Kidney Week

Abstract: SA-OR033

Sodium Concentration in Tissues of Dialysis Patients

Session Information

• Fluids and Electrolytes: Clinical, Translational, and Acid-Base
  October 27, 2018 | Location: 23A, San Diego Convention Center
  Abstract Time: 04:54 PM - 05:06 PM

Category: Fluid and Electrolytes

• 902 Fluid and Electrolytes: Clinical

Authors

• Qirjazi, Elena, Western University, London, Ontario, Canada

Elena Qirjazi, MD



• Akbari, Alireza, Western University, London, Ontario, Canada

Alireza Akbari,

• Scholl, Timothy J., Western University, London, Ontario, Canada

Timothy J. Scholl,

• McIntyre, Christopher W., London Health Sciences Centre, London, Ontario, Canada

Christopher W. McIntyre,

Background

Dialysis patients are unable to fully remove sodium (²³Na). Thus, ²³Na is buffered in the skin, muscle and skeleton (osmotically inactive, but not biologically inert). We measured ²³Na content in these reservoirs using novel ²³Na MRI, in dialysis patients and healthy controls.

Methods

We undertook a pilot cross-sectional study of 26 subjects (10 controls and 16 dialysis - 9 peritoneal dialysis and 7 hemodialysis - patients). Subjects participated in a study session, which included collection of baseline information, bloodwork and a ²³Na MRI study using a multinuclear-capable 3.0T MRI (Discovery MR750, General Electric Healthcare). An axial proton T1-weighted fast-low-angle-shot sequence was acquired to delineate the anatomy; followed by a ²³Na MR image obtained with a custom-made lower-leg ²³Na coil and ²³Na-optimized pulse sequence (DA-3DPR). Maps of absolute tissue ²³Na concentration were generated using calibration vials of known ²³Na concentration included in the field-of-view. Four regions of interest were drawn, highlighting different tissues: 1) pre-tibial skin, 2) posterior leg skin (included because ²³Na distribution in skin was inhomogeneous), 3) soleus muscle, and 4) tibia.

Results

²³Na concentrations in the different tissues for both groups are shown in Fig. 1. Dialysis patients had statistically significant higher ²³Na levels in all four regions (p<0.05). Dialysis modality and gender did not have a significant effect.

Conclusion

Dialysis patients have significantly higher ²³Na level in their skin, muscle and bone compared to healthy controls.

Fig. 1: A: ²³Na concentration map of the lower leg and calibration vials for a dialysis patient. B: ²³Na concentration in different tissues in dialysis patients and controls. Error bars = standard deviation. * = statistically significant differences (p<0.05)