Human-Centered Computer Vision

Contains fulltext : 241512.pdf (Publisher’s version ) (Open Access)Symposium on The Art and Science of Pattern Recognitio

Computer-aided detection of pulmonary nodules: a comparative study using the public LIDC/IDRI database

Objectives: To benchmark the performance of state-of-the-art computer-aided detection (CAD) of pulmonary nodules using the largest publicly available annotated CT database (LIDC/IDRI), and to show that CAD finds lesions not identified by the LIDC’s four-fold double reading process. Methods: The LIDC/IDRI database contains 888 thoracic CT scans with a section thickness of 2.5 mm or lower. We report performance of two commercial and one academic CAD system. The influence of presence of contrast, section thickness, and reconstruction kernel on CAD performance was assessed. Four radiologists independently analyzed the false positive CAD marks of the best CAD system. Results: The updated commercial CAD system showed the best performance with a sensitivity of 82 % at an average of 3.1 false positive detections per scan. Forty-five false positive CAD marks were scored as nodules by all four radiologists in our study. Conclusions: On the largest publicly available reference database for lung nodule detection in chest CT, the updated commercial CAD system locates the vast majority of pulmonary nodules at a low false positive rate. Potential for CAD is substantiated by the fact that it identifies pulmonary nodules that were not marked during the extensive four-fold LIDC annotation process

Bronchoscopic Lung Volume Reduction Treatment Using Endobronchial Valves for Emphysema:Emerging Questions

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HRCT characteristics of severe emphysema patients:Interobserver variability among expert readers and comparison with quantitative software

PURPOSE: For a successful bronchoscopic lung volume reduction coil treatment it is important to place the coils in the most emphysematous lobes. Therefore assessment of the lobe with greatest destruction is essential. Our aims were to investigate the level of agreement among expert reviewers of HRCT-scans in emphysema patients and the comparison with QCT (quantitative computed tomography) software. METHOD: Five experienced CT-assessors, conducted a visual assessment of the baseline HRCT-scans of emphysema patients who participated in the RENEW bronchoscopic lung volume reduction coil study. On the same HRCT-scans, a QCT analysis was performed. RESULTS: In total 134 HRCT-scans were rated by all 5 experts. All 5 CT-assessors agreed on which was the most destructed lobe in 61 % of the left lungs (k:0.459) and 60 % of the right lungs (k:0.370). The consensus of the 5 assessors matched the QCT in the left lung for 77 % of the patients (k:0.425) and in the right lung for 82 % (k:0.524). CONCLUSIONS: Our results show that the interobserver agreement between five expert CT-assessors was only fair to moderate when evaluating the most destructed lobe. CT-assessor consensus improved matching with QCT determination of lobar destruction compared to individual assessor determinations. Because some CT-features are associated with treatment outcomes and important for optimal patient selection of bronchoscopic lung volume reduction treatment, we recommend including more than one CT-reviewer and supported by QCT measurements

Chartis Measurement of Collateral Ventilation:Conscious Sedation versus General Anesthesia

BACKGROUND: Absence of interlobar collateral ventilation using the Chartis measurement is the key predictor for successful endobronchial valve treatment in severe emphysema. Chartis was originally validated in spontaneous breathing patients under conscious sedation (CS); however, this can be challenging due to cough, mucus secretion, mucosal swelling, and bronchoconstriction. Performing Chartis under general anesthesia (GA) avoids these problems and may result in an easier procedure with a higher success rate. However, using Chartis under GA with positive pressure ventilation has not been validated. OBJECTIVES: In this study we investigated the impact of anesthesia technique, CS versus GA, on the feasibility and outcomes of Chartis measurement. METHODS: We retrospectively analyzed all Chartis measurements performed at our hospital from October 2010 until December 2017. RESULTS: We analyzed 250 emphysema patients (median forced expiratory volume in 1 s 26%, range 12-52% predicted). In 121 patients (48%) the measurement was performed using CS, in 124 (50%) using GA, and in 5 (2%) both anesthesia techniques were used. In total, 746 Chartis readings were analyzed (432 CS, 277 GA, and 37 combination). Testing under CS took significantly longer than GA (median 19 min [range 5-65] vs. 11 min [3-35], p < 0.001) and required more measurements (3 [1-13] vs. 2 [1-6], p < 0.001). There was no significant difference in target lobe volume reduction after treatment (-1,123 mL [-3,604 to 332] in CS vs. -1,251 mL [-3,333 to -1] in GA, p = 0.35). CONCLUSIONS: In conclusion, Chartis measurement under CS took significantly longer and required more measurements than under GA, without a difference in treatment outcome. We recommend a prospective trial comparing both techniques within the same patients to validate this approach

A New Oxygen Uptake Measurement Supporting Target Selection for Endobronchial Valve Treatment

