High frame-rate contrast enhanced ultrasound (HIFR-CEUS) in the characterization of small hepatic lesions in cirrhotic patients

High-frequency contrast-enhanced ultrasound in discriminating benign and malignant superficial lymph nodes: a diagnostic comparison

BACKGROUND

Lymph nodes are critical immune system components, filtering harmful substances and acting as indicators in various disease states, including cancer. Accurate differentiation between benign and malignant superficial lymph nodes is essential for diagnosis and treatment planning. However, conventional diagnostic methods often lack the required precision. High-frequency contrast-enhanced ultrasound (H-CEUS) offers improved temporal resolution and visualization of microvascular structures, potentially providing better diagnostic accuracy than standard contrast-enhanced ultrasound (CEUS).

METHODS

This study included 77 patients with suspected abnormalities in superficial lymph nodes. Each patient underwent H-CEUS and CEUS examinations, with diagnoses confirmed through biopsy or surgical resection. The diagnostic performance of H-CEUS and CEUS was evaluated using sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Chi-square tests and ROC curve analysis were employed to compare the efficacy of H-CEUS and CEUS in differentiating benign from malignant lymph nodes.

RESULTS

H-CEUS demonstrated superior diagnostic performance over CEUS, with higher sensitivity (95.92% vs. 83.67%), specificity (92.86% vs. 57.14%), and accuracy (94.80% vs. 74.03%). H-CEUS enhanced microvascular morphology visualization, facilitating more accurate differentiation between benign and metastatic lymph nodes. The area under the ROC curve for H-CEUS (0.944) was significantly greater than that for CEUS (0.704), indicating improved diagnostic capability.

CONCLUSION

H-CEUS offers enhanced accuracy in diagnosing the nature of superficial lymph nodes, potentially improving clinical decision-making for patients with suspected lymph node malignancies. These findings support the integration of H-CEUS into routine clinical practice to achieve better diagnostic outcomes.

Diagnostic value of high-frame-rate contrast-enhanced ultrasound and contrast vector imaging for superficial lymph node lesions

PURPOSE

To explore the diagnostic performance and feasibility of high-frame-rate contrast-enhanced ultrasound (HFR CEUS) combined with contrast vector imaging (CVI) in detecting benign and malignant superficial lymph nodes (SLNs).

MATERIALS AND METHODS

In this single-center prospective study conducted between October 2023 and February 2024, 38 consecutive patients with suspected SLN lesions underwent B-mode US, HFR CEUS examination, and post-processing CVI analysis. Their diagnosis was confirmed using fine-needle aspiration cytologic or histopathologic examination. The diagnostic efficacy of HFR CEUS alone and the combination of HFR CEUS with CVI for benign and malignant LN diagnosis was compared and the significance of other CVI parameters was evaluated.

RESULTS

The final data set included 38 participants (mean age, 56 ± 16 years) with 42 SLN lesions. Both HFR CEUS alone and HFR CEUS combined with CVI examination showed differences in the contrast patterns of benign and malignant SLNs (all P < 0.001). The contrast pattern of benign LNs was predominantly centrifugal, while that of malignant LNs was primarily centripetal and hybrid and they were more likely to exhibit perfusion defects. The comparison between CVI combined with HFR CEUS examination and pathological results for the diagnosis of benign and malignant LNs showed a high level of consistency with a kappa value of 0.81. Comparison with HFR CEUS alone resulted in a kappa value of 0.66.

CONCLUSION

HFR CEUS combined with CVI examination demonstrated a good performance in distinguishing benign and malignant SLNs.

Demonstration of Hepatic Vein Abnormalities Using Contrast-Enhanced Sonography in Liver Diseases

Contrast-enhanced US (CEUS) is now widely used to observe the hemodynamics of the liver. The CEUS diagnosis mainly consists of evaluating hepatic artery and portal vein flow changes in liver diseases, but it has not been widely used for the diagnosis of hepatic venous (HV) abnormalities in the clinical setting. For this background, this review tried to reconsider this problem. In short, observing HV CEUS findings, especially HV transit time, serves to largely narrow the differential diagnosis and increase the diagnostic confidence of the CEUS. However, diagnosing HV CEUS diagnosis in a wide range of liver diseases requires understanding of vascular anatomy of the upper abdomen and vascular structure of each disease. Additionally, interpreting CEUS findings of HCC should be prudent, because its drainage vessels change according to the histological progression, from the HV to the portal vein. Thus, the most important way of making use of the CEUS information is interpreting it in conjunction with the clinical data.

