Current guidance states that MRI should only be used to investigate anomalies revealed on mammography.
But under revised NICE guidelines, which are open for consultation until mid-June, women aged 30-49 years with known BRCA1 or BRCA2 mutations or a high risk of carrying BRCA1 mutations, should be referred for routine MRI scans instead of, or in addition to, mammography.
Women under 30 at very high breast cancer risk, such as those carrying the TP53 mutation, should also be referred for MRI.
However, women from families with a history of BRCA2 mutations would not be eligible for the scan.
The turnaround follows a study which showed MRI identified four times as many true cases of breast cancer as mammography, and only a tenth the number of false negatives in women with the BRCA1 mutation.
Dr James Mackay, a consultant genetic oncologist at University College London, said the rules on who would become eligible for MRI were 'complex' and called for GPs to be given guidance on eligibility for breast MRI.
He added that the decision to exclude patients with a family history of BRCA2 mutations from MRI screening would lead to patient upset.
'Certain people won't be given access because of the rules as laid out here. This will cause tremendous upset if it is implemented in the form it has been put forward in. If people are going to be upset, they need to speak up now,' he said.
Dr Robert Bailey, a GP in Peterborough with an interest in breast cancer, said it was important that GPs be aware of those patients at increased risk of developing familial breast cancer.
'We have to identify those women who may be at increased risk of breast cancer,' he said.
He added that although MRI screening would benefit younger women with a high risk of familial breast cancer, it would further overburden MRI services.
Increased demand would be put on limited digital mammography services under the guidelines. The final guideline is due to be published in September.
- NICE draft guidelines; Live links at GPonline.com.