Subclinical synovitis by ultrasound is a frequent finding in rheumatoid arthritis (RA) patients in remission and has been shown to be related to erosive progression, risk of flare and unsuccessful ...drug tapering, but it has not been investigated how a DAS28 T2T-steered strategy in routine care affects the presence of subclinical synovitis in RA patients in remission. The aim of the current study was to investigate the presence of ultrasound-detected subclinical inflammation in RA patients in long-term remission receiving either biological or conventional disease-modifying anti-rheumatic drugs (bDMARD/csDMARD) and, finally, to investigate the presence of ultrasound remission using different ultrasound remission criteria.
Eighty-seven RA patients (42 patients receiving bDMARD and 45 csDMARD) received DAS28-CRP-steered treatment in routine care and had achieved DAS28-CRP-remission for > 1 year without radiographic progression. Twenty-four joints were scored 0-3 by ultrasound (elbows, wrists, knees, ankles, metacarpophalangeal and metatarsophalangeal joints 2-5) for grey-scale synovial hypertrophy (GS) and colour Doppler activity (CD) using the OMERACT scoring system. Ultrasound remission was defined as strict (GS score = 0 and CD score = 0), semi-strict (GS score < 1 and Doppler score = 0) and Doppler remission (Doppler score = 0).
No differences between treatment groups were found for GS sum score and Doppler sum score (median (range) 6 (0-19) and 0 (0-12), respectively). A Doppler score > 0 in at least 1 joint was seen in 44%, a GS score > 1 in at least 1 joint in 93% and a GS score > 2 in at least 1 joint in 54% of patients. Strict ultrasound remission was only observed in bDMARD patients (7%; p = 0.01). Thirty-seven per cent were in semi-strict ultrasound remission and 56% in Doppler remission (no significant difference between groups) with similar results across the subgroups of patients who also fulfilled the ACR-EULAR Boolean-, CDAI- and SDAI-remission criteria.
Ultrasound frequently detected subclinical synovitis in RA patients in longstanding DAS28-remission obtained through a DAS28-CRP-steered strategy. This was independent of treatment and applied ultrasound remission criteria. Strict ultrasound remission was rare.
To assess the ability of ultrasound to predict successful tapering and successful discontinuation of biological DMARDs (bDMARDs) at the 2-year follow-up in RA patients in sustained remission.
...Patients in sustained remission (DAS28-CRP ≤ 2.6) and with no radiographic progression the previous year tapered bDMARDs according to a standardized regime. A total of 119 of these patients were included in this ultrasound substudy. At baseline, clinical assessment, MRI, X-ray and ultrasound of 24 joints were performed. Ultrasound-detected synovitis was defined and scored 0-3 using the OMERACT scoring system at the joint level for both grey-scale and Doppler activity. Sum scores for each ultrasound modality were calculated for 24 joints at the patient level. The final state of treatment was assessed after 2 years. The predictive value of ultrasound measures for successful tapering and discontinuation at the 2-year follow-up was assessed via logistic regression analyses.
Negative IgM-RF odds ratio (OR) = 0.29, 95% CI: 0.10-0.85; P = 0.024 and lower Doppler sum score of 24 joints (OR = 0.44, 95% CI: 0.15, 0.87; P = 0.014) were independent predictors for successful discontinuation of bDMARDs at the 2-year follow-up. The predictive value of the Doppler sum score was independent of MRI findings. Previous numbers of bDMARDs were predictive of successful tapering (OR = 0.58, 95% CI: 0.35, 0.91; P = 0.018), whereas ultrasound was not. Clinical parameters were not predictive of successful tapering/discontinuation.
Doppler sum score was an independent predictor for successful discontinuation of bDMARDs at the 2-year follow-up-the odds for achieving successful discontinuation decreased by 56% per one-unit increase in Doppler sum score. Ultrasound could not predict successful tapering.
