Study On The Correlation Between Dynamic MRI Changes Of Upper Airway And The Severity In Obstructive Sleep Apnea Hypopnea Syndrome Patients

Background and ObjectiveObstructive sleep apnea hypopnea syndrome(OSAHS)is a common disease of the middle-aged and the old,and the prevalence increases with age.Although polysomnography(PSG)is the recognized gold standard for the diagnosis of OSAHS now,the position and cause of the obstruction cannot be detected.The detection of the upper airway and its surrounding tissues plays an important role in locating the position of obstruction accurately and the selection of treatment methods.MRI is the best way for evaluating soft tissue around the airway,and Dynamic MRI can detect the real-time airway morphology,showing the changes of airway morphology and structure intuitively during breathing.Through Dynamic MRI examination for OSAHS patients,the purpose of this study is to explore the changes of cross-sectional area,diameter line and surrounding soft tissue of different regions of the upper airway and to investigate the correlation between the changes of Dynamic MRI in the upper airway and the severity of OSAHS,so as to provide more basis for exploring the pathogenesis,diagnosis and treatment of OSAHS.Subjects and MethodA total of 45 patients who admitted to the First Affiliated Hospital of Zhengzhou University due to sleep disorders from September 2019 to January 2021 and were diagnosed with OSAHS by PSG were included.According to apnea hypopnea index(AHI),a total of 12 patients were divided into the mild-to-moderate OSAHS group,and 33 patients were divided into the severe OSAHS group.On the day of PSG,all patients underwent medical history collection and physical examination.Height,weight and neck circumference were measured,body mass index(BMI)was calculated,and gender,age and history of other diseases were recorded in detail.After completion of PSG,relevant parameters were recorded in detail,including:AHI,the lowest oxygen saturation(LSa02),cumulative percentages of time spent at oxygen saturation below 90%(CT90%),the longest time of apnea and other indicators.All patients underwent Dynamic MRI of upper airway within 3 days after PSG The minimum cross-sectional area,maximum cross-sectional area,minimum left-right diameter,minimum anteroposterior diameter,thickness of lateral pharyngeal wall and thickness of posterior pharyngeal wall of retropalatal region(RP),retrolingual region(RG)and epiglottal region(EPG)were measured in transverse position.The length,thickness and cross-sectional area of the soft palate were measured in the median sagittal position.And the collapsible rate was calculated.The differences in general clinical data and Dynamic MRI parameters between severe OSAHS group and mild-to-moderate OSAHS group were compared.Correlation analysis was used to explore the correlation between Dynamic MRI parameters and PSG parameters.Multiple stepwise regression analysis and binary logistic regression analysis were used to investigate the relationship between Dynamic MRI parameters and the severity of OSAHS.Results1.The neck circumference,AHI,LSaO2,CT90%and the longest time of apnea in the severe OSAHS group were higher than those in the mild-to-moderate OSAHS group,the difference were statistically significant(P<0.05),while the differences in gender,age and BMI were not statistically significant between the two groups(P>0.05).2.Correlation analysis showed that neck circumference was positively correlated with AHI(r=0.576 P=0.005),CT90%(r=0.480 P=0.001),the longest time of apnea(r=0.334 P=0.025),and negatively correlated with LSaO2(r=-0.420 P=0.004).3.There were statistically significant differences in the minimum left-right diameter,minimum anteroposterior diameter,thickness of lateral pharyngeal wall,thickness of posterior pharyngeal wall,minimum cross-sectional area,maximum cross-sectional area and collapsible rate in RP,RG and EPG(P<0.05).The minimum left-right diameter,minimum anteroposterior diameter,minimum cross-sectional area and maximum cross-sectional area of RP were lower than those of RG and EPG,and the differences were statistically significant(P<0.05).The thickness of posterior pharyngeal wall of RP was higher than that of RG(P<0.05),and there was no significant difference in thickness of lateral pharyngeal wall between RP and RG(P>0.05).The thickness of the lateral pharyngeal wall of RP was higher than that of EPG(P<0.05),and there was no statistical significance in thickness of posterior pharyngeal wall of RP and EPG(P>0.05).4.The length,thickness and cross-sectional area of soft palate in the severe OSAHS group were higher than those in the mild-to-moderate OSAHS group,with statistical significance.The thickness of lateral pharyngeal wall and collapsible rate of RP in severe OSAHS group were higher than those in mild-to-moderate OSAHS group,and the minimum left-right diameter,minimum anteroposterior diameter and minimum cross-sectional area of RP in severe OSAHS group were lower than those in mild-to-moderate OSAHS group,with statistical significance(P<0.05).There was no significant difference in thickness of posterior pharyngeal wall and maximum cross-sectional area of RP between the two groups(P>0.05).The thickness of lateral pharyngeal wall and collapsible rate of RG in severe OSAHS group were higher than those in mild-to-moderate