Ultrasound QA FAQs
How does CIRS ensure the accuracy of my ultrasound QA phantom?
Positional accuracy of targets is controlled by an internal solid CNC (computerized numerical controlled) machined frame.
To ensure the acoustic properties of the tissue mimicking materials meet CIRS specifications, a sample from each gel batch manufactured is obtained. The speed of sound and attenuation of each sample is measured in the CIRS acoustics lab using time of flight and pulse echo techniques with an accuracy of +/- 1.5m/s for SOS and +/-0.02dB/cm/MHz for attenuation. These measurements are traceable to NIST.
Phantom contrast is controlled by the concentrations of scattering agent per unit volume of tissue mimicking material. A precision in contrast of +/- 1 DB is achieved by controlling the weight of the scattering material.
Young’s modulus of the tissue mimicking material used to manufacture elasticity targets is verified using a compression/deformation method on standardized samples.
Volume accuracy is controlled by measuring the weight of the target and the density of the tissue mimicking material used in its manufacture.
100% Final Inspection
A final inspection is performed on every ultrasound quality assurance phantom manufactured by CIRS. The inspection consists of two parts.
Part 1 - Visual Inspection of phantom housing, scanning surface and accessories.
Part 2 - Inspection with a diagnostic ultrasound machine for:
Air voids in gel and around masses
Straightness of masses
Integrity and placement of wires
Measurement of vertical wire distance.
The Diagnostic Ultrasound machine used for this test is calibrated to allow such measurements by a time-of-flight method.
What documentation is provided with my ultrasound QA phantom?
Each CIRS ultrasound quality assurance phantom comes with a detailed user guide and a certificate of compliance. Final inspection data is available upon request.
Can my ultrasound QA phantom be calibrated?
Calibration is not necessary. The phantom is sealed within an airtight enclosure and has no moving parts. There is no method by which CIRS ultrasound quality assurance phantoms can be calibrated after manufacture.
Can my ultrasound QA phantom be re-certified?
No, after original certificate of compliance at time of original manufacture, CIRS does not re-certify the acoustic or mechanical properties of the tissue mimicking materials or the location of the embedded targets.
Can my ultrasound QA phantom be re-inspected to ensure its suitability for continued use?
Yes, for a fee, CIRS can inspect your ultrasound QA phantom for signs of degradation that may impact the performance of the phantom. The inspection consists of four steps:
Step 1 – Careful visual inspection of phantom housing, scanning surface and accessories for signs of damage.
Step 2 – Weigh the phantom to quantify any desiccation. Weight loss can be used to estimate changes to SOS and attenuation within the phantom from time of original certification.
Step 3 – Thorough inspection with a diagnostic ultrasound system to identify any defects and confirm integrity of all targets. This essentially is the same final ultrasound inspection each phantom originally undergoes prior to being sold to the customer.
Step 4 – Generation of formal inspection report noting inspection results, special observations and manufacturers “opinion” regarding suitability for use. Final decision on usability resides with the customer and is dependent on their particular situation. Recommended non-warranty repairs will be quoted separately.
Can CIRS inspect phantoms supplied by other manufacturers?
No but contact CIRS customer service about trading your old phantom in for a discount on the purchase of a new CIRS phantom.