Three-dimensional gradient and spin-echo readout for time-encoded pseudo-continuous arterial spin labeling: influence of segmentation factor and flow compensation
| Autor: | Renata F. Leoni, André Monteiro Paschoal, Matthias J.P. van Osch, Bruno F. Pastorello |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Flow compensation flow compensation pCASL Signal-To-Noise Ratio Signal 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Imaging Three-Dimensional Technical Note Humans Radiology Nuclear Medicine and imaging Segmentation Technical Notes—Imaging Methodology FLUXO SANGUÍNEO Brain Arteries tSNR time‐encoded pCASL time-encoding Cerebral blood flow Cerebrovascular Circulation Spin echo Arterial blood Spin Labels 3D GRASE Perfusion 3d grase 030217 neurology & neurosurgery Biomedical engineering |
| Zdroj: | Magnetic Resonance in Medicine, 86(3), 1454-1462. WILEY Magnetic Resonance in Medicine Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Purpose: To monitor the complete passage of the labeled blood through the vascular tree into tissue and improve the quantification of ASL maps, we evaluated the effect of 3D gradient and spin -echo (GRASE) readout segments on temporal SNR (tSNR) and image blurriness for time -encoded pseudo -continuous arterial spin labeling and the effect of flow -compensation gradients on the presence of intravascular signal.Methods: Fifteen volunteers were scanned using time -encoded pCASL with 2D EPI and single -segment, two -segments, and three -segments 3D-GRASE readouts with first -order flow compensation (FC) gradients. Two -segments 3D-GRASE scans were acquired with 25%, 50%, 75%, and 100% of full first -order FC. Temporal SNR was assessed, and cerebral blood flow and arterial blood volume were quantified for all readout strategies.Results: For single -segment 3D GRASE, tSNR was comparable to 2D EPI for perfu sion signal but worse for the arterial signal. Two -segments and three -segments 3D GRASE resulted in higher tSNR than 2D EPI for perfusion and arterial signal. The arterial signal was not well visualized for 3D-GRASE data without. FC. Visualization of the intravascular signal at postlabeling delays of 660 ms and 1060 ms was restored with EC. Adequate visualization of the intravascular signal was achieved from 75% of FC gradient strength at a postlabeling delay of 660 ms. For a postlabeling delay of 1060 ms, full-FC gradients were the best option to depict intravascularConclusion: Segmented GRASE provided higher effective tSNR compared with 2D-EPI and single -segment GRASE. Flow compensation with GRASE readout should be carefully controlled when applying for time -encoded pCASL to visualize intravascular signal. |
| Databáze: | OpenAIRE |
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