Laryngoscope 118(8) August 2008

Link to journal
Barkdull, Gregory C. ; Kohl, Chad A. ; Patel, Minal ; Davidson, Terence M.
Computed Tomography Imaging of Patients With Obstructive Sleep Apnea
p.1486-1492
Abstract
Objectives/Hypothesis: This study used computed tomography (CT) to identify anatomic features of the awake upper respiratory tract (URT) that correlate with severity of obstructive sleep apnea (OSA).Study Design: An IRB approved radiographic study of 80 patients with OSA and 56 patients from the general population.Methods: Awake, noncontrast CT was performed from the skull base to the thoracic inlet in patients with OSA. Cross-sectional measurements of the retropalatal and retrolingual airways were made along with the size of the cervicomandibular ring and the percentage neck fat. The mandibular plane to hyoid distance, neck length, and laryngeal descent were also recorded. The posterior tongue fat content was estimated using the Hounsfield unit for radiodensity. The radiographic data were then compared with clinical information, including apnea-hypopnea index (AHI), body mass index, and neck circumference using linear regression.Results: AHI increases with smaller retrolingual cross-sectional airway (P = .0026) and increasing mandibular plane to hyoid distance (P = .0003) but not retropalatal airway or laryngeal descent. The posterior tongue is hypodense with higher fat content than other muscles of the head and neck.Conclusions: This study describes anatomic findings of the retrolingual airway in patients that correlate with OSA and can be measured on an upper airway CT. Patients with severe OSA (AHI >=40) tend to have retrolingual airways less than 4% of the cross-sectional area of the cervicomandibular ring. The retrolingual airspace is the major site of obstruction in severe OSA and should be carefully evaluated before surgical treatment is considered.(C) The American Laryngological, Rhinological & Otological Society, Inc.

Yoshida, Tadao ; Sugiura, Makoto ; Naganawa, Shinji ; Teranishi, Masaaki ; Nakata, Seiichi ; Nakashima, Tsutomu
Three-Dimensional Fluid-Attenuated Inversion Recovery Magnetic Resonance Imaging Findings and Prognosis in Sudden Sensorineural Hearing Loss
p.1433-1437
Abstract
Objectives/Hypothesis: Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) has recently been developed to detect high concentrations of protein or hemorrhage. We have previously reported that 50% of patients with sudden sensorineural hearing loss (SNHL) show high signals in the affected inner ear on 3D-FLAIR MRI. However, the relationship between 3D-FLAIR findings and hearing prognosis is unclear. Our objective was to evaluate the relationship between the results of 3D-FLAIR MRI at 3 Tesla and prognosis in sudden SNHL.Study Design and Methods: We used 3D-FLAIR at 3 Tesla with and without gadolinium enhancement to evaluate the pathologic conditions in the inner ears of 48 patients with sudden SNHL.Results: Thirty-one of 48 patients with sudden SNHL showed high signals in the affected inner ear on precontrast 3D-FLAIR. Hearing improvement in patients with high signals in the affected inner ear on precontrast 3D-FLAIR (25 +/- 19 dB) was significantly worse than that in patients with no signal (45 +/- 27 dB; P < .05). Our analysis suggests that high signals in the affected inner ear on precontrast 3D-FLAIR MRI is a new prognostic factor for sudden SNHL.Conclusions: 3D-FLAIR findings show that high signals in the cochlea on precontrast 3D-FLAIR are related to a poor hearing prognosis. These signals may reflect minor hemorrhage or an increased concentration of protein in the inner ear, which has passed through blood vessels with increased permeability or has originated in disrupted cells in the inner ear.