title: Quantitative assessment of the pharyngeal airway by dynamic magnetic resonance imaging in obstructive sleep apnea syndrome.
abstract: Dynamic changes in the pharyngeal airway of patients with obstructive sleep apnea syndrome (OSAS) were evaluated by quantitating the findings of real-time imaging performed during wakefulness and spontaneous sleep by means of dynamic magnetic resonance imaging (MRI). Six patients with OSAS and 3 non-OSAS subjects, selected prospectively and randomly, underwent polysomnography and dynamic MRI. The cross-sectional areas of the soft palate and oropharynx and the anterior-posterior airway dimensions seen during wakefulness and spontaneous sleep were calculated by US National Institutes of Health imaging software. On the basis of a case control study, comparisons were made with age-matched and body mass index-matched obese non-OSAS snorers. Spontaneous sleep caused significant obstruction and narrowing of various sites of the pharyngeal airway in the OSAS patients, but not in the non-OSAS subjects. During wakefulness, the non-OSAS subjects showed no marked narrowing of the pharyngeal airways, whereas a transient but significant narrowing was observed in the OSAS patients. The mean values of both the cross-sectional area and the anterior-posterior diameter at the soft palate were significantly reduced by spontaneous sleep in the OSAS patients. Dynamic MRI in awake OSAS patients shows promise as a routine diagnostic tool for localizing the upper airway collapse for appropriate selection of surgical therapy.
authors.affiliation: Department of Otorhinolaryngology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: M
authors.initials: M
authors.lastname: Ogura
authors.forename: T
authors.initials: T
authors.lastname: Oshima
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Higano
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Kurosawa
authors.forename: W
authors.initials: W
authors.lastname: Hida
authors.forename: H
authors.initials: H
authors.lastname: Matsuoka
authors.forename: T
authors.initials: T
authors.lastname: Takasaka
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000145:classification / Q000150:complications / Q000175:diagnosis; D010160:Palate, Soft / Q000502:physiology; D010614:Pharynx / Q000502:physiology / Q000503:physiopathology*; D017286:Polysomnography / Q000379:methods; D011446:Prospective Studies; D012890:Sleep / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D014851:Wakefulness / Q000502:physiology