View article

To develop a semi‐automated segmentation method for generating novel helium‐3 (3He) magnetic resonance imaging (MRI) functional information from 3He and proton (1H) MRI, determine the relationship between measurements obtained by manual and semi‐automated segmentation, and apply this method in chronic obstructive pulmonary disease (COPD) patients to evaluate the lung functional effects of bronchodilator therapy. Fourteen COPD ex‐smokers provided written informed consent and underwent hyperpolarized 3He and 1H MRI, before and 25±2 minutes after administration of salbutamol. Semi‐ automated segmentation was accomplished in three steps: 1) hierarchical K‐ means clustering of 3He MR images into 5 clusters where cluster 1 (C1) represented regions of ventilation defect and background, and cluster 2 to cluster 5 (C2–C5) represented gradations of signal intensity …