acute cholecystitis is a common clinical situation. Depending on the time of onset of the disease, the clinical course and patients conditions immediate surgical intervention or conservative therapy (fasting, antibiotics) might be the treatment of choice. Only when incarcerated stones are present in infundibulum of the gall bladder rapid surgical intervention is mandatory due to the high risk of gall bladder perforation. These incarcerated stones are often invisible with percutaneous ultrasound and so the clinical course is prolonged with an increased risk of gall bladder perforation.

ObjectivesOBJECTIVES: small liver tumors (max. diameter 2 cm/0,8 ”) can be a challenge for any clinician, especially when a histology is needed. CT-guidance for biopsy is often insufficient. Sonographic guidance can miss the tumor if it is isoechogenic compared to the surrounding liver tissue. Contrast-enhanced ultrasound can improve the visibility of small liver tumors and can help to gain sufficient material for histological examination.MethodsMethods: 38 patients with small liver tumors not exceeding 2 cm/0,8 inch in diameter where histological verification of the tumor was mandatory underwent liver biopsy. Only those patients were enrolled where a referring radiologist failed to gain a sufficient liver biopsy with CT-guidance and also a sufficient (e.g. no normal liver tissue) biopsy was gained with native sonographic guidance in two attempts. These patients were examined with a special setting: high-end ultrasound system equipped with a special contrast software, i.v. bolus administration of 1,5 ml contrast agent SonoVue (Bracco Sp.A., Milano, Italy). The biopsy was conducted under local anesthesia with permanent ultrasound guidance in the so-called portal phase or late phase after administration of the contrast agent (which is 40 sec. after i.v. injection up to three minutes after injection) using a high-speed biopsy device. All patients had given their informed consent concerning biopsy and contrast agent administration.ResultsResults: in 36 of 38 patients we gained sufficient biopsy material to make a clear histological statement with only one biopsy, the remaining two patients underwent re-biopsy (also with CEUS-guidance) and could be diagnosed correctly with this second step. The histological results were: liver metastases in 32 cases (26 colorectal carcinoma, 2 stomach carcinoma, 2 adenocarcinomas of the pancreas, 2 adenocarcinomas of unknown origin), 4 HCCs. The two remaining patients (re-biopsy) also had liver metastases from colorectal carcinomas.ConclusionsConclusion: contrast-enhanced ultrasound guided biopsy is an excellent tool to improve the sampling results in patients with very small liver tumors when a biopsy is needed to improve the clinical decision pathway. ObjectivesOBJECTIVES: small liver tumors (max. diameter 2 cm/0,8 ”) can be a challenge for any clinician, especially when a histology is needed. CT-guidance for biopsy is often insufficient. Sonographic guidance can miss the tumor if it is isoechogenic compared to the surrounding liver tissue. Contrast-enhanced ultrasound can improve the visibility of small liver tumors and can help to gain sufficient material for histological examination. OBJECTIVES: small liver tumors (max. diameter 2 cm/0,8 ”) can be a challenge for any clinician, especially when a histology is needed. CT-guidance for biopsy is often insufficient. Sonographic guidance can miss the tumor if it is isoechogenic compared to the surrounding liver tissue. Contrast-enhanced ultrasound can improve the visibility of small liver