Time-intensity Curve Parameters Research Articles

Qualitative and quantitative analysis of solid renal tumors by high-frame-rate contrast-enhanced ultrasound

ObjectiveTo analyze the characteristics of high-frame-rate contrast-enhanced ultrasound (H-CEUS) in solid renal tumors using qualitative and quantitative methods.MethodsSeventy-five patients who underwent preoperative conventional ultrasound (US), conventional contrast-enhanced ultrasound (C-CEUS), and H-CEUS examination of renal tumors were retrospectively analyzed, with a total of 89 renal masses. The masses were divided into the benign (30 masses) and malignant groups (59 masses) based on the results of enhanced computer tomography and pathology. The location, diameter, shape, border, calcification, and color doppler blood flow imaging (CDFI) of the lesions were observed by US, and the characteristics of the C-CEUS and H-CEUS images were qualitatively and quantitatively analyzed. The χ² test or Fisher’s exact probability method was used to compare the US image characteristics between the benign and malignant groups, and the image characteristics of C-CEUS and H-CEUS between the benign and malignant groups. Moreover, the nonparametric Mann-Whitney test was used to compare the differences in C-CEUS and H-CEUS time-intensity curve (TIC) parameters.ResultsSignificant differences in gender, surgical approach, echogenicity, and CDFI were observed between the malignant and benign groups (p = 0.003, < 0.001, < 0.001, = 0003). Qualitative analysis also revealed significant differences in the mode of wash-out and fill-in direction between C-CEUS and H-CEUS in the malignant group (p = 0.041, 0.002). In addition, the homogeneity of enhancement showed significant differences between the two contrast models in the benign group (p = 0.009). Quantitative analysis indicated that the TIC parameters peak intensity (PI), deceleration time (DT) /2, area under the curve (AUC), and mean transition time (MTT) were significantly lower in the H-CEUS model compared to the C-CEUS model in both the benign and malignant groups. (all p < 0.001). In contrast, ascending slope of rise curve (AS) was significantly higher in the H-CEUS model compared to the C-CEUS model in the malignant group (p = 0.048).ConclusionsIn renal tumors, H-CEUS shows clearer internal enhancement of the mass and the changes in the wash-out period. The quantitative TIC parameters PI, DT/2, AUC, and MTT were lower in H-CEUS compared to C-CEUS. Both the quantitative and qualitative analyses indicated that H-CEUS better displays the characteristics of solid renal masses compared with C-CEUS.

Qualitative and quantitative assessment of non-clear cell renal cell carcinoma using contrast-enhanced ultrasound

BackgroundNon-clear cell renal cell carcinoma (nccRCC) represents a rare form of renal cell carcinoma (RCC) in the clinic. It is now understood that contrast-enhanced ultrasound (CEUS) exhibits diverse manifestations and can be prone to misdiagnosis. Therefore, summarizing the distinctive features of contrast-enhanced ultrasonography is essential for differentiation from ccRCC.ObjectiveThis study aims to evaluate the diagnostic efficacy of qualitative and quantitative CEUS in diagnosing nccRCC to enhance our understanding of this condition.MethodsWe conducted a retrospective analysis of 21 patients with confirmed nccRCC following surgery and assessed the characteristic conventional ultrasound and CEUS imaging features. The paired Wilcoxon signed-rank sum test was employed to compare differences in CEUS time-intensity curve (TIC) parameters between the lesions and the normal renal cortex.ResultsRoutine ultrasound revealed the following primary characteristics in the 21 nccRCC cases: hypoechoic appearance (10/21, 47.6%), absence of liquefaction (18/21, 66.7%), regular shape (19/21, 90.5%), clear boundaries (21/21, 100%), and absence of calcification (17/21, 81%). Color Doppler flow imaging (CDFI) indicated a low blood flow signal (only 1 case of grade III). Qualitative CEUS analysis demonstrated that nccRCC predominantly exhibited slow progression (76.1%), fast washout (57%), uniformity (61.9%), low enhancement (71.5%), and ring enhancement (61.9%). Quantitative CEUS analysis revealed that parameters such as PE, WiAUC, mTTI, WiR, WiPI, WoAUC, WiWoAUC, and WOR in the lesions were significantly lower than those in the normal renal cortex (Z=-3.980, -3.563, -2.427, -3.389, -3.980, -3.493, -3.528, -2.763, P < 0.001, < 0.001, = 0.015, = 0.001, < 0.001, < 0.001, < 0.001, = 0.006). However, there were no significant differences in RT, TTP, FT, or QOF (all P > 0.05).ConclusionnccRCC exhibits distinctive CEUS characteristics, including slow progression, fast washout, low homogeneity enhancement, and ring enhancement, which can aid in distinguishing nccRCC from ccRCC.

