First assessment of flow phenomena of acute and chronic thrombosis in the jugular veins using new ultrasound vector-flow imaging

AIM

First assessment of flow changes in the jugular veins using high resolution ultrasound vector flow.

MATERIAL UND METHODS

15 patients (8 males, 7 females) with an age range of 35 to 82 years (mean age 58.53±12.26 years) were examined by an experienced examiner using high power ultrasound equipment (Resona R9, Mindray) with probe technology (Mindray L9-3U Linear Array transducer, 2.5 to 9.0 MHz). This group was compared with five healthy subjects (mean age 35.4±13.79 years) as a reference. To assess flow changes, the color-coded duplex sonography and the novel vector flow technique were used. The evaluation was performed of vector morphology changes, turbulence, and wall resistance measurements.

RESULTS

There were changes after acute and chronic thrombosis in 9 cases, and venous compression in 7 cases. Turbulence was measurable from 0.01 % to 64.44 %, the average turbulence was 19.73±22.06 %. Wall resistance measurement showed values from 0.01 Pa to 3.14 Pa, depending on the age of the thrombosis or compression. The reference veins showed turbulence of 0.94±1.5 % and a mean wall resistance of 0.05±0.05 Pa. There are statistically significant differences between normal and thrombotic or compressed veins in terms of maximum wall stress (p = 0.006) and mean degree of turbulence (p = 0.012), while the difference in mean wall stress is not statistically significant (p = 0.058).

CONCLUSION

Despite still existing technical limitations, the combination of V-flow and wall stress measurements in jugular vein changes suggests a high diagnostic potential.

Advanced multimodal imaging of solid thyroid lesions with artificial intelligence-optimized B-mode, elastography, and contrast-enhanced ultrasonography parametric and with perfusion imaging: Initial results

 Goal of the study was the assessment of AI-assisted diagnosis of solid thyroid foci with multimodal modern ultrasound imaging. 50 patients (26-81 years, 54.7±13.1 years) were included in the study. Multimodal ultrasound imaging by means of B-mode with linear probe (4-12 MHz) with option of automated documentation of findings by means of AI, with supplementary Ultra MicroAngiography (UMA) was used. Macrovascularisation was assessed by dynamic contrast ultrasonography (CEUS) with parametric evaluation and perfusion analysis, and microvascularization was assessed by combined strain and shear wave elastography on a novel high-performance ultrasound system (Resono R9/Mindray) by an experienced examiner with independent reading. The evaluation was performed according to TI-RADS III-V.The volume of the thyroid lobes on both sides averaged 39 ml±5 ml (27 to 69 ml). The 13 cases of histologically confirmed thyroid carcinomas (8 papillary, 2 medullary, 2 microfollicular, 1 anaplastic CA) with a mean size of 15 mm±6 mm (9-21 mm) were correctly evaluated by TI-RADS V on the basis of irregular shape, induration >  2.5 m or >  30kPA and striking wash-out kinetics. Tumor lymph nodes could only be correctly detected preoperatively in one case of medullary carcinoma according to the surgical findings, based on irregular vascularization with UMA in roundish shape with cortex >  4 mm, transverse diameter up to 11 mm. In 25 cases of inhomogeneous nodular goiter an evaluation with TI-RADS III was performed in 31 cases, in 4 cases with incomplete marginal contour, partial marginal vascularization with UMA and partial wash out with indurations up to 2.5 m/s 30 kPA an evaluation with TI-RADS IV and surgical excision for nodular goiter. In 12 cases regressive nodular changes without relevant malignancy criteria resulted in nodular goiter, with focal changes up to 1.5 cm in diameter, classified as requiring control with TI-RADS III. There were no relevant changes in findings in the controls after 6 months. From the AI tool, the 20/25 goiter nodes were assessed as TI-RADS III, 7/12 adenomas, 5 goiter nodes, and 5 adenomas as TI-RADS IV, 5/13 carcinomas as TI-RADS IV, and 8/13 carcinomas as TI-RADS V.Multimodal ultrasound diagnostics supported by AI has a high diagnostic potential for the evaluation of solid thyroid lesions and standardizes the reporting with digital representative image documentation. CEUS perfusion and modern elastography techniques allow targeted follow-up of TI-RADS III findings.

Current aspects of multimodal ultrasound liver diagnostics using contrast-enhanced ultrasonography (CEUS), fat evaluation, fibrosis assessment, and perfusion analysis - An update

Current ultrasound multifrequency probes allow both improved detail resolution and depth of penetration when examining the liver. Also, new developments in vascular diagnostics, elastography with fibrosis assessment, evaluation of possible steatosis, and parametric and time intensity curve (TIC) analysis of dynamic microvascularization of the liver with contrast-enhanced ultrasound sonography (CEUS) complement ultrasound-guided diagnostics. State-of-the-art high-resolution technology includes a high frame rate (HiFR) mode for CEUS, fast shear wave measurements with the sound touch quantify (STQ) mode, artifact-free flow detection using HR flow and glazing flow in combination with a special flow-adapted imaging (Ultra Micro Angiography, UMA) and additionally different assessments of possible fatty liver (UltraSound ATtenuation Imaging Technology, USAT). In 50 cases with focal liver lesions, a multimodal liver diagnosis was performed with a still new high-performance ultrasound system as part of the clarification of questions from the university liver consultation and tumor outpatient clinic.

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.

