Quantitative validation of the severity of emphysema by multi-detector CT

ObjectivesTo determine whether MDCT reflects the severity of chronic obstructive pulmonary disease (COPD) compared to the pulmonary function tests (PFTs).Patients and methodsA prospective study included 63 COPD patients. Spirometry was done and included forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and the ratio of forced expiratory volume in 1 s over forced vital capacity (FEV1/FVC). Patients were grouped according to GOLD guidelines. MDCT examinations were obtained during full inspiration. The extent of emphysema was quantified by using dedicated software. −950 Hounsfield units (HU) used as the percentage of low-attenuation (%LA) emphysematous areas. Statistical study between PFTs, and CT emphysema extent was performed.ResultsThe study included 26 females and 37 males with a mean age of 53 years. A moderate significant relationship was found between lung volume less than −950 HU and FVC, FEV1, and FEV1/FVC (p < 0.001). Pulmonary function tests revealed that 23.8% had mild restrictive defect, 14.3% had moderate obstructive defect and 61.9% had severe obstructive defect. A good correlation was observed between the quantitative assessments for the lower lung regions with −950 HU (%LA) and pulmonary function variables (p < 0.001).ConclusionMDCT results are significantly related to the data of PFTs for defining the severity of emphysema.