Contrast-enhanced ultrasound (CEUS): applications from the kidneys to the bladder.

Contrast-enhanced ultrasound (CEUS) is an advanced ultrasound (US) technique utilizing ultrasound contrast agents (UCAs) to provide detailed visualization of anatomic and vascular architecture, including the depiction of microcirculation. CEUS has been well-established in echocardiography and imaging of focal hepatic lesions and recent studies have also shown the utility of CEUS in non-hepatic applications like the urinary system. The updated guidelines by the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) from 2018 describe the use of CEUS for non-hepatic applications. CEUS' excellent safety profile and spatial resolution make it a superior modality to conventional US and is often comparable and even superior to CECT in some instances. In comparison to other cross-sectional imaging modalities such as CECT or MRI, CEUS offers a safe (by virtue of non-nephrotoxic US contrast agents), accurate, cost-efficient, readily available, and a quick means of evaluation of multiple pathologies of the urinary system. CEUS also has the potential to reduce the overall economic burden on patients requiring long-term follow-up due to its low cost as compared to CT or MRI techniques. This comprehensive review focuses on the applications of CEUS in evaluating the urinary system from the kidneys to the urinary bladder. CEUS can be utilized in the kidney to evaluate complex cystic lesions, indeterminate lesions, pseudotumors (vs solid renal tumors), renal infections, and renal ischemic disorders. Additionally, CEUS has also been utilized in evaluating renal transplants. In the urinary bladder, CEUS is extremely useful in differentiating a bladder hematoma and bladder cancer when conventional US techniques show equivocal results. Quantitative parameters of time-intensity curves (TICs) of CEUS examinations have also been studied to stage and grade bladder cancers. Although promising, further research is needed to definitively stage bladder cancers and classify them as muscle-invasive or non-muscle invasive using quantitative CEUS to guide appropriate intervention. CEUS has been very effective in the classification of cystic renal lesions, however, further research is needed in differentiating benign from malignant renal masses.

Assessing IgG4-related autoimmune pancreatitis with contrast-enhanced ultrasonography based on time-intensity curve: a single-centre prospective study.

The aim of this study was to investigate the changes in various parameters of contrast-enhanced ultrasound (CEUS) before and after treatment in patients with IgG4-related autoimmune pancreatitis (IgG4-AIP), and to identify potential indicators that can assist in evaluating disease activity. In this prospective study, we enrolled patients diagnosed with IgG4-AIP from June 2021 to November 2022. Demographic characteristics, clinical features, laboratory tests were recorded. Baseline and follow-up, conventional ultrasound and CEUS were conducted. Additionally, a region of interest (ROI) within lesions, pancreatic head, pancreatic body, and pancreatic tail was taken to draw time-intensity curves (TIC) and parameters of TIC were recorded and analysed. Seventy-three active IgG4-AIP patients were enrolled. Follow-up, a notable decrease in the size of the pancreatic lesion was observed with a reduction in the maximum diameter from 4.3 ± 2.0 cm to 1.7 ± 1.6 cm (p=0.01). The results revealed a statistically significant increase in peak intensity (PI) in the head, body, and tail regions of the pancreas (p<0.001), along with a significant rise in the area under the curve (AUC) in the tail region of the pancreas (p=0.029) after treatment compared to baseline. In contrast, no statistically significant differences were observed in other parameters of TIC. A significant increase of PI was observed in 12 patients with diffuse IgG4-AIP following treatment. Following treatment, there was a significant increase in PI in the focal area among the 12 patients with focal lesions. CEUS based on TIC holds great potential for assessing response to treatment in patients with IgG4 AIP.

