Share Email Print
cover

Proceedings Paper

Xenon gas flow patterns evaluated by high-speed multi-row detector CT
Author(s): Deokiee Chon; Ken C. Beck; Hidenori Shikata; Osama I. Saba; Brett A. Simon; Chulho Won; Eric A. Hoffman
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Regional lung ventilation can be measured via Xenon-enhanced computed tomography (Xe-CT) by determining washin (WI) and washout (WO) rates of stable Xe. It has been assumed that WI = WO, ignoring Xe solubility in blood and tissue and then other geometric isssues. We test this by measuring WO-WI in lung by Xe-CT. Also, we investigate the effect of tidal volume (TV) and end inspiratory (EI) vs end expiratory (EE) scan gating on WO and WI measurements. 3 anesthetized, supine sheep were scanned using multidetector-row computed tomography (MDCT). Imaging was gated to both EE and EI during a WI (33 breaths) and WO (20 breaths) maneuver using 55% Xe for WI and room air for WO. Time constants (TCs) of Xe WI and WO were obtained by exponential fitting. WO and WI TCs were compared: 1) apex and base 2) dependent, middle, and nondependent 3) EE and EI 4) three TVs. The vertical gradient of WO-WI showed WO > WI in dependent vs non-dependent regions. WO-WI in both dependent and nondependent region at the lung base and apex was larger when measured at EE compared to EI. As TV increases, the global WO-WI difference decreased. TV showed greater influence on WO than WI. Xe WO was longer than WI possibly reflecting Xe solubility in blood and tissue. Higher TVs and gating to EE provided greater effects on WO than WI TCs which may relate to the number of partial volumed conducting airways contributing to the regional voxel-based measures. We conclude that WO mode is more susceptible to errors caused by either xenon solubility or tidal volume than WI mode and EE scanning may more accurately reflect alveolar ventilation.

Paper Details

Date Published: 30 April 2004
PDF: 11 pages
Proc. SPIE 5369, Medical Imaging 2004: Physiology, Function, and Structure from Medical Images, (30 April 2004); doi: 10.1117/12.535845
Show Author Affiliations
Deokiee Chon, Univ. of Iowa (United States)
Ken C. Beck, Univ. of Iowa (United States)
Hidenori Shikata, Univ. of Iowa (United States)
Osama I. Saba, Univ. of Iowa (United States)
Brett A. Simon, Johns Hopkins Univ. (United States)
Chulho Won, Univ. of Iowa (United States)
Eric A. Hoffman, Univ. of Iowa (United States)


Published in SPIE Proceedings Vol. 5369:
Medical Imaging 2004: Physiology, Function, and Structure from Medical Images
Amir A. Amini; Armando Manduca, Editor(s)

© SPIE. Terms of Use
Back to Top