A round echogenic structure is already visible at the top of the left atrial appendage. After administration of a bolus of 0.5 mL SonoVue a contrast filling defect appears in this area as a sign of a thrombus. With a mechanical index of 0.09 (Vivid 7, 6TC probe, CPI (Coded Phase Inversion)) there is no swirling in the near field of the transducer.

The position of the focus (here 11 cm) is choosen as far away from the transducer as possible, a setting we use with almost all contrast studies. If these settings are not satisfactory, try out an increase of the mechanical index to 0.12 to 0.15.

As an alternative, my personal favorite in reduced imaging quality is to increase the frequence to 3.0/4.7 MHz, MI = 0.12. For structures far away from the transducer an attempt with 3.0/6.0 MHz (octave modus) may be worthwhile.