Diffusion MRI should allow for differentation of pus and simple retention in the paranasal sinuses, but this remained to be determined

On the basis of the apparent diffusion coefficient, the content of a para nasal sinus could be defined as simple mucus or pus. This differentiation is very important for the clinician for prompt treatment. The aim of this study is to retrospectively measure this coefficient and to correlate it to clinica data.

Inclusion Criteria:

• paranasal sinus MRI with a diffusion weighted sequence

Exclusion Criteria:

• no clinical examination available
• no bateriologic sample available

patients with paranasal MRI

MRI is the proprety of the patient