The huge spreading of sonography in the field of nephrology led to the use of more performant equipment with construction of better quality images, but with an unfavorable signal/noise ratio, that bring to the generation of artifacts: false signals which creates images not corresponding to reality. Interaction between ultrasounds and biological structures generates a lot of physical phenomena: reflection, dispersion, absorption and diffraction; these elements create not only the images but also the artifacts. The artifacts, which don't correspond to anatomic reality, could be related to the extreme difference of acoustic impedance between the biological structures, or to an error in the settings of B-Mode and color-doppler functions. Sometimes they can be dangerous and make a diagnosis hard, but most of the time they are useful and pathognomonic of a lesion or physiologic structure. It's fundamental for the sonographer being able to discern between real to artifact; the rule is that everything that is repeated in all scans with different insonation angles is true, while what is not repeated in all scans can be an artifact.
Keywords: B-mode artifacts; Colordoppler artifacts; nephrological sonography.
Copyright by Società Italiana di Nefrologia SIN, Rome,Italy.