Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling
<p><strong>Purpose</strong></p> To extend and optimize a non-contrast MRI technique to obtain whole head 4D (time-resolved 3D) qualitative angiographic and perfusion images from a single scan. <p><strong>Methods</strong></p> 4D combined angiography an...
| Main Authors: | , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Wiley
2022
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| _version_ | 1797110104142643200 |
|---|---|
| author | Okell, TW Chiew, M |
| author_facet | Okell, TW Chiew, M |
| author_sort | Okell, TW |
| collection | OXFORD |
| description | <p><strong>Purpose</strong></p>
To extend and optimize a non-contrast MRI technique to obtain whole head 4D (time-resolved 3D) qualitative angiographic and perfusion images from a single scan.
<p><strong>Methods</strong></p>
4D combined angiography and perfusion using radial imaging and arterial spin labeling (CAPRIA) uses pseudocontinuous labeling with a 3D golden ratio (“koosh ball”) readout to continuously image the blood water as it travels through the arterial system and exchanges into the tissue. High spatial/temporal resolution angiograms and low spatial/temporal resolution perfusion images can be flexibly reconstructed from the same raw k-space data. Constant and variable flip angle (CFA and VFA, respectively) excitation schedules were optimized through simulations and tested in healthy volunteers. A conventional sensitivity encoding (SENSE) reconstruction was compared against a locally low rank (LLR) reconstruction, which leverages spatiotemporal correlations. Comparison was also made with time-matched time-of-flight angiography and multi-delay EPI perfusion images. Differences in image quality were assessed through split-scan repeatability.
<p><strong>Results</strong></p>
The optimized VFA schedule (2–9°) resulted in a significant (p < 0.001) improvement in image quality (up to 84% vs. CFA), particularly for the lower SNR perfusion images. The LLR reconstruction provided effective denoising without biasing the signal timecourses, significantly improving angiographic and perfusion image quality and repeatability (up to 143%, p < 0.001). 4D CAPRIA performed well compared with time-of-flight angiography and had better perfusion signal repeatability than the EPI-based approach (p < 0.001).
<p><strong>Conclusion</strong></p>
4D CAPRIA optimized using a VFA schedule and LLR reconstruction can yield high quality whole head 4D angiograms and perfusion images from a single scan. |
| first_indexed | 2024-03-07T07:50:24Z |
| format | Journal article |
| id | oxford-uuid:b3d5e359-d72f-484f-bfba-ff6e8028b641 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:50:24Z |
| publishDate | 2022 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:b3d5e359-d72f-484f-bfba-ff6e8028b6412023-07-10T12:05:19ZOptimization of 4D combined angiography and perfusion using radial imaging and arterial spin labelingJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b3d5e359-d72f-484f-bfba-ff6e8028b641EnglishSymplectic ElementsWiley2022Okell, TWChiew, M<p><strong>Purpose</strong></p> To extend and optimize a non-contrast MRI technique to obtain whole head 4D (time-resolved 3D) qualitative angiographic and perfusion images from a single scan. <p><strong>Methods</strong></p> 4D combined angiography and perfusion using radial imaging and arterial spin labeling (CAPRIA) uses pseudocontinuous labeling with a 3D golden ratio (“koosh ball”) readout to continuously image the blood water as it travels through the arterial system and exchanges into the tissue. High spatial/temporal resolution angiograms and low spatial/temporal resolution perfusion images can be flexibly reconstructed from the same raw k-space data. Constant and variable flip angle (CFA and VFA, respectively) excitation schedules were optimized through simulations and tested in healthy volunteers. A conventional sensitivity encoding (SENSE) reconstruction was compared against a locally low rank (LLR) reconstruction, which leverages spatiotemporal correlations. Comparison was also made with time-matched time-of-flight angiography and multi-delay EPI perfusion images. Differences in image quality were assessed through split-scan repeatability. <p><strong>Results</strong></p> The optimized VFA schedule (2–9°) resulted in a significant (p < 0.001) improvement in image quality (up to 84% vs. CFA), particularly for the lower SNR perfusion images. The LLR reconstruction provided effective denoising without biasing the signal timecourses, significantly improving angiographic and perfusion image quality and repeatability (up to 143%, p < 0.001). 4D CAPRIA performed well compared with time-of-flight angiography and had better perfusion signal repeatability than the EPI-based approach (p < 0.001). <p><strong>Conclusion</strong></p> 4D CAPRIA optimized using a VFA schedule and LLR reconstruction can yield high quality whole head 4D angiograms and perfusion images from a single scan. |
| spellingShingle | Okell, TW Chiew, M Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling |
| title | Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling |
| title_full | Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling |
| title_fullStr | Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling |
| title_full_unstemmed | Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling |
| title_short | Optimization of 4D combined angiography and perfusion using radial imaging and arterial spin labeling |
| title_sort | optimization of 4d combined angiography and perfusion using radial imaging and arterial spin labeling |
| work_keys_str_mv | AT okelltw optimizationof4dcombinedangiographyandperfusionusingradialimagingandarterialspinlabeling AT chiewm optimizationof4dcombinedangiographyandperfusionusingradialimagingandarterialspinlabeling |