Pathologically proved nonspecific interstitial pneumonia: CT pattern analysis as compared with usual interstitial...

Area of Science:

• Pulmonary Medicine
• Radiology
• Pathology

Background:

• Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with variable clinical outcomes.
• Nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP) are distinct histopathologic patterns affecting lung function.
• Accurate differentiation of UIP and NSIP patterns is crucial for predicting patient prognosis.

Purpose of the Study:

• To evaluate the consistency of computed tomography (CT) imaging patterns in patients diagnosed with pathologic NSIP.
• To correlate CT-identified patterns with the latest IPF classification guidelines.
• To assess the relationship between CT patterns, pathologic diagnosis, and predicted mortality.

Main Methods:

• Retrospective analysis of 114 patients with pathologically confirmed NSIP (n=39) or UIP with clinical IPF (n=75).
• Two independent observer groups assessed CT scans for specific patterns: UIP, possible UIP, indeterminate, NSIP, and alternative diagnosis.
• CT findings were compared with pathologic diagnoses and patient outcomes using log-rank tests and Kaplan-Meier curves.

Main Results:

• CT scans classified 17 cases as UIP, 24 as possible UIP, 13 as indeterminate, and 56 as NSIP.
• A CT diagnosis of NSIP was achieved in 35 of 39 patients with pathologic NSIP.
• Mean survival times varied significantly: UIP (33.5 months), possible UIP (73.0 months), indeterminate (101.0 months), and NSIP (140.2 months).
• Patients with CT-diagnosed UIP had significantly worse outcomes than those with possible UIP, indeterminate, or NSIP patterns (P < .018).

Conclusions:

• CT imaging patterns in patients with pathologically confirmed NSIP exhibit greater uniformity compared to those with pathologically confirmed UIP.
• The CT pattern suggestive of NSIP is associated with a more favorable patient prognosis than the CT pattern indicative of UIP.