Fig. 1

Gray-scale (a) and contrast enhanced ultrasound (b–d) images of a splenic benign nodular hyperplasia. The lesion is a round hypoechoic nodule in fundamental ultrasound (a). In the first seconds of the contrast-enhanced ultrasound examination (b), before the entrance of the contrast medium, the image is black because of the suppression of the fundamental signal. After about 10 s (c), the nodule is isoechoic to the surrounding spleen, but it becomes completely hypoechoic after a few more seconds (d)