Pneumothorax and idiopathic pulmonary fibrosis.
OBJECTIVE
We evaluated the relation between the severity of idiopathic pulmonary fibrosis (IPF) and the incidence of pneumothorax on computed tomography (CT) images.


METHODS
In this retrospective study, we evaluated the presence of pneumothorax in 56 consecutive patients who died of IPF from the initial CT to death. We quantitatively analyzed a total of 207 CT images and measured the volume of the normal pattern (N-pattern) and each lesion pattern on the initial CT and their serial changes. The effects of pneumothorax and clinical and CT features on survival were evaluated using Cox regression analysis.


RESULTS
Pneumothorax occurred in 17 of 56 patients. Comparison of the pneumothorax (+) and (-) groups showed the initial vital capacity (VC) was lower (P = 0.005) and the follow-up period was shorter (P = 0.03) in the former group. The decrease in the N-pattern volume in the pneumothorax(+) group was significantly faster than in the pneumothorax(-) group (P = 0.013). Cox regression analyses identified a rapid decrease in N-pattern volume (P = 0.008) and a rapid decrease in VC (P = 0.002), but not pneumothorax, as significant predictors of poor survival.


CONCLUSIONS
Pneumothorax in IPF patients is associated with lower VC and rapid deterioration of CT findings. The findings suggest that pneumothorax is a complication of advanced IPF.
Department of Radiology, Kanagawa Cardiovascular and Respiratory Center, Kanazawa-ku, Yokohama, Japan. tae_i_md@wb3.so-net.ne.jp
Tae
T
Iwasawa
Takashi
T
Ogura
Hiroshi
H
Takahashi
Akira
A
Asakura
Toshiyuki
T
Gotoh
Takuya
T
Yazawa
Tomio
T
Inoue
D000368:Aged; D000704:Analysis of Variance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000150:complications / Q000000981:diagnostic imaging*; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D011030:Pneumothorax / Q000150:complications / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014797:Vital Capacity