Zhengbiao Ji

Microwave Ablation: An Experimental Comparative Study on Internally Cooled Antenna versus Non-internally Cooled Antenna in Liver Models

RATIONAL AND OBJECTIVES Microwave ablation is an alternative therapy with high cost-effectiveness for liver malignancy. The authors designed this experiment to compare the effect of microwave ablation using a non-internally cooled (NIC) antenna with that using an internally cooled (IC) antenna in both an ex vivo and an in vivo liver models. MATERIALS AND METHODS Sixty-two microwave ablations were performed in ex vivo porcine and in vivo canine liver models (NIC antenna, 28 coagulations; IC antenna, 34 coagulations). Pair comparisons were executed in terms of the coagulation parameters, including short-axis diameter (SD), long-axis diameter (LD), and spherical ratio (SR, SD/LD). The distributions of tissue temperatures were compared in ex vivo ablation. During in vivo ablation, the temperatures of antenna shaft were measured and unintended tissue coagulation were observed and compared. RESULTS In both ex vivo and in vivo ablations, less charring areas were found around the IC antenna shaft. With a longer SD (P < .01) and a shorter LD (P < .01), the coagulations of IC antenna appeared to be more spherical than those of NIC antenna (P < .01). During ablations in vivo, the temperatures of NIC antennas shaft were up to 90 degrees C or even higher, which resulted in some unintended tissue coagulation, whereas the temperatures of IC antennas shaft were lower than 20 degrees C in all ablation processes without any unintended tissue coagulation (P < .01). CONCLUSION The IC antenna performed better than NIC antenna in microwave ablation for liver models and might be more suitable for therapy for liver malignancy in clinical practice.

A novel simple noninvasive index to predict renal transplant acute rejection by contrast-enhanced ultrasonography.

Purpose This study aimed to evaluate the application of quantitative contrast-enhanced ultrasonography (CEUS) in the assessment of renal allograft dysfunction and to establish a new noninvasive index to predict acute rejection (AR). Methods Fifty-seven renal transplant recipients were enrolled in this prospective study. Before renal allograft biopsy, CEUS examinations were performed. The biopsy results proved 23 cases of AR (AR group), 10 cases of acute tubular necrosis (ATN group), and 24 with normal evolution (stable group). Contrast-enhanced ultrasonography parameters including rising time (RT), time to peak (TTP), and the delta-time among regions of interest (&Dgr;RT and &Dgr;TTP) were analyzed. Results In the AR group, RT and TTP of interlobar artery and medulla (RTi, RTm, TTPi, and TTPm) as well as &Dgr;RT and &Dgr;TTP between medulla and cortex (&Dgr;RTm-c and &Dgr;TTPm-c) were significantly higher compared with those in the stable group. RTm and TTPm as well as &Dgr;RTm-c and &Dgr;TTPm-c were remarkably higher compared with those in the ATN group. &Dgr;RTm-c and estimated glomerular filtration rate (eGFR) were identified as independent predictors by multivariate analysis (P = 0.008 and P = 0.024). On the basis of the multivariate analysis results and area under the receiver operating characteristic curves of individual markers, we constructed a new simple index, P = −0.587 + 0.286 × &Dgr;RTm-c − 0.028 × eGFR; new index = eP/(1 + eP), to discriminate AR, which had better area under the receiver operating characteristic curves than eGFR or individual CEUS parameters. Conclusion Contrast-enhanced ultrasonography parameters are reliable markers for differentiating the perfusion status of transplanted kidneys. Furthermore, the new simple index can easily predict AR with a high degree of accuracy.

Value of contrast-enhanced sonography in the diagnosis of peripheral intrahepatic cholangiocarcinoma.

To illustrate contrast‐enhanced harmonic ultrasonography (CEUS) findings of peripheral intrahepatic cholangiocarcinoma (PICC) and to assess the usefulness of CEUS in the diagnosis of this disease.

Application of imaging fusion combining contrast‐enhanced ultrasound and magnetic resonance imaging in detection of hepatic cellular carcinomas undetectable by conventional ultrasound

The aim of this study is to explore the value of volume navigation image fusion‐assisted contrast‐enhanced ultrasound (CEUS) in detection for radiofrequency ablation guidance of hepatocellular carcinomas (HCCs), which were undetectable on conventional ultrasound.

Application of imaging fusion combining CEUS and MRI in detection of HCCs undetectable by conventional ultrasound

The aim of this study is to explore the value of volume navigation image fusion‐assisted contrast‐enhanced ultrasound (CEUS) in detection for radiofrequency ablation guidance of hepatocellular carcinomas (HCCs), which were undetectable on conventional ultrasound.

