scholarly journals Cerebral perfusion imaging: Hypoxia-induced deoxyhemoglobin or gadolinium?

2021 ◽  
Author(s):  
Ece Su Sayin ◽  
Jacob Schulman ◽  
Julien Poublanc ◽  
Harrison Levine ◽  
Lakshmikumar Venkatraghavan ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Dynamic Susceptibility ◽  
Resonance Imaging ◽  
Dynamic Susceptibility Contrast ◽  
Initial Comparison ◽  
Susceptibility Contrast

Assessment of resting cerebrovascular perfusion measures (mean transit time, cerebral blood flow and cerebral blood volume) with magnetic resonance imaging currently requires the intravascular injection of the dynamic susceptibility contrast agent gadolinium. An initial comparison between hypoxia-induced deoxyhemoglobin and gadolinium was made for these measures in six healthy participants. A bolus of deoxyhemoglobin is generated in the lung via transient hypoxia induced by an available computer-controlled gas blender technology employing sequential gas delivery (RespirAct). We hypothesised and confirmed perfusion measures from both susceptibility contrast agents would yield similar spatial patterns of cerebrovascular perfusion measures. We conclude that hypoxia-induced deoxyhemoglobin, an endogenously, non-invasively generated, non-allergenic, non-toxic, recyclable, environmentally innocuous molecule, may be suitable to become the first new magnetic resonance imaging susceptibility contrast agent introduction since gadolinium.

scholarly journals Anisotropic cerebral vascular architecture causes orientation dependency in cerebral blood flow and volume measured with dynamic susceptibility contrast magnetic resonance imaging

2016 ◽  
Vol 37 (3) ◽  
pp. 1108-1119 ◽  
Author(s):  
Enedino Hernández-Torres ◽  
Nora Kassner ◽  
Nils Daniel Forkert ◽  
Luxi Wei ◽  
Vanessa Wiggermann ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Dynamic Susceptibility ◽  
Resonance Imaging ◽  
Dynamic Susceptibility Contrast ◽  
Contrast Magnetic Resonance Imaging ◽  
Contrast Magnetic Resonance ◽  
Tissue Orientation ◽  
Susceptibility Contrast

Measurements of cerebral perfusion using dynamic susceptibility contrast magnetic resonance imaging rely on the assumption of isotropic vascular architecture. However, a considerable fraction of vessels runs in parallel with white matter tracts. Here, we investigate the effects of tissue orientation on dynamic susceptibility contrast magnetic resonance imaging. Tissue orientation was measured using diffusion tensor imaging and dynamic susceptibility contrast was performed with gradient echo planar imaging. Perfusion parameters and the raw dynamic susceptibility contrast signals were correlated with tissue orientation. Additionally, numerical simulations were performed for a range of vascular volumes of both the isotropic vascular bed and anisotropic vessel components, as well as for a range of contrast agent concentrations. The effect of the contrast agent was much larger in white matter tissue perpendicular to the main magnetic field compared to white matter parallel to the main magnetic field. In addition, cerebral blood flow and cerebral blood volume were affected in the same way with angle-dependent variations of up to 130%. Mean transit time and time to maximum of the residual curve exhibited weak orientation dependency of 10%. Numerical simulations agreed with the measured data, showing that one-third of the white matter vascular volume is comprised of vessels running in parallel with the fibre tracts.

Attempts to improve absolute quantification of cerebral blood flow in dynamic susceptibility contrast magnetic resonance imaging: a simplified T1-weighted steady-state cerebral blood volume approach

2007 ◽  
Vol 48 (5) ◽  
pp. 550-556 ◽  
Author(s):  
R. Wirestam ◽  
L. Knutsson ◽  
J. Risberg ◽  
S. Börjesson ◽  
E.-M. Larsson ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Water Exchange ◽  
Cerebral Blood Volume ◽  
Dynamic Susceptibility ◽  
Resonance Imaging ◽  
Dynamic Susceptibility Contrast ◽  
Dsc Mri ◽  
Contrast Magnetic Resonance ◽  
Susceptibility Contrast

Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. Material and Methods: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = K×CBF(DSC). Results: Average whole-brain SPECT CBF was 40.1±6.9 ml/min·100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2±13.8 ml/min·100 g. After correction with the calibration factor, a CBF(ss) of 42.7±14.0 ml/min·100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality ( R = 0.52). Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.

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