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.

Evaluation of the diagnostic accuracy of CEUS in children with benign and malignant liver lesions and portal vein anomalies.

OBJECTIVE: Comparison of the diagnostic findings of MRI, CT and CEUS in children with benign and malignant and portal venous anomalies of the liver. MATERIALS/METHODS: Retrospective analysis of the diagnostic findings of CEUS, MRI and CT scans in 56 children (age 0-17 years) with a total of 60 benign and malignant liver lesions and anomalies of the portal vein/perfusion. All patients underwent CEUS using sulphur hexafluoride microbubbles and a multi-frequency probe (1-5 MHz, 6-9 MHz). Cine-loops were stored up to 3 minutes. MRI was performed in 38 lesions. CT was performed in 8 lesions. RESULTS: Out of the 56 patients 49 liver lesions (48 benign, 1 malignant), 9 anomalies of the portal vein/perfusion and 2 of the biliary system were detected. 16/49 lesions were analyzed histopathologically. Using CEUS, the characterization of the lesions was possible in 45 out of 49 cases. In 32 cases, CEUS provided the exact diagnosis. Only two benign lesions were falsely categorized as malignant.Findings of MRI and CEUS were concordant in 84% of cases (n = 32/38). CEUS considered 1 benign lesion to be malignant. 2 lesions were not detectable and in 3 lesions no definite diagnosis was established using MRI.Findings of CT and CEUS were concordant in 5 of 8 cases. In 21 lesions CEUS as the only imaging modality was found to be sufficient for diagnostics. CONCLUSION: Despite the restricted indications for using CEUS in children, it offers a high diagnostic detection rate (93%) for characterization of liver lesions and portal vein anomalies.

Contrast-enhanced ultrasound for differential diagnosis of suspected GvHD in patients after allogeneic transplantation.

GvHD is a serious complication in patients after allo-SCT, presenting with unspecific symptoms such as abdominal pain or cramps and diarrhea. Early diagnosis of GvHD, after differentiation from other causes leading to the same symptoms, such as viral or bacterial enteritis, is highly important because the time needed for diagnosing GvHD is directly correlated to a worsening of the outcome. We examined 23 patients presenting with the abdominal symptoms mentioned above, of whom 20 had received an allo-SCT in their history and were thus potential candidates for enteric GvHD. The other three patients were included because they also presented with abdominal symptoms similar to those of GvHD, which could be ruled out due to their history. We wanted to evaluate CEUS in these patients as an additional subgroup to gain more data on the value of CEUS in early detection of enteral GvHD and in the differentiation of GvHD against other causes of abdominal discomfort. All patients underwent CEUS with particular attention to penetration of the intravenously applied microbubbles in the bowel lumen. In the patients having allo-SCT in their history we strove to achieve histological confirmation of GvHD of the GI-tract. The resulting examinations were documented digitally. Out of 17 patients with confirmed GvHD of the GI tract, 14 showed penetration of the intravenously applied microbubbles into the bowel lumen, leading to a sensitivity and specificity of 82% and 100% for transmural bubble penetration for GvHD of the GI-Tract, since the patients without GvHD of the GI tract showed no transmural bubble penetration. In patients with viral or bacterial infections of the GI tract, no transmural penetration of the microbubbles into the bowel lumen was observed. For microbubble penetration as a criterion for GvHD of the GI-Tract, this leads to a negative predictive value (NPV) of 67%, and a positive predicative value (PPV) of 100%.