The correlation between time-intensity curve parameters of transrectal contrast-enhanced ultrasound and pathological prognostic factors in rectal adenocarcinoma.

To investigate the correlation between time-intensity curve (TIC) parameters obtained from transrectal contrast-enhancedultrasound (TR-CEUS) and important pathological prognostic factors in rectal adenocarcinoma. We retrospectively included 477 patients with pathologically confirmed rectal adenocarcinoma. TIC parameters werederived from preoperative dynamic TR-CEUS images. These parameters included peak intensity (PI), time to peak (TTP),mean transit time (MTT), slope (S), and area under the curve (AREA). Pathological prognostic factors included TN stage,tumor diameter, lymphovascular invasion (LVI), perineural invasion, and tumor differentiation. Spearman's correlation analysisand binary logistic regression were used to analyze the association between TIC parameters and pathological prognosticfactors. pT1-2 stages rectal carcinomas exhibited higher PI-max, PI-min, S-max, S-min, AREA-max, and AREA-minthan pT3-4 stages (all p<0.05). pN0 stage rectal adenocarcinomas displayed higher PI-max, S-max, AREA-max, PI-ratio, Sratio,and AREA-ratio than pN1-2 stage (all p<0.05). PI-ratio and S-ratio were higher in the LVI-negative and tumor diameter≥4cm group compared to the LVI-positive and tumor diameter <4cm group, respectively (p<0.05). Well-differentiated rectaladenocarcinomas displayed higher PI-max, AREA-max, PI-ratio, S-ratio, and AREA-ratio than the moderate-poor differentiatedgroup (all p<0.05). PI-max, S-max, AREA-max, PI-ratio, S-ratio, and AREA-ratio were negatively correlated with pNstage (all p<0.05). PI-ratio and S-ratio were independent predictive factors for the pN stage (OR=0.774, OR=1.048). S-ratioand AREA-ratio were independent predictive factors for tumor differentiation (OR=1.071, OR=0.911). TIC parametersderived from TR-CEUS exhibit correlations with specific pathological prognostic factors in rectal adenocarcinomas.This non-invasive method may hold promise for preoperatively assessing the prognosis of rectal adenocarcinoma patients.

A Preliminary Study on the Application of Contrast-Enhanced Ultrasonography in Children With Peripheral Neuroblastic Tumors

The purpose of this study was to retrospectively analyze the characteristics of contrast-enhanced ultrasound (CEUS) images and quantitative parameters of time-intensity curves (TICs) in children's peripheral neuroblastic tumors (pNTs). By comparing the imaging features and quantitative parameters of the TICs of neuroblastoma (NB) and ganglioneuroblastoma (GNB) patients, we attempted to identify the distinguishing points between NB and GNB. A total of 35 patients confirmed to have pNTs by pathologic examination were included in this study. Each child underwent CEUS with complete imaging data (including still images and at least 3 min of video files). Twenty-four patients were confirmed to have NB, and 11 were considered to have GNB according to differentiation. The CEUS image features and quantitative parameters of the TICs of all lesions were analyzed to determine whether there were CEUS-related differences between the two types of pNT. There was a significant difference in the enhancement patterns of the CEUS features (χ2 = 5.303, p < 0.05), with more “peripheral-central” enhancement in the NB group and more “central-peripheral” enhancement in the GNB group. In the TIC, the rise time and time to peak were significantly different (p < 0.05). The receiver operating characteristic curve showed that the probability of ganglion cell NB increased significantly after RT > 15.29, with a sensitivity of 0.636 and a specificity of 0.958. When the peak time was greater than 16.155, the probability of NB increased significantly, with a sensitivity of 0.636 and a specificity of 0.958. The CEUS features of NB and GNB patients are very similar, and it is difficult to distinguish them. Rise time and time to peak may be useful in identifying GNB and NB, but the sample size of this study was small, and the investigation was only preliminary; a larger sample size is needed to support these conclusions.

Clinical value of contrast-enhanced ultrasound quantitative analysis for differentiating thyroid lesions in Hashimoto's thyroiditis patients.

The role of quantitative contrast-enhanced ultrasound (CEUS) in the evaluation of thyroid nodules with Hashimoto's thyroiditis (HT) has received little attention. This was a retrospective cohort study. We consecutively enrolled 242 patients (49 males, 193 females, average age 52 years) with a combined total of 248 thyroid nodules coexisting with HT who underwent biopsy/resection-proven pathology from December 2016 to June 2021. All patients underwent preoperative ultrasound (US) and CEUS examinations performed by 2 radiologists independently. Quantitative analysis of CEUS using time-intensity curves (TIC) was measured by an expert radiologist from the thyroid intra-nodule and the surrounding parenchyma and their ratios. Receiver operating characteristic (ROC) analysis was performed to evaluate their diagnostic performance. The patients were divided into the nodular HT (NHT) group (n=42), the papillary thyroid carcinoma (PTC) group (n=154), and the primary thyroid lymphoma (PTL) group (n=52) according to their pathological results. TIC parameters revealed that PTC and PTL showed faster time to peak (TTP) (P=0.044, P=0.049), lower peak intensity (PI) (both P<0.001), and smaller areas under the curve (both P<0.001) than those of NHT. The intra nodule of PTL showed an obviously slower perfusion (ratio =0.90, P<0.001) and lower PI (ratio =0.84, P<0.001) compared with the thyroid parenchyma. TIC improved performance in distinguishing PTL from NHT [area under the curve (AUC): 0.947, 95% confidence interval (CI): 0.903-0.991], but inferior performance in differentiating PTC and NHT (AUC: 0.838, 95% CI: 0.759-0.917). CEUS quantitative analysis could be valuable in differentiating thyroid malignancies in patients with HT.

Ultrasound biomicroscopy in the quantification of brain perfusion parameters of a rat stroke model: Analysis of contrast agent bolus kinetic dynamics

BackgroundIschemic stroke represents a significant global health concern, necessitating thorough investigations and the utilization of stroke animal models to explore novel treatment modalities and diagnostic imaging techniques. New methodUltrasound biomicroscopy (BMU), operating at a center frequency of 21 MHz, along with ultrasound contrast agents (UCAs), was used to quantify microcirculation cerebral blood flow in a rat model of ischemic stroke. The microcirculation parameters were derived from time intensity curve (TIC) plots obtained based on UCA-bolus kinetics. ResultsSemiquantitative perfusion-related parameters were assessed. The TIC curves showed differences in amplitude when compared intra-animal between the left and right sides, and three situations were observed: normal perfusion, hypoperfusion, and nonperfusion. ROC analysis of delays between the left and right time intensity peak (TIP) for regions of interest (ROIs) in the control and stroke-hypoperfusion groups revealed an optimal cutpoint of 0.39 s to indicate when hypoperfusion is occurring in rats, with a sensitivity of 93.33 % and a specificity of 80 %. Comparison with existing method(s)Ultrasound perfusion imaging through the temporal bone window has been clinically applied to stroke patients using a UCA bolus for TIC analysis. TIC parameters were correlated with MRI- and CT-based measurements. ConclusionsThis investigation quantified cerebral blood flow in a rat model of ischemic stroke by measuring microcirculation parameters. The study demonstrated the efficacy of this approach as a valuable tool for conducting preclinical studies.

Dynamic assessment of brain perfusion in a middle cerebral artery occlusion rat model by contrast-enhanced ultrasound imaging: a pilot study.

