Kidney Week

Abstract: SA-PO1211

Towards Biopsy-Free Monitoring: Multimodal Imaging for Pediatric Kidney Transplant Recipients

Session Information

• Transplantation: Clinical - Complications, Pediatrics, and Multi-Organ Considerations
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 2002 Transplantation: Clinical

Authors

• Gnocchi, Giulia, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Giulia Gnocchi, MD

• Morales-Tisnes, Tatiana, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Tatiana Morales-Tisnes, MD

• Sultan, Laith R., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Laith R. Sultan, MD, MPH

• Otero, Hansel J., The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Hansel J. Otero, MD

• Viteri Baquerizo, Bernarda, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States

Bernarda Viteri Baquerizo, MD

Background

Kidney biopsy is invasive and not risk-free. We evaluated MRI and contrast enhanced ultrasound (CEUS) metrics association with allograft kidney pathology in pediatric kidney transplants.

Methods

In this IRB-approved prospective study, pediatric kidney transplants patients underwent MRI and CEUS within 24 hrs prior to biopsy. Healthy subjects served as MRI controls.
MRI included diffusion and morphological sequences (DTI, DWI, and T1 mapping). A radiologist segmented cortex and medulla for DTI and T1 mapping, and whole kidney (wk) for DWI. For CEUS, a 2-minute cine loop of the transplanted kidney was acquired after single contrast agent injection and 4 cortical regions of interest were selected per kidney.
MRI and CEUS quantitative parameters (Table 1) were obtained using dedicated software. Mixed-effects and generalized estimating equations models were used to evaluate associations between imaging parameters and 2017 Banff criteria (total inflammation (ti), chronic allograft damage index (CADI), and rejection). Analyses included cortical and medullary values, their difference (Δ) for DTI and T1, wk metrics for DWI, and cortical perfusion metrics for CEUS.

Results

Fifty kidneys (32 subjects; 14 F; median 15 yrs) were included for MRI: 28 controls and 22 transplants, 6 (27.3%) showing rejection. For CEUS, 47 studies were included from 32 subjects (8 F; median 15 yrs) as 12 subjects had 2 CEUS and 3 had 3. Transplants exhibited lower cortical FA (p<0.001), lower ΔDTI-ADC (p=0.011), and higher cortical T1 (p=0.009) compared with controls; cortical DTI-ADC and biexponential DWI-ADC were similar. Rejection was associated with lower cortical FA (p=0.035). Kidneys with ti had lower cortical FA (p=0.019), medullary FA (p=0.029), and cortical DTI-ADC (p=0.005). Cortical T1 was associated with CADI score (p=0.034). CEUS MTT was positively associated with higher CADI score, WoR showed a negative association. No CEUS metrics associated with ti or rejection.

Conclusion

MRI and CEUS are promising non-invasive tools for longitudinal monitoring of pediatric kidney transplants.

Table 1

Funding

• NIDDK Support