Kurtosis analysis of neural diffusion organization

A computational framework is presented for relating the kurtosis tensor for water diffusion in brain to tissue models of brain microstructure. The tissue models are assumed to be comprised of non-exchanging compartments that may be associated with various microstructural spaces separated by cell membranes. Within each compartment the water diffusion is regarded as Gaussian, although the diffusion for the full system would typically be non-Gaussian. The model parameters are determined so as to minimize the Frobenius norm of the difference between the measured kurtosis tensor and the model kurtosis tensor. This framework, referred to as kurtosis analysis of neural diffusion organization (KANDO), may be used to help provide a biophysical interpretation to the information provided by the kurtosis tensor. In addition, KANDO combined with diffusional kurtosis imaging can furnish a practical approach for developing candidate biomarkers for neuropathologies that involve alterations in tissue microstructure. KANDO is illustrated for simple tissue models of white and gray matter using data obtained from healthy human subjects.postprin

Pain education for patients with non-specific low back pain in Nepal: Protocol of a feasibility randomised clinical trial (PEN-LBP Trial)

Introduction Low back pain (LBP) is the leading cause of years lived with disability in Nepal and elsewhere. Management of LBP that is evidence-based, easily accessible, cost-effective and culturally appropriate is desirable. The primary aim of this feasibility study is to determine if it is feasible to conduct a full randomised clinical trial evaluating the effectiveness of pain education as an intervention for individuals with LBP in Nepal, relative to guideline-based physiotherapy treatment. The findings of the study will inform the planning of a full clinical trial and if any modifications are required to the protocol before undertaking a full trial. Methods/analysis This protocol describes an assessor-blinded feasibility clinical trial investigating feasibility of the pain education intervention in patients with non-specific LBP in a physiotherapy hospital in Kathmandu, Nepal. Forty patients with LBP will be randomly allocated to either pain education or guideline-based physiotherapy treatment (control). Outcomes will be assessed at baseline and at a 1 week post-treatment. The primary outcomes are related to feasibility, including: (1) participant willingness to participate in a randomised clinical trial, (2) feasibility of assessor blinding, (3) eligibility and recruitment rates, (4) acceptability of screening procedures and random allocation, (5) possible contamination between the groups, (6) intervention credibility, (7) intervention adherence, (8) treatment satisfaction and (9) difficulty in understanding the interventions being provided. Ethics/dissemination The protocol was approved by Nepal Health Research Council (NHRC; registration number: 422/2017) and University of Otago Human Ethics Committee for Health (registration number: H17/157). The results of the study will be presented at national and international conferences and published in a peer-reviewed journal. Trial registration number NCT03387228; Pre-results

Results of a feasibility randomised clinical trial on pain education for low back pain in Nepal: The Pain Education in Nepal-Low Back Pain (PEN-LBP) feasibility trial

Objectives The aims of this study were to: (1) develop pain education materials in Nepali and (2) determine the feasibility of conducting a randomised clinical trial (RCT) of a pain education intervention using these materials in Nepal. Design A two-arm, parallel, assessor-blinded, feasibility RCT. Setting A rehabilitation hospital in Kathmandu, Nepal. Participants Forty Nepalese with non-specific low back pain (mean [SD] age 41 [14] years; 12 [30%] women). Interventions Eligible participants were randomised, by concealed, 1:1 allocation, to one of two groups: (1) a pain education intervention and (2) a guideline-based physiotherapy active control group intervention. Each intervention was delivered by a physiotherapist in a single, 1-hour, individualised treatment session. Primary outcome measures The primary outcomes were related to feasibility: recruitment, retention and treatment adherence of participants, feasibility and blinding of outcome assessments, fidelity of treatment delivery, credibility of, and satisfaction with, treatment. Assessments were performed at baseline and at 1 week post-treatment. Secondary outcome measures Pain intensity, pain interference, pain catastrophising, sleep disturbance, resilience, global rating of change, depression and quality of life. Statistical analyses were conducted blind to group allocation. Results Forty participants were recruited. Thirty-eight participants (95%) completed the 1-week post-treatment assessment. Most primary outcomes surpassed the a priori thresholds for feasibility. Several findings have important implications for designing a full trial. Secondary analyses suggest clinical benefit of pain education over the control intervention, with larger decrease in pain intensity (mean difference=3.56 [95% CI 0.21 to 6.91]) and pain catastrophising (mean difference=6.16 [95% CI 0.59 to 11.72]) in the pain education group. Pain intensity would seem an appropriate outcome for a full clinical trial. One minor adverse event was reported. Conclusion We conclude that a full RCT of pain education for back pain in Nepal is feasible and warranted. Trial registration number NCT03387228; Results

Breath-hold FSE for accurate imaging of myocardial and hepatic R2

Session 21: Hepatic Storage Disease - Oral presentationMRI provides a means to non-invasively assess tissue iron concentration by exploiting the paramagnetic effects of iron on T2 or T2*. The most widely used method is T2* imaging is sensitive to non-iron related magnetic field (B0) inhomogeneities, which can confound T2* measurements within the whole heart and liver. An alternative method is T2 imaging, but they are generally performed during free breathing with respiratory gating due to their low data acquisition efficiency. The purpose of this study was to develop a breath-hold fast spin echo (FSE) sequence for fast and accurate imaging of myocardial and hepatic T2.published_or_final_versionThe 17th Scientific Meeting & Exhibition of the International Society of Magnetic Resonance in Medicine (ISMRM), Honolulu, HI., 18-24 April 2009. In Proceedings of ISMRM 17th Scientific Meeting & Exhibition, 2009, p. 20

