HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (26) Citing Articles via Google Scholar Google Scholar Articles by Ciscar, M.A. Articles by Basterra, J. Search for Related Content PubMed PubMed Citation Articles by Ciscar, M.A. Articles by Basterra, J.

Magnetic resonance imaging of the pharynx in OSA patients and healthy subjects

¹ Service of Pneumology, ² Unit of Computerized Tomography and Magnetic Resonance Imaging, and ³ Service of Otorhinolaryngology, Hospital General Universitario de Valencia, Valencia, Spain, ⁴ Service of Pneumology, Hospital Luis Alcañiz, Játiva, Spain, and ⁵ Service of Pneumology, Hospital Clínico Universitario de Valencia, Valencia, Spain

CORRESPONDENCE: G. Juan, Servicio de Neumologia, Hospital General Universitario de Valencia, Avda Tres Cruces s/n 46014, Valencia, Spain. Fax: 34 963798306

This study was supported by GlaxoWellcome.

Obstructive sleep apnoea (OSA) occurs because of recurrent narrowing and occlusion of the velopharynx (VP) during sleep. The specific cause of OSA is unknown. Cephalometric radiography, fibreoptic nasopharyngoscopy, acoustic reflection techniques, and computerized tomography have limitations (dynamic and tridimensional evaluation) in the mechanism of occlusion investigation. Static and dynamic examination of the soft tissue structures surrounding the upper airway during the respiratory cycle in wakefulness and sleep, can lead to a better understanding of the process.

Ultrafast magnetic resonance imaging (one image per 0.8 s) was used to study the upper airway and surrounding soft tissue in 17 patients with OSA during wakefulness and sleep, and in eight healthy subjects whilst awake.

The major findings of this investigation in the 25 subjects were as follows: 1) the VP was smaller in apnoeic patients, only during part of the respiratory cycle; 2) the variation in VP area during the respiratory cycle was greater in apnoeic patients than in controls, particularly during sleep, suggesting an increased compliance of the VP in these patients; 3) VP narrowing was similar in the lateral and anterior-posterior dimensions, both in controls and apnoeic patients while awake; apnoeic patients during sleep have a more circular VP upon reaching the minimum area; 4) there was an inverse relationship between dimensions of the lateral pharyngeal walls and airway area, probably indicating that lateral walls are passively compressed or stretched as a result of changes in the airway calibre; and 5) soft palate and parapharyngeal fatpads were larger in apnoeic patients, although their role in the genesis of OSA is uncertain.

It was concluded that changes in the velopharynx area and diameter during the respiratory cycle are greater in apnoeic patients than in normal subjects, particularly during sleep. This suggests that apnoeic patients have a more collapsible velopharynx, this being the main mechanism of obstruction.

Keywords: magnetic resonance imaging, obstructive sleep apnoea, sleep, velopharynx, wakefulness