Retrospective analysis of sinus CT scans images from individuals (period 2016-2019)  Inclusion Criteria:  All individuals (>18 years all) with a sinus CT scan available in the CHRU database  Exclusion Criteria:  inflammatory sinus disease (eg. nasal polyposis, aspergilloma, ...) evolutive sinus tumor anatomical abnormality (e.g. post traumatic, prior sinus surgery, embryologic abnormality...)