Advances in ultrasound systems for hepatic lesions in Japan

Use of intra-procedural fusion imaging combining contrast-enhanced ultrasound using a perflubutane-based contrast agent and auto sweep three-dimensional ultrasound for guiding radiofrequency ablation and evaluating its efficacy in patients with hepatocellular carcinoma

“…As previously reported [17,18], a perflubutane microbubble contrast agent (Sonazoid; Daiichi Sankyo, Tokyo, Japan) was injected into an antecubital vein at a dose of 0.2 ml via a 24gauge cannula and followed by injection of 2 ml of 5% glucose. CEUS images were acquired during three contrast phases, including the arterial phase (10-50 s after the start of injection), portal phase (80-120 s after the start of injection) and post-vascular phase (10 min after the start of injection).…”

“…CEUS images were acquired during three contrast phases, including the arterial phase (10-50 s after the start of injection), portal phase (80-120 s after the start of injection) and post-vascular phase (10 min after the start of injection). Using CEUS based on native tissue harmonic imaging at a low mechanical index (0.28) and a high frame rate (28-30 frames per second), the tumor vessels and staining could be evaluated in detail and in real time [17,18].…”

“…After suitable registration of the conventional US or CEUS and three-dimensional US volume data, the results of conventional US or CEUS scanning were viewed at the same time as the three-dimensional US volume data. Furthermore, we used GPS marks (Figure 2(b,c)) to confirm the location of the HCC [17][18][19][20][21][22] and to identify the margin of the treated HCC for evaluation of the efficacy of RFA immediately after the procedure. After registration of the CEUS and three-dimensional US images obtained during a single breath-hold, we set the GPS marks at the largest cut surface of the treated lesion, which was visualized as an HCC Figure 2.…”

“…The mean follow-up period after RFA was 21.4 (range [15][16][17][18][19][20][21][22][23][24][25][26][27] months. During this time, the only HCC that was evaluated as showing grade B ablation by both CEUS/US fusion imaging performed during RFA and CEMRI performed 1 month after RFA showed local tumor progression on follow-up CEMRI at 10 months after RFA.…”

Comparison Between Low Mechanical Index and High Mechanical Index Contrast Modes of Contrast‐Enhanced Ultrasonography: Evaluation of Perfusion Defects of Hypervascular Hepatocellular Carcinomas During the Post–Vascular Phase

“…During the PVP, typical HCCs (especially moderately to poorly differentiated HCCs) show hypoechoic perfusion defects because of the absence or lack of Kupffer cells compared with the adjacent hyperechoic liver parenchyma, in which the Sonazoid microbubbles are phagocytosed by the Kupffer cells . In contrast, because most well‐differentiated HCCs contain Kupffer cells, they do not exhibit perfusion defects . Distinguishing well‐differentiated HCCs from moderately to poorly differentiated HCCs is important because patients with well‐differentiated HCCs have a better prognosis than those with moderately to poorly differentiated HCCs .…”