Evaluation of the Value of 18F-Fluoromisonidazole (18F-FMISO) Positron Emission Tomography Hypoxia Imaging in Idiopathic Pulmonary Fibrosis

Inclusion Criteria: For all patients (IPF and healthy volunteers) : * Person who has given written consent * Age ≥ 50 years * Absence of disease, comorbidity, or treatment that may interfere with the evaluation of the study objective, as decided by the investigator For patients with IPF only: * Diagnosis of IPF according to the criteria of the current international recommendations (ATS/ERS/JRS/ALAT of 2011) and validated in a multi-disciplinary meeting in a Competence or Reference Center * Patients who have had a high-resolution thoracic CT scan less than 1 month previously as part of the management of their disease * Patients who have had a PFT less than 1 month previously as part of the management of their disease For healthy volunteers only: * Absence of functional respiratory signs - absence of dyspnea on exertion and at rest and absence of chronic cough. * Normal clinical examination with no crackles on pulmonary auscultation * No personal history of chronic hypoxemic respiratory disease Exclusion Criteria: * Person who is not covered by national health insurance * Cancer or history of cancer in the past 5 years (except basal cell skin cancer) * Chronic lung disease other than IPF or a history incompatible with the diagnosis of idiopathic pulmonary fibrosis (thoracic radiotherapy, pneumotoxic chemotherapy, etc.) * Exacerbation of IPF during treatment * Active smoking * Patient requiring long-term oxygen therapy (excluding ambulatory oxygen therapy alone) * Contraindication to PET or CT scan or presence of a condition disturbing the interpretation : * known allergy to 18F-FMISO * pregnancy or breastfeeding * claustrophobia * uncontrolled type I/II diabetes (HbA1c \>7%) * surgical intervention in the previous month * Radiotherapy session in the previous 3 months * concomitant granulomatous condition (sarcoidosis type) or pulmonary inflammation * Moderate or severe renal insufficiency (GFR \< 70 ml/min/1.73 m²) * Person under legal protection (curatorship, guardianship) * Adult unable to express consent * SECONDARY EXCLUSION CRITERIA only for healthy volunteers * Abnormal 6 min walk test at screening * Abnormal PFT at screening with FVC ≤ 80% of predicted value and DLCO ≤ 75% of predicted value