Contrast-enhanced Ultrasound Research Articles

Diagnostic Value Of Contrast Enhanced Ultrasound (CEUS) Compared To Standard Imaging Techniques For Evaluation Of Hepatic Lesions: A Systematic Review

Background: Liver metastasis is a critical concern in the realm of cancer, underscoring the importance of vigilant surveillance, accurate diagnosis, and timely detection. Contrast-Enhanced Ultrasound (CEUS) has the potential to be used as a diagnostic tool in detecting and diagnosing hepatocellular malignancies, lesions, and metastases in humans. This systematic review evaluates and summarises study results to compare the diagnostic value of CEUS to conventional imaging modalities of CT or MRI, providing valuable insights for the field. Methods: A comprehensive literature search was performed using PubMed/Medline, Wiley Online library, and Research gate to identify articles reporting the diagnostic performance of CT and MRI for detecting hepatic lesions. Results: A total of 11 studies were included in this review. Majority of studies ( 9 out of 11) concludes that CEUS has potential to become a useful diagnostic modality in diagnosis, as it shows comparable or better results to the standard techniques. Sensitivity and specificity averages were 85% and 82% for CEUS, 82.4% and 85% for CT, and 88.6% and 78% for MRI, respectively. While most studies favored CEUS, nuances exist, such as CEUS's limitations in deep liver regions and variations in sensitivity compared to MDCT. Conclusion: CEUS shows high diagnostic performance for tumor differentiation, with a high predictive value for malignant lesion. The results from the 11 studies comparing CEUS with standard imaging techniques provides valuable insights into the diagnostic potential of the CEUS in diverse clinical contexts

Contrast-Enhanced Ultrasound Compared With Hepatobiliary Agent MRI for Differentiation of Focal Nodular Hyperplasia and Hepatic Adenoma: A Prospective Trial.

Magnetic resonance imaging (MRI) may be time-consuming, expensive, or poorly tolerated by patients with liver lesions. This is a prospective clinical trial designed to evaluate if contrast-enhanced ultrasound (CEUS) can be used to differentiate focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA) with similar accuracy compared with hepatobiliary agent MRI.Institutional review board approval was obtained (1805450097), and the trial was registered with ClinicalTrials.gov (NCT03652636). From 2018 through 2023, 40 patients who had lesions consistent with FNH or HCA on HBA-MRI underwent 1-time prospective CEUS of up to 2 hepatic lesions. Sonographic images obtained before and after intravenous administration of 2 mL sulfur hexafluoride lipid-type A microspheres (Lumason) per lesion totaling 59 lesions (27 FNHs/32 HCAs). Two blinded radiologists provided a diagnosis of FNH or HCA.Thirty-eight female and 2 male patients (age 36.7 ± 9.9) were scanned. Radiologists provided diagnosis of FNH or HCA with respective sensitivity (66.7/64.0%), specificity (71.9/90.6%), and accuracy (69.5/78.0%). For 38 lesions greater than or equal to 2 cm in size (17 FNHs/21 HCAs), readers had sensitivity (70.6/84.2%), specificity (70.6/84.2%), and accuracy (81.5/86.8%). Interobserver agreement for all lesions was fair (κ = 0.34), whereas agreement for lesions 2 cm or larger was substantial (κ = 0.67).Contrast-enhanced ultrasound can differentiate FNH from HCA with accuracy approaching that of hepatobiliary agent MRI for lesions 2 cm or greater. Interobserver agreement is improved with larger lesions. CEUS may have utility as an alternate diagnostic tool for FNH/HCA, especially in patients who cannot or do not desire to undergo MRI.

Review of Clinical Applications of Sonazoid Ultrasound Contrast for Liver Evaluation.

Sonazoid is a new ultrasound contrast agent with unique Kupffer phase imaging advantages and high mechanical index stability. This paper introduces the basic theories and advantages of Sonazoid ultrasound. Then, the application and latest advances of Sonazoid in the diagnosis and treatment of liver diseases are reviewed in detail. In addition, the advantages and disadvantages of Sonazoid ultrasound and its future directions are discussed. Sonazoid is expected to become an important tool for clinical ultrasound diagnosis and treatment.

Diagnostic Efficacy of Multimodal Ultrasound for Mass and Non-Mass Enhancements in Dynamic Contrast-Enhanced MRI of Idiopathic Granulomatous Mastitis and Breast Cancer

PurposeIdiopathic granulomatous mastitis (IGM) poses diagnostic challenges due to its diverse clinical and radiological presentations, often mimicking malignancies. This study aimed to assess the diagnostic efficacy of multimodal ultrasound for mass and non-mass enhancements in Dynamic Contrast-Enhanced MRI (DCE-MRI) of IGM and breast cancer. MethodsA retrospective analysis involved patients confirmed histopathologically with IGM and BC. All patients underwent conventional ultrasound (C-US), ultrasound elastography (UE), contrast-enhanced ultrasound (CEUS), and DCE-MR examinations. Blind experienced radiologists assessed imaging findings. Diagnostic accuracy, sensitivity, and specificity were calculated for mass and non-mass enhancements. ResultsFor mass enhancements (ME), multimodal ultrasound demonstrated strong efficacy (AUC = 0.8651, 95% CI: 0.7431 to 0.9871), exhibiting high sensitivity (83.3%) and specificity (92.4%) in differentiating IGM from breast cancer. However, for non-mass enhancements (NME), multimodal ultrasound showed limited accuracy (AUC = 0.6306) with lower sensitivity (65.6%) and specificity (81.2%) in distinguishing between IGM and breast cancer. ConclusionMultimodal ultrasound displayed good diagnostic efficacy for mass enhancements in DCE-MRI for idiopathic granulomatous mastitis and breast cancer, while for non-mass enhancement patterns, DCE-MRI remains the most valuable radiological modality for comprehensively assessing this condition's complexities.

Comparative Analysis of Nomogram and Machine Learning Models for Predicting Axillary Lymph Node Metastasis in Early-Stage Breast Cancer: A Study on Clinically and Ultrasound-Negative Axillary Cases Across Two Centers

ObjectiveEarly and accurate prediction of axillary lymph node metastasis (ALNM) is crucial in determining appropriate treatment strategies for patients with early-stage breast cancer. The aim of this study was to evaluate the efficacy of radiomic features extracted from ultrasound (US) images combined with machine learning (ML) methods in predicting ALNM to improve diagnostic accuracy and patient prognosis. MethodsIn this retrospective study, data of 282 early-stage breast cancer patients from two centers were analyzed. We considered clinicopathological characteristics, conventional US features, contrast-enhanced ultrasound (CEUS) characteristics, and radiomics features. Radiomics features were extracted from US images, and using least absolute shrinkage and selection operator (LASSO) regression, 12 key features were selected to compute a Radiomics score (Rad-score). A nomogram was developed based on these features, alongside five ML models: Logistic Regression (LR), Naive Bayes (NB), Support Vector Machine (SVM), K-Nearest Neighbors (KNN), and Extreme Gradient Boosting (XGBoost). Model performance was evaluated using metrics such as the area under the curve (AUC), accuracy (ACC), sensitivity (SEN), specificity (SPE), negative predictive value (NPV), and positive predictive value (PPV). ResultsBoth the nomogram and ML models, including the Rad-score combined with histologic type, significantly predicted ALNM. Among all models, the XGBoost model showed the best performance with an AUC of 0.810 and an accuracy of 84.1% in the external test set, surpassing the nomogram and other ML models. SHapley Additive exPlanations (SHAP) analysis further provided insights into the influence of individual radiomics features on ALNM prediction. ConclusionsWhile the nomogram provides a useful traditional statistical approach, integrating radiomics features with ML, particularly the XGBoost model enhanced by SHAP interpretability, offers superior predictive accuracy for ALNM in early-stage breast cancer patients.

