Lookup NU author(s): Dr Mary Neal,
Dr Benjamin Pippard,
Professor John Simpson,
Dr Peter Thelwall
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2019 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in MedicinePurpose: To assess alveolar perfusion by applying dynamic susceptibility contrast MRI to 19F-MRI of inhaled perfluoropropane (PFP). We hypothesized that passage of gadolinium-based contrast agent (GBCA) through the pulmonary microvasculature would reduce magnetic susceptibility differences between water and gas components of the lung, elevating the T* 2 of PFP. Methods: Lung-representative phantoms were constructed of aqueous PFP-filled foams to characterize the impact of aqueous/gas phase magnetic susceptibility differences on PFP T* 2. Aqueous phase magnetic susceptibility was modulated by addition of different concentrations of GBCA. In vivo studies were performed to measure the impact of intravenously administered GBCA on the T* 2 of inhaled PFP in mice (7.0 Tesla) and in healthy volunteers (3.0 Tesla). Results: Perfluoropropane T* 2 was sensitive to modulation of magnetic susceptibility difference between gas and water components of the lung, both in phantom models and in vivo. Negation of aqueous/gas phase magnetic susceptibility difference was achieved in lung-representative phantoms and in mice, resulting in a ~2 to 3× elevation in PFP T* 2 (3.7 to 8.5 ms and 0.7 to 2.6 ms, respectively). Human studies demonstrated a transient elevation of inhaled PFP T* 2 (1.50 to 1.64 ms) during passage of GBCA bolus through the lung circulation, demonstrating sensitivity to lung perfusion. Conclusion: We demonstrate indirect detection of a GBCA in the pulmonary microvasculature via changes to the T* 2 of gas phase PFP within directly adjacent alveoli. This approach holds potential for assessing alveolar perfusion by dynamic susceptibility contrast 19F-MRI of inhaled PFP, with concurrent assessment of lung ventilation properties, relevant to lung physiology and disease.
Author(s): Neal MA, Pippard BJ, Simpson AJ, Thelwall PE
Publication type: Article
Publication status: Published
Journal: Magnetic Resonance in Medicine
Pages: ePub ahead of Print
Online publication date: 29/08/2019
Acceptance date: 16/07/2019
Date deposited: 02/09/2019
ISSN (print): 0740-3194
ISSN (electronic): 1522-2594
Publisher: John Wiley and Sons Inc.
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