Usefulness of CT texture analysis in differentiating benign and malignant renal tumours

AIM

To elucidate visually imperceptible differences between benign and malignant renal tumours using computed tomography texture analysis (CTTA) using filtration histogram based parameters.

MATERIALS AND METHODS

A retrospective study was performed by texture analysis of pretreatment contrast-enhanced CT examinations in 354 histopathologically confirmed renal cell carcinomas (RCCs) and 147 benign renal tumours. A region-of-interest was drawn encompassing the largest cross-section of the tumour on venous phase axial CT. CTTA features of entropy, kurtosis, mean positive pixel density, and skewness at different spatial filters were calculated and compared in an attempt to differentiate benign lesions from malignancy.

RESULTS

Entropy with fine spatial filter was significantly higher in RCC than benign renal tumours (p=0.022). Entropy with fine and medium filters was higher in RCC than lipid-poor angiomyolipoma (p=0.050 and 0.052, respectively). Entropy >5.62 had high specificity of 85.7%, but low sensitivity of 31.3%, respectively, for predicting RCC.

CONCLUSIONS

Differences in entropy were helpful in differentiating RCC from lipid-poor angiomyolipoma, and chromophobe RCC from oncocytoma. This technique may be useful to differentiate lesions that appear equivocal on visual assessment or alter management in poor surgical candidates.

Osteonecrosis and osteomyelitis of the jaw associated with tumour necrosis factor-alpha (TNF-α) inhibitors: a systematic review

Tumour necrosis factor-α (TNF-α) inhibitors are increasingly being used as immunomodulators to manage inflammatory conditions such as rheumatoid arthritis and Crohn's disease. Reported serious side effects include an increased incidence of lymphoma and greater susceptibility to infections such as tuberculosis. The aim of this systematic review was to find out whether there is an associated risk of medication-related osteonecrosis of the jaw (MRONJ). Three authors independently searched PubMed, MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials for published reports of oral osteonecrosis (ONJ) or osteomyelitis (OM) in patients who took anti TNF-α drugs and had no history of antiangiogenic agents or antiresorptive treatment. All types of studies on humans treated with TNF-α inhibitors were considered. Only six were eligible for analysis, and all were independently assessed for risk of bias. They included six patients with ONJ or OM that was attributed solely to TNF-α inhibitors. The most common site of ONJ was the posterior mandible (n=5). The mean (SD) duration of anti-TNF-α treatment before the development of bony lesions was 62.5 (47.4) months. Invasive surgery was reported as a precipitating factor in five cases, and the ONJ/OM resolved with conservative management in five. Although all the studies were judged to be at high risk of bias, the limited data suggest that some patients will potentially develop ONJ/OM as a result of treatment with TNF-α inhibitors. Studies of higher quality are now needed to establish the relative risk of MRONJ in patients who take them.

P1861Influence of thermal conductivity on esophageal protection with a cooling device during high-power short-duration radiofrequency ablation

Introduction

Recent clinical data show that high-power, short-duration (HPSD) radiofrequency (RF) ablation can result in a similar esophageal injury rate as traditional low-power, long-duration (LPLD) ablation. Existing methods to prevent esophageal injury have yielded mixed results and can result in prolonged procedure time, potentially increasing the incidence of post-operative cognitive dysfunction. A new esophageal cooling device currently available for whole-body temperature modulation is being studied for the prevention of esophageal injury during LPLD RF ablation and cryoablation. We sought to develop a mathematical model of HPSD ablation in order to quantify the capability of this new esophageal cooling device to protect from esophageal injury under high-power conditions.

Methods

Using a model we developed of HPSD RF ablation in the left atrium, we measured the change in esophageal lesion formation and the depth of lesions (measured as percent transmurality) with the esophageal cooling device in place and operating at a temperature from 5°C to 37°C. Tissue parameters, including thermal conductivity, were set to average values obtained from existing literature, and energy settings were evaluated at 50W for between 5 and 10 seconds, and at 90W for a duration of 4 seconds.

Results

Esophageal injury as measured by percent transmurality was considerably higher at 50W and 10s duration than at 90W of power with 4s duration, although both settings showed potential for esophageal injury. The protective effect of the esophageal cooling device was evident for both cases, with a greater effect when using 50W for 10s (Figure 1). At the coldest device settings, using a 5 min pre-cooling period also reduced the transmurality of the intended atrial lesions.