Development of an inhalable contrast agent targeting the respiratory tract mucus layer for pulmonary ultrasonic imaging

Impaired mucociliary transport is a distinguishing sign of cystic fibrosis, but current methods of evaluation are invasive or expose young patients to ionizing radiation. Contrast-enhanced ultrasound imaging may provide a feasible alternative. We formulated a cationic microbubble ultrasound contrast agent, to optimize adhesion to the respiratory mucus layer when inhaled. Potential toxicity was evaluated in human bronchial epithelial cell (hBEC) cultures following a 24-hour exposure, compared to positive and negative control conditions. In vivo tolerability and pulmonary image enhancement feasibility were evaluated in mice, comparing oropharyngeal administration of contrast agent to saline control. When induced to flow across mucus plated on microscope slides, cationic microbubbles demonstrated greater affinity for target samples than standard microbubbles. Cationic microbubbles elicited no proinflammatory or cytotoxic response in hBECs, nor were any cross-links to the cilia observed. Unlike standard microbubbles, cationic microbubbles mixed into the mucus layer, without epithelial absorption, and were observed to move with the mucus layer by the action of mucociliary transport. When administered to mice, cationic microbubbles enhanced sonographic visualization of the trachea, and were well-tolerated with no adverse effects. This developmental work supports the safety and feasibility of a mucus-targeting contrast agent that may be useful for pulmonary ultrasound applications.

Cerebral, Splanchnic, and Renal Transit Time Measurement and Blood Volume Estimation Using Contrast-Enhanced Ultrasonography.

We aimed to measure cerebral, splanchnic, and renal transit times and the associated blood volumes using contrast ultrasound. In healthy individuals, regional transit times were calculated from time-intensity curves generated as ultrasound contrast passed through the associated inflow and outflow vessels. These included the internal carotid artery and internal jugular vein (brain), the superior mesenteric artery and portal vein (intestines), and the renal artery and renal vein (kidney). An organ's blood volume relative to the stroke volume delivered to that organ with each cardiac cycle was calculated from the product of heart rate and transit time of contrast passage through the associated vascular bed. The fraction of systemic stroke volume received by each organ was calculated from the respective velocity-time integral and inflow vessel cross-sectional area and used to estimate absolute organ blood volume. The cohort consisted of 16 participants (age: 42 ± 13 years; 5 female) without known cerebrovascular, gastrointestinal, or renal disease. Cerebral, splanchnic, and renal transit times were obtained for 15, 14, and 8 individuals, respectively. Anatomic variability of the renal vessels confounded the acquisition of renal transit times. For all organs, transit times were reproducible and the associated blood volumes were generally comparable to reference values. Cerebral, gastrointestinal, and renal transit times/blood volumes can be reasonably acquired from contrast ultrasound, although the latter is less reliably available. Assessment of the impact on regional blood volumes of pharmacologic or other interventions is a next step toward clinical application of this technique.

Contrast-enhanced US Bosniak Classification: intra- and inter-rater agreement, confounding features, and diagnostic performance

BackgroundThe contrast-enhanced US (CEUS) Bosniak classification, proposed by the European Federation for Ultrasound in Medicine and Biology (EFSUMB) in 2020, predicts malignancy in cystic renal masses (CRMs). However, intra- and inter-rater reproducibility for CEUS features has not been well investigated.PurposeTo explore intra- and inter-rater agreement for US features, identify confounding features, and assess the diagnostic performance of CEUS Bosniak classification.Materials and methodsThis retrospective study included patients with complex CRMs who underwent CEUS examination from January 2013 to August 2023. Radiologists (3 experts and 3 novices) evaluated calcification, echogenic content, wall, septa, and internal nodules of CRMs using CEUS Bosniak classification. Intra- and inter-rater agreements were assessed using the Gwet agreement coefficient (Gwet’s AC). Linear regression identified features associated with discrepancies in Bosniak category assignment. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUC).ResultsA total of 103 complex CRMs were analyzed in 103 patients (mean age, 50 ± 15 years; 66 males). Intra-rater agreement for the Bosniak category was substantial to almost perfect (Gwet’s AC 0.73–0.87). Inter-rater agreement was substantial for the Bosniak category (Gwet’s AC 0.75) and moderate to almost perfect for US features (Gwet’s AC 0.44–0.94). Nodule variation (i.e., absence vs. obtuse margin vs. acute margin) explained 84% of the variability in the Bosniak category assignment. CEUS Bosniak classification showed good diagnostic performance, with AUCs ranging from 0.78 to 0.90 for each rater.ConclusionsCEUS Bosniak classification demonstrated substantial intra- and inter-rater reproducibility and good diagnostic performance in predicting the malignancy potential of CRMs. Nodule variations significantly predicted differences in Bosniak category assignments.Critical relevance statementContrast-enhanced US Bosniak classification reliably predicts malignancy in cystic renal masses, demonstrating substantial reproducibility and diagnostic accuracy. This improves clinical decision-making and patient management.Key PointsIntra- and inter-rater reproducibility for contrast-enhance US features for Bosniak classification have not been well investigated.Substantial inter-rater agreements for the Bosniak category and variable agreements for determining imaging features were found.Contrast-enhanced US Bosniak classification is reproducible and has good diagnostic performance for predicting malignancy in cystic renal masses.Graphical

