7
SYSTEM COMPONENTS AND THEIR
FUNCTIONS
Gantry
The scanner is composed of the gantry and the patient
couch. The scanner uses a fan-shaped continuous X-ray
beam to scan the region to be examined. Transmitted X-
rays are detected and converted into electrical signals by
the SSMD.
The gantry includes the main body and its support mecha-
nism. The X-ray tube and the SSMD are mounted facing
each other on either side of the gantry aperture, and the X-
ray tube and detectors rotate continuously around the
aperture of the gantry. A slipring is employed to transmit
power between the gantry and the rotating X-ray high-volt-
age generator assembly.
The gantry can be tilted forward and backward in order to
perform tilt scanning. Three-dimensional alignment lights
are provided for setting slice positions. Gantry and patient
couch operating controls are provided on both sides of the
front of the gantry housing. The patient guide display indi-
cates the scan status to the operator and the patient. The
X-ray high-voltage generator is built into the gantry, and
the system employs a high-frequency inverter for generat-
ing and stabilizing the high voltage supplied to the X-ray
tube. The generator includes electronic circuits for control-
ling the speed of the rotating anode in the X-ray tube. Use
of a high-frequency inverter system results in high power
output combined with excellent stability. In addition, the
system is compact and light weight.
X-ray generator
This unit supplies stable high voltage to the X-ray tube unit.
The high-frequency inverter method is employed, resulting
in a light and compact design. This unit is incorporated in
the gantry.
• Max. power:
42 kW
X-ray tube
This is a large-capacity, high-cooling-rate X-ray tube that is
able to withstand continuous operation as in helical scan-
ning.
• Heat capacity:
4 MHU
• Cooling rate:
Max. 864 kHU/min
Patient couch
The patient couch is positioned in front of the gantry and
supports the patient. The entire unit moves vertically and
the top moves longitudinally. In an emergency, the couch-
top can be pulled out manually with very little effort. The
couch-top can also be lowered to a minimum height of
approx. 310 mm from the floor, facilitating transfer of the
patient from a low bed or stretcher.
MPDCT0290EA
