Fluke 84-340 User Manual

Nuclear Associates 84-340

General Purpose Multi-Tissue Ultrasound Phantom

February 2005
Manual No. 84-340-1 Rev. 2
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

Users Manual

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms

Table of Contents

Section 1: Introduction................................................................................................ 1-1

1.1 Introduction .................................................................................................. 1-1

1.2 Description................................................................................................... 1-2

Section 2: Testing Procedures ................................................................................... 2-1

2.1 Testing Procedures...................................................................................... 2-1

Section 3: Handling Instructions ................................................................................ 3-1

3.1 Handling Instructions ................................................................................... 3-1

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Introduction

Introduction

1

Section 1

Introduction

1.1 Introduction

This phantom is constructed from a patented solid elastic material called Zerdine™. Zerdine, unlike other
phantom materials on the market, is not effected by changes in temperature. It can be subjected to boiling
or freezing conditions without sustaining significant damage. Zerdine is also more effective than other
materials and allows more pressure to be applied to the scanning surface without subsequent damage to
the material. At normal or room temperatures the Zerdine material found in the General Purpose Phantom
will accurately simulate the ultrasound characteristics found in human liver tissue. The 84-340 contains
dense and cystic masses in a range of sizes, one high-density target and an assortment of nylon
monofilament target groups. The phantom is protected by an acrylic case and plastic membrane to
facilitate scanning and minimize desiccation. The 84-340 was designed to allow for assessment of
linearity, axial and lateral resolution, depth calibration, dead-zone measurement, and registration within
two different backgrounds of .5 and .7 dB/cm/MHz. This series of ultrasound phantoms, unlike human
subjects or random scannable materials, offers a reliable medium that contains specific, known test
objects repeatable qualitative assessment of ultrasound scanners over time.

1.2 Description

Background Material

The manufacturer maintains specific proprietary fabrication procedures that enable close control over the
homogeneity of Zerdine and the reliability of its acoustic characteristics from batch to batch. The speed of
sound in Zerdine can be adjusted between 1430 and 1650 meters per second. The acoustic attenuation
can be adjusted between .05 dB/cm/MHz and 1.50 dB/cm/MHz. The relation between the acoustic
attenuation A and the acoustic frequency F is of the form A = A°F
in the range of .8 to 1.10, indicating the proportional increase of the acoustic attenuation with frequency.
Backscatter characteristics can be adjusted through the addition of predetermined amounts of calibrated
scatter material. Zerdine can be molded into very intricate shapes and the material can be cured in layers
allowing the production of "multi-tissue" phantoms such as the 84-340. Zerdine like most other phantom
materials will desiccate if unprotected but Zerdine has a sponge like property. Any moisture lost to
evaporation will be reabsorbed when the material is immersed in water. Baring any damage to the case or
scanning membrane the phantom should lose only minimal amounts or moisture over time.

Near Field Resolution Target

The target consists of parallel .30 mm nylon wires horizontally spaced from center to center. Vertical
distance from the center of each wire to the top edge of the scanning surface ranges from 9 mm down to
1 mm in 1 mm increments (see Figures 1-1 and 1-4). This target is designed to measure a transducer's
dead-zone otherwise referred to as the “ring-down distance.”

with values of the power coefficient n

n

1-1

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Operators Manual

Figure 1-1

Lateral Resolution Targets

Two sets of targets are positioned at 2.5 cm and 10 cm deep to allow testing of both short and long
distance transducers. Extremely fine monofilament wires with a diameter of .1 mm are used to avoid any
possibility of one wire acoustically shadowing another. Five parallel wires are horizontally spaced
precisely 5, 4, 3, 2, and 1 mm distances apart from center to center (see Figures 1-2 and 1-4).

Figure 1-2

Vertical Resolution Target

The target consists of six pairs of parallel, .1 mm wires, horizontally spaced 6 mm apart from center to
center. The lower wire in each pair is horizontally offset from the upper wire by 1 mm to further reduce
any acoustic shadowing affects. The vertical distance between each pair of wires is 5, 4, 3, 2, 1, and .5
mm from center to center (see Figures 1-3 and 1-4). This target is designed to accurately assess vertical
resolution capabilities at a depth of 3 cm.

