Evaluation of Subcortical Structure Volumes in Patients with Non-Specific Digestive Diseases.

(1) Background: To evaluate volume of subcortical structures such as hippocampus, globus pallidus, putamen, thalamus, nucleus accumbens, amygdala, caudate in patients with non-specific digestive diseases (functional dyspepsia-FD, irritable bowel syndrome-IBS) and non-specific inflammatory bowel diseases-IBD (colitis ulcerosa and Crohn's disease) in comparison to healthy control group (CON). (2) Material: The analysis included data obtained from 57 patients (FD-18, IBS-20, IBD-19) and 19 persons in control group. Both groups underwent examination in a 3T scanner (Achieva TX Philips Healthcare). (3) Results: Significant differences between the IBD group and Control group in volume of left thalamus and IBD group vs Control group in volume of right thalamus. (4) Conclusions: The brain-gut axis hypothesis explains connection between biological behavior, emotions and cognitive functions in patients with gastrointestinal disease. We found that there is a difference between volume of thalamus in IBD patients in comparison to both IBS and control group and it occurred to be smaller. Excess inflammation can be linked with psychological disorders like depressive symptoms, sleep difficulties and/or fatigue. Therefore, there is a need for using treatment both for depressive symptoms and IBD to reduce the causes and effects of inflammation.

Morphometric evaluations based on Voxel Based Morphometry on adolescents with autism spectrum disorders. / Badania morfometryczne oparte o pomiar voksela (Voxel Based Morphometry) u nastolatków z zaburzeniami ze spektrum autyzmu.

OBJECTIVES: Goal: to evaluate changes in the grey matter volume using the VBM method in a group of adolescents with ASD, who met the criteria for Asperger's Syndrome. METHODS: Material and methods: Morphometric evaluations based on Voxel Based Morphometry (VBM) were performed on 37 male adolescents aged 12 to 19 (M = 14.3 ± 2.0), with autism spectrum disorders, who met the DSM-IV-TR criteria for Asperger's Syndrome and 15 neurotypical adolescents matched by age. Significance was set at p<0.007 without FWE correction and p<0.05 with FWE correction. RESULTS: Results: the decrease in the volume of the grey matter was observed in ASD group including the pre- and postcentral gyrus, the superior and middle frontal gyrus, the inferior and superior parietal lobule, the praecuneus, the anterior and posterior cingulate cortex, the fusiform gyrus, the parahippocampal gyrus, the lingual gyrus, the middle occipital region, the cuneus and the angular gyrus, the regions of calcarine sulcus and the cerebellum. The majority of changes was localized bilaterally. CONCLUSIONS: Conclusions: the decrease in the volume of grey matter observed in ASD group can be related functionally with the characteristics of deficits observed in autism spectrum disorders which highlights the role of abnormal organization of numerous CNS structures in the genesis of symptoms observed in cognitive and behavioural domains.

Semantic decisions in adolescents with autism spectrum disorders - functional magnetic resonance imaging study. / Decyzje semantyczne u nastolatków z zaburzeniami ze spektrum autyzmu - badanie czynnosciowym rezonansem magnetycznym.

OBJECTIVES: Goal: to assess fMRI activation during semantic tasks in adolescents with ASD. METHODS: Material: 44 right-handed male adolescents aged 12-19 (mean 14.3 ± 2.0) - 31 with autism spectrum disorders who met DSM-IV-TR criteria for Asperger's syndrome and 13 neurotypical adolescents matched according to age and handiness. Method: Functional testing (fMRI) was performed during semantic decisions tasks and phonological decisions in three categories of tasks: concrete nouns, verbs with plural meanings, words describing states of mind, as a control condition. Statistical analyzes were performed at the level of p <0.05 with FWE (family-wise error) correction and p <0.001. RESULTS: Results: lower BOLD signal was demonstrated in many brain areas including precuneus, posterior cingulate gyrus, angular gyrus, parahippocampal gyrus, regardless of task category and processing method in the ASD group. The smallest differences in semantic processing were found for concrete nouns and the greatest ones for words describing states of mind. CONCLUSIONS: Conclusions: the presence of different activation patterns in the ASD group suggests that far more than just the areas traditionally attributed to language processing, are involved in semantic deficits in ASD.

