Survival Outcome Prediction in Glioblastoma: Insights from MRI Radiomics.

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.

Pituitary gland height evaluated with magnetic resonance imaging in premature twins: the impact of growth and sex.

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.

The role of ventral tegmental area in chronic stroke rehabilitation: an exploratory study.

Introduction: The acknowledged role of external rewards in chronic stroke rehabilitation, offering positive reinforcement and motivation, has significantly contributed to patient engagement and perseverance. However, the exploration of self-reward's importance in this context remains limited. This study aims to investigate the functional connectivity of the ventral tegmental area (VTA), a key node in the brain's reward circuitry, during motor task-based rehabilitation and its correlation with the recovery process. Methods: Twelve right-handed healthy volunteers (4 men, 8 women, aged 57.4 ± 11.3 years) and twelve chronic stroke patients (5 men, 7 women, aged 48.1 ± 11.1 years) with clinically significant right-sided motor impairment (mean FM-UE score of 27.6 ± 8.7) participated. The analysis employed the CONN toolbox to assess the association between motor tasks and VTA connectivity using psychophysiological interaction (PPI). Results: PPI analysis revealed motor-dependent changes in VTA connectivity, particularly with regions within the motor circuitry, cerebellum, and prefrontal cortex. Notably, stronger connectivity between the ipsilesional VTA and cerebellum was observed in healthy controls compared to chronic stroke patients, highlighting the importance of VTA-cerebellum interactions in motor function. Stroke patients' motor performance was associated with VTA modulation in areas related to both motor tasks and reward processing, emphasizing the role of self-reward processes in rehabilitation. Changes in VTA influence on motor circuitry were linked to improvements in motor performance resulting from rehabilitation. Discussion: Our findings underscore the potential of neuroimaging techniques in quantifying and predicting rehabilitation outcomes by examining self-reward processes. The observed associations between VTA connectivity and motor performance in both healthy and stroke-affected individuals emphasize the role of psychological factors, particularly self-reward, in the rehabilitation process. This study contributes valuable insights into the intricate interplay between reward circuits and motor function, highlighting the importance of addressing psychological dimensions in neurorehabilitation strategies.

The Severity of Sensorimotor Tracts Degeneration May Predict Motor Performance in Chronic Stroke Patients, While Brain Structural Network Dysfunction May Not.

Although the relationship between corticospinal tract (CST) fiber degeneration and motor outcome after stroke has been established, the relationship of sensorimotor cortical areas with CST fibers has not been clarified. Also limited research has been conducted on how abnormalities in brain structural networks are related to motor recovery. To address these gaps in knowledge, we conducted a diffusion tensor imaging (DTI) study with 12 chronic stroke patients (CSPs) and 12 age-matched healthy controls (HCs). We compared fractional anisotropy (FA) and mean diffusivity (MD) in 60 CST segments using the probabilistic sensorimotor area tract template (SMATT). Least Absolute Shrinkage and Selection Operator (LASSO) regressions were used to select independent predictors of Fugl-Meyer upper extremity (FM-UE) scores among FA and MD values of SMATT regions. The Graph Theoretical Network Analysis Toolbox was used to assess the structural network of each subject's brain. Global and nodal metrics were calculated, compared between the groups, and correlated with FM-UE scores. Mann-Whitney U-tests revealed reduced FA values in CSPs, compared to HCs, in many ipsilesional SMATT regions and in two contralesional regions. Mean FA value of the left (L.) primary motor cortex (M1)/supplementary motor area (SMA) region was predictive of FM-UE score (P = 0.004). Mean MD values for the L. M1/ventral premotor cortex (PMv) region (P = 0.001) and L. PMv/SMA region (P = 0.001) were found to be significant predictors of FM-UE scores. Network efficiency was the only global metric found to be reduced in CSPs (P = 0.006 vs. HCs). Nodal efficiency of the L. hippocampus, L. parahippocampal gyrus, L. fusiform gyrus (P = 0.001), and nodal local efficiency of the L. supramarginal gyrus (P < 0.001) were reduced in CSPs relative to HCs. No graph metric was associated with FM-UE scores. In conclusion, the integrity of CSTs connected to M1, SMA, and PMv were shown to be independent predictors of motor performance in CSPs, while stroke-induced topological changes in the brain's structural connectome may not be. A sensorimotor cortex-specific tract template can refine CST degeneration data and the relationship of CST degeneration with motor performance.

