El-Diasty TA et al. (2005) Magnetic resonance imaging as a sole method for the morphological and functional evaluation of live kidney donors. BJU Int 96: 111–116

A safe, single alternative to the several separate procedures conventionally used to evaluate live kidney donors has been found by researchers at Mansoura University in Egypt. The new technique combines MRI of the kidney, ureter and renal blood vessels, and utilizes the contrast agent gadodiamide, which is injected into a vein and quickly distributes itself throughout the kidney, making the image clearer. This way, the anatomy, vasculature and glomerular filtration rate can be assessed simultaneously in order to check that both of the donor's kidneys are functioning well.

Examining a sample of 50 donors using MRI, and comparing the findings with those obtained after surgical removal of the kidneys, the researchers visualized the number of renal arteries and veins with ≥96% accuracy, correctly estimated renal size and shape, and successfully detected any abnormalities in the ureter and bladder. They also found no significant difference between the glomerular filtration rate estimated from MRI angiography and that from total 24 h creatinine clearance.

The technique does have one major drawback, however; renal stones cannot be detected by MRI alone, so it needs to be used in conjunction with ultrasonography.

Despite this additional step, El-Diasty et al. advocate MRI as being a more cost-effective examination than the traditional combination of catheter angiography and excretory urography and, unlike CT another potential single-evaluation method, it does not come with associated risks such as overexposure to ionizing radiation.