Related Experiment Video
Updated: Jan 24, 2026
Author Spotlight: Noninvasive Cerebral Blood Flow Determination in Human Functional Brain Region for Diagnosis of Neurological Disorders
Published on: May 31, 2024
Hyperintense signals in cerebral blood flow maps acquired with pseudo-continuous arterial spin labeling MRI in mice
Background And Purpose:
Pseudo-continuous arterial spin labeling (pCASL) MRI is a widely used, noninvasive, contrast-agent-free technique for measuring cerebral blood flow (CBF) and assessing vascular dysfunction across diverse clinical settings and murine disease models. In practice, arterial-transit artifacts that generate hyperintense signal in CBF maps warrant careful consideration. While these effects are well characterized in humans, they are less well understood in mice owing to the marked interspecies physiological differences.
Methods:
To address this knowledge gap, we systematically characterized pCASL hyperintense signal as a function of post-labeling delay (PLD) and crusher-gradient strength in mice. Numerical simulations were also performed to validate the experimental findings.
Results:
We found that hyperintense signals in mice extend to arteries, major veins, and ventricular structures (e.g., choroid plexus). Such a pattern was different from human pCASL images, where hyperintense signals are predominantly present in arteries. Statistical analyses supported a PLD of 500 ms as a pragmatic balance between detection sensitivity and suppression of vascular contamination. Additional experiments and numerical simulations showed that, within the tested range, stronger crusher gradients provided little extra vascular suppression-primarily because large vessel calibers relative to small voxels limit intravoxel phase dispersion. These findings refine the interpretation of murine pCASL signals and facilitate more accurate perfusion imaging in preclinical pathophysiological studies.
Insights
Pseudo-continuous arterial spin labeling (pCASL) MRI artifacts in mice differ from humans, affecting arteries, veins, and ventricles. Optimized post-labeling delay (PLD) and crusher gradients improve cerebral blood flow (CBF) imaging accuracy in preclinical studies.
Area of Science:
- Neuroimaging
- Medical Physics
- Preclinical Research
Background:
- Pseudo-continuous arterial spin labeling (pCASL) MRI is a noninvasive technique for measuring cerebral blood flow (CBF).
- Arterial-transit artifacts are common in pCASL, but less understood in mice compared to humans due to physiological differences.
- Accurate interpretation of pCASL in mice is crucial for preclinical studies of vascular dysfunction.
Purpose of the Study:
- To systematically characterize pCASL hyperintense signals in mice.
- To investigate the influence of post-labeling delay (PLD) and crusher-gradient strength on these artifacts.
- To provide guidance for optimizing pCASL imaging in murine models.
Main Methods:
- Systematic characterization of pCASL hyperintense signals in mice across varying PLDs and crusher-gradient strengths.
- Utilized numerical simulations to validate experimental findings.
- Statistical analyses to determine optimal imaging parameters.
Main Results:
- Hyperintense signals in murine pCASL extended to arteries, major veins, and ventricular structures, unlike in humans where they are mainly arterial.
- A PLD of 500 ms was found to be optimal for balancing sensitivity and vascular suppression.
- Stronger crusher gradients offered minimal additional vascular suppression in mice due to vessel size relative to voxel size.
Conclusions:
- Murine pCASL signal interpretation requires consideration of species-specific artifact patterns.
- A PLD of 500 ms is recommended for accurate murine pCASL imaging.
- Findings facilitate improved perfusion assessment in preclinical research using pCASL MRI.
Related Concept Videos
01:22Basic Continuous Time Signals
The unit step function, denoted u(t), is zero for negative time values and one for positive time values, exhibiting a discontinuity at t=0. This function often represents abrupt changes, such as the step voltage introduced when turning a car's...
01:11Sampling Continuous Time Signal
In the...
01:29Blood Flow
01:18Signal Flow Graphs
In a signal-flow graph, branches denote the system's transfer functions, while nodes represent the signals. The direction of signal flow is indicated by arrows, with the corresponding...
01:17Autoregulation of Blood Flow
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation....
01:08Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...