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

Multiparametric ultrasound evaluation of thyroid nodules

Thyroid nodules are common incidental findings. Most of them are benign, but many unnecessary fine-needle aspiration procedures, core biopsies, and even thyroidectomies or non-invasive treatments have been performed. To improve thyroid nodule characterization, the use of multiparametric ultrasound evaluation has been encouraged by most experts and several societies. In particular, US elastography for assessing tissue stiffness and CEUS for providing insight into vascularization contribute to improved characterization. Moreover, the application of AI, particularly machine learning and deep learning, enhances diagnostic accuracy. Furthermore, AI-based computer-aided diagnosis (CAD) systems, integrated into the diagnostic process, aid in risk stratification and minimize unnecessary interventions. Despite these advancements, challenges persist, including the need for standardized TIRADS, the role of US elastography in routine practice, and the integration of AI into clinical protocols. However, the integration of clinical information, laboratory information, and multiparametric ultrasound features remains crucial for minimizing unnecessary interventions and guiding appropriate treatments. In conclusion, ultrasound plays a pivotal role in thyroid nodule management. Open questions regarding TIRADS selection, consistent use of US elastography, and the role of AI-based techniques underscore the need for ongoing research. Nonetheless, a comprehensive approach combining clinical, laboratory, and ultrasound data is recommended to minimize unnecessary interventions and treatments.

Renal medullary perfusion differs from that in renal cortex in patients with sepsis associated acute kidney injury and correlates with renal function prognosis: A prospective cohort study

BACKGROUND

Renal perfusion status remains poorly studied at the bedside during sepsis associated acute kidney injury (AKI). The aim of the study is to examine renal cortical and medullary perfusion using renal contrast enhanced ultrasound (CEUS) in septic patients.

METHODS

In this single-center, prospective longitudinal study, septic patients were enrolled. Renal ultrasonography was performed within 24 hours of ICU admission (D1), then repeated at D3, D5 and D7. Each measurement consisted of three destruction replenishment sequences that were recorded for delayed analysis with dedicated software (Vuebox). Renal cortex and medulla perfusion were quantified by measuring time to peak (TTP). Receiver operating characteristic (ROC) analysis was used to evaluate 28-day renal prognosis.

RESULTS

The study included 149 septic patients, including 70 non-AKI patients and 79 AKI patients. Both renal cortical and medullary TTP was longer in the AKI group than in the non-AKI group. The difference of TTP between renal cortex and medulla in AKI group was higher than that in the non-AKI group (p = 0.000). Medullary TTP on day 3 had the best performance in predicting the prognosis of 28-day renal function (AUC 0.673, 95% confidence interval 0.528-0.818, p = 0.024), and its cut-off value was 45 s with a sensitivity 52.2% and a specificity of 82.1%. Cortical TTP on day 3 also had the performance in predicting the prognosis of 28-day renal function (AUC 0.657, 95% confidence interval 0.514-0.800, p = 0.039), and its cut-off value was 33 s with a sensitivity 78.3% and a specificity of 55.0%.

CONCLUSION

Renal medullary perfusion alterations differ from those in cortex, with the medulla is worse. Simultaneous and dynamic assessment of cortical and medullary microcirculatory flow alterations necessary. TTP on day 3, especially medullary TTP, seems to be a relatively stable and useful indicator, which correlates with 28-day renal function prognosis in septic patients. Early correction of renal cortical and medullary perfusion alterations reduces the incidence of adverse renal events.

Contrast-enhanced ultrasound of polyp malignant transformation with multiple metastases in a patient with Peutz-Jeghers syndrome

Multi-systemic metastasis in patients with Peutz-Jeghers syndrome (PJS) is very rare, and there are nearly no relevant imaging reports, especially in contrast-enhanced ultrasound (CEUS). We present here a 40-year-old male patient who underwent several partial small bowel resections and endoscopic polypectomy for intestinal polyps. After reviewing the patient's clinical diagnosis and treatment process, CEUS with sulfur hexafluoride microbubbles (SonoVue, Bracco, Milan, Italy) in the liver and gastrointestinal tract was performed. We imaged multiple abnormal masses with sonographic features consistent with malignancies. Combined with other imaging examinations and 18 gauge core-needle puncture biopsy of liver masses, multiple metastases outside the gastrointestinal tract were considered. This case report suggests CEUS may be an easy, effective, and supplementary method for evaluating PJS patients with suspected multi-systemic malignant lesions including the gastrointestinal tract.

