Post-mortem distribution of Iodinated Contrast Media (ICM) (iodixanol versus iopromide) in the porcine kidney after multiple bolus injections in vivo into the supra-renal aorta1.

 Iodinated contrast media (ICM) are widely used for diagnostic and interventional procedures in radiology and cardiology. Ideally, they should not interact with blood cells or vascular wall cells to avoid deteriorations of the blood circulation. However, it is well known that ICM can affect erythrocytes as well as endothelial cells which consequently might perturb especially the microcirculation. In former studies the influence of two ICM (iodixanol versus iopromide) on the vascular system, the development of blood stasis, on changes in renal resistive index (RRI) and vascular diameters, and on the post-mortem distribution of iodine as marker for ICM in the explanted kidneys was examined. The modus of ICM application into the supra-renal aorta followed the regime in interventional cardiology, so that 10 bolus injections were administered at steady intervals (iopromide 4,32 ml / iodixanol 5 ml) accompanied by infusion of 500 ml isotonic NaCl-solution.In the present study, the post-mortem X-ray analysis revealed that there were no differences in iodine content in the regions of the mid-cortex and the medullo-pelvic transition zone of the kidneys after application of both ICM. Remarkable differences, however, were found in the region of the capsule-near cortex, where the application of iopromide led to a significantly lower iodine content in the microcirculation. This is in good agreement with former studies, in which a maldistribution in this area, presumably due to a decrease in arteriolar inflow as a result of stasis/occlusion was shown.

Incidence and evolution of venous thrombosis during the first 3 months after irreversible electroporation of malignant hepatic tumours.

The incidence and evolution of venous thrombosis adjacent to the ablation zone after percutaneous irreversible electroporation (IRE) were evaluated to identify potential risk factors in patients with hepatic malignancies. 205 venous structures (in 87 patients) within a ≤1.0 cm radius of the ablation zone were assessed after IRE of 112 hepatic lesions (74 primary, 38 secondary hepatic malignancies) by pre-interventional and post-interventional (1-3 days, 6 weeks and 3 months after IRE) contrast-enhanced magnetic resonance imaging. The relationships between venous thrombosis and clinical features were analysed using a binary logistic regression model. In 27 of 87 patients (31%), a total of 67 venous complications were noted during the 3 months follow-up. Thrombosis represented the most frequently observed complication (n = 47; 70.1%), followed by vessel narrowing (n = 20; 29.9%). 5 (10.6%) of 47 thromboses showed spontaneous regression 3 months after IRE. A small vessel diameter (p = 0.011) and post-interventional vessel narrowing (p = 0.006) were independently associated with delayed post-ablative thrombosis. Delayed venous thrombosis frequently occurs after IRE of hepatic malignancies. Pre-existing vessel narrowing and a small vessel diameter represent significant risk factors that require further surveillance and potentially therapeutic intervention.

Influence of hepatic fibrosis and inflammation: Correlation between histopathological changes and Gd-EOB-DTPA-enhanced MR imaging.

OBJECTIVE: To evaluate the influence of an active inflammatory process in the liver on Gd-EOB-DTPA-enhanced MR imaging in patients with different degrees of fibrosis/cirrhosis. MATERIAL AND METHODS: Overall, a number of 91 patients (61 men and 30 women; mean age 58 years) were included in this retrospective study. The inclusion criteria for this study were Gd-EOB-DTPA-enhanced MRI of the liver and histopathological evaluation of fibrotic and inflammatory changes. T1-weighted VIBE sequences of the liver with fat suppression were evaluated to determine the relative signal change (RE) between native and hepatobiliary phase (20min). In simple and multiple linear regression analyses, the influence of liver fibrosis/cirrhosis (Ishak score) and the histopathological degree of hepatitis (Modified Hepatic Activity Index, mHAI) on RE were evaluated. RESULTS: RE decreased significantly with increasing liver fibrosis/cirrhosis (p < 0.001) and inflammation (mHAI, p = 0.004). In particular, a correlation between RE and periportal or periseptal boundary zone hepatitis (moth feeding necrosis, mHAI A, p = 0.001) and portal inflammation (mHAI D, p < 0.001) was observed. In multiple linear regression analysis, both the degree of inflammation and the degree of fibrosis were significant predictors for RE (p < 0.01). CONCLUSION: The results of this study suggest that the MR-based hepatic enhancement index RE is not only influenced by the degree of fibrosis, but also by the degree of inflammation.

