Malignancies after liver transplantation: Value of contrast-enhanced ultrasound (CEUS)

Evaluation of Cardiac Space-Occupying Lesions by Myocardial Contrast Echocardiography and Transesophageal Echocardiography

Heart space-occupying lesions are a disease that occurs frequently in clinical setting, and therefore, it is important to diagnose and treat this type of pathologies properly. Angiographic echocardiography and transesophageal sonogram are widely used for clinical diagnosis. Their application provides a guarantee for the diagnosis of cardiac space-occupying lesions. In this paper, the application of cardiac contrast echocardiography and transesophageal echocardiography in cardiac space-occupying lesions was studied. Prediction of cardiac lesions can accurately determine the nature of cardiac occupancies and provide a basis for clinical diagnosis and management judgments. The results of pathological analysis and experimental comparison showed that myocardial contrast echocardiography can accurately distinguish tumor and thrombus and make contribution to patients taking appropriate medical measures. At the same time, it can compare conventional transthoracic echocardiography and transesophageal echocardiography. The results showed that TEE could clearly show the cardiac lesions. The experimental data of 76.9% confirmed cases showed that the diagnostic accuracy is greatly improved. TEE can also clearly show small thrombus that TTE cannot, in which 2DTEE can clearly show the boundary between the space-occupying and surrounding tissues, and whether there is a clear boundary between the space-occupying and surrounding tissues is an important distinguishing point of benign and malignant tumors. In addition, the TEE probe can also be used for large angle imaging and multiangle rotation, so as to determine the tumor boundary and the spatial position relationship between the tumor and the surrounding tissue. All in all, myocardial contrast echocardiography and transesophageal echocardiography have better clinical application effect on cardiac space-occupying lesions.

Contrast-enhanced ultrasound of transplant organs - liver and kidney - in children

Ultrasound (US) is the first-line imaging tool for evaluating liver and kidney transplants during and after the surgical procedures. In most patients after organ transplantation, gray-scale US coupled with color/power and spectral Doppler techniques is used to evaluate the transplant organs, assess the patency of vascular structures, and identify potential complications. In technically difficult or inconclusive cases, however, contrast-enhanced ultrasound (CEUS) can provide prompt and accurate diagnostic information that is essential for management decisions. CEUS is indicated to evaluate for vascular complications including vascular stenosis or thrombosis, active bleeding, pseudoaneurysms and arteriovenous fistulas. Parenchymal indications for CEUS include evaluation for perfusion defects and focal inflammatory and non-inflammatory lesions. When transplant rejection is suspected, CEUS can assist with prompt intervention by excluding potential underlying causes for organ dysfunction. Intracavitary CEUS applications can evaluate the biliary tract of a liver transplant (e.g., for biliary strictures, bile leak or intraductal stones) or the urinary tract of a renal transplant (e.g., for urinary obstruction, urine leak or vesicoureteral reflux) as well as the position and patency of hepatic, biliary and renal drains and catheters. The aim of this review is to present current experience regarding the use of CEUS to evaluate liver and renal transplants, focusing on the examination technique and interpretation of the main imaging findings, predominantly those related to vascular complications.

Diagnostic Value of CEUS Prompting Liver Biopsy: Histopathological Correlation of Hepatic Lesions with Ambiguous Imaging Characteristics

Background: Contrast-enhanced ultrasound (CEUS) allows for dynamic analysis of vascularization patterns of unclear hepatic lesions. Our study aimed to evaluate the diagnostic performance of CEUS for further characterizing suspicious liver lesions by comparing findings from CEUS examinations with corresponding histopathology. Methods: Between 2005 and 2016, 160 patients with unclear liver lesions underwent CEUS followed by liver biopsy. All examinations were performed by an experienced consultant radiologist (EFSUMB Level 3) and included native B-mode ultrasound, Color Doppler, and CEUS. A second-generation blood pool contrast agent was applied for CEUS. Results: CEUS was successfully performed in all patients without occurrence of any adverse side effects. CEUS showed a sensitivity of 94.5%, a specificity of 70.6%, a true positive rate of 87.3%, and a true negative rate of 85.7% compared to histopathological results as the reference standard. Conclusions: CEUS represents a safe imaging modality with a high diagnostic accuracy in assessing both—benign and malignant—liver lesions compared to corresponding histopathological results.

