The role of diffusion tensor imaging in characterizing injury patterns on athletes with concussion and subconcussive injury: a systematic review.

Traumatic brain injury (TBI) is a major public health problem. The majority of TBIs are in the form of mild TBI (also known as concussion) with sports-related concussion (SRC) receiving public attention in recent years.Here we have performed a systematic review of the literature on the use of Diffusion Tensor Imaging (DTI) on sports-related concussion and subconcussive injuries. Our review found different patterns of change in DTI parameters between concussed and subconcussed groups. The Fractional Anisotropy (FA) was either unchanged or increased for the concussion group, while the subconcussed group generally experienced a decrease in FA. A reverse pattern was observed for Mean Diffusivity (MD) - where the concussed group experienced a decrease in MD while the subconcussed group showed an increase in MD. However, in general, discrepancies were observed in the results reported in the literature - likely due to the huge variations in DTI acquisition parameters, and image processing and analysis methods used in these studies. This calls for more comprehensive and well-controlled studies in this field, including those that combine the advanced brain imaging with biomechancial modeling and kinematic sensors - to shed light on the underlying mechanisms behind the structural changes observed from the imaging studies.

Integration of diffusion tensor imaging parameters with mesh morphing for in-depth analysis of brain white matter fibre tracts.

Averaging is commonly used for data reduction/aggregation to analyse high-dimensional MRI data, but this often leads to information loss. To address this issue, we developed a novel technique that integrates diffusion tensor metrics along the whole volume of the fibre bundle using a 3D mesh-morphing technique coupled with principal component analysis for delineating case and control groups. Brain diffusion tensor MRI scans of high school rugby union players (n = 30, age 16-18) were acquired on a 3 T MRI before and after the sports season. A non-contact sport athlete cohort with matching demographics (n = 12) was also scanned. The utility of the new method in detecting differences in diffusion tensor metrics of the right corticospinal tract between contact and non-contact sport athletes was explored. The first step was to run automated tractography on each subject's native space. A template model of the right corticospinal tract was generated and morphed into each subject's native shape and space, matching individual geometry and diffusion metric distributions with minimal information loss. The common dimension of the 20 480 diffusion metrics allowed further data aggregation using principal component analysis to cluster the case and control groups as well as visualization of diffusion metric statistics (mean, ±2 SD). Our approach of analysing the whole volume of white matter tracts led to a clear delineation between the rugby and control cohort, which was not possible with the traditional averaging method. Moreover, our approach accounts for the individual subject's variations in diffusion tensor metrics to visualize group differences in quantitative MR data. This approach may benefit future prediction models based on other quantitative MRI methods.

The Effectiveness of Perovskia abrotanoides Extract Topical Formulation on the Cutaneous Leishmaniasis: A Randomized Controlled Clinical Trial.

Objective: Despite many attempts to treat leishmaniasis, new approaches are necessary to reduce the burden of disease. Perovskia abrotanoides (Brazambel) has shown significant effects against Leishmania parasites in some studies. This study aimed to investigate the effects of P. abrotanoides extract topical formulation on cutaneous leishmaniasis. Methods: In this randomized controlled clinical trial, patients with cutaneous leishmaniasis were assigned to experimental (n = 18) and control (n = 18) groups. Both groups received intralesional meglumine antimoniate (Glucantime®). The experimental group also received 5% Brazambel extract ointment once a day. The interventions continued until the complete healing of the lesions (reepithelialization) for a maximum of 8 weeks. The clinical response, defined as complete response (reepithelialization >75%), partial response (reepithelialization 50%-75%), or treatment failure (reepithelialization <50%), was compared between the groups. Findings: The percentage of reepithelialization in the experimental group (4th week: 64.44 ± 25.13; 8th week: 83.85 ± 11.54) was higher than the control group (4th week: 53.97 ± 25.88; 8th week: 76.27 ± 21.67); however, the differences were not statistically significant (P = 0.252 and 0.494, respectively). Moreover, there was no significant difference between the experimental and control groups regarding the rate of complete healing (88.9% vs. 72.2%, respectively). Conclusion: The use of P. abrotanoides extract 5% topical formulation does not affect the healing of cutaneous leishmaniasis.

Atlas-Free Automatic Segmentation of Sheep Brain MRI.

Automated 3D brain segmentation methods have been shown to produce fast, reliable, and reproducible segmentations from magnetic resonance imaging (MRI) sequences for the anatomical structures of the human brain. Despite the extensive experimental research utility of large animal species such as the sheep, there is limited literature on the segmentation of their brains relative to that of humans. The availability of automatic segmentation algorithms for animal brain models can have significant impact for experimental explorations, such as treatment planning and studying brain injuries. The neuroanatomical similarities in size and structure between sheep and humans, plus their long lifespan and docility, make them an ideal animal model for investigating automatic segmentation methods.This work, for the first time, proposes an atlas-free fully automatic sheep brain segmentation tool that only requires structural MR images (T1-MPRAGE images) to segment the entire sheep brain in less than one minute. We trained a convolutional neural network (CNN) model - namely a four-layer U-Net - on data from eleven adult sheep brains (training and validation: 8 sheep, testing: 3 sheep), with a high overall Dice overlap score of 93.7%.Clinical relevance- Upon future validation on larger datasets, our atlas-free automatic segmentation tool can have clinical utility and contribute towards developing robust and fully automatic segmentation tools which could compete with atlas-based tools currently available.

