The Living Kidney Donor: A Comprehensive Imaging Roadmap for Surgical Success

Abstract Renal transplantation is a favorable alternative to long-term dialysis in patients with end-stage renal disease and has witnessed remarkable success over the past few decades. Advances in surgical techniques, immunosuppressive therapies, and posttransplant care have made renal transplantation highly effective in prolonging survival and improving the quality of life of patients with end-stage renal disease. Compared with deceased donor transplantation, living donor transplantation offers advantages such as an expanded donor pool and elective scheduling, thereby minimizing unnecessary delays and facilitating the possibility of preemptive transplantation. Imaging plays a vital role in the preoperative evaluation of potential living kidney donors. This presentation aims to provide a comprehensive overview of imaging modalities, outlining their benefits, risks, advantages, and limitations. It also aims to discuss imaging findings and anatomical variations relevant to the selection of living renal donors, ultimately supporting surgical teams in identifying suitable donor candidates. A narrative review of the literature was conducted using PubMed, Scopus, and Google Scholar databases. Relevant literature on the imaging evaluation of living kidney donors was reviewed, with emphasis on vascular mapping, comparison of CT and MR angiography, essential components of radiology reporting, critical imaging findings that should be communicated to transplant surgeons, and their role in preoperative surgical planning. The reviewed literature supports ultrasound as an initial screening modality for the evaluation of potential living kidney donors, while renal volumetry and/or renal scintigraphy is valuable for the assessment of split renal function. Multidetector CT angiography remains the gold standard for living kidney donor evaluation, enabling accurate assessment of renal vascular anatomy, anatomical variants, parenchymal morphology, and the collecting system. MR angiography serves as an alternative imaging modality in selected patients with contraindications to iodinated contrast administration or radiation exposure. MR nephrography combined with angiography is emerging as a promising comprehensive imaging tool for simultaneous anatomical, vascular, and functional assessment in living kidney donor workup. Awareness of anatomical variants and detailed imaging reporting significantly influence the selection of the donor kidney and assist in planning the surgical approach.