Pathologic subgroups of nonspecific interstitial pneumonia: differential diagnosis from other idiopathic interstitial pneumonias on high-resolution computed tomography.
OBJECTIVE
To determine whether the subtypes of nonspecific interstitial pneumonia (NSIP) could be differentiated from other idiopathic interstitial pneumonias (IIPs) on the basis of findings on high-resolution computed tomography (CT).


METHODS
Two observers evaluated the high-resolution CT findings in 90 patients with IIPs. The patients included 36 with NSIP, 11 with usual interstitial pneumonia (UIP), 8 with cryptogenic organizing pneumonia (COP), 10 with acute interstitial pneumonia (AIP), 14 with desquamative interstitial pneumonia (DIP) or respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and 11 with lymphoid interstitial pneumonia (LIP). The NSIP cases were subdivided into group 1 NSIP (n = 6), group 2 NSIP (n = 15), and group 3 NSIP (n = 15).


RESULTS
Observers made a correct diagnosis with a high level of confidence in 65% of NSIP cases, 91% of UIP cases, 44% of COP cases, 40% of AIP cases, 32% of DIP or RB-ILD cases, and 82% of LIP cases. Group 1 NSIP was misdiagnosed as AIP, DIP or RB-ILD, and LIP in 8.3% of patients, respectively. Group 2 NSIP was misdiagnosed as COP in 10% of patients, LIP in 6.7%, AIP in 3.3%, and DIP or RB-ILD in 3.3%. Group 3 NSIP was misdiagnosed as UIP in 6.7% of patients, COP in 6.7%, and DIP or RB-ILD in 3.3%.


CONCLUSIONS
In most patients, NSIP can be distinguished from other IIPs based on the findings on high-resolution CT. Only a small percentage of patients with predominantly fibrotic NSIP (group 3 NSIP) show overlap with the high-resolution CT findings of UIP.
Tsubamoto
Mitsuko
M
Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan. tubamoto@radiol.med.osaka-u.ac.jp
Müller
Nestor L
NL
Johkoh
Takeshi
T
Ichikado
Kazuya
K
Taniguchi
Hiroyuki
H
Kondoh
Yasuhiro
Y
Fujimoto
Kiminori
K
Arakawa
Hiroaki
H
Koyama
Mitsuhiro
M
Kozuka
Takenori
T
Inoue
Atsuo
A
Sumikawa
Mitsuhiro
M
Murai
Sachiko
S
Honda
Osamu
O
Tomiyama
Noriyuki
N
Hamada
Seiki
S
Nakamura
Hironobu
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D017563:Lung Diseases, Interstitial / Q000145:classification* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D014057:Tomography, X-Ray Computed / Q000379:methods*