Sinusoidal CO2 respiratory challenge for concurrent perfusion and cerebrovascular reactivity MRI

Chau Vu; Botian Xu; Clio González-Zacarías; Jian Shen; Koen P A Baas; Soyoung Choi; Aart J Nederveen; John C Wood

doi:10.3389/fphys.2023.1102983

Sinusoidal CO₂ respiratory challenge for concurrent perfusion and cerebrovascular reactivity MRI

Front Physiol. 2023 Feb 9:14:1102983. doi: 10.3389/fphys.2023.1102983. eCollection 2023.

Authors

Chau Vu^{1

2}, Botian Xu^{1

2}, Clio González-Zacarías^{2

3

4}, Jian Shen^{1

2}, Koen P A Baas⁵, Soyoung Choi^{2

3

4}, Aart J Nederveen⁵, John C Wood^{1

2}

Affiliations

¹ Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States.
² Division of Cardiology, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA, United States.
³ Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States.
⁴ Signal and Image Processing Institute, University of Southern California, Los Angeles, CA, United States.
⁵ Department of Radiology and Nuclear Medicine, Amsterdam UMC, Location AMC, Amsterdam, Netherlands.

Abstract

Introduction: Deoxygenation-based dynamic susceptibility contrast (dDSC) has previously leveraged respiratory challenges to modulate blood oxygen content as an endogenous source of contrast alternative to gadolinium injection in perfusion-weighted MRI. This work proposed the use of sinusoidal modulation of end-tidal CO₂ pressures (SineCO ₂ ), which has previously been used to measure cerebrovascular reactivity, to induce susceptibility-weighted gradient-echo signal loss to measure brain perfusion. Methods: SineCO ₂ was performed in 10 healthy volunteers (age 37 ± 11, 60% female), and tracer kinetics model was applied in the frequency domain to calculate cerebral blood flow, cerebral blood volume, mean transit time, and temporal delay. These perfusion estimates were compared against reference techniques, including gadolinium-based DSC, arterial spin labeling, and phase contrast. Results: Our results showed regional agreement between SineCO ₂ and the clinical comparators. SineCO ₂ was able to generate robust CVR maps in conjunction to baseline perfusion estimates. Discussion: Overall, this work demonstrated feasibility of using sinusoidal CO₂ respiratory paradigm to simultaneously acquire both cerebral perfusion and cerebrovascular reactivity maps in one imaging sequence.

Keywords: brain perfusion; carbon dioxide challenge; cerebrovascular reactivity (CVR); deoxygenation; dynamic susceptibility contrast (DSC); respiratory challenges.

Grants and funding

UL1 TR000130/TR/NCATS NIH HHS/United States