Introduction: Ultrasound is a mechanical wave, which is used to observe the inside of a human's body. It is a sound with frequency over 20 kHz. Recently, the ultrasound has become one of the most frequently used diagnostic methods. The ultrasound is described by frequency, wavelength and intensity. There are three different methods for obtaining an image using the ultrasound, A – mode, B – mode and M – mode. A – mode uses a single transducer, that scans a line through the body and marks echoes on a screen as a function of depth. B – mode represents a classic method of obtaining images and M – mode is used for its good display of axial and temporal resolution. Images are made with the help o fan ultrasound transducer, also called a probe. There are three types of ultrasound transducers, linear, convex and sector transducers. The structures shown on screen differ in colour. A hyperechoic signal in very bright and light in color, a hypoechoic signal appears darker and an anechoic signal appears black. Beside anatomical structures, the ultrasound images often show artifacts, resulting from the interactions of the ultrasound beam with the tissue or properties of the beam. Artifacts on an ultrasound image can be avoided by knowing how the ultrasound works, and understanding how the ultrasound beam spreads through tissues. Purpose: The aim of this diploma work is to show, describe and analyse the most common ultrasound artifacts that occur in ultrasound diagnostic. We will discuss when and why the artifacts occur, how we can show them on an ultrasound image ourselves and how we can get rid of them, when they prevent us from making a correct diagnosis. Methods: In this diploma work, we used a descriptive method with a review of literature. We collected the analysed material from the field of ultrasounds, mechanics of ultrasound and ultrasound artifacts. The reviewed materials were collected from Slovenian and English databases, with the help of Slovenian and English key words. At the end, we also tested the theory in practice and showed some artifacts with the help of phantoms. Results: The results present the articles we used to review the literature. It contains a detailed description of the fifteen most common ultrasound artifacts. We divided them according to occurrence in B – mode imaging and Doppler imaging, as well as the location were they are presented. We also preformed an experimental part, with which we proved the theory in practice with the help of phantoms. Discussion and conclusion: Ultrasound artifacts can be disruptive to our diagnosis or they can help us with it. Some artifacts we can avoid, some we can partly remove from the image and for others it is crucial that we recognise them because they cannot be removed or avoided. With the experimental part of this diploma work we confirmed the findings from the literature review in practice. We believe that our goal has been achieved.
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