Meetings » 10th CTUG Meeting » Abstracts

A Simple anthropomorphic phantom used to demonstrate effectiveness of CT dose Modulation functions

Lynn Bateman

North Wales Medical Physics,
North Wales NHS Trust


All CT scanner manufacturers now offer some degree of automatic exposure control with new scanners. Unsurprisingly, they all work differently. Ensuring the system is working as designed, and comparing different settings is not possible using the traditional phantoms that have been used in CT scanner QA. This is because these phantoms have a circular cross section and so do not present the scanner with the attenuation differences it requires to modulate the tube current. This problem was addressed in North Wales by the design and manufacture of a new simple phantom. It is considered that the major anatomical contributors to the attenuation variation are posed by the change from small near circular neck to the large elliptical shoulders, then onto the low attenuation chest cavity followed by the soft tissue filled abdomen.

The phantom consists of a water filled anatomical shell from chin to lower abdomen, with the major features of air filled lungs and spine to complement the anatomical variations.

This presentation shows how the phantom works with different manufacturers systems and how it has been used to help optimise clinical practice.

Click the link for a pdf of the presentation: view pdf version of presentation

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