Radiomics-Based Assessment of OCT Angiography Images for Diabetic Retinopathy Diagnosis.

Purpose: To evaluate the diagnostic accuracy of machine learning (ML) techniques applied to radiomic features extracted from OCT and OCT angiography (OCTA) images for diabetes mellitus (DM), diabetic retinopathy (DR), and referable DR (R-DR) diagnosis. Design: Cross-sectional analysis of a retinal image dataset from a previous prospective OCTA study (ClinicalTrials.govNCT03422965). Participants: Patients with type 1 DM and controls included in the progenitor study. Methods: Radiomic features were extracted from fundus retinographies, OCT, and OCTA images in each study eye. Logistic regression, linear discriminant analysis, support vector classifier (SVC)-linear, SVC-radial basis function, and random forest models were created to evaluate their diagnostic accuracy for DM, DR, and R-DR diagnosis in all image types. Main Outcome Measures: Area under the receiver operating characteristic curve (AUC) mean and standard deviation for each ML model and each individual and combined image types. Results: A dataset of 726 eyes (439 individuals) were included. For DM diagnosis, the greatest AUC was observed for OCT (0.82, 0.03). For DR detection, the greatest AUC was observed for OCTA (0.77, 0.03), especially in the 3 × 3 mm superficial capillary plexus OCTA scan (0.76, 0.04). For R-DR diagnosis, the greatest AUC was observed for OCTA (0.87, 0.12) and the deep capillary plexus OCTA scan (0.86, 0.08). The addition of clinical variables (age, sex, etc.) improved most models AUC for DM, DR and R-DR diagnosis. The performance of the models was similar in unilateral and bilateral eyes image datasets. Conclusions: Radiomics extracted from OCT and OCTA images allow identification of patients with DM, DR, and R-DR using standard ML classifiers. OCT was the best test for DM diagnosis, OCTA for DR and R-DR diagnosis and the addition of clinical variables improved most models. This pioneer study demonstrates that radiomics-based ML techniques applied to OCT and OCTA images may be an option for DR screening in patients with type 1 DM. Financial Disclosures: Proprietary or commercial disclosure may be found after the references.

Nanodrops of Discotic Liquid Crystals: A Monte Carlo Study.

We study the morphologies of nematic nanodrops in a vapor of a discotic nematogen by Monte Carlo simulations. The fluid interactions are modeled by a Gay-Berne model with molecular elongations of κ = 0.3 and 0.5 and different values of the energy anisotropy parameter κ' in the range of temperature T in which the nematic coexists with a vapor phase. We considered nanodrops of N = 4000 and 32 000 particles. For κ > κ', we observe that nanodrops are quite spherical (even for N = 4000 nanodrops), with a homogeneous director field for κ = 0.3 and a bipolar nematic configuration with tangential anchoring for κ = 0.5. By increasing the value of κ', nanodrops change from spherical to lens-shaped for κ = 0.3, and for κ = 0.5, spherical nanodrops with homeotropic anchoring and a disclination ring located on its equatorial plane are observed. Although no radial nanodrops are observed, isotropic liquid nanodrops with a paranematic shell and radial texture are observed for temperatures slightly above the vapor-isotropic-nematic triple point when the vapor-isotropic interface is completely wet by the nematic phase.

Flue gas adsorption by single-wall carbon nanotubes: A Monte Carlo study.