Multimodal ultrasound imaging with conventional B-mode, elastography, and parametric analysis of contrast-enhanced ultrasound (CEUS): A novel approach to assess small bowel manifestation in severe COVID-19 disease

The aim was to describe the small bowel morphology with conventional B-mode and elastography and additionally to evaluate dynamic effects of COVID-19 associated small bowel microvascularization using CEUS with color coded perfusion parameters.Thirteen patients with severe COVID-19 acute respiratory distress syndrome (ARDS) were investigated. 13 patients required intensive care treatment with mechanical ventilation. Five patients required extracorporeal membrane oxygenation (ECMO). Contrast-enhanced ultrasound (CEUS) was performed by an experienced investigator as a bolus injection of up to 2.4 ml sulfur hexafluoride microbubbles via a central venous catheter. In the parametric analysis of CEUS, the flare of microbubbles over time is visualized with colors. This is the first work using parametric analysis of CEUS to detect perfusion differences in the small bowel.Parametric analysis of CEUS in the intestinal phase was carried out, using DICOM loops for 20 seconds. In 5 patients, parametric analysis revealed intraindividual differences in contrast agent behavior in the small bowel region. Analogous to the computed tomography (CT) images parametric analysis showed regions of simultaneous hyper- and hypoperfusion of the small intestine in a subgroup of patients. In 5 patients, the parametric image of transmural global contrast enhancement was visualized.Our results using CEUS to investigate small bowel affection in COVID-19 suggest that in severe COVID-19 ARDS systemic inflammation and concomitant micro embolisms may lead to disruption of the epithelial barrier of the small intestine.This is the first study using parametric analysis of CEUS to evaluate the extent of small bowel involvement in severe COVID-19 disease and to detect microemboli. In summary, we show that in COVID-19 the small bowel may also be an important interaction site. This is in line with the fact that enterocytes have been shown to a plenitude of angiotensin converting enzyme (ACE)-2 receptors as entry sites of the virus.

Contrast enhanced ultrasonography (CEUS) a novel tool to detect intestinal epithelial barrier dysfunction in severe COVID-19 disease

Ten patients with confirmed COVID-19 disease were studied. Nine patients required intensive care treatment, among them four needed extracorporeal membrane oxygenation (ECMO). Contrast enhanced ultrasonography (CEUS) was performed by one experienced investigator as a bolus injection of up to 2.4 ml of sulphur hexafluoride microbubbles via a central venous catheter. B-Mode evaluation and strain elastography showed mural edema of the small bowel with a thickness of up to 10 mm in all patients. We applied color coded Doppler sonography (CCDS) and power mode with flow-adapted parameters and early, dynamic capillary arterial contrast enhancement of bowel wall structures <10 s to assess perfusion of the small bowel. In all patients, reactive hyperemia was seen in the entire small bowel. In a subgroup of seven patients microbubbles translocated into the intestinal lumen. Thus, high-grade intestinal barrier disruption secondary to SARSCoV-2 infection can be postulated in these patients. This is the first description of perfusion changes and a disruption of the small bowel epithelial barrier in COVID-19 Patients using contrast ultrasonography and elastography.

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 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.

Surface imaging of breast implants using modern high-frequency ultrasound technology in comparison to high-end sonography with power analyses for B-scan optimization1

AIM

This study aims to evaluate optimized breast implant surface-structure analysis by comparing high-end ultrasound technology with a new high frequency technique. This comparative study used new breast implants with different surfaces in an in vitro setting.

METHODS

Nine idle silicon or polyurethane (PU) breast implants were examined by two investigators in an experimental in vitro study using two high-end ultrasound devices with multi-frequency transducers (6-15 MHz, 9-16 MHz, 12.5-33 MHz).The ultrasound B-Mode was optimized using tissue harmonic imaging (THI), speckle reduction imaging (SRI, level 0-5), cross beam (high, medium, low) and photopic.Using a standardized ultrasound protocol, the implants were examined in the middle (point of highest projection) and lateral, by two independent examiners.Image evaluation was performed on anonymized digital images in the PACS. The aim was to achieve an artifact-free recording of the surface structure, the surface coating, the total image structures and, as far as possible, an artifact-free internal representation of the implants.For independent surface evaluation a score was used (0 = undetectability of surface structures, rich in artifacts, 5 = best possible, artifact free image quality).

RESULTS

The quality of ultrasound imaging of breast implant surfaces after the optimization of B-Scan differed significantly comparing high-end ultrasound technology with modern high-frequency ultrasound technology (p < 0,05).The following setting has been found to be the best setting with the highest image quality:B-Mode, SRI value 3, Crossbeam high level with color coded imaging for B- mode. In the total examined frequency range of 6-33 MHz, the highest image quality was found in the average frequency range of 12.5-33 MHz at both measured points. For both devices, device 1 (high-end) and device 2 (high frequency) ultrasound, the image quality was in the12.5-33 MHz frequency range with an average image quality of 3.236. It was significantly higher, than in the lower frequency ranges and the same frequency range with THI. (p < 0,05).  The image quality of the high-end sonography device was superior to the conventional high-frequency ultrasound device in all frequency ranges.

CONCLUSION

High-end ultrasound imaging technology was superior in the quality of implant surface evaluation in comparison to high-frequency ultrasound sonography. The gained knowledge can serve as a basis for further multicenter clinical application and studies with the aim to develop an objective, precise tool to evaluate the implant and the surrounding tissue with ultrasound.

