Editing Breast imaging (section)

== '''MRI''' ==

** Technique
*** Generally done with gadolinium contrast - detect neovascularisation 
*** Elective MRI should be performed between menstruation and ovulation to account for variation in blood flow and epithelial proliferation
*** The contrast is not safe in pregnancy
** '''Indications'''
*** Identifying primary lesions

**** Identify the primary tumour in the breast for patients that present with unknown primary axillary metastases
**** Identify the primary tumour in Paget's disease of the nipple
**** Assessing size/extent of primary tumour, especially in younger women with dense breast tissue
**** Evaluating for the presence of multifocal or multicentric cancer
**** Evaluating invasive lobular cancer where BCS is planned

*** Assessing treatment response

**** Identify extent of residual disease after lumpectomy with positive margins
**** Assess treatment response after neoadjuvant chemotherapy

*** After implants

**** Assess implant rupture
**** Assess breast when silicone injections have been used

*** Screening

**** Can be done annually in women with high risk

** Sensitivity approaching 100% for invasive cancer, and up to 92% for DCIS
** Specificity not as good as mammogram or USS - high false-positive rate
** Always do mammogram at the same time - MRI may miss some malignancies that a mammogram would detect
** Generally not recommended for women with a lifetime risk of breast cancer <15% (higher risk of false positive)
** Need to wait 19 months after surgery to differentiate cancer and scar
** Can demonstrate axillary disease, but sensitivity not adequate to replace SLNB
** Good for assessing spinal metastases