Percutaneous irreversible electroporation of hepatocellular carcinoma: Contrast-enhanced ultrasound-findings during 1-year follow-up.

PURPOSE: To assess the postprocedure findings after percutaneous irreversible electroporation (IRE) of hepatocellular carcinoma (HCC) in contrast-enhanced ultrasound (CEUS). MATERIALS AND METHODS: Percutaneous IRE was performed in a total of 22 patients with 24 HCC tumours following interdisciplinary tumour board review. The lesions were documented using CEUS before, immediately and within 24 hours after IRE. During follow-up CEUS was performed at 6 weeks and 3, 9, and 12 months after ablation. Two experienced radiologists evaluated the acquired CEUS image date in a consensus reading. RESULTS: Median tumour size before treatment was 13.7±4.8 mm (short axis) and 16.0±5.2 mm (long axis). All HCC lesions showed arterial hyperenhancement in CEUS. Median size of the ablation defect after ablation was 29.3±5.2 mm (short axis) and 31.6±5.6 mm (long axis). After IRE all tumours showed complete devascularization. The size of the ablation defects showed significant shrinkage and reduced peripheral enhancement in the course of follow-up. At 12 months follow-up the ablation defect size decreased to 16.7±4.3 mm (short axis) and 18.3±4.1 mm (long axis). CONCLUSION: CEUS showed a complete devascularization of HCC tumours after IRE. Post-intervetional peripheral enhancement returned to normal during follow-up and may represent zones of reversible damage of cellular integrity through electroporation. A significant shrinkage of the ablation defects during 12 month of follow-up was seen in all cases.

Evaluation of integrated color-coded perfusion analysis for contrast-enhanced ultrasound (CEUS) after percutaneous interventions for malignant liver lesions: First results.

BACKGROUND:  With the rising number of percutaneous ablation therapies in malignant liver lesions there is a need of reliable diagnostics after the intervention to differentiate between reactive changes and tumor. PURPOSE: To assess the success of percutaneous ablation therapies for malignant liver lesions using CEUS with perfusion analysis. MATERIAL AND METHODS: Retrospective analysis of perfusion analysis for 67 patients with 94 malignant liver lesions, treated with ablation therapies. The lesions were 70 hepatocellular carcinomas (HCC), 18 metastases, 4 cholangiocellular carcinomas (CCC), 2 lesions remained unclear. CEUS was performed after bolus injection of 1.6-2.4 ml of sulfur-hexafluoride microbubbles. The perfusion analysis was calculated using Peak, TTP, mTT and AUC with integrated software during the late arterial to early portal-venous phase for approximately 9 sec (5-15 sec). For the evaluation of the success after percutaneous treatment the perfusion results were compared to the follow-up control after 6 months with CT and MRI and CEUS. RESULTS: Perfusion analyses after percutaneous treatment of malignant liver lesions showed highly significant perfusion differences when comparing the center to the surrounding tissue and the margins (p<0.0001) for Peak and also for AUC. 62 lesions were successfully treated, meaning there was no local recurrence after 6 months. In cases of residual tumor CEUS showed a nodular marginal enhancement, the corresponding perfusion analyses showed nodular red and yellow pseudo-color shades. CONCLUSIONS: Using CEUS and perfusion analysis, a critical analysis of post-ablation defects in malignant liver lesions is possible. With the help of pseudo-colors, remaining tumor-vascularization can be detected.

