Open AccessAssessment by airway ellipticity on cine‐MRI to differentiate severe obstructive sleep apnea
Author(s) -
Kojima Tsukasa,
Kawakubo Masateru,
Nishizaka Mari K.,
Rahmawati Anita,
Ando Shinichi,
Chishaki Akiko,
Nakamura Yasuhiko,
Nagao Michinobu
Publication year - 2018
Publication title -
the clinical respiratory journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.789
H-Index - 33
eISSN - 1752-699X
pISSN - 1752-6981
DOI - 10.1111/crj.12598
Subject(s) - medicine , polysomnography , obstructive sleep apnea , receiver operating characteristic , airway , apnea , wilcoxon signed rank test , cutoff , sleep apnea , cardiology , anesthesia , mann–whitney u test , physics , quantum mechanics
The severity of obstructive sleep apnea (OSA) is assessed by the apnea–hypopnea index (AHI) determined from polysomnography (PSG). However, PSG requires a specialized facility with well‐trained specialists and takes overnight. Therefore, simple tools, which could distinguish severe OSA, have been needed before performing PSG. Objectives We propose the new index using cine‐MRI as a screening test to differentiate severe OSA patients, who would need PSG and proper treatment. Methods Thirty‐six patients with suspected OSA (mean age 54.6 y, mean AHI 52.6 events/h, 33 males) underwent airway cine‐MRI at the fourth cervical vertebra level during 30 s of free breathing and PSG. The minimum airway ellipticity (AE) in 30 s duration was measured, and was defined as the severity of OSA. Patients were divided into severe OSA, not‐severe OSA, and normal groups, according to PSG results. The comparison of AE between any two of the three groups was performed by Wilcoxon rank‐sum test. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cut‐off of AE for identifying severe OSA patients. Results The minimum AE for severe OSA was significantly lower than that for not‐severe OSA and normal (severe, 0.17 ± 0.16; not severe, 0.31 ± 0.17; normal, 0.38 ± 0.19, P < .05). ROC analysis revealed that the optimal cutoff of the minimum AE 0.21 identified severe OSA patients, with an area under the curve of 0.75, 68% sensitivity, and 83% specificity. Conclusion AE is a feasible quantitative index, and a promising screening test for detecting severe OSA patients.