What are the comparative risks of Gadolinium Contrast Medium versus Iodine Contrast Medium?

Reference: Acta Radiologica (2007)

	Iodinated Contrast	Gadolinium Contrast
The risk of a severe allergic reaction occurring	1:100,000 of people having iodinated contrast	Less than 1:170,000 of people having gadolinium contrast.
The risk of renal failure  if eGFR <30 ml/min):	20-40% will get contrast induced nephropathy (CIN) 5% will experience permanent decrease in renal function	No risk
The risk of NSF if eGFR < 15ml/min):	No risk	5%
The risk of a missed diagnosis if contrast medium is not used:	If CT scanning is inferior to MRI for the particular symptom or disease, the consequences of a missed diagnosis from the scanning procedure needs to be taken into consideration as a risk	If MRI is inferior to CT scanning for the particular symptom or disease, the consequences of a missed diagnosis from the scanning procedure needs to be taken into consideration as a risk.
The effect of a patient receiving dialysis soon after gadolinium contrast medium is given, to reduce the risk of developing NSF:
Haemodialysis	No effect	Reduces risk if performed fairly soon after the gadolinium contrast medium is given. Haemodialysis itself carries risks and unless the patient is already on haemodialysis the risks involved in starting haemodialysis probably outweigh the benefits.
Chronic ambulatory peritoneal dialysis (CAPD)		No significant effect at removing or reducing the amount of gadolinium in the circulation and tissues for many days.