Cargando…
Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging
The bi-exponential intravoxel-incoherent-motion (IVIM) model for diffusion-weighted MRI (DWI) fails to account for differential T(2)s in the model compartments, resulting in overestimation of pseudodiffusion fraction f. An extended model, T2-IVIM, allows removal of the confounding echo-time (TE) dep...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
IOP Publishing
2016
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5952260/ https://www.ncbi.nlm.nih.gov/pubmed/27893459 http://dx.doi.org/10.1088/1361-6560/61/24/N667 |
_version_ | 1783323150681899008 |
---|---|
author | Jerome, N P d’Arcy, J A Feiweier, T Koh, D-M Leach, M O Collins, D J Orton, M R |
author_facet | Jerome, N P d’Arcy, J A Feiweier, T Koh, D-M Leach, M O Collins, D J Orton, M R |
author_sort | Jerome, N P |
collection | PubMed |
description | The bi-exponential intravoxel-incoherent-motion (IVIM) model for diffusion-weighted MRI (DWI) fails to account for differential T(2)s in the model compartments, resulting in overestimation of pseudodiffusion fraction f. An extended model, T2-IVIM, allows removal of the confounding echo-time (TE) dependence of f, and provides direct compartment T(2) estimates. Two consented healthy volunteer cohorts (n = 5, 6) underwent DWI comprising multiple TE/b-value combinations (Protocol 1: TE = 62–102 ms, b = 0–250 mm(−2)s, 30 combinations. Protocol 2: 8 b-values 0–800 mm(−2)s at TE = 62 ms, with 3 additional b-values 0–50 mm(−2)s at TE = 80, 100 ms; scanned twice). Data from liver ROIs were fitted with IVIM at individual TEs, and with the T2-IVIM model using all data. Repeat-measures coefficients of variation were assessed for Protocol 2. Conventional IVIM modelling at individual TEs (Protocol 1) demonstrated apparent f increasing with longer TE: 22.4 ± 7% (TE = 62 ms) to 30.7 ± 11% (TE = 102 ms); T2-IVIM model fitting accounted for all data variation. Fitting of Protocol 2 data using T2-IVIM yielded reduced f estimates (IVIM: 27.9 ± 6%, T2-IVIM: 18.3 ± 7%), as well as T(2) = 42.1 ± 7 ms, 77.6 ± 30 ms for true and pseudodiffusion compartments, respectively. A reduced Protocol 2 dataset yielded comparable results in a clinical time frame (11 min). The confounding dependence of IVIM f on TE can be accounted for using additional b/TE images and the extended T2-IVIM model. |
format | Online Article Text |
id | pubmed-5952260 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | IOP Publishing |
record_format | MEDLINE/PubMed |
spelling | pubmed-59522602018-05-18 Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging Jerome, N P d’Arcy, J A Feiweier, T Koh, D-M Leach, M O Collins, D J Orton, M R Phys Med Biol Note The bi-exponential intravoxel-incoherent-motion (IVIM) model for diffusion-weighted MRI (DWI) fails to account for differential T(2)s in the model compartments, resulting in overestimation of pseudodiffusion fraction f. An extended model, T2-IVIM, allows removal of the confounding echo-time (TE) dependence of f, and provides direct compartment T(2) estimates. Two consented healthy volunteer cohorts (n = 5, 6) underwent DWI comprising multiple TE/b-value combinations (Protocol 1: TE = 62–102 ms, b = 0–250 mm(−2)s, 30 combinations. Protocol 2: 8 b-values 0–800 mm(−2)s at TE = 62 ms, with 3 additional b-values 0–50 mm(−2)s at TE = 80, 100 ms; scanned twice). Data from liver ROIs were fitted with IVIM at individual TEs, and with the T2-IVIM model using all data. Repeat-measures coefficients of variation were assessed for Protocol 2. Conventional IVIM modelling at individual TEs (Protocol 1) demonstrated apparent f increasing with longer TE: 22.4 ± 7% (TE = 62 ms) to 30.7 ± 11% (TE = 102 ms); T2-IVIM model fitting accounted for all data variation. Fitting of Protocol 2 data using T2-IVIM yielded reduced f estimates (IVIM: 27.9 ± 6%, T2-IVIM: 18.3 ± 7%), as well as T(2) = 42.1 ± 7 ms, 77.6 ± 30 ms for true and pseudodiffusion compartments, respectively. A reduced Protocol 2 dataset yielded comparable results in a clinical time frame (11 min). The confounding dependence of IVIM f on TE can be accounted for using additional b/TE images and the extended T2-IVIM model. IOP Publishing 2016-12-21 2016-11-28 /pmc/articles/PMC5952260/ /pubmed/27893459 http://dx.doi.org/10.1088/1361-6560/61/24/N667 Text en © 2016 Institute of Physics and Engineering in Medicine http://creativecommons.org/licenses/by/3.0/ Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence (http://creativecommons.org/licenses/by/3.0) . Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
spellingShingle | Note Jerome, N P d’Arcy, J A Feiweier, T Koh, D-M Leach, M O Collins, D J Orton, M R Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
title | Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
title_full | Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
title_fullStr | Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
title_full_unstemmed | Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
title_short | Extended T2-IVIM model for correction of TE dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
title_sort | extended t2-ivim model for correction of te dependence of pseudo-diffusion volume fraction in clinical diffusion-weighted magnetic resonance imaging |
topic | Note |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5952260/ https://www.ncbi.nlm.nih.gov/pubmed/27893459 http://dx.doi.org/10.1088/1361-6560/61/24/N667 |
work_keys_str_mv | AT jeromenp extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging AT darcyja extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging AT feiweiert extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging AT kohdm extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging AT leachmo extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging AT collinsdj extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging AT ortonmr extendedt2ivimmodelforcorrectionoftedependenceofpseudodiffusionvolumefractioninclinicaldiffusionweightedmagneticresonanceimaging |