Modal Anatomy of the Ethmoid Bone

Study Overview
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Brief Summary
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The creation of a 3D model of modal anatomy of the ethmoid could, like other parts of the body, improve anatomical, radiological and perhaps even surgical learning. Anatomical variations might constitute a background noise of the modal anatomy, which can be attenuated by multiplying the instances of acquisitions. The objective of this work is to establish modal anatomy of the ethmoid by the analysis of a large number of CT-scan acquisitions carried out in individuals with no acquired sinus pathology.

Detailed Description
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Non-interventional descriptive research. Sinus CTscans (period 2016-2019) will be reviewed from the PACS database of the CHRU of Nancy and selected in individuals without sinus pathology. All CT-scans will be fully anonymized. 26 landmarks will be pointed out to enable : prior images alignment (centering on the median line, realignment rotations then resizing) a mean and median calculation, allowing to establish a mean and median ethmoid model calculation of standard deviations for each voxel The structures obtained in this way (bone, tissue or aerial) will be described anatomically.

Official Title
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Constitution d'un modèle 3D d'Anatomie Modale de L'Ethmoide Par intégration de Multiples Instances d'Acquisition

Conditions
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Anatomic Abnormality

Intervention / Treatment
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* Other: No intervention


Participation Criteria
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Eligibility Criteria
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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...)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| CT scans<br>No intervention Data of voxels will be integrated to the final model | Other: No intervention<br>* No intervention<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Descriptive study of the anatomy of the final 3D model | Descriptive study The study aims to produce the modal (generic) model from all the individual sub-models. The structures obtained will be described anatomically by ENT experts: the created model will be described in comparison with anatomical data from literature: constant structures (e.g. middle turbinate, inferior turbinate, or orbital wall) will be listed and described (sites of insertion, direction, form), while variations in anatomical structures will be described through the variance (variances of voxels, pooled for each anatomical sub-site) (e.g. anterior ethmoid, sphenoid...). The heat map of voxels' variances will be superposed on the final model. No scale/physiological parameter/questionnaire can be used for anatomical description of a single model. Therefore we don't really understand your remark Please further specify the measurement that will be used (e.g., descriptive name of scale, physiological parameter, questionnaire) to assess this outcome measure. | Through completion of the study: 1 month (The model will be available only at the end of the study, after implementation of all CT-scans) |