Kidney Week

Abstract: SA-PO309

Does Sodium Magnetic Resonance Imaging Help for Initiation of Incremental Dialysis?

Session Information

• Hemodialysis and Frequent Dialysis: Potpourri
  November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 701 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Lemoine, Sandrine, Universite de Lyon, Lyon, Auvergne-Rhône-Alpes , France

Sandrine Lemoine,

• Akbari, Alireza, Lawson Health Research Institute, London, Ontario, Canada

Alireza Akbari,

• Penny, Jarrin D., Lawson Health Research Institute, London, Ontario, Canada

Jarrin D. Penny,

• McIntyre, Christopher W., Lawson Health Research Institute, London, Ontario, Canada

Christopher W. McIntyre,

Background

Incremental HD (twice a week) can be proposed to some patients who had a significant residual renal function (RRF) when hemodialysis (HD) is initiated. However renal urea clearance is a very limited tool to assess the totality of crucial functions of the kidney, such as ability of the kidney to control salt and water excretion. We hypothesized that corticomedullary gradient (CMG) measurement with ²³NaMRI could provide a new tool to select HD patients potentially suitable for incremental dialysis.

Methods

We conducted a prospective observational study to better characterize CMG in HD patient with ²³NaMRI. We performed CMG measurment with ²³NaMRI in fasting patients. All MR experiments were carried out on a GE MR750 3T (GE Healthcare, WI). A custom-built two-loop (18cm in diameter) butterfly radiofrequency surface coil tuned for ²³Na frequency (33.786 MHz) was used to acquire renal ²³Na images. We compared CMG in healthy controls (n=15) and HD patients (n=10) with or without conventionally assessed RRF.

Results

For healthy controls, median (IQR) age was 50 (32-60), years old, 46% men, eGFR 103 (84-108) mL/min/1.73m², urinary osmolarity (osmU) 786 (587-938) osm/L. For HD patients, median(IQR) age was 50 (32-60) years old, 40 % men, urinary osmolarity (osmU) 313 (193-317) osm/L, 40% with residual renal function (RRF).
Corticomedullary gradient for controls (1,53 (1,47-1,61)), was significantly different to HD 1,32 (1,24-1,36) (p=0.001). There was a significant correlation between osmolarity and CMG (r=0.92, p<0.001). We were able to see a difference in salt repartition between HD patient with RRF and control. Anuric HD patients had lost medullary sodium entirely. Figure 1 shows difference in corticomedullary pictures (A) control; (B) HD patients with RRF; (C) HD patients with no RRF

Conclusion

We showed that is possible to assess corticomedullary gradient in HD patients. Additional study is justified to explore the ability to the ²³NaMRI to discriminate patients who might benefit best from an incremental dialysis approach.