To prepare for this question you'll need to do some research. Make phone calls, research websites or ask employees what type of equipment the company has. Besides talking about the equipment you specialized in, take this opportunity to briefly explain how, when and where you were trained on this equipment. Why did you specialize in the particular equipment?
"When I was trained by the military I had to opportunity to specialize as an Imaging Repair Specialist. In addition to MRI machines, I am also experienced in smaller laboratory equipment."
"Through my career as a biomedical technician, I've been lucky enough to work on almost all inpatient radiology equipment. I noticed in your job ad that you are looking for four years' experience working on x-ray and mammography machines. I have six years' experience in each."
"I just completed my specialty as an imaging repair specialist. I can work on equipment related to radiographic and fluoroscopic x-ray, ultrasound, nuclear imaging, and mammography.