The middle cerebral artery occlusion model (MCAo) is a commonly used animal model for cerebral ischemia studies but lacks accessible imaging techniques for the assessment of hemodynamic changes of the model. The study aims to explore the value of contrast-enhanced ultrasound (CEUS) in evaluating brain perfusion in the early stages after MCAo surgery. In total, 18 adult male Sprague-Dawley rats were subjected to right MCAo using an intraluminal filament model, and CEUS was performed at the three following timepoints: before (T0), immediately after (T1), and 6 h after permanent MCAo (T2). Twelve rats successfully completed the study, and their brains were removed and stained using 2, 3, 5-triphenyltetrazolium chloride (TTC). CEUS video images were visualized offline, and the time-intensity curves (TICs) were analyzed. Different cerebrovascular patterns and manifestations of the contrast enhancement in rat ischemic hemispheres were observed. Semi-quantitative parameters of TICs in ischemic areas (ROIi) and the surrounding normal- or hypo-perfused areas (ROIn) were calculated and compared between T0, T1, and T2, and also between ROIi and ROIn. A significant correlation was found between the lesion volume (%) determined by TTC and CEUS parameters (r = -0.691, P = 0.013 for peak intensity; r = -0.742, P = 0.006 for area under the curve) at T2. After the same occlusion, there were differences in contrast perfusion in each group. This study suggests that CEUS could be an effective imaging tool for studying cerebral ischemia and perfusion in small animals as long as the transcranial acoustic window allows it.

Domain knowledge-guided adversarial adaptive fusion of hybrid breast ultrasound data

Contrast-enhanced ultrasound (CEUS), which provides more detailed microvascular information about the tumor, is always taken by radiologists in clinic diagnosis along with B-mode ultrasound (B-mode US). However, automatically analyzing breast CEUS is challenging due to the difference between the CEUS video and the natural video, e.g., sports or action videos, where the CEUS video has no positional displacements. Additionally, most existing methods rarely use the Time Intensity Curve (TIC) information of CEUS and non-imaging clinical (NIC) data. To address these issues, we propose a novel breast cancer diagnosis framework that learns the complementarity and correlation across hybrid modal data, including CEUS, B-mode US, and NIC data, by an adversarial adaptive fusion method. Furthermore, to fully exploit the CEUS information, the proposed method, inspired by the clinical processing of radiologists, first extracts the TIC parameters of CEUS. Then, we select a clip from CEUS using a frame screening strategy and finally get spatio-temporal features from these clips through a critical frame attention network. To our knowledge, this is the first AI system to use TIC parameters, NIC data, and ultrasound imaging in diagnoses. We have validated our method on a dataset collected from 554 patients. The experimental results demonstrate the excellent performance of the proposed method. The result shows that our method can achieve an accuracy of 87.73%, which is higher than that of uni-modal approaches by nearly 5%.

An Automated Method for Classifying Liver Lesions in Contrast-Enhanced Ultrasound Imaging Based on Deep Learning Algorithms.

Contrast-enhanced ultrasound (CEUS) is an important imaging modality in the diagnosis of liver tumors. By using contrast agent, a more detailed image is obtained. Time-intensity curves (TIC) can be extracted using a specialized software, and then the signal can be analyzed for further investigations. The purpose of the study was to build an automated method for extracting TICs and classifying liver lesions in CEUS liver investigations. The cohort contained 50 anonymized video investigations from 49 patients. Besides the CEUS investigations, clinical data from the patients were provided. A method comprising three modules was proposed. The first module, a lesion segmentation deep learning (DL) model, handled the prediction of masks frame-by-frame (region of interest). The second module performed dilation on the mask, and after applying colormap to the image, it extracted the TIC and the parameters from the TIC (area under the curve, time to peak, mean transit time, and maximum intensity). The third module, a feed-forward neural network, predicted the final diagnosis. It was trained on the TIC parameters extracted by the second model, together with other data: gender, age, hepatitis history, and cirrhosis history. For the feed-forward classifier, five classes were chosen: hepatocarcinoma, metastasis, other malignant lesions, hemangioma, and other benign lesions. Being a multiclass classifier, appropriate performance metrics were observed: categorical accuracy, F1 micro, F1 macro, and Matthews correlation coefficient. The results showed that due to class imbalance, in some cases, the classifier was not able to predict with high accuracy a specific lesion from the minority classes. However, on the majority classes, the classifier can predict the lesion type with high accuracy. The main goal of the study was to develop an automated method of classifying liver lesions in CEUS video investigations. Being modular, the system can be a useful tool for gastroenterologists or medical students: either as a second opinion system or a tool to automatically extract TICs.

