대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

NSIP (Nonspecific Interstitial Pneumonia / Fibrosis) associated with Rheumatoid Arthritis

Radiologic Findings

Chest radiograph shows irregular streaky density in peripheral fields of both lower lungs. Thin section CT scans obtained at lower lung level show areas of irregular consolidation, GGO and interlobular septal thickening. Thin section CT scan of corresponding lung obtained 6 months later show decrease in extent of parenchymal opacity with residual areas of GGO and septal thickening predominantly in peripheral lungs.

Brief Review

Nonspecific interstital pneumonia/fibrosis(NSIP) was first described in 1994 as a diagnosis of exclusion. The main pathologic findings is varying degrees of inflammation and fibrosis within alveolar walls that are temporally uniform in all sections. It may be patchy and, if so, often shows a peribronchiolar distribution.
In the original series 46% of patients had possible precipitating events or associated disorder, judged to be significant. These consisted of; (1) in 16% a variety of connective tissue disorders (rheumatoid arthritis, dermato/polymyositis, systemic lupus erythematosus, systemic sclerosis, Sjogren’s syndrom); (2) in 5% autoimmune disorders including primary biliary cirrhosis and Hashimoto thyroiditis; (3) in 8% recent surgery/ pneumonia/ ARDS; and (4) in 17% inhalation of possible noxious agents.
Abnormalities in chest radiography are usually bilateral with a basal predominance. They may be consolidation and patch, reticulonodular, or mixed. Other described features include reduced lung volume, pleural effusion (5%), hilar nodes(6%), and normality(6%). Detailed HRCT descriptions are available in 78 patients. A number of findings are described which may occur singly or in combination. The commonest abnormality (80% to 90%) is bilateral, patch ground-glass opacity either symmetrically or diffusely distributed in all zones or displaying a basal predominance. In 50% to 70% of patients it displays a subpleural predilection. Ground glass opacity occurs as an isolated finding in about one-third of patients. Consolidation is seen in 16%to 35% of patients, almost always combined with ground-glass opacity. Like ground-glass opacity, consolidation is bilateral, basal, and subpleurally predominant. Irregular linear opacities, commonly subpleural, occur in about 50% of cases (range 29% to 87%). Honeycomb changes recorded in 28% of patients in one series have been absent in others. Airway are commonly (38% to71%) dilated in areas of consolidation or ground-glass opacity, and Kim and colleagues described thickened bronchovascular bundles in 65% of cases.

References

1. Armstrong P, Wilson AG, et al. Image of Disease of the Chest, third edition. London: Mosby Publisher 2000:536-537
2. Park JS, Lee KS, Kim JS, et al. Nonspecific interstitial pneumonia with fibrosis: radiographic and CT findings in seven patients. Radiology 1995; 195:645-648
3. Kim TS, Lee KS, Chung MP, et al: Nonspecific interstitial pneumonia with fibrosis: high resolution CT and pathologic findings, AJR 171:1645-1650, 1998

Keywords

Lung, Connective tissue diseases, RA, NSIP, NSIP (Nonspecific Interstitial Pneumonia / Fibrosis) associated with Rheumatoid Arthritis