tumors and can help to gain sufficient material for histological examination. MethodsMethods: 38 patients with small liver tumors not exceeding 2 cm/0,8 inch in diameter where histological verification of the tumor was mandatory underwent liver biopsy. Only those patients were enrolled where a referring radiologist failed to gain a sufficient liver biopsy with CT-guidance and also a sufficient (e.g. no normal liver tissue) biopsy was gained with native sonographic guidance in two attempts. These patients were examined with a special setting: high-end ultrasound system equipped with a special contrast software, i.v. bolus administration of 1,5 ml contrast agent SonoVue (Bracco Sp.A., Milano, Italy). The biopsy was conducted under local anesthesia with permanent ultrasound guidance in the so-called portal phase or late phase after administration of the contrast agent (which is 40 sec. after i.v. injection up to three minutes after injection) using a high-speed biopsy device. All patients had given their informed consent concerning biopsy and contrast agent administration. Methods: 38 patients with small liver tumors not exceeding 2 cm/0,8 inch in diameter where histological verification of the tumor was mandatory underwent liver biopsy. Only those patients were enrolled where a referring radiologist failed to gain a sufficient liver biopsy with CT-guidance and also a sufficient (e.g. no normal liver tissue) biopsy was gained with native sonographic guidance in two attempts. These patients were examined with a special setting: high-end ultrasound system equipped with a special contrast software, i.v. bolus administration of 1,5 ml contrast agent SonoVue (Bracco Sp.A., Milano, Italy). The biopsy was conducted under local anesthesia with permanent ultrasound guidance in the so-called portal phase or late phase after administration of the contrast agent (which is 40 sec. after i.v. injection up to three minutes after injection) using a high-speed biopsy device. All patients had given their informed consent concerning biopsy and contrast agent administration. ResultsResults: in 36 of 38 patients we gained sufficient biopsy material to make a clear histological statement with only one biopsy, the remaining two patients underwent re-biopsy (also with CEUS-guidance) and could be diagnosed correctly with this second step. The histological results were: liver metastases in 32 cases (26 colorectal carcinoma, 2 stomach carcinoma, 2 adenocarcinomas of the pancreas, 2 adenocarcinomas of unknown origin), 4 HCCs. The two remaining patients (re-biopsy) also had liver metastases from colorectal carcinomas. Results: in 36 of 38 patients we gained sufficient biopsy material to make a clear histological statement with only one biopsy, the remaining two patients underwent re-biopsy (also with CEUS-guidance) and could be diagnosed correctly with this second step. The histological results were: liver metastases in 32 cases (26 colorectal carcinoma, 2 stomach carcinoma, 2 adenocarcinomas of the pancreas, 2 adenocarcinomas of unknown origin), 4 HCCs. The two remaining patients (re-biopsy) also had liver metastases from colorectal carcinomas. ConclusionsConclusion: contrast-enhanced ultrasound guided biopsy is an excellent tool to improve the sampling results in patients with very small liver tumors when a biopsy is needed to improve the clinical decision pathway. Conclusion: contrast-enhanced ultrasound guided biopsy is an excellent tool to improve the sampling results in patients with very small liver tumors when a biopsy is needed to improve the clinical decision pathway.

