Dimercaptosuccinic acid imaging

Static renal imaging provides morphological information on each kidney. It is most commonly performed using 99m technetium labelled dimercaptosuccinic acid which becomes fixed in the proximal renal tubular cells. DMSA imaging enables assessment of:

• size and position of the kidneys
• differential function - expressed as a percentage of the total function. The upper limit of normal is 5% either side of 50%. A kidney functioning at 15% of more is still useful; one whose function is less than 7% is not.
• parenchymal defects - scars, cysts, tumours, ischaemic areas in renal hypertension
• morphological abnormalities such as duplex and horseshoe kidney

Imaging should not be performed too soon after a UTI as it will identify areas of transient ischaemia. Postponement for about three months is recommended.