Tissue Characterization Consulting

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3D Ultrasound tissue-mimicking quality assurance (QA) phantom

The quality of ultrasound images may be assessed at any organ such as liver or thyroid gland. However, it may be shown that mentioned organs are not adequately sensitive for assessment of contrast. The contrast ability of a scanner may be simply described as a cyst imaging capability. Axial and lateral resolution combined with slice thickness determine the contrast at various depths in the ultrasound image.

The cysts are represented in phantom as cylindrical scatter free targets arranged as shown by sketch. The phantom with described targets is very sensitive to the contrast ability of scanner.

Quality assurance of a scanner may be performed by repeated regular inspections of a scanner and comparison of the phantom B-images. The phantom is primarily intended for automatic processing and evaluation of B-images by special QA software.

Essentially the performance of a scanner can be estimated by imaging the different cylindrical targets at various depths. Since the attenuation, speed of sound and frequency dependent backscattering of phantom is comparable with living tissue, it is a quantitative approach for measurement of scanner quality.

PHANTOM SKETCH

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Subject to change without notice

⁺ Patent pending

Model PH160-0.5 NY⁺

SPECIFICATIONS

Material: Artificial foams

5mm interlaced slices type 1 and 2

Speed of sound:

c_ph=c_w + 30 m/s (1540 m/s at 20°C)

c_ph= speed of sound in phantom

c_w= speed of sound in water*

Attenuation:

Type 1: ~ 0.7 dB/cm/MHz**

Type 2: ~ 0.2 dB/cm/MHz**

Average 0.45 dB/cm/MHz

Targets: Type 2 foam.

Regular arrangement (see sketch)

Nylon filaments optional (0.3mm)

Scan window: Polyurethane

11cm x 5.5cm (0.25 mm)

Description: 20cm x 12cm x 6.5cm

Warranty:

Foam : 10 Years

Scan window: 2 Years

(under the condition of proper use)

*c_w - diagram

**Temperature dependence of Attenuation

_{a(f) = ao[1-t(T-To)}^e_]f ^g[1+k(T-To)]

a in dB/cm To=20^oC

T in degrees Celsius ( T>20^oC), f in MHz

type 1 type 2

_{ao 0.6663 0.2070}

t 0.1804 0.0834

e 0.4423 0.6990

g 1.3063 1.2960

^{k 0.0042 0.0076}