Stereotactically navigated percutaneous microwave ablation (MWA) compared to conventional MWA: a matched pair analysis.

PURPOSE: To compare CT-navigated stereotactic microwave ablation (SMWA) to non-navigated conventional MWA (CMWA) for percutaneous ablation of liver malignancies. METHODS: A matched pair analysis of 36 patients who underwent MWA of primary or secondary liver malignancies (10 hepatocellular carcinoma and 8 metastases) was conducted. A total of 18 patients undergoing SMWA were included in this prospective study. Patients were matched in terms of tumor size, liver segment and entity to retrospective CMWA procedures. The endpoints were procedure time, accuracy of needle placement, technical success rate, complication rate and dose-length product (DLP). RESULTS: The procedure durations were 23.9 min (SD 3.7) for CMWA and 21.8 min (SD 16.3) for SMWA (p = 0.22). The procedural accuracy for SMWA and CMWA was identical for both groups (3.7 mm). The total DLP was significantly lower for SMWA than for CMWA (2115 mGy cm (SD 276) vs. 3109 mGy cm (SD 1137), respectively; p < 0.01). Complete ablation without residual tumor was observed in 94% (17 of 18) of SMWA and in 83% (15 of 18) of CMWA patients (p = 0.31). No complications occurred. CONCLUSIONS: SMWA is highly accurate and reduces the radiation dose without increasing the procedure time.

Evaluation of dynamic effects of therapy-induced changes in microcirculation after percutaneous treatment of vascular malformations using contrast-enhanced ultrasound (CEUS) and time intensity curve (TIC) analyses.

The aim of this follow-up study was to demonstrate the effect of percutaneous interventional treatment on local microcirculation of peripheral vascular malformations using CEUS and TIC analysis. MATERIAL AND METHODS: Retrospective analysis of 197 patients (136 female; 61 male; 3-86 years) with 135 venous (VM), 39 arterio-venous (AVM), 8 lymphatic and 15 veno-lymphatic peripheral vascular malformations before and after the first percutaneous treatment.CEUS was performed after i.v. injection of 1-2.4 ml of sulfur hexafluoride microbubbles (SonoVue®) using a 6-9 MHz linear probe. Digitally stored cine loops (starting in the early arterial phase for 60 sec) were read by independent readers in consensus. Regions of interest (ROI) were defined in the center and at the margins of the malformation, as well as in the healthy surrounding tissue. TIC analyses with Time to Peak (TTP) and Area under the Curve (AUC) were calculated using integrated perfusion software. RESULTS: After the treatment there was a significant decrease for median AUC in VM in the center from 297.8 (14.5-2167.6) rU down to 243.3 (0.1-1678.8) rU (p = 0.043) and in the surrounding tissue down to 107.7 (20.2-660.2) rU (p = 0.018). For the other malformations AUC decreased in the center and the margins as well. TTP rose, however these changes did not reach the level of significance. CONCLUSION: Analyzing the capillary microcirculation TICs offer a possibility of monitoring therapy-induced capillary changes of vascular malformations.

Reduced microperfusion due to portal vein thrombosis: Impact on the outcome of percutaneous thermal tumor ablation.

PURPOSE: To determine the influence of pre-interventionally existing portal vein thrombosis on the ablation success of percutaneous tumor ablation of HCC. MATERIALS AND METHODS: 15 patients with HCC and pre-existing portal vein thrombosis underwent thermal tumor ablation. We retrospectively analyzed the pre- and post-interventionally performed CT and MRI scans in terms of technical success as well as the complication rate. The portal vein thrombosis was classified into segmental, lobar and central thrombus. RESULTS: In 13/15 cases (87%) complete ablation with no evidence of residual tumor tissue was seen 6 weeks after the procedure in contrast-enhanced MRI scans and contrast-enhanced ultrasound (CEUS). No major and 2 minor complications were observed after the ablation procedure. CONCLUSION: Reduced perfusion due to pre-interventionally existing portal vein thrombosis has no significant impact on the ablation success or the complication rate.