The value of sonographic microvascular imaging in the diagnosis of lipedema

BACKGROUND

Lipedema is a chronic disease marked by symmetric enlargement of painful nodular and fibrotic adipose tissue, predominantly affecting the limbs. Since there is no specific test or biomarker for this condition, years often pass before the diagnosis of lipedema is established for the first time, thereby causing psychosocial distress, including depression, eating disorders, and social isolation. Over the last few years several advanced Doppler-based technologies have been developed to visualize slow flow blood vessels and superficial microvascular architecture undetectable by traditional color Doppler flow imaging (CDFI).

OBJECTIVE

The aim of this study was to evaluate the superficial microvascular anatomy in lipedema patients compared to healthy controls and investigate the clinical significance of the Ultra Micro Angiography (UMA) technology in the diagnosis of lipedema. This new technique may contribute to reduce the diagnostic delay and, eventually, establish and guide treatment strategies toward a better therapeutic outcome in lipedema patients.

METHODS

25 patients with lipedema and ten healthy controls with no history of lipedema were included in this study. All ultrasound examinations were performed on a novel high-performance ultrasound system (Resona R9/Mindray) using CDFI and the UMA technique.

RESULTS

In all of the patients, Ultra Micro Angiography achieved the excellent visualization of microvascular structures, revealing that most lipedema patients showed grade 3 (n = 13) or grade 2 (n = 8) flow. UMA was superior to CDFI for depicting the microvascular structures.

CONCLUSIONS

Here we show that UMA imaging characterizes the subcutaneous microvasculature with an unprecedented accuracy. The method has the advantage of being sensitive to small, slow-flowing vessels. This allows for the assessment of the course of vessels and vascular pathologies in great detail. Thus, UMA as a non-invasive diagnostic method can improve diagnostic accuracy in lipedema.

Hepatic steatosis using ultrasound-derived fat fraction: First technical and clinical evaluation

OBJECTIVES

To explore the technical and clinical evaluation of ultrasound-derived fat fraction (UDFF) measurement in adult patients in whom fatty liver was suspected.

MATERIALS AND METHODS

In this prospective study, 41 participants were initially enrolled in our hospital between October 2022 and December 2022 and received UDFF assessment using Siemens ACUSON Sequoia system equipped with DAX transducer. UDFF measurement was performed three times to obtain UDFF values from each imaging location (V hepatic segment and VIII hepatic segment) per participant, and the depth (skin-to-capsule distance) was automatically measured. The echogenicity of liver tissue in B mode ultrasound (BMUS) was compared to the normal kidney tissue, and fatty liver was graded as mild (Grade 1), moderate (Grade 2), and severe (Grade 3). The median of the acquired overall median UDFF values was used for statistical analysis. All ultrasound examinations were performed by one of two radiologists (with 20 and 10 years of liver ultrasound imaging experience).

RESULTS

Finally, UDFF measurement was successfully performed on 38 participants to obtain valid values, including 21 men with a median age of 40.0 years (interquartile range [IQR]: 23.0 - 58.5) and 17 women with a median age of 60.0 years (IQR: 29.5 - 67.0). Fatty liver was diagnosed by BMUS features in 47.4% (18/38) participants. Among all participants, the median UDFF value was 7.0% (IQR: 4.0 - 15.6). A significant difference in UDFF values was found between participants with fatty liver and without fatty liver (U = 7.0, P < 0.001), and UDFF values elevated as the grade of the fatty liver increased (P < 0.001). The median UDFF values from the three UDFF measurements obtained during each ultrasound examination showed excellent agreement (ICC = 0.882 [95% confidence interval: 0.833 - 0.919]). The Spearman correlation of UDFF values in different depths was moderate, with a rs value of 0.546 (P < 0.001). No significant differences in UDFF values were found between V hepatic segment and VIII hepatic segment (U = 684.5, P = 0.697).

CONCLUSIONS

UDFF provides a novel non-invasive imaging tool for hepatic steatosis assessment with excellent feasibility.

Contrast-enhanced ultrasound features of hepatic sarcomatoid carcinoma different from hepatocellular carcinoma

BACKGROUND

Hepatic sarcomatoid carcinoma (HSC) is a rare malignancy of the liver. The ultrasound and clinical features of HSC have not been determined.

