ATS 531 User manual

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Ultrasound Imaging Phantoms
www.atslaboratories-phantoms.com
Model 531
Gray Scale Phantom Instructions Manual
Revised January 2015
Made in USA

Introduction
Quality assurance tissue-mimicking phantoms are used to evaluate the accuracy and performance of ultrasound
imaging systems. The phantoms mimic the acoustic properties of human tissue and provide test structures within
the simulated environment. They are essential to detect the performance changes that occur through normal
aging and deterioration of system components. Routine equipment performance monitoring can reduce the
number of repeat examinations, the duration of examinations and maintenance time.
This phantom is constructed of a rubber-based tissue-mimicking material developed by ATS Laboratories. This
material extends the useful life of the phantom by avoiding problems due to melting, freezing, dehydration and
breakage from dropping which are common with hydrogel (water-based) phantoms. By eliminating these
problems, the durability, quality and reliability of this product is guaranteed for three years.
The acoustic properties of all biologic and non-biologic materials are affected by temperature variations. Most
diagnostic imaging systems and tissue-mimicking phantoms are calibrated at room temperature, commonly
referred to as 23°C. To ensure measurement accuracy ATS incorporates a thermometer strip affixed to the outside
surface of the phantom housing.
The sound velocity of most diagnostic imaging systems is calibrated to 1,540 meters per second (mps), the
assumed average velocity of sound through human soft tissue. The rubber-based tissue-mimicking material has a
sound velocity of 1450 mps at room temperature (23°C).
Product Description
The Model 531 Gray Scale/Displayed Dynamic Range phantom is composed of a rubber-based tissue mimicking
material. The phantom is designed to evaluate an imaging system’s gray scale processing and display dynamic
range. It is provided with 10 levels of contrast relative to the background ranging from -15 to +15 dB.
Tests Performed
Gray Scale Displayed Dynamic Range
Specifications
General
Tissue Mimicking Material
Overall dimensions
25 x 12 x 7 cm*
Type
Rubber-Based
Weight
2 Kg*
Freezing Point
< -40°C
Scan Surfaces
2
Melting Point
> 100°C
Scan Surface Dimensions
25 x 7 cm*
Background Attenuation
Speed of Sound
0.5 dB/cm/Mhz (measured
at 3.5 MHz)
1450 m/s at 23°C
Gray Scale Target Structures
Type
Echogenic, Cylindrical
Number of Targets
10
Diameter
25 mm
Interval Spacing (center to center)
40 mm ± 1 mm
Depth
40 & 80 mm ± 1 mm
Contrast relative to background material (dB)
+15, +12, +9, +6, +3, -3, -6, -9, -12, -15
*Nominal dimensions

!
Gray Scale & Displayed Dynamic Range
Description and Reason for Testing
Gray scale or gray scale processing uses the amplitude of the echoes received to vary the degree of
brightness of the displayed image. The adjustment of the echo signal required to go from a just
noticeable (low gray scale level) echo to the maximum echo brightness is referred to as the displayed
dynamic range. Clinically, gray scale processing and displayed dynamic range allow echoes of varying
degrees of amplitude to be displayed in the same image.
Test Procedure
1. Place the phantom on a clean, flat surface with the scan surface positioned for use.
2. Apply an adequate amount of low viscosity gel to the scan surface.
3. Adjust the instrument settings (TGC, output, etc) to establish baseline values for “normal” liver
scanning. If the bottom of the phantom is seen, adjust the gain setting until the image goes entirely
black. Record these settings on the quality assurance record. These settings should be used for
subsequent testing.
4. Position the transducer over the gray scale target group until a clear image is obtained.
5. Freeze image and obtain a hard copy.
6. Examine the image. The targets should appear circular in shape, with clear sharp edges and vary in
the degree of brightness ranging from low to high levels of contrast. The presence or absence of any
shadowing behind the structures should be noted.
7. All findings should be documented on the quality assurance record.
Results
This target group varies in echogenicity and provides a good indication of the performance of the gray
scale processing and displayed dynamic range. The test should be compared with a baseline test using
the same instrument settings, to determine if any change in the characteristics of the target group has
occurred with time. If changes are noted, they should be investigated.

Care of the Rubber-Based Phantoms
For best results the phantom should be kept clean at all times and stored at room temperature.
In particular a build-up of dried coupling gel on the scan surface should be avoided. The
phantom may be cleaned with warm water using a lint free cloth. Particularly stubborn stains
and dirt may be removed with a mild household cleaner. The use of petroleum solvents should
be avoided since they may adversely react with the rubber-based material.
Warranty
Statement of Warranty
ATS Laboratories, Incorporated warrants this rubber-based phantom for it’s lifetime from the
date of delivery to the purchaser, that the Phantom is free from functional defects in materials
and workmanship. The lifetime of this phantom is estimated to be 10 years from the date of
manufacturing. If ATS Laboratories, Incorporated, deems the phantom to be defective, at its sole
option, the Phantom will be repaired or replaced free of charge, in a reasonable amount of
time.
ATS shall not be otherwise liable for any damages, including but not limited to incidental
damages, consequential damages, or special damages.
There are no express or implied warranties which extend beyond the warranties as stated
below.
Conditions of Warranty
1. The defect must be reported and the Phantom returned within the warranty period.
2. The Phantom must be packaged properly to avoid damage during shipping.
3. All transportation charges will be paid by the purchaser.
Invalidation of Warranty
1. If the phantom has been altered or repaired other than by ATS Laboratories, Incorporated.
2. If the phantom has been subject to abuse, misuse, negligence or accident.
3. If the purchaser has exposed the Phantom to petroleum solvents.