Quantitative evaluation of real-time maximum liver capacity (LiMAx) and time intensity curve (TIC) analysis in CEUS-based microperfusion.

PURPOSE: To compare the diagnostic performance of real-time maximum liver capacity (LiMAx) with dynamic contrast-enhanced ultrasound (CEUS)-based liver microcirculation. MATERIALS AND METHODS: 23 patients underwent liver function capacity (LiMAx) test and consecutive or previous CEUS examinations. A bolus injection of 1.4 ml sulfur hexafluoride microbubbles was administered for CEUS measurements (1-6 MHz) and quantitative perfusion analysis (TIC) was performed with an integrated perfusion software using stored cine-loops. Two perfusion-parameters, time to peak (TtoP) and area under the curve (Area), were evaluated in liver parenchyma and portal vein using TIC analysis.To compare quantification parameters, patients were classified in patients representing a healthy population (LiMAx value >315 µg/kg/h) and those representing patients with liver disease (LiMAx value <315 µg/kg/h). RESULTS: Comparing perfusion parameters derived from portal vein measurements, TtoP and Area were higher in patients with normal liver function TtoP: 25.0±8.4 s, Area: 1483±920 a.u. compared to patients with impaired liver function TtoP: 22.4±14.0 s; Area 1351±1212 a.u. This difference however was not statistically significant (p = 0.52, p = 0.48).In parameters derived from measurements in liver parenchyma TtoP was higher (38.5±11.3 s) and Area was lower (999±632 a.u.) in patients with normal liver function compared to patients with impaired liver function (TtoP; 30.6±11.0 s, p = 0.156; Area: 1202±719 a.u.) (p = 0.16, p = 0.56).In a simple linear regression model, none of the perfusion parameters measured in portal vein (TtoP portal, Area portal) and liver parenchyma (TtoP liver, Area liver) correlated significantly with respective LiMAx values (p = 0.194-0.950). CONCLUSION: Within the framework of this study, CEUS-based perfusion parameters were not able to assess severity of liver disease, assessed with LiMAx- test.

Effect of irreversible electroporation of prostate cancer on microcirculation: Imaging findings in contrast-enhanced T1-weighted 3D MRI.

OBJECTIVES: Irreversible electroporation (IRE) is a novel focal ablation technique applicable for treatment of prostate cancer (PCa). We aim to evaluate imaging findings of T1-weighted contrast-enhanced MRI after percutaneous IRE of low-risk PCa. METHODS: A total of 13 male patients underwent IRE of focal low-risk PCa and were included in this analysis. Prostate IRE was conducted using 2-4 electrodes being placed under CT-fluoroscopy guidance. Dynamic contrast-enhanced 3D isotropic fat-saturated T1-weighted MRI (DCE-MRI) was performed 24-72 hours before and 24-72 hours after ablation. RESULTS: Ablated prostate was either homogeneously (8/13 [62%]) or heterogeneously (5/13 [38%]) hypo attenuating. Peripheral contrast enhancement manifesting as a hyper attenuating margin was observed during the arterial (60 sec) (3/13 [23%]) and venous (240 sec) (10/13 [77%]) phase. The ablation defect showed a sharp (8/13 [62%]) or blurry (5/13 [38%]) margin. CONCLUSIONS: The results show a venous peripheral rim enhancement in most of the cases, indicating reactive hyperaemia. The heterogeneous appearance of the defect zone in some cases may be secondary to sustained vascularization.

Comparison of computed tomography (CT) and contrast-enhanced ultrasound (CEUS) for the quantitative evaluation of an ablation defect following radiofrequency ablation of malignant liver lesions.

