Figure 3. VX-2 tumour in the rabbit liver, Case 11, left lobe. (a) Non-contrast tissue harmonic image. No tumour nodules were recognized with non-contrast ultrasound in this case. (b) Contrast-enhanced pulse subtraction harmonic images with Definity. One tumour nodule (arrow, white) and small nodule (arrow, grey) were observed as unenhanced focal lesions. (c) Near the same tumour as in (b), two other small tumours were demonstrated as unenhanced nodules in the surface area of the liver. (d) Histopathological findings. One implanted tumour nodule 17 mm in size was found in the liver (arrow, white). Small tumour nodule was observed around the implanted tumour (arrow, black), and was thought to be metastatic tumour nodules. Two tumour nodules 2 mm in size were seen in the surface area of the liver (arrows, grey).