Quantifying diaphragm blood flow with contrast-enhanced ultrasound in healthy humans : feasibility, validity, and reliability
department or school: Health and Social Development, Faculty of (Okanagan)
department or school: Health and Exercise Sciences, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Bird, Jordan Douglas
issued: 2024-09-01T07:00:00Z
issued: 2023
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Current understanding of diaphragm blood flow (Q̇DIA) is almost exclusively informed by animal models with no viable method of routinely interrogating Q̇DIA in humans. We aimed to assess the feasibility, validity, and reliability of contrast-enhanced ultrasound (CEUS) as a means of quantifying Q̇DIA within the medial costal diaphragm of humans during graded inspiratory pressure threshold loading (ITL). We hypothesized that 1) Q̇DIA would linearly increase with respiratory muscle work and 2) that there would be good test-retest reliability and inter-observer reliability of CEUS as a measure of Q̇DIA. Quantitative CEUS perfusion imaging of the medial diaphragm was performed in sixteen healthy participants (10M/6F; Age 28±5 yrs; BMI 22.8 ± 2.0 kg/m2) at the 8-10th right intercostal space. Respiratory muscle work was modulated by four 5-minute bouts of ITL (baseline, stage 1, stage 2, stage 3). Nasogastric balloon catheters were used to collect transdiaphragmatic pressures and calculate diaphragmatic work. CEUS was performed during a constant-rate intravenous infusion of lipid-stabilized microbubbles during the last two minutes of each level of ITL. CEUS images were acquired after a destruction-replenishment sequence and time-intensity data was measured from regions of interest placed over the diaphragm to determine Q̇DIA. %MIP for baseline (BL), stage 1 (S1), stage 2 (S2), and stage 3 (S3) were 0.7 ± 0.4, 9.3 ± 0.4, 17.6 ± 0.4, and 25.2 ± 0.4%, respectively. Q̇DIA significantly increased with ITL (3.1 ± 3.1 vs, 6.9 ± 3.6 vs, 11.0 ± 4.9 vs, 13.5 ± 5.4 AU·s-1) at BL, S1, S2, and S3 (all P < 0.01). There was a reproducible linear relationship between Q̇DIA and diaphragmatic work from day-to-day. There was good-to-excellent test-retest (ICC = 0.86 [0.77, 0.92]; P < 0.0001) and inter-observer (ICC = 0.93 [0.90, 0.95]; P < 0.0001) reliability for Q̇DIA. Mean differences with 95% limits of agreements for Q̇DIA were 0.6 ± 6.1 AU·s⁻¹ and 0.1 ± 4.4 AU·s⁻¹ for test-retest and int…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/85987
note: 1 QUANTIFYING DIAPHRAGM BLOOD FLOW WITH CONTRAST-ENHANCED ULTRASOUND IN HEALTHY HUMANS: FEASIBILITY, VALIDITY, AND RELIABILITY by Jordan Douglas Bird B.HSc., Mount Royal University, 2019 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Health & Exercise Sciences) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) September 2023 © Jordan Douglas Bird, 2023 2 The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, the thesis entitled: Quantifying Diaphragm Blood Flow with Contrast-Enhanced Ultrasound in Healthy Humans: Feasibility, Validity, and Reliability submitted by Jordan D. Bird in partial fulfilment of the requirements for the degree of Masters of Science in Health & Exercise Sciences Examining Committee: Dr. Glen Foster, School of Health & Exercise Sciences, UBC Okanagan Supervisor Dr. Neil Eves, School of Health & Exercise Sciences, UBC Okanagan Supervisory Committee Member Dr. Paolo Dominelli, Department of Kinesiology & Health Sciences, University of Waterloo Supervisory Committee Member Dr. Jordan Guenette, School of Kinesiology, UBC Vancouver University Examiner 3 Abstract Current understanding of diaphragm blood flow (Q̇DIA) is almost exclusively informed by animal models with no viable method of routinely interrogating Q̇DIA in humans. We aimed to assess the feasibility, validity, and reliability of contrast-enhanced ultrasound (CEUS) as a means of quantifying Q̇DIA within the medial costal diaphragm of humans during graded inspiratory pressure threshold loading (ITL). We hypothesized that 1) Q̇DIA would linearly increase with respiratory muscle work and 2) that there would be good test-retest reliability and inter-observer reliability of CEUS as a measure of Q̇DIA. Quantitative CEUS perfusion imaging of the medial diaphragm was performed in sixteen healthy participants (10M/6F; Age 28±5 yrs; BMI 22.8 ± 2.0 kg/m…
has type: Thesis/Dissertation
date issued: 2023-11
is shown at: 10.14288/1.0435936
language: eng
degree discipline: Health and Exercise Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Foster, Glen E.
type: Text
identifier URI: http://hdl.handle.net/2429/85987