Roadmap for an imaging and modelling paediatric study in rural NZ.

Our study methodology is motivated from three disparate needs: one, imaging studies have existed in silo and study organs but not across organ systems; two, there are gaps in our understanding of paediatric structure and function; three, lack of representative data in New Zealand. Our research aims to address these issues in part, through the combination of magnetic resonance imaging, advanced image processing algorithms and computational modelling. Our study demonstrated the need to take an organ-system approach and scan multiple organs on the same child. We have pilot tested an imaging protocol to be minimally disruptive to the children and demonstrated state-of-the-art image processing and personalized computational models using the imaging data. Our imaging protocol spans brain, lungs, heart, muscle, bones, abdominal and vascular systems. Our initial set of results demonstrated child-specific measurements on one dataset. This work is novel and interesting as we have run multiple computational physiology workflows to generate personalized computational models. Our proposed work is the first step towards achieving the integration of imaging and modelling improving our understanding of the human body in paediatric health and disease.

A window into eye movement dysfunction following mTBI: A scoping review of magnetic resonance imaging and eye tracking findings.

Mild traumatic brain injury (mTBI), commonly known as concussion, is a complex neurobehavioral phenomenon affecting six in 1000 people globally each year. Symptoms last between days and years as microstructural damage to axons and neurometabolic changes result in brain network disruption. There is no clinically available objective biomarker to diagnose the severity of injury or monitor recovery. However, emerging evidence suggests eye movement dysfunction (e.g., saccades and smooth pursuits) in patients with mTBI. Patients with a higher symptom burden and prolonged recovery time following injury may show higher degrees of eye movement dysfunction. Likewise, recent advances in magnetic resonance imaging (MRI) have revealed both white matter tract damage and functional network alterations in mTBI patients, which involve areas responsible for the ocular motor control. This scoping review is presented in three sections: Section 1 explores the anatomical control of eye movements to aid the reader with interpreting the discussion in subsequent sections. Section 2 examines the relationship between abnormal MRI findings and eye tracking after mTBI based on the available evidence. Finally, Section 3 communicates gaps in our knowledge about MRI and eye tracking, which should be addressed in order to substantiate this emerging field.

Investigating the relationship between carotid intima-media thickness, flow-mediated dilatation in brachial artery and nuclear heart scan in patients with rheumatoid arthritis for evaluation of asymptomatic cardiac ischemia and atherosclerotic changes.

BACKGROUND: Cardiovascular disease is the most common cause of death worldwide. In order to prevent and treat heart diseases, we need to estimate the trend of non-cardiac diseases with the cardiovascular system. Arthritis Rheumatoid is a chronic immune/inflammatory process which leads to subclinical atherosclerosis and increases cardiovascular disease. We examined the patients who referred to our nuclear medicine center for MPI and correlated their findings with flow-mediated dilatation (FMD) of the brachial artery and carotid intima-media thickness (CIMT) in arthritis rheumatoid patients. MATERIAL AND METHODS: A total 30 known cases with arthritis rheumatoid were referred to our department for MPI and the single-photon emission computed tomography (SPECT) imaging were visually and quantitatively evaluated by two nuclear medicine physicians and the correlation of the measured FMD and CIMT were evaluated and compared with ultrasonography data. Demographic information such as gender, age and sex and medical history (risk factors, cardiovascular sign and symptoms, lab findings, medication etc…) were recorded in questionnaire sheets and were analyzed by SPSS.20. Chi-square and student t-test were used for further analysis. RESULTS: The mean CIMT (R = 0.452 ± 0.07, L = 0.447 ± 0.08) and %FMD (R = 7.22 ± 8.66, L = 6.42 ± 11.88) were measured for all subjects. Age was the only parameter correlated with both right and left CIMT (P = 0.033 and P = 0.024, respectively). Among the patients, 26.7% had mild ischemia (SSS < 8) and 3 of them suffered from active arthritis rheumatoid. All patients with RA showed normal ventricular ejection fraction and normal volumes and among them, 93.3% had normal functional performance (normal wall motion…). Moreover, the mean CIMT and %FMD were not significantly different in ischemic and non-ischemic patients. Among ischemic patients, just the course of the disease was associated with CIMT and none of the parameters was correlated with FMD. CONCLUSIONS: There is no significant statistical difference between ischemic and non-ischemic patients and also the functional performance with values of CIMT and FMD. Among all populations, the parameter of age, and in ischemic group, the course of disease were found as the only variable correlated with CIMT.

Evaluation of subacute subarachnoid haemorrhage detection using a magnetic resonance imaging sequence: Double inversion recovery.

