Objective: Hyperpolarized noble gas magnetic resonance imaging (MRI) provides valuable insights on lung function, and yet is not widely available, whereas thoracic x-ray computed tomography (CT) protocols are nearly universally accessible. Our aim was to develop a texture analysis pipeline to train and test machine learning classifiers, predicting MRI-based ventilation metrics from single-volume thoracic CT in patients with chronic obstructive pulmonary disease (COPD). Methods: MR ventilation maps were generated and registered to thoracic CT datasets. Images were segmented into volumes of interest (15x15x15mm), resulting in approximately 6,000 volumes-of-interest per subject participant. 85 firstorder and texture features were calculated to describe each volume, including a new texture feature based on the size and occurrence of CT clusters (we called the cluster volume matrix), which is similar to run-length-matrix. A Logistic Regression, Linear Support Vector Machine and Quadratic Support Vector Machine were trained using 5-fold crossvalidation on a cohort of seven subjects. The highest performing classification model was then applied to a test cohort of three subjects. Results: There was qualitative spatial agreement for the experimental MRI ventilation maps and the CT-predicted functional maps. The training set was classified with 71% accuracy, while the test set was classified with 66% accuracy and area under the curve (AUC) = 0.72. Conclusions: This proof-of-concept study demonstrated feasibility in a small group of patients with moderate classification accuracy. Novel insights will be used to optimize this approach with future application to a larger heterogeneous patient cohort.
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