Synchronized imaging and acoustic analysis of the upper airway in patients with sleep-disordered breathing.
Progressive narrowing of the upper airway increases airflow resistance and can produce snoring sounds and apnea/hypopnea events associated with sleep-disordered breathing due to airway collapse. Recent studies have shown that acoustic properties during snoring can be altered with anatomic changes at the site of obstruction. To evaluate the instantaneous association between acoustic features of snoring and the anatomic sites of obstruction, a novel method was developed and applied in nine patients to extract the snoring sounds during sleep while performing dynamic magnetic resonance imaging (MRI). The degree of airway narrowing during the snoring events was then quantified by the collapse index (ratio of airway diameter preceding and during the events) and correlated with the synchronized acoustic features. A total of 201 snoring events (102 pure retropalatal and 99 combined retropalatal and retroglossal events) were recorded, and the collapse index as well as the soft tissue vibration time were significantly different between pure retropalatal (collapse index, 2 ± 11%; vibration time, 0.2 ± 0.3 s) and combined (retropalatal and retroglossal) snores (collapse index, 13 ± 7% [P ≤ 0.0001]; vibration time, 1.2 ± 0.7 s [P ≤ 0.0001]). The synchronized dynamic MRI and acoustic recordings successfully characterized the sites of obstruction and established the dynamic relationship between the anatomic site of obstruction and snoring acoustics.
Research Center for Adaptive Data Analysis and Center for Dynamical Biomarkers and Translational Medicine, National Central University, Chungli, Taiwan. Graduate Institute of Communication Engineering, National Taiwan University, Taipei, Taiwan.
Yi-Chung
YC
Chang
Leh-Kiong
LK
Huon
Van-Truong
VT
Pham
Yunn-Jy
YJ
Chen
Sun-Fen
SF
Jiang
Tiffany Ting-Fang
TT
Shih
Thi-Thao
TT
Tran
Yung-Hung
YH
Wang
Chen
C
Lin
Jenho
J
Tsao
Men-Tzung
MT
Lo
Pa-Chun
PC
Wang
D000162:Acoustics; D000328:Adult; D000402:Airway Obstruction / Q000150:complications; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012119:Respiration; D012137:Respiratory System / Q000503:physiopathology*; D012893:Sleep Wake Disorders / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D013997:Time Factors