Web Accessibility for Visually Impaired Users: Extending the Technology Acceptance Model (TAM)

The Technology Acceptance Model (TAM) is one of the most widely used models in the MIS literature. Verified by many studies, TAM asserts that the perceived ease of use and perceived usefulness of an information technology is instrumental in its adoption. While previous research has been valuable in explaining how and why the perception of ease of use and usefulness develops, this research does not include a growing number of users, namely the disabled. The large number of disabled technology users calls for scientific examination of ways to improve technology acceptance and usage in this population. Our study will address this need by extending TAM to include visually disabled users. Moreover, our study will expand TAM by examining information accessibility as a potential key determinant of ease of use and usefulness of web usage for people with and without visual disability

18F-FDG PET-Derived Textural Indices Reflect Tissue-Specific Uptake Pattern in Non-Small Cell Lung Cancer

International audiencePurposeTexture indices (TI) calculated from 18F-FDG PET tumor images show promise for predicting response to therapy and survival. Their calculation involves a resampling of standardized uptake values (SUV) within the tumor. This resampling can be performed differently and significantly impacts the TI values. Our aim was to investigate how the resampling approach affects the ability of TI to reflect tissue-specific pattern of metabolic activity.Methods18F-FDG PET were acquired for 48 naïve-treatment patients with non-small cell lung cancer and for a uniform phantom. We studied 7 TI, SUVmax and metabolic volume (MV) in the phantom, tumors and healthy tissue using the usual relative resampling (RR) method and an absolute resampling (AR) method. The differences in TI values between tissue types and cancer subtypes were investigated using Wilcoxon’s tests.ResultsMost RR-based TI were highly correlated with MV for tumors less than 60 mL (Spearman correlation coefficient r between 0.74 and 1), while this correlation was reduced for AR-based TI (r between 0.06 and 0.27 except for RLNU where r = 0.91). Most AR-based TI were significantly different between tumor and healthy tissues (pvalues <0.01 for all 7 TI) and between cancer subtypes (pvalues<0.05 for 6 TI). Healthy tissue and adenocarcinomas exhibited more homogeneous texture than tumor tissue and squamous cell carcinomas respectively.ConclusionTI computed using an AR method vary as a function of the tissue type and cancer subtype more than the TI involving the usual RR method. AR-based TI might be useful for tumor characterization

Monitoring anti-PD-1-based immunotherapy in non-small cell lung cancer with FDG PET: introduction of iPERCIST

Abstract Background Immunotherapy represents a new therapeutic approach in non-small cell lung carcinoma (NSCLC) with the potential for prolonged benefits. Because of the systemic nature and heterogeneity of tumoral diseases, as well as the immune restoration process induced by immunotherapy, the assessment of therapeutic efficacy is challenging, and the role of FDG PET is not well established. We evaluated the potential of FDG PET to monitor NSCLC patients treated with a checkpoint inhibitor. Results This was a retrospective analysis of 28 NSCLC patients treated with nivolumab, a programmed cell death 1 (PD-1) blocker. All patients underwent a PET scan before treatment (SCAN-1) and another scan 2 months later (SCAN-2). Disease progression was assessed by immune PET Response Criteria in Solid Tumors (iPERCIST), which was adapted from PERCIST; and the immune Response Evaluation Criteria in Solid Tumors (iRECIST). iPERCIST is a dual-time-point evaluation of “unconfirmed progressive metabolic disease” (UPMD) status at SCAN-2. UPMD at SCAN-2 was re-evaluated after 4 weeks with SCAN-3 to confirm PMD. Patients with complete/partial metabolic response (CMR or PMR) or stable metabolic disease (SMD) at SCAN-2 or -3 were considered responders. Patients with UPMD confirmed at SCAN-3 were considered non-responders. The Kaplan-Meier method was used to estimate survival. At SCAN-2, we found 9/28 cases of PMR, 4/28 cases of SMD, 2/28 cases of CMR, and 13/28 cases of UPMD. Four of the 13 UPMD patients were classified as responders at SCAN-3 (PMR n = 1, SMD n = 3). The remaining nine UPMD patients were classified as non-responders due to clinical degradation, and treatment was stopped. The median follow-up was 16.7 months [3.6–32.2]. Responders continued treatment for a mean of 10.7 months [3.8–26.3]. Overall survival was longer for responders than that for non-responders (19.9 vs. 3.6 months, log rank p = 0.0003). The 1-year survival rates were 94% for responders and 11% for non-responders. A comparison with iRECIST showed reclassification in 39% (11/28) of patients with relevant additional prognostic information. Conclusions iPERCIST dual-time-point evaluation might be a powerful tool for evaluating anti-PD-1-based immunotherapy, with the ability to identify patients who can benefit most from treatment. The prognostic value of iPERCIST criteria should be confirmed in large prospective multicentric studies

Incidental focal solid liver lesions: diagnostic performance of contrast-enhanced ultrasound and MR imaging