OBJECTIVE

To investigate and compare the ultrasound and clinical features of HSC and hepatocellular carcinoma (HCC), and to reveal the valuable features of HSC.

METHODS

The ultrasound features and clinical data of pathologically proven HSC (n = 37) were compared with HCC (n = 92) in a matching ratio of 1:4 using the propensity score (age, gender and tumor size).

RESULTS

The HSC patients were more likely to accompany with clinical symptoms and vascular invasion than HCC patients (40.5% vs 17.4%, 24.3% vs 6.5%, P < 0.05). The size of HSCs was significantly larger than that of HCCs (P < 0.05). The proportion of patients with elevated alpha-fetoprotein was significantly lower in HSC (35.1% vs 54.3%, P < 0.05). On gray-scale ultrasound images, the HSCs were more likely to demonstrate as indistinct margin and irregular shape lesions compared to HCCs (78.4% vs 48.8%; 70.3% vs 23.9%, P < 0.05). Under color Doppler flow imaging (CDFI), the blood flow signals were more frequently detected in HSC lesions (75.7% vs 56.5%, P < 0.05). Resistance index (RI) was higher in HSCs than in HCCs [0.78 (0.70,0.82) vs 0.70 (0.62,0.76), P < 0.05]. On contrast-enhanced ultrasound (CEUS), HSCs mainly showed entirety heterogeneous hyper-enhancement (48.6%), entirety homogeneous enhancement (18.9%), peripheral and internal septal enhancement (18.9%). The incidence of non-enhanced areas inside HSC lesions was higher than that inside HCC lesions (56.8% vs 31.5%, P < 0.05). During the portal venous and late phases, most of the lesions revealed hypo-enhancement in both groups, whereas earlier washout was observed in HSCs [43.0 s (30.5,58.0) vs 60.0 s (46.3,100.0), P < 0.05].

CONCLUSIONS

CEUS features are useful in preoperative and non-invasive differentiation of hepatic sarcomatoid carcinoma and hepatocellular carcinoma.

Reactive lymphoid hyperplasia of the liver: A rare case report

BACKGROUND

Hepatic reactive lymphoid hyperplasia (RLH) is a rare benign lymphoproliferative lesion and a poorly understood disease. It is usually asymptomatic and incidental, but it is difficult to distinguish from hepatocellular carcinoma and metastatic liver tumor on imaging, and percutaneous biopsy is not sufficient to distinguish from low-grade malignant lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), making diagnosis difficult.

CASE SUMMARY

A 69-year-old woman came to our hospital for reexamination of pulmonary nodules followed by liver occupation. The lesions showed "wash-in and wash-out" on contrast-enhanced ultrasonography and magnetic resonance imaging. Enhanced magnetic resonance also showed annular envelope enhancement and limited diffusion on the ADC map during the delay period. Imaging revealed metastatic liver cancer, and the patient underwent a partial hepatectomy. However, the final histopathological diagnosis was RLH.

CONCLUSION

If small isolated nodules are found in the liver of middle-aged and elderly female patients with no risk factors for liver malignancy, when the enhanced imaging suggests "wash-in and wash-out", further focus should be placed on whether the enhanced imaging shows perinodular enhancement and whether the DWI shows limited diffusion in MRI, in order to emphasize the possibility of liver RLH diagnosis.

Novel high-resolution contrast agent ultrasound techniques HiFR CEUS and SR CEUS in combination with shear wave elastography, fat assessment and viscosity of liver parenchymal changes and tumors

BACKGROUND

The continuous development of ultrasound techniques increasingly enables better description and visualization of unclear lesions. New ultrasound systems must be evaluated with regard to all these diagnostic possibilities.

METHODS

A multifrequency C1-7 convex probe (SC7-1M) with the new high-end system Resona A20 Series was used. Modern technologies, including HiFR CEUS, SR CEUS and multimodal tissue imaging with shear wave elastography (SWE), fat evaluation and viscosity measurements (M-Ref) were applied.

