Introduction; Overview - Philips CARDIOMD Service Manual

12.1 Introduction

Attenuation correction is a method allowing the emission images acquired during SPECT
acquisitions to be corrected for attenuation within the patient. The purpose of attenuation
correction is to compensate for varying attenuation of gamma rays in the body.
The Attenuation Correction option is intended to provide the user with a means of measuring the
attenuation of gamma rays within the patient's body when using the CardioMD System for
SPECT studies, and to map the measured attenuation into images that can be used to correct
emission images for the attenuation.

12.2 Overview

The CardioMD AC Option consists of two transmission scanners that mount onto the end piece of
each CardioMD detector. The two scanners are identical, with the exception that they contain
different software in the motion controller controlling the movement of the line source. For this
reason, the two scanners are mechanically coded to prevent them being swapped by mistake.
CAUTION
Each of the transmission scanners consists of the following parts:
•
AC option bracket
•
Line source compartment
•
Line source housing with shutter
•
Gd-153 line source.
Figure 12.1 shows the AC Option transmission scanner mounted on one of the detectors. The line
source housing with the Gd-153 line source is located inside the line source compartment (see
Figure 12.3, page 12-6).
1MAN0158-H11 04-2005 CSIP Level 1
Caution. It is possible to swap the transmission scanners and this may
occasionally be required when troubleshooting the system. However,
transmission scanners must be placed in their correct positions before the
system is returned to the customer. While transmission scanners are swapped,
it is not possible to perform a reference scan.
CardioMD AC Option
CardioMD Service Manual 12-3