Improved imaging of hepatic metastases with delayed pulse inversion harmonic imaging using a contrast agent SHU 508A: Preliminary study

To investigate the feasibility of delayed pulse-inversion harmonic imaging (PIHI) with the SH U 508A to improve imaging of hepatic metastases, we eval uated 20 patients with known hepatic metastases. Conventional ultrasound (U S) was performed before administration, and PIHI was performed 5 min after a bolus injection of 4 G of microbubble contrast agent (300 mg/mL of SH U 5 08A). Intense, homogeneous enhancement in the liver parenchyma was seen in all patients on delayed PTHI. In 10 patients (50%), 1 or more focal liver l esions that were not seen on unenhanced imaging were detected on delayed PI HI. When comparing 55 lesions that were seen on both techniques, delayed PI HI was superior to unenhanced imaging in terms of lesion conspicuity and le sion-to-liver contrast (p < 0.001, respectively). Delayed PIHI with SH U 50 8A can improve conspicuity of hepatic metastases and reveal focal liver les ions that are not detected on unenhanced imaging. (C) 2001 World Federation for Ultrasound in Medicine & Biology.