Doppler perfusion index and contrast-enhanced ultrasound in patients with colorectal cancer liver metastases.

Abstract

To assess the value of the Doppler perfusion index (DPI) and contrast agent for the detection of liver metastases in patients with colorectal cancer. DPI was measured in 18 patients with colorectal cancer liver metastases and 18 control subjects. Sixteen patients were underwent contrast-enhanced ultrasonography (CEUS). patients with liver metastases had significantly greater DPI than control group (0.39 +/- 0.10 vs. 0.19 +/- 0.07, p < 0.05). Sixteen liver metastasis lesions underwent a rapid wash-out of contrast agent during the portal venous phase followed by a complete wash-out of SonoVue during the sinusoidal phase and were differentiated as "fast-in and fast-out" contrast enhancement patter. Another 3 lesions which were not found by baseline ultrasonography were detected to be enhancement defects at sinusoidal phases by CEUS. DPI is a sensitive index in detection of colorectal liver metastases; if used combined with contrast agent, much more occult liver metastasis would be detected by ultrasonography.