Classifying Kidney Disease in a Vervet Model Using Spatially Encoded Contrast-Enhanced Ultrasound Perfusion Parameters.

Early stages of diabetic kidney disease (DKD) are difficult to diagnose in patients with type 2 diabetes. This work was aimed at identifying contrast-enhanced ultrasound (CEUS) perfusion parameters, a microcirculatory biomarker indicative of early DKD progression. CEUS kidney flash-replenishment data were acquired in control, insulin resistant and diabetic vervet monkeys (N=16). By use of a mono-exponential model, time-intensity curve parameters related to blood volume (A), velocity (β) and flow rate (perfusion index [PI]) were extracted from 10 concentric kidney layers to study spatial perfusion patterns that could serve as strong indicators of disease. Mean squared error (MSE) was used to assess model performance. Features calculated from the perfusion parameters were inputs for the linear regression models to determine which features could distinguish between cohorts. The mono-exponential model performed well, with average MSEs (±standard deviation) of 0.0254 (±0.0210), 0.0321 (±0.0242) and 0.0287 (±0.0130) for the control, insulin resistant and diabetic cohorts, respectively. Perfusion index features, with blood pressure, were the best classifiers between cohorts (p < 0.05). CEUS has the potential to detect early microvascular changes, providing insight into disease-related structural changes in the kidney. The sensitivity of this technique should be explored further by assessing various stages of DKD.

Correlation between serum cystatin C level and renal microvascular perfusion assessed by contrast-enhanced ultrasound in patients with diabetic kidney disease

Objectives To investigate the relationship between serum cystatin C (CysC) levels and renal microvascular perfusion in patients with diabetic kidney disease (DKD). Methods A total of 57 patients with high CysC levels and 45 patients with normal CysC levels were enrolled. Data on clinical characteristics and laboratory examination results were also collected. Contrast-enhanced ultrasound (CEUS) of the kidneys was successively performed. The time-intensity curve (TIC) and related quantitative parameters of the kidneys were obtained by CEUS and the correlations between CysC and CEUS parameters were analyzed. Results Compared to the normal CysC group, the high CysC group had significantly lower wash-in area under the curve (WiAUC), wash-out area under the curve (WoAUC), and wash-in and wash-out area under the curve (WiWoAUC). In the normal CysC group, patients with Stage III chronic kidney disease (CKD) had higher AUCs than those with Stage I–II CKD (p < 0.05). In the high CysC group, patients with Stage IV–V CKD had lower wash-in AUC compared to patients with Stage I–II CKD (p = 0.023). The renal cortex microvascular perfusion parameters AUCs were positively correlated with the estimated glomerular filtration rate (GFR) (r = 0.280, 0.222, and 0.243), and CysC was inversely correlated with AUCs (r= −0.299, −0.251, and −0.273). Conclusions CEUS parameters reflected changes in renal microvascular perfusion in patients with DKD, while AUCs might be useful indicators of declining GFR in DKD patients with increased CysC.

