When is this exam indicated?
It is particularly recommended in case of:
- congenital diseases: identification of the type of abnormality, its location as in the suspicion of agenesis, ectopia, "horseshoe" kidneys;
- cystic kidney disease: for the evaluation of residual functional mass, as in the case of infantile polycystic kidney and its monitoring;
- pyelonephritis: evaluation of scarring with loss of functional renal mass and monitoring of its progression;
- hydronephrosis: evaluation of residual functional renal mass in cases of kidneys functionally excluded by other instrumental investigations;
- trauma: evaluation and progress of post-traumatic outcomes.
How is it performed?
There is no preparation for the examination.
It involves the intravenous injection of a radiopharmaceutical (99TC-DMSA), 4 hours of waiting time before the acquisition of images, Gamma camera, equipped with a bed on which the patient must lie still. Images of the kidney are acquired in different projections for a duration of about 15 minutes. In particular cases, the examination can be continued up to 6 hours and can always be completed with SPECT tomographic acquisitions lasting 30 minutes. In pediatrics, it is possible to repeat the acquisition of some images, if a child has moved too much, but this does not require further radiation for a child.
The stay in the ward is variable from 4 to 6 hours.
No contraindications; drug interference: ACE inhibitors and mannitol may reduce cortical absorption of the radiocompound.