title: Improved sleep MRI at 3 tesla in patients with obstructive sleep apnea.
abstract: OBJECTIVE
  To describe a real-time MR imaging platform for synchronous, multi-planar visualization of upper airway collapse in obstructive sleep apnea at 3 Tesla (T) to promote natural sleep with an emphasis on lateral wall visualization.
  
  
  METHODS
  A real-time imaging platform was configured for sleep MR imaging which used a cartesian, partial k-space gradient-echo sequence with an inherent temporal resolution of 3 independent slices every 2 s. Combinations of axial, mid-sagittal, and coronal scan planes were acquired. The system was tested in five subjects with polysomnography-proven obstructive sleep apnea during sleep, with synchronous acquisition of respiratory effort and combined oral-nasal airflow data.
  
  
  RESULTS
  Sleep was initiated and maintained to allow demonstration of sleep-induced, upper airway collapse as illustrated in two subjects when using a real-time, sleep MR imaging platform at 3T. Lateral wall collapse could not be visualized on mid-sagittal imaging alone and was best characterized on multiplanar coronal and axial imaging planes.
  
  
  CONCLUSIONS
  Our dedicated sleep MR imaging platform permitted an acoustic environment of constant "white noise" which was conducive to sleep onset and sleep maintenance in obstructive sleep apnea patients at 3T. Apneic episodes, specifically the lateral walls, were more accurately characterized with synchronous, multiplanar acquisitions.
authors: Department of Radiology, Stanford University, Stanford, California, USA; VA Palo Alto Health Care System, Palo Alto, California, USA.
authors: Lewis K
authors: LK
authors: Shin
authors: Andrew B
authors: AB
authors: Holbrook
authors: Robson
authors: R
authors: Capasso
authors: Clete A
authors: CA
authors: Kushida
authors: Nelson B
authors: NB
authors: Powell
authors: Nancy J
authors: NJ
authors: Fischbein
authors: Kim Butts
authors: KB
authors: Pauly
mesh_terms: D000328:Adult; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007830:Larynx / Q000473:pathology*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000473:pathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology* / Q000503:physiopathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012890:Sleep
keywords: multi-slice MRI; obstructive sleep apnea; real-time MRI; sleep MRI