Esophageal protection in HPSD ablation

Conclusions

Esophageal cooling with a new patient temperature management device shows protective effects against thermal injury during RF ablation across a range of tissue thermal conductivity, using a variety of high-power settings, including 90W applied for 4 seconds. Adjusting the cooling power by adjusting the circulating water temperature in the device allows for a tailoring of the protective effects to operating conditions.

Acknowledgement/Funding

Attune Medical

Smartphone geospatial apps for dengue control, prevention, prediction, and education: MOSapp, DISapp, and the mosquito perception index (MPI)

India has the largest number of dengue cases in the world, contributing approximately 34% of the global burden. The framework for a geospatially enabled early warning and adaptive response system (EWARS) was first proposed in 2008. It was meant to be a decision support system for enhancing traditional surveillance methods for preventing mosquito-borne diseases in India by utilizing remote sensing data and fuzzy logic-based mathematical predictive modeling. This conceptual paper presents a significant evolution of EWARS such that it synthesizes inputs from not only traditional surveillance and reporting systems for dengue but also from the public via participatory disease surveillance. Two smartphone-based applications have been developed to support EWARS. The first-MOSapp-allows field health workers to upload surveillance data and collect key data on environmental parameters by both direct observation and via portable microclimate stations. The second-DISapp-collects relevant information directly from the community to support participatory disease surveillance. It also gives the user a real-time estimate of the risk of exposure to dengue in proximity to their home and has an educational component that provides information on relevant preventive measures. Both applications utilize a new mosquito abundance measure-the mosquito perception index (MPI)-as reported by the user. These data streams will feed into the EWARS model to generate dynamic risk maps that can guide resource optimization and strengthen disease surveillance, prevention, and response. It is anticipated that such an approach can assist in addressing gaps in the current system of dengue surveillance and control in India.