High resolution flow (HR Flow) and glazing flow in cases of hepatic flow changes: Comparison to color-coded Doppler sonography (CCDS)

AIM

To evaluate the possibilities of flow detection using high resolution flow (HR Flow) and Glazing Flow technique in patients with liver parenchymal changes and flow changes in comparison to colour coded Doppler sonography (CCDS).

MATERIAL AND METHODS

All examinations were performed using a multi frequency matrix convex probe with high resolution technique (SC6-1U/Resona7, Mindray, Shenzhen, China) by one experienced examiner to evaluate the venous, portal venous and arterial liver flow with digital documentation of the dynamic flow parameters like peak systolic flow, end-diastolic flow and resistance index. For liver parenchymal stiffness changes shear wave elastography was performed with at least 10 measurements. By two independent readers an elevation was performed to evaluate the image quality and the degree of flow artefacts, from 0 = not available to 5 points with excellent image quality without flow artefacts.

RESULTS

All 40 patients (24 men, 16 women, age 27-83 years, mean 56±5 years) showed morphology changes from B-Mode of the liver parenchyma to inhomogeneous tissue with higher stiffness evaluated by the shear wave elastography (1.45 m/s up to 2.79 m/s±1.79 m/s, considering F1 up to F4 fibrosis) and in 15 cases histopathologically proven liver cirrhosis. In 9 cases after non-acute thrombosis flow reduction of the portal vein was the reason for the diameter less than 5 mm. Flow parameters for the venous flow were between 8 cm/s up to 29 cm/s, mean 14±4 cm/s, for the hepatic portal vein 5 cm/s up to 57 cm/s, mean 17±5 cm/s, for the hepatic artery systolic flow between 50 cm/s up to 127±33 cm/s, end-diastolic flow from 22 cm/s up to 47 cm/s±8 cm/s. Resistance index for the hepatic artery was between 0.41 up to 0.73, mean 0.67±0.25. The image quality for CCDS over all cases was evaluated for CCDS between 1 up to 4. The mean quality was 2.5±0.5, for HR Flow in combination with Glazing flow 3±0.5, with significant differences for the 2 readers (P <  0.01).

CONCLUSION

Combination of HR Flow with Glazing Flow could be helpful to evaluate morphological und hemodynamic changes of liver arterial flow, portal venous and venous flow. Reduction of flow artefacts in combination with a higher image quality could be helpful for optimizing the digital measurements also for follow up examinations.

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.

Wireless point-of-care ultrasound: First experiences with a new generation handheld device

AIM:

To evaluate the diagnostic reliability of a new generation wireless point-of care ultrasound device for abdominal and thoracic findings.

MATERIAL AND METHODS:

40 patients (16 females, 24 males 19 –80 years, on average 56.1 years) were scanned by an experienced examiner using the new wireless Vscan Air device for abdominal and thoracic findings. The probe frequencies were 2–5 MHz (convex probe) and 3–12 MHz for the linear probe. As a reference standard, all patients were also examined using high-end ultrasound (LOGIQ E9/LOGIQ E10). Results were interpreted independently by two examiners in consensus, also with regard to the image quality (0–4, from not assessable = 0, to excellent 4).

RESULTS:

In all 40 patients (100%) examination with conventional high-end ultrasound and the Vscan Air ultrasound device was feasible. Sensitivity, specificity, positive and negative predictive value for the diagnosis of abdominal and thoracic findings were 63.3%, 100%, 100%, and 40%, respectively. Most main diagnostic findings were detected using the mobile device compared to the high-end ultrasound. Limitations were found regarding characterization and classification of hepatic and renal tumorous lesions.

Image quality revealed mostly minor diagnostic limitations for the mobile device, mean 2.9 (SD ± 0.300) and was excellent or with only minor diagnostic limitations for conventional high-end ultrasound, mean 3.25 (SD ± 0.438).

CONCLUSION:

Due to its easy application and its high diagnostic reliability, point-of-care ultrasound systems of the latest generation represent a valuable imaging method for the primary assessment of abdominal and thoracic findings, especially in patients on intensive care units or in emergency situations.

Liver stiffness assessed by shear-wave elastography declines in parallel with immunoregulatory proteins in patients with chronic HCV infection during DAA therapy

BACKGROUND

A rapid decline of liver stiffness (LS) was detected by non-invasive methods in patients with chronic hepatitis C (HCV) infection during treatment with direct-acting antivirals (DAA).

OBJECTIVE

To investigate the influence of inflammation on LS.

METHODS

We prospectively examined LS by sonographic shear-wave elastography in 217 patients during DAA therapy from treatment initiation (BL) to 12 weeks after end of therapy (SVR12). Demographic data, laboratory findings and serum levels of cytokines were determined.

RESULTS

Values of LS decreased from 1.86 m/s to 1.68 m/s (p = 0.01) which was most pronounced in patients who had F4 fibrosis at BL (3.27 m/s to 2.37 m/s; p <  0.001). Initially elevated values of aminotransferases, ferritin, IgG (p <  0.001 each) and international normalized ratio (p <  0.003) declined, thrombocyte count (p = 0.007) increased. Correlations of these laboratory parameters with BL levels of LS measurement (LSM) were most apparent in patients with F1-F3 fibrosis. Tumor necrosis factor (TNF)-α (p = 0.031), interleukin (IL)-10 (p = 0.005) and interferon y inducible protein (IP)-10 (p <  0.001) decreased in parallel with LSM under DAA therapy and corelated with BL values.