Volumetric apparent diffusion coefficient histogram analysis of the testes in nonobstructive azoospermia: a noninvasive fingerprint of impaired spermatogenesis?

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.

Structural and functional brain connectivity in moderate-late preterm infants with low-grade intraventricular hemorrhage.

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.

Peak Activation Shifts in the Sensorimotor Cortex of Chronic Stroke Patients Following Robot-assisted Rehabilitation Therapy.

BACKGROUND: Ischemic stroke is the most common cause of complex chronic disability and the third leading cause of death worldwide. In recovering stroke patients, peak activation within the ipsilesional primary motor cortex (M1) during the performance of a simple motor task has been shown to exhibit an anterior shift in many studies and a posterior shift in other studies. OBJECTIVE: We investigated this discrepancy in chronic stroke patients who completed a robot-assisted rehabilitation therapy program. METHODS: Eight chronic stroke patients with an intact M1 and 13 Healthy Control (HC) volunteers underwent 300 functional magnetic resonance imaging (fMRI) scans while performing a grip task at different force levels with a robotic device. The patients were trained with the same robotic device over a 10-week intervention period and their progress was evaluated serially with the Fugl-Meyer and Modified Ashworth scales. Repeated measure analyses were used to assess group differences in locations of peak activity in the sensorimotor cortex (SM) and the relationship of such changes with scores on the Fugl-Meyer Upper Extremity (FM UE) scale. RESULTS: Patients moving their stroke-affected hand had proportionally more peak activations in the primary motor area and fewer peak activations in the somatosensory cortex than the healthy controls (P=0.009). They also showed an anterior shift of peak activity on average of 5.3-mm (P<0.001). The shift correlated negatively with FM UE scores (P=0.002). CONCLUSION: A stroke rehabilitation grip task with a robotic device was confirmed to be feasible during fMRI scanning and thus amenable to be used to assess plastic changes in neurological motor activity. Location of peak activity in the SM is a promising clinical neuroimaging index for the evaluation and monitoring of chronic stroke patients.

Improving motor function after chronic stroke by interactive gaming with a redesigned MR-compatible hand training device.

New rehabilitation strategies enabled by technological developments are challenging the prevailing concept of there being a limited window for functional recovery after stroke. In this study, we examined the utility of a robot-assisted therapy used in combination with a serious game as a rehabilitation and motor assessment tool in patients with chronic stroke. We evaluated 928 game rounds from 386 training sessions of 8 patients who had suffered an ischemic stroke affecting middle cerebral artery territory that incurred at least 6 months prior. Motor function was assessed with clinical motor scales, including the Fugl-Meyer upper extremity (FM UE) scale, Action Research Arm Test, Modified Ashworth scale and the Box and Blocks test. Robotic device output measures (mean force, force-position correlation) and serious game score elements (collisions, rewards and total score) were calculated. A total of 2 patients exhibited a marginal improvement after a 10-week training protocol according to the FM UE scale and an additional patient exhibited a significant improvement according to Box and Blocks test. Motor scales showed strong associations of robotic device parameters and game metrics with clinical motor scale scores, with the strongest correlations observed for the mean force (0.677<Ρ<0.869), followed by the number of collisions (-0.670<Ρ<-0.585). Linear regression analysis showed that these indices were independent predictors of motor scale scores. In conclusion, a robotic device linked to a serious game can be used by patients with chronic stroke and induce at least some clinical improvements in motor performance. Robotic device output parameters and game score elements associate strongly with clinical motor scales and have the potential to be used as predictors in models of rehabilitation progress.

Machine Learning Algorithms and Statistical Approaches for Alzheimer's Disease Analysis Based on Resting-State EEG Recordings: A Systematic Review.

Alzheimer's Disease (AD) is a neurodegenerative disorder and the most common type of dementia with a great prevalence in western countries. The diagnosis of AD and its progression is performed through a variety of clinical procedures including neuropsychological and physical examination, Electroencephalographic (EEG) recording, brain imaging and blood analysis. During the last decades, analysis of the electrophysiological dynamics in AD patients has gained great research interest, as an alternative and cost-effective approach. This paper summarizes recent publications focusing on (a) AD detection and (b) the correlation of quantitative EEG features with AD progression, as it is estimated by Mini Mental State Examination (MMSE) score. A total of 49 experimental studies published from 2009 until 2020, which apply machine learning algorithms on resting state EEG recordings from AD patients, are reviewed. Results of each experimental study are presented and compared. The majority of the studies focus on AD detection incorporating Support Vector Machines, while deep learning techniques have not yet been applied on large EEG datasets. Promising conclusions for future studies are presented.

