Contrast-enhanced intraoperative ultrasonography equipped with late Kupffer-phase image obtained by sonazoid in patients with colorectal liver metastases

Abstract

Aim: To find occult metastases during hepatectomy in patients with colorectal cancer liver metastases (CRCLM), contrast-enhanced intraoperative ultrasonography (CE-IOUS) was performed using a new microbubble agent, sonazoid, which provides a parenchyma-specific contrast image based on its accumulation in the Kupffer cells.

Methods: Eight patients with CRCLM underwent CE-IOUS using sonazoid before hepatectomy. The liver was investigated during a late Kupffer-phase imaging, which is a valuable characteristic of sonazoid.

Results: CE-IOUS using sonazoid provided the early vascular- and sinusoidal-phase images for 10 min followed by the late Kupffer-phase image up to 30 min after the injection of sonazoid. IOUS did not provide new findings of metastatic lesion in the 8 patients. However, during the late Kupffer-phase image of sonazoid, a metastatic lesion was newly found in two of the 8 patients. These newly detected lesions were removed by an additional hepatectomy and histopathologically diagnosed as a metastasis.

Conclusion: CE-IOUS using sonazoid can allow surgeons to investigate the whole liver with enough time and to find new metastases intraoperatively.

Figures

Figure 1

IOUS and CE-IOUS views of a metastasis at the Segment 8. A: The metastatic lesion was unclearly detected as a slightly hypoechoic mass; B: CE-IOUS view of the same lesion. The metastatic lesion was shown as a distinct hypoechoic mass at the late Kupffer-phase.

Figure 2

An occult metastasis. A: An occult metastasis at the segment 4 only detected by CE-IOUS. A clear hypoechoic mass (approximately 6 mm in diameter; black arrow) was newly detected at the delayed Kupffer phase. This metastatic lesion could not be found by CT, MRI, and IOUS. B: Macroscopic view of this metastasis (arrow).

Figure 3

Preoperative CT and SPIO-MRI, and CE-IOUS. A: An enhanced-CT view and an ill-defined low density mass was detected at the segment 7 (arrow); B: A SPIO MRI view and an ill-defined high intensity mass was detected at the segment 8 (arrow); C: CE-IOUS view at the delayed Kupffer phase and a well-demarcated hypoechoic mass was detected by CE-IOUS.

Figure 4

Preoperative CT and SPIO-MRI, and CE-IOUS. A: An enhanced-CT could not detect any lesion at the Segment 6 (arrow); B: A SPIO MRI view could not detect any lesion at the Segment 6 (arrow); C: CE-IOUS view at the delayed Kupffer phase and a small hypoechoic mass partially containing a isoechoic lesion was detected by CE-IOUS.