OBJECTIVE: To compare contrast-enhanced computed tomography (CT) and contrast-enhanced ultrasound (CEUS) for the quantitative evaluation of an ablation defect following radiofrequency ablation of malignant liver lesions in a prospective study. MATERIALS AND METHODS: 22 radiofrequency ablations of malignant liver tumors were performed. The ablation defects were then measured and evaluated by two independent examiners via contrast-enhanced computed tomography (CT) and contrast-enhanced ultrasound (CEUS) using a 1-5 MHz multifrequency convex ultrasound transducer (LOGIQ E9, GE) with respect to the short-axis diameter, the long-axis diameter, and the area. RESULTS: Quantitative evaluation of ablation defects is possible with both contrast-enhanced CT and CEUS. The average long-axis diameter was 47.1 mm (±11.08;±23,5%) on CEUS and 56.48 mm (±14.14;±25,0%) on CT; the short-axis diameter was 39.72 mm (±11.14;±28,05%) on CEUS and 40.27 mm (±10.50;±26,07%) on CT; the area was 1439.82 mm2 (±678.57;±47,13%) on CEUS and 2392.68 mm2 (1147.67;±48,0%) on CT. On average, ablation defects are assessed to be larger on CT than on CEUS. A significant correlation between the modalities could not be achieved for all measurement axes. CONCLUSION: CEUS can be used for the postinterventional detection and evaluation of ablation defects. However, these are always assessed to be larger on contrast-enhanced CT than CEUS.

Low Tube Voltage Liver MDCT with Sinogram-Affirmed Iterative Reconstructions for the Detection of Hepatocellular Carcinoma.

Aim of this study was to compare low tube voltage computed tomography (80 kV) of the liver using iterative image reconstruction (SAFIRE) with standard computed tomography (120 kV) using filtered back-projection (FBP) for the detection of hepatocellular carcinoma (HCC). 46 patients (43 men) with 93 HCC confirmed by 3 T MRI with Gd-EOB-DPTA, in inconclusive cases combined with contrast-enhanced ultrasound, underwent dual-energy CT. The raw data of the 80 kV tube was reconstructed using the iterative reconstruction algorithm SAFIRE with two strengths (I3 and I5). The virtual 120 kV image data set was reconstructed using FBP. The CT images were reviewed to determine the lesion-to-liver contrast (LLC), the lesion contrast-to-noise ratio (CNR) and the sensitivity. The LLC (57.1/54.3 [I3/I5] vs. 34.9 [FBP]; p ≤ 0.01), CNR (3.67/4.45 [I3/I5] vs. 2.48 [FBP]; p < 0.01) and sensitivity (91.4%/88.2% [I3/I5] vs. 72.0% [FBP]; p ≤ 0.01) were significantly higher in the low-voltage protocol using SAFIRE. Therefore, low tube voltage CT using SAFIRE results in an increased lesion-to-liver contrast as well as an improved lesion contrast-to-noise ratio compared to FBP at 120 kV which results in a higher sensitivity for the detection of HCC.

Planning and guidance: New tools to enhance the human skills in interventional oncology.

Navigation systems have the potential to achieve a high accuracy for percutaneous ablation of tumors even for those in difficult locations. In the last years, successful research has been conducted to make navigation devices applicable to percutaneous tumor ablation with special planning software that now allows high accuracy even for deep-located small lesions close to critical structures. Because of the high number of available navigation systems, this review focuses on those with preexisting clinical studies.

Efficiency of contrast enhanced ultrasound for immediate assessment of ablation status after intraoperative radiofrequency ablation of hepatic malignancies.

