Patients with large primary operable breast cancers are offered chemotherapy prior to surgery to shrink the tumour and enable breast conserving surgery. Conventional assessment of response to chemotherapy relies on a change in tumour size which does not always correlate with the change in amount of viable tumour. Newer techniques such as functional MRI, microbubble and optoacoustic ultrasound offer the potential to detect responses to chemotherapy by evaluating functional changes in tumour vascularity and oxygenation. Neither modality utilises ionising radiation.