Figure 4. 33-year-old patient with a primitive neuroectodermal tumour (PNET) of the chest wall with infiltration of pulmonary tissue. (a) On colour Doppler ultrasound a vessel was seen centrally in the tumour. (b) A monophasic high impedant arterial flow pattern was seen suggesting an intercostal artery (ICA). (c) In the periphery of the lesion a monophasic low impedant arterial flow pattern was seen suggesting a peripheral bronchial artery (BA) origin.