CONCLUSION

Decrease of systemic inflammatory parameters correlated with LSM under DAA therapy. We conclude that regression of LSM is attributable to the decline of inflammation rather than reflecting fibrosis.

Interstitial lung opacities in patients with severe COVID-19 pneumonia by bedside high-resolution ultrasound in association to CO2 retention

BACKGROUND

Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS).

OBJECTIVE

This single centre cross-section study aimed to grade the severity of pneumonia by bed-side lung ultrasound (LUS).

METHODS

A scoring system discriminates 5 levels of lung opacities: A-lines (0 points),≥3 B-line (1 point), coalescent B-lines (2 points), marked pleural disruptions (3 points), consolidations (4 points). LUS (convex 1-5 MHz probe) was performed at 6 defined regions for each hemithorax either in supine or prone position. A lung aeration score (LAS, maximum 4 points) was allocated for each patient by calculating the arithmetic mean of the examined lung areas. Score levels were correlated with ventilation parameters and laboratory markers.

RESULTS

LAS of 20 patients with ARDS reached from 2.58 to 3.83 and was highest in the lateral right lobe (Mean 3.67). Ferritin levels (Mean 1885μg/l; r = 0.467; p = 0.051) showed moderate correlation in spearman roh calculation. PaCO2 level (Mean 46.75 mmHg; r = 0.632; p = 0.005) correlated significantly with LAS, while duration of ventilation, Horovitz index, CRP, LDH and IL-6 did not.

CONCUSIONS

The proposed LAS describes severity of lung opacities in COVID-19 patients and correlates with CO2 retention in patients with ARDS.

Contrast enhanced ultrasound (CEUS) with parametric imaging and time intensity curve analysis (TIC) for evaluation of the success of prostate arterial embolization (PAE) in cases of prostate hyperplasia

AIM

To evaluate the use of dynamic contrast enhanced ultrasound (CEUS) with parametric color-coded imaging and time intensity curve analysis (TIC) for planning and follow-up after prostate arterial embolization (PAE).

MATERIAL/METHOD

Before and after selective iliacal embolization by PAE with a follow up of 6 months 18 male patients (43-78 years, mean 63±3.5 years) with histopathological proven benign prostate hyperplasia were examined by one experienced examiner. A multifrequency high resolution probe (1-6 MHz) was used for transabdominal ultrasound and CEUS with bolus injections of 2.4 ml sulphur-hexafluoride microbubbles. Independent evaluation of color-coded parametric imaging before and after PAE by in PACS stored DICOM loops from arterial phase (10-15 s) up to 1min were performed. Criteria for successful treatment were reduction of early arterial enhancement by changes of time to peak (TTP) and area under the curve (AUC) by measurements in 8 regions of interest (ROI) of 5 mm in diameter at the margin and in the center and changes from hyperenhancement in parametric imaging (perfusion evaluation of arterial enhancement over 15 s) from red and yellow to blue and green by partial infarctions. Reference imaging method was the contrast high resolution 3 tesla magnetic resonance tomography (MRI) using 3D vibe sequences before and after PAE and for the follow up after 3 and 6 months.

RESULTS

PAE was technically and clinically successful in all 18 patients with less clinical symptoms and reduction of the gland volume. In all cases color-coded CEUS parametric imaging was able to evaluate partial infarction after embolization with changes from red and yellow to green and blue colors in the embolization areas. Relevant changes could be evaluated for TIC-analysis of CEUS with reduced arterial enhancement in the arterial phase and prolonged enhancement of up to 1 min with significant changes (p = 0.0024). The area under the curve (AUC) decreased from 676±255.04 rU (160 rU-1049 rU) before PAE to 370.43±255.19 rU (45 rU-858 rU) after PAE. Time to peak (TTP) did not change significantly (p = 0.6877); TTP before PAE was 25.82±9.04 s (12.3 s-42.5 s) and after PAE 24.43±9.10 s (12-39 s). Prostate volume decreased significantly (p = 0.0045) from 86.93±34.98 ml (30-139 ml) before PAE to 50.57±26.26 ml (19-117 ml) after PAE. There were no major complications and, in most cases (14/18) a volume reduction of the benign prostate hyperplasia occurred.

CONCLUSION

Performed by an experienced examiner CEUS with parametric imaging and TIC-analysis is highly useful to further establish prostatic artery embolization (PAE) as a successful minimal invasive treatment of benign prostatic hyperplasia.

Functional ultrasound imaging of the venous valve of the great saphenous vein in the area around the crosse using the novel vector flow technique

