Quantitative computed tomography measurements to evaluate airway disease in chronic obstructive pulmonary disease: relationship to physiological measurements, clinical index and visual assessment of airway disease

• Published in: European journal of radiology 2016-11, Vol.85 (11), p.2144-2151
• Main Authors: Nambu, Atsushi, MD, PhD, Zach, Jordan, BA, Schroeder, Joyce, MD, Jin, Gongyoung, MD, PhD, Kim, Song Soo, MD, PhD, Kim, Yu-IL, MD, Schnell, Christina, BA, Bowler, Russell, MD, PhD, Lynch, David A., MB
• Format: Article
• Language: English
• Subjects: Aged; Air trapping; Airway disease; Body Mass Index; Chronic obstructive lung disease (COPD); Dyspnea - diagnostic imaging; Dyspnea - physiopathology; Female; Forced Expiratory Volume; Humans; Lung - diagnostic imaging; Lung - pathology; Male; Middle Aged; Pulmonary Disease, Chronic Obstructive - diagnostic imaging; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary Emphysema - diagnostic imaging; Pulmonary Emphysema - physiopathology; Quantitative CT; Radiographic Image Interpretation, Computer-Assisted; Radiology; Retrospective Studies; Severity of Illness Index; Smoking; Tomography, X-Ray Computed - methods
• ISSN: 0720-048X; 1872-7727
• DOI: 10.1016/j.ejrad.2016.09.010

Abstract Purpose To correlate currently available quantitative CT measurements for airway disease with physiological indices and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods This study was approved by our institutional review board (IRB number 2778). Written informed consent was obtained from all subjects. The subjects included 188 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had physiological measurements for the evaluation of airflow limitation, including FEF25-75%, airway resistance (Raw), and specific airway conductance (sGaw). The BODE index was used as the index of clinical symptoms. Quantitative CT measures included % low attenuation areas (%LAA, voxels ≤ 950 Hounsfield unit (HU), %LAA-950ins ), percent gas trapping (% voxels < −856 HU at expiratory CT, %LAA-856exp ), relative inspiratory to expiratory volume change of voxels with attenuation values from −856 to −950 HU [Relative Volume Change (RVC)-856to-950 %], expiratory to inspiratory ratio of mean lung density (E/I-ratioMLD ), Pi10, airway wall thickness (WT), luminal diameter (LD) and airway wall area percent (WA %) in the segmental, subsegmental and subsubsegmental bronchi on inspiratory CT. Correlation coefficients were calculated between the QCT measurements, visual assessment and physiological measurements in all subjects and in the subjects with mild emphysema (% LAA-950ins