Dynamic endoluminal contrast enhanced ultrasound (CEUS) for display of drainages in inflammatory abdominal fluid collections1.

AIM: To evaluate the additive clinical value of endoluminal contrast enhanced ultrasound (CEUS) after interventional placement of drainages in abdominal fluid collections. MATERIAL/METHOD: Examination of 30 patients using a 1-6 MHz convex probe (Resona 7, Mindray) to locate the fluid collection in B-Mode. Additionally, dynamic endoluminal CEUS with 1 ml sulphur-hexafluoride microbubbles was performed to measure the extent of the percutaneously drained abscesses. Independent assessment of dynamically stored images in PACS in DICOM format. Correlation to reference imaging using computed tomography (CT). RESULTS: A total of 30 patients were examined (17 m, 19-78 years, mean 56.1 years). Drainages were positioned in the liver in 15 cases, in the pelvis after kidney transplantation in 4 cases, close to the spleen in 1 case, and in the abdomen in 10 cases. In all cases abscesses showed marginal hyperaemia with reactive septations in CEUS. The drainage position was assessed by means of B-mode in all cases first and then by CEUS. In 4 cases CEUS showed a fistula to the pleura, in 5 cases to the peritoneum, in 2 cases to the intestine, in 5 cases to the biliary tract, corresponding to the CT. In 2 cases there was a hint of an anastomotic leakage after intestinal anastomosis, which was reliably detected by CT. The drainage was removed in 11 cases within a period of 2 to 5 days after CEUS control, in 9 cases within a period of 5 to 10 days. Another operation was necessary in 3 cases. A new drainage was placed in 2 cases. The required amount of ultrasound contrast medium is 1 ml endoluminally diluted to 9 ml sodium chloride. CONCLUSION: CEUS facilitates the exact localization and characterization of inflammatory abdominal fluid collections. Furthermore, possible fistulas can be detected that cannot be seen with conventional ultrasound.

High-performance sonographical multimodal imaging of non cystic thyroid lesions: Chances of the preoperative diagnostics in relation to histopathology.

AIM: To improve preoperative diagnostics of solid non-cystic thyroid lesions by using new high-performance ultrasound techniques: optimized B-mode morphology, elastography, Color-Coded Doppler-Sonography (CCDS) and contrast enhanced ultrasound (CEUS)MATERIALS AND METHODS:In 33 cases solid, non-cystic thyroid lesions were rated as TIRADS 3 and up from conventional B-mode examinations. Additional high resolution Power Doppler including HR- and Glazing-Flow as optimized macrovascularization techniques, shear wave elastography and CEUS were performed on these patients by one experienced examiner. For CEUS a bolus of 1-2.4 ml Sulfurhexafluorid microbubbles (SonoVue®, Bracco, Milan, Italy) was injected into a cubital vein and then the distribution kinetics of the contrast agent were documented from the early arterial phase (10 to 15 seconds after injection) to the late venous phase (5 minutes after injection). Postoperative histopathology was the diagnostic gold standard as it provides the most reliable proof. RESULTS: 33 patients (13 males, 20 females; age 29 -77 years; mean 55 years; SD 13 years) were included in this study. 28 of them had benign regressive thyroid nodules, 3 had adenomas and 4 were diagnosed with carcinomas (3 were histologically identified as papillary thyroid carcinomas, one as a medullary thyroid carcinoma). The volume of the thyroid gland ranged from 6.6 to 401.3 cm2 (mean 72.6±92.0 cm2).The adenoma diameters ranged from 9 to 40 mm (mean 22±16 mm) and the carcinoma diameters ranged from 19 to 33 mm (mean 26±6 mm). The 3 adenomas had different echogenicities: One was completely echofree, one was hypoechoic and one isoechoic. The 4 carcinomas however were equally characterized as hypoechoic and echofree. Two of three adenomas and all of the carcinomas showed an incomplete or diffuse margin. Micro-calcifications were found in one adenoma and in every carcinoma. However, no micro-calcifications were observed in cases of benign regressive nodules.Performing shear-wave elastography the adenomas showed lower values than the carcinomas: The tissue velocity of the adenomas ranged from 2.86 m/s to 3.85 m/s (mean 3.32±0.5 m/s) and in carcinomas from 3.89 m/s to 5.66 m/s (mean 4.18±0.3 m/s).Marginal hypervascularization was detected in two adenomas after applying CCDS. One adenoma was hypovascularized. The four carcinomas showed an irregular extreme hypervascularization along their margins as well as an irregular central normo- or hypervascularization in CCDS. The additional HR-Flow helped reducing artefacts.In CEUS the dynamic capillary microvascularization of all carcinomas was very irregular with early enhancement and followed by partial or complete wash-out. In CEUS two adenomas had no wash-out and the other one showed a partial wash-out. CONCLUSION: Using modern multimodal imaging offers new possibilities for the differentiation between benign and malignant thyroid lesions. It is a very important diagnostic tool in addition to the B-Mode TIRADS classification and eases the decision between TIRADS 3, 4 and 5. However, additional multicenter studies are required for more detailed evaluations.

