IEC 61391-2:2010 pdf – Ultrasonics – Pulse-echo scanners- Part 2: Measurement of maximum depth of penetration and local dynamic range.
NOTE Exampt.e of discret. operating mod., are A-mode (A), U-mode (U), static B-mode CaB). real-lime B- mode (B). continuous wave Doppler (cwD), puisd Doppt.r (0). slatic flow-mapping (aD) and rai-iirnq flowmapping Doppter (rO) generally using only on. type of acoustic pulse at a given deplh
(IEC 62127-1:2007, definitIon 3.39.21
operating mode (combined)
mode of operation of a system that combines more than one dlscr.t. op.rating mod.
(IEC 62127-1:2007, definitIon 3.39.11
perfect planar (or specular) reflector
an interface that has a reflection coefficient of 1.0 and whose dimensions are lage compared to the local width of the ultrasound beam
NOTE I Tb. pr.ssur.-.mphlud. r,ft.clon co.ffici.nt ot a waler-to-air interfac, is 0,9994 (derived from 2* 14S0 000 kgrn”a’ and Za • 413 kgm2a-’)
NOTE 2 In practical measurements a variety of Lergets may be used. These can all be referred to the perfect planar reflector by calculation or by cereful companson.
a volume of material behaving in essentially the same manner as tissue of the same dimensions, with respect to absorption and scattering of the ultrasound radiation in question, used for dosimetry or for the evaluation of sonographic images in diagnostic sonography (see tissu, mimicking phantom)
(IEC 60050-881:1983, 881-12-54 modifiedj
pulse-echo t.chnlqu.
method of interrogating a region by insonifying it with pulsed sound beams and detecting and displaying echo signals arising from scatterers or reflectors
reflection coefficient (sound pressure)
ratio of the reflected pressure amplitude to the incident pressure amplitude for plane waves incident perpendicularly on a smooth interface separating two media
scan line
see acoustic scan line
scan plan.
acquired Image plane containing the acoustic scan lines
scan volume
volume from which echo data are acquired and that contribute to a 3D. image
minimum reflection coefficient in water of a plane reflector, oriented and positioned for macimum response, which produces a display threshold
NOTE For the purpose of this standard, the maximum depth Of penetration for visualizing background ecfloe in a phantom is used as en indication of sensitivity.
sp.clflc attenuation co.fflcl.nt
at a specified frequency, the slope of attenuation coefficient plotted against frequency
Units: dB m-1MHz-1
speckle pattern
image pattern or texture, produced by the interference of echoes from the scattering centres in tissue of tissue-mimicking material
(3,30 of IEC 61391.1:20061
statistically independent images
images acquired from planes or directions such that the normalized cross-correlation of the underlying speckle pattern over a fixed region of interest, prior to any speckle reduction smoothing, is less than 0,2
NOTE StatistecaCy independent Images are obtained from a phantom conIalnwg randomly dlstflbuted scatterer. by translating th. scanning plane, st,ring th, bear,,, .16,. such th.t th. underlying ip.ckl. pattern change. aufticiently to reduce the correlation Image. whose speckle target cross-correlation is —0,2 or lower are sufficiently dc-correlated to Implement measurements en tfles standard
test object
device containing one or more groups of object configurations embedded in a tissue- mimicking material or another medium (see also phantom, tissu.-mlmlcklng phantom)
[IEC 61391-1:2006. definition 3.331
tlssu..mlmlcklng mat.rlal
material In which the propagation velocity (speed of Sound). reflection, scattering, and
attenuation properties are similar to those of soft tissue for ultrasound In the frequency range
1 MHZ to 15MHz
[IEC 61391.1 :2006. definition 3.36, modifiedj
tissue-mimicking phantom
object comprising tissue-mimicking material
4 General requirement
The manufacturer’s specification shall allow comparison with the results obtained from the tests described in this standard.
5 EnvIronmental conditions
All measurements shall be performed within the following ambient conditions:
– temperature. 23°C ± 3°C;
– relative humidity, 45 % to 75 %:
— atmospheric pressure, 86 kPa to 106 kPa.
Properties of ultrasound phantoms, such as speed oF sound and attenuation coefficient, are known to vary with temperature. Consult the specifications published by the phantom manufacturer to determine whether the expected acoustic properties are maintained under the above environmental conditions. lf not, the environmental conditions over which expected andreproducible results can be obtained from the phantom or test object shall be adopted fortests.