Classification of contrast-enhanced ultrasonograms in rectal cancer according to tumor inhomogeneity using machine learning-based texture analysis

BackgroundInhomogeneity within tumors can reflect tumor angiogenesis. Existing research into the quantization of angiogenesis mainly focuses on time-intensity curve parameters but has produced inconsistent results. In clinical work, it is difficult to achieve standardization and consistency for manual judgement of the inhomogeneity of contrast-enhanced images, while the artificial intelligence technology may be helpful. The aim of this study was to assess whether computers can assist in the artificial classification of tumor inhomogeneity in contrast-enhanced ultrasound (CEUS) images of rectal cancer.MethodsA total of 500 contrast-enhanced ultrasonograms were retrospectively collected, which was verified of rectal cancer pathologically from 2016 to 2018 as training set. All images are from 18–80 years old patients with rectal cancer in our hospital. These tumors are usually located in the middle and lower segment of the rectum, which can be completely observed on ultrasound. The images were divided into 3 categories according to the inhomogeneous distribution of contrast agents inside the tumors. Computing methods were used to simulate manual classification. Computer processing steps included segmentation, gray level quantization, dimension reduction, and classification. The results of 6 different gray level quantization, 2 dimensionality reduction methods, and 3 classifiers were compared, from which the optimal parameters were selected in each step. The performance of computer classification was evaluated using manual classification results as the reference. Ninety-seven ultrasonograms of contrast-enhanced rectal tumors were collected as validation set from 2018.1 to 2018.6.ResultsThe optimal gray level was set at 32. Principal component analysis (PCA) was the first choice for dimensionality reduction. The best classifier was support vector machines (SVM). The accuracy of computer classification was 87.80% (439/500). The accuracy of computer classification in the validation cohort was 60.82%. The area under the curve (AUC) of class 1, 2, and 3 were 0.76, 0.41, and 0.48, respectively.ConclusionsResults showed that the computer methods are competent for classifying inhomogeneity of contrast-enhanced rectal cancers inside ultrasonograms.

Use of Contrast-Enhanced Ultrasound of the Testes after Non-Surgical Sterilization of Male Dogs with CaCl2 in Alcohol.

Simple SummaryThe uncontrolled stray dog population presents a serious threat to public health due to the increased risk of transmitting zoonotic diseases and inflicting human injury. There is a growing interest in non-surgical chemical sterilization via intratesticular injection of chemical neutering agents such as calcium chloride, which causes sterility due to azoospermia. In this study, we monitored immediate vascular alterations in dogs from chemical sterilization, using contrast-enhanced ultrasound (CEUS) before and after intratesticular inoculation with calcium chloride. The CEUS is an imaging technique used to obtain a quali-quantitative assessment of tissue perfusion by intravenously injecting gas-filled microbubble contrast agent. The CEUS evaluation was performed in canine testes before and after intratesticular inoculation with calcium chloride. Our results showed that the hardening agent caused a drastic reduction of the intratesticular blood flow, which was reflected by sonographic findings. CEUS can help clinicians define immediate testicular vascular alterations achieved by chemical castration. Nevertheless, more studies are required to apply this methodology to more subjects in a broader weight range among stray dogs.Sterilization by intratesticular injection of chemical agents is a non-surgical alternative to neutering male companion animals. We used contrast-enhanced ultrasound (CEUS) to monitor vascular alterations to testes immediately after the intratesticular injection of CaCL2 in alcohol. We evaluated the CEUS features of normal and damaged testes in 20 dogs after the intratesticular injection of CaCl2. The CEUS evaluation was performed at the site of the chemical agent inoculation. In treated testes, qualitative CEUS showed a lower intensity enhancement of the parenchyma than pre-treatment normal testes with a predominantly anechoic pattern and only a few hyperechoic vascular focal spots. Quantitative CEUS showed significantly lower values of time-intensity curve (TIC) parameters, including signal intensity (Peak: 4.72 ± 2.1), regional blood volume (RBV: 134.3 ± 63.7), and regional blood flow (RBF: 4.36 ± 2.18) than normal testes (p < 0.001). Sonographic findings from CEUS showed hypovascularization of the canine testicular parenchyma caused by the hardening agent. This diagnostic technique helps clinicians define testicular vascular alterations achieved by chemical castration more efficiently. Nevertheless, more studies are required to apply this methodology to more subjects with a broader weight range and stray dogs.

Contrast-enhanced ultrasound imaging for intestinal lymphoma.

BACKGROUNDIntestinal lymphoma is a rare tumor. Contrast-enhanced ultrasound (CEUS) findings