Diagnostic imaging methods include non-invasive imaging methods for internal body structures used for diagnostic or therapeutic purposes. The most commonly used methods are: ultrasonography, radiography, computed tomography (CT) and magnetic resonance imaging (MRI). Ultrasonography uses an ultrasound beam to obtain a two-dimesnional (three-dimensional) image of a body cross-section, and the basic work principle is based on the piezoelectric effect. Short wave pulses are spread throughout the body during which they collide with tissues of different density and sound impedance. The reflected pulses return back to the transducder which is in this case both, a detector and an emitter of ultrasonic pulses. X-rays that are penetrating the body, which is positioned between the source and the X-ray detector are used in radiography. During their way through the body X-rays are partially absorbed. The absorption intensity is indicated by the color scale. Computed tomography gives a stratified view of body slices using a fan-shaped X-ray beam. The intensity of X-rays is measured using a series of detectors and it depends on the tissue attenuation coefficient. Magnetic resonance imaging is an imaging method that uses a magnetic field in combination with radio-waves instead of ionizing radiation. It is based on the distribution of hydrogen atoms in the body and the relaxation times which represent the signal that MRI machine detects. Artifacts are the most common problem in the interpretation of results of diagnostic imaging. Some of the problems that may occur in certain diagnostic methods are high cost, scan duration and high radiation dose. Each diagnostic method is specific and it reflects a specific tissue property. Methods can be used individually to obtain a definitive diagnosis of a pathological condition, while sometimes a combination of these methods may be required.