Microwave ablation for benign thyroid nodules with cosmetic problems and related factors for post-ablative complete relief: a two-center retrospective study.

To investigate the efficacy of ultrasound (US)-guided percutaneous MWA for benign thyroid nodules with cosmetic problems and identify related factors contributing to post-ablative complete relief (CR). This retrospective study reviewed the efficacy of MWA in treating thyroid nodules in patients with cosmetic problems who underwent MWA from January 2021 to May 2023. Patients were followed up at 1, 3, and 6 months after MWA. Pre-treatment clinical characteristics, conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) features were analyzed to explore their correlation with cosmetic improvement, defined as a cosmetic score of 1 or 2 at the 6-month follow-up. Univariable and multivariable regression analyses were carried out to identify variables associated with CR, and the related nomogram was established. Calibration curve and decision curve analysis were used to evaluate the nomogram performance. 118 patients with 118 nodules were included in the study. During the 1-, 3- and 6-month follow-up, the mean volume reduction ratios (VRR) were 2%, 36% and 73%, respectively. 22.0% (26/118), 57.6% (68/118), and 89.8% (106/118) patients achieved CR of cosmetic problems at 1, 3, and 6 months after MWA. In multivariable analysis, three variables (i.e., non-hashimoto's thyroiditis [HT] [OR: 90.036, P = 0.001], nodule location not close to danger triangle area [OR: 66.812, P = 0.003], early hyperenhancement on CEUS [OR: 0.035, P = 0.024]) were found to be closely associated with CR of cosmetic problems at 6 months after MWA. A nomogram model was constructed, and its accuracy was well validated (i.e., C-index = 0.914). MWA was effective and safe for treating benign thyroid nodules with cosmetic problems. Non-HT, nodule location not close to danger triangle area, and early hyperenhancement on CEUS were associated with CR of cosmetic problems after MWA.

The value and sensitivity of contrast-enhanced ultrasonography combined with fine-needle aspiration biopsy in the diagnosis of thyroid nodules

To investigate the value and sensitivity of contrast-enhanced ultrasonography (CEUS) combined with fine-needle aspiration biopsy (FNAB) in the diagnosis of thyroid nodules. This study enrolled 120 patients with thyroid nodules who visited our hospital between July 2018 and January 2021. All patients underwent CEU and CEUS-guided FNAB. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CEUS-guided FNAB for the qualitative diagnosis of thyroid nodules were significantly higher compared with CEUS only (P < 0.05). The consistency in the diagnostic results was high between CEU-guided FNAB and surgical pathology and moderate between CEU and surgical pathology. The diagnostic coincidence rates of CEUS-guided FNAB were significantly higher than those of CEU only for papillary thyroid carcinoma, follicular carcinoma, undifferentiated carcinoma, and medullary carcinoma (P < 0.05). The diagnostic coincidence rates of CEUS-guided FNAB for stages I, II, and III thyroid cancer were significantly higher compared with CEU only (P < 0.05). Contrast-enhanced ultrasonography combined with FNAB improved the sensitivity and accuracy of making a qualitative diagnosis for thyroid nodules. This outcome will not only help to distinguish thyroid cancer from benign ones but can also assist in determining the pathological type and tumor stage of thyroid cancer, thereby presenting good diagnostic value.

