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Summary of Contents for Gammex 403 GS LE
- Page 1 403 GS LE Precision Multi-Purpose Phantoms User’s Guide...
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Page 2: Table Of Contents
Table of Contents Introduction..................3 Caring for your 403GS LE.............4 Scanning your 403GS LE .............5 A Guided Tour of your 403GS LE..........6 Evaluating the Phantom..............7 Target Specifications..............11 Cystic Targets................11 Grey Scale Targets................11 Pin Targets..................11 Resolution Target Group..............11 Phantom Specifications..............13 Physical Specifications..............13 Tissue Mimicking Background Material.........13 Harmonic Imaging...............14 Grey Scale Applications.............15... -
Page 3: Introduction
Introduction The 403GS LE phantom is designed for measuring the image quality of high resolution ultrasound systems. Grey scale targets are provided for monitoring contrast and temporal resolution as well as distinguishing different intensities of brightness and border delineation capabilities of the ultrasound system. The 403GS LE offers carefully placed targets to measure resolution, depth of penetration and electronic caliper distance accuracy. -
Page 4: Caring For Your 403Gs Le
Return the phantom for inspection and/or repair if it has been dropped or damaged. Physical damage to the case will cause premature desiccation. Gammex recommends annual servicing of your 403GS LE to ensure proper operation. Our qualified service technicians will check for desiccation and provide any needed re-... -
Page 5: Scanning Your 403Gs Le
Scanning your 403GS LE • Always place the phantom on a stable, level surface for scanning. • The phantom comes ready to scan. Do not peel off the surface material. • Use water or a generous amount of coupling gel to ensure good transmission. Do not use mineral oil, baby oil or lanolin-based gels as a coupling medium. -
Page 6: A Guided Tour Of Your 403Gs Le
A Guided Tour of your 403GS LE The Precision Multi-Purpose Grey Scale Phantom 403GS LE provides a means for monitoring the image quality of ultrasound scanning systems. The tissue mimicking gel in the 403GS LE is ultrasonically similar to human tissue. This allows the use of normal scanner control settings and ensures that the measured performance closely approxi- mates the scanner’s performance in a clinical examination. -
Page 7: Evaluating The Phantom
Evaluating the Phantom Remember • The phantom comes ready to scan. Do not peel off the surface material. • Never press the transducer into the scanning surface. • Always clean and dry the scanning surface after each use. Never leave coupling gel or water on the scanning surface for more than a few hours. - Page 8 Move the transducer across the scanning surface while observing the locations of the targets. Notice how the smooth texture of the tissue mimicking gel emphasizes image non-uniformities and artifacts, making them easier to detect. Scanning an area without targets is a good way to test for image uniformity. Decrease gain controls to highlight pin targets.
- Page 9 Decrease the image depth and examine the axial resolution target group at 3 cm. Notice how the images of the lower pin targets may begin to merge. The smallest distance between two pins that can be clearly resolved with no vertical overlap is called the scanner’s axial resolution.
- Page 10 Measure the dimensions of the 6 mm cystic target to check the image geometry. Use the calipers to measure from top to bottom and side to side. Repeat with the other cystic target groups as part of the cyst imaging test. Decrease image depth to the minimum and examine the dead zone target group.
