[Clinical application of the dynamic adenoidal hypertrophy ratio in the evaluation of illness severity in children with OSAHS].

To evaluate application value of the dynamic adenoidal/hypertrophy (A/N) ratio in children with OSAHS by analyzing the correlation between the A/N ratio at the different respiratory phases and the index of polysomnography.Fifty-one childrens, with simple hypertrophic adenoids, were diagnosed as OSAHS. Magnetic resonance imaging (MRI) with respiratory gating technology were used to scan the upper airway of children during sleep at the early, middle and end phases of respiratory cycle, and measure adenoidal hypertrophy ratio in different respiratory phases. The correlation analysis was performed between the A/N ratio in different respiratory phases and the index of polysomnography (AHI and LaSO2). Finally, via ROC curve and Kappa analysis, the critical value and diagnosis accordance rate of A/N ratio in illness severity evaluation of children with OSAHS were confirmed.At the 6 respiratory phases, the A/N ratios showed significantly positive correlations with AHI (All < 0.01). There was a highest coefficient between the end-expiratory A/N ratio and AHI (= 0.559 4). In addition, the optimal cut-off point of A/N ratio between slight-moderate and severe OSAHS was 0.834. The diagnosis accuracies of the end-expiratory A/N ratio in severe and slight moderate OSAHS were 81% and 84%, respectively.MRI with respiratory gating technology obtaining dynamic A/N ratio might be an important method of imaging diagnosis of children OSAHS, and the end expiratory A/N ratio is expected to become a classification index of slight moderate and severe children OSAHS.