Zhong-Zhen Su

Intra-biliary contrast-enhanced ultrasound for evaluating biliary obstruction during percutaneous transhepatic biliary drainage: A preliminary study

OBJECTIVES The aimed of this study was to investigate the value of intra-biliary contrast-enhanced ultrasound (IB-CEUS) for evaluating biliary obstruction during percutaneous transhepatic biliary drainage (PTBD). MATERIALS AND METHODS 80 patients with obstructive jaundice who underwent IB-CEUS during PTBD were enrolled. The diluted ultrasound contrast agent was injected via the drainage catheter to perform IB-CEUS. Both conventional ultrasound and IB-CEUS were used to detect the tips of the drainage catheters and to compare the detection rates of the tips. The obstructive level and degree of biliary tract were evaluated by IB-CEUS. Fluoroscopic cholangiography (FC) and computer tomography cholangiography (CTC) were taken as standard reference for comparison. RESULTS Conventional ultrasound displayed only 43 tips (43/80, 53.8%) of the drainage catheters within the bile ducts while IB-CEUS identified all 80 tips (80/80, 100%) of the drainage catheters including 4 of them out of the bile duct (P<0.001). IB-CEUS made correct diagnosis in 44 patients with intrahepatic and 36 patients with extrahepatic biliary obstructions. IB-CEUS accurately demonstrated complete obstruction in 56 patients and incomplete obstruction in 21 patients. There were 3 patients with incomplete obstruction misdiagnosed to be complete obstruction by IB-CEUS. The diagnostic accuracy of biliary obstruction degree was 96.3% (77/80). CONCLUSION IB-CEUS could improve the visualization of the drainage catheters and evaluate the biliary obstructive level and degree during PTBD. IB-CEUS may be the potential substitute to FC in the PTBD procedure.

Assessment of radiofrequency ablation margin by MRI-MRI image fusion in hepatocellular carcinoma

AIM To investigate the feasibility and clinical value of magnetic resonance imaging (MRI)-MRI image fusion in assessing the ablative margin (AM) for hepatocellular carcinoma (HCC). METHODS A newly developed ultrasound workstation for MRI-MRI image fusion was used to evaluate the AM of 62 tumors in 52 HCC patients after radiofrequency ablation (RFA). The lesions were divided into two groups: group A, in which the tumor was completely ablated and 5 mm AM was achieved (n = 32); and group B, in which the tumor was completely ablated but 5 mm AM was not achieved (n = 29). To detect local tumor progression (LTP), all patients were followed every two months by contrast-enhanced ultrasound, contrast-enhanced MRI or computed tomography (CT) in the first year after RFA. Then, the follow-up interval was prolonged to every three months after the first year. RESULTS Of the 62 tumors, MRI-MRI image fusion was successful in 61 (98.4%); the remaining case had significant deformation of the liver and massive ascites after RFA. The time required for creating image fusion and AM evaluation was 15.5 ± 5.5 min (range: 8-22 min) and 9.6 ± 3.2 min (range: 6-14 min), respectively. The follow-up period ranged from 1-23 mo (14.2 ± 5.4 mo). In group A, no LTP was detected in 32 lesions, whereas in group B, LTP was detected in 4 of 29 tumors, which occurred at 2, 7, 9, and 15 mo after RFA. The frequency of LTP in group B (13.8%; 4/29) was significantly higher than that in group A (0/32, P = 0.046). All of the LTPs occurred in the area in which the 5 mm AM was not achieved. CONCLUSION The MRI-MRI image fusion using an ultrasound workstation is feasible and useful for evaluating the AM after RFA for HCC.