1-2

Introduction

Description

Figure 1-3

1

Vertical Plane Target

A group of .3 mm parallel wires are positioned 2 cm apart down the center of the phantom in a vertical
plane (Figure 1-4). When scanned from the top this target enables measurement of vertical linearity,
depth calibration and gain as a function of depth.

Horizontal Plane Target

A group of .3mm parallel wires are positioned 2 cm apart in a horizontal plane at mid-depth in the
phantom for calibration and linearity measurements (Figure 1-4).

Low Scatter Targets

A diagonal row of four cylinders having little or no scatter are provided in the phantom to test a machine's
ability to image cyst like structures of varying size and depth in two different backgrounds. Cylinder
diameters range from 8 mm at a depth of 8 cm to 2 mm at a depth of 2 cm (see Figure 1-4).

High Scatter Targets

A diagonal row of cylinders having scatter properties discernibly higher than the background are available
to test a machine's ability to image tumor like structures of varying size and depth in two different
backgrounds. Cylinder diameters range from 8 mm at a depth of 8 cm to 2 mm at a depth of 2 cm (see
Figure 1-4).

Figure 1-4

1-3

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Testing Procedures

Testing Procedures

2

Section 2

Testing Procedures

2.1 Testing Procedures

Dead-Zone Identification

The transducer should be placed firmly above the near field resolution target and perpendicular to the
wire plane. Dead-zone or the ring down distance can be defined as that distance between the
transducers face and the closest wire target to be resolved from the reverberation. If the first target to be
resolved is at 4 mm then the dead-zone distance is “something less than 4 mm.”

Assessment of Resolution

These measurements should be done at several sensitivities and depth levels to facilitate a thorough
evaluation. As defined by the AIUM standards committee, lateral resolution “at specified control settings
and range is the minimum lateral distance between two identical reflectors or scattering volumes at which
separate registrations can be clearly distinguished on the display.” Measurements should be made at
both 3 and 10 centimeters deep. Closer positioning of the transducers focal point to each target group
should result in better resolution. Assessment of vertical resolution should be done in the same manner
as assessment of lateral resolution using the vertical resolution target that is located approximately 30
mm from the scanning surface.

Depth Calibration

This measurement should be performed using the vertical plane targets. This group of wires should be
scanned linearly and perpendicular to the target plane. All wires should be displayed simultaneously
Measure the distance between two targets using the display markers and plot the values as a function of
true distance which is known to be 20 mm. Or, more simply, align the echoes to the display markers for
comparison.

Beam Width Measurement

A linear scan should be performed perpendicular to the vertical plane target. Some of the monofilament
wires are displayed as lines rather than points. The determined length of these displayed lines
demonstrates beam width as a function of depth in 2 cm increments.

Time-gain properties and sector scanner errors can be
evaluated using the vertical plane target in accordance
with suggested AIUM techniques. For targets with
minimum scattering, lower gain levels can be used,
however, higher gain settings enable evaluation at more
clinical type settings. When evaluating any machine,
settings should be recorded and remain consistent over
time. For further instruction on measuring performance
refer to Standard Methods for Measuring Performance of
Pulse-Echo Ultrasound Imaging Equipment, AIUM
Standards Committee, July 1990.

NOTE

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Handling Instructions

Handling Instructions

Section 3

Handling Instructions

3.1 Handling Instructions

1. Remove acrylic cover that protects the scanning membrane.

2. Fill the scanning cavity with water or suitable coupling material.

3. Apply the appropriate transducer to the membrane using normal pressure. The phantom material
and membrane are semi-elastic but can be damaged if excessive pressure is used.

4. Test ultrasound equipment in accordance with procedures suggested above or AIUM
recommendations.

5. When all testing is complete, remove excess coupling material and replace the protective acrylic
cover.

6. It is suggested that the phantom be stored at room temperature, avoid extreme temperatures.

7. Zerdine will desiccate over time if the water tight envelope is compromised. If there is a noticeable
change in the phantom or the case and/or membrane are damaged, the phantom should be
returned immediately for repair or replacement.

3

3-1

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms