Efficacy and Safety of Gefapixant for Refractory or Unexplained Chronic Cough over 52 Weeks

have increased sensitivity for classifying voxels close to the 2856 HU threshold (3).However, further investigations into the pathophysiological mechanisms associated with the PRM and DPM classification differences are needed.This study emphasizes that the measurement of fSAD by CT is critically dependent on breathing instructions.A precise assessment of fSAD is crucial for determining early disease etiology (7) and the efficacy of treatments in patients with early stages of COPD as well as in symptomatic smokers without spirometric evidence of obstructive lung disease (8).Therapies that target fSAD have the potential not only to reduce air trapping but also to slow and even reverse the development of COPD.It is recognized that the measurement of fSAD by CT is critically dependent on breathing instructions.Coaching to RV in a clinical setting will require careful training of CT technologists to deliver instructions similar to those delivered in a pulmonary function laboratory.