BACKGROUND AND OBJECTIVES: The diagnosis of subarachnoid hemorrhage (SAH) especially at the subacute stage is still a challenging issue using the conventional imaging modalities. Here we evaluated the role of double inversion recovery (DIR) sequence of MRI compared with the conventional gradient-recalled echo (GRE)-T2*-W and susceptibility-weighted imaging (SWI) sequences in the diagnosis of subacute SAH. MATERIALS AND METHODS: This prospective study was conducted on 21 patients with SAH, which were diagnosed using CT scan at the initial step. In the third week after the injury (14-20 days), all patients underwent a brain MRI exam that included T2*-W, SWI, and DIR imaging sequences. All images were independently read by two radiologists, who were blinded to the clinical history of the patients. The presence or absence of SAH was reviewed and assessed in 6 anatomical regions. RESULTS: On the DIR images, 20 patients were found to have at least one subarachnoid signal abnormality, while the SWI and T2*-W images identified SAH areas on 17 and 15 patients, respectively. The highest rate of inter-observer consensus by the DIR sequence was found in the interhemispheric fissure and perimesencephalic area (k = 1). Also, a highest rate of inter-observer consensus using SWI was found in the interhemispheric fissure and posterior fossa cistern area (k = 1). A weak agreement was found in frontal-parietal convexity using SWI (k = 0.447), and in posterior fossa cistern by the T2* sequence (k = 0.447). CONCLUSION: In conclusion, the DIR sequence was more reliable at identifying signal abnormalities in subacute SAH patients than the T2*-W and SWI sequence, and is suggested as a promising imaging technique for detecting hemorrhagic areas without considering the anatomical distribution of SAH.

Novel strain analysis informs about injury susceptibility of the corpus callosum to repeated impacts.

Increasing evidence for the cumulative effects of head trauma on structural integrity of the brain has emphasized the need to understand the relationship between tissue mechanic properties and injury susceptibility. Here, diffusion tensor imaging, helmet accelerometers and amplified magnetic resonance imaging were combined to gather insight about the region-specific vulnerability of the corpus callosum to microstructural changes in white-matter integrity upon exposure to sub-concussive impacts. A total of 33 male Canadian football players (meanage = 20.3 ± 1.4 years) were assessed at three time points during a football season (baseline pre-season, mid-season and post-season). The athletes were split into a LOW (N = 16) and HIGH (N = 17) exposure group based on the frequency of sub-concussive impacts sustained on a per-session basis, measured using the helmet-mounted accelerometers. Longitudinal decreases in fractional anisotropy were observed in anterior and posterior regions of the corpus callosum (average cluster size = 40.0 ± 4.4 voxels; P < 0.05, corrected) for athletes from the HIGH exposure group. These results suggest that the white-matter tract may be vulnerable to repetitive sub-concussive collisions sustained over the course of a football season. Using these findings as a basis for further investigation, a novel exploratory analysis of strain derived from sub-voxel motion of brain tissues in response to cardiac impulses was developed using amplified magnetic resonance imaging. This approach revealed specific differences in strain (and thus possibly stiffness) along the white-matter tract (P < 0.0001) suggesting a possible signature relationship between changes in white-matter integrity and tissue mechanical properties. In light of these findings, additional information about the viscoelastic behaviour of white-matter tissues may be imperative in elucidating the mechanisms responsible for region-specific differences in injury susceptibility observed, for instance, through changes in microstructural integrity following exposure to sub-concussive head impacts.

Large hiatal hernia with pancreatic body herniation: Case-report.

INTRODUCTION: A hiatal hernia can be classified as one of four types according to the position of the gastroesophageal (GE) junction and the extent of herniated stomach. Type IV paraesophageal hiatal hernia (PEHH) is characterized by a large defect in the diaphragmatic hiatus that allows other organs, besides stomach, such as the colon, pancreas, spleen, or small intestine to herniate into the thorax. Herniation of the pancreas through a gastroesophageal hiatus is a rare condition, and only a few cases have been reported in the literature. CASE REPORT: We present a case of an asymptomatic patient with paraesophageal herniation along with the body and tail of the pancreas. CONCLUSION: However, surgery is optimal choice for symptomatic patients, it is important for surgeons to consider the risks of different approaches and choose the best intervention.

Case Report: Synchronous primary malignancy including the breast and endometrium.

Breast and endometrial cancer are the most common types of female cancers, but the incidence of both of these malignancies in a single patient is a rare event. Multiple primary malignancy has been increasingly reported over the past decade, and double primary cancer is considered as the most common type.  In this study, we present a 53-year-old woman with synchronous primary malignancy of breast and endometrium. This patient had a history of breast and endometrial cancer in her family. Mammography and chest CT of the patient revealed a mass in the right breast and left supraclavicular region. However, the patient did not want to initiate treatment. Subsequently, the patient returned with a chief complaint of persistent abnormal vaginal bleeding. Abdominopelvic CT scan of the patient revealed a huge soft tissue mass in the pelvic cavity. She underwent hysterectomy, and pathology revealed endometrioid carcinoma, which had invaded the full thickness of uterine wall. Since this type of malignancy is rare and several risk factors are associated with it, it is worth being considered by clinicians when making decisions about screening or strategy for prevention.