Chronic hypersensitivity pneumonitis and pulmonary sarcoidosis: differentiation from usual interstitial pneumonia using high-resolution computed tomography.
The distinction of chronic hypersensitivity pneumonitis (HP) or advanced-stage sarcoidosis from idiopathic pulmonary fibrosis or usual interstitial pneumonia is important because each disease is managed differently and may have a different prognosis. The analyses of pattern and distribution of lung parenchymal abnormalities on high-resolution computed tomography scans help differentiate among the 3 diseases. In chronic HP, the presence of lobular areas of decreased attenuation and centrilobular small nodules and the absence of lower lung zone predominance are characteristically observed. In advanced-stage sarcoidosis, patchy areas of reticulation, traction bronchiectasis, architectural distortion, honeycomblike cysts, bullae, and paracicatricial emphysema are observed in the upper and middle lung zones. Lung bases are usually spared. In idiopathic pulmonary fibrosis or usual interstitial pneumonia, however, the presence of honeycombing with lower lung zone predominance and the absence of centrilobular small nodules are important findings that allow us to differentiate the disease from chronic HP or advanced-stage sarcoidosis. In the 3 diseases, most important prognosis-predicting factor is the extent of fibrotic score (the extent of honeycombing and reticulation) calculated on high-resolution computed tomography scans or fibrosis estimated on chest radiographs.
Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Pusan, Republic of Korea.
Yeon Joo
YJ
Jeong
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: kyungs.lee@samsung.com.
Kyung Soo
KS
Lee
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Man Pyo
MP
Chung
Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Joungho
J
Han
Department of Radiology, Kinki Central Hospital Mutual Add Association of Public School Teachers, Itami, Japan.
Takeshi
T
Johkoh
Division of Respiratory Medicine, Saiseikai Kumamoto Hospital, Kumamoto, Japan.
Kazuya
K
Ichikado
D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000000981:diagnostic imaging* / Q000473:pathology; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000000981:diagnostic imaging; D008168:Lung / Q000000981:diagnostic imaging; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D017565:Sarcoidosis, Pulmonary / Q000000981:diagnostic imaging* / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*