PhD Scientific Days 2025

Surgical Medicine

Comparison of Photon Counting Detector CT-based Renal Volumetry and Iodine Maps Versus Renal Scintigraphy for Predicting Remaining Kidney Function in Living Kidney Donor Candidates

Name of the presenter

Csákai-Szőke Péter

Institute/workplace of the presenter

Medical Imaging Centre

Authors

Dr. Csákai-Szőke Péter¹, Dr. Lénárd Zsuzsanna¹, Dr. Budai Bettina¹, Dakhlaoui Hana¹

1: Medical Imaging Centre

Text of the abstract

Aims:
Preoperative evaluation of living kidney donor candidates involves CT-based morphological and scintigraphy-based functional imaging to select kidneys for nephrectomy. The newly-introduced Photon Counting Detector CT (PCD-CT) offers highly accurate anatomical evaluation and iodine maps from contrast-enhanced phases. Our study aimed to investigate the correlation between renal volumetry and iodine uptake measured by PCD-CT versus split renal function (SRF) determined by dynamic renal scintigraphy, and their impact on kidney selection and postoperative kidney function.

Methods:
We included 88 consecutive potential kidney donor candidates who underwent multiphase PCD-CT scanning and 99mTc-DTPA-based dynamic renal scintigraphy. Cortical renal volume (CRV) and total parenchymal volume (TPV) were calculated based on cortical and total parenchymal segmentation of 176 kidneys. Average iodine concentration in these volumes was also determined. CT-based depth correction assessed split renal function. Among the 88 candidates, 40 (45%) underwent nephrectomy. Serum creatinine levels and eGFR (calculated with the CKD-EPI formula) were measured before and after nephrectomy.

Results:
We found a significant correlation between CRV and post-nephrectomy eGFR (r2=0.32, p=0.0059), as well as between average arterial phase iodine concentration and post-nephrectomy eGFR (r2=0.41, p=0.0014). In a multiple regression model, CRV and arterial iodine concentration were stronger predictors of post-nephrectomy renal function than cSRF (adjusted R-squares: 0.679 vs. 0.417, log-likelihood test p=0.0076).

Conclusion:
Future clinical use of automatic segmentation may eliminate the need for preoperative scintigraphy in living donor evaluations, reducing costs and patient radiation dose.

Funding:
No funding was received.