Diagnostic performance of ultrasound strain elastography for differentiation of malignant breast lesions.

OBJECTIVE: Objective of the study was to assess the performance of ultrasound strain elastography combined with conventional B-mode ultrasound to diagnose suspicious breast lesions (BI-RADS 4 and 5). METHODS: Between January 2015 and December 2017, a total of 86 patients (55±17.9 years) with solid or unclear, non-cystic breast lesions were enrolled in the study. The breast lesions were evaluated by B-mode ultrasound and subsequent ultrasound strain elastography. Ultrasound features including echo pattern, lesion shape, marginal characteristics, calcifications, orientation and posterior features are useful for differentiating benign breast lesions from malignant ones. Malignant ultrasound features are irregular shape, hypoechoic pattern, spiculated margin, nonparallel orientation and posterior shadowing. Lesions with benign features such a circumscribed margin were classified as low conspicuous. In patients with highly conspicuous malignant masses ultrasound-guided core needle biopsy or surgical excision was performed. RESULTS: Among the 86 patients, 60 masses were histologically proven and 36 of these were malignant. Of the malignant lesions 26 invasive carcinomas were of no special type (NST), 1 invasive lobular carcinoma, 3 ductal carcinomas in situ and 6 metastases. 20 of these patients had breast density classified as ACR 3 or 4. The mean size of the masses was 1.2 cm (range: 0.5-5 cm). Based on ultrasound B-mode imaging, the lesions were classified as BI-RADS category 4 (n = 20; three 4a, nine 4b and eight 4c) and BI-RADS category 5 (n = 16). One patient had to be reclassified after strain elastographxy to BI-RADS 3.The sensitivity of ultrasound with strain elastography and additional B-Mode ultrasound for the characterization of solid breast lesions was 97%, for conventional B-mode alone 92%; the respective specificities were 82% and 73%, respectively. CONCLUSION: Ultrasound elastography can be a supplementary approach to conventional ultrasound to improve the diagnostic accuracy of malignant breast lesions.

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.

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.

Interventional Removal of Intravascular Medical Devices: Methods and Technical Success.

PURPOSE: Evaluation of the technical success rate and complications when retrieving dislocated intravascular foreign bodies. MATERIAL AND METHODS: Between 1999 and 2015 38 patients (21 female; 17 male; Age: 17 - 92; Average 54.3 years) underwent an extraction of intravascular dislocated foreign bodies, which were not lost during a radiological intervention. The extracted material included 29 port catheters, 3 tips of tunneled dialysis catheters, 2 stents, 2 guide wires, 1 CVC tip and 1 AS occluder device. Various catheters for repositioning and extraction were used. The access was transarterial as well as transvenous. Technical success was defined as complete removal of the foreign body. RESULTS: The technical success rate was 92.1 % (35 of 38). In 17 patients an additional catheter was necessary to reposition the foreign body in order to make it accessible for the extraction catheter. In one case a stent was relocated and remodeled within the patient and was not extracted. In another case we experienced a dislocation of a small fragment of the port catheter into the distal parts of the pulmonary artery, which couldn't be extracted. A guide wire could not be extracted as it was already adhered with the vessel wall. Peri-interventional complications were not documented. CONCLUSION: The percutaneous extraction of dislocated intravascular foreign bodies is technically successful and poor of complications. Interventional therapy can avoid surgical removal. KEY POINTS: • The percutaneous extraction of dislocated intravascular foreign bodies is technically successful and safe.• In most cases surgical removal can be avoided.• The gooseneck-snare catheter was mainly used for the extraction of intravascular foreign bodies. Citation Format: • Ayx I, Goessmann H, Hubauer H et al. Interventional Removal of Intravascular Medical Devices: Methods and Technical Success. Fortschr Röntgenstr 2016; 188: 566 - 573.

