As part of your breast assessment you may be asked to undergo an ultrasound scan. This is a painless and harmless procedure using a hand held ultrasonic probe and some water soluble gel that is applied to the skin. We sometimes use this to gather more information following mammography and it is our main method of imaging the armpit. If there are any biopsies that need to be taken, then we like to use this scan to guide our needle to the best location in real time. This is called an ultrasound image guided biopsy and allows us to be certain that we get the best sample to reach a diagnosis.