Physics QA Flashcards
Who directs the QA program?
Physician
Who assesses quality of images?
Radiologist
Who are the 2 types of service personnel?
Manufacturer and biomedical personnel
What does the manufacturer do?
Preventative maintenance and repair equipment
What does the biomedical personnel do?
Acceptance testing when machine arrives on site to ensure safety.
What is acceptance testing?
Sophisticated testing before machines are operated.
What can a phantom assess?
Resolution, sensitivity, accuracy, etc
What is the key component to a good QA program?
Record keeping
How many times are is the accuracy checked in a year?
2-3 times under warrranty.
What is the AIUM 100?
Older testing device, encased in plastic case that contains 0.75mm steel rods arranged in groups and filled with water, 9% alcohol and algaecide
Why are AIUM 100’s not used?
No greyscale and do not attenuate.
What are the films made of on the tissue phantoms?
Saran or polyurethane
What are the containers made of?
ABS, PVC or acrylic
How is a “good” phantom characterized?
Attenuation coefficient, speed of sound, back scatter coefficient, elasticity, thermal properties
What can phantoms test?
Dead zone, detailed res, distance accuracy, image uniformity, depth of pen, cyst imaging capabilities
Describe the dead zone
Area in near field close to transducer (AKA: main bang)
What is an acceptable dead zone measurement?
15mm
When can the dead zone be very larger?
Old mechanical probes
Ability to separate interfaces along the path of the beam?
Testing axial resolution
Ability to separate interfaces across the beam?
Testing lateral resolution - measuring pins
What is lateral res dependant on?
Depth and focus
What test requires a different type of phantom?
Elevation resolution/slice thickness