PURPOSE: The aim of our pilot study is to consider if the new flow presentation of the vector flow (V-flow) allows an assessment of the valve morphology of the crosses with respect to an insufficiency. MATERIAL AND METHODS: We performed a total of 50 investigations in which we documented a complete valve closure at the so called “crosse” at the valve of the large saphenous vein, a delayed valve closure or an incomplete valve closure with consecutive insufficiency at the crosse. The valve function of the crosse is crucial for the development of varicosis. For our study we recorded age and gender of the patients. One patient in the study was suffering from Covid19. For the examinations we used a 3–9 MHz probe and a high-end ultrasound device. The examination was performed in a lying position and under quiet conditions. Before examination we practiced inhalation and exhalation as well as “pressing” or coughing with the patients, which resulted in a physiological closure of the venous valves. To rule out thrombosis, we carried out compression sonography on the legs. During the examination we documented the B-scan, the Color-Coded Duplex Sonography, the HR-flow and the V-flow for 3 seconds at the estuary of the crosses and incorporated these parameters into our measurements. Via V-flow, vectors can be imaged by representing the flow of erythrocytes and visually indicate a possible insufficiency due to delayed or incomplete valve closure. RESULTS: 31 of 50 patients (age 19–81years) showed a complete valve closure of the crosses, three of them suffered from thrombosis. In eight of the 50 study participants (age 45–79 years) a delayed valve closure could be diagnosed by V-flow within 1–2 seconds. None of them had a thrombosis, but six of them suffered from cancer. In eleven patients we derived an incomplete valve closure with insufficiency (age 51–88 years). With reflux it took >2 seconds to close the valve. The patient with Covid19 also showed an incomplete valve closure with insufficiency. At the same time this patient showed a Covid19-associated deep vein thrombosis. Eight additional patients also had a thrombosis. Six of them suffered from cancer. Overall, the results were best visualized by V-Flow. CONCLUSION: The crosse as a significant venous structure can be well investigated by V-flow with respect to hemodynamic changes and a resulted reflux. Also associated changes close to the valve can be visualized well.

Contrast-enhanced ultrasound with perfusion analysis in patients with venous malformations before and after percutaneous treatment with ethanol-gel

INTRODUCTION

Percutaneous sclerotherapy is a well-established treatment option for venous malformations (VM). A recently established sclerosing agent is ethanol-gel. Aim of this study was to identify, if contrast-enhanced ultrasound (CEUS) with an integrated perfusion analysis allows for differentiation between untreated VM, healthy tissue, and with gelified ethanol treated malformation tissue.

MATERIAL AND METHODS

In this institutional review board approved prospective study symptomatic VM patients underwent CEUS at exactly the same position before and after sclerotherapy with ethanol-gel. Two experienced sonographers performed all examinations after the bolus injection of microbubbles using a multi-frequency probe with 6 -9 MHz of a high-end ultrasound machine. An integrated perfusion analysis was applied in the center of the VM and in healthy, surrounding tissue. For both regions peak enhancement (peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT) were evaluated. Wilcoxon signed rank test was executed; p-values <0.05 were regarded statistically significant.

RESULTS

In 23 patients including children (mean age 25.3 years, 19 females) before treatment all identified parameters were significantly higher in the VM center compared to healthy tissue (peak: p < 0.01; TTP: p < 0.01; AUC: p < 0.01; MTT: p < 0.01). Comparing the VM center before and after treatment, TTP (p < 0.02) and MTT (p < 0.01) reduced significantly after sclerotherapy. In surrounding tissue only peak changed after treatment in comparison to pre-treatment results (p = 0.04). Comparing data in the VM center with surrounding tissue after sclerotherapy, results still differed significantly for peak (p < 0.01), TTP (p < 0.01), and AUC (p < 0.01), but assimilated for MTT (p = 0.07).

CONCLUSION

All with CEUS identified parameters seem to be excellent tools for differentiating between VM and healthy tissue. TTP and MTT could distinguish between with ethanol-gel sclerotized VM portions and untreated malformation parts and thereby might assist the monitoring of sclerotherapy with ethanol-gel.

Imaging of breast implant and implant-associated complications: Capsular contracture and intra- or extracapsular rupture

BACKGROUND

In recent years, follow-up after breast reconstruction with silicone implants and the detection of complications have been relieved by the possibility of improved diagnostic methods.

METHODS

Between January 2015 and December 2019 a total of 40 patients (29-84 years) with silicone implants were included in this retrospective study. The implants were examined clinically and with modern imaging: general ultrasound imaging (US), magnetic resonance imaging (MRI), high resolution computed tomography (CT) and positron emission tomography -computed tomography (PET-CT). If necessary, a histological/cytological sample was taken. The breast implants were assessed by three radiologists specialized in breast imaging. The grade of capsular contracture was classified according to the Baker classification.

RESULTS

All 40 women obtained a clinical examination and an US diagnostic to identify early and more common complications such as implant folding and capsular fibrosis. Depending on the clinical examination and ultrasound findings additional MRI (n = 10), CT (n = 9) and/or PET-CT (n = 2) were performed. 16 patients had implants folding proven with US (n = 16), MRI (n = 6) and CT (n = 1). The grade of capsular fibrosis was determined according to the Baker classification. The following results were obtained in our study: 25 breast implants with Baker grade I and eleven breast implants with Baker grade II, both proven with US; one breast implants with Baker grade III and one breast implant with Baker grade IV, proven with US (n = 2), MRI (n = 1) and CT (n = 1). One patient had intracapsular rupture and one patient had extracapsular rupture, both detected on CT and surgically proven. No patient had a silicone accumulation in the lymph nodes. One patient had pathologically enlarged axillary lymph nodes, which were evaluated as inflammatory changes in PET-CT. Long-term complications such as the development of malignant breast tumors could not be observed.

CONCLUSION

To detect early complications after breast implant surgery, a regular clinical examination is indispensable. Imaging methods complement each other and if they are used multimodal, it is easier to identify early complications. Modern diagnostic modalities like ultrasound and magnetic resonance imaging expand the spectrum and improve diagnostic safety.

Contrast enhanced ultrasound (CEUS) to assess pleural pulmonal changes in severe COVID-19 infection: First results

AIM:

Use of contrast enhanced ultrasound (CEUS) in severe cases of COVID-19 infection to assess pulmonary changes near the pleura.