RESULTS

Of n = 70 (mean value 48,3 years±20,3 years, range 18-84 years) cases examined, a definitive diagnosis could be made in n = 67 cases, confirmed by reference imaging and/or follow-up. Of these, n = 22 cases were malignant changes (HCC (hepatocellular carcinoma) n = 9, CCC (cholangiocellular carcinoma) n = 3, metastases of colorectal carcinomas or recurrences of HCC n = 10). In all 12 cases of HCC or CCC, the elastography measurements using the shear wave technique (with values >2 m/s to 3.7 m/s) showed mean values of 2.3±0.31 m/s and a degree of fibrosis of F2 to F4. In n = 14 cases, changes in the fat measurement (range 0.51 to 0.72 dB/cm/MHz, mean values 0.58±0.12 dB/cm/MHz) in the sense of proportional fatty changes in the liver were detected. In the 4 cases of localized fat distribution disorders, the values were >0.7 dB/cm/MHz in the sense of significant fatty deposits in the remaining liver tissue. Relevant changes in the viscosity measurements with values >1.8 kPa were found in n = 31 cases, in n = 5 cases of cystic lesions with partially sclerosing cholangitis, in n = 13 cases of malignant lesions and in n = 9 cases post-interventionally, but also in n = 4 cases of benign foci with additional systemic inflammation.

CONCLUSIONS

The results are promising and show a new quality of ultrasound-based liver diagnostics. However, there is a need for further investigations with regard to the individual aspects, preferably on a multi-center basis.

Pitfalls and strategies of Sonazoid enhanced ultrasonography in differentiating metastatic and benign hepatic lesions

OBJECTIVE

This article aims to clarify pitfalls and find strategies for the detecting and diagnosing hyperechoic liver metastases (LMs) using Sonazoid-contrast enhanced ultrasonography (Sonazoid-CEUS).

METHODS

This study was a prospective self-controlled study. Patients with hepatic lesions suspected as LMs or benign lesions were included in the study. Baseline ultrasonography (BUS) and Sonazoid-CEUS were performed on every patient. Characteristics of LMs and benign nodules were compared by chi-square test and fisher test. Factors influenced the CEUS were demonstrated by univariate analysis and multivariate logistic regression analysis.

RESULTS

54 patients were included in this study. CEUS found additional 75 LMs from 19 patients in Kupffer phase. We found hyperechoic focal liver lesions and deep seated in liver are main confounding factors in CEUS diagnosis. Sensitivity would be improved from 16.67% to 78.57%, negative predictive value (NPV) would be improved from 28.57% to 76.92% and accuracy would be improved from 37.5% to 87.50% when using rapid "wash-in" and "wash-out" as main diagnostic criteria.

CONCLUSIONS

Hyperechoic LMs especially deeply seated ones are usually not shown typical "black hole" sign in Kupffer phase. Quickly "wash-in and wash out" shows high accuracy in diagnosing malignant nodules. We highly recommend CEUS as a routing exam to detect and diagnose LMs.

Normal value of virtual touch imaging quantification elastography in measurements of pancreas

OBJECTIVE

To evaluate pancreatic tissue stiffness and provide a normal reference shear wave velocity (SWV) value of pancreas from healthy adults by Virtual Touch Imaging Quantification (VTIQ) measurements.

METHODS

Healthy adult volunteers without known history of hepatobiliary or pancreatic diseases were included. VTIQ elastography (Siemens ACUSON Sequoia, 5C-1 transducer) was used. SWV values were measured at the cephalic, corpus and tail of pancreas and replicated different operators' obtained data. Subgroups were classified according to the volunteers' gender, age, body mass index (BMI), depth of measurements and the echogenicity of the pancreas.

RESULTS

From February 2023 to July 2023, 33 healthy adult volunteers were included. The success rate of VTIQ measurements in cephalic, corpus and tail regions was 90.90 % (30/33), 96.97 % (32/33) and 90.90 % (30/33) respectively. The color elastograms of healthy adult pancreas showed uniform blue or simultaneously blue and green. The average SWV values were 0.97±0.26 m/s for cephalic, 0.91±0.24 m/s for corpus and 0.97±0.25 m/s for pancreatic tail respectively (P = 0.198). The mean SWV values of pancreas did not show significant difference with age, gender or depth (P > 0.05). BMI was an influence factor in the measurements of SWV values of cephalic and tail of pancreas (P < 0.05). Pancreas with hyperechoic parenchyma showed higher mean SWV values (P < 0.05). The intra-observer (ICC = 0.938 [95% CI: 0.869-0.971]) and the inter-observer (ICC = 0.887 [95% CI: 0.760-0.947]) agreements of VTIQ measurements were excellent.

