Question

Discuss the radiological work-up of a prospective renal donor.

Hint:

Radiological imaging should be thorough to ensure the safety of the donor. The most important assessments include ultrasound, CTA, and GFR evaluation.

Answer 1

The radiological work-up of a prospective renal donor is crucial to ensure the safety of both the donor and the recipient. It helps evaluate the donor's renal anatomy, function, and vascular structures, as well as detect any contraindications to donation.
Step 1: Imaging Studies to Evaluate Kidney Anatomy.
1. Ultrasound: A renal ultrasound is often the first imaging study performed to assess the kidney size, shape, and parenchymal quality. It can detect any anatomical abnormalities like hydronephrosis, cysts, or masses.
2. CT Angiography (CT: CTA is performed to evaluate the renal vasculature. It provides detailed images of the renal arteries and veins, helping assess for any vascular anomalies (e.g., accessory renal arteries, renal artery stenosis, or aneurysms).
3. MRI/MRA: Magnetic resonance imaging (MRI) or magnetic resonance angiography (MR can be used to further assess renal vasculature, particularly in patients with contraindications to contrast agents or for more detailed vascular mapping.
4. CT Scan: A contrast-enhanced CT scan is performed to assess the kidney’s blood supply and drainage system. It provides a clear image of the renal arteries and veins, aiding in the selection of the kidney for donation.
Step 2: Renal Function Tests.
1. Glomerular Filtration Rate (GFR): Preoperative assessment of kidney function is done through measuring the GFR to ensure that both kidneys are functioning well and to assess the risk of donating a kidney. A GFR of at least 80-90 mL/min is generally considered acceptable for donation.
2. Urine Tests: Urinalysis, urine protein levels, and other tests help rule out any signs of kidney disease, including proteinuria or hematuria, which could indicate underlying kidney damage.
Step 3: Assessing for Contraindications.
Any findings that suggest underlying kidney disease (e.g., renal cysts, tumors, or significant vascular abnormalities) or risk factors that may contraindicate donation (e.g., hypertension, diabetes, or a history of kidney disease) should be carefully evaluated.