Using an aubergine as a phantom for practicing stereotactic guided core biopsy

Introduction

Practitioners learning how to perform stereotactic guided core biopsies need a nonhuman model to practice on. This presentation demonstrates a technique using contrast medium mixed with ink injected into an aubergine as a phantom to practice on, which has subsequently been used by the Jarvis Centre for teaching stereotaxis.

Equipment

(1) Black ink. (2) Any water-soluble contrast medium (preferably life expired). (3) A green needle to draw up ink and contrast medium and a 2 ml syringe. (4) A long orange needle to inject into the aubergine. (5) An aubergine. (6) A biopsy device and needle.

Technique

(1) Mix the ink and contrast medium. Inject the aubergine with a fine trail of black ink. Do not be heavy handed, you need very little – 0.5 ml at the most. (2) Turn the aubergine over 90° and place on the stereotactic table so that the line of ink is parallel to the table top. (3) Position as for a normal stereo and carry out the procedure as normal, including taking check pictures. (4) You will see immediately from the samples whether you have 'hit the spot' as you have black ink within the sample. It is possible to X-ray the sample to confirm this. (5) Do not send to pathology!

Pros

Simple cheap and easy. Do not have to practice on a patient but become proficient at using the equipment – no pain, lots of gain!

Cons

Not a perfect mimic of dots of calcification. Do not have the practice of adapting to patient movement. Risk of getting ink on hands and clothing.