CONCLUSIONS

The mean SWV value of the pancreas in healthy adults was 0.96±0.20 m/s (range: 0.52-1.74 m/s). VTIQ technique can be used in pancreatic stiffness measurements with good reliability.

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.

Washout appearance of hepatocellular carcinomas using standardized contrast-enhanced ultrasound (CEUS) including an extended late phase observation - Real-world data from the prospective multicentre DEGUM study

BACKGROUND

Non-invasive diagnosis of hepatocellular carcinoma (HCC) in contrast-enhanced ultrasound (CEUS) is based on the combination of arterial phase hyperenhancement (APHE) and subsequent late (>60 seconds) and mild contrast washout (WO). Whereas APHE is seen in the majority of HCC, wash-out pattern may vary in onset and intensity. In some HCC lesions, even no washout is seen at all.

OBJECTIVE

Our prospective multicentre DEGUM HCC CEUS study aimed at identifying typical and atypical washout appearance of HCC in a real-life setting.

METHODS

High-risked patients for HCC with focal liver lesions upon B-mode ultrasound were recruited prospectively. In a multicentre real-life setting, a standardised CEUS examination including an extended late phase up to 6 minutes was performed. CEUS patterns of HCC were recorded, and onset and intensity of washout appearance were assessed with respect to patient and tumour characteristics. Histological findings served as reference standard.

RESULTS

In 230/316 HCC (72.8%), a CEUS pattern of APHE followed by WO was observed. In 158 cases (68.7%), WO was typical (onset > 60 seconds, mild intensity). 72 cases (31.3%) showed marked and / or early WO, whereas in 41 HCCs (13%), APHE was followed by sustained isoenhancement.Atypical WO upon CEUS was associated with macroinvasion of the liver vessels, portal vein thrombosis and diffuse growth pattern, but not tumour size and histological grading.

CONCLUSIONS

In a prospective multicentre real-life setting, APHE is followed by atypical washout appearance or no washout at all in almost half of the HCCs with APHE. The examiner has to bear in mind that in spite of a characteristic APHE in HCCs, washout appearance can be atypical in CEUS, especially in HCCs with macrovascular invasion or diffuse growth pattern.

Predicting glypican-3 expression in hepatocellular carcinoma: A comprehensive analysis using combined contrast-enhanced ultrasound and clinical factors

OBJECTIVE

Glypican-3 (GPC3) has emerged as a significant marker for the diagnosis and prognosis of hepatocellular carcinoma (HCC) and has garnered considerable attention as an immunotherapeutic target. In this study, we propose a combination of preoperative contrast-enhanced ultrasound (CEUS) imaging features and clinical factors to predict the positive expression of GPC3 in HCC patients.

METHODS

We retrospectively included 30 cases of GPC3-negative HCC and 115 cases of GPC3-positive HCC patients who underwent conventional ultrasound and CEUS evaluation. We assessed and compared the clinical characteristics, conventional ultrasound features, and CEUS features between the two groups of HCC patients. Based on the clinical and ultrasound features between the two groups, we developed a binary logistic regression model for predicting GPC3-positive HCC.

RESULTS

A total of 145 HCC patients were included in this study. Binary logistic regression analysis showed that AFP > 20 ng/mL (OR = 4.047; 95% CI: 1.467-11.16; p = 0.007), arterial phase hyperenhancement (APHE) (OR = 12.557; 95% CI: 3.608-43.706; p < 0.001), and asynchronous perfusion (OR = 4.209; 95% CI: 1.206-14.691; p = 0.024) were predictive factors for GPC3-positive HCC. Receiver operating characteristic (ROC) analysis was conducted to predict GPC3-positive expression. The model combining the three independent predictive factors showed good predictive performance (AUC 0.817, 95% CI: 0.731-0.902, sensitivity: 91.3%, specificity: 60.0%). This combined model demonstrated excellent discriminatory ability to predict GPC3-positive HCC.

CONCLUSION

Preoperative integration of CEUS features and clinical factors can non-invasively and effectively identify GPC3-positive HCC patients, providing valuable assistance in making personalized treatment decisions.