Parametric response mapping monitors temporal changes on lung CT scans in the subpopulations and intermediate outcome measures in COPD Study (SPIROMICS).

TitleParametric response mapping monitors temporal changes on lung CT scans in the subpopulations and intermediate outcome measures in COPD Study (SPIROMICS).
Publication TypePublication
AuthorsBoes JL, Hoff BA, Bule M, Johnson TD, Rehemtulla A, Chamberlain R, Hoffman EA, Kazerooni EA, Martinez FJ, Han MK, Ross BD, Galbán CJ
JournalAcad Radiol
Date Published2015 Feb
KeywordsAdult, Aged, Aged, 80 and over, Algorithms, Disease Progression, Female, Humans, Longitudinal Studies, Lung, Male, Middle Aged, Pattern Recognition, Automated, Pulmonary Disease, Chronic Obstructive, Radiographic Image Enhancement, Radiographic Image Interpretation, Computer-Assisted, Reproducibility of Results, Sensitivity and Specificity, Subtraction Technique, Tomography, X-Ray Computed

RATIONALE AND OBJECTIVES: The longitudinal relationship between regional air trapping and emphysema remains unexplored. We have sought to demonstrate the utility of parametric response mapping (PRM), a computed tomography (CT)-based biomarker, for monitoring regional disease progression in chronic obstructive pulmonary disease (COPD) patients, linking expiratory- and inspiratory-based CT metrics over time.MATERIALS AND METHODS: Inspiratory and expiratory lung CT scans were acquired from 89 COPD subjects with varying Global Initiative for Chronic Obstructive Lung Disease (GOLD) status at 30 days (n = 13) or 1 year (n = 76) from baseline as part of the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) clinical trial. PRMs of CT data were used to quantify the relative volumes of normal parenchyma (PRM(Normal)), emphysema (PRM(Emph)), and functional small airways disease (PRM(fSAD)). PRM measurement variability was assessed using the 30-day interval data. Changes in PRM metrics over a 1-year period were correlated to pulmonary function (forced expiratory volume at 1 second [FEV1]). A theoretical model that simulates PRM changes from COPD was compared to experimental findings.RESULTS: PRM metrics varied by ∼6.5% of total lung volume for PRM(Normal) and PRM(fSAD) and 1% for PRM(Emph) when testing 30-day repeatability. Over a 1-year interval, only PRM(Emph) in severe COPD subjects produced significant change (19%-21%). However, 11 of 76 subjects showed changes in PRM(fSAD) greater than variations observed from analysis of 30-day data. Mathematical model simulations agreed with experimental PRM results, suggesting fSAD is a transitional phase from normal parenchyma to emphysema.CONCLUSIONS: PRM of lung CT scans in COPD patients provides an opportunity to more precisely characterize underlying disease phenotypes, with the potential to monitor disease status and therapy response.

Alternate JournalAcad Radiol
PubMed ID25442794
PubMed Central IDPMC4289437
Grant ListUL1 TR000433 / TR / NCATS NIH HHS / United States
HHSN268200900017C / / PHS HHS / United States
T32EB005172 / EB / NIBIB NIH HHS / United States
S10 OD018526 / OD / NIH HHS / United States
HHSN268200900015C / / PHS HHS / United States
HHSN268200900020C / / PHS HHS / United States
P30 ES005605 / ES / NIEHS NIH HHS / United States
HHSN268200900018C / / PHS HHS / United States
P50CA93990 / CA / NCI NIH HHS / United States
R01HL122438 / HL / NHLBI NIH HHS / United States
HHSN268200900014C / / PHS HHS / United States
R01 HL122438 / HL / NHLBI NIH HHS / United States
R44 HL118837 / HL / NHLBI NIH HHS / United States
P01CA085878 / CA / NCI NIH HHS / United States
P30 DK054759 / DK / NIDDK NIH HHS / United States
HHSN2682009000019C / / PHS HHS / United States
HHSN268200900013C / / PHS HHS / United States
R44HL118837 / HL / NHLBI NIH HHS / United States
P01 CA085878 / CA / NCI NIH HHS / United States
HHSN268200900016C / / PHS HHS / United States
T32 EB005172 / EB / NIBIB NIH HHS / United States
P50 CA093990 / CA / NCI NIH HHS / United States
Manuscript Lead/Corresponding Author Affiliation: 
Clinical Center: Michigan (University of Michigan)
Manuscript Status: