Parametric response mapping on chest computed tomography associates with clinical and functional parameters in chronic obstructive pulmonary disease

• Published in: Respiratory medicine Vol. 123; pp. 48 - 55
• Main Authors: Pompe, Esther, Galbán, Craig J, Ross, Brian D, Koenderman, Leo, ten Hacken, Nick HT, Postma, Dirkje S, van den Berge, Maarten, de Jong, Pim A, Lammers, Jan-Willem J, Mohamed Hoesein, Firdaus AA
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2017; Elsevier Limited
• Subjects: Adolescent; Adult; Age; Aged; Biomarkers; Body mass index; Chronic obstructive pulmonary disease; Computed tomography; Copd; Disease; Dyspnea; Emphysema; Female; Forced Expiratory Volume - physiology; Humans; Image Interpretation, Computer-Assisted - methods; Male; Medical imaging; Medical research; Middle Aged; Multivariate analysis; Parametric response mapping; Phenotype; Phenotypes; Pulmonary Disease, Chronic Obstructive - diagnostic imaging; Pulmonary Disease, Chronic Obstructive - etiology; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary Emphysema - diagnostic imaging; Pulmonary Emphysema - physiopathology; Pulmonary/Respiratory; Questionnaires; Respiratory Function Tests; Retrospective Studies; Severity of Illness Index; Small airway disease; Smoking - adverse effects; Tomography; Tomography, X-Ray Computed - methods; Vital Capacity - physiology; Young Adult; TLCO; RV; forced vital capacity; PRM; TLC; vital capacity; Computed tomography; Small airway disease; gas transfer corrected for lung volume; BMI; Copd; emphysema score as 15th percentile of attenuation distribution curve on inspiratory scan; residual volume; Phenotypes; Perc15; St George's Respiratory Questionnaire; expiration to inspiration ratio of mean lung density; body mass index; E/I-ratio MLD; alveolar volume; VA; VC; forced expiratory volume in one second; CT; FVC; FEV 1; total lung capacity; SGRQ; diffusion capacity of the lung for carbon monoxide; KCO; six minute walking distance; Medical Research Council; Parametric response mapping; Emphysema; 6MWD; chronic obstructive pulmonary disease; MRC; E/I-ratioMLD; FEV1
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2016.11.021

Abstract Background In the search for specific phenotypes of chronic obstructive pulmonary disease (COPD) computed tomography (CT) derived Parametric Response Mapping (PRM) has been introduced. This study evaluates the association between PRM and currently available biomarkers of disease severity in COPD. Methods Smokers with and without COPD were characterized based on questionnaires, pulmonary function tests, body plethysmography, and low-dose chest CT scanning. PRM was used to calculate the amount of emphysema (PRMEmph ) and non-emphysematous air trapping (i.e. functional small airway disease, PRMfSAD ). PRM was first compared with other biomarkers for emphysema (Perc15) and air trapping (E/I-ratioMLD ). Consequently, linear regression models were utilized to study associations of PRM measurements with clinical parameters. Results 166 participants were included with a mean±SD age of 50.5±17.7 years. Both PRMEmph and PRMfSAD were more strongly correlated with lung function parameters as compared to Perc15 and E/I-ratioMLD . PRMEmph and PRMfSAD were higher in COPD participants than non-COPD participants (14.0% vs. 1.1%, and 31.6% vs. 8.2%, respectively, both p<0.001) and increased with increasing GOLD stage (all p<0.001). Multivariate analysis showed that PRMfSAD was mainly associated with total lung capacity (TLC) (β=-7.90, p<0.001), alveolar volume (VA) (β=7.79, p<0.001), and residual volume (β=6.78, p<0.001), whilst PRMEmph was primarily associated with Kco (β=8.95, p < 0.001), VA (β=-6.21, p<0.001), and TLC (β=6.20, p < 0.001). Conclusions PRM strongly associates with the presence and severity of COPD. PRM therefore appears to be a valuable tool in differentiating COPD phenotypes.