Currently, there is no official recommendations for the respiratory surveillance of patients with PID.However, it is recommended to perform a chest CT scan each 5 years or before any significant therapeutic change.

The methods of surveillance need to meet two contradictory imperatives:

• monitor frequently enough not to diagnose with delay an aggravation of bronchiectasis or interstitial pneumonitis, an infectious complication by a slowly growing pathogen such as a non-tuberculous mycobacterium, or lymphoid proliferation.
• do not expose these often young patients to significant irradiation by a considerable number of scans during their life. In addition, some patients with PID have increased radiosensitivity without a safe irradiation threshold having been determined.

To make thoses requirements effective, the solution is to combine radiological monitoring and absence of irradiation. Therefore, it makes sense to study whether chest scans can be replaced by MRI, non-irradiating imaging. But the question that needs to be answered is whether the information provided by the chest MRI is not inferior to that provided by the scanner.

The objective of this study is to assess the ability of MRI performed with ultrashort echo time to analyze the extent and severity of bronchial and pulmonary parenchymal lesions during the follow-up of patients with primary immunodeficiency, comparing them to those of the chest CT scan.

Inclusion Criteria:

• Patients aged 18 or over
• Adult patients with PID
• Patients who have performed EFR (Functional Respiratory Tests) within 6 months
• Patients who have signed a consent form
• Patients affiliated with a Health Insurance plan.

Exclusion Criteria:

• Pregnant woman

• Contraindications to MRI:

  • Patients with magnetically activated implanted devices (cardiac pacemakers, insulin pumps, neurostimulators, cochlear implants),
  • Patients with intraocular metal or in the brain (aneurysm clip),
  • Patients with prostheses in the thoracic position and contraindicated for MRI examination
  • Claustrophobic patients.

• To be deprived of liberty or under guardianship.