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Addressing fatty tissue in quantitative susceptibility mapping of human knee cartilage

Säll, Cornelia LU ; Lind, Emelie LU orcid ; Einarsson, Emma LU orcid ; Turkiewicz, Aleksandra LU ; Englund, Martin LU orcid and Peterson, Pernilla LU (2025) In Magnetic Resonance Materials in Physics, Biology and Medicine 38(6). p.921-931
Abstract

Objective: To evaluate the effects of excluding fatty tissue in QSM of human knee cartilage. Materials and methods: Gradient echo images from 18 knee-healthy volunteers were acquired, from which chemical shift corrected field perturbation maps were calculated. Based on these, QSM maps were reconstructed using morphology enabled dipole inversion and one of three masking alternatives: (1) excluding no tissue, (2) excluding bone marrow, and (3) excluding all fatty tissues. The slope of a linear regression [ppm/%] between susceptibility values and the relative distance from the bone surfaces was used as a measurement of contrast between cartilage layers. The average differences in slopes between methods are reported with 95% confidence... (More)

Objective: To evaluate the effects of excluding fatty tissue in QSM of human knee cartilage. Materials and methods: Gradient echo images from 18 knee-healthy volunteers were acquired, from which chemical shift corrected field perturbation maps were calculated. Based on these, QSM maps were reconstructed using morphology enabled dipole inversion and one of three masking alternatives: (1) excluding no tissue, (2) excluding bone marrow, and (3) excluding all fatty tissues. The slope of a linear regression [ppm/%] between susceptibility values and the relative distance from the bone surfaces was used as a measurement of contrast between cartilage layers. The average differences in slopes between methods are reported with 95% confidence intervals. Results: The expected susceptibility differences between cartilage layers from literature were observed for all tested reconstruction techniques. However, smaller slopes (average difference (confidence interval)) were detected when either all fatty tissue (− 0.090 (− 0.121, − 0.059) ppm/%) or bone marrow (− 0.088 (− 0.121, − 0.055) ppm/%) was excluded from reconstruction. Discussion: All tested methods result in adequate image quality in QSM of knee cartilage. However, exclusion of fatty tissue decreased the susceptibility contrast between cartilage layers. Assuming that phase contributions from chemical shift are addressed, inclusion of fatty tissue may be preferable.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cartilage, Fatty tissue, Osteoarthritis, QSM
in
Magnetic Resonance Materials in Physics, Biology and Medicine
volume
38
issue
6
pages
11 pages
publisher
Springer
external identifiers
  • scopus:105011384884
  • pmid:40705177
ISSN
0968-5243
DOI
10.1007/s10334-025-01280-0
language
English
LU publication?
yes
additional info
Publisher Copyright: © The Author(s) 2025.
id
39af60b1-08c3-421a-9c42-a8d34b07e5fe
date added to LUP
2025-12-19 13:14:57
date last changed
2025-12-20 03:24:16
@article{39af60b1-08c3-421a-9c42-a8d34b07e5fe,
  abstract     = {{<p>Objective: To evaluate the effects of excluding fatty tissue in QSM of human knee cartilage. Materials and methods: Gradient echo images from 18 knee-healthy volunteers were acquired, from which chemical shift corrected field perturbation maps were calculated. Based on these, QSM maps were reconstructed using morphology enabled dipole inversion and one of three masking alternatives: (1) excluding no tissue, (2) excluding bone marrow, and (3) excluding all fatty tissues. The slope of a linear regression [ppm/%] between susceptibility values and the relative distance from the bone surfaces was used as a measurement of contrast between cartilage layers. The average differences in slopes between methods are reported with 95% confidence intervals. Results: The expected susceptibility differences between cartilage layers from literature were observed for all tested reconstruction techniques. However, smaller slopes (average difference (confidence interval)) were detected when either all fatty tissue (− 0.090 (− 0.121, − 0.059) ppm/%) or bone marrow (− 0.088 (− 0.121, − 0.055) ppm/%) was excluded from reconstruction. Discussion: All tested methods result in adequate image quality in QSM of knee cartilage. However, exclusion of fatty tissue decreased the susceptibility contrast between cartilage layers. Assuming that phase contributions from chemical shift are addressed, inclusion of fatty tissue may be preferable.</p>}},
  author       = {{Säll, Cornelia and Lind, Emelie and Einarsson, Emma and Turkiewicz, Aleksandra and Englund, Martin and Peterson, Pernilla}},
  issn         = {{0968-5243}},
  keywords     = {{Cartilage; Fatty tissue; Osteoarthritis; QSM}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{921--931}},
  publisher    = {{Springer}},
  series       = {{Magnetic Resonance Materials in Physics, Biology and Medicine}},
  title        = {{Addressing fatty tissue in quantitative susceptibility mapping of human knee cartilage}},
  url          = {{http://dx.doi.org/10.1007/s10334-025-01280-0}},
  doi          = {{10.1007/s10334-025-01280-0}},
  volume       = {{38}},
  year         = {{2025}},
}