Positioning Tips for Veterinary CT

March 25, 2015

It is critical to produce clear and accurate diagnostic images. With veterinary CT, the position of your patient has a great deal to do with your image quality. Iso-centering will help you achieve the best results. Good iso-centering will result in consistent image quality and lower doses of radiation. Poor iso-centering increases surface radiation dose, which, in turn, increases noise, while decreasing the overall image quality. The patient needs to be centered precisely in the center of the scanning field for the calculated dose to be effective and minimize noise. This is Iso-centering.

What is an Iso-center?

An Iso-center is the central most point of the inner circle of the gantry -the intersection of the gantry axis of rotation.

When positioning a patient, it’s imperative that the body is not rotated or skewed in either direction. The sternum and the spine should be aligned on top of one another, as the head and rump should be straight, pointing in opposite directions. The anatomy that you're imaging should be iso-centered in the gantry. Please see examples below. Note how the patient is perfectly positioned with the head centered under the beam of the veterinary CT Scanner.

When the patient is asymmetrical or skewed, the anatomy on the CT, especially on the axial views, will be skewed and asymmetrical, thus making diagnostic evaluation challenging.

In summary, align your patient side to side and front to back (Symmetry), Center them in the gantry left to right and top to bottom (Iso-center) to achieve the highest quality exams.

Written by Danielle Dowden, Director of Education, Epica Medical Innovations.