Relationship between contrast-enhanced ultrasound combined with ultrasound resolution microscopy imaging and histological features of hepatocellular carcinoma

OBJECTIVES

Using contrast-enhanced ultrasound (CEUS) and ultrasound resolution microscopy (URM) imaging, this study aimed to evaluate the relationship between microvascular parameters of small hepatocellular carcinoma (sHCC) (≤ 3 cm) and microscopic histological features, which include vessels encapsulating tumour clusters (VETC), microvascular invasion (MVI), and histological grade.

METHODS

Sixteen patients with solitary resected sHCC were prospectively enrolled. CEUS and URM were performed one week before resection. All "ratio" refers to comparisons between the active area (where CEUS microbubble show visible motion track by URM) and the entire lesion. Blood vessel complexity (ratio), blood vessel density (ratio), area (ratio), flow velocity, blood vessel diameter, and perfusion index ("flow velocity" × "vessel ratio") were analysed using URM. The relationships between URM parameters and microscopic histological features (MVI, VETC, and histological grade) were analysed.

RESULTS

There were 5 (31.3%), 8 (50%), and 7 (43.7%) cases of poorly differentiated, MVI-positive, and VETC-positive HCC, respectively. The mean velocity of the entire lesion was higher in the poorly differentiated group than that in the moderately differentiated group (p = 0.026). The complexity ratio (MVI-positive: 1.07 ± 0.03, MVI-negative: 1.03 ± 0.02, p = 0.012), area ratio (MVI-positive: 0.63 ± 0.18, MVI-negative: 0.39 ± 0.16, p = 0.017), and perfusion index (MVI-positive: 8.67 ± 1.88, MVI-negative: 6.42 ± 0.94, p = 0.009) were greater in MVI-positive HCCs. The density ratio (VETC-positive: 1.30 ± 0.19, VETC-negative: 1.10 ± 0.05, p = 0.006) was larger in VETC-positive HCCs.

CONCLUSION

Higher blood flow velocity and area of HCC lesions, and higher blood vessel complexity and density may be related to microscopic histological features. This relationship might provide a strategy of using URM for preoperative non-invasive diagnostic VETC, MVI, and histological grade in the future.

Contrast-Enhanced Sonography of the Liver: How to Avoid Artifacts

Contrast-enhanced sonography (CEUS) is a very important diagnostic imaging tool in clinical settings. However, it is associated with possible artifacts, such as B-mode US-related artifacts. Sufficient knowledge of US physics and these artifacts is indispensable to avoid the misinterpretation of CEUS images. This review aims to explain the basic physics of CEUS and the associated artifacts and to provide some examples to avoid them. This review includes problems related to the frame rate, scanning modes, and various artifacts encountered in daily CEUS examinations. Artifacts in CEUS can be divided into two groups: (1) B-mode US-related artifacts, which form the background of the CEUS image, and (2) artifacts that are specifically related to the CEUS method. The former includes refraction, reflection, reverberation (multiple reflections), attenuation, mirror image, and range-ambiguity artifacts. In the former case, the knowledge of B-mode US is sufficient to read the displayed artifactual image. Thus, in this group, the most useful artifact avoidance strategy is to use the reference B-mode image, which allows for a simultaneous comparison between the CEUS and B-mode images. In the latter case, CEUS-specific artifacts include microbubble destruction artifacts, prolonged heterogeneous accumulation artifacts, and CEUS-related posterior echo enhancement; these require an understanding of the mechanism of their appearance in CEUS images for correct image interpretation. Thus, in this group, the most useful artifact avoidance strategy is to confirm the phenomenon's instability by changing the examination conditions, including the frequency, depth, and other parameters.

Contrast-Enhanced Ultrasound in the Diagnosis of Solid Renal Lesions

The availability of imaging methods has enabled increased detection of kidney lesions, which are a common clinical problem. It is estimated that more than half of patients over the age of 50 have at least one undetermined mass in the kidney. The appropriate characterization and diagnosis of lesions imaged in the kidney allows for proper therapeutic management. Previously, contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) have been used in their extended diagnosis. However, the limitations of these techniques, such as radiation exposure, renal toxicity, and allergies to contrast agents, must be considered. Contrast-enhanced ultrasound (CEUS) is increasingly being used as an examination to resolve interpretive doubts that arise with other diagnostic methods. Indeed, it can be considered both as a problem-solving technique for diagnosing and distinguishing lesions and as a technique used for observation in preservative treatment. Evaluation of the enhancement curve over time on CEUS examination can help to differentiate malignant renal cell carcinoma (RCC) subtypes that should be resected from benign lesions, such as oncocytoma or angiomyolipoma (AML), in which surgery can be avoided. It allows for distinguishing between benign and malignant tumors, renal and pseudotumors, and solid and cystic tumors. Therefore, with recent advances in ultrasound technology, CEUS has emerged as a fast, reliable, and cost-effective imaging tool in the preoperative evaluation and diagnosis of solid renal masses.

