Monitoring of renal function using 99mTc-DMSA and 99mTc-DTPA scintigraphy in patients with spinal cord injury

The aim of this study was to assess the degree of alterations of renal function by using 99m-technetium dimercaptosuccinic acid ((99m)Tc-DMSA) and 99m-technetium diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) scintigraphy in spinal cord injury (SCI) patients.

Twenty-two consecutive SCI (15 paraplegic and 7 tetraplegic) patients (mean age: 49.1±13.4 years) who had no urinary symptoms participated in this prospective study. The mean duration of injury was 45.6±48.8 months before. Sixteen patients had at least one urinary tract infection history. Renal cortical scintigraphy with (99m)Tc-DMSA, radionuclide renography with (99m)Tc-DTPA and renal ultrasound were performed within 2-week period.

Four (18%) patients had serious pathology on their kidneys such as unilateral or bilateral parenchymal scarring and increased background uptake in their renal cortical scintigraphy with (99m)Tc-DMSA. Two of them had grade 3-4 pelvicaliceal ectasia on ultrasound. Additionally, 2 of 18 remaining patients had grade 2 pelvicaliceal ectasia on ultrasound. Sixteen (73%) patients had markedly delayed or delayed and decreased functions of one or both of kidneys on radionuclide renography. However, only four patients had grade 2-4 pelvicaliceal ectasia and none of them had a finding of loosening of renal parenchyma.

Combined use of renal cortical scintigraphy and radionuclide renography appears to be contributive to renal ultrasound in the long-term follow-up of patients with SCI. Patients with abnormal findings should be closely followed, and early therapeutic interventions may enable lower morbidity and mortality rates in these patients.