• Nanxi Zha, Damien Pike, Sarah Svenningsen, Capaldi Dante P I DP Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, ON N6A 5B7, Canada; Department of Medical Biophysics, , David G McCormack, and Grace Parraga.
• Imaging Research Laboratories, Robarts Research Institute, 1151 Richmond Street North, London, ON N6A 5B7, Canada.
• Acad Radiol. 2016 Feb 1; 23 (2): 176-85.

Rationale And Objectives(3)He magnetic resonance imaging (MRI) can be used to quantify functional responses to asthma therapy and provocation. Ventilation imaging offers quantitative information beyond ventilation defects that have not yet been exploited. Therefore, our objective was to evaluate hyperpolarized (3)He MRI ventilation defect percent (VDP) and compare this and pulmonary function measurements to ventilation image texture features and their changes post-bronchodilator administration in patients with asthma.Materials And MethodsVolunteers with a diagnosis of asthma provided written informed consent to an ethics board-approved protocol and underwent pulmonary function tests and MRI before and after salbutamol inhalation. MR images were analyzed using VDP, and their texture was evaluated via gray-level run-length matrices. These texture classifiers were compared to VDP in responders to bronchodilation based on VDP (VDP responders) and forced expiratory volume in 1 s (FEV1) (FEV1 responders).ResultsIn total, 47 patients with asthma (18 males 39 ± 13 years, FEV1 = 79 ± 21%) reported significantly improved FEV1, FEV1/forced vital capacity (FVC), residual volume (RV)/total lung capacity (TLC) (all P = .0001) and VDP (P = .01) post-salbutamol. Post-salbutamol, VDP responders and nonresponders to salbutamol were significantly different for coarse-texture features including long-run emphasis (LRE) and long-run, low gray-level emphasis (LRLGE, both P < .05) and for FEV1 responders to salbutamol, there was significantly different long-run, high gray-level emphasis (LRHGE, P = .04). There were significant relationships for VDP with LRE (R = .50, P = .0003), LRLGE (R = .34, P = .02), and LRHGE (R = .56, P = .0001). Receiver operating characteristic curves showed VDP with the strongest performance (AUC = .92), followed by coarse-texture classifier LRHGE (AUC = .83), FEV1 (AUC = .80), LRE (AUC = .66), FVC (AUC = .58), and LRLGE (AUC = .42).ConclusionsIn patients with asthma, differences in ventilation patchiness post-salbutamol can be quantified using coarse-texture classifiers that are significantly different in bronchodilator responders.Copyright © 2015 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

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