Abstract: FR-PO988

Effect of Hemodialysis on T2 Relaxation Times in Body Tissues

Session Information

Category: Bioengineering and Informatics

  • 101 Bioengineering and Informatics

Authors

  • Corapi, Kristin M., Massachusetts General Hospital, Boston, Massachusetts, United States
  • Colucci, Lina Avancini, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
  • Parada, Xavier F., Massachusetts General Hospital, Boston, Massachusetts, United States
  • Lin, Herbert Y., Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts, United States
  • Cima, Michael J., MIT, Cambridge, Massachusetts, United States
Background

Quantitative magnetic resonance (qMRI) can inform about the water content of different tissues. In this study we performed qMRI of the calf, pre and post-HD, to detect fluid changes in muscle and subcutaneous (SC) tissues.

Methods

Adult, male HD patients and healthy controls were enrolled. HD patients underwent qMRI before and after HD while controls underwent qMRI before and after 4 hours of bedrest. MRI scans were done on a 1.5T Siemens MRI Scanner using a knee coil. Quantitative T2 relaxation maps of the upper calf were generated using a spin echo sequences with 32 echoes, TR 3,300ms, TE 8ms, and 4 slices of 5mm thickness. Regions of interest (ROIs) enclosing SC tissue and muscle were manually drawn. Histograms of the T2 relaxation values in those ROIs were generated from the pre and post scans of all participants. The mean, median, and standard deviation of the T2 relaxation time distributions were calculated.

Results

Demographics are shown in table 1. HD patients have longer T2 relaxation times in both the muscle and SC tissue (figure 1a and 1b). We also observed a statistically significant (p=0.01) change in the T2 relaxation time for muscle, but not SC tissue (p=0.45), after treatment with hemodialysis (figure 1c and 1d).

Conclusion

Our results suggest that there is a larger change in relaxation time in muscle than in SC tissue during hemodialysis. This suggests more water movement from the muscle compartment than the SC tissue. Devices to better understand the kinetics of fluid shifts during HD may help alter prescriptions and mitigate symptoms.

Demographics of participants
 HD patients (n=4)Health Controls (n=5)
Age (years)56.8 (9.9)55.2 (5.9)
Weight (kg)84.7 (21.1)76.4 (14.5)
BMI (kg/m2)29.1 (7.0)25.9 (5.3)
Fluid removal (mL)2725 (1041)NA

data presented as mean (SD)

Funding

  • Private Foundation Support