Field-to-susceptibility inversion in quantitative susceptibility mapping (QSM) is ill-posed and needs numerical stabilization through either regularization or oversampling by acquiring data at three ...or more object orientations. Calculation Of Susceptibility through Multiple Orientations Sampling (COSMOS) is an established oversampling approach and regarded as QSM gold standard. It achieves a well-conditioned inverse problem, requiring rotations by 0°, 60° and 120° in the yz-plane. However, this is impractical in vivo, where head rotations are typically restricted to a range of ±25°. Non-ideal sampling degrades the conditioning with residual streaking artifacts whose mitigation needs further regularization. Moreover, susceptibility anisotropy in white matter is not considered in the COSMOS model, which may introduce additional bias. The current work presents a thorough investigation of these effects in primate brain.
Gradient-recalled echo (GRE) data of an entire fixed chimpanzee brain were acquired at 7 T (350 μm resolution, 10 orientations) including ideal COSMOS sampling and realistic rotations in vivo. Comparisons of the results included ideal COSMOS, in-vivo feasible acquisitions with 3–8 orientations and single-orientation iLSQR QSM.
In-vivo feasible and optimal COSMOS yielded high-quality susceptibility maps with increased SNR resulting from averaging multiple acquisitions. COSMOS reconstructions from non-ideal rotations about a single axis required additional L2-regularization to mitigate residual streaking artifacts.
In view of unconsidered anisotropy effects, added complexity of the reconstruction, and the general challenge of multi-orientation acquisitions, advantages of sub-optimal COSMOS schemes over regularized single-orientation QSM appear limited in in-vivo settings.
Graphics artists commonly employ physically-based simulation for the generation of effects such as smoke, explosions, and similar phenomena. The task of finding the correct parameters for a desired ...result, however, is difficult and time-consuming as current tools provide little to no guidance. In this paper, we present a new approach for the visual exploration of such parameter spaces. Given a three-dimensional scene description, we utilize sampling and spatio-temporal clustering techniques to generate a concise overview of the achievable variations and their temporal evolution. Our visualization system then allows the user to explore the simulation space in a goal-oriented manner. Animation sequences with a set of desired characteristics can be composed using a novel search-by-example approach and interactive direct volume rendering is employed to provide instant visual feedback.
We present an assessment of the state and historic development of evaluation practices as reported in papers published at the IEEE Visualization conference. Our goal is to reflect on a meta-level ...about evaluation in our community through a systematic understanding of the characteristics and goals of presented evaluations. For this purpose we conducted a systematic review of ten years of evaluations in the published papers using and extending a coding scheme previously established by Lam et al. 2012. The results of our review include an overview of the most common evaluation goals in the community, how they evolved over time, and how they contrast or align to those of the IEEE Information Visualization conference. In particular, we found that evaluations specific to assessing resulting images and algorithm performance are the most prevalent (with consistently 80-90% of all papers since 1997). However, especially over the last six years there is a steady increase in evaluation methods that include participants, either by evaluating their performances and subjective feedback or by evaluating their work practices and their improved analysis and reasoning capabilities using visual tools. Up to 2010, this trend in the IEEE Visualization conference was much more pronounced than in the IEEE Information Visualization conference which only showed an increasing percentage of evaluation through user performance and experience testing. Since 2011, however, also papers in IEEE Information Visualization show such an increase of evaluations of work practices and analysis as well as reasoning using visual tools. Further, we found that generally the studies reporting requirements analyses and domain-specific work practices are too informally reported which hinders cross-comparison and lowers external validity.
To identify predictors of flare in a 2-year follow-up study of patients with rheumatoid arthritis (RA) in sustained clinical remission tapering towards withdrawal of biological disease-modifying ...anti-rheumatic drugs (bDMARDs).
Sustained clinical remission was defined as Disease Activity Score for 28 joints (DAS28)-C reactive protein (CRP) ≤2.6 without radiographic progression for >1 year. bDMARDs were tapered according to a mandatory clinical guideline to two-thirds of standard dose at baseline, half of dose at week 16 and discontinuation at week 32. Prospective assessments for 2 years included clinical evaluation, conventional radiography, ultrasound and MRI for signs of inflammation and bone changes. Flare was defined as DAS28-CRP ≥2.6 with ∆DAS28-CRP ≥1.2 from baseline. Baseline predictors of flare were assessed by logistic regression analyses.