small solid, non-cystic pancreatic lesions are found more and more frequently with high resolution endoscopic ultrasound. Various attempts were made to determine the clinical benefit of endoscopic ultrasound in the differentiation of pancreatic tumors using color doppler techniques and echo-enhanced percutaneous ultrasound by our working group. In this small study we examined only patients with small solid lesions of the panceas (max. diameter 20 mm) using a special software tool with echo-enhanced endoscopic ultrasound (low-MI scanning, subtraction of the grayscale background, visualization of the perfusion pattern).

Ziel: Klärung der Problemsituationen der Kontrastmittelsonografie an einem großen multizentrischen Kollektiv.

Ziel: Klärung der Problemsituationen der Kontrastmittelsonografie an einem großen multizentrischen Kollektiv.

Ziel: Tumorspezifische Vaskularisationsmuster fokaler Leberläsionen in der Kontrastmittelsonografie sollten in ihrer Häufigkeit und diagnostischen Treffsicherheit bei B-Bild-morphologisch unklaren Leberraumforderungen überprüft werden.

Purpose: To evaluate the diagnostic benefit of contrast-enhanced Ultrasound for the differential diagnosis of liver tumors in clinical practice.Materials and Methods: From May 2004 to December 2006 1349 patients (male 677, female 672) with a hepatic tumor lacking a definite diagnosis based on B-mode Ultrasound and power Doppler Ultrasound were examined at 14 hospitals by contrast-enhanced Ultrasound using a standardized protocol (pulse/phase inversion imaging, mechanical index 0.4). The Tumor status was assessed based on the vascularity pattern and contrast enhancement seen in focal lesions during the arterial, portal, and late phase. The diagnosis established after contrast-enhanced ultrasound was compared to histology (>75% cases) or in some cases to CT or MRI.Results: The final diagnosis of hepatic tumors included 573 benign hepatic tumors (hemangiomas n=242, focal nodular hyperplasia n=170, hepatocellular adenoma n=19, other benign lesions n=142) and 755 malignant hepatic tumors (metastases n=383, hepatocellular carcinoma n=279, other malignant lesions n=93). The overall diagnostic accuracy of contrast-enhanced ultrasound in comparison to the correct final diagnosis based on the combined gold standard was 90.3%. Contrast-enhanced ultrasound was able to correctly assess 723/755 malignant lesions (sensitivity 95.8%) and 476/573 benign lesions (specificity 83.1%). The positive predictive value of contrast-enhanced ultrasound for the diagnosis of a malignant tumor was 95.4% and the negative predictive value of contrast-enhanced ultrasound was 95.7%.Conclusion: Contrast-enhanced ultrasound clearly improves the differential diagnosis of hepatic tumors and is very helpful in clinical practice when B-scan or power Doppler morphological criteria are missing (page 16).

Purpose: Sonographically-guided Radio-Frequency Tissue Ablation-applied with a percutaneously placed needle can be used for the palliative treatment of primary or secondary liver tumours. In vitro experiments were carried out to establish the relations of the coagulation zone to histologic findings and sonographic appearence. Method: Fresh bovine livers were obtained and radio-frequency was applied under ultrasound guidance. The coagulation zone was dissected and examined by determining its three-dimensional diameters (macroscopically) and the histologic appearance of the coagulation margin to the surrounding tissue. In our series of 50 experiments the application time ranged from 30 seconds to 10 minutes. Results: The coagulation zone increased with increasing application time in a way that can be described as a negative logarithmic function. The largest volume was 4 x 5 x 5 cm (length, width, depth) approximating 50 ml. It was no problem to judge the coagulation zone sonographically. The macroscopically and sonographically determined width and length correlated with coefficients of 0.90 and 0.96. Microscopically the coagulation necrosis showed sharply outlined margins without any vital cells. Conclusion: Radio-Frequency Tissue Ablation applied under sonographic guidance has certain features which seem to make it a promising method for the palliative treatment of primary and secondary tumours of the liver.

Objective Can sonographic measurements of the transit time of an echo enhancer from the hepatic artery to the hepatic vein discriminate between patients with and without liver metastases? Method The hepatic transit time (hepatic artery to hepatic vein delay) of an echo enhancer (Optison) was measured in pulse inversion mode on the basis of time intensity curves (TIC) in patients with gastrointestinal tumours with proven liver metastases and in patients without liver metastases. Results Sixty-four patients (46 males, 18 females, mean age 61 ± 13 years) were admitted to the study. Fourteen patients had metastatic growth in the liver with a primary tumour in situ (group A). Fourteen patients had liver metastases following primary tumour resection (group B). Twenty-eight patients had a known primary tumour but no liver metastases (group C), and eight patients had neither liver symptoms nor a primary tumour (group D). The mean hepatic transit time in patients with liver metastases was 6.6 ± 1.8 s in group A and 6.7 ± 1.7 s in group B, whereas in patients without liver metastases it was significantly longer; namely, 15.7 ± 4.4 s in group C and 15.0 ± 2.0 s in group D (P < 0.001). The transit times in all patients with liver metastases were ⩽ 10 s, while in all patients without metastases except for four the times were ⩾ 12 s and one of the four had already developed liver metastases on early follow-up. Conclusions Measurement of the hepatic transit time permits discrimination of patients with and without liver metastases.