High-frame-rate contrast-enhanced ultrasound to differentiate between clear cell renal cell carcinoma and angiomyolipoma

BACKGROUND

To investigate the diagnostic efficacy of high-frame-rate contrast-enhanced ultrasound (H-CEUS) in differentiating between clear cell renal cell carcinoma (CCRCC) and angiomyolipoma (AML).

METHODS

A retrospective study was performed on the clinical data of 79 patients diagnosed with CCRCC and 31 patients diagnosed with AML at the First Affiliated Hospital of Nanchang University between October 2022 and December 2023. Conventional ultrasound (US) and H-CEUS examinations were conducted on all patients prior to surgery, dynamic images were recorded from the US, and the qualitative and quantitative parameters of H-CEUS were collected. The t-test, χ² test and non-parametric Mann-Whitney test were employed to assess differences in clinical data, US characteristics, and qualitative and quantitative parameters of H-CEUS between the CCRCC and AML groups. The independent risk factors of CCRCC were identified using binary logistic regression. The receiver operator characteristic (ROC) curve was constructed to evaluate the diagnostic effectiveness of clinical + US and H-CEUS in differentiating between CCRCC and AML.

RESULTS

The CCRCC group and the AML group exhibited significant differences in patient gender, operation mode, nodular echo, and nodule blood flow (χ²=11.698, -, -,=10.582; P<0.001, <0.001, <0.001, and = 0.014, respectively). In addition, the H-CEUS qualitative analysis demonstrated significant differences between the AML group and the CCRCC group with respect to enhancement mode, regression mode, peak intensity, enhancement uniformity, no enhancement, and presence or absence of pseudocapsule (χ²=41.614, -, -, = 2.758, = 42.099, -; P<0.001, <0.001, <0.001, 0.097, <0.001, and <0.001, respectively). The Arrival time (AT) in the CCRCC group was significantly shorter than that in the AML group, as determined by quantitative analysis of H-CEUS (Z=-3.266, P = 0.001). Furthermore, the Peak intensity (PI), Ascent slope (AS), and The area under the curve (AUC) exhibited significantly higher values in the CCRCC group compared to the AML group (Z=-2.043,=-2.545,=-3.565; P = 0.041, = 0.011, and <0.001, respectively). Logistic regression analysis indicated that only gender, nodule echo, the pseudocapsule, AS, and AUC of H-CEUS were independent risk factors of CCRCC. The ROC curve revealed that combining gender and nodule echo yielded a sensitivity of 92.4%, specificity of 64.5%, and an AUC of 0.847 in distinguishing between CCRCC and AML. When combining the H-CEUS parameters of pseudocapsule, AS, and AUC, the sensitivity, specificity, and AUC for distinguishing between CCRCC and AML were 84.8%, 96.8%, and 0.918, respectively. No statistically significant difference was observed in the diagnostic effectiveness of the two methods (Z=-1.286, P = 0.198). However, H-CEUS demonstrated better AUC and specificity.

CONCLUSIONS

H-CEUS enhances the sensitivity and specificity of differentiating between CCRCC and AML by improving the temporal resolution, offering a more precise diagnostic foundation for identifying the most appropriate therapy for patients.

Characteristics of high frame frequency contrast-enhanced ultrasound in renal tumors

OBJECTIVE

This study aims to analyze the characteristics of high frame rate contrast-enhanced ultrasound (H-CEUS) in renal lesions and to improve the ability for differential diagnosis of renal tumors.

METHODS

A total of 140 patients with renal lesions underwent contrast-enhanced ultrasound (CEUS) examination in the First Affiliated Hospital of Nanchang University from July 2022 to July 2023. Based on the tumor pathology and the results of enhanced CT, tumor patients were divided into malignant and benign groups. All subjects were examined using gray-scale ultrasound, conventional contrast-enhanced ultrasound (C-CEUS), and H-CEUS, and their dynamic images were recorded. Two radiologists independently analyzed and recorded the results of ultrasound, C-CEUS, and H-CEUS images and statistically analyzed the features of C-CEUS and H-CEUS images. The independent sample t-test was used to compare the difference in age and maximum diameter of nodules between the benign and malignant groups. The χ2 test was used to compare the sex, mode of operation, gray-scale ultrasound characteristics, and enhancement characteristics of the two CEUS modes (enhancement mode, regression mode, enhancement degree, enhancement uniformity, enhancement or not, enhancement direction, post-enhancement boundary and range, and pseudocapsule) between the benign and malignant groups. The difference in vascular morphology of malignant nodules of varying sizes under two angiographic modes.