Of 142 included patients, 121 (85%) flared during follow-up of which 86% regained remission within 24 weeks after flare. Patients that flared were more often rheumatoid factor positive, had tried more bDMARDs and had higher baseline ultrasound synovitis sum scores than those not flaring. For patients on standard dose, predictors of flare within 16 weeks after reduction to two-thirds of standard dose were baseline MRI-osteitis (OR 1.16; 95% CI 1.03 to 1.33; p=0.014), gender (female) (OR 6.71; 95% CI 1.68 to 46.12; p=0.005) and disease duration (OR 1.06; 95% CI 1.01 to 1.11; p=0.020). Baseline predictors for flare within 2 years were ultrasound grey scale synovitis sum score (OR 1.19; 95% CI 1.02 to 1.44; p=0.020) and number of previous bDMARDs (OR 4.07; 95% CI 1.35 to 24.72; p=0.007).
The majority of real-world patients with RA tapering bDMARDs flared during tapering, with the majority regaining remission after stepwise dose increase. Demographic and imaging parameters (MR-osteitis/ultrasound greyscale synovitis) were independent predictors of immediate flare and flare overall and may be of importance for clinical decision-making in patients eligible for tapering.
Data visualizations play a critical role in both communicating scientific evidence about climate change and in stimulating engagement and action. To investigate how visualizations can be better ...utilized to communicate the complexities of climate change to different audiences, we conducted interviews with 17 experts in the fields of climate change, data visualization, and science communication, as well as with 12 laypersons. Besides questions about climate change communication and various aspects of data visualizations, we also asked participants to share what they think is the main takeaway message for two exemplary climate change data visualizations. Through a thematic analysis, we observe differences regarding the included contents, the length and abstraction of messages, and the sensemaking process between and among the participant groups. On average, experts formulated shorter and more abstract messages, often referring to higher-level conclusions rather than specific details. We use our findings to reflect on design decisions for creating more effective visualizations, particularly in news media sources geared toward lay audiences. We hereby discuss the adaption of contents according to the needs of the audience, the trade-off between simplification and accuracy, as well as techniques to make a visualization attractive.
Various case studies in different application domains have shown the great potential of visual parameter space analysis to support validating and using simulation models. In order to guide and ...systematize research endeavors in this area, we provide a conceptual framework for visual parameter space analysis problems. The framework is based on our own experience and a structured analysis of the visualization literature. It contains three major components: (1) a data flow model that helps to abstractly describe visual parameter space analysis problems independent of their application domain; (2) a set of four navigation strategies of how parameter space analysis can be supported by visualization tools; and (3) a characterization of six analysis tasks. Based on our framework, we analyze and classify the current body of literature, and identify three open research gaps in visual parameter space analysis. The framework and its discussion are meant to support visualization designers and researchers in characterizing parameter space analysis problems and to guide their design and evaluation processes.
Balancing accuracy gains with other objectives such as interpretability is a key challenge when building decision trees. However, this process is difficult to automate because it involves know-how ...about the domain as well as the purpose of the model. This paper presents TreePOD, a new approach for sensitivity-aware model selection along trade-offs. TreePOD is based on exploring a large set of candidate trees generated by sampling the parameters of tree construction algorithms. Based on this set, visualizations of quantitative and qualitative tree aspects provide a comprehensive overview of possible tree characteristics. Along trade-offs between two objectives, TreePOD provides efficient selection guidance by focusing on Pareto-optimal tree candidates. TreePOD also conveys the sensitivities of tree characteristics on variations of selected parameters by extending the tree generation process with a full-factorial sampling. We demonstrate how TreePOD supports a variety of tasks involved in decision tree selection and describe its integration in a holistic workflow for building and selecting decision trees. For evaluation, we illustrate a case study for predicting critical power grid states, and we report qualitative feedback from domain experts in the energy sector. This feedback suggests that TreePOD enables users with and without statistical background a confident and efficient identification of suitable decision trees.
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