Ziyue Wu1,2, Weiyi Chen3, Michael C K Khoo1, Sally L Davidson Ward4, Krishna S Nayak1,3. 1. Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA. 2. Alltech Medical Systems America, Solon, Ohio, USA. 3. Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California, USA. 4. Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Abstract
PURPOSE: To develop and demonstrate a real-time MRI method for assessing upper airway collapsibility in sleep apnea. MATERIALS AND METHODS: Data were acquired on a clinical 3 Tesla scanner using a radial CAIPIRIHNA sequence with modified golden angle view ordering and reconstructed using parallel imaging and compressed sensing with temporal finite difference sparsity constraint. Segmented airway areas together with synchronized facemask pressure were used to calculate airway compliance and projected closing pressure, Pclose , at four axial locations along the upper airway. This technique was demonstrated in five adolescent obstructive sleep apnea (OSA) patients, three adult OSA patients and four healthy volunteers. Heart rate, oxygen saturation, facemask pressure, and abdominal/chest movements were monitored in real-time during the experiments to determine sleep/wakefulness. RESULTS: Student's t-tests showed that both compliance and Pclose were significantly different between healthy controls and OSA patients (P < 0.001). The results also suggested that a narrower airway site does not always correspond to higher collapsibility. CONCLUSION: With the proposed methods, both compliance and Pclose can be calculated and used to quantify airway collapsibility in OSA with an awake scan of 30 min total scan room time. J. Magn. Reson. Imaging 2016;44:158-167.
PURPOSE: To develop and demonstrate a real-time MRI method for assessing upper airway collapsibility in sleep apnea. MATERIALS AND METHODS: Data were acquired on a clinical 3 Tesla scanner using a radial CAIPIRIHNA sequence with modified golden angle view ordering and reconstructed using parallel imaging and compressed sensing with temporal finite difference sparsity constraint. Segmented airway areas together with synchronized facemask pressure were used to calculate airway compliance and projected closing pressure, Pclose , at four axial locations along the upper airway. This technique was demonstrated in five adolescent obstructive sleep apnea (OSA) patients, three adult OSApatients and four healthy volunteers. Heart rate, oxygen saturation, facemask pressure, and abdominal/chest movements were monitored in real-time during the experiments to determine sleep/wakefulness. RESULTS: Student's t-tests showed that both compliance and Pclose were significantly different between healthy controls and OSApatients (P < 0.001). The results also suggested that a narrower airway site does not always correspond to higher collapsibility. CONCLUSION: With the proposed methods, both compliance and Pclose can be calculated and used to quantify airway collapsibility in OSA with an awake scan of 30 min total scan room time. J. Magn. Reson. Imaging 2016;44:158-167.
Authors: R Arens; J M McDonough; A T Costarino; S Mahboubi; C E Tayag-Kier; G Maislin; R J Schwab; A I Pack Journal: Am J Respir Crit Care Med Date: 2001-08-15 Impact factor: 21.405
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