MATERIAL AND METHODS:

Bedside examinations by an experienced intensive care unit examiner using a multi-frequency probe (C1-6 MHz) with B-mode and CEUS to assess pleural-near changes in severe cases of COVID-19 infection with respiratory failure. CEUS with bolus delivery via a central venous catheter of 2.4 ml Sulphur hexafluoride microbubbles from the arterial phase (10–15 s) to the late phase of 5 min. Digital storage of cine sequences of the lung sound with abdomen for independent assessment with the subsequently performed contrast-enhanced dual-source CT.

RESULTS:

In 11 intubated and ventilated patients (arithmetic mean 62 years, 48 to 78 years, 3 women) with confirmed severe COVID-19 infections, a peripherally accentuated consolidation with irregular hyperemia was found in the CEUS and also in the CT examination. Of the 5 cases with pulmonary arterial embolisms, signs of right ventricular failure were found. In all cases, using CEUS low perfused areas of the pleura with adjacent hyperemia could be detected, while, with CT segmental contrast medium, gaps with subpleural compressions were found. Interstitial changes near the pleura led to B-lines and to ground glass opacities in the CT. Near the diaphragm a delayed arterial contrast of the liver was observed. In addition, in 2 cases partial atelectasis, in 3 cases marginal pleural effusions were found.

CONCLUSION:

CEUS opens up new possibilities for bedside monitoring of pleural reactive inflammatory or peripheral thrombus embolism in severe cases of COVID-19 infection.

Contrast enhanced ultrasonography (CEUS) to detect abdominal microcirculatory disorders in severe cases of COVID-19 infection: First experience

In the hands of experienced examiners, the contrast enhanced sonography (CEUS) offers the possibility to analyze dynamic microcirculatory disturbances in real time dynamically without any risk for kidneys and thyroid gland even in severe progressing disease bedside. Based on severe COVID-19 infections, first experiences with abdominal CEUS examinations are presented. In the stage of an imminent organ failure with significantly reduced kidney and liver function, CEUS can be used to show a narrowing of the organ-supplying arteries, as well as a delayed capillary filling of vessels near the capsule, a regional reduced parenchymal perfusion or an inflammatory hyperemia with capillary hypercirculation. It is possible to quickly rule out organ infarction and to dynamically record the mesenteric arterial and venous blood flow.

53 Pre-implantation exposure to bisphenol A and 4-tert-octylphenol result in disruption of calcium channels

Miscarriage due to blastocyst implantation failure occurs in up to two-thirds of all miscarriage cases in humans. Calcium (Ca2+) has been shown to involve many cellular signal transduction pathways as well as regulation of cell adhesion, which is necessary for the physiology process of endometrial epithelial cell transformation and stromal cell decidualization during embryo implantation. Exposure to endocrine-disrupting chemicals (ED) can regulate the expression of genes associated with calcium transport in during pregnancy such as TRPV5, TRPV6, PMCA, and NCX1. Additionally, exposure to ED during early gestation results in disrupted intrauterine implantation, uterine receptive, leading to implantation failure. In this study, oestrogen (E2), bisphenol A (BPA), octylphenol (OP), and/or ICI 182,780 (oestrogen receptor antagonist, ICI) were injected subcutaneously from gestation Day 1 to gestation Day 3 post coitus. The number of implantation sites was significantly lower in the OP group, and no implantation site was observed in the E2 and ED+ICI groups. There were differences in the expression of calcium transient transport channel between maternal uterine and implantation. The level of TRPV6 and TRPV5 mRNA and protein was significantly increased by ED and/or ICI treatment in the uterus. The levels of TRPV5 and TRPV6 gene expression were significantly increased by ED with/without ICI treatment in the uterus. However, TRPV5 and TRPV6 gene expression was significantly lower in implantation site samples. The NCX1 and PMCA1 mRNA levels were significantly decreased by OP and BPA in the implantation site samples. Both mRNA and protein levels of MUC1 were markedly higher in all groups, except the BPA group when compared with the vehicle group in the uterus. The LIF and HOXA-10 mRNA were significantly low in E2; BPA+ICI; OP; and/or ICI in both the uterus and implantation site. Expression of the oestrogen receptor (ERa) and progesterone receptor (PR) was significantly lower in all groups except the BPA group when compared with the vehicle group. Taken together, E2, BPA, and OP disrupt the success of implantation through altered expression of calcium transport genes.

190 Effects of endocrine-disrupting chemical on calcium signalling in cardiomyocyte differentiation from mouse embryonic stem cells