Evaluation of Liver Metastases Using Contrast-Enhanced Ultrasound: Enhancement Patterns and Influencing Factors

Background/Aims To evaluate the enhancement patterns of liver metastases and their influencing factors using dynamic contrast-enhanced ultrasound (CEUS). Methods A total of 240 patients (139 male and 101 female; 58.5±11.2 years of age) diagnosed with liver metastases in our hospital were enrolled in this study to evaluate tumor characteristics using CEUS. A comparison of enhancement patterns with tumor size and primary tumor type was performed using the chi-square test. The differences between quantitative variables were evaluated with the independent-sample t-test and one-way analysis of variance. Results The enhancement patterns of liver metastases on CEUS were categorized as diffuse homogeneous hyperenhancement (133/240, 55.4%), rim-like hyperenhancement (80/240, 33.3%), heterogeneous hyperenhancement (10/240, 4.2%), and isoenhancement (17/240, 7.1%). There were significant differences in the enhancement patterns during the arterial phase based on the nodule size (p=0.001). A total of 231 of the nodules showed complete washout during the portal phase, and 237 nodules were hypoenhanced during the delayed phase. The washout time was correlated with tumor vascularity, with a longer washout time observed in hypervascular metastases compared to hypovascular metastases (p=0.033). Conclusions Diffuse homogeneous hyperenhancement followed by rapid washout was the most common enhancement pattern of liver metastases on CEUS and was affected by the nodule size and tumor vascularity. Small metastases were prone to show diffuse homogeneous hyperenhancement. Hyper-vascular metastases showed a significantly longer washout time compared to hypovascular metastases.

Primary non-Hodgkin＇s lymphoma of the liver： sonographic and CT findings

BACKGROUND A preoperative diagnosis of primary hepatic lymphoma (PHL) can have profound therapeutic and prognostic implications. Because of the rarity of PHL, however, there are few reports on diagnostic imaging. We reviewed the clinical and radiologic findings of 29 patients with PHL, the largest series to date, to evaluate the diagnostic features of this disease. METHODS Clinical data and radiologic findings at presentation were retrospectively reviewed for 29 patients with pathologically confirmed PHL from January 2005 to June 2013. Imaging studies, including ultrasound (US) (n=29) and contrast-enhanced computed tomography (CECT) (n=24), were performed within 2 weeks before biopsy or surgery. RESULTS Among the 29 patients, 23 (79%) were positive for hepatitis B virus (HBV) and 26 (90%) had a significantly elevated level of serum lactate dehydrogenase (LDH). There were two distinct types of PHL on imaging: diffuse (n=5) and nodular (n=24). Homogeneous or heterogeneous hepatomegaly was the only sign for diffuse PHL on both US and CECT, without any definite hepatic mass. For the nodular type, 63% (15/24) of patients had solitary lesions and 38% (9/24) had multiple lesions. On US, seven patients displayed patchy distribution with an indistinct tumor margin and a rich color flow signal. CECT showed rim-like enhancement (n=3) and slightly homogeneous or heterogeneous enhancement (n=14) in the arterial phase and isoenhancement (n=5) and hypoenhancement (n=12) in the portal venous and late phases. Furthermore, in five patients, CT revealed that hepatic vessels passed through the lesions and were not displaced from the abnormal area or appreciably compressed. CONCLUSIONS The infiltration type of PHL was associated with the histologic subtype. Considered together with HBV positivity and elevated LDH, homogeneous or heterogeneous hepatomegaly may indicate diffuse PHL, whereas patchy distribution with a rich color flow signal on US or normal vessels extending through the lesion on CECT may be the diagnostic indicators of nodular PHL.

Contrast-Enhanced Ultrasound Guided Biopsy of Undetermined Abdominal Lesions: A Multidisciplinary Decision-Making Approach

Aim. To investigate the value of contrast-enhanced ultrasound (CEUS) guided biopsy of undetermined abdominal lesions in multidisciplinary treatment (MDT) decision-making approach. Methods. Between Jan 2012 and Dec 2015, 60 consecutive patients (male, 37; female, 23; mean age, 51.3 years ± 14.6) who presented with undetermined abdominal lesions were included. CEUS and core needle percutaneous biopsy was performed under real-time CEUS guidance in all lesions. Data were recorded and compared with conventional ultrasound (US) guidance group (n = 75). All CEUS findings and clinical data were evaluated in MDT. Results. CEUS enabled the delimitation of more (88.3% versus 41.3%) and larger (14.1 ± 10.7 mm versus 32.3 ± 18.5 mm) nonenhanced necrotic areas. More inner (20.0% versus 6.7%) and surrounding (18.3% versus 2.7%) major vessels were visualized and avoided during biopsies. CEUS-guided biopsy increased the diagnostic accuracy from 93.3% to 98.3%, with correct diagnosis in 57 of 60 lesions (95.0%). The therapeutic plan was influenced by CEUS guided biopsies findings in the majority of patients (98.3%). Conclusion. The combination of CEUS guided biopsy and MDT decision-making approach is useful in the diagnostic work-up and therapeutic management.