TYPES OF QC TEST

Unit Assembly Evaluation

This is done by conducting visual inspection of the system, room as well as through discussion with the operator in-charge as to ensure all mechanical movements and locks are functioning properly.
This allows all interlocks, indicators and mechanical support devices for the X-Ray system and its respective associated receptor or bucky assembly are operating appropriately and safely.

Tube Voltage Accuracy (Accuracy of kV):

To determine the accuracy of the tube voltage.
It is important to keep it precise as it affects the quantity and quality of X-Rays reaching the image receptors.

Exposure Timer Accuracy:

To determine accuracy of the exposure timer and repeatability of radiation output.
If the exposure time set on an X-Ray machine is inaccurate, the radiographic image can be under-exposed or overexposed.
This may cause diagnostic imaging to be rejected and repeated, resulting in unnecessary exposures to the patient/user.

Coefficient of Linearity:

To assess the proportionality between tube output and the tube voltage over the full range of the tube currents and times.
Generally, it is essential that X-Ray machines produces proportional change in exposure under different variation of milliampere (mA).

X-Ray Beam Limitation

X-Ray Beam/Light Field Alignment, X-Ray Beam/Light Field Centering (at 1.0m FID) and Beam Perpendicularity.

To determine the accuracy of the congruency of the X-Ray beam with the light beam and evaluate the X-Ray beam alignment with the center of the light beam.

Collimation Light Field Illumination (At 1.0m from Focal Spot).

X-Ray Beam Filtration (HVL Measurement)

To assess the X-Ray Beam Quality of the X-Ray System.
X-Ray beam quality determines the image quality due to its ability to affect image contrast.
HVL is an important quality control test as it is used to measure whether or not there is sufficient filtration in the x-ray beam to remove low energy radiation, which can be damaging.

Image Quality

To evaluate image resolution and contrast of the system.
This is to ensure that image quality meets the required standards and is able to be accepted to produce images with diagnostic values.
Low quality images will cause rejected radiographic image and retakes to be taken which forces unnecessary exposures.

AEC Test (Automatic Exposure Control)

Repeatability

To assess the AEC performance of the system so it maintains at a consistent image optical density as patient thickness when image modes change, and when during the alteration of the optical density function control (density control function).

Detector Matching

To assess the AEC performance of the system so it maintains at consistent image optical density as different AEC detector position are selected.

Consistency of Film Density with Change in KiloVolt (kV)

To assess the AEC of the system so it maintains at a consistent image optical density as KiloVolt (kV) setting changes.

Consistency of Film Density with Change in Phantom Thickness

To assess AEC performance of the system so it maintains at a consistent image optical density as KiloVolt (kV) setting changes.

Focal Spot Size Measurement

To determine the focal spot size of the X-Ray Tube.
The test is to ensure that focal spot size and shape does not change drastically due to bombardment of electrons on the target.
Focal Spot Size has the ability to record sharper details of the image produce which is why it is important to periodically test for any changes on the Focal Spot Size over time.

Radiation Leakage

Radiation Leaks refers to unwanted radiation which transmitted through the protective shielding other than the primary beam.
This test is to determine any areas of radiation leakage through the X-Ray tube housing and to determine the leakage reading.

Scattered Radiation

Scatter radiation refers to a type of secondary radiation that spreads out in different directions from a radiation beam interacts with an object or medium.
This procedure is used to check the radiation safety level for the surrounding area of X-Ray room prior to operating the equipment.
In an X-Ray procedure, the patient’s body is the object that deflects radiation and causing it to scatter. This may cause exposure to people nearby as well as other parts of the patient’s body.