beautypg.com

Scanning information, Scan parameters, Respiratory gating scanning information – Siemens EMOTION 16-Jun User Manual

Page 490

background image

490

Respiratory Gating

Scanning Information

The expected benefits in radiation treatment planning,
e.g. for lung and abdominal tumors are:

• Information about tumor motion in 3D coordinates

and over time

• More accurate tumor shape delineation and there-

fore a more precise RTP (radiation therapy planning)

• Potential for sparing of healthy tissue, minimization

of PTV (planned target volume) and less side effects

• Potential for dose acceleration and higher cure rate

To minimize motion artifacts, two requirements are
mandatory for a CT system:
– Fast gantry rotation to raise the temporal resolution

for artifact free images

– Prospective triggering of image acquisition in a

sequential mode or retrospective gating of image
reconstruction in a spiral mode based on the record-
ing of the respiratory curve in order to obtain images
during inspiration and expiration phases.

Scan Parameters

A respiratory gated lung spiral with cone correction
will be provided. To be able to work also with low
breathing rates, a fixed pitch factor of a min. of 0.1 is
needed. Slice widths and collimation are the same as
for cardio spiral.

In the Specials folder different scan protocols are pre-
defined for different breathing rates.