R2 imaging of ferritin iron in thalassaemia patients off and on iron-chelation therapy

Myocardial Tissue Characterization: Fat, Hemorrhage & Edema - Poster presentationAccurate assessment of iron burden is crucial for the management of iron-chelation therapy. MRI provides a means to non-invasively assess tissue iron concentration by exploiting the paramagnetic effects of iron on the relaxation rates of solvent protons. The most widely used method is R2* imaging, which has been shown to be sensitive to myocardial iron overload. Recently, a breath-hold fast spin echo sequence has been proposed for fast and accurate imaging of myocardial and hepatic R2. The purpose of this study was to determine which relaxation rates are sensitive to iron-chelation therapy.published_or_final_versionThe 17th Scientific Meeting & Exhibition of the International Society of Magnetic Resonance in Medicine (ISMRM), Honolulu, HI., 18-24 April 2009. In Proceedings of ISMRM 17th Scientific Meeting & Exhibition, 2009, p. 375

Diffusional Kurtosis and Diffusion Tensor Imaging Reveal Different Time-Sensitive Stroke-Induced Microstructural Changes

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Epilepsy-related cytoarchitectonic abnormalities along white matter pathways

Objective Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy. Unfortunately, the clinical outcomes of TLE cannot be determined based only on current diagnostic modalities. A better understanding of white matter (WM) connectivity changes in TLE may aid the identification of network abnormalities associated with TLE and the phenotypic characterisation of the disease. Methods We implemented a novel approach for characterising microstructural changes along WM pathways using diffusional kurtosis imaging (DKI). Along-the-tract measures were compared for 32 subjects with left TLE and 36 age-matched and gender-matched controls along the left and right fimbria-fornix (FF), parahippocampal WM bundle (PWMB), arcuate fasciculus (AF), inferior longitudinal fasciculus (ILF), uncinate fasciculus (UF) and cingulum bundle (CB). Limbic pathways were investigated in relation to seizure burden and control with antiepileptic drugs. Results By evaluating measures along each tract, it was possible to identify abnormalities localised to specific tract subregions. Compared with healthy controls, subjects with TLE demonstrated pathological changes in circumscribed regions of the FF, PWMB, UF, AF and ILF. Several of these abnormalities were detected only by kurtosis-based and not by diffusivity-based measures. Structural WM changes correlated with seizure burden in the bilateral PWMB and cingulum. Conclusions DKI improves the characterisation of network abnormalities associated with TLE by revealing connectivity abnormalities that are not disclosed by other modalities. Since TLE is a neuronal network disorder, DKI may be well suited to fully assess structural network abnormalities related to epilepsy and thus serve as a tool for phenotypic characterisation of epilepsy

Group Differences Between Countries and Between Languages in Pain-Related Beliefs, Coping, and Catastrophizing in Chronic Pain: A Systematic Review

Objective: To evaluate the extent to which pain-related beliefs, appraisals, coping, and catastrophizing differ between countries, language groups, and country economy. / Design: Systematic review. / Methods: Two independent reviewers searched 15 databases without restriction for date or language of publication. Studies comparing pain beliefs/appraisals, coping, or catastrophizing across two or more countries or language groups in adults with chronic pain (pain for longer than three months) were included. Two independent reviewers extracted data and performed the quality appraisal. Study quality was rated as low, moderate, or high using a 10-item modified STROBE checklist. Effect sizes were reported as small (0.20–0.49), medium (0.50–0.79), or large (≥0.80). / Results: We retrieved 1,365 articles, read 42 potential full texts, and included 10 (four moderate-quality, six low-quality) studies. A total of 6,797 adults with chronic pain (33% with chronic low back pain) were included from 16 countries. Meta-analysis was not performed because of heterogeneity in the studies. A total of 103 effect sizes were computed for individual studies, some of which indicated between-country differences in pain beliefs, coping, and catastrophizing. Of these, the majority of effect sizes for pain beliefs/appraisal (60%; eight large, eight medium, and eight small), for coping (60%; seven large, 11 medium, and 16 small), and for catastrophizing (50%; two medium, one small) evidenced statistically significant between-country differences, although study quality was low to moderate. / Conclusions: In 50% or more of the studies, mean scores in the measures of pain beliefs and appraisals, coping responses, and catastrophizing were significantly different between people from different countries

Cloud Occurrence Frequency at the Barrow, Alaska, ARM Climate Research Facility for 2008 Third Quarter 2009 ARM and Climate Change Prediction Program Metric Report

Clouds represent a critical component of the Earth’s atmospheric energy balance as a result of their interactions with solar and terrestrial radiation and a redistribution of heat through convective processes and latent heating. Despite their importance, clouds and the processes that control their development, evolution and lifecycle remain poorly understood. Consequently, the simulation of clouds and their associated feedbacks is a primary source of inter-model differences in equilibrium climate sensitivity. An important step in improving the representation of cloud process simulations is an improved high-resolution observational data set of the cloud systems including their time evolution. The first order quantity needed to understand the important role of clouds is the height of cloud occurrence and how it changes as a function of time. To this end, the Atmospheric Radiation Measurement (ARM) Climate Research Facilities (ACRF) suite of instrumentation has been developed to make the observations required to improve the representation of cloud systems in atmospheric models

Functional deficits induced by cortical microinfarcts

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