Advanced Imaging to Assess the Effect of Immunosuppression on Progressive Fibrosis

15 different subjects with non-IPF ILD starting immunosuppression treatment for their underlying ILD will be enrolled. Participants will undergo [68Ga]CBP8 PET and DCE-MRI prior to and 12 weeks after treatment initiation to determine the effects of immunosuppressive treatment on PET measurements of collagen deposition and selected DCE-MRI-derived measurements.

Inclusion criteria

• Age 18-80 with a diagnosis of chronic hypersensitivity pneumonitis, connective tissue-associated ILD (due to rheumatoid arthritis, systemic sclerosis, mixed connective tissue disease), or undifferentiated ILD.
• Starting immunosuppression treatment with mycophenolate mofetil, mycophenolate sodium, and / or prednisone for clinically indicated non-IPF ILD treatment.
• Pulmonary fibrosis, defined as honeycombing, traction bronchiectasis, or reticular opacities on high-resolution computed tomography (HRCT) performed within 1 year to or at Visit 1.
• Forced vital capacity (FVC) of >/= 45% and diffusing capacity of the lungs for carbon monoxide (DLCO) >/= 25% predicted on PFTs performed at Visit 1.

Exclusion criteria

• Current or prior exposure to FDA approved anti-fibrotic therapy.
• Extent of emphysema greater than extent of fibrosis.
• Pregnancy or plans to become pregnant at baseline or during follow-up.
• Contraindications to MRI.
• Contraindications to receiving gadolinium-based contrast agents.
• Research-related radiation exposure exceeds 50 millisievert (mSv) in the prior year.
• Estimated glomerular filtration rate (eGFR) < 30 mL/min (only for individuals with a history of chronic kidney disease).
• Clinically significant pulmonary hypertension (PH) defined by use of pulmonary vasodilatory therapy.
• Respiratory infection within the prior 6 weeks.
• Smoking of any kind within the prior 6 months.