International audienceObjective To prospectively assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) and MR imaging in incidental solid focal liver lesions not characterised on ultrasound. Materials and methods Forty-seven patients with 50 lesions underwent MR imaging and CEUS: 24 focal nodular hyperplasias (FNH), 11 adenomas, 10 haemangiomas, 1 focal fatty change and 4 malignant lesions were identified. Two experienced radiologists randomly reviewed contrast-enhanced MR imaging and CEUS data, and provided the most likely diagnosis. Sensitivity (Se), specificity (Sp), likelihood ratios (LR) and kappa value were calculated. Results A histotype diagnosis was obtained in 66–52% with MR imaging and 52–53% with CEUS, respectively, for both readers. Se, Sp and LR for haemangioma were 100–100, 100–100 and 78–78 with MR imaging and 89–89, 100–100 and 68–70 with CEUS; for FNH with MR imaging they were 88–63, 96–100 and 23–34 and 74–67, 88–96 and 6–17 with CEUS. If the diagnosis of haemangioma was uncertain with CEUS, MR imaging always confirmed the diagnosis. If the diagnosis of FNH was uncertain with either CEUS or MR imaging, the other imaging technique confirmed the diagnosis in approximately half the cases. Conclusion Both CEUS and MR imaging have a high diagnostic performance in incidental focal liver lesions and are complementary when diagnosis is uncertain.</p

Détection et segmentation de tumeurs cérébrales en imagerie hybride TEP-IRM

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Brain lesion detection in 3D PET images using max-trees and a new spatial context criterion

International audience<p>In this work, we propose a new criterion based on spatial context to select relevant nodes in a max-tree representation of an image, dedicated to the detection of 3D brain tumors for \textsuperscript{18}$F$-FDG PET images. This criterion prevents the detected lesions from merging with surrounding physiological radiotracer uptake. A complete detection method based on this criterion is proposed, and was evaluated on five patients with brain metastases and tuberculosis, and quantitatively assessed using the true positive rates and positive predictive values. The experimental results show that the method detects all the lesions in the PET.</p

Performance of the 2019 ESC/EASD guideline strategy for the screening of silent coronary artery disease in patients with diabetes

Abstract Background The 2019 guidelines for cardiovascular risk stratification by the European Society of Cardiology and European Association for the Study of Diabetes (ESC-EASD) suggested screening for silent coronary disease in very high risk patients with severe target organ damage (TOD) (i.e. peripheral occlusive arterial disease or severe nephropathy) or high coronary artery calcium (CAC) score. This study aimed to test the validity of this strategy. Methods In this retrospective study, we included 385 asymptomatic patients with diabetes and no history of coronary disease but with TOD or ≥ 3 risk factors in addition to diabetes. CAC score was measured using computed tomography scan and a stress myocardial scintigraphy was performed to detect silent myocardial ischemia (SMI), with subsequent coronary angiography in those with SMI. Various strategies to select patients to be screened for SMI were tested. Results CAC score was ≥ 100 Agatston units (AU) in 175 patients (45.5%). SMI was present in 39 patients (10.1%) and among the 30 patients who underwent angiography, 15 had coronary stenoses and 12 had a revascularization procedure. The most effective strategy consisted in performing myocardial scintigraphy in the 146 patients with severe TOD and, among the 239 other patients without severe TOD, in those with CAC ≥ 100 AU: this strategy provided 82% sensitivity for SMI diagnosis, and identified all the patients with stenoses. Conclusion The ESC-EASD guidelines suggesting SMI screening in asymptomatic patients with very high risk assessed by severe TOD or high CAC score appears effective and could identify all the patients with stenoses eligible for revascularization

Optimized multimodal nanoplatforms for targeting α(v)β3 integrins.

International audienceMagnetic Resonance Imaging (MRI) using contrast agents is a very powerful technique for diagnosis in clinical medicine and biomedical research. The synthesis of ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles targeting αvβ3 integrins and acting as new MRI contrast agents seems to be a promising way for cancer diagnosis. Indeed, it is well established that αvβ3 integrin plays a key role in tumor angiogenesis acting like a receptor for the extracellular matrix proteins like vitronectin, fibronectin through the arginine-glycine-aspartic acid (RGD) sequence. Up-regulation of αvβ3 has been found to be associated with a wide range of cancers, making it a broad-spectrum tumor-marker. In this study, USPIO nanocrystals were synthesized and surface passivated with caffeic acid. The large number of the carboxylic acid functions at the outer surface of the nanoplatforms was used for the covalent coupling of Rhodamine123, polyethylene glycol (PEG) and cyclic RGD. Soluble carbodiimide (EDC) and N-hydroxysuccinimide (NHS) were used to crosslink carboxylic acid with the amino group of the ligands. We examined the design of the nanoplatforms with each individual entity and then the combination of two and three of them. Several methods were used to characterize the nanoparticle surface functionalization and the magnetic properties of these contrast agents were studied using a 1.5 T clinical MRI scanner. The affinity towards integrins was evidenced by surface plasmon resonance and solid-phase receptor-binding assay