THIN-SECTION CT OBTAINED AT 10-MM INCREMENTS VERSUS LIMITED 3-LEVEL THIN-SECTION CT FOR IDIOPATHIC PULMONARY FIBROSIS - CORRELATION WITH PATHOLOGICAL SCORING

OBJECTIVE. The purpose of our study was to determine if three-level th in-section CT depicts idiopathic pulmonary fibrosis (IPF) pathology as accurately as CT obtained at IO-mm increments throughout the entire l ungs. SUBJECTS AND METHODS. Thin-section (1.0- to 1.5-mm) images at 10 -mm increments were obtained and scored prospectively in 25 consecutiv e patients with newly diagnosed IPF who were participating in a Specia l Center of Research grant for interstitial lung disease, Each patient 's lobe was scored by four thoracic radiologists on a scale of 0-5 for both ground-glass attenuation and fibrosis. The radiologists used thr ee images (limited CT) and also used the entire data set (complete CT) . CT scores were compared with pathology scores from 67 open and thora coscopic biopsies. Limited and complete scores were compared with each other (Pearson correlation coefficient). Interobserver variation in t he CT scoring system was assessed using kappa values. RESULTS. CT fibr osis scores strongly correlated with pathology fibrosis scores for com plete (r = .53, p = .0001) and limited (r = .50, p = .0001) CT. CT gro und-glass scores correlated with the histologic inflammatory scores fo r each lobe on complete (r = .27, p = .03) and limited (r = .26, p = . 03) CT. The desquamative subcomponent of the pathology inflammatory sc ore had the highest correlation with the CT ground-glass scores (compl ete: r = .29, p = .01; limited: r = .33, p = .007). Good interobserver agreement existed for both the alveolar and fibrosis components of th e CT scoring system (kappa values ranging from .51 to .83) for each lo be of the lung on limited and complete CT. CONCLUSION. Limited thin-se ction CT reveals the pathologic changes associated with IPF as well as CT obtained at 10-mm increments. An added advantage of limited thin-s ection CT is that it exposes patients to less radiation.