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Magnetic Resonance Imaging Quantification of Pulmonary Perfusion using Calibrated Arterial Spin Labeling
Published on: May 30, 2011
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Walsh-ordered hadamard time-encoded pseudocontinuous ASL (WH pCASL).
Federico von Samson-Himmelstjerna1,2,3, Vince Istvan Madai2,3, Jan Sobesky2,3
1Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen, Germany.
Magnetic Resonance in Medicine
|December 31, 2015
Summary
New Hadamard encoding strategies for pseudocontinuous arterial spin labeling (H-pCASL) allow real-time access to perfusion-weighted images, even with incomplete data. This improves dynamic parameter adaptation and robustness in clinical applications.
Area of Science:
- Medical Imaging
- Biomedical Engineering
- Radiology
Background:
- Pseudocontinuous arterial spin labeling (pCASL) is a non-invasive MRI technique for measuring cerebral blood flow.
- Conventional H-pCASL methods can be time-consuming and sensitive to motion artifacts.
- Efficient acquisition and reconstruction of perfusion-weighted images are crucial for clinical utility.
Purpose of the Study:
- To introduce and evaluate a novel Walsh ordering of Hadamard encoding matrices for H-pCASL.
- To investigate an additional averaging strategy using a mirrored matrix to enhance image generation.
- To assess the feasibility of obtaining perfusion-weighted images from incomplete datasets during acquisition.
Main Methods:
- Hadamard encoding matrices were ordered using Walsh sequences.
- A mirrored Hadamard matrix was employed for averaging strategies.
- Perfusion-weighted images were generated from subsets of encoded data in healthy volunteers.
- Results were compared with conventional multi postlabeling-delay (PLD) pCASL measurements.
Main Results:
- Walsh-ordered Hadamard matrices enabled the generation of perfusion-weighted images from incomplete datasets.
- Early acquired image subsets yielded valid perfusion-weighted images.
- The mirrored matrix strategy increased the number of decodable images without increasing acquisition time.
- Generated images showed strong correlation with multi-PLD pCASL data.
Conclusions:
- The proposed H-pCASL method provides early access to perfusion-weighted images, facilitating dynamic parameter adjustments.
- This approach enhances robustness against artifacts, making it suitable for clinical settings.
- The technique offers potential for improved real-time monitoring and adaptation in neuroimaging.
