Cirs Beam Profile & Slice Thickness Phantom ATS 538NH Скачать руководство пользователя страница 9 | Manualshive

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BEAM PROFILE, FOCAL ZONE AND LATERAL RESPONSE WIDTH (CONTINUED)

Results

The beam profile should remain consistent from week to week, when using the
same instrument settings, transducer and the Model #538NH phantom. Compare
the test results obtained with a baseline or previous test. If the current image dem-
onstrates changes in the system, investigation should be made to determine the
cause.

ELEVATIONAL TESTING

A third component of spatial resolution,
the slice thickness, is often referred to as
the elevation resolution. A sound beam
travels through a medium along the beam
axis until it reaches an interface which is
perpendicular to the axis of the
sound beam, creating a two-dimensional
image. The image resolution is depedent
upon the degree of axial and lateral resolu-
tion of the diagnostic system. Elevational resolution displays reflections produced by
structures in front of or behind the beam's main axis. The effect of changes in the
slice thickness measurements are identical to those seen with axial and lateral reso-
lution. The smaller the slice thickness measurement the better the resolution, as the
slice thickness increases, the degree of spatial resolution decreases. In diagnostic
ultrasound, this factor becomes critical in determining an imaging system's ability
to detect and display small isolated lesions or structures of low contrast, which may
appear to be filled-in and go undetected.

ELEVATIONAL TESTING (CONTINUED)

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Содержание Beam Profile & Slice Thickness Phantom ATS 538NH

Страница 1: ...USER GUIDE U LTR A S O UND Q U ALITY ASSURANC E Beam Profile Slice Thickness Phantom Model ATS 538NH 900 Asbury Ave Norfolk Virginia 23513 USA Tel 757 855 2765 WWW CIRSINC COM ...

Страница 2: ...2 ...

Страница 3: ...IONS FOR USE 1 HANDLING AND CARE 1 GENERAL GUIDELINES FOR PERFORMING MEASUREMENTS 2 ESTABLISHING A BASELINE 3 3 TESTING PROCEDURES 4 BEAM PROFILE FOCAL ZONE LATERAL RESPONSE WIDTH 4 ELEVATIONAL RESOLUTION 6 4 SPECIFICATIONS 1 0 5 WARRANTY 1 1 ...

Страница 4: ...lice thickness or elevational resolution the third component of spatial resolution displays reflections produced by structures in front of or behind the beam s main axis The effect of changes in the slice thickness is identical to those seen with axial and lateral resolution The thinner the slice thickness the better the resolution as the slice thickness increases the degree of spatial resolu tion...

Страница 5: ...s the speed of sound and ultimately the perceived measurements The phantom should be stored at room temperature for at least 24 hours before use to ensure its core temperature is correct Most diagnostic imaging systems and tissue mimicking phantoms are calibrated at room temperature commonly referred to as 23 C To ensure measurement accuracy a thermometer strip is afﬁxed to the outside surface of ...

Страница 6: ...is each facility s responsibility to establish the magnitude of drift allowed before corrective action is warranted 3 Allowable deviation from baseline measurements The difference between the original baseline measurements and subsequent measurement should be calculated and recorded At some point the difference will be large enough that some action is required call service replace system etc Each ...

Страница 7: ...sus the almost homogeniticity of the amplitude in the far field The beam profile is affected by the performance of the transducer and the pulser receiver section of the imaging system 1 Place the phantom on a clean flat surface with 1 scanning surface positioned for use 2 Apply a liberal amount of acoustic coupling gel to the scanning surface It is suggested when evaluating array systems a low vis...

Страница 8: ... the individual transducer the frame rate must be decreased until the individual beam profile is displayed Depending upon the system it may be necessary to reduce the frame rate to zero 5 Freeze the image and obtain a hard copy 6 Examine the display The image should be hour glass in shape Note the presence or absence of any grating lobes which will be displayed as two horns on either side of the m...

Страница 9: ...erface which is perpendicular to the axis of the sound beam creating a two dimensional image The image resolution is depedent upon the degree of axial and lateral resolu tion of the diagnostic system Elevational resolution displays reﬂections produced by structures in front of or behind the beam s main axis The effect of changes in the slice thickness measurements are identical to those seen with ...

Страница 10: ...ize a snowplowing affect on the surface of the phantom However transducer faces with a high degree of curvature the use of a high viscosity gel is recommended to maintain good coupling 3 Adjust the instrument settings TGC output etc to establish baseline values for normal liver scanning If the penetration is such that the bottom of the phantom is seen the gain settings should be reduced such that ...

Страница 11: ...he frame rate must be decreased permitting a single slice thickness to be displayed De pending upon the system it may be necessary to reduce the frame rate to zero 6 Freeze image 7 Using the electronic calipers measure the distance from the scan surface to the center of the displayed slice thickness image 8 Again using the electronic calipers measure the thickness of the image This is the slice th...

Страница 12: ...e slice thickness and depth at which it occurred this area is the focal zone NOTE A correction factor of 0 94 adjusts for the speed of sound in ATS urethane 1450 m s Results The slice thickness of the beam should remain consistent from week to week when using the same instrument settings transducer and the Model 538NH phantom Compare the test results obtained with a baseline or previous test If th...

Страница 13: ...7 0 cm 12 0 x 7 0 cm 22 0 x 7 0 cm 19 0 x 7 0 cm URETHANEPROPERTIES Freezing point 40 C Melting point Above 100 C Speed of Sound 1450 m s at 23 Attenuation Coefficient 0 5 dB cm MHz measured at 3 5 MHz TARGETS Scattering plane oriented at 45 to the scan planes used to measure slice thickness and 90 to the beam profile scan plane Size 26 x 7 cm Depth 0 to 22 cm ...

Страница 14: ...to returning the product Visit https www cirsinc com distributors to find your local distributor If you purchased your product direct through CIRS call Customer Service at 800 617 1177 email rma cirsinc com or fax an RMA request form to 757 857 0523 CIRS staff will attempt to remedy the issue via phone or email as soon as possible If unable to correct the problem a return material autho rization R...

Страница 15: ...12 ...

Страница 16: ...puterized Imaging Reference Systems Inc has been certified by UL DQS Inc to ISO 13485 2016 Certificate Registration No 10000905 MP2016 COMPUTERIZED IMAGING REFERENCE SYSTEMS INC 900 Asbury Ave Norfolk Virginia 23513 USA TOLL FREE 800 617 1177 TEL 757 855 2765 FAX 757 857 0523 EMAIL admin cirsinc com www cirsinc com Technical Assistance 1 800 617 1177 ...

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