Analysis of arterial dynamic micro-vascularization with contrast-enhanced ultrasound (CEUS) in thyroid lesions using external perfusion software: First results.

AIM: To determine different perfusion characteristics of histo-pathologically proven adenomas and carcinomas of the thyroid gland with CEUS and perfusion software. MATERIAL AND METHODS: Retrospective perfusion analysis of 25 patients with carcinomas and 41 cases of adenomas of the thyroid gland (30 males, 36 females; aged 18 - 85 years, mean 56 years). All cases were histologically analyzed. Perfusion analysis was independently performed using external perfusion software (VueBox®). TTP, mTT, Peak and Rise time were calculated. RESULTS: Lesions' sizes ranged from 0.2 to 10.2 cm in carcinomas (mean 2.18 cm), and from 0.6 to 5.0 cm in adenomas (mean 2.25 cm). In 20 out of 25 carcinomas that were evaluated with CEUS, a complete wash-out in the late venous phase was found. Adenomas showed wash-out at the border.Perfusion analysis in VueBox® revealed some parameters which tend to show differences between adenomas and carcinomas, however did not reach the level of significance.Median Peak in carcinomas was highest at the margins (2945 rU), and lowest in the surroundings (1110 rU). Mean Transit Time (mTT) values showed no differences between center, margin and surrounding.In adenomas healthy tissue showed higher mTT values compared to the center (24.6 vs. 20.7 sec). Median Peak was highest in the surrounding tissue and lowest in the margins (1999 vs. 1129 rU). No statistical differences could be found in the comparisons. CONCLUSION: CEUS with perfusion analysis offers new possibilities for the dynamic evaluation of micro-vascularization in thyroid adenomas and carcinomas. Using VueBox® the perfusion analysis of the arterial phase provides new parameters that help determine a lesion's malignancy or benignity. However a final assessment regarding malignancy and benignity of thyroid lesions using only CEUS and perfusion analysis of the arterial phase is not yet possible.

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.

Chronic liver disease: Quantitative MRI vs CEUS-based microperfusion.

PURPOSE: To compare the diagnostic performance of MRI-based T1 relaxometry with dynamic contrast-enhanced ultrasound (CEUS)-based liver microcirculation for evaluation of liver function. MATERIALS AND METHODS: 22 patients underwent Gd-EOB-DTPA-enhanced MRI with T1 relaxometry and previous or consecutive CEUS examinations. A transverse 3D VIBE sequence with an inline T1 calculation was acquired and the reduction rate of T1 relaxation time (rrT1) was evaluated. For CEUS measurements (1-6 MHz), a bolus injection of 1.4 ml sulfur hexafluoride microbubbles were administered and both cine loops and single images from arterial phase up to late phase were stored.Quantification of time to peak (TTP), rise time (RT), Wash- In Area Under the Curve (WiAUC), mean transit time (mTTI), the wash- in rate (WiR) and Wash-in perfusion index (WIPI)) was performed using a novel quantification software (VueBoxTM). To compare quantification parameters, patients were classified in patients representing a healthy population (rrT1 > 50%, n = 8) and those representing patients with liver disease (rrT1 < 50%, n = 14). RESULTS: Comparing perfusion parameters TTP, mTTI, and WiR were higher in patients without liver disease compared to patients with impaired liver function (p = 0.10-0.21). RT, WiAUC and WIPI were significantly lower in patients with impaired liver function (RT, 14.8±1.5 s; WiAUC, 17288±6179 a.u., WIPI, 1243±423) compared to patients without liver disease (RT, 21.2±2.6 s, p = 0.032; WiAUC, 71534±25600, p = 0.034; WIPI, 4286±1748, p = 0.04). In a simple linear regression model, none of the perfusion parameters correlated significantly with rrT1 (p = 0.08-0.63). CONCLUSION: Within the framework of this study, CEUS-based perfusion parameters were not able to assess severity of liver disease, however, WiAUC, RT and WIPI were significant perfusion parameters to make a rough assessment of liver function.

