Components Of Ct Scanner

Question 1

Gantry aperture

Answer 1

The external apparatus of a CT scanner, made of a ring or cylinder that the patient lies inside
What it does
Houses the X-ray tube, collimators, and detectors that spin around the patient to create 3D X-ray images
Features
The gantry can tilt forward or backward to accommodate different patients and examination protocols. The gantry’s circular opening, called the bore, slides over the patient table.
Design
The gantry is designed to be sturdy enough to support the internal components, while also being comfortable and accessible for patients.

Question 2

Microphone

Answer 2

There is also a microphone in the gantry that allows communication between the radiologic technologist and the patient throughout the scanning procedur

Question 3

Sagittal laser alignment

Answer 3

Patient positioning
The patient’s origin coordinates are created and transferred to the CT couch and laser. The sagittal laser position is set to define the patient’s origin.
Laser projection
Laser lines project the isocenter coordinates onto the patient’s skin. This allows for precise alignment with the CT scan.
Image verification
A sagittal scan of the patient is taken to verify the accuracy of the laser-table position system.

Question 4

Filter

Answer 4

Placed between x-ray source and patient
Removes low energy x-rays
Produces a more monochromatic beam
May be bowtie-shaped to even out attenuation once it passes through the body

Question 5

Collimator

Answer 5

Placed between filter and patient
Narrows beam to produce thinner slice
Less scatter from outside of the slice
Lower patient dose

Question 6

Detector array;

Answer 6

-solid state:
Most commonly used
Solid scintillator layer converts XR’s to light photons

• ionisation chamber detector (no longer used)
  Gas filled single chamber that is ionised by XR’s passing through