PurposeOur objective was to train machine-learning algorithms on hyperpolarized He3 magnetic resonance imaging (MRI) datasets to generate models of accelerated lung function decline in participants with and without chronic-obstructive-pulmonary-disease. We hypothesized that hyperpolarized gas MRI ventilation, machine-learning, and multivariate modeling could be combined to predict clinically-relevant changes in forced expiratory volume in 1 s (FEV1) across 3 years. ApproachHyperpolarized He3 MRI was acquired using a coronal Cartesian fast gradient recalled echo sequence with a partial echo and segmented using a k-means clustering algorithm. A maximum entropy mask was used to generate a region-of-interest for texture feature extraction using a custom-developed algorithm and the PyRadiomics platform. The principal component and Boruta analyses were used for feature selection. Ensemble-based and single machine-learning classifiers were evaluated using area-under-the-receiver-operator-curve and sensitivity-specificity analysis. ResultsWe evaluated 88 ex-smoker participants with 31±7 months follow-up data, 57 of whom (22 females/35 males, 70±9 years) had negligible changes in FEV1 and 31 participants (7 females/24 males, 68±9 years) with worsening FEV1≥60 mL/year. In addition, 3/88 ex-smokers reported a change in smoking status. We generated machine-learning models to predict FEV1 decline using demographics, spirometry, and texture features, with the later yielding the highest classification accuracy of 81%. The combined model (trained on all available measurements) achieved the overall best classification accuracy of 82%; however, it was not significantly different from the model trained on MRI texture features alone. ConclusionFor the first time, we have employed hyperpolarized He3 MRI ventilation texture features and machine-learning to identify ex-smokers with accelerated decline in FEV1 with 82% accuracy.
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