Pulmonary Imaging Phenotypes of Chronic Obstructive Pulmonary Disease Using Multiparametric Response Maps

Abstract

I n patients with chronic obstructive pulmonary disease (COPD), irreversible airflow obstruction related to parenchymal destruction, airway remodeling, and luminal obstruction (1) drives debilitating symptoms, poor quality of life, and premature death. While forced expiratory volume in 1 second (FEV 1) remains a key clinical and diagnostic measurement of COPD, it cannot provide regional information, nor can it be used to adequately discriminate between patients with different underlying diseases, such as airspace enlargement and small airways disease, that manifest differently in individual patients. To address some of the limitations of spirometry measurements, thoracic x-ray CT has yielded quantitative airway (2) and parenchyma (3) information, as well as indirect information related to small airways disease generated using parametric response maps (4-6). Pulmonary CT has been used widely in studies such as the Genetic Epidemiology of Chronic Obstructive Pulmonary Disease, or COPDGene (7), Subpopulations and Intermediate Outcome Measures in COPD, or SPIROMICS (8), Multi-Ethnic Study of Atherosclerosis, or MESA (9), Canadian Cohort Obstructive Lung Disease, or CANCold (10), and Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints, or ECLIPSE (11). CT parametric response maps are used to quantify COPD severity (4,12), monitor

Hyperpolarized 3helium MRI measured apparent diffusion coefficient and its correlations with pulmonary functions tests in patients with chronic obstructive pulmonary disease: A meta‐analysis

“…Some of the included studies also reported that ADC values were higher in patients with severe COPD in comparison with mild or moderate COPD. 24,[27][28][29]31 It is usually suggested that higher ADC values may indicate the presence of emphysematous areas. 7,9 A strong correlation is found between ADC values and emphysema index by 2 of the included studies.…”

Evaluation of small airway function and its application in patients with chronic obstructive pulmonary disease (Review)

“…Indeed, ADC was more sensitive than MLDE/I in distinguishing patients with COPD from healthy controls and was more strongly correlated with DLCO (34). Further study also suggested that multiparametric response maps based on CT and 3 He MRI are able to detect emphysema and small airway dysfunction in former smokers with normal pulmonary function and CT manifestations (35). However, 3 He is a rare isotope whose source is limited to a certain extent.…”

Computed tomography-identified phenotypes of small airway obstructions in chronic obstructive pulmonary disease

“…Given the relative contributions of fSAD and emphysema in COPD phenotypes, PRM serves as a complementary readout to PFTs and CT-based metrics, thereby aiding in the personalized diagnosis and management of COPD. [ 51 ]…”