Imaging of Morphological Background in Selected Functional and Inflammatory Gastrointestinal Diseases in fMRI.

The study focuses on evaluation of the Default Mode Network (DMN) activity in functional magnetic resonance imaging (fMRI) in resting state in patients with functional dyspepsia (FD) and irritable bowel syndrome (IBS), Crohn's disease and colitis ulcerosa (IBD) in comparison to healthy volunteers. We assume that etiology of both functional and non-specific inflammatory bowel diseases is correlated with disrupted structure of axonal connections. We would like to identify the network of neuronal connections responsible for presentation of symptoms in these diseases. 56 patients (functional dyspepsia, 18; Crohn's disease and colitis ulcerosa, 18; irritable bowel syndrome, 20) and 18 healthy volunteers underwent examination in MRI of the brain with assessment of brain morphology and central nervous system activity in functional imaging in resting state performed in 3T scanner. Compared to healthy controls' DMN in patients with non-specific digestive tract diseases comprised additional areas in superior frontal gyrus of left hemisphere, in left cingulum and in the left supplementary motor area. Discovered differences in the DMNs can be interpreted as altered processing of homeostatic stimuli. Our study group involved patients suffering from both functional and non-specific inflammatory bowel diseases. Nevertheless a spectrum of changes in the study group (superior frontal gyrus of the left hemisphere, in the left cingulum and in the left supplementary motor area) we were able to find common features, differentiating the whole study group from the healthy controls.

Use of functional magnetic resonance imaging in patients with irritable bowel syndrome and functional dyspepsia.

Functional brain imaging (positron emission tomography - PET, functional magnetic resonance imaging - fMRI), allowing in vivo analysis of the brain-digestive tract interaction and the neurological mechanisms underlying visceral hypersensitivity, significantly advanced research and helped in the understanding of the interrelations in this field. Differences in this parameter can result from alterations in task-related cognitive states or from resting state processes. Nowadays, advanced imaging techniques such as fMRI are more frequently used and are acknowledged among both clinicians and radiologists in the diagnostic algorithm of digestive tract diseases. Functional dyspepsia is a condition in which neuroimaging allows for analysis of dysfunctions within the brain-gut axis (BGA) engaged in processing of visceral discomfort and pain. The results of studies in patient groups with irritable bowel syndrome prove that psychosocial factors significantly affect the mechanisms regulating visceral sensitivity within the brain. The BGA includes neuronal pathways (autonomic nervous system), neuroendocrine (hypothalamo-pituitary-adrenal axis), and neuroimmunological ones. Psychological processes affect the functioning of the digestive system and can cause dyspeptic symptoms. A patient's mental condition associated with stress can affect processes taking place in the central nervous system and trigger somatic reactions in the digestive tract through the autonomic visceral system.

Aging and Hypertension - Independent or Intertwined White Matter Impairing Factors? Insights From the Quantitative Diffusion Tensor Imaging.

Aging disrupts white matter integrity, and so does continuous elevated blood pressure that accompanies hypertension (HTN). Yet, our understanding of the interrelationship between these factors is still limited. The study aimed at evaluating patterns of changes in diffusion parameters (as assessed by quantitative diffusion fiber tracking - qDTI) following both aging, and hypertension, as well as the nature of their linkage. 146 participants took part in the study: the control group (N = 61) and the patients with hypertension (N = 85), and were divided into three age subgroups (25-47, 48-56, 57-71 years). qDTI was used to calculate the values of fractional anisotropy, mean, radial and axial diffusivity in 20 main tracts of the brain. The effects of factors (aging and hypertension) on diffusion parameters of tracts were tested with a two-way ANOVA. In the right hemisphere there was no clear effect of the HTN, nor an interaction between the factors, though some age-related effects were observed. Contrary, in the left hemisphere both aging and hypertension contributed to the white matter decline, following a functional pattern. In the projection pathways and the fornix, HTN and aging played part independent of each other, whereas in association fibers and the corpus callosum if the hypertension effect was significant, an interaction was observed. HTN patients manifested faster decline of diffusion parameters but also reached a plateau earlier, with highest between-group differences noted in the middle-aged subgroup. Healthy and hypertensive participants have different brain aging patterns. The HTN is associated with acceleration of white matter integrity decline, observed mainly in association fibers of the left hemisphere.

Cognitive Predictors of Cortical Thickness in Healthy Aging.

This study seeks to define the role of predictive values of the motor speed, inhibition control, and fluid and crystallized intelligence in estimating the cortical thickness in healthy elderly. Forty-six older healthy subjects (37 women, 9 men) over 60 years of age were included in the study. The participants were examined on 3.0 T MRI scanners. The protocol included standard anatomical sequences, to exclude brain pathology, and a high-resolution T1-weighted sequence used to estimate the cortical thickness. The neuropsychological protocol included fluid intelligence assessment (Raven Progressive Matrices), crystalized intelligence assessment (information or vocabulary subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R)), and executive functioning (Color Traits Test). The findings unraveled several interdependencies. The higher the intelligence, the thicker was the grey matter in nine regions of both hemispheres, but also some paradoxical reversed associations were found in four areas; all of them were localized along different sections of the cingulate gyrus in both hemispheres. An inverse association was found between crystallized intelligence and the thickness of the pars opecularis of the right hemisphere. The better the executive functioning, the thicker was the grey matter of a given region. The better the motor performance, the thicker was the grey matter of the rostral middle frontal area of the left hemisphere and the lingual gyrus of both hemispheres. In conclusion, the associations unraveled demonstrate that the neural mechanisms underlying healthy aging are complex and heterogenic across different cognitive domains and neuroanatomical regions. No brain aging theory seems to provide a suitable interpretative framework for all the results. A novel, more integrative approach to the brain aging should be considered.

Understanding the Physiopathology Behind Axial and Radial Diffusivity Changes-What Do We Know?

The use of the diffusion tensor imaging (DTI) is rapidly growing in the neuroimaging field. Nevertheless, rigorously performed quantitative validation of DTI pathologic metrics remains very limited owing to the difficulty in co-registering quantitative histology findings with magnetic resonance imaging. The aim of this review is to summarize the existing state-of-the-art knowledge with respect to axial (λ║) and radial (λ┴) diffusivity as DTI markers of axonal and myelin damage, respectively. First, we provide technical background for DTI and briefly discuss the specific organization of white matter in bundles of axonal fibers running in parallel; this is the natural target for imaging based on diffusion anisotropy. Second, we discuss the four seminal studies that paved the way for considering axial (λ║) and radial (λ┴) diffusivity as potential in vivo surrogate markers of axonal and myelin damage, respectively. Then, we present difficulties in interpreting axial (λ║) and radial (λ┴) diffusivity in clinical conditions associated with inflammation, edema, and white matter fiber crossing. Finally, future directions are highlighted. In summary, DTI can reveal strategic information with respect to white matter tracts, disconnection mechanisms, and related symptoms. Axial (λ║) and radial (λ┴) diffusivity seem to provide quite consistent information in healthy subjects, and in pathological conditions with limited edema and inflammatory changes. DTI remains one of the most promising non-invasive diagnostic tools in medicine.

Compensatory functional reorganization may precede hypertension-related brain damage and cognitive decline: a functional magnetic resonance imaging study.

OBJECTIVES: Our study aimed at exploring structural and functional differences in the brain during higher cognitive processing between middle-aged hypertensive patients and controls matched for sex, age and years of education. METHODS: Two groups of 20 patients took part in MRI examinations. This article reports the results of functional MRI during a Stroop color interference task and structural evaluations based on a modified Fazekas scale. RESULTS: No intergroup differences were found in regards to the severity of white matter lesions (Mann-Whitney U test = 150.5, P > 0.1), nor from the task performance in the scanner (t(35) = 0.2, P > 0.1). However, brain activation patterns between patients and controls varied. Hypertensive patients involved significantly more cerebral areas during the processing, regardless of the task difficulty. Differences were found in 26 diverse regions of both primary and associative cortices (with a peak voxel located in the cuneus, Z = 6.94, P < 0.05 family-wise error corrected at voxel level). CONCLUSION: Our findings provide an insight into the brain mechanisms related to essential hypertension and suggest a functional reorganization (neuroplasticity) early in the course of the disease.

