Echo time dependence of biexponential and triexponential intravoxel incoherent motion parameters in the liver
(2022) In Magnetic Resonance in Medicine 87(2). p.859-871- Abstract
Purpose: Intravoxel incoherent motion (IVIM) studies are performed with different acquisition protocols. Comparing them requires knowledge of echo time (TE) dependencies. The TE-dependence of the biexponential perfusion fraction f is well-documented, unlike that of its triexponential counterparts f1 and f2 and the biexponential and triexponential pseudodiffusion coefficients D*, (Formula presented.), and (Formula presented.). The purpose was to investigate the TE-dependence of these parameters and to check whether the triexponential pseudodiffusion compartments are associated with arterial and venous blood. Methods: Fifteen healthy volunteers (19-58 y; mean: 24.7 y) underwent diffusion-weighted imaging... (More)
Purpose: Intravoxel incoherent motion (IVIM) studies are performed with different acquisition protocols. Comparing them requires knowledge of echo time (TE) dependencies. The TE-dependence of the biexponential perfusion fraction f is well-documented, unlike that of its triexponential counterparts f1 and f2 and the biexponential and triexponential pseudodiffusion coefficients D*, (Formula presented.), and (Formula presented.). The purpose was to investigate the TE-dependence of these parameters and to check whether the triexponential pseudodiffusion compartments are associated with arterial and venous blood. Methods: Fifteen healthy volunteers (19-58 y; mean: 24.7 y) underwent diffusion-weighted imaging of the abdomen with 24 b-values (0.2-800 s/mm2) at TEs of 45, 60, 75, and 90 ms. Regions of interest (ROIs) were manually drawn in the liver. One set of bi- and triexponential IVIM parameters per volunteer and TE was determined. The TE-dependence was assessed with the Kruskal-Wallis test. Results: TE-dependence was observed for f (P <.001), f1 (P =.001), and f2 (P <.001). Their median values at the four measured TEs were: f: 0.198/0.240/0.274/0.359, f1: 0.113/0.139/0.146/0.205, f2: 0.115/0.155/0.182/0.194. D, D*, (Formula presented.), and (Formula presented.) showed no significant TE-dependence. Their values were: diffusion coefficient D (10−4 mm2/s): 9.45/9.63/9.75/9.41, biexponential D* (10−2 mm2/s): 5.26/5.52/6.13/5.82, triexponential (Formula presented.) (10−2 mm2/s): 1.73/2.91/2.25/2.51, triexponential (Formula presented.) (mm2/s): 0.478/1.385/0.616/0.846. Conclusion: f1 and f2 show similar TE-dependence as f, ie, increase with rising TE; an effect that must be accounted for when comparing different studies. The diffusion and pseudodiffusion coefficients might be compared without TE correction. Because of the similar TE-dependence of f1 and f2, the triexponential pseudodiffusion compartments are most probably not associated to venous and arterial blood.
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- author
- Führes, Tobit ; Riexinger, Andreas Julian ; Loh, Martin ; Martin, Jan LU ; Wetscherek, Andreas ; Kuder, Tristan Anselm ; Uder, Michael ; Hensel, Bernhard and Laun, Frederik Bernd
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- diffusion, echo time, IVIM, liver, perfusion
- in
- Magnetic Resonance in Medicine
- volume
- 87
- issue
- 2
- pages
- 859 - 871
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:85113686773
- pmid:34453445
- ISSN
- 0740-3194
- DOI
- 10.1002/mrm.28996
- language
- English
- LU publication?
- yes
- id
- 41e50dc1-e227-4aec-aeb3-e79a1ced95c1
- date added to LUP
- 2021-09-28 16:42:05
- date last changed
- 2024-06-15 17:08:17
@article{41e50dc1-e227-4aec-aeb3-e79a1ced95c1,
abstract = {{<p>Purpose: Intravoxel incoherent motion (IVIM) studies are performed with different acquisition protocols. Comparing them requires knowledge of echo time (TE) dependencies. The TE-dependence of the biexponential perfusion fraction f is well-documented, unlike that of its triexponential counterparts f<sub>1</sub> and f<sub>2</sub> and the biexponential and triexponential pseudodiffusion coefficients D<sup>*</sup>, (Formula presented.), and (Formula presented.). The purpose was to investigate the TE-dependence of these parameters and to check whether the triexponential pseudodiffusion compartments are associated with arterial and venous blood. Methods: Fifteen healthy volunteers (19-58 y; mean: 24.7 y) underwent diffusion-weighted imaging of the abdomen with 24 b-values (0.2-800 s/mm<sup>2</sup>) at TEs of 45, 60, 75, and 90 ms. Regions of interest (ROIs) were manually drawn in the liver. One set of bi- and triexponential IVIM parameters per volunteer and TE was determined. The TE-dependence was assessed with the Kruskal-Wallis test. Results: TE-dependence was observed for f (P <.001), f<sub>1</sub> (P =.001), and f<sub>2</sub> (P <.001). Their median values at the four measured TEs were: f: 0.198/0.240/0.274/0.359, f<sub>1</sub>: 0.113/0.139/0.146/0.205, f<sub>2</sub>: 0.115/0.155/0.182/0.194. D, D<sup>*</sup>, (Formula presented.), and (Formula presented.) showed no significant TE-dependence. Their values were: diffusion coefficient D (10<sup>−4</sup> mm<sup>2</sup>/s): 9.45/9.63/9.75/9.41, biexponential D<sup>*</sup> (10<sup>−2</sup> mm<sup>2</sup>/s): 5.26/5.52/6.13/5.82, triexponential (Formula presented.) (10<sup>−2</sup> mm<sup>2</sup>/s): 1.73/2.91/2.25/2.51, triexponential (Formula presented.) (mm<sup>2</sup>/s): 0.478/1.385/0.616/0.846. Conclusion: f<sub>1</sub> and f<sub>2</sub> show similar TE-dependence as f, ie, increase with rising TE; an effect that must be accounted for when comparing different studies. The diffusion and pseudodiffusion coefficients might be compared without TE correction. Because of the similar TE-dependence of f<sub>1</sub> and f<sub>2</sub>, the triexponential pseudodiffusion compartments are most probably not associated to venous and arterial blood.</p>}},
author = {{Führes, Tobit and Riexinger, Andreas Julian and Loh, Martin and Martin, Jan and Wetscherek, Andreas and Kuder, Tristan Anselm and Uder, Michael and Hensel, Bernhard and Laun, Frederik Bernd}},
issn = {{0740-3194}},
keywords = {{diffusion; echo time; IVIM; liver; perfusion}},
language = {{eng}},
number = {{2}},
pages = {{859--871}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Magnetic Resonance in Medicine}},
title = {{Echo time dependence of biexponential and triexponential intravoxel incoherent motion parameters in the liver}},
url = {{http://dx.doi.org/10.1002/mrm.28996}},
doi = {{10.1002/mrm.28996}},
volume = {{87}},
year = {{2022}},
}