Martinez CH, Diaz AA, Meldrum C, Curtis JL, Cooper CB, Pirozzi C, Kanner RE, Paine R, Woodruff PG, Bleecker ER, Hansel NN, Barr RG, Marchetti N, Criner GJ, Kazerooni EA, Hoffman EA, Ross BD, Galban CJ, Cigolle CT, Martinez FJ, Han MK. Age and Small Airway Imaging Abnormalities in Subjects with and without Airflow Obstruction in SPIROMICS. Am J Respir Crit Care Med. 2017 Feb 15; 195(4):464-472.