Contrast-enhanced ultrasonography guidance avoids US-CT/MR fusion error for percutaneous radiofrequency ablation of hepatocellular carcinoma

BackgroundThis study evaluated the impact of contrast-enhanced ultrasonography (CEUS) combined with CT or MRI fusion imaging on percutaneous radiofrequency ablation (RFA) outcomes for hepatocellular carcinoma (HCC) inconspicuous on conventional ultrasonography (US).MethodsPatients were categorized into US-inconspicuous (USI) and US-conspicuous (USC) groups based on US imaging. The parameters of viable HCCs ⎯ including diameter, location, and RFA efficacy ⎯ were compared between USI and USC groups. Moreover, the breathing fusion imaging errors were measured. The differences in technical success, technical efficacy, local tumor progression, new tumor occurrence, and overall survival rate between USI and USC groups were analyzed.ResultsSixty-five patients with 106 lesions were included. CEUS showed high consistency with CT/MRI but revealed larger diameters (p < 0.001) and more feeding arteries (p = 0.019) than CT/MRI. Breathing fusion imaging errors averaged 17 ± 4 mm, significantly affecting lesions in segments II, III, V, and VI (p < 0.001). The USI group had more lesions ablated per patient in a single RFA procedure (p = 0.001) than the USC group. No significant differences were observed in technical success rate, technical efficacy rate, local tumor progression rate, and overall survival rate between the two groups.ConclusionsCEUS combined with fusion imaging provides detailed information on viable HCCs and their feeding arteries. CEUS-guided RFA avoids fusion imaging errors and achieves comparable efficacy in both US-conspicuous and US-inconspicuous HCCs.

Correlation of dynamic contrast-enhanced ultrasonography and the Ki-67 labelling index in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant and aggressive tumor, and high Ki-67 expression indicates poor histological differentiation and prognosis. Therefore, one of the challenges in diagnosing preoperatively patients with PDAC is predicting the degree of malignancy. Dynamic contrast-enhanced ultrasonography (DCE-US) plays a crucial role in abdominal tumor diagnosis, and can adequately show the microvascular composition within the tumors. However, the relationship between DCE-US and the Ki-67 labelling index remains unclear at the present time. To predict the correlation between Ki-67 expression and the parameters of DCE-US. Patients with PDAC who underwent DCE-US were retrospectively analyzed. Patients who had received any treatment (radiotherapy or chemotherapy) prior to DCE-US; had incomplete clinical, imaging, or pathologic information; and had poor-quality image analysis were excluded. Correlations between Ki-67 expression and the parameters of DCE-US in patients with PDAC were assessed using Spearman's rank correlation analysis. The diagnostic performances of these parameters in high Ki-67 expression group were evaluated according to receiver operating characteristic curve. Based on the Ki-67 labelling index, 30 patients were divided into two groups, i.e., the high expression group and the low expression group. Among the relative quantitative parameters between the two groups, relative half-decrease time (rHDT), relative peak enhancement, relative wash-in perfusion index and relative wash-in rate were significantly different between two groups (P = 0.018, P = 0.025, P = 0.028, P = 0.035, respectively). The DCE-US parameter rHDT was moderately correlated with Ki-67 expression, and rHDT ≥ 1.07 was more helpful in accurately diagnosing high Ki-67 expression, exhibiting a sensitivity and specificity of 53.8% and 94.1%, respectively. One parameter of DCE-US, rHDT, correlates with high Ki-67 expression. It demonstrates that parameters obtained noninvasively by DCE-US could better predict Ki-67 expression in PDAC preoperatively.

Can preoperative percutaneous injection of ultrasound contrast agent locate sentinel lymph nodes of breast cancer?

