[Clinical ultrasound in nephrology].

When used correctly, modern ultrasound diagnostics are helpful for the nephrologist especially in emergency situations on the ward, in dialysis and in the emergency admission to quickly make the correct diagnosis or as a diagnostic gatekeeper to initiate the correct next diagnostic and therapeutic steps in a time-saving manner. In addition to conventional B‑mode/gray scale sonography and Doppler sonography, new ultrasound transducers with higher spatial resolution and above all contrast agent sonography have significantly expanded the technical possibilities and help nephrologists and internists to answer diagnostic and clinical questions. This particularly applies to the kidneys, which up to now could only be clarified by means of contrast-enhanced computed tomography or magnetic resonance imaging. This will allow the nephrologist in 2021 to amalgamate the clinical symptoms, imaging results and pathophysiological knowledge in an ideal, time-saving manner for the benefit of the patient.