nephrogram phase
Last reviewed 01/2018
The nephrogram is that part of the IVU during which contrast is in the glomeruli and proximal tubules. It occurs 1-3 minutes after injection.
It enables the assessment of:
- presence - are there bilateral functioning kidneys
- size - normal range is approximately the height of three vertebral bodies. Bilateral, enlarged kidneys suggest polycystic disease, acute pyelonephritis or glomerulonephritis. Bilateral, shrunken kidneys imply chronic disease.
- shape - cysts and tumours may cause distortion. The two are often indistinguishable, however, tumours opacify to a variable extent, and may show a characteristic "vascular blush."
- orientation - disorientation may be intrinsic, for example, a horseshoe kidney, or extrinsic i.e. the effects of pressure from other organs.