[CEUS-diagnosis of benign liver lesions]

CLINICAL/METHODICAL ISSUE

Focal liver lesions are commonly seen during routine ultrasound examinations.

STANDARD RADIOLOGICAL METHODS

With native ultrasound there are lesions that cannot be sufficiently characterized. In these cases additional imaging might be necessary.

METHODICAL INNOVATIONS

With contrast-enhanced ultrasound (CEUS), focal liver lesions can be characterized with high diagnostic accuracy. After the ultrasound contrast agent has been injected into a peripheral vein, the examiner saves video loops of the arterial, portal venous and late contrast phases. Combing the findings of native and contrast-enhanced ultrasound allows not only assessment of the etiology as benign or malignant but also detailed characterization of the focal liver lesion in most cases.

PERFORMANCE

Using CEUS, focal liver lesions can be characterized with a sensitivity of over 95% and a specificity of about 83%.

ACHIEVEMENTS

The advantages of CEUS include that there is no radiation exposure and that the ultrasound contrast agent has no effects on the function of the liver, kidneys or the thyroid gland. The main limiting factors for CEUS are bowel gas and obesity of the patient.

PRACTICAL RECOMMENDATIONS

CEUS can visualize micro- and macrovascularization of benign focal liver lesions in real time. It is a useful imaging modality in unclear cases.

Color coded perfusion imaging with contrast enhanced ultrasound (CEUS) for post-interventional success control following trans-arterial chemoembolization (TACE) of hepatocellular carcinoma

Aim

Evaluation of an external color coded perfusion quantification software with CEUS for the post-interventional success control following TACE in patients with HCC.

Material and methods

31 patients (5 females, 26 males, age range 34–82 years, mean 66.8 years) with 59 HCC lesions underwent superselective TACE using DSM Beads between 01/2015 and 06/2018. All patients underwent CEUS by an experienced examiner using a convex multifrequency probe (1–6 MHz) within 24 hours following TACE to detect residual tumor tissue. Retrospective evaluation using a perfusion quantification software regarding pE, TTP, mTT, Ri and WiAUC in the center of the lesion, the margin and surrounding liver.

Results

In all lesions, a post-interventional visual reduction of the tumor microvascularization was observed. Significant differences between center of the lesion vs. margin and surrounding liver were found regarding peak enhancement (867.8 ± 2416 center vs 2028 ± 3954 margin p<0.005) and center 867.8 ± 2416 vs 2824 ± 4290 surrounding liver, p<0.0001)). However, no significant differences were found concerning Ri, WiAuC, mTT and TTP.

Conclusion

CEUS with color- coded perfusion imaging is a valuable supporting tool for post-interventional success control following TACE of liver lesions. Peak enhancement seems to be the most valuable parameter.

[Contrast-enhanced ultrasound (CEUS) of the liver : Critical evaluation of use in clinical routine diagnostics]

CLINICAL/METHODICAL ISSUE

Focal liver lesions are common incidental findings in abdominal ultrasound diagnostics.

STANDARD RADIOLOGICAL METHODS

Characterization of focal liver lesions solely based on b‑mode and color duplex is not feasible in all cases.

METHODICAL INNOVATIONS

Using contrast-enhanced ultrasound (CEUS) it is possible to dynamically visualize the vascularization of focal liver lesions, which enables the characterization of benign and malignant liver tumors. The advantages of CEUS are that ultrasound contrast media do not show renal, hepatic or cardiac toxicity and do not influence the thyroid gland. The approach by fusion of CEUS and contrast-enhanced cross-sectional imaging combines the advantages of both imaging modalities.

PERFORMANCE

Using CEUS focal liver lesions can be characterized with a diagnostic accuracy greater than 90%.

ACHIEVEMENTS

The use of CEUS has become an important imaging modality to evaluate unclear liver lesions.

PRACTICAL RECOMMENDATIONS

The use of CEUS provides vital information as a supplement to cross-sectional imaging and it has become an important tool in therapy planning, control and monitoring of malignant liver lesions.