AIM: To evaluate the efficiency of intraoperative contrast enhanced ultrasound (Io-CEUS) for assessment of radiofrequency ablation (RFA) during liver tumor surgery. MATERIAL AND METHODS: Retrospective analysis was performed on a total number of 18 patients out of over 500 patients who underwent combined liver tumor surgery and RFA of 27 hepatic tumors between 02/2011 and 12/2016. Io-CEUS was performed by bolus injections of up to 10 ml sulphur hexaflourid microbubbles for diagnostic purposes. To guide the RFA up to 20 ml microbubbles were applied to monitor the procedure and assess the ablation status finally. A fully avascular area or absence of any residual vascularization intratumorally was considered technical success. These findings were correlated to findings of follow-up imaging results (CEUS, MRI, CT) at least 1 up to 40 months (mean 11 months) after surgery. RESULTS: 13 male and 5 female patients aged between 45-77 years (mean 59.2±17.1 years) with 26 malignant and one most probable benign hepatic lesion were treated with intraoperative RFA. Io-CEUS detected 23 preoperatively unknown liver lesions leading to a change in therapy in 13/18 cases (72,2%). All 27 treated lesions showed an avascular area immediately after RFA. According to follow-up imaging results (1 month - 3 years after surgery, mean follow-up time 11 months), 2/18 patients had local recurrences, 8 patients had distant intrahepatic recurrences or extrahepatic recurrence, 8 patients remained tumor-free. Thereby, a success rate of CEUS guided RFA of 89% could be obtained concerning the targeted liver lesions. CONCLUSION: Modern intraoperative ultrasound using B-mode and Io-CEUS is a valuable tool for optimization of diagnostic and therapeutic intraoperative liver procedures and ablative therapies.

[Irreversible electroporation (IRE) : A minimally invasive therapeutic option in prostate cancer]. / Irreversible Elektroporation (IRE) : Eine minimal-invasive Methode zur Therapie des Prostatakarzinoms.

CLINICAL PROBLEM: Prostate cancer is one of the most common malignant diseases in older men. As such, screening and early detection are of crucial importance. STANDARD TREATMENT: The standard management of prostate cancer includes radical prostatectomy, radiation therapy, or hormonal therapy. These standard therapies yield excellent oncologic results, but also produce significant side effects. In cases of low-risk prostate cancer, these therapies might result in over-treatment; for this reason, active surveillance has been introduced. However, acceptance of this strategy varies between patients. TREATMENT INNOVATIONS: Irreversible electroporation is a novel non-thermal ablation technique for soft tissues. The ablation mechanism of irreversible electroporation has some theoretical advantages in the treatment of prostate cancer. It allows image-guided focal treatment of malignant prostate tissue and a potential sparing of adjacent structures, thereby theoretically resulting in a marked reduction in treatment-related side effects compared with standard management. PRACTICAL RECOMMENDATIONS: Although irreversible electroporation is a promising ablation technique, it should only be used in the context of clinical trials to treat prostate cancer due to the current lack of solid evidence for this new technology.

Contrast-enhanced ultrasound (CEUS) in an interdisciplinary intensive care unit (ICU): Diagnostic efficacy in the assessment of post-operative complications compared to contrast-enhanced computed tomography (CECT): First results.

To evaluate the effectiveness of high-resolution contrast-enhanced ultrasound (CEUS) to diagnose early post-operative complications in an interdisciplinary intensive care unit.In 50 patients (male 32; female 18) 64 CEUS examinations were performed in an intensive care unit (ICU) setting to detect post-operative complications. Multi-frequency transducer (1-5 and/or 6-9 MHz) were used. All 64 examinations were performed by one experienced examiner. CEUS findings were compared with contrast-enhanced computed tomography (CECT) findings. CECT images were acquired within 1-24 hours after CEUS examination in arterial and portal-venous phases of the abdomen using either a 16-slice computed tomography scanner or a 128-dual slice computed tomography scanner.In 56 out of 64 cases (88%) the CEUS-based diagnosis corresponded with the CECT diagnosis. Vascular stenosis in hepatic arteries and portal veins were recognised in both imaging modalities but were evaluated differently [5 cases]. In 3 cases (5%) small peripheral splenic infarction, retroperitoneal hematoma and fluid collection around the liver were not diagnosed by CEUS. CONCLUSION: CEUS in an ICU setting enables a reliable detection of postoperative abdominal complications as compared to CECT.

Percutaneous Irreversible Electroporation: Long-term survival analysis of 71 patients with inoperable malignant hepatic tumors.