Immediate evaluation and guidance of liver cancer thermal ablation by three-dimensional ultrasound/contrast-enhanced ultrasound fusion imaging

Abstract Purpose: To investigate the feasibility and value of three-dimensional ultrasound/contrast-enhanced ultrasound (3D US-CEUS) fusion imaging for the immediate evaluation of technical success and the guidance of supplementary ablation during the liver cancer thermal ablation procedure. Materials and methods: Patients diagnosed with malignant liver cancer intending to receive thermal ablation including radiofrequency ablation (RFA) or microwave ablation (MWA) were enrolled. 3D US-CEUS fusion imaging was used to immediately assess the technical success and guide supplementary ablation. Contrast-enhanced computed tomography/magnetic resonance imaging (CECT/CEMRI) was performed one month after ablation to assess the technique effectiveness of the ablation. The registration success rate, duration time of 3D US-CEUS fusion imaging, technique effectiveness rate and major complications were recorded. Results: In total, 76 patients with 95 tumours who underwent RFA or MWA and assessed by 3D US-CEUS fusion imaging were enrolled. The registration success rate of 3D US-CEUS fusion imaging was 93.7% (89/95), and the duration time was 4.0 ± 1.1 min. Thirty lesions received supplementary ablation immediately during the procedure. The technique effectiveness rate of the ablation was 98.8% (81/82). There were no major complications related to ablation. Conclusions: 3D US-CEUS fusion imaging is a feasible and valuable technique for the immediate evaluation and guidance of supplementary ablation during the liver cancer thermal ablation procedure.

Contrast-Enhanced Ultrasonography Versus Contrast-Enhanced Computed Tomography for Assessment of Residual Tumor From Hepatocellular Carcinoma Treated With Transarterial Chemoembolization: A Meta-analysis: CEUS Versus CECT for Hepatocellular Carcinoma After TACE

This study reviewed the literature to directly evaluate the diagnostic performance of contrast‐enhanced ultrasonography (CEUS) versus contrast‐enhanced computed tomography (CECT) for assessing residual tumors of hepatocellular carcinoma treated with transarterial chemoembolization.

Computer-Assisted Hepatocellular Carcinoma Ablation Planning Based on 3-D Ultrasound Imaging

To evaluate computer-assisted hepatocellular carcinoma (HCC) ablation planning based on 3-D ultrasound, 3-D ultrasound images of 60 HCC lesions from 58 patients were obtained and transferred to a research toolkit. Compared with virtual manual ablation planning (MAP), virtual computer-assisted ablation planning (CAP) consumed less time and needle insertion numbers and exhibited a higher rate of complete tumor coverage and lower rate of critical structure injury. In MAP, junior operators used less time, but had more critical structure injury than senior operators. For large lesions, CAP performed better than MAP. For lesions near critical structures, CAP resulted in better outcomes than MAP. Compared with MAP, CAP based on 3-D ultrasound imaging was more effective and achieved a higher rate of complete tumor coverage and a lower rate of critical structure injury; it is especially useful for junior operators and with large lesions, and lesions near critical structures.

Double contrast-enhanced ultrasonography in the detection of periampullary cancer: Comparison with B-mode ultrasonography and MR imaging

PURPOSE To investigate the value of double contrast-enhanced ultrasonography (DCEUS) in the detection of periampullary cancer. MATERIALS AND METHODS Ninety-nine patients with surgery or biopsy-proven periampullary cancer who underwent both DCEUS and magnetic resonance imaging (MRI) examinations before operation were enrolled in our study. DCEUS in which intravenous microbubbles were used in combination with oral contrast agent and MRI were performed preoperatively to make a detection diagnosis of periampullary cancer. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of DCEUS, B-mode ultrasonography (BUS) and MRI were calculated and compared. Receiver operating characteristic (ROC) curves were used to evaluate the accuracy of BUS, DCEUS and MRI in the detection. Stratified analyses were performed for different pathological types and different sizes of periampullary lesions. The inter- and intra-observer reliability of DCEUS for cancer detection was also investigated. RESULT There were no significant differences in sensitivity, specificity, PPV, NPV or accuracy between DCEUS and MRI (all P>0.05). ROC analysis showed that the accuracy of DCEUS or MRI was higher than that of BUS (P<0.001), while no significant differences were noted in the accuracy between DCEUS and MR. In the 76 cases of periampullary cancer, DCEUS appeared to be superior to BUS for ampullary carcinoma, duodenum carcinoma and for lesions with an average diameter of less than 3cm. DCEUS appeared equal to BUS in other groups. No significant differences were noted between DCEUS and MRI in the stratified analysis. A considerably well agreement between DCEUS and MRI was obtained using Kappa analysis (k=0.649, P<0.001). The intra- and inter-observer reproducibility were both good for detection of periampullary cancer by DCEUS, with a Kappa values of 0.783 (P<0.01) and 0.732 (P<0.01), respectively. CONCLUSION DCEUS provides an available and useful imaging modality in the detection of periampullary cancer. This technique can aid in displaying the invisible periampullary region in BUS and may also become an effective supplemental method to MRI.

