The aim of this study was to evaluate capabilities of pulse inversion harmonic imaging (PIHI) with
Levovist in detection of liver
metastases compared with conventional ultrasound (US) and helical CT (HCT). One hundred sixty consecutive patients with known
malignancies were evaluated by conventional US, PIHI 2 min (40 patients) or 4 min (120 patients) after
Levovist injection and HCT. Conspicuity and number of the identified metastatic lesions were evaluated and assessed by statistical analysis (significance p<0.05). Mean diameter of the smallest identified
metastases was computed for conventional US, PIHI and HCT. In cases where PIHI revealed more lesions suspicious for
metastases than HCT, intraopertive US with surgical biopsy or 3-6-month US follow-up were performed to confirm diagnosis. Images were stored on magneto-optical disk and evaluated off-line by a dedicated software.
Metastases conspicuity was significantly improved on PIHI if compared with conventional US ( p<0.05). In 49 patients all the employed imaging techniques did not reveal any lesion, whereas in the remaining 111 patients, 28 patients revealed more than five metastatic lesions and 83 patients presented from one to five metastatic lesions. In comparison with conventional US, PIHI revealed more
metastases in 39/83 (47%), the same number in 44/83 (53%) and a lower number in 0/83 (0%) patients. In comparison with HCT, PIHI revealed more
metastases in 10/83 (12%), the same number in 61/83 (74%) and a lower number in 12/83 (14%) patients. Average number +/- SD (standard deviation) of confirmed
metastases for patients was 2.21+/-1.6 for conventional US, 3.1+/-2.44 for PIHI and 3.05+/-2.41 for HCT. The difference between PIHI and conventional US was statistically significant ( p<0.0001), whereas the difference between PIHI and HCT was not significant ( p=0.9). The smallest identified
metastases presented 3-mm mean diameter on PIHI, 5-mm on HCT and 7-mm on conventional US. PIHI with
Levovist is a reliable technique in
metastases detection.