Adsorption of flue gases by single-wall carbon nanotubes (SWCNT) has been studied by means of Monte Carlo simulations. The flue gas is modeled as a ternary mixture of N2, CO2, and O2, emulating realistic compositions of the emissions from power plants. The adsorbed flue gas is in equilibrium with a bulk gas characterized by temperature T, pressure p, and mixture composition. We have considered different SWCNTs with different chiralities and diameters in a range between 7 and 20 Å. Our results show that the CO2 adsorption properties depend mainly on the bulk flue gas thermodynamic conditions and the SWCNT diameter. Narrow SWCNTs with diameter around 7 Å show high CO2 adsorption capacity and selectivity, but they decrease abruptly as the SWCNT diameter is increased. For wide SWCNT, CO2 adsorption capacity and selectivity, much smaller in value than for the narrow case, decrease mildly with the SWCNT diameter. In the intermediate range of SWCNT diameters, the CO2 adsorption properties may show a peculiar behavior, which depend strongly on the bulk flue gas conditions. Thus, for high bulk CO2 concentrations and low temperatures, the CO2 adsorption capacity remains high in a wide range of SWCNT diameters, although the corresponding selectivity is moderate. We correlate these findings with the microscopic structure of the adsorbed gas inside the SWCNTs.

Economic impact of and satisfaction with a high resolution thyroid nodule clinic at the endocrinology department. / Impacto económico y satisfacción de la implantación de una consulta de alta resolución de patología nodular tiroidea en Endocrinología.

BACKGROUND AND OBJECTIVE: No conclusive data exist on the value of a high resolution thyroid nodule clinic for management of nodular thyroid disease. The aim of this study was to evaluate the economic impact of and user satisfaction with a high resolution thyroid nodule clinic (HRTNC) in coordination with primary care. PATIENTS AND METHOD: A prospective, observational, descriptive study was conducted to analyze data from 3,726 patients (mean age 61±12 years; 85% women) evaluated at an HRTNC during 2014 and 2015. Demographic data (sex and age), number of ultrasound examinations and fine needle aspiration cytologies (FNAC), referral center and consultation type were assessed. RESULTS: In 2014 and 2015, 3,726 neck ultrasound examinations and 926 FNACs (3.8% rated as non-diagnostic) were performed. Among the 1,227 patients evaluated for the first time, 21.5% did not require a second endocrine appointment, which resulted in mean estimated savings of 14,354.55 euros. Of all patients, 41.1% were referred from primary care, 33.4% from endocrinology, and 26.5% from other specialties. As compared to 2013, the number of thyroid ultrasound examinations requested decreased by 65.3% and 59.7% in 2014 and 2015 respectively, with mean estimated savings of 137,563.92 euros. Mean user satisfaction assessed was 4.0 points (95% confidence interval, 3.7-4.3) on a 5-point scale. CONCLUSIONS: HRTNCs at endocrinology departments, coordinated with primary care, are a viable, cost-effective alternative with a positive user perception.

The predictive capacity of the Glasgow-Blatchford score for the risk stratification of upper gastrointestinal bleeding in an emergency department.

OBJECTIVES: To assess the ability of the Glasgow Blatchford Score (GBS) system to identify the need for urgent upper gastrointestinal endoscopy (UGIE) in patients with upper gastrointestinal bleeding (UGIB). METHODS: An observational, retrospective study was carried out in all patients attended at the ER for suspected UGIB in one year. Patients were split into two categories -high-risk (>2) and low-risk ( < or = 2)- by means of the GBS system. RESULTS: A total of 60 patients were included. Of these, 46 were classified as "high-risk" (> 2) and 14 as "low-risk" ( < or = 2) subjects.The characteristics of patients in the low-risk group included: Mean age: 46.6 +/- 13.7 (18-88) years. Males/females: 7/7. Urgent endoscopy revealed: normal (50%; n = 7); esophagitis (21.4%; n = 3); gastritis (14.2%; n = 2); Mallory-Weiss syndrome (7.1%; n = 1); non-bleeding varices (7.1%; n = 1). The characteristics of patients in the high-risk group included: Mean age: 68.7 +/- 19.8 (31-91) years. Males/females: 30/16. Digestive endoscopy revealed: Gastric/duodenal ulcer (56.52%; n = 26); normal (17.39%; n = 8); esophagitis (8.69%; n = 4); gastritis (8.69%; n = 4); angioectasia (4.34%; n = 2); bleeding varices (4.34%; n = 2). Low-risk patients exhibited no lesions requiring urgent management during endoscopy, and the sensitivity of the GBS scale for high-risk UGIB detection was found to be 100% (95% CI: 86.27%, 99.71%), with a specificity of 48.28% (95% CI: 29.89, 67.1%). CONCLUSIONS: The GBS scale seems to accurately identify patients with low-risk UGIB, who may be managed on an outpatient basis and undergo delayed upper GI endoscopy at the outpatient clinic.

