Imaging of pediatric adrenal tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Adrenal tumors other than neuroblastoma are uncommon in children. The most frequently encountered are adrenocortical carcinoma and pheochromocytoma. This paper offers consensus recommendations for imaging of pediatric patients with a known or suspected primary adrenal malignancy other than neuroblastoma at diagnosis and during follow-up.     

Prognostic value of modified National Institute of Health activity and chronicity scoring in determining complete renal response in newly diagnosed lupus nephritis: a retrospective single centre study

International Urology and Nephrology - Early response to therapy is associated with favourable long-term outcome in LN. The working group of revision of ISN/RPS classification guidelines for LN...     

Controversies in cardio-nephrology: contrast nephropathy

International Urology and Nephrology -     

A comment on the severity of the effects of non-white noise in fMRI time-series

Analysis of fMRI time-series data is usually performed within the general linear model (GLM), and conclusions are based on the probability (p) of a false-positive voxel. In its simplest form, this process assumes that temporal noise in the time-series is random (white); if it is not, then an error in the estimation of p will occur. Various methods for correcting the problem have been developed, but they are not always used. Analysis packages vary in their ability to deal with this problem, and there is a lack of consistent advice to non-experts concerning whether this issue is serious or is small enough to be ignored. The variability of expert opinion partly reflects the fact that the magnitude of the error that occurs when estimating p in fMRI data is largely undocumented. In this discussion, aimed more at "neuroscience users" than methods experts, we try to clarify the position by documenting the scale of the error in a simple block-design experiment. Based on a fixed-effects group analysis of null datasets (8 participants scanned while at rest), we show that the magnitude of the problem can be very substantial. Without correction, it was necessary to set a nominal probability threshold of about p=0.000001 in order to achieve an actual probability of a false positive of 0.001. This means that if task-related activations were present in such a dataset, only if they reached the former, very low nominal p value could they be relied upon. With the use of standard correction methods, the error was largely removed. Our results suggest that some form of pre-whitening or correction for effects of non-white noise is essential in single-subject GLM analyses and fixed-effects group analyses of fMRI data. It is less important but probably prudent to apply a correction at the first level of random-effects group analyses. We also evaluate the effect of high-pass filtering. We find that the number of false positives in a fixed-effects analysis increases markedly as the filter cut-off frequency is increased. The sensitivity benefits derived from high-pass filtering may thus be partially offset by a significant increase in the number of false positives.     

Intralenticular changes in eyes with mature senile cataract on modified posterior segment optical coherence tomography

Purpose:To study the morphological changes within mature senile cataracts on modified posterior segment optical coherence tomography (OCT).Methods:A cross-sectional observational study recruiting patients of mature cataracts admitted for elective cataract surgery in tertiary eye care. A modified OCT imaging of the lens was done and lenticular findings were noted by a single observer. Corresponding slit-lamp biomicroscopic findings and intraoperative experiences were also noted by a second observer and respective surgeons.Results:Forty-four eyes of 44 patients were included. The mean age of patients was 65 ± 5.7 years. The intralenticular findings were uniform in groups of eyes, and they were characterized into three stages. First was a stage of early lamellar separation where small intralenticular clefts were noted superficially. Second was the stage of established lamellar separation where crescentic fluid clefts appeared interspersed between the lens fibers, and the depth increased as a function of severity. Both these stages did not show any distinct slit-lamp or intraoperative findings. A third stage of liquefaction identified as extensive lamellar separation with subcapsular fluid pockets. This was also reflected in slit-lamp biomicroscopy, showing the hydrated cortex with intraoperative challenges. Two cases showed peculiar changes, one of a hyperreflective subcapsular sheath and another of superficial nuclear lamellar separation.Conclusion:Mature cataracts may also show graded progression, which could be delineated on lenticular OCT. This could be of immense help in pre-operative planning and optimal management of these high-risk cases.     

CAD/CAE of Jaipur foot for standardized and contemporary manufacturing

Abstract

Objective: Despite immense popularity of Jaipur foot as low cost prosthetic, not much work has been reported on its design for manufacturing standardization. Without manufacturing standardization, it cannot be mass produced using contemporary manufacturing technologies. The objective of this work is to carry out its computer aided design (CAD) followed by computer aided engineering (CAE) based on the material properties obtained from the previous work [1 Rachel HT, Kristine MF, Benjamin BW, et al. Assessment of the compressive and tensile mechanical properties of materials used in the Jaipur foot prosthesis. Prosthet Orthot Int. 2018;42:511–517.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]] of the authors. This may lead to the possible use of modern manufacturing processes for the Jaipur foot design.

Design: After modelling using CAD tool including its organic surfaces, the designed foot was analysed using a CAE tool for balanced standing load conditions to determine maximum stresses and deformation in its various parts. The bending analysis was done to check the dorsiflexion movement so that the strained sections could be identified for more reliable and durable prosthetic foot. For the static load analysis, base of the foot was constrained and 300–500 N load was applied through the bolt whereas for bending, the part near the bolt was fixed and pressure was applied at junction of front foot and toes.

Results: The results show that the maximum stress and deformation occur at the bolt, while the skin undergoes maximum strain. CAE analysis also proves the robustness of the Jaipur foot design and a well manufactured Jaipur foot as per standardized design should be able to withstand the real life conditions without failure. The CAD model is also used for FDM based printing for a nonfunctional prototype of Jaipur foot.

• Implications for rehabilitation

• The results of this study will serve as an important guideline for further research regarding equivalent material replacement, material optimization and obtaining an optimized design after studying the foot for dynamic analysis.