Comparison of capability of dynamic O ₂-enhanced MRI and quantitative thin-section MDCT to assess COPD in smokers

Purpose: The purpose of this study was to directly and prospectively compare the capability of dynamic O ₂-enhanced MRI and quantitatively assessed thin-section MDCT to assess smokers' COPD in a large prospective cohort. Materials and methods: The GOLD criteria for smokers were used to classify 187 smokers into four clinical stage groups as follows: smokers without COPD (n = 56) and with mild (n = 54), moderate (n = 52) and severe or very severe COPD (n = 24). All smokers underwent dynamic O ₂-enhanced MRI, MDCT and pulmonary function tests. Mean relative enhancement ratio and mean wash-in time on MRI and CT-based functional lung volume (CT-based FLV) as well as the ratio of airway wall area to total airway area on MDCT were computationally calculated. Then, all indexes were significantly correlated with functional parameters. To determine the efficacy of all indexes for clinical stage classification, the indexes for the four clinical groups were statistically compared by using Tukey's honestly significant difference multiple comparison test. Results: All indexes had significant correlations with functional parameters (p < 0.0001). All indexes except CT-based FLV in all groups had significant differences each other (p < 0.05). Conclusions: Dynamic O ₂-enhanced MRI for assessment of COPD in smokers is potentially as efficacious as quantitatively assessed thin-section MDCT.