OLIVIA MEIRA DIAS
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/09 - Laboratório de Pneumologia, Hospital das Clínicas, Faculdade de Medicina
LIM/09 - Laboratório de Pneumologia, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
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- Texture-based classification of lung disease patterns in chronic hypersensitivity pneumonitis and comparison to clinical outcomes(2021) PENNATI, F.; ALIBONI, L.; ANTONIAZZA, A.; BERETTA, D.; DIAS, O.; BALDI, B. G.; SAWAMURA, M.; CHATE, R. C.; CARVALHO, C. R. R. De; ALBUQUERQUE, A.; ALIVERTI, A.Computer-aided detection algorithms applied to CT lung imaging have the potential to objectively quantify pulmonary pathology. We aim to develop an automatic classification method based on textural features able to classify healthy and pathological patterns on CT lung images and to quantify the extent of each disease pattern in a group of patients with chronic hypersensitivity pneumonitis (cHP), in comparison to pulmonary function tests (PFTs). 27 cHP patients were scanned via high resolution CT (HRCT) at full-inspiration. Regions of interest (ROIs) were extracted and labeled as normal (NOR), ground glass opacity (GGO), reticulation (RET), consolidation (C), honeycombing (HB) and air trapping (AT). For each ROI, statistical, morphological and fractal parameters were computed. For automatic classification, we compared two classification methods (Bayesian and Support Vector Machine) and three ROI sizes. The classifier was therefore applied to the overall CT images and the extent of each class was calculated and compared to PFTs. Better classification accuracy was found for the Bayesian classifier and the 16x16 ROI size: 92.1 +/- 2.7%. The extent of GGO, HB and NOR significantly correlated with forced vital capacity (FVC) and the extent of NOR with carbon monoxide diffusing capacity (DLCO).
- Mechanisms of exercise limitation in patients with chronic hypersensitivity pneumonitis(2018) DIAS, Olivia Meira; BALDI, Bruno Guedes; FERREIRA, Jeferson George; CARDENAS, Leticia Zumpano; PENNATI, Francesca; SALITO, Caterina; CARVALHO, Carlos Roberto Ribeiro; ALIVERTI, Andrea; ALBUQUERQUE, Andre Luis Pereira deSmall airway and interstitial pulmonary involvements are prominent in chronic hypersensitivity pneumonitis (cHP). However, their roles on exercise limitation and the relationship with functional lung tests have not been studied in detail. Our aim was to evaluate exercise performance and its determinants in cHP. We evaluated maximal cardiopulmonary exercise testing performance in 28 cHP patients (forced vital capacity 57 +/- 17% pred) and 18 healthy controls during cycling. Patients had reduced exercise performance with lower peak oxygen production (16.6 (12.3-19.98) mL.kg(-1).min(-1) versus 25.1 (16.9-32.0), p=0.003), diminished breathing reserve (% maximal voluntary ventilation) (12 (6.4-34.8)% versus 41 (32.7-50.8)%, p<0.001) and hyperventilation (minute ventilation/carbon dioxide production slope 37 +/- 5 versus 31 +/- 4, p<0.001). All patients presented oxygen desaturation and augmented Borg dyspnoea scores (8 (5-10) versus 4 (1-7), p=0.004). The prevalence of dynamic hyperinflation was found in only 18% of patients. When comparing cHP patients with normal and low peak oxygen production (<84% pred, lower limit of normal), the latter exhibited a higher minute ventilation/carbon dioxide production slope (39 +/- 5.0 versus 34 +/- 3.6, p=0.004), lower tidal volume (0.84 (0.78-0.90) L versus 1.15 (0.97-1.67) L, p=0.002), and poorer physical functioning score on the Short form-36 health survey. Receiver operating characteristic curve analysis showed that reduced lung volumes (forced vital capacity %, total lung capacity % and diffusing capacity of the lung for carbon dioxide %) were high predictors of poor exercise capacity. Reduced exercise capacity was prevalent in patients because of ventilatory limitation and not due to dynamic hyperinflation. Reduced lung volumes were reliable predictors of lower performance during exercise.