BACKGROUND: Adequate target lobe selection for endobronchial valve (EBV) treatment in patients with severe emphysema is essential for treatment success and can be based on emphysema destruction, lobar perfusion, lobar volume, and collateral ventilation. As some patients have >1 target lobe for EBV treatment, we were interested whether we could identify the least functional lobe. OBJECTIVES: The objective of this study was to investigate the relationship between endoscopic lobar measurement of oxygen uptake, lobar destruction, and vascular volume, and whether this could help in identifying the least functional lobe and thus optimal target for EBV treatment. METHOD: We prospectively included patients who were scheduled for EBV treatment in our hospital. A customized gas analysis setup was used to measure lobar O2 uptake after lobar balloon occlusion. Quantitative CT analysis was performed to assess the degree of emphysematous destruction and lobar arterial and venous volumes. RESULTS: Twenty-one (5 male/16 female) patients with emphysema (median age 63 years, FEV1 25% of predicted, residual volume 234% of predicted) were included, and 49 endoscopic lobar measurements were performed. A lower O2 uptake significantly correlated with a higher degree of emphysematous lobar destruction (Spearman's ρ: 0.39, p < 0.01), and lower arterial and venous vascular volumes of the lobes (-0.46 and -0.47, respectively; both p < 0.001). CONCLUSIONS: Endoscopic measurement of lobar O2 uptake is feasible in patients with emphysema. Measurement of lobar O2 uptake helped to identify the least functional lobe and can be used as additional tool for EBV target lobe selection

Obstructive pulmonary disease in patients with previous tuberculosis: Pathophysiology of a community-based cohort

Background. An association between chronic airflow limitation (CAL) and a history of pulmonary tuberculosis (PTB) has been confirmed in epidemiological studies, but the mechanisms responsible for this association are unclear. It is debated whether CAL in this context should be viewed as chronic obstructive pulmonary disease (COPD) or a separate phenotype. Objective. To compare lung physiology and high-resolution computed tomography (HRCT) findings in subjects with CAL and evidence of previous (healed) PTB with those in subjects with smoking-related COPD without evidence of previous PTB. Methods. Subjects with CAL identified during a Burden of Obstructive Lung Disease (BOLD) study performed in South Africa were studied. Investigations included questionnaires, lung physiology (spirometry, body plethysmography and diffusing capacity) and quantitative HRCT scans to assess bronchial anatomy and the presence of emphysema (–200 HU). Findings in subjects with a past history and/or HRCT evidence of PTB were compared with those in subjects without these features. Results. One hundred and seven of 196 eligible subjects (54.6%) were enrolled, 104 performed physiology tests and 94 had an HRCT scan. Based on history and HRCT findings, subjects were categorised as no previous PTB (NPTB, n=31), probable previous PTB (n=33) or definite previous PTB (DPTB, n=39). Subjects with DPTB had a lower diffusing capacity (Δ=–17.7%; p=0.001) and inspiratory capacity (Δ=–21.5%; p=0.001) than NPTB subjects, and higher gas-trapping and fibrosis but not emphysema scores (Δ=+6.2% (p=0.021), +0.36% (p=0.017) and +3.5% (p=0.098), respectively). Conclusions. The mechanisms of CAL associated with previous PTB appear to differ from those in the more common smoking-related COPD and warrant further study..info:eu-repo/semantics/publishedVersio

Obstructive pulmonary disease in patients with previous tuberculosis: Pathophysiology of a community-based cohort

Background. An association between chronic airflow limitation (CAL) and a history of pulmonary tuberculosis (PTB) has been confirmed in epidemiological studies, but the mechanisms responsible for this association are unclear. It is debated whether CAL in this context should be viewed as chronic obstructive pulmonary disease (COPD) or a separate phenotype.Objective. To compare lung physiology and high-resolution computed tomography (HRCT) findings in subjects with CAL and evidence of previous (healed) PTB with those in subjects with smoking-related COPD without evidence of previous PTB.Methods. Subjects with CAL identified during a Burden of Obstructive Lung Disease (BOLD) study performed in South Africa were studied. Investigations included questionnaires, lung physiology (spirometry, body plethysmography and diffusing capacity) and quantitative HRCT scans to assess bronchial anatomy and the presence of emphysema (&lt;–950 HU), gas trapping (&lt;–860 HU) and fibrosis (&gt;–200 HU). Findings in subjects with a past history and/or HRCT evidence of PTB were compared with those in subjects without these features.Results. One hundred and seven of 196 eligible subjects (54.6%) were enrolled, 104 performed physiology tests and 94 had an HRCT scan. Based on history and HRCT findings, subjects were categorised as no previous PTB (NPTB, n=31), probable previous PTB (n=33) or definite previous PTB (DPTB, n=39). Subjects with DPTB had a lower diffusing capacity (Δ=–17.7%; p=0.001) and inspiratory capacity (Δ=–21.5%; p=0.001) than NPTB subjects, and higher gas-trapping and fibrosis but not emphysema scores (Δ=+6.2% (p=0.021), +0.36% (p=0.017) and +3.5% (p=0.098), respectively).Conclusions. The mechanisms of CAL associated with previous PTB appear to differ from those in the more common smoking-related COPD and warrant further study

Data harmonisation for information fusion in digital healthcare: A state-of-the-art systematic review, meta-analysis and future research directions.

Removing the bias and variance of multicentre data has always been a challenge in large scale digital healthcare studies, which requires the ability to integrate clinical features extracted from data acquired by different scanners and protocols to improve stability and robustness. Previous studies have described various computational approaches to fuse single modality multicentre datasets. However, these surveys rarely focused on evaluation metrics and lacked a checklist for computational data harmonisation studies. In this systematic review, we summarise the computational data harmonisation approaches for multi-modality data in the digital healthcare field, including harmonisation strategies and evaluation metrics based on different theories. In addition, a comprehensive checklist that summarises common practices for data harmonisation studies is proposed to guide researchers to report their research findings more effectively. Last but not least, flowcharts presenting possible ways for methodology and metric selection are proposed and the limitations of different methods have been surveyed for future research