ObjectivesPatients with eosinophilic chronic rhinosinusitis with nasal polyps (eosCRSwNP) usually have more extensive sinus disease, severe symptoms, and poorer disease control compared with patients with non-eosCRSwNP. Separating these entities will be crucial for patient management. The purpose of this study is to investigate T-1,T- T-2, and apparent diffusion coefficient (ADC) values of the nasal polyps in patients with CRSwNP and evaluate the usefulness of these parameters for differentiating these diseases.MethodsSinonasal magnetic resonance imaging was performed in 36 patients with eosCRSwNP and 20 patients with non-eosCRSwNP (including T-1 mapping, T-2 mapping, and diffusion-weighted imaging) before surgery. The T-1, T-2, and ADC values were calculated and correlated with pathologically assessed inflammatory cells of nasal polyps.ResultsSignificant higher T-2 value, higher eosinophil count, and lower lymphocyte count of the nasal polyps were observed in eosCRSwNP than those in non-eosCRSwNP. There was no significant difference in T-1 or ADC values between the 2 groups. T-2 value was correlated with eosinophil count and lymphocyte count in CRSwNP. The area under the curve of T-2 value for predicting eosCRSwNP was 0.78 with 89.9% sensitivity and 60.0% specificity.ConclusionT(2) value is a promising imaging biomarker for predicting eosCRSwNP. It can help to distinguish eosCRSwNP from non-eosCRSwNP.