Xenon-Enhanced Dynamic Dual-Energy CT Is Able to Quantify Sinus Ventilation Using Laminar and Pulsating Air-/Gas Flow Before and After Surgery: A Pilot Study in a Cadaver Model.

Sven Becker,Thorsten R Johnson,Anne Merle Becker,Tilman Huppertz,Winfried Möller,Martin Sailer,Maria Schuster,Miriam Havel,Uwe Schuschnig

doi:10.3389/falgy.2022.829898

Abstract

BackgroundChronic rhinosinusitis is a common disease with a significant impact on the quality of life. Topical drug delivery to the paranasal sinuses is not efficient to prevent sinus surgery or expensive biologic treatment in a lot of cases as the affected mucosa is not reached. More efficient approaches for topical drug delivery are, therefore, necessary. In the current study, dual-energy CT (DECT) imaging was used to examine sinus ventilation before and after sinus surgery using a pulsating xenon gas ventilator in a cadaver head.MethodsXenon gas was administered to the nasal cavity of a cadaver head with a laminar flow of 7 L/min and with pulsating xenon-flow (45 Hz frequency, 25 mbar amplitude). Nasal cavity and paranasal sinuses were imaged by DECT. This procedure was repeated after functional endoscopic sinus surgery (FESS). Based on the enhancement levels in the different sinuses, regional xenon concentrations were calculated.ResultsXenon-related enhancement could not be detected in most of the sinuses during laminar gas flow. By superimposing laminar flow with pulsation, DECT imaging revealed a xenon wash-in and wash-out in the sinuses. After FESS, xenon enhancement was immediately seen in all sinuses and reached higher concentrations than before surgery.ConclusionXenon-enhanced DECT can be used to visualize and quantify sinus ventilation. Pulsating air-/gas flow was superior to laminar flow for the administration of xenon to the paranasal sinuses. FESS leads to successful ventilation of all paranasal sinuses.

Highlights

Chronic rhinosinusitis (CRS) is a common disease affecting approximately 15% of the population in western countries [1, 2]
Beginning with laminar airflow with room air at 0 s and with 100% xenon from 10.5 s onward, a rise in xenon concentration could be detected in both nasal cavities reaching a plateau at around 20 s (Figure 3, blue and black line)
Nasal cavity is filled with nearly 100% xenon gas corresponding to −750 Hounsfield units (HU)

Summary

Introduction

Chronic rhinosinusitis (CRS) is a common disease affecting approximately 15% of the population in western countries [1, 2]. To better estimate treatment success, knowledge about sinus ventilation could be helpful when using topical corticosteroids in form of an aerosol generated by a nebulizer. To improve gas and aerosol transport into the sinuses pressure gradients between the two sides of the ostia are necessary [6, 7]. This effect can be attained with a pulsating airflow generated by nebulization devices [7,8,9,10,11]. Topical drug delivery to the paranasal sinuses is not efficient to prevent sinus surgery or expensive biologic treatment in a lot of cases as the affected mucosa is not reached. Dual-energy CT (DECT) imaging was used to examine sinus ventilation before and after sinus surgery using a pulsating xenon gas ventilator in a cadaver head

Methods

Results

Conclusion