The cost associated with interstitial thermotherapy for tonsil reduction vs. standard tonsillectomy.

Given the high demand for tonsillectomies in children, the variety of techniques available, and the increasing need to control expenditures, it is important to analyse the costs associated with surgical procedures. The aim in the present study was to compare the cost of interstitial thermotherapy for tonsil volume reduction with conventional tonsillectomy. This was a nonrandomized, retrospective analysis at a public practice regional hospital between 2010 and 2012. Paediatric patients that underwent molecular resonance (MR)-induced tonsil thermal ablation (day case admission) were matched, according to age and concurrent surgery, to patients that underwent tonsillectomy by standard bipolar dissection (ordinary admission) during the same study period. Both groups were compared in economic terms based on operating room (OR) times, salaries, materials and hospitalization cost. Sixty-two patients were included (31 in each group). The mean ages of patients in the MR and tonsillectomy groups were 5.6 (2.7 SD) and 5.1 years (2.0 SD), respectively. A significantly lower mean surgery time (28.25 vs. 36.95 min), anaesthesia time (48.79 vs. 61.73 min), OR time (64.18 vs. 76.16 min), and OR cost (€166.60 vs. €199.58) were found in the MR group (P < 0.05). The mean cost-per-patient was significantly higher in the MR technique when the expenses of the single-use probe and the overnight stay were, respectively, added (€408.60 vs. €374.58, P = 0.007). The present study confirmed increased costs for interstitial thermotherapy for tonsil reduction compared to conventional tonsillectomy. Operation time and early discharge savings were eclipsed by the cost of the disposable probes.

La valoración preoperatoria en el adulto / Preoperative evaluation in adults

Este trabajo pretende reconsiderar la utilidad y las indicaciones de la valoración preoperatoria en el adulto. Se estudió de manera prospectiva una cohorte de 791 pacientes candidatos a tratamiento quirúrgico, mayores de 40 años, que contaban con citología hemática, glucosa en sangre, urea, creatinina, sodio y potasio séricos, tiempo de protrombina, tiempo de tromboplastina parcial, cuenta de plaquetas, pruebas de funcionamiento hepático, telerradiografía de tórax en posteroanterior y electrocardiograma. Se buscaron complicaciones postoperatorias cardiovasculares, renales, hepáticas, pulmonares, hemorrágicas trans y postoperatorias, infecciosas y alteraciones metabólicas, mediante una visita diaria que se continuó hasta el egreso hospitalario. Se calculó el riesgo relativo (RR) de cada una de la variables, para predecir cada una de las complicaciones, valorando las diferencias con X² y prueba exacta de Fisher. Las variables estadísticamente significativas se sometieron a regresión logística. Se estudiaron 751 pacientes, 335 hombres (44 por ciento) y 416 mujeres (56 por ciento), con edad promedio de 63.9 años. Las complicaciones más frecuentes fueron las alteraciones metabólicas (16.9 por ciento) y las infecciones postoperatorias (7.0). La hemorragia trans o postoperatoria tuvo una frecuencia de 2.2 por ciento. Hubo 17 defunciones (2.2 por ciento) relacionadas directamente con la magnitud del suceso quirúrgico, la presencia de enfermedades subyacentes y la suma de complicaciones postoperatorias. La selección de pruebas de laboratorio y gabinetes, para llevar a cabo la valoración clínica, la cual debe enfocarse a la búsqueda de factores de riesgo para complicaciones del acto quirúrgico