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Page 11: Target Specifications
Target Specifications Cystic Targets Diameters................2, 4, 6, and 10 mm Placement..............3, 7, 8, and 14 cm deep Speed of sound................1540±10 m/s Attenuation coefficient............0.05±0.01 dB/cm/MHz Grey Scale Targets Diameter....................10 mm Placement....................6 cm deep Speed of sound................1540±10 m/s Temperature dependence on speed of sound........1.5 m/s/ºC Contrast......... -
Page 13: Phantom Specifications
Phantom Specifications Physical Specifications Weight................Approx. 2.8 kg (6 lbs. 5 oz.) Dimensions................23.2 x 8.25 x 18.5 cm ................(9.25 x 3.25 x 7.25 in.) Scanning surface................Composite Film Case material.................Extruded ABS plastic Pin target material..............Nylon monofilament Tissue Mimicking Background Material Water-based gel with appearance of human tissue. Speed of sound................1540±10 m/s Attenuation coefficient............0.7±0.05 dB/cm/MHz ............0.5±0.05 dB/cm/MHz... -
Page 14: Harmonic Imaging
Recently, we have developed the capacity to measure the value of B/A for the tissue-mimicking materials in Gammex phantoms and have found it to lie in the range for human soft tissue, meaning B/A is between 6 and 7 _______________________________________ Gong, X. -
Page 15: Grey Scale Applications
Grey Scale Applications Metastases are sometimes slightly hyperechoic or hypoechoic compared with the sur- rounding tissue. If the scanner is not measuring grey levels accurately, the metastases may not be detected. The Quantitative Measurement ensures that the grey level signal is measured consistently. -
Page 16: System Linearity
System Linearity Ultrasound systems use special processing circuits to translate the amplitude of echoes into brightness levels on the video monitor. These circuits use mathematical functions that often produce an S-shaped curve when graphed. As shown in the figure below, each echo level produces a corresponding brightness level on the monitor. - Page 17 Changes in the shape of the S-curve result in different brightness levels for the same echo levels. Notice how the positions of the original brightness levels B–, B o and B + have moved to B – , B o and B + Changes in the system response can be identified by measuring the average pixel value of the grey scale targets and the background material as displayed on the video moni-...
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Page 18: Quantitative Measurement
Quantitative Measurement A target’s brightness level can be most accurately measured using electronic methods. The user defines a region of interest and the scanner determines the average pixel value. To reduce the effect of speckle and small variations in the targets, several meas- urements are taken and averaged. - Page 19 Measure and record the echo level of each target. Measure and record the echo level of the background material directly beside the anechoic target. Use as close to the same ROI as the target as possible. Un- freeze the image. Perform this process three times and record the average echo level for each grey scale target and for the background material on the data sheet.
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Page 20: Qualitative Measurement
Qualitative Measurement Video monitors on most ultrasound systems contain a “grey bar” which shows the grey levels available for display. Grey bars normally contain between sixteen and sixty-four steps of increasing brightness. Pixel values can be estimated by locating a grey bar step that approximates the brightness of the region of interest. -
Page 21: Phantom Desiccation
As the phantom desiccates, the scanning surface may flatten out. It is suggested that the phantom be sent in for rejuvenation once it has lost 15 grams of its total weight. When this occurs, contact GAMMEX (1-800-GAMMEX-1). -
Page 22: Product Warranty
THERE ARE NO EXPRESS OR IMPLIED WARRANTIES WHICH EXTEND BEYOND THE WARRANTIES SET FORTH ABOVE. SELLER MAKE NO WARRANTY OF MERCHANTABIL- ITY OR FITNESS FOR A PARTICULAR PURPOSE WITH RESPECT TO THE PRODUCTS OR ANY PARTS THEREOF. © 2003 GAMMEX 006260-00-06 Your warranty may be registered at http://www.gammex.com/warranty.asp... -
Page 23: Sales And Service
Sales and Service GAMMEX is committed to satisfying our customer’s needs. If you have any questions, comments, or suggestions regarding our products and service, please call or fax us. Sales Department hours are Monday through Friday, 7:30 am to 5:00 pm Central Time. - Page 24 Notes:...
- Page 25 Notes:...
- Page 26 Gammex, Inc. P.O. Box 620327 Middleton, WI 53562-0327 USA 1 800 GAMMEX 1 (426-6391) 1 608 828 7000 Fax: 1 608 828 7500 www.gammex.com e-mail: sales@gammex.com Gammex-RMI LTD Broadway Business Centre 32A Stoney Street Nottingham NG1 1LL United Kingdom +44 0115 9247188 Fax: +44 0115-9247189 e-mail: uksales@gammex.com...
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