High-Resolution Computed Tomography in Idiopathic Pulmonary Fibrosis

TLDR

High‑resolution computed tomography (HRCT) is a key diagnostic tool for idiopathic pulmonary fibrosis, yet few large‑cohort studies have examined its clinical utility. This study aimed to characterize HRCT features in mild‑to‑moderate IPF, compare core versus site radiologist diagnoses, correlate HRCT findings with baseline clinical and physiologic variables, and assess their relationship with mortality. We evaluated HRCT scans from 315 IPF patients enrolled in a randomized controlled trial of IFN‑γ1b, with diagnoses reviewed by a core panel of three thoracic radiologists and compared to study‑site interpretations. HRCT findings showed 86 % concordance between core and site radiologists; diffusing capacity of carbon monoxide was the strongest physiologic correlate, and multivariate analysis revealed that greater fibrosis extent increased mortality risk while higher DLCO and IFN‑γ1b treatment lowered it, confirming that reticulation and honeycombing are independent predictors of death.

Abstract

High-resolution computed tomography (HRCT) is an integral aspect of the evaluation of patients with suspected idiopathic pulmonary fibrosis (IPF). However, few studies have evaluated its use in a large cohort.To describe HRCT features in patients with mild to moderate IPF, compare diagnostic evaluations by a radiology core (three thoracic radiologists) with those by study-site radiologists, correlate baseline clinical and physiologic variables with HRCT findings, and evaluate their association with mortality.We assessed HRCT scans from patients with IPF (n = 315) enrolled in a randomized controlled study evaluating IFN-gamma1b.There was concordance between study-site and core radiologists regarding the diagnosis of IPF in 86% of cases. Diffusing capacity of carbon monoxide (DLCO) was the physiologic characteristic most highly correlated with HRCT findings. Multivariate analysis identified three independent predictors of mortality: a higher extent of fibrosis score increased the risk of death (p < 0.0001), whereas a higher percent-predicted DLCO (p = 0.004) and treatment assignment to IFN-gamma1b rather than placebo (p = 0.04) reduced the risk of death.A study-site diagnosis of IPF on HRCT was regularly confirmed by core radiologists. Extent of reticulation and honeycombing on HRCT is an important independent predictor of mortality in patients with IPF.