To evaluate the findings on thin-section computed tomographic (CT) sca
ns in desquamative interstitial pneumonia (DIP), the CT scans from 22
patients aged 22-71 years (mean age, 43 years) were reviewed. In all p
atients, DIP was proved with open-lung biopsy performed 1 day to 17 mo
nths before or after examination with CT (median interval, 1.5 months)
. The lungs were divided into three zones (upper, middle, and lower);
each zone was evaluated separately. The predominant finding was the pr
esence of areas of ground-glass attenuation that involved the middle a
nd lower lung zones in all patients and the upper lung zones in 18 pat
ients (82%). Such areas had a lower lung zone predominance in 16 patie
nts (73%) and a predominantly peripheral distribution in 13 patients (
59%). Irregular lines of attenuation suggestive of fibrosis were seen
in 11 patients (50%) and cystic changes, in seven patients (32%). The
distribution of abnormalities in DIP is similar to that seen in usual
interstitial pneumonia (UIP), but the greater extent of ground-glass a
ttenuation and the paucity of cystic changes in DIP should enable dist
inction from UIP in most patients.