RESULTS

There were significant differences in gender (χ2 = 10.408, P = 0.001), mode of operation (χ2 = 47.089, P < 0.001), nodule composition (χ2 = 7.481, P = 0.003), nodule echo (χ2 = 20.926, P < 0.001), necrosis (χ2 = 31.343, P < 0.001) and nodule blood flow (χ2 = 9.006, P = 0.029) between the benign and malignant groups. There were significant differences in the regression model (χ2 = 6.782, P = 0.034) and enhancement direction (χ2 = 13.771, P = 0.001) between the two radiographic techniques in the malignant group. There was a significant difference in the enhancement uniformity between the two CEUS techniques in the benign group (χ2 = 8.264, P = 0.004). There was a significant difference between the two CEUS techniques in displaying the vascular morphology in the malignant group with the maximum diameter of nodules ≤ 4.0 cm (χ2 = 11.421, P < 0.022). However, there was no significant difference between the two techniques in the malignant group with the maximum diameter of nodules > 4.0 cm.

CONCLUSION

Increasing the frame rate of ultrasound images is helpful to accurately display the enhanced features and vascular morphology of renal tumors, especially for malignant tumors with a maximum diameter of ≤ 4.0 cm. Thus, H-CEUS can make up for the limitation of CEUS with regard to the display of vascular morphology.

Aided diagnosis of thyroid nodules based on an all-optical diffraction neural network

Background

Thyroid cancer is the most common malignancy in the endocrine system, with its early manifestation being the presence of thyroid nodules. With the advantages of convenience, noninvasiveness, and a lack of radiation, ultrasound is currently the first-line screening tool for the clinical diagnosis of thyroid nodules. The use of artificial intelligence to assist diagnosis is an emerging technology. This paper proposes the use optical neural networks for potential application in the auxiliary diagnosis of thyroid nodules.

Methods

Ultrasound images obtained from January 2013 to December 2018 at the Institute and Hospital of Oncology, Tianjin Medical University, were included in a dataset. Patients who consecutively underwent thyroid ultrasound diagnosis and follow-up procedures were included. We developed an all-optical diffraction neural network to assist in the diagnosis of thyroid nodules. The network is composed of 5 diffraction layers and 1 detection plane. The input image is placed 10 mm away from the first diffraction layer. The input of the diffractive neural network is light at a wavelength of 632.8 nm, and the output of this network is determined by the amplitude and light intensity obtained from the detection region.

Results

The all-optical neural network was used to assist in the diagnosis of thyroid nodules. In the classification task of benign and malignant thyroid nodules, the accuracy of classification on the test set was 97.79%, with an area under the curve value of 99.8%. In the task of detecting thyroid nodules, we first trained the model to determine whether any nodules were present and achieved an accuracy of 84.92% on the test set.

Conclusions

Our study demonstrates the potential of all-optical neural networks in the field of medical image processing. The performance of the models based on optical neural networks is comparable to other widely used network models in the field of image classification.

New Technologies in the Assessment of Carotid Stenosis: Beyond the Color-Doppler Ultrasound-High Frame Rate Vector-Flow and 3D Arterial Analysis Ultrasound

Atherosclerotic plaque in the carotid artery is the main cause of ischemic stroke, with a high incidence rate among people over 65 years. A timely and precise diagnosis can help to prevent the ischemic event and decide patient management, such as follow up, medical, or surgical treatment. Presently, diagnostic imaging techniques available include color-Doppler ultrasound, as a first evaluation technique, computed tomography angiography, which, however, uses ionizing radiation, magnetic resonance angiography, still not in widespread use, and cerebral angiography, which is an invasively procedure reserved for therapeutically purposes. Contrast-enhanced ultrasound is carving out an important and emerging role which can significantly improve the diagnostic accuracy of an ultrasound. Modern ultrasound technologies, still not universally utilized, are opening new horizons in the arterial pathologies research field. In this paper, the technical development of various carotid artery stenosis diagnostic imaging modalities and their impact on clinical efficacy is thoroughly reviewed.

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.