IEC TS 62558:2011 pdfダウンロード

IEC TS 62558:2011 pdfダウンロード。Ultrasonics – Real-time pulse-echo scanners – Phantom with cylindrical, artificial cysts in tissue-mimicking material and method for evaluation and periodic testing of 3D-distributions of void-detectability ratio (VDR)
Scope
This technical specification specifies essential characteristics of a phantom and method forthe measurement of void-detectability ratio for medical ultrasound systems and relatedtransducers. lt is restricted to the aspect of long-term reproducibility of testing results.
This technical specification establishes:
important characteristics and requirements for a TMM 3D artificial cyst phantom usinganechoic voids;
a design example of a 3D artificial cyst phantom, the necessary test equipment and use otrelevant computer software algorithms.
This technical specification is currently applicable for linear array transducers. A uniformitytest prior to void-detectability ratio (VDR) measurement is recommended.
NOTE The basic concept of the 3D artificial-cyst phantom may also be valid for other types of ultrasoundtransducers: however there is a need for further verification (see Annex D)
2Normative references
The following referenced documents are indispensable for the application of this documentFor dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including amendments) applies.
EC 60050-802, International Electrotechnica/ Vocabulary, Part 802: Ultrasonics
3 Terms and definitions
For the purposes of this document, the terms and definitions contained in IEC 60050-802 aswell as the following terms and definitions apply.
3.1
acoustic coupling mediummedium, usually fluid or a gel, that allows echo-free coupling of the transducer to the couplingwindow of the phantom.
3.2
artifactual signal
signal at a specific region in an image where no signal is expected (e.g. inside the image of a
void)
3.3
attenuation coefficient
at a specified frequency, the fractional decrease in plane wave amplitude per unit path lengthin the medium,specified for one-way propagation Units: m –1 (attenuation coefficient is expressed in dB m –1 by multiplying the fractional
decrease by 8,686 dB)
[IEC 61 391 -2:201 0, definition 3.4]
3.4
backscatter coefficient
at a specified frequency, the mean acoustic power scattered by a specified object in the 1 80° direction with respect to the direction of the incident beam, per unit solid angle per unit volume, divided by the incident beam intensity, the mean power being obtained from different spatial realizations of the scattering volume
Units: m –1 steradian –1
NOTE The frequency dependency should be addressed at places where backscatter coefficient is used, if frequency influences results significantly.
[IEC 61 391 -1 :2006, definition 3.6, modified]
3.5
backscatter contrast
ratio between the backscatter coefficients of two objects or regions
[IEC 61 391 -2:201 0, definition 3.8]
NOTE Backscatter contrast can be frequency-dependent but it is independent of any image system.
3.6
B-, C-, D-image
basic cross sectional presentations of 3D-images:
B-image is in a plane that is created by the acoustic scan-lines (scan plane);
C-image is in a plane perpendicular to the acoustic scan lines in the B-image;
D-image is in a plane perpendicular to B-image–plane and C-image-plane