Intra‐operative contrast‐enhanced ultrasound improves image enhancement in the evaluation of liver tumors

BACKGROUND: Intra-operative hepatic tumor ultrasound assessment can be difficult in patients with abnormal hepatic parenchyma because of the inability to enhance echogenic differences. METHODS: Prospective pilot study of intra-operative ultrasound contrast enhancement in the evaluation of liver tumors to establish safety, dosing, and increased image enhancement with ultrasound contrast evaluation. A single bolus of perfluten lipid microspheres was then injected and ultrasound images were then re-recorded and saved. RESULTS: Twenty consecutive patients underwent contrast-enhanced ultrasound evaluation during the operative procedure. All patients received at least one bolus dose of microspheres (median 2 dose, range 1-3), without change in heart rate, blood pressure, end tidal CO(2), oxygen saturation, and sedation monitoring at the time of dosing and until 4 hr post-bolus doses. Two blinded independent readers found the contrasted images to have a statistically greater degree of enhancement (median improvement of 4, P = 0.01) and greater degree of size/border characteristics in the contrasted images (median improvement of 5, P = 0.01) for all histologies. In five patients, the extent of hepatic resection was altered from partial to complete lobectomy in order to obtain acceptable oncologic margin. CONCLUSIONS: Contrast-enhanced ultrasound is safe and effective in pre-resection and pre-ablation treatment planning.