GE LOGIQ 200 Quality Assurance Manual page 70

GE MEDICAL SYSTEMS
REV 1
2-13 Performance Variation Tests Probe #1 & #2 (cont'd)
2-13-6 Lateral Resolution
Refer to
LATERAL resolution defines how well the system/probe can display two targets side by side. The
smallest visible distance of two targets on the same horizontal plane is the Lateral Resolution.
Note the measurement in millimeters on the QA Procedure.
2-13-7 Axial Resolution
Refer to
AXIAL resolution defines how well the system/probe can display two targets above and below each
other. The smallest visible distance of two targets on the same vettical plane is the Axial resolution.
Note the measurement in millimeters on the QA Procedure.
2-13-8 Contrast Resolution (Optional)
Refer to
Evaluate the Contrast (gray scale) Targets. The point is not how any ONE of them looks but
how well defined they are from each other, and from the background material.
Under each object number, record the following information for five of the contrast targets:
If there are less than five targets indicate with N/A.
2-13-9 Noise Level
Refer to
Ensure that room lighting is set to normal scanning conditions. Describe the lighting conditions
for repeatability during the next QA check.
Adjust the system settings that produces a clean image.
Wipe all the gel from the probe face, and set the probe in its holder. With transmit power at a
fixed value, adjust the overall gain, until the far field image (beyond 3cm) begins to fill with noise.
Reduce the overall gain until the last of those noise "speckles" disappear.
Note the Gain, TCG and any other relevant system parameters on the scan image.
Attach the hard copy to QA Testing Procedure when it is printed.
ULTRASOUND QUALITY ASSURANCE REFERENCE MANUAL
Section 4-2, Step 1 for further details.
Section 4-2, Step 2 for further details.
Section 4-2, Step 6 & 7
Object Depth - in centimeters
Object Size - in millimeters
Object Contrast - level
Object Detectability - Complete, Partial or Not Seen
Change for the worse - Yes or No
Section 4-2, Step 5 for further details.
for further details.
2-6
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