Objective: The aim of this study was to assess the use of a new stabilised perfluorocarbon microbubble agent, SonoVue® (Bracco, Milan, Italy) in the evaluation of tumoral vascularity and lesional characterisation using non-linear imaging (NLI) modes. Methods: 98 patients with focal liver lesions were studied using ATL 5000 and Siemens Elegra scanners. NLI mode, fundamental B mode, and power Doppler (PD) imaging of the liver were performed at baseline. NLI imaging of the hepatic lesion was then carried out at low mechanical index (0.1–0.3) immediately after an intravenous administration of SonoVue® (dose: 2.4 ml) for the first 4 minutes. Biopsy or combined CT/MR, biochemical markers, and other clinical information were used as the standard of reference. Diagnosis was established on the basis of the tumour vascularity and pattern of enhancement in the vascular phase and degree of contrast uptake within the lesion relative to that of normal liver in the late phase. Comparison and correlation between the US and CT/MR enhancement findings were also performed. Diagnostic accuracy (percent agreement) and diagnostic performance of contrast-enhanced US in identifying the lesion as benign or malignant were analysed. Results: The rank correlation between contrast-enhanced US and CT/MR classifications of tumour vascularity was highly significant in both arterial phase (r=0.92, p<0.001) and portal phase (r=0.73, p<0.001). Of all the confirmed benign tumours, 83% were classified as indeterminate, 8% as probably benign, and 8% as almost definitely benign using baseline US. On contrast-enhanced US, 92% were classified as definitely benign and 8% as almost definitely benign. All haemangiomas (even those measuring less than 1.5 cm) showed significant progressive centripetal contrast uptake in the late phase. The improvement in diagnostic classification was highly significant for both malignant and benign tumours (p<0.0001, Wilcoxon). Conclusions: These results suggest that SonoVue® enhanced ultrasound with non-linear imaging modes can display lesional vascularity in real-time and may be useful in improving the characterization of focal liver tumours.

AIM:To compare detection rates for liver metastases for conventional ultrasound, US using tissue harmonic imaging (THI), echo-enhanced pulse inversion harmonic imaging using Optison and Levovist.METHOD:In 73 patients with histologically proven gastrointestinal tumors spiral CT (S-CT), conventional US, US in the THI-mode, echo-enhanced ultrasound in the portal venous phase (ECI Optison ) and in the liver specific late phase (ECI Levovist) were performed and reviewed by blinded readers.RESULTS:73 patients (25 female, 48 male, age 63 +/- 11) were included. S-CT detected 158 liver metastases. Conventional US detected 117, THI 119, ECI Optison 169 and ECI Levovist 166 liver metastases. Especially for small (< 2 cm) liver metastases and metastases near the diaphragm echo-enhanced ultrasound exceeded conventional US (p < 0.001). Between both echo enhancers there was no significant difference.CONCLUSION:Using echo enhancers increases the ultrasound detection rate significantly. Examination in the portalvenous phase using a second generation enhancer (Optison) is equal to a late-phase examination using Levovist.

PURPOSEThe majority of patients with hepatocellular carcinoma (HCC) cannot be treated with surgery. This study evaluated the treatment of patients with radiofrequency ablation (RFA) with use of needle applicators perfused with isotonic saline solution.MATERIALS AND METHODSTwenty patients with a maximum of three HCCs as large as 60 mm and a contraindication to partial liver resection or orthotopic liver transplantation were enrolled in the study. They were treated with ultrasound-guided RFA with use of perfused needle applicators and followed with sonography and computed tomography.RESULTSTwenty patients (14 men, six women) with a total of 29 HCCs were treated with RFA. In total, 56 RFA treatments were performed. Mean HCC size was 31 mm (range, 10-60 mm). Two cases of self-limiting bleeding requiring transfusion of blood products took place. Complete response (CR) was achieved in 85% of patients (17 of 20). Partial response occurred in three tumors 45 mm in diameter or larger. There was a total of six local recurrences in five patients (25% of patients, 21% of tumors). Six patients (30%) exhibited distant recurrence, two of whom also showed local recurrence. In three patients, repeat treatment led to renewed CR. After a median follow-up of 445 days (range, 114-1,071 days), 12 patients (71% of the 17 patients with initial CR) still showed CR. Twelve patients (60% of all patients, 71% of those with initial CR) survived. Three of the eight patients who died were free of viable tumor at the time of death.CONCLUSIONSRFA with use of perfused needle applicators shows promise as an effective method for treating inoperable HCC. The most frequent complication was bleeding.

