Sensitivity and Specificity of Whole-body MRI for the Detection of Pediatric Malignancy.

Children with cancer often present with general and nonspecific symptoms leading to initial diagnostic workup inclusive of clinical imaging. Various sequences of magnetic resonance imaging (MRI) are becoming more available for diagnostic imaging. However, there is currently a dearth of literature quantifying the sensitivity and specificity of whole-body MRI in identifying pediatric malignancy. In this study, a retrospective analysis was performed of pediatric whole-body MRI inclusive of short tau inversion recovery sequence conducted at an academic pediatric medical center from 2013 to 2018. Kappa statistics were used to evaluate the diagnostic agreement between MRI results and the gold standard diagnostic study of the respective final diagnosis. Sensitivity, specificity, false-positive, and false-negative estimates were provided with joint 90% confidence regions. One hundred forty-two patients received a whole-body MRI during the study period. The sensitivity of whole-body MRI in detecting malignancy was found to be 93.8% with a specificity of 93.4%. The positive and negative predictive values were determined to be 65.2% and 99.1%, respectively. Our findings suggest that whole-body MRI may be of value as an initial diagnostic tool for pediatric malignancy. Larger multicenter collaboration will be needed to further support these data.

Integrating safety, health and environmental management systems: A conceptual framework for achieving lean enterprise outcomes.

INTRODUCTION: Expectations from external stakeholders for eco-safe products and production processes and internal stakeholders for transparent, stable, and robust environment, safety, and health operations have driven high technology organizations to adopt multipart management systems. Organizations can protect workers and the environment and simultaneously contribute to lean management principles by implementing integrated management systems. This research adds to the existing discourse and theory pertaining to the integration of environment, safety, and health management systems. METHODS: The research was exploratory and inductive in nature and used mixed methods. Specifically, qualitative methods included use of an iterated Delphi method to elicit information from a panel of experts and detailed case studies conducted at four high technology performance manufacturing firms, while quantitative analysis of variance of correlated data investigated the within-firm and between-firm variability in motivating factors for adopting integrated systems and methods used for implementing integrated systems. RESULTS: The results offer an integrated-lean management system framework and the strategies available and used by a sample of high technology performance organizations to simultaneously protect workers, the environment, and support lean enterprise outcomes. Practical applications: Organizations can protect workers, the environment, and simultaneously contribute to lean management principles by implementing integrated management systems requiring joint management that allow for the shared design, evaluation, and continuous improvement of environmental, safety, and health practices that are compatible with the lean enterprise movement in today's high-performance driven organizations.

Neuroimaging and endocrine disorders in paediatric optic nerve hypoplasia.

PURPOSE: Optic nerve hypoplasia (ONH) is one of the leading causes of blindness among children. The purpose of this retrospective study is to determine the risk factors and association between brain MRI findings, pituitary abnormalities and endocrine disorders with the presence of ONH. METHODS: A retrospective review of patients seen at paediatric ophthalmology clinics from January 2006 to December 2016 at Children's Hospital and Medical Center and the University of Nebraska Medical Center was performed. All patients with a documented diagnosis of ONH or septo-optic dysplasia were identified. MRI and endocrinology results were analysed by masked examiners. RESULTS: Out of 77 patients, overall incidence of abnormal pituitary on MRI was 35.1% and the incidence of endocrine abnormalities was 37.7%. Of the 57 patients with bilateral ONH, 23 (40.4%) had an abnormal pituitary while 4 of the 20 patients (20.0%) with unilateral ONH had an abnormal pituitary on MRI. The sensitivity and specific of brain MRI as signs of endocrinopathy are 67.9% and 83.3%, respectively. CONCLUSION: This study has determined that abnormal MRI findings do not have the sensitivity to predict endocrinopathy, nor does a normal MRI rule out possible endocrine abnormalities. When patients with ONH present with normal neurological examinations, normal endocrine workup and normal developmental milestones, a MRI of the brain may be deferred until new indications arise. Regardless of the MRI status, children with ONH should have a comprehensive endocrine evaluation and continue to have routine endocrine follow-up.

Rapid and continuous magnetic separation in droplet microfluidic devices.

We present a droplet microfluidic method to extract molecules of interest from a droplet in a rapid and continuous fashion. We accomplish this by first marginalizing functionalized super-paramagnetic beads within the droplet using a magnetic field, and then splitting the droplet into one droplet containing the majority of magnetic beads and one droplet containing the minority fraction. We quantitatively analysed the factors which affect the efficiency of marginalization and droplet splitting to optimize the enrichment of magnetic beads. We first characterized the interplay between the droplet velocity and the strength of the magnetic field and its effect on marginalization. We found that marginalization is optimal at the midline of the magnet and that marginalization is a good predictor of bead enrichment through splitting at low to moderate droplet velocities. Finally, we focused our efforts on manipulating the splitting profile to improve the enrichment provided by asymmetric splitting. We designed asymmetric splitting forks that employ capillary effects to preferentially extract the bead-rich regions of the droplets. Our strategy represents a framework to optimize magnetic bead enrichment methods tailored to the requirements of specific droplet-based applications. We anticipate that our separation technology is well suited for applications in single-cell genomics and proteomics. In particular, our method could be used to separate mRNA bound to poly-dT functionalized magnetic microparticles from single cell lysates to prepare single-cell cDNA libraries.