Functional connectivity and microstructural changes of the brain in primary Sjögren syndrome: the relationship with depression.

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.

Are there differences in the biochemical profile of bilateral normal testes? A 3.0 T 1H-MR spectroscopy study.

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.

Pediatric minor head injury imaging practices: results from an ESPR survey.

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.

Testicular Apparent Diffusion Coefficient and Magnetization Transfer Ratio: Can These MRI Parameters Be Used to Predict Successful Sperm Retrieval in Nonobstructive Azoospermia?

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.

Functional and structural connectivity of the brain in very preterm babies: relationship with gestational age and body and brain growth.

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.

EEG Window Length Evaluation for the Detection of Alzheimer's Disease over Different Brain Regions.

Alzheimer's Disease (AD) is a neurogenerative disorder and the most common type of dementia with a rapidly increasing world prevalence. In this paper, the ability of several statistical and spectral features to detect AD from electroencephalographic (EEG) recordings is evaluated. For this purpose, clinical EEG recordings from 14 patients with AD (8 with mild AD and 6 with moderate AD) and 10 healthy, age-matched individuals are analyzed. The EEG signals are initially segmented in nonoverlapping epochs of different lengths ranging from 5 s to 12 s. Then, a group of statistical and spectral features calculated for each EEG rhythm (δ, θ, α, ß, and γ) are extracted, forming the feature vector that trained and tested a Random Forests classifier. Six classification problems are addressed, including the discrimination from whole-brain dynamics and separately from specific brain regions in order to highlight any alterations of the cortical regions. The results indicated a high accuracy ranging from 88.79% to 96.78% for whole-brain classification. Also, the classification accuracy was higher at the posterior and central regions than at the frontal area and the right side of temporal lobe for all classification problems.

Multifocal alterations of white matter accompany the transition from normal cognition to dementia in Parkinson's disease patients.

The purpose of the present study was to investigate the pattern of white matter (WM) changes associated with Parkinson's disease (PD)-related cognitive impairment by using fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) measures. Diffusion Tensor Imaging (DTI) was performed in 21 PD-patients with dementia (PDD) and in an age-matched control group including 40 PD-patients without dementia (PD-CTRL). The Parkinson's disease-Cognitive Rating Scale (PD-CRS) was used for patients' neuropsychological assessment. Local microstructural WM differences associated with the presence of cognitive impairment were tested using tract-based spatial statistics analysis. Multiple regression models investigated the association of DTI indices with total PD-CRS score, PD-CRS raw items and other clinical measures across the whole study sample. Significant FA decreases were found in PDD compared to PD-CTRL patients mainly in the body of corpus callosum, corona radiata and cingulum. Lower PD-CRS score was significantly associated with decreased FA, MD and AD values in multiple WM tracts primarily located in prefrontal and limbic areas as well as across the corpus callosum. Lower performance in specific PD-CRS raw items was also associated with FA decreases in major WM tracts. The results suggest that multifocal microstructural changes of WM accompany the transition from normal to demented cognitive state in PD-patients. The corpus callosum, the corona radiata and the cingulum are among the regions mostly affected during this course. A progressive axonal degeneration is proposed as a key underlying mechanism.

Diffusion tensor imaging as an adjunct tool for the diagnosis of varicocele.

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.

Brain activation during repeated imagining of chocolate consumption: a functional magnetic resonance imaging study.

OBJECTIVE: To assess brain activation during mental visualization of eating chocolate. DESIGN: Twenty-one subjects were included. FMRI was acquired with a single-shot, multislice, gradient echo-planar sequence, while subjects were performing two specific imaginary tasks. RESULTS: Activation of motor-associated brain areas was observed during both mental visualization tasks. Increased activation of the right dorsolateral prefrontal cortex, the thalamus, the postcentral gyrus and the left anterior cingulate cortex, and the precuneus was observed during imagining eating chocolate. CONCLUSIONS: Repeated imagination of chocolate consumption results in activation of brain areas associated with hedonic effects of food and satiety and inhibition of orexigenic areas.