PURPOSE To evaluate survival, metastases, tumor necrosis, and prediction of local recurrence after percutaneous ultrasonographically (US) guided radiofrequency (RF) thermal ablation with electrodes perfused continuously with isotonic saline. MATERIALS AND METHODS VX2 liver tumors were implanted in 31 rabbits according to a standardized protocol. After 21 days, 16 animals were treated percutaneously with RF ablation. Four animals died of complications related to anesthesia, and 12 animals were evaluated. All animals were followed for 110 days and monitored with computed tomography (CT) and US at 1, 7, and 30 days. A control group of 15 animals did not receive treatment. Autopsy was performed at the end of scheduled follow-up or immediately after death. For survival analysis, the Kaplan-Meier method was used; for nominal data, the Fisher exact test was used. RESULTS In comparison to controls, animals in the treatment group showed significantly prolonged survival (P <.001). Eight of 12 animals (67%) treated with RF ablation survived to 110 days, while none of the controls did so. Metastases developed in all controls (100%) and in eight of 12 treated animals (67%) (P =.001). In comparison with controls, animals that developed metastases despite treatment also showed significantly prolonged survival (P =.02). Local recurrence was observed in three of 12 animals (25%) in the treatment group. CT and US performed 1 week after treatment did not allow prediction of local recurrence. CONCLUSION RF ablation of liver tumors with perfused needle applicators prolongs survival in the VX2 rabbit liver tumor model, regardless of whether complete remission is achieved. In comparison with controls, RF ablation results in a lower frequency of metastases.

INTRODUCTION:The majority of patients with primary and secondary tumours of the liver cannot be treated curatively by surgery. The treatment of these patients with radio-frequency thermoablation using perfused needle applicators (wet electrodes) was evaluated in a feasibility study. METHOD:Patients with primary and secondary tumours of the liver and contraindications against surgery or LTX were included into the feasibility study. RFA was performed percutaneously under ultrasound guidance. The patients were followed up sonographically and by computed tomography. RESULTS:20 patients (9 male, 11 female) with 35 lesions were treated with RFA. 12 patients (22 tumour locations) suffered from HCC and 8 patients (13 tumour masses) had liver metastases (colorectal, breast, pancreas, carcinoid). The median age was 65.6 years (36 to 83 years). The median tumour size was 33.5 mm. 59 RFTA applications (1.7 applications per tumour mass) were performed. The mean duration of RFTA per patient was 16.2 minutes. During the procedure isotonic saline was injected at a mean flow rate of 6.63 ml/min. All patients received local anaesthesia. In 33 sessions an additional analgosedation was necessary (average dose 63.8 mg Pethidine and 1.4 mg Midazolam). In 2 cases a reduction of the haemoglobin level, occurred, necessitating a blood transfusion. 3/4 of the treated metastases could be eradicated completely. Within a median follow-up of 145 days no intrahepatic local recurrence but 4 distant metastases occurred. 2/3 of the treated HCC could initially be brought into complete remission (CR). After a median follow-up of 329 days 5 of the 8 initially successfully treated patients with HCC were still in complete remission. In 3 cases an intrahepatic local recurrence developed. CONCLUSION:RFA with wet electrodes is a safe, effective and inexpensive treatment for primary and secondary tumours of the liver, measuring less than 4 cm in diameter.

