Dependency of R 2 and R 2 * relaxation on Gd-DTPA concentration in arterial blood: Influence of hematocrit and magnetic field strength.

Autor: van Dorth D; C. J. Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands., Venugopal K; Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands., Poot DHJ; Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands., Hirschler L; C. J. Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands., de Bresser J; Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands., Smits M; Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands., Hernandez-Tamames JA; Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands., Debacker CS; GHU Paris, Institut de Psychiatrie et Neurosciences, Hôpital Sainte-Anne, Paris, France., van Osch MJP; C. J. Gorter Center for High-Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
Jazyk: angličtina
Zdroj: NMR in biomedicine [NMR Biomed] 2022 May; Vol. 35 (5), pp. e4653. Date of Electronic Publication: 2021 Nov 23.
DOI: 10.1002/nbm.4653
Abstrakt: Dynamic susceptibility contrast (DSC) MRI is clinically used to measure brain perfusion by monitoring the dynamic passage of a bolus of contrast agent through the brain. For quantitative analysis of the DSC images, the arterial input function is required. It is known that the original assumption of a linear relation between the R 2 (*) relaxation and the arterial contrast agent concentration is invalid, although the exact relation is as of yet unknown. Studying this relation in vitro is time-consuming, because of the widespread variations in field strengths, MRI sequences, contrast agents, and physiological conditions. This study aims to simulate the R 2 (*) versus contrast concentration relation under varying physiological and technical conditions using an adapted version of an open-source simulation tool. The approach was validated with previously acquired data in human whole blood at 1.5 T by means of a gradient-echo sequence (proof-of-concept). Subsequently, the impact of hematocrit, field strength, and oxygen saturation on this relation was studied for both gradient-echo and spin-echo sequences. The results show that for both gradient-echo and spin-echo sequences, the relaxivity increases with hematocrit and field strength, while the hematocrit dependency was nonlinear for both types of MRI sequences. By contrast, oxygen saturation has only a minor effect. In conclusion, the simulation setup has proven to be an efficient method to rapidly calibrate and estimate the relation between R 2 (*) and gadolinium concentration in whole blood. This knowledge will be useful in future clinical work to more accurately retrieve quantitative information on brain perfusion.
(© 2021 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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