What is the value of magnetic resonance venography in children before renal transplantation?

Radiological evaluation before renal transplantation includes imaging of vascular anatomy, as thrombosis, narrowing and anomalies of the inferior vena cava (IVC) and/or iliac veins (IV) can influence the surgical technique. Most cases only require investigation with Doppler vessel ultrasonography (US), with magnetic resonance venography (MRV) reserved to clarify US findings and investigate high-risk patients. The purpose of this study was to compare these modalities in evaluating IVC and IV and correlate imaging and operative findings of patients at RTx surgery. Twenty-nine children, 21 (72%) of whom had subsequent RTx surgery, were investigated over 5 years with correlation of US and MRV in 62% (18 of 29). Technically difficult US examinations needing MRV for clarification occurred in six (21%), and normal US with anatomical variations on MRV was seen in three (10%). The anatomical variations consisted of left-sided IVC, aberrant right common femoral vein and a left IV partly draining into the azygos and renal veins. US is an excellent screening tool for evaluating vascular anatomy patency in children. MRV infrequently contributes beneficial information, is difficult to justify as a screening tool, and due to the risks of gadolinium in uraemia, should only be used on an individual patient basis.