[Analysis of fibrotic lung diseases by long-term evaluation with 133Xe functional imaging]

Semiquantitative analysis of regional lung function was carried out using 133Xe functional imaging, which can be performed repeatedly in a non-invasive and effortless way, on 33 patients with fibrotic lung disease, which often occurs in aged patients with decreased lung function. The results of this analysis were compared with those obtained by conventional methods, including chest X-ray and CT examinations and testing of whole lung function. The results obtained from the 33 patients (fibrotic group) were also compared with those obtained from 28 normal adults (control group), and 7 of the 33 patients were followed up for a long period of time. In the fibrotic group, both V/V and Q/V decreased in bilateral lower lung zones, while Q/V increased in upper lung zones, resulting in a tendency toward less differences in V/Q among upper, middle and lower zones. The mean MWT in the whole lung was shortened to 68 +/- 13 sec. in the fibrotic group from 74 +/- 9 sec. observed in the control group. Such a difference in MWT between the fibrotic and control groups was also seen in the upper and middle zones. As for long-term changes, although V/V showed no marked changes, Q/V demonstrated progressive and remarkable decreases in the lower lung zone, therefore, V/Q was uniformly distributed over the whole lung in appearance. MWT was prolonged with time in all of the 7 patients.(ABSTRACT TRUNCATED AT 250 WORDS)