A clinical validation study for the feasibility and reliability of three-dimensional ultrasound-ultrasound automatic image registration

Abstract Purpose: The purpose of our study was to assess the feasibility and reliability of 3D ultrasound-ultrasound (US-US) automatic registration-based analysis of the hepatic vessel tree (VT) (3D VT-based automatic registration) in clinical applications. Materials and methods: A total of 70 pairs of 3D ultrasound data were acquired from the livers of 10 healthy volunteers enrolled in the study. An automatic registration method was applied to the acquired volumetric data pairs, and anatomic landmarks were picked by an experienced sonographer as ‘ground truth’. The influences of respiration phase, subject posture, and liver lobe on data acquisition and scan volumetric angle on the registration accuracy and robustness were investigated. The registration time, success rate, median registration error distance, and sonographer’s subjective feedback were assessed. Results: The time required for the 3D VT-based automatic registration was approximately 15∼20 s. Overall, the success rate for the hepatic vessel-based registration was 71% (50/70), and the median registration error distance was 1.72 mm (0.57∼4.71 mm). When the influential factors were well controlled, the optimal registration accuracy (median registration error distance = 1.22 mm) could be obtained with an excellent success rate of 100% (10/10). According to the subjective assessment of the sonographer, over 90% (45/50) of the automatic registration results were not inferior to the ground truth. Among them, 42% (21/50) were superior to the fusion results from the ground truth. Conclusions: The results suggest that the 3D VT-based automatic registration is feasible and reliable and has potential for guidance and evaluation of intraoperative ablation of hepatocellular carcinoma.

Selection of the most powerful predictors for the evaluation of hepatic steatosis grade: An experimental study

PURPOSE To select the most powerful predictors for the evaluation of hepatic steatosis grade. METHODS AND MATERIALS Forty-five healthy New Zealand rabbits were randomly divided into one normal control group and three experimental groups. Hepatic steatosis models were established by feeding a high-fat, high-sugar diet and drinking water containing 5% ethanol. Twenty-two variable indexes were measured using general observation, biochemical examination, ultrasonography, computed tomography (CT), and proton magnetic resonance spectroscopy (MRS). Univariate analysis, correlation analysis, and stepwise regression analysis were used to make the selection of the most powerful predictors. ROC analysis was used to compare the diagnostic efficacy of single index with combined index (Y) expressed by a regression equation. RESULTS Based on statistical analysis, there were 12 variable indexes with significant differences among groups, which correlated with hepatic steatosis grade: liver weight, hepatic index, liver CT value, liver-to-muscle attenuation ratio, 1H MRS fat peak value, fat peak area, fat-to-water peak area ratio, fat percentage, ultrasound attenuation coefficient, serum aspartate aminotransferase, total cholesterol (TC) and triglycerides. Among them hepatic index, liver CT value and serum TC were selected as the most powerful predictors for hepatic steatosis grade with correlation coefficients of 0.709, -0.764, and 0.886, respectively. The regression equation was: Y=1.975 + 3.906 x 10(-2)X1 + 0.369X2-2.84 x 10(-2)X3, where Y=hepatic steatosis grade, X1=TC, X2=hepatic index, and X3=liver CT value. ROC analysis displayed PPV, NPV, curve area of combined index (Y) were superior to simple index (hepatic index, liver CT value and serum TC) in evaluating hepatic steatosis grade, and they were nearly 1.0000, 1.0000 and 1.000, respectively. CONCLUSIONS Combined application of several diagnostic methods is superior to simple diagnostic method, and could provide comprehensive, rapid, accurate evaluation of hepatic steatosis grade.