Intrasurgical dignity assessment of hepatic tumors using semi-quantitative strain elastography and contrast-enhanced ultrasound for optimisation of liver tumor surgery.

OBJECTIVE: To evaluate the efficacy of strain elastography (SE) using semi-quantitative measurement methods compared to constrast enhanced ultrasound during liver tumor surgery (Io-CEUS) for dignity assessment of focal liver lesions(FLL). MATERIAL AND METHODS: Prospective data acquisition and retrospective analysis of US data of 100 patients (116 lesions) who underwent liver tumor surgery between 10/2010 and 03/2016. Retrospective reading of SE color patterns was performed establishing groups depending on dominant color (>50% blue = stiff, inhomogenous, >50% yellow/red/green = soft tissue). Semi-quantitative analysis was performed by Q-analysis based on a scale from 0 (soft) to 6 (stiff). 2 ROIs were placed centrally, 5 ROIs in the lesion's surrounding tissue. Io-CEUS was performed by bolus injection of 5-10 ml sulphurhexaflourid microbubbles evaluating wash-in- and -out- kinetics in arterial, portal venous and late phase. Histopathology after surgical resection served as goldstandard. RESULTS: 100 patients (m: 65, f: 35, mean age 60.5 years) with 116 liver lesions were included. Lesion's size ranged from 0.5 to 8.4 cm (mean 2.42 cm SD±1.44 cm). Postoperative histology showed 105 malignant and 11 benign lesions. Semi-quantitative analysis showed central indurations of >2.5 in 76/105 cases suggesting malignancy. 7 benign lesions displayed no central indurations correctly characterized benign by SE. ROC-analysis and Youden index showed a sensitivity of 72.4% and specificity of 63.6% assuming a cut-off of 2.5. Io-CEUS correctly characterized 103/105 as malignant. Sensitivity was 98%, specificity 72.7%. CONCLUSION: Strain elastography is a valuable tool for non-invasive characterization of FLLs. Semi-quantitative intratumoral stiffness values of >2.5 suggested malignancy. However, sensitivity of Io-CEUS in detecting malignant lesions was higher compared to SE. In conclusion SE should be considered for routine use during intraoperative US in addition to Io-CEUS for optimization of curative liver surgery.

Perfusion quantification of vascular malformations using contrast-enhanced ultrasound (CEUS) with time intensity curve analysis before and after treatment: First results.

AIM: Aim of this pilot-study was to quantify perfusion changes of vascular malformations before and after the first interventional treatment using contrast-enhanced ultrasound (CEUS). MATERIAL AND METHODS: 29 patients (10 male, 19 female) between 6 and 63 years (mean 28.1 years) with 12 arterio-venous (AVM) and 17 venous malformations (VM) were examined before and after their first percutaneous interventional treatment. CEUS was performed with a 2.4 ml bolus injection of sulfur-hexafluorid microbubbles, and a 6-9 MHz mulitfrequency transducer. A 60 sec cine sequence was recorded and regions of interest (10 mm×30 mm) were defined in the centre, and the margins of the vascular malformation as well as in the surrounding healthy tissue. Time Intensity Curves (TIC) were analysed, and Time to Peak (TTP) as well as Area under the Curve (AUC) were calculated. RESULTS: For VM there was a significant perfusion difference (p < 0.05) in AUC between centre and the surrounding tissue before (323.1 vs. 130.4 rU) and after treatment (331.0 vs. 106.9 rU). There was no significant difference for TTP in ROIs of VM (19.1 vs. 26.5 sec). After the treatment there was a significant decrease in AUC for all three regions in AVMs, and an increase in TTP for AVM. However TTP for AVM in the centre ROI still remained shorter than in the surrounding tissue even after therapy (20.9 vs. 25.4 sec). CONCLUSION: CEUS with TIC analysis is a promising imaging method for the evaluation of perfusion before and after percutaneous treatment of vascular malformations. AUC decrease indicates therapy-induced changes in perfusion of VM whereas an increase in TTP shows therapy-related changes in AVM.