[Evaluation of lung lobar ventilation dynamics with magnetic resonance imaging: a comparison of interstitial pneumonia patients with normal subjects]

Magnetic resonance imaging (MRI) was utilized to study lung lobar dynamic ventilation in 11 patients with interstitial pneumonia (IP) and 10 non-smoking men. The IP patients included 7 with interstitial lung disease associated with collagen vascular disease, 3 with idiopathic interstitial pneumonia, and 1 with lung cancer who was excluded from statistical analysis. We calculated lung lobar volumes in each phase from each dynamic image and constructed time-volume curves(TVCs). Lung lobar volume rates(%), fluctuation rates(%), lobar fluctuation rate/total lung fluctuation rate (%), and time lag (sec.) for the IP patients and normal subjects were calculated and compared. In the former, the mean volume rate for the right upper lobe was larger (p0.01) than that in normal subjects. The mean volume rate for the left lower lobe in the IP patients was smaller(p0.01) than that in the normal subjects. In IP patients, peak TVC for the right middle lobe appeared later (p0.01) than that in normal subjects. Although the fluctuation rates and fluctuation rate/total lung fluctuation rate for the lower lobes tended to be higher than those for the upper and middle lobes in normal subjects, this tendency was not distinct in IP patients. The quantitative evaluation of pulmonary ventilation dynamics with MRI may be a useful noninvasive technique for the assessment of lung lobar ventilation in patients with IP.