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Abstract: SA-PO092

Kidney Transplant Evaluation with Blood Oxygen Level Dependent (BOLD) and Diffusion-Weighted MRI: A Pilot Study

Session Information

Category: Transplantation

  • 1802 Transplantation: Clinical

Authors

  • Park, Meyeon, UCSF , San Francisco, California, United States
  • Gao, Ying, University of California, San Francisco, San Francisco, California, United States
  • Laszik, Zoltan G., University of California San Francisco, San Francisco, California, United States
  • Wang, Zhen Jane, UCSF Medical Center, San Francisco, California, United States
Background

Methods to identify etiologies of kidney allograft dysfunction in kidney transplant recipients (KTR) are generally limited to biopsy (bx). Blood oxygen level-dependent (BOLD) MRI can provide surrogate markers of tissue oxygen bioavailability. Diffusion-weighted (DW) intravoxel incoherent motion (IVIM) method can assess capillary perfusion and molecular diffusion, which may indicate tissue fibrosis. We explored these MRI methods as a non-invasive strategy to evaluate KTR undergoing bx.

Methods

We enrolled 14 KTR who underwent bx (12 protocol, 2 cause) at our center. Participants underwent research MRI scanning using BOLD and IVIM-DW protocols. Allograft bx were scored using Banff criteria by a single trained renal pathologist per clinical protocol. Individual Banff criteria were categorized as ordinal variables and corresponding MRI values were compared by the Kruskal-Wallis test. The mean difference estimate of the standardized MRI values between dichotomized abnormal and normal categories of Banff scores was calculated. Receiver operating characteristics (ROC) analysis was performed.

Results

Mean age was 50 (+/- 16); 9 (64%) were women. More severe grades of total inflammation (ti) were associated with lower BOLD R2* values (12.6 v. 13.8 v. 15, p=0.05); this may reflect lower oxygen consumption. Higher Banff scores for t, ptc, and i were associated with reduced capillary perfusion measured by IVIM-DW MRI (Fig). Area under curve (std error) for cortical interstitial fibrosis 0.8 (0.15) by BOLD and 0.95 (0.07) by DW.

Conclusion

BOLD and IVIM-DW MRI measures correlate with tissue pathology. IVIM-DW MRI may have more precision than BOLD to distinguish certain pathologic features on allograft bx. Functional MRI measures may be a useful screening tool to minimize kidney allograft bx.

Funding

  • NIDDK Support