Fungal Planet description sheets: 868-950

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetomella pseudocircinoseta and Coniella pseudodiospyri on Eucalyptus microcorys leaves, Cladophialophora eucalypti, Teratosphaeria dunnii and Vermiculariopsiella dunnii on Eucalyptus dunnii leaves, Cylindrium grande and Hypsotheca eucalyptorum on Eucalyptus grandis leaves, Elsinoe salignae on Eucalyptus saligna leaves, Marasmius lebeliae on litter of regenerating subtropical rainforest, Phialoseptomonium eucalypti (incl. Phialoseptomonium gen. nov.) on Eucalyptus grandis × camaldulensis leaves, Phlogicylindrium pawpawense on Eucalyptus tereticornis leaves, Phyllosticta longicauda as an endophyte from healthy Eustrephus latifolius leaves, Pseudosydowia eucalyptorum on Eucalyptus sp. leaves, Saitozyma wallum on Banksia aemula leaves, Teratosphaeria henryi on Corymbia henryi leaves. Brazil, Aspergillus bezerrae, Backusella azygospora, Mariannaea terricola and Talaromyces pernambucoensis from soil, Calonectria matogrossensis on Eucalyptus urophylla leaves, Calvatia brasiliensis on soil, Carcinomyces nordestinensis on Bromelia antiacantha leaves, Dendryphiella stromaticola on small branches of an unidentified plant, Nigrospora brasiliensis on Nopalea cochenillifera leaves, Penicillium alagoense as a leaf endophyte on a Miconia sp., Podosordaria nigrobrunnea on dung, Spegazzinia bromeliacearum as a leaf endophyte on Tilandsia catimbauensis, Xylobolus brasiliensis on decaying wood. Bulgaria, Kazachstania molopis from the gut of the beetle Molops piceus. Croatia, Mollisia endocrystallina from a fallen decorticated Picea abies tree trunk. Ecuador, Hygrocybe rodomaculata on soil. Hungary, Alfoldia vorosii (incl. Alfoldia gen. nov.) from Juniperus communis roots, Kiskunsagia ubrizsyi (incl. Kiskunsagia gen. nov.) from Fumana procumbens roots. India, Aureobasidium tremulum as laboratory contaminant, Leucosporidium himalayensis and Naganishia indica from windblown dust on glaciers. Italy, Neodevriesia cycadicola on Cycas sp. leaves, Pseudocercospora pseudomyrticola on Myrtus communis leaves, Ramularia pistaciae on Pistacia lentiscus leaves, Neognomoniopsis quercina (incl. Neognomoniopsis gen. nov.) on Quercus ilex leaves. Japan, Diaporthe fructicola on Passiflora edulis × P. edulis f. flavicarpa fruit, Entoloma nipponicum on leaf litter in a mixed Cryptomeria japonica and Acer spp. forest. Macedonia, Astraeus macedonicus on soil. Malaysia, Fusicladium eucalyptigenum on Eucalyptus sp. twigs, Neoacrodontiella eucalypti (incl. Neoacrodontiella gen. nov.) on Eucalyptus urophylla leaves. Mozambique, Meliola gorongosensis on dead Philenoptera violacea leaflets. Nepal, Coniochaeta dendrobiicola from Dendriobium lognicornu roots. New Zealand, Neodevriesia sexualis and Thozetella neonivea on Archontophoenix cunninghamiana leaves. Norway, Calophoma sandfjordenica from a piece of board on a rocky shoreline, Clavaria parvispora on soil, Didymella finnmarkica from a piece of Pinus sylvestris driftwood. Poland, Sugiyamaella trypani from soil. Portugal, Colletotrichum feijoicola from Acca sellowiana. Russia, Crepidotus tobolensis on Populus tremula debris, Entoloma ekaterinae, Entoloma erhardii and Suillus gastroflavus on soil, Nakazawaea ambrosiae from the galleries of Ips typographus under the bark of Picea abies. Slovenia, Pluteus ludwigii on twigs of broadleaved trees. South Africa, Anungitiomyces stellenboschiensis (incl. Anungitiomyces gen. nov.) and Niesslia stellenboschiana on Eucalyptus sp. leaves, Beltraniella pseudoportoricensis on Podocarpus falcatus leaf litter, Corynespora encephalarti on Encephalartos sp. leaves, Cytospora pavettae on Pavetta revoluta leaves, Helminthosporium erythrinicola on Erythrina humeana leaves, Helminthosporium syzygii on a Syzygium sp. bark canker, Libertasomyces aloeticus on Aloe sp. leaves, Penicillium lunae from Musa sp. fruit, Phyllosticta lauridiae on Lauridia tetragona leaves, Pseudotruncatella bolusanthi (incl. Pseudotruncatellaceae fam. nov.) and Dactylella bolusanthi on Bolusanthus speciosus leaves. Spain, Apenidiella foetida on submerged plant debris, Inocybe grammatoides on Quercus ilex subsp. ilex forest humus, Ossicaulis salomii on soil, Phialemonium guarroi from soil. Thailand, Pantospora chromolaenae on Chromolaena odorata leaves. Ukraine, Cadophora helianthi from Helianthus annuus stems. USA, Boletus pseudopinophilus on soil under slash pine, Botryotrichum foricae, Penicillium americanum and Penicillium minnesotense from air. Vietnam, Lycoperdon vietnamense on soil. Morphological and culture characteristics are supported by DNA barcodes.

Influence of learning-style preferences in academic performance in the subject of human anatomy: an institution-based study among preclinical medical students

Purpose: The present study was conducted to find the preferred mode of learning among first-year preclinical students and compare the preferred mode of learning with sex, faculty of students, and academic performance of the students using the VARK questionnaire. Methods: A cross-sectional study was done among 142 first-year Bachelor of Medicine-Bachelor of Surgery and Bachelor of Dental Surgery students from February to May 2018. Demographic data and various academic performance marks were recorded for each individual. VARK (visual, aural, read/write and kinesthetic) questionnaire version 7.8 was administered to calculate the score of each component. Mean VARK scores were calculated and each student classified by their preferred mode of learning. The preferred mode of learning was compared with sex, nationality, faculty of students, and academic performance using χ ², unpaired t-tests, and the Mann-Whitney U test. P<0.05 was taken as statistically significant for comparison. Results: A majority of the students (53.52%) were multimodal. The most common multimodal mode of preference was bimodal (26.06%), while the most common unimodal preference was kinesthetic (29.06%). Total V score, K score, and VARK score were higher among males, while A and R scores were higher among females. The K score (7.96±2.35 in males and 6.96±2.43 in females) differed significantly (P=0.019) between male and female subjects. More subjects with higher scores in the theory exam of anatomy were unimodal learners (53.8%) compared to multimodal learners (46.2%). Conclusion: From this study, it can be concluded that undergraduate students were diverse in their learning styles, but most were multimodal. Though learning styles were found to vary by sex, nationality, and academic performance, differences were not statistically significant.