gantry tilt re: CT brain

rekex · Joined: 05 Mar 2006 Posts: 19

i need some help.

i understand that when we do brain CT, we have to either ask patient to tilt their chin down or tilt the gantry so that we [i]avoid the orbits[/i].

i'm just not too sure as to WHY we want to avoid the orbits?
is it to reduce beam hardening artefact , or
to reduce dose to the lens of the eyes?

someone please clarify this for me.

thank you,
rekex

BMRTians · Joined: 27 Mar 2006 Posts: 3

It is to reduce the dose to the lens. It is a sensitive region to the radiation.
By doing this you can also reduce artifacts.
But with the new MDCT techniques nobody is worried about artifacts anymore. With thin sections added up together to form 5 mm or 10 mm slices you get the best spatial resolution in the posterior fossa.

Thanks

sachin
www.bmrtians.com