Nasal polyposis (NP) is a disease affecting 4% of the population. This disease is frequently accompanied by olfactory disorders (41%-84% of patients) that affect patients' quality of life.

The aim of this study is to show brain activity differences in olfactory areas before and after surgery in each patient and between patient groups (normosmic, hyposmic and anosmic one) using functional Magnetic Resonance Imaging (fMRI). Brain activity will be measured by the intensity of brain signals and of the size of olfactory areas during olfactory stimulation before and after surgery. We suppose that fMRI could predict whether or not the patient will be able to recover smell after surgery.

Inclusion Criteria:

• Patients with nasal polyposis managed in the department of otorhinolaryngology and head and neck surgery of Nancy University Hospital,
• Adult Patients,
• Justifying a surgical treatment for nasal polyposis,
• Present hyposmia, anosmia or normosmia before surgery (confirmed by threshold and identification tests of the Sniffin' Stick kit),
• Affiliated with or beneficiary of a social security scheme,
• Having received complete information about the study and having signed an informed consent form.

Exclusion Criteria:

• General contraindications to Magnetic Resonance Imaging,
• Female of childbearing age without effective contraception,
• Persons referred in Articles L. 1121-5 to L. 1121-8 and L1122-2 of the Public Health Code,
• Qualitative sense of smell disorder (cacosmia, hyperosmia, phantosmia, parosmia),
• Smell disorders with neurological, post-traumatic, or neurodegenerative origin.