Fibrosing interstitial lung disease (F-ILD) are a heterogeneous group of diseases with multiple subtypes. Both idiopathic pulmonary fibrosis and other ILDs associated with a risk of developing progressive pulmonary fibrosis (PPF) are subtypes of this category. A multidisciplinary team discussion, including a chest high-resolution CT (HRCT), is usually considered the gold standard for diagnosis of F-ILD. Repeated HRCT is one of several established methods to assess progression and thus development of PPF, but it is associated with substantial costs and radiation exposure. Thoracic ultrasound (TUS) and other ultrasound (US) methods have emerged as radiation-free methods for both diagnosing and monitoring disease severity in F-ILD. Yet, consistent knowledge on the use of different TUS- and US methods in patients with F-ILD is limited.

The LORD study is a prospective cohort study conducted in participants with F-ILD at a tertiary ILD centre in Denmark. Physiological testing and patient-related outcome measures, together with TUS- and US examinations, will be performed at inclusion, after 6 and 12 months. The correlations between these assessments will be evaluated. HRCT will be conducted between 3 months prior to and 1 month after baseline, and after 1 year. At least 34 participants will be included.

The protocol was approved by the Danish Data Protection Agency (journal number: 22/45135) and the Science Ethics Committee for the Region of Southern Denmark (journal number: S-20220036). Results will be published in peer-reviewed international journals and will be presented at an international congress.

NCT06844331.