We have noted a new characteristic colour Doppler (CD) appearance on liver ultrasound after giving the echoenhancing agent Levovist (Schering Health Care). Levovist is an intravenous microbubble ultrasound contrast agent which improves a Doppler study by increasing the signal intensity from blood vessels by 10–25 dB; the duration of useful enhancement lasts 1–5 min. 1, 2 It is not regarded as producing parenchymal enhancement, but while doing Levovist ultrasound studies of the abdomen, we noted strong, transient, wide-frequency CD signals in the liver parenchyma, appearing on real-time colour Doppler scanning as flashes of polychromatic colour for several minutes after intravenous injection. Characteristic features were a transient nature, with the effect disappearing after a few frames when CD was switched on, parenchymal location, and a tendency to cluster at the level of the focal zone of the ultrasound beam. In a prospective study of 40 patients and volunteers receiving Levovist (between 1–5 doses of 2· 5 g each) we recorded this effect on all occasions, with various commercial ultrasound machines. Effects persisted for up to 30 min, long after blood-pool enhancement had disappeared. Focal liver lesions show as defects in the colour mosaic and are particularly well seen if scanning is done after a delay of 5–10 min from injection (figure).