Theoretical model for laser ablation outcome predictions in brain: calibration and validation on clinical MR thermometry images

Purpose: Neurosurgical laser ablation is experiencing a renaissance. Computational tools for ablation planning aim to further improve the intervention. Here, global optimisation and inverse problems are demonstrated to train a model that predicts maximum laser ablation extent.

Methods: A closed-form steady state model is trained on and then subsequently compared to N?=?20 retrospective clinical MR thermometry datasets. Dice similarity coefficient (DSC) is calculated to provide a measure of region overlap between the 57?°C isotherms of the thermometry data and the model-predicted ablation regions; 57?°C is a tissue death surrogate at thermal steady state. A global optimisation scheme samples the dominant model parameter sensitivities, blood perfusion (ω) and optical parameter (μ_eff) values, throughout a parameter space totalling 11?440 value-pairs. This represents a lookup table of μ_eff–ω pairs with the corresponding DSC value for each patient dataset. The μ_eff–ω pair with the maximum DSC calibrates the model parameters, maximising predictive value for each patient. Finally, leave-one-out cross-validation with global optimisation information trains the model on the entire clinical dataset, and compares against the model naïvely using literature values for ω and μ_eff.

Results: When using naïve literature values, the model’s mean DSC is 0.67 whereas the calibrated model produces 0.82 during cross-validation, an improvement of 0.15 in overlap with the patient data. The 95% confidence interval of the mean difference is 0.083–0.23 (p?Conclusions: During cross-validation, the calibrated model is superior to the naïve model as measured by DSC, with +22% mean prediction accuracy. Calibration empowers a relatively simple model to become more predictive.     

Glucosamine alleviates scopolamine induced spatial learning and memory deficits in rats

Introduction and objectiveBeneficial effects of glucosamine in spatial learning and memory impairment induced by scopolamine has been evaluated in rats by using Morris water maze.MethodsMale Wistar rats were randomly divided into control, scopolamine and scopolamine plus glucosamine groups. All injections were given in 5 consecutive days and 30 min after each injection, the rats were tested in the Morris water maze test. Escape latency and path length to reach the hidden platform were subjected to analysis of variance [ANOVA].ResultsThe rats treated with scopolamine showed increased escape latency and path length to reach the hidden platform compared to control group (P < 0.001). Both escape latency and traveled path length to reach the hidden platform in glucosamine treated animals (1 and 2 g/kg) were significantly lower (P < 0.05 to P < 0.001) than in the scopolamine group.ConclusionThe results of this study showed that the glucosamine can inhibit scopolamine-induced impairments of spatial learning and memory in rats. Glucosamine might offer a promise in either the prevention or the treatment of neurodegenerative diseases such as Alzheimer's disease.     

EFAS Score —Validation of Persian Version by the Score Committee of the European Foot and Ankle Society (EFAS)

BackgroundThe Score Committee of the European Foot and Ankle Society (EFAS) developed, validated, and published the EFAS Score in nine European languages (English, German, French, Italian, Polish, Dutch, Swedish, Finnish, Turkish). From other languages under validation, the Persian version finished data acquisition and underwent further validation.MethodsThe Persian version of the EFAS Score was developed and validated in three stages: 1) item (question) identification (completed during initial validation study), 2) item reduction and scale exploration (completed during initial validation study), 3) confirmatory analyses and responsiveness of Persian version (completed during initial validation study in nine other languages). The data were collected pre-operatively and post-operatively at a minimum follow-up of 3 months and mean follow-up of 6 months. Item reduction, scale exploration, confirmatory analyses and responsiveness were executed using classical test theory and item response theory.ResultsThe internal consistency was confirmed in the Persian version (Cronbach’s Alpha 0.82). The Standard Error of Measurement (SEM) was 0.38 and is similar to other language versions. Between baseline and follow-up, 97% of patients showed an improvement on their EFAS score, with excellent responsiveness (effect size 1.93).ConclusionsThe Persian EFAS Score version was successfully validated in patients with a wide variety of foot and ankle pathologies. All score versions are freely available at www.efas.co.     

Cognitive determinants of cervical cancer screening behavior among housewife women in Iran: An application of Health Belief Model

Our aim in this cross-sectional study was to assess the cognitive determinants of Cervical Cancer Screening Behavior (CCSB) among housewife women in Islamabad County, Iran. Through multistage random sampling we recruited and interviewed 280 housewife women. The women who perceived more benefits of performing the Pap test (OR = 1.11), and perceived fewer barriers (OR = 0.915), and higher self-efficacy to perform the test (OR = 1.12) were more likely to have a CCSB in the previous three years. Our findings are informative for the development of targeted interventions to foster CCSB among housewife women.