Efficacy of dynamic MRI sleep study in the management of obstructive sleep apnea: an observational study

Background: Obstructive sleep apnea has become a more common health problem owing to a more sedentary lifestyle and work culture. Dynamic MRI in the preoperative evaluation of these patients aims at diagnosing the actual cause, level and pattern of obstruction and guides the surgeon in decision making among the various treatment options established. Methods: In this retrospective study, Dynamic MRI was performed in 66 patients who were previously diagnosed with polysomnography. The levels and pattern of obstruction were analysed with the severity of AHI grading and their significance in planning the treatment protocol is discussed. Results: 62 patients had significant retropalatal collapse and 53 had lateral pharyngeal wall collapse in the Dynamic MRI. Retroglossal collapse is usually presenting with the retropalatal collapse and are found in six patients. Collapse at all three levels namely retropalatal, retroglossal and hypopharyngeal are present in three patients. 48 patients were advised for surgical management after pre-operative evaluation with MRI and 30 patients who underwent surgery had promising results at the six month follow up visit. Conclusion: This study shows that lateral pharyngeal wall collapse is majorly contributory to the AHI severity although multilevel collapse is seen in both mild and severe OSA patients. Hence, Dynamic MRI is suggested before proceeding with the management of the OSA patients.