The ‘Double Dutch’ Doppler

A 42-year-old lady underwent a routine renal transplant ultrasound. She had IgA nephropathy and had received a first renal transplant from a deceased donor 2 years before. Her transplant function was stable and serum creatinine was found to be 200 μmol/l on tacrolimus monotherapy. On ultrasound, the renal transplant was 11 × 4 cm with mild parenchymal changes and no evidence of obstruction was found. Surprisingly, Doppler ultrasound of the segmental arteries showed two distinct and alternating waveforms (Figure 1). The patient was entirely asymptomatic. An electrocardiogram (ECG) showed sinus rhythm (Figure 2).