Endocrine-disrupting chemicals (EDC) are substances similar to steroid hormones that can disturb normal physiological functions of male and female reproductive organs. Endocrine-disrupting chemicals tend to bind to steroid hormone receptors. Sex steroid hormones modulate calcium signalling in the cardiac muscle in early embryo development. Among the steroid hormones, progesterone (P4) has been reported to affect blood pressure and other aspects of the cardiovascular system. The EDC that have similar structure to P4, such as octyl-phenol (OP) and bisphenol A (BPA), are potentially harmful to development of the heart. To confirm the effect of OP and BPA on early differentiation of mouse embryonic stem cells (mES) into cardiomyocytes, the hanging-drop method with mESC cell line (ES-E14TG2a) was used for forming embryoid bodies. Pluripotent mESC were cultured in basal medium with leukemia inhibitory factor and grown on mitomycin C-treated mouse embryonic fibroblasts in a 60-mm plate at 37°C in a 5% CO2 humidified tissue culture incubator with basal medium consisting of DMEM/F-12 supplemented with nonessential amino acids, 10% heat-inactivated and certified fetal bovine serum (FBS), 2-mercaptoethanol, penicillin, and streptomycin. The mouse embryoid bodies (mEB) were suspended onto 6-well plates and cultured with differentiation medium containing steroid-free FBS without leukemia inhibitory factor. Progesterone, OP, and BPA were added on Day 2 from mEB attachment. In addition, mifepristone (RU486), an antagonist for progesterone receptor (PR), was used to confirm the effect of P4 through PR. To determine whether RU486 is capable of attenuating the inhibition effect of P4, RU486 was added for 1 day starting on Day 11. Assessment of cardiomyocyte differentiation was determined by checking the number of beating cell populations divided by the total number of attached mEB. Total RNA was extracted using Trizol reagent and synthesised to cDNA using Moloney murine leukemia virus (MMLV) reverse transcriptase. Messenger RNA level was assessed using quantitative real-time PCR. To investigate calcium signalling, the mRNA levels of calcium channel gene Trpv2 and contraction-related genes Ryr2, Cam2, and Mylk3 were analysed. Beating ratio was decreased in P4, OP, and BPA treatments. Data were analysed by one-way ANOVA followed by Tukey’s multiple comparison tests, and P&lt;0.05 was considered statistically significant in least 3 different replicates. The mRNA level of Pgr was significantly increased in P4, OP, and BPA-treated group. However, the mRNA level of calcium channel gene Trpv2 was significantly decreased in the P4, OP, and BPA-treated group. Expression of contraction-related genes such as Ryr2, Cam2, and Mlck3 were significantly decreased in the P4, OP, and BPA-treated group. In addition, treatment with RU486 rescues altered calcium channel gene and contraction-related genes. Taken together, these results suggest that OP and BPA may affect the differentiation of mESC into cardiomyocyte and disrupts differentiation of cardiomyocytes.

119 Combined exposure to phthalates and 4-vinylcyclohexene diepoxide accelerate the loss of ovarian follicles, leading to premature ovarian failure in rat model

Premature ovarian failure (POF) is observed in women under 40 years with primary or secondary amenorrhea. The causes for POF are idiopathic, genetic, iatrogenic incidence, autoimmunity, and adverse effects from toxic chemical exposures. Several classes of chemicals have been shown to alter follicle development and reduce fertility, leading to POF in mammals. We investigated the synergistic effects of 4-vinylcyclohexene diepoxide (VCD) and phthalates, including di(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), and di-n-butyl phthalate (DBP), on POF. Both VCD and these phthalates have been reported to disrupt the folliculogenesis and steroidogenesis in many species. In the vehicle group, female Sprague-Dawley rats (8 weeks of age) received an IP injection of corn oil daily for 2 weeks. The 7 other groups received VCD+corn oil, DEHP, DEHP+VCD, BBP, BBP+VCD, DBP, or DBP+VCD. After receiving the VCD or vehicle injection IP for 2 weeks, corn oil or a phthalate were orally administered once a day for the entire 6-week study period. The mRNA expressions of Amh and Sohlh2 were significantly decreased in the combination groups compared to the control and individual groups. Serum Amh levels were significantly lower in the combination groups. Additionally, serum levels of FSH were markedly higher in combination groups. Our findings suggest that the combination of VCD and phthalates can accelerate the POF by disturbance in folliculogenesis and hormone regulation.

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.

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.

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.

Effect of radiographic contrast media on renal perfusion - First results

BACKGROUND

Intra-arterial administration of radiographic contrast media (CM) is discussed to impair renal perfusion. The pathogenesis of contrast-induced Nephropathy (CIN) is still not clarified.

OBJECTIVE

This trial was performed to prove the effects of two CM with different molecular structure on renal perfusion.

METHODS

A prospective, randomized study on 16 pigs was designed to compare the outcome after application of a low-osmolar iodinated CM (770 mOsm/kg H2O - Group1) and an iso-osmolar iodinated CM (290 mOsm/kg H2o - Group2).Color Coded Doppler Sonography (LOGIQ E9, GE, Milwaukee, USA) was applied for measuring the Renal Resistive Index (RRI) before and after the first, fifth, and tenth bolus of CM. Statistics was performed using analysis of variance for repeated measurements with the Factor "CM".

RESULTS

All flow spectra were documented free of artifacts and Peak Systolic Velocity (PSV), Enddiastolic Velocity (EDV) and RRI respectively could be calculated. Mean PSV in Group 1 led to a decrease while in Group 2 PSV showed a significant increase after CM (p = 0,042). The course of the mean EDV in both groups deferred accordingly (p = 0,033). Mean RRI over time significantly deferred in both groups (p = 0,001). It showed a biphasic course in Group 2 and a decrease over time in Group 2.

CONCLUSION

While iso-osmolar CM induced an increase of PSV and EDV together with a decrease of RRI, low-osmolar CM could not show this effect or rather led to the opposite.

[Possibilities of sonographic image fusion: Current developments]

CLINICAL/METHODICAL ISSUE

For diagnostic and interventional procedures ultrasound (US) image fusion can be used as a complementary imaging technique.

METHODICAL INNOVATIONS

Image fusion has the advantage of real time imaging and can be combined with other cross-sectional imaging techniques.

PERFORMANCE

With the introduction of US contrast agents sonography and image fusion have gained more importance in the detection and characterization of liver lesions.