ObjectivesWe evaluated the ability and accuracy of preoperative identification and localization of sentinel lymph nodes (SLNs) using intradermal injection of ultrasound contrast agent.Materials and methodsProspectively recruited 191 early breast cancer patients with clinically negative axillary lymph nodes (ALNs). All participants received intradermal injection of microbubble contrast agent. Following the identification and localization of SLNs using contrast-enhanced ultrasound (CEUS), Markers were deployed in the SLNs US-guided. Subsequently, the SLNs with Markers were stained and marked with a suspension of nano-carbon US-guided to assist in intraoperative localization of SLNs. Standard SLNB with methylene blue tracing was performed intraoperatively to assess the consistency between the two methods of SLNs localization, thereby determining the ability and accuracy of CEUS in identifying and localizing SLNs.ResultsA total of 179 patients were included in the final evaluation analysis, in which a microbubble contrast agent was injected subcutaneously in the areolar region. A total of 201 SLNs were identified, with a median of 1 SLN per patient. Each SLN was identified in 157 patients, and two SLNs were identified in 22 patients. Among the 201 SLNs from the 179 patients, the proportion that could be individually matched between CEUS and the blue dye method was 95.5% (192/201), and the consistency evaluation in SLNs identification between CEUS and blue dye staining was excellent (Kappa value = 0.62, P &amp;lt; 0.001).ConclusionThe consistency of identification and localization of SLNs in early breast cancer patients between CEUS and the blue dye method was strong.

The diagnositic value of dynamic contrast-enhanced ultrasound for evaluation of tissue oxygen status in rat hepatoma model

BackgroundHypoxia is a characteristic of solid tumors, but whether significant hypoxia exists in the hepatocellular carcinoma remains unclear. This animal study aims to explore the value of dynamic contrast-enhanced ultrasound (CEUS) quantitative parameters to evaluate the oxygen status in two rat hepatoma models.Materials and methodsN1S1 and McA-RH7777 S-D rat orthotopic hepatoma models were established. Once the tumors reached a diameter of 10–15 mm, CEUS and oxygen partial pressure (pO2) polarography were performed. Immunohistochemical staining for HIF-1α and pimonidazole was conducted after euthanizing the rats. Correlation between quantitative CEUS parameters, pO2, and the immunohistochemical integrated optical density (IOD) was analyzed to assess the predictive ability of CEUS quantitative parameters for the tissue oxygen environment.ResultEleven N1S1 models and ten McA-RH7777 models were established successfully. There was no significant difference in pO2 (35.5 mmHg vs 32.2 mmHg, P = 0.917), IOD of HIF-1α (13.4 vs 20.0, P = 0.159) and pimonidazole (0.70 vs 1.30, P = 0.926) between the tumor and the peritumoral liver tissue. The pO2 values were correlated with CEUS quantitative parameters including mean time-intensity curves (mTIC) (P = 0.003), peak intensity (PKI) (P = 0.010), area under the curve (AUC) (P = 0.009), area under the wash-in curve (WiAUC) (P = 0.006), and arrival time (AT) (P = 0.033). The IOD of HIF-1α correlated with AUC (P = 0.022), WiAUC (P = 0.009), ascending slope (AS) (P = 0.044), and falling time (FT) (P = 0.009). Multiple linear regression indicated that the “short AT” was an independent protective factor for hypoxia (β = -2.347, 95% CI: -4.948, -0.394, P = 0.022), and CEUS had the ability to predict the tumor pO2 (P = 0.003).ConclusionNo evidence of significant hypoxia was identified in two rat orthotopic hepatoma models. Quantitative CEUS parameters correlated with the oxygen status of the tumor, which could be utilized to predict the tumor tissue pO2.

Comparison of contrast-enhanced ultrasound imaging (CEUS) and super-resolution ultrasound (SRU) for the quantification of ischaemia flow redistribution: a theoretical study

The study of microcirculation can reveal important information related to pathology. Focusing on alterations that are represented by an obstruction of blood flow in microcirculatory regions may provide an insight into vascular biomarkers. The current in silico study assesses the capability of contrast enhanced ultrasound (CEUS) and super-resolution ultrasound imaging (SRU) flow-quantification to study occlusive actions in a microvascular bed, particularly the ability to characterise known and model induced flow behaviours. The aim is to investigate theoretical limits with the use of CEUS and SRU in order to propose realistic biomarker targets relevant for clinical diagnosis. Results from CEUS flow parameters display limitations congruent with prior investigations. Conventional resolution limits lead to signals dominated by large vessels, making discrimination of microvasculature specific signals difficult. Additionally, some occlusions lead to weakened parametric correlation against flow rate in the remainder of the network. Loss of correlation is dependent on the degree to which flow is redistributed, with comparatively minor redistribution correlating in accordance with ground truth measurements for change in mean transit time,dMTT(CEUS,R = 0.85; GT,R = 0.82) and change in peak intensity,dIp(CEUS,R = 0.87; GT,R = 0.96). Major redistributions, however, result in a loss of correlation, demonstrating that the effectiveness of time-intensity curve parameters is influenced by the site of occlusion. Conversely, results from SRU processing provides accurate depiction of the anatomy and dynamics present in the vascular bed, that extends to individual microvessels. Correspondence between model vessel structure displayed in SRU maps with the ground truth was>91%for cases of minor and major flow redistributions. In conclusion, SRU appears to be a highly promising technology in the quantification of subtle flow phenomena due ischaemia induced vascular flow redistribution.

