALS AND METHODS: Premature infants (n= 27) of gestational age (GA): 29.8 ± 2.1 weeks, with normal brain MRI scans were studied at corrected age: 41.2 ± 1.4 weeks. The infants were divided into three groups: 1) appropriate for GA at birth and at the time of MRI (AGA), 2) small for GA at birth with catch-up growth at the time of MRI (SGAa) and 3) small for GA at birth with failure of catch-up growth at the time of MRI (SGAb). The T1-weighted images were segmented into 90 rBVs using the SPM8/IBASPM and differences among groups were assessed. Fractional anisotropy (FA) was measured bilaterally in 15 fiber tracts and its relationship to GA and somatometric measurements was explored. RESULTS: Lower rBV was observed in SGAb in superior and anterior brain areas. A positive correlation was demonstrated between FA and head circumference and body weight. Body weight was the only significant predictor for FA (P< 0.05). CONCLUSION: In premature babies, catch-up growth is associated with regional brain volume catch-up at around term-equivalent age, starting from the brain areas maturing first. Body weight seems to be a strong predictor associated with WM microstructure in brain areas related to attention, language, cognition, memory and executing functioning.


Assuntos
Tamanho Corporal/fisiologia , Encéfalo/anatomia & histologia , Encéfalo/crescimento & desenvolvimento , Recém-Nascido Prematuro/crescimento & desenvolvimento , Recém-Nascido Pequeno para a Idade Gestacional/crescimento & desenvolvimento , Imageamento por Ressonância Magnética/métodos , Feminino , Humanos , Recém-Nascido , Masculino , Tamanho do Órgão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Curr Oncol ; 31(4): 2233-2243, 2024 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-38668068

RESUMO

Background: Extracting multiregional radiomic features from multiparametric MRI for predicting pretreatment survival in isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM) patients is a promising approach. Methods: MRI data from 49 IDH wild-type glioblastoma patients pre-treatment were utilized. Diffusion and perfusion maps were generated, and tumor subregions segmented. Radiomic features were extracted for each tissue type and map. Feature selection on 1862 radiomic features identified 25 significant features. The Cox proportional-hazards model with LASSO regularization was used to perform survival analysis. Internal and external validation used a 38-patient training cohort and an 11-patient validation cohort. Statistical significance was set at p < 0.05. Results: Age and six radiomic features (shape and first and second order) from T1W, diffusion, and perfusion maps contributed to the final model. Findings suggest that a small necrotic subregion, inhomogeneous vascularization in the solid non-enhancing subregion, and edema-related tissue damage in the enhancing and edema subregions are linked to poor survival. The model's C-Index was 0.66 (95% C.I. 0.54-0.80). External validation demonstrated good accuracy (AUC > 0.65) at all time points. Conclusions: Radiomics analysis, utilizing segmented perfusion and diffusion maps, provide predictive indicators of survival in IDH wild-type glioblastoma patients, revealing associations with microstructural and vascular heterogeneity in the tumor.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Imageamento por Ressonância Magnética , Humanos , Glioblastoma/diagnóstico por imagem , Glioblastoma/mortalidade , Feminino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Masculino , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/mortalidade , Idoso , Adulto , Análise de Sobrevida , Prognóstico , Radiômica
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