ULTRASOUND ARTIFACTS

Ultrasound Artifacts



Abstract

Ultrasound imaging artifacts of acoustic source pertaining to tenacity, propagation route, and attenuation are reviewed. Lateral and axial tenacity limitations are artifactual in environment since a malfunction to determination means a decrease of minutia and two adjacent organisations may be visualized as one. Apparent tenacity close to the transducer (speckle) is not exactly associated to tissue texture but is a outcome of interference consequences from the circulation of scatterers in the tissue. Reverberation makes a set of identically positioned artifactual echoes distal to the genuine reflectors. The reflector likeness artifact is the production of things that are present on one edge of a powerful reflector, seeming on the opposite edge as well. Shadowing and enhancement are helpful artifacts for working out the environment of masses. Enhancement outcomes from reduced attenuation things in the sound route while shadowing outcomes from powerfully mirroring or powerfully attenuating objects. Additional artifacts encompass part width, refraction, multipath, edge lobe, grating lobe, focal enhancement, comet follow, ring down, pace mistake, and variety ambiguity.

Reverberation

Strong spatial tissue heterogeneity also creates acoustic noise through multiple scattering known as pulse reverberations. The reverberations produce a tail added to the propagating pulse, and is observed as additive noise in the image. This effect is strongest when imaging through the body wall, as this is composed of irregular mixtures of muscles, fat, and connective tissue. Note that the effect is also important in strongly heterogeneous objects, for example the female breast. (Zdero 2002)

Carotis short axis

Carotis long axis

The lumen (inside of the artery) of the artery is corrupted by reverberation noise from the layers above. The problems related to aberration and reverberations in medical ultrasound imaging can be summarized as follows: (Vasilyev 2006)

Reduced spatial resolution and contrast the images.

There are large differences in image quality between patients, making it difficult to properly diagnose all cases.

The diagnose may be very uncertain for some patients, which makes more investigations necessary. This increases the cost for the public health service.

Increasing obesity in the population will probably increase problems related the aberration and reverberations.

If solved, may provide more reliable and correct diagnosis for large groups of patients, and may lead to the possibility of using medical ultrasound in new clinical areas.

Shadowing

Ultrasound imaging artifacts of acoustic origin relating to resolution, propagation path, and attenuation are reviewed. Lateral and axial resolution limitations are artifactual in nature since a failure to resolve means a loss of detail and two adjacent structures may be visualized as one. Apparent resolution close to the transducer (speckle) is not directly related to tissue texture but is a result of interference effects from the distribution of scatterers in the tissue. (Szabo 2004)Reverberation produces a set of equally spaced artifactual echoes distal to the real reflectors. The mirror image artifact is the presentation of objects that are present on one side of a strong reflector, appearing on the other side as well. Shadowing and enhancement are useful artifacts for determining the nature of masses. Enhancement results from low attenuation objects in the sound path ...