Assessing Tissue Hydration Dynamics Based on Water/Fat Separated MRI

Markus Karlsson; Ainhoa Indurain; Thobias Romu; Patrik Tunon; Mårten Segelmark; Fredrik Uhlin; Anders Fernström; Olof Dahlqvist Leinhard

doi:10.1002/jmri.28581

Assessing Tissue Hydration Dynamics Based on Water/Fat Separated MRI

J Magn Reson Imaging. 2023 Aug;58(2):652-660. doi: 10.1002/jmri.28581. Epub 2023 Jan 2.

Authors

Markus Karlsson¹, Ainhoa Indurain^{2

3

4}, Thobias Romu^{1

5

6}, Patrik Tunon¹, Mårten Segelmark^{7

8}, Fredrik Uhlin^{2

3

9}, Anders Fernström^{2

3}, Olof Dahlqvist Leinhard^{1

2

6}

Affiliations

¹ AMRA Medical AB, Linköping, Sweden.
² Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
³ Department of Nephrology, Linköping University Hospital, Linköping, Sweden.
⁴ Department of Acute Internal Medicine and Geriatrics, Linköping University Hospital, Linköping, Sweden.
⁵ Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
⁶ Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden.
⁷ Department of Clinical Sciences, Lund University, Lund, Sweden.
⁸ Division of Nephrology Lund, Skåne University Hospital, Lund, Sweden.
⁹ Department of Health Technologies, Tallinn University of Technology, Tallinn, Estonia.

PMID: 36591977
DOI: 10.1002/jmri.28581

Abstract

Background: Optimal fluid status is an important issue in hemodialysis. Clinical evaluation of volume status and different diagnostic tools are used to determine hydration status in these patients. However, there is still no accurate method for this assessment.

Purpose: To propose and evaluate relative lean water signal (LWS_rel ) as a water-fat MRI-based tissue hydration measurement.

Study type: Prospective.

Population: A total of 16 healthy subjects (56 ± 6 years, 0 male) and 11 dialysis patients (60.3 ± 12.3 years, 9 male; dialysis time per week 15 ± 3.5 hours, dialysis duration 31.4 ± 27.9 months).

Field strength/sequence: A 3 T; 3D spoiled gradient echo.

Assessment: LWS_rel , a measurement of the water concentration of tissue, was estimated from fat-referenced MR images. Segmentations of total adipose tissue as well as thigh and calf muscles were used to measure LWS_rel and tissue volumes. LWS_rel was compared between healthy subjects and dialysis patients, the latter before and after dialysis. Bioimpedance-based body composition monitor over hydration (BCM OH) was also measured.

Statistical tests: T-tests were used to compare differences between the healthy subjects and dialysis patients, as well as changes between before and after dialysis. Pearson correlation was calculated between MRI and non-MRI biomarkers. A P value <0.05 was considered statistically significant.

Results: The LWS_rel in adipose tissue was significantly higher in the dialysis cohort compared with the healthy cohort (246.8% ± 60.0% vs. 100.0% ± 10.8%) and decreased significantly after dialysis (246.8 ± 60.0% vs. 233.8 ± 63.4%). Thigh and calf muscle volumes also significantly decreased by 3.78% ± 1.73% and 2.02% ± 2.50% after dialysis. There was a significant correlation between changes in adipose tissue LWS_rel and ultrafiltration volume (r = 87), as well as with BCM OH (r = 0.66).

Data conclusion: MRI-based LWS_rel and tissue volume measurements are sensitive to tissue hydration changes occurring during dialysis.

Evidence level: 2.

Technical efficacy: Stage 3.

Keywords: chemical shift imaging; dialysis; fat-water imaging; over hydration.

MeSH terms

Adipose Tissue* / diagnostic imaging
Body Composition / physiology
Body Water / diagnostic imaging
Body Water / physiology
Humans
Male
Prospective Studies
Water*

Substances

Water