Aim: This pilot study examines the question whether the transit time of an ultrasound echo enhancer, measured between the hepatic artery and the liver vein, can be used to differentiate between patients with and without liver metastases.
Method: The hepatic transit time of an ultrasound echo enhancer (Optison(R)) was determined using the pulse-inversion mode in patients suffering from gastrointestinal tumours. A group with histologically verified liver metastases was compared to a group without liver metastases.
Results: 24 patients have been included in the study so far. 7 patients had liver metastases from a still existing primary tumour (group A). Five patients showed liver metastases after removal of the primary tumour (group B). Six patients had a primary tumour, but no liver involvement (group C), and six patients had neither a primary tumour nor any liver disease. The mean hepatic transit time in group A and B came to 7.4 seconds. Group C and D had a transit time of 16 and 15.5 seconds, respectively. This shows a significant difference in hepatic transit time between patients with liver metastases (groups A and B) compared to those without (groups C and D). The presence of a primary tumour did not influence hepatic transit time.
Conclusion: In this first pilot study using the measurement of hepatic transit time it was possible to differentiate between patients with and without liver metastases.