BACKGROUND AND AIMS:We compared contrast-enhanced power Doppler sonography (CEPD) and phase-inversion harmonic imaging (PIHI) in the assessment of liver lesion vascularity and characterization of focal liver lesions.MATERIALS AND METHODS:We examined 101 focal liver lesions by CEPD and PIHI using Optison as echo-enhancing agent. Amount and architecture of lesion vascularity and the kinetics of contrast enhancement in the lesions were analyzed. A tumor diagnosis was assessed after each examination.RESULTS:Analysis of tumor vascularity was not possible in 30 liver lesions (30%) due to motion or blooming artifacts by CEPD. Vascularity was detected in 61% of liver lesions by CEPD and in 95% by PIHI. PIHI identified significantly more tumor vascularity pattern (93%) than CEPD (57%). Specific lesion diagnosis based on PIHI led to correct results in 92% compared to 59% by CEPD.CONCLUSION:PIHI is highly efficient in detecting tumor vascularity and is superior to CEPD in characterizing focal liver lesions.

Objective: The aim of this study was to compare the accuracy of unenhanced versus SonoVueTM® enhanced ultrasonography in the characterisation of focal liver lesions.Methods: 127 patients with focal liver lesions were studied using top-of-range equipments with non-linear imaging facilities. Standardised baseline scans and SonoVue® enhanced US (dose: 2 × 2.4 ml and 1 × 4.8 ml) with optimised non-linear imaging modes were performed. On the basis of the tumour vascularity and pattern of enhancement in the vascular phase and degree of contrast uptake within the lesion relative to that of normal liver in the late phase, diagnosis was made as to whether the lesion was benign or malignant. SonoVue® enhanced diagnosis was compared with that of baseline using combined enhanced helical CT, MR, and/or histology as the reference standard.Results: Of the total of 134 lesions studied, 82 were malignant and 52 were benign on the basis of the reference standard. The sensitivity for correctly classifying malignant lesions for unenhanced US was 28% compared with 90% for SonoVue® enhanced US; the difference was highly significant (McNemar’s test: p<0.0001). The specificity for correctly classifying benign lesions for unenhanced US was 35% versus 81% for enhanced US; the difference was highly significant (McNemar’s test: p<0.0001). Of the 25 haemangiomas, diagnosis was correct for unenhanced US in 36% versus 84% for enhanced US with the characteristic display of peripheral nodular centripetal enhancement. Of the 13 FNHs, unenhanced US correctly diagnosed 31% whilst enhanced US was accurate in 77%.Conclusions: These results suggest that SonoVue® enhanced US with non-linear imaging modes is superior to unenhanced US in the characterization of focal liver tumours with significant reduction in the number of indeterminate diagnoses. Objective: The aim of this study was to compare the accuracy of unenhanced versus SonoVueTM® enhanced ultrasonography in the characterisation of focal liver lesions. Methods: 127 patients with focal liver lesions were studied using top-of-range equipments with non-linear imaging facilities. Standardised baseline scans and SonoVue® enhanced US (dose: 2 × 2.4 ml and 1 × 4.8 ml) with optimised non-linear imaging modes were performed. On the basis of the tumour vascularity and pattern of enhancement in the vascular phase and degree of contrast uptake within the lesion relative to that of normal liver in the late phase, diagnosis was made as to whether the lesion was benign or malignant. SonoVue® enhanced diagnosis was compared with that of baseline using combined enhanced helical CT, MR, and/or histology as the reference standard. Results: Of the total of 134 lesions studied, 82 were malignant and 52 were benign on the basis of the reference standard. The sensitivity for correctly classifying malignant lesions for unenhanced US was 28% compared with 90% for SonoVue® enhanced US; the difference was highly significant (McNemar’s test: p<0.0001). The specificity for correctly classifying benign lesions for unenhanced US was 35% versus 81% for enhanced US; the difference was highly significant (McNemar’s test: p<0.0001). Of the 25 haemangiomas, diagnosis was correct for unenhanced US in 36% versus 84% for enhanced US with the characteristic display of peripheral nodular centripetal enhancement. Of the 13 FNHs, unenhanced US correctly diagnosed 31% whilst enhanced US was accurate in 77%. Conclusions: These results suggest that SonoVue® enhanced US with non-linear imaging modes is superior to unenhanced US in the characterization of focal liver tumours with significant reduction in the number of indeterminate diagnoses.