title: Fluoroscopic MR of the pharynx in patients with obstructive sleep apnea.
abstract: OBJECTIVE
  The purpose of our study was to introduce an ultrafast MR imaging technique of the pharynx as a diagnostic tool for viewing the mechanism of obstruction in patients with obstructive sleep apnea.
  
  
  METHODS
  Six healthy volunteers and 16 patients with obstructive sleep apnea were examined on a 1.5-T whole-body imager using a circular polarized head coil. Ultrafast two-dimensional fast low-angle shot sequences were obtained in midsagittal and axial projections during transnasal shallow respiration at rest, during simulation of snoring, and during performance of the Müller maneuver. All patients underwent physical examination, transnasal fiberoptic endoscopy, and polysomnography.
  
  
  RESULTS
  Five to six images were obtained per second with an in-plane resolution of 2.67 x 1.8 mm and 2.68 x 2.34 mm, allowing visualization of motion of the tongue, soft palate, uvula, and posterior pharyngeal surface. MR findings correlated well with results of clinical examination. The length of obstruction in the oropharynx, which cannot be ascertained by transnasal endoscopy of the pharynx, was clearly visible MR images. Differences between patients with obstructive sleep apnea and healthy subjects in terms of the degree of obstruction in the velopharynx and oropharynx depicted on MR images during the Müller maneuver were highly significant.
  
  
  CONCLUSIONS
  We believe that ultrafast MR imaging is a reliable noninvasive method for use in the evaluation of obstructive sleep apnea.
authors.affiliation: Department of Radiology, Institut für Radiologische Diagnostik, Klinikum Grosshadern, Ludwig-Maximilians-Universität München, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Jäger
authors.forename: E
authors.initials: E
authors.lastname: Günther
authors.forename: J
authors.initials: J
authors.lastname: Gauger
authors.forename: M
authors.initials: M
authors.lastname: Reiser
mesh_terms: D000402:Airway Obstruction / Q000473:pathology* / Q000503:physiopathology; D004724:Endoscopy; D005069:Evaluation Studies as Topic; D005471:Fluoroscopy; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D001239:Inhalation / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D009666:Nose / Q000502:physiology; D009960:Oropharynx / Q000473:pathology / Q000503:physiopathology; D010160:Palate, Soft / Q000473:pathology / Q000503:physiopathology; D010614:Pharynx / Q000473:pathology* / Q000503:physiopathology; D010808:Physical Examination; D017286:Polysomnography; D015203:Reproducibility of Results; D012119:Respiration; D012146:Rest / Q000502:physiology; D012891:Sleep Apnea Syndromes / Q000473:pathology* / Q000503:physiopathology; D012913:Snoring / Q000473:pathology / Q000503:physiopathology; D014059:Tongue / Q000473:pathology / Q000503:physiopathology; D014609:Uvula / Q000473:pathology / Q000503:physiopathology