Parametric response mapping on chest computed tomography associates with clinical and functional parameters in chronic obstructive pulmonary disease. (February 2017)

• Record Type: Journal Article
• 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.
• Is Part Of: Respiratory medicine. Volume 123(2017)
• Page Start: 48
• Page End: 55
• Publication Date: 2017-02
• Subjects: Computed tomography -- Parametric response mapping -- Copd -- Phenotypes -- Emphysema -- Small airway disease; 6MWD six minute walking distance -- BMI body mass index -- COPD chronic obstructive pulmonary disease -- CT computed tomography -- E/I-ratioMLD expiration to inspiration ratio of mean lung density -- FEV1 forced expiratory volume in one second -- FVC forced vital capacity -- KCO gas transfer corrected for lung volume -- MRC Medical Research Council -- Perc15 emphysema score as 15th percentile of attenuation distribution curve on inspiratory scan -- PRM parametric response mapping -- RV residual volume -- SGRQ St George's Respiratory Questionnaire -- TLC total lung capacity -- TLCO diffusion capacity of the lung for carbon monoxide -- VA alveolar volume -- VC vital capacity; Chest -- Diseases -- Periodicals; Chest -- Diseases -- Great Britain -- Periodicals; Respiratory organs -- Diseases -- Periodicals; Respiratory Tract Diseases -- Periodicals; Appareil respiratoire -- Maladies -- Périodiques; Thorax -- Maladies -- Périodiques; Appareil respiratoire -- Maladies -- Traitement -- Périodiques; Electronic journals; 616.2
• DOI: 10.1016/j.rmed.2016.11.021
• Languages: English
• ISSNs: 0954-6111

Abstract

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 (PRM Emph ) and non-emphysematous air trapping (i.e. functional small airway disease, PRM fSAD ). 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 PRM Emph and PRM fSAD were more strongly correlated with lung function parameters as compared to Perc15 and E/I-ratioMLD . PRM Emph and PRM fSAD 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 PRM fSAD 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 PRM Emph 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. Highlights: PRM biomarkers of small airway disease and emphysema increase with GOLD stage. Both PRM biomarkers are associated with clinically important parameters for COPD. PRM provides important information on disease phenotype and severity.