CAPABILITIES OF MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF SOFT TISSUES SURROUNDING THE UPPER AIRWAY IN PATIENTS WITH OBESITY AND OBSTRUCTIVE SLEEP APNEA SYNDROME

Abstract

Objective: to evaluate the upper airway (UA) soft tissue structures in patients with obesity, comparable body mass index (BMI), and obstructive sleep apnea syndrome (OSAS) varying in severity, by using magnetic resonance imaging (MRI). Material and methods. The results of UA soft tissue MRI were analyzed in 20 patients without obesity and OSAS (a control group), in 42 patients with obesity and severe OSAS (a study group), and in 32 patients with obesity and mild OSAS (a comparison group). MRI scans were used to calculate the volumes of the soft palate (SPV), tongue (TV), lateral pharyngeal walls (LPWV) at the level of the retropharyngeal and retroglossal regions (RPR and RGR), soft tissue amounts (STA) at the level of the RPO and RGR, lingual fat inclusions, as well as lingual fat concentrations, and the area of maximum upper airway stenosis (MUAS) at the level of the RPR and RGR. Results. It was found that in the patients with OSAS, obesity, and comparable BMI, SPV and LPWV at the level of the RPR and RGR, STA at the level of RPR and RGR, and lingual fat inclusions and concentrations were higher in the severe OSAS group than those in the mild OSAS group (p < 0.001). The area of MUAS at the level of RPR and RGR was smaller than that in the mild OSAS group (p < 0.001). Conclusion. In patients with obesity and OSAS, BMI is not always a clear predictor of the degree of severity due to the uneven accumulation of adipose tissue in the soft tissues surrounding the the upper airway.