Intracavitary Contrast-Enhanced Ultrasound in the Management of Post-Surgical Gastrointestinal Fistulas

The goal of this study was to investigate intracavitary contrast-enhanced ultrasound (IC-CEUS) measures in the management of post-surgical gastrointestinal (GI) fistula throughout detection, treatment and follow-up. From June 2010 to August 2016, patients who were administered ultrasound contrast agent (UCA) via a drainage tube for IC-CEUS were enrolled and retrospectively analyzed. They were suspected of having GI anastomotic fistulas or had been found to have fluid collections with ultrasound that were accompanied by abdominal pain or fever after surgical procedures. Forty-two patients met the inclusion criteria and were enrolled into this study. Twenty-two were confirmed to have GI fistulas confirmed by standard references. None were detected by conventional ultrasound. Although IC-CEUS successfully detected GI fistulas in 16 patients, it missed GI fistulas in 6 patients. One patient was misdiagnosed with a GI fistula. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the diagnosis of GI fistulas by IC-CEUS were 72.7% (16/22), 95.0% (19/20), 94.1% (16/17), 76.0% (19/25) and 83.3% (35/42), respectively. Twenty peritoneal fluid collections in 14 patients were related to fistulas by IC-CEUS based on the distribution of ultrasound contrast agents. Additional drainage was performed in 14 fistula-related fluid collections. Eight GI fistulas were judged to be cured after IC-CEUS re-evaluation, and the drainage tubes were removed from these patients. In conclusion, IC-CEUS can greatly improve the ability to diagnose post-surgical GI fistulas and may also play an important role in interventional treatment and follow-up.

Potential application of ultrasound-guided thermal ablation in rare liver tumors

BACKGROUND With the advances of imaging techniques, the detection rate of rare liver tumor is increased. However, the therapeutic strategies of the rare liver tumors remain limited. METHODS We analyzed twelve pathologically confirmed rare liver tumors in 8 patients. All of the patients underwent ultrasound (US) guided biopsy and subsequent thermal ablation. The tumors were ablated according to the preoperative plans and monitored by real-time US. CT/MRI fused with contrast enhanced US (CEUS) or three-dimensional (3D) US-CEUS images were used to guide and assess the ablation zone more accurately during thermal ablation. The rate of technical efficacy was assessed based on the contrast-enhance CT/MRI (CECT/MRI) results one month after ablation. Local tumor progression (LTP), recurrence and complications were followed up and recorded. RESULTS Among these twelve nodules, nine were subject to US-guided thermal ablation, whereas the other three inconspicuous nodules were subject to CEUS-guided thermal ablation. Intra-procedure CT/MRI-CEUS or 3D US-CEUS fusion imaging assessments demonstrated that the ablation zone sufficiently covered the original tumor, and no immediate supplementary ablation was required. Additionally, no major complications were observed during the follow-up period. The postoperative CECT/MRI confirmed that the technique success rate was 100%. Within the surveillance period of 13 months, no LTP or recurrence was noted. CONCLUSIONS US-guided thermal ablation was feasible and safe for rare liver tumors. The use of fusion imaging technique might make US-guided thermal ablation as effective as surgical resection, and this technique might serve as a potential therapeutic modality for rare liver tumors in the future.