Aim of this retrospective analysis was to evaluate the survival times after percutaneous irreversible electroporation (IRE) in inoperable liver tumors not amenable to thermal ablation. 71 patients (14 females, 57 males, median age 63.5 ± 10.8 years) with 103 liver tumors were treated in 83 interventions using IRE (NanoKnife® system). The median tumor short-axis diameter was 1.9 cm (minimum 0.4 cm, maximum 4.5 cm). 35 patients had primary liver tumors and 36 patients had liver metastases. The Kaplan-Meier method was employed to calculate the survival rates, and the different groups were compared using multivariate log-rank and Wilcoxon tests. The overall median survival time was 26.3 months; the median survival of patients with primary land secondary liver cancer did not significantly differ (26.8 vs. 19.9 months; p = 0.41). Patients with a tumor diameter >3 cm (p < 0.001) or more than 2 lesions (p < 0.005) died significantly earlier than patients with smaller or fewer tumors. Patients with hepatocellular carcinoma and Child-Pugh class B or C cirrhosis died significantly earlier than patients with Child-Pugh class A (p < 0.05). Patients with very early stage HCC survived significantly longer than patients with early stage HCC with a median survival of 22.3 vs. 13.7 months (p < 0.05).

Evaluation of a robotic system for irreversible electroporation (IRE) of malignant liver tumors: initial results.

OBJECTIVE: Comparison of conventional CT-guided manual irreversible electroporation (IRE) of malignant liver tumors and a robot-assisted approach regarding procedural accuracy, intervention time, dose, complications, and treatment success. METHODS: A retrospective single-center analysis of 40 cases of irreversible electroporation of malignant liver tumors in 35 patients (6 females, 29 males, average age 60.3 years). Nineteen of these ablation procedures were performed manually and 21 with robotic assistance. A follow-up (ultrasound, CT, and MRI) was performed after 6 weeks in all patients. RESULTS: The time from the planning CT scan to the start of the ablation as well as the dose-length product were significantly lower under robotic assistance (63.5 vs. 87.4 min, [Formula: see text]; 2132 vs. 4714 mGy cm, [Formula: see text]). The procedural accuracy, measured as the deviation of the IRE probes with respect to a defined reference probe, was significantly higher using robotic guidance (2.2 vs. 3.1 mm, [Formula: see text]). There were no complications. There was one incomplete ablation in the manual group. CONCLUSION: Robotic assistance for IRE of liver tumors allows for faster procedure times with higher accuracy while reducing radiation dose as compared to the manual placement of IRE probes.

Microwave ablation of large HCC lesions: Added value of CEUS examinations for ablation success control.

PURPOSE: To assess the value of dynamic contrast enhanced ultrasound (CEUS) for the detection of residual tumor tissue day 1 after microwave ablation (MWA) of large hepatocellular carcinoma (HCC) compared to MRI. MATERIAL AND METHODS: 30 consecutive patients (5 females, 25 males, mean age 64 years, age range 54-73 years) with an untreated HCC lesion larger than or equal to 3 cm underwent percutaneous MWA between 03/2014 and 04/2016. 1 patient was excluded because of an artificial pacemaker. All remaining 29 patients underwent 3-T MRI with liver-specific contrast agent and CEUS 1 day after ablation to detect residual tumor tissue. The 6-week follow-up including CEUS and MRI was defined as the reference standard. RESULTS: Complete ablation was achieved in 23 of 29 treated lesions (79%). The sensitivities and specificities for the detection of residual tumor tissue on day 1 were 100% and 83% for CEUS and 87% and 67% for MRI resp. without the differences being statistically significant. CONCLUSION: CEUS allows a reliable assessment of therapeutic success of percutaneous ablation of large HCC lesions one day after the ablation. Its ability to visualize reactive periablation perfusion changes in real-time might be of advantage in the depiction of residual tumor tissue when compared to MRI imaging alone.