Mass General - Division of Clinical Research

Group 1: First degree relatives of a family member with pulmonary fibrosis (n=8) - Age greater than 40 years - Have the ability to give written informed consent - First degree relative of a family member with pulmonary fibrosis - No known history of interstitial lung disease - No tobacco use within the prior 6 months. Group 2: Subjects with interstitial lung abnormalities (ILAs) or interstitial lung disease (ILD) (n=22) - Age greater than 40 years - Have the ability to give written informed consent - ILAs or early ILD (defined by presence of reticular markings and / or traction bronchiectasis but absence of a definite UIP pattern) - No tobacco use within the prior 6 months.

• Electrical implants such as cardiac pacemaker or perfusion pump - Ferromagnetic implants such as aneurysm clips, surgical clips, prostheses, artificial hearts, valves with steel parts, metal fragments, shrapnel, metallic tattoos anywhere on the body, tattoos near the eye, or steel implants ferromagnetic objects such as jewelry or metal clips in clothing - Historical eGFR of less than 30 mL/min/1.73 m2 - Pregnant or breastfeeding (a negative quantitative serum hCG pregnancy test is required for females having child-bearing potential before the subject can participate) - Claustrophobic reactions - Research-related radiation exposure exceeds current Radiology Department guidelines (i.e. 50 mSv in the prior 12 months) - Unable to lie comfortably on a bed inside the MR-PET - BMI > 33 (limit of the PET-MRI table) - Determined by the investigator(s) to be clinically unsuitable for the study (e.g. based on screening visit and/or during study procedures) - Pneumonia or other acute respiratory illness within 6 weeks of study entry - Parenchymal lung disease except for ILD/ILAs or emphysema - Acute exacerbation of ILD within the prior 6 months - VATS within the prior 6 months - Prior radiation therapy to the thorax - Known allergy to gadolinium.