The Value of Necrotic Area Features in Contrast-Enhanced Ultrasound for Distinguishing Between Benign and Malignant Subpleural Pulmonary Lesions

ObjectiveTo analyze Necrotic Area Features of subpleural pulmonary lesions (SPLs) demonstrated by contrast-enhanced ultrasound (CEUS) and investigate their value in differentiating between malignant and benign SPLs. MethodsPatients with SPLs who underwent CEUS at our hospital from January to May 2021. The following patient information was recorded: (i) age, (ii) sex, (iii) lesion size, (iv) lesion location, (v) size of necrotic areas and (vi) necrotic area morphology, including sieve-like necrosis, necrotic area with septal enhancement, necrotic area with annular enhancement margins, and necrotic area with burr-like enhancement margins. These parameters were analyzed using univariate and multivariate logistic regression. Subgroup analyses based on lesion size were further conducted using the collected data. ResultsA total of 212 patients with 212 SPLs were enrolled, comprising 99 benign and 113 malignant cases. Significant differences were observed between malignant and benign groups in terms of age, sex, lesion size and necrotic area morphology (all, p < 0.05). ConclusionNecrotic area's features observed on CEUS were valuable for distinguishing between benign and malignant SPLs. Age, sex, lesion size and the presence of burr-like enhancement margins are identified as independent predictors of malignant lesions.

Assessing Therapeutic Nanoparticle Accumulation in Tumors Using Nanobubble-Based Contrast-Enhanced Ultrasound Imaging.

This study explores the challenges associated with nanoparticle-based drug delivery to the tumor parenchyma, focusing on the widely utilized enhanced permeability and retention effect (EPR). While EPR has been a key strategy, its inconsistent clinical success lacks clear mechanistic understanding and is hindered by limited tools for studying relevant phenomena. This work introduces an approach that employs multiparametric dynamic contrast-enhanced ultrasound (CEUS) with a nanoscale contrast agent for noninvasive, real-time examination of tumor microenvironment characteristics. We demonstrate that CEUS imaging can: (1) evaluate tumor microenvironment features, (2) be used to help predict the distribution of doxorubicin-loaded liposomes in the tumor parenchyma, and (3) be used to predict nanotherapeutic efficacy. CEUS using nanobubbles (NBs) was carried out in two tumor types of high (LS174T) and low (U87) vascular permeability. LS174T tumors consistently showed significantly different time intensity curve (TIC) parameters, including area under the rising curve (AUCR, 2.7×) and time to peak intensity (TTP, 1.9×) compared to U87 tumors. Crucially, a recently developed decorrelation time (DT) parameter specific to NB CEUS dynamics successfully predicted the distribution of doxorubicin-loaded liposomes within the tumor parenchyma (r = 0.86 ± 0.13). AUCR, TTP, and DT were used to correlate imaging findings to nanotherapeutic response with 100% accuracy in SKOV-3 tumors. These findings suggest that NB-CEUS parameters can effectively discern tumor vascular permeability, serving as a biomarker for identifying tumor characteristics and predicting the responsiveness to nanoparticle-based therapies. The observed differences between LS174T and U87 tumors and the accurate prediction of nanotherapeutic efficacy in SKOV-3 tumors indicate the potential utility of this method in predicting treatment efficacy and evaluating EPR in diseases characterized by pathologically permeable vasculature. Ultimately, this research contributes valuable insights into refining drug delivery strategies and assessing the broader applicability of EPR-based approaches.