Usefulness of computed tomography virtual bronchoscopy in the evaluation of bronchi divisions.

BACKGROUND: Since introduction of multislice CT scanners into clinical practice, virtual brochoscopy has gained a lot of quality and diagnostic potential. Nevertheless it does not have established place in diagnostics of tracheal and bronchi disorders and its potential has not been examined enough. Nowadays a majority of bronchial tree variants and lesions are revealed by bronchofiberoscopy, which is an objective and a relatively safe method, but has side effects, especially in higher-risk subjects. Therefore noninvasive techniques enabling evaluation of airways should be consistently developed and updated. MATERIAL/METHODS: Material consisted of 100 adults (45 female, 55 male) aged between 18 and 65 years (mean 40 years, median 40.5 years, SD 14.02), who underwent chest CT examination by means of a 16-slice scanner. Every patient had normal appearance of chest organs, with the exception of minor abnormalities that did not alter airways route. Divisions of bronchial tree to segmental level were evaluated and assigned to particular types by means of virtual bronchoscopy projection. In case of difficulties MPR or MinIP projection was used. RESULTS: THE FREQUENCY OF LOBAR BRONCHI DIVISIONS OTHER THAN THE TYPICAL ONES WAS IN: right upper lobar bronchi 45%, left 55%; middle lobar bronchi 21%, lingula 26%; right lower lobar bronchi 28%, left 29%. Subsuperior bronchus or bronchi were found on the right side in 44% and on the left side in 37%. No dependency between types of bronchial divisions on different levels was found.

[Application of simultaneous auditory evoked potentials and functional magnetic resonance recordings for examination of central auditory system--preliminary results]. / Wykorzystanie jednoczesnych rejestracji sluchowych potencjalów korowych i funkcjonalnego rezonansu magnetycznego do badania procesów osrodkowej czesci ukladu sluchowego--wyniki wstepne.

INTRODUCTION: Processing of auditory information in central nervous system bases on the series of quickly occurring neural processes that cannot be separately monitored using only the fMRI registration. Simultaneous recording of the auditory evoked potentials, characterized by good temporal resolution, and the functional magnetic resonance imaging with excellent spatial resolution allows studying higher auditory functions with precision both in time and space. THE AIM OF THE STUDY: was to implement the simultaneous AEP-fMRI recordings method for the investigation of information processing at different levels of central auditory system. MATERIAL AND METHODS: Five healthy volunteers, aged 22-35 years, participated in the experiment. The study was performed using high-field (3T) MR scanner from Siemens and 64-channel electrophysiological system Neuroscan from Compumedics. Auditory evoked potentials generated by acoustic stimuli (standard and deviant tones) were registered using modified odd-ball procedure. Functional magnetic resonance recordings were performed using sparse acquisition paradigm. The results of electrophysiological registrations have been worked out by determining voltage distributions of AEP on skull and modeling their bioelectrical intracerebral generators (dipoles). FMRI activations were determined on the basis of deviant to standard and standard to deviant functional contrasts. Results obtained from electrophysiological studies have been integrated with functional outcomes. RESULTS: Morphology, amplitude, latency and voltage distribution of auditory evoked potentials (P1, N1, P2) to standard stimuli presented during simultaneous AEP-fMRI registrations were very similar to the responses obtained outside scanner room. Significant fMRI activations to standard stimuli were found mainly in the auditory cortex. Activations in these regions corresponded with N1 wave dipoles modeled based on auditory potentials generated by standard tones. Auditory evoked potentials to deviant stimuli were recorded only outside the MRI scanner. However, deviant stimuli induced significant fMRI activations. They were observed mainly in the anterior cingulate gyrus, insula and parietal lobes. These regions of the brain are related to attention and decision-making processes. CONCLUSIONS: The results showed that applied paradigm is suitable for investigation of acoustic processing on the level of auditory cortex. Technique of the simultaneous AEP-fMRI registrations seems to be promising for investigation of more complex nervous processes in central auditory system with good temporo-spatial resolution.