ACHIEVEMENTS

Fusion of US images with computed tomography (CT) or magnetic resonance imaging (MRI) facilitates the diagnostics and postinterventional therapy control.

PRACTICAL RECOMMENDATIONS

In addition to the primary application of image fusion in the diagnosis and treatment of liver lesions, there are more useful indications for contrast-enhanced US (CEUS) in routine clinical diagnostic procedures, such as intraoperative US (IOUS), vascular imaging and diagnostics of other organs, such as the kidneys and prostate gland.

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.

Percutaneous irreversible electroporation (IRE) of prostate cancer: Contrast-enhanced ultrasound (CEUS) findings

PURPOSE

To evaluate the use of contrast-enhanced ultrasound (CEUS) after irreversible electroporation (IRE) of prostatic cancer tissue to assess the ablation status by depicting microvascularisation in the ablation area.

MATERIALS AND METHODS

Retrospective evaluation of CEUS of 13 patients (mean age: 61.4 ± 7.5 years) with histologically confirmed prostatic cancer who underwent percutaneous IRE. In the course of clinical routine, the tumor lesions were documented before, immediately after, and 1 day after the ablationusing color-coded transabdominal and transrectal CEUS. The obtained image data (DICOM loops and images) were subsequently evaluated by 2 experienced radiologists and assessed with regard to micro vascularisation by means of a 5-point scale.

RESULTS

CEUS images showed significantly reduced microcirculation of the lesions (mean 0.9 ± 0.6 cm (0.5-1.5 cm) after IRE. Microcirculation was reduced from 2.15 ± 0.56 prior to ablation to 0.65 ± 0.63 (p <  0.001) immediately after the ablation and to 0.27 ± 0.44 one day after IRE (p <  0.001).

CONCLUSION

This study showed rapid and significant reduction of the microcirculation in the ablation area afterpercutaneous IRE of prostatic cancer tissue.

High-Resolution Ultrasound Including Contrast-Enhanced Ultrasound (CEUS) for the Detection of Gas Formation during Aspergillus Fumigatus Infection in Mice

PURPOSE

A. fumigatus infections represent a major threat for patients with a suppressed immune system. Early diagnosis is of importance for a favorable outcome but appears to be difficult due to limited diagnostic procedures. Here we investigated the sensitivity of high-resolution ultrasound (HRU) for the detection of A. fumigatus infection in the liver.

MATERIALS AND METHODS

BALB/c mice were intravenously infected with A. fumigatus and monitored by HRU, Doppler sonography (CCDS), contrast-enhanced ultrasound (CEUS), and real-time strain color-coded elastography (CCE) using a multi-frequency probe (6 - 15 MHz). Contrast media bolus injection of sulfur-hexafluoride micro-bubbles was applied and digital cine-loops from the arterial phase, as well as the portal venous phase up to the late phase of the whole liver were analyzed. All data were correlated to the histopathological findings.

RESULTS

Using HRU and CEUS, a sonic shadow was detected in all infected animals. All Aspergillus-infected nodes from 3 - 6 mm in the liver showed a shadow with rim enhancement and no intranodal enhancement when using CEUS. A. fumigatus infection was confirmed by CFU assessment and histopathological analysis. Granulomas were not associated with shadowing on B-mode. In contrast, granulomas with a diameter above 5 mm and a higher stiffness in CCE generated particularly an arterial rim enhancement and portal venous washout without contrast media uptake in the late phase. In addition, CEUS was able to define dynamic capillary microvascularization of infected liver areas.

CONCLUSION

Liver lesions associated with A. fumigatus infection can be detected in mice when combined with CEUS and CCE in vivo.

Improved Detection of preclinical Colorectal Liver Metastases by High Resolution Ultrasound including Molecular Ultrasound Imaging using the targeted Contrast Agent BR55

PURPOSE

Aim of the present study was to investigate the sensitivity of high resolution ultrasound (HRU), standard contrast-enhanced ultrasound (CEUS) and CEUS using a novel vascular endothelial growth factor receptor 2 (VEGFR2)-targeted contrast agent for the detection of hepatic metastases in a mouse model of colorectal cancer using clinical standard technology.

MATERIALS AND METHODS

The human colon cancer cell line HT29, transfected with luciferase cDNA for in vivo bioluminescence monitoring, was injected intrasplenically into CB17.SCID mice. Mice were monitored weekly by bioluminescence and after 2 and 4.5 weeks by HRU and CEUS. Contrast media (untargeted BR1, targeted BR55) was applied and digital cine loops from the arterial phase (15 - 45 sec), portal venous phase (50 - 120 s) and late phases (3 - 5 min, 1hour) of the whole liver were analyzed. Data were correlated with postmortem histopathology.

RESULTS

Without contrast enhancement, lesions > 4 mm were reliably detected. After use of untargeted CEUS, lesions > 2 mm were reliably detected and enhanced rim vascularization and late-phase wash-out was shown. With BR55, lesions > 0.8 mm were reliably detected with excellent documentation of vascularization. A persistent contrast enhancement was seen > 30 min after injection. Contrast-enhancement patterns with BR55 significantly correlated with CD31 (R2 = 0.74) and VEGFR2-immunohistochemistry (R2 = 0.66).

CONCLUSION

Detection of metastases by HRU and CEUS was earlier and more accurate than monitoring via bioluminescence. In vivo monitoring of hepatic micrometastases can thus be performed without prior modification of cancer cells using standard technology.