Towards reliable subharmonic-aided pressure estimation: Simulation and experimental validation of microbubble dynamics

This study examines the reliability of subharmonic-aided pressure estimation (SHAPE) using polydisperse microbubbles. SHAPE utilizes the subharmonic response of ultrasound contrast agent microbubbles to estimate pressure non-invasively. Despite its potential, gaps in theoretical understanding and experimental inconsistencies with polydisperse microbubbles necessitate further investigation. This research explores the impact of microbubble distribution, excitation parameters, and contrast-enhanced ultrasound imaging modes on SHAPE’s signal consistency, measurement linearity, and sensitivity. A one-dimensional microbubble population model was developed to simulate microbubble behavior and the Hilbert transform demodulation technique was applied for subharmonic analyses. Variability in SHAPE was further assessed through flow phantom experiments using Sonazoid agents and a commercial SHAPE scanner. Findings indicate that bubble distribution in both size and location, microbubble interactions, and CEUS imaging modes significantly influence subharmonic responses. An excitation frequency of 3.5 MHz is recommended for robust SHAPE. Monte Carlo simulations confirmed the inherent variability of subharmonic amplitude signals due to dynamic bubble distributions. Using monodisperse microbubbles enhanced SHAPE sensitivity and consistency, without markedly reducing signal variability. These results underscore the necessity of further research to optimize SHAPE for clinical applications, focusing on microbubble characteristics and excitation conditions to enhance consistency and reliability.

Incremental clinical value of intraplaque neovascularization in predicting recurrent ischemic stroke.

Carotid intraplaque neovascularization (IPN) detected by contrast-enhanced ultrasound (CEUS) is a risk factor for recurrent ischemic stroke. However, it is still unclear whether IPN can be used to accurately identify patients with recurrent ischemic stroke in clinical practice. Herein, we investigated the clinical predictive value of IPN for recurrent ischemic stroke in a real-world setting. We enrolled 200 patients with ischemic stroke and atherosclerotic carotid stenosis who were followed up for 2 years. The endpoint was recurrent ischemic stroke. Cox regression and subgroup analyses were employed to assess whether treatment affected the relationship between IPN and recurrent ischemic stroke. The net classification index (NRI) and integrated discriminant improvement index (IDI) were used to validate the additional clinical value of IPN in identifying recurrent ischemic stroke. During the 2-year follow-up, 36 patients experienced recurrent ischemic stroke. Cox regression analyses showed that IPN (grade 2), hypoechoic plaque, high homocysteine levels, and smoking were independent risk factors for recurrent ischemic stroke. Additional IPN evaluation may increase the NRI (0.512; 95% confidence interval [CI]: 0.083-0.624) and IDI (0.151; 95% CI: 0.010-0.213) for identifying high-risk patients with recurrent ischemic stroke. In addition, in the subgroup undergoing revascularization, the proportion of IPN (grade 2) was significantly higher in patients with recurrent ischemic stroke than in patients with nonrecurrent ischemic stroke (p = 0.001). In clinical settings, IPN, assessed by CEUS, may provide additional clinical value for predicting recurrent ischemic stroke, helping to identify patients with ischemic stroke who require close follow-up.

Ceus features of liver pecoma: a case report and literature review.

Perivascular epithelioid cell neoplasms (PEComas) and epithelioid angiomyolipomas (EAMLs) are two different denominations for the same "mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells". Hepatic PEComa/EAML is a very rare neoplasm, and only 29 case reports of hepatic PEComa and 25 of hepatic EAML have been reported in the current literature. A clear female predominance with a mean age at diagnosis of 42.5years old can be observed by literature review. Ultrasound (US) examination was the first-line diagnostic technique in most of the cases of hepatic PEComa, but it was documented in very few cases of hepatic EAML. A great variability in the ultrasonographic B-mode, color Doppler and contrast-enhanced ultrasonography (CEUS) features of hepatic PEComa/EAML emerges. Computed tomography and magnetic resonance were the most common used techniques to confirm the nature of the hepatic lesion, even if the anatomo-pathological examination was the only technique to display a certainty diagnosis and to differentiate hepatic PEComa/EAML from benign and malignant hepatic lesions. The great majority of hepatic PEComas/EAMLs are surgically treated without any adjuvant therapy.