OSAHS group,and the minimum left-right diameter,minimum anteroposterior diameter and minimum cross-sectional area of RG in severe OSAHS group were lower than those in mild-to-moderate OSAHS group,with statistical significance(P<0.05).There was no significant difference in thickness of posterior pharyngeal wall and maximum cross-sectional area of RG between the two groups(P>0.05).The thickness of lateral pharyngeal wall and collapsible rate of EPG in severe OSAHS group were higher than those in mild-to-moderate OSAHS group,and the minimum left-right diameter,minimum anteroposterior diameter and minimum cross-sectional area of EPG in severe OSAHS group were lower than those in mild-to-moderate OSAHS group,with statistical significance(P<0.05).There was no significant difference in thickness of posterior pharyngeal wall and maximum cross-sectional area of EPG between the two groups(P>0.05).5.The length of soft palate(r=0.556 P=0.000),thickness of soft palate(r=0.385 P=0.009)and cross-sectional area of soft palate(r=0.574 P=0.000)were positively correlated with AHI,and the length of soft palate(r=0.407 P=0.005)and cross-sectional area of soft palate(r=0.404 P=0.006)were positively correlated with CT90%.The thickness of lateral pharyngeal wall(r=0.551,P=0.000),thickness of posterior pharyngeal wall(r=0.341 P=0.022)and collapsible rate(r=0.501 P=0.000)of RP were positively correlated with AHI,and the minimum left-right diameter(r=-0.580 P=0.001),minimum anteroposterior diameter(r=-0.369 P=0.013)and minimum cross-sectional area(r=-0.525 P=0.000)of RP were negatively correlated with AHI.The thickness of lateral pharyngeal wall(r=-0.536 P=0.000)and thickness of posterior pharyngeal wall(r=-0.378 P=0.011)of RP were positively correlated with CT90%,the minimum left-right diameter of RP(r=-0.354 P=0.017)and minimum cross-sectional area(r=-0.332 P=0.026)of RP were negatively correlated with CT90%.The thickness of lateral pharyngeal wall(r=0.344 P=0.021)and collapsible rate(r=0.445 P=0.002)of RG were positively correlated with AHI,the minimum left-right diameter(r=-0.409 P=0.005),minimum anteroposterior diameter(r=-0.416 P=0.005)and minimum cross-sectional area(r=-0.466 P=0.001)of RG were negatively correlated with AHI.The thickness of lateral pharyngeal wall(r=0.354 P=0.017),collapsible rate(r=0.348 P=0.019)of RG were positively correlated with CT90%,the minimum left-right diameter(r=-0.318,P=0.033)and minimum cross-sectional area(r=-0.353 P=0.017)of RG were negatively correlated with CT90%.The collapsible rate of EPG was positively correlated with AHI(r=0.521 P=0.000),and the minimum left-right diameter(r=-0.409 P=0.005),minimum anteroposterior diameter(r=-0.322 P=0.031)and minimum cross-sectional area(r=-0.399 P=0.007)of EPG were negatively correlated with AHI.The collapsible rate of EPG was positively correlated with CT90%(r=0.340 P=0.022),and the minimum anteroposterior diameter of EPG was negatively correlated with CT90%(r=-0.315,P=0.035).6.The multiple stepwise regression analysis was performed with AHI as the dependent variable and the neck circumference,thickness of lateral pharyngeal wall of RP,minimum cross-sectional area of RP,thickness of lateral pharyngeal wall of RG,minimum cross-sectional area of RG and minimum cross-sectional area of EPG as independent variables.The results showed that neck circumference and minimum cross-sectional area of RP were the main predictors of AHI in OSAHS patients,and the standardized regression coefficients were 0.496(P=0.000)and-0.318(P=0.013),respectively.7.The multiple stepwise regression analysis was performed with CT90%as the dependent variable and the neck circumference,thickness of lateral pharyngeal wall of RP,minimum cross-sectional area of RP,thickness of lateral pharyngeal wall of RG,minimum cross-sectional area of RG and collapsible rate of EPG as independent variables.The results showed that thickness of lateral pharyngeal wall of RP was the main predictor of CT90%in OSAHS patients,and the standardized regression coefficient was 0.412(P=0.005).8.The Logistic regression analysis was performed with severe OSAHS as the outcome variable,and neck circumference,thickness of lateral pharyngeal wall of RP,minimum cross-sectional area of RP,thickness of lateral pharyngeal wall of RG,minimum cross-sectional area of RG and minimum cross-sectional area of EPG as independent variables.The results showed that thickness of lateral pharyngeal wall and minimum cross-sectional area of RP were independent influence factors for severe OSAHS,and the regression coefficients were 0.621(P=0.033)and-0.044(P=0.035),the OR values were 1.861 and 0.957,respectively.Conclusion1.The Dynamic MRI parameters is closely related to the severity of OSAHS.The higher the length of soft palate,thickness of soft palate,cross-sectional area of soft palate,thickness of lateral pharyngeal wall of RP and RQ thickness of posterior pharyngeal wall of RP and collapsible rate,the more severe OSAHS may be.The smaller the minimum left-right diameter,minimum anteroposterior diameter and minimum cross-sectional area of the airway,the more severe OSAHS may be.2.The retropalatal region is the narrowest and most prone to collapse in upper airway,the thickness of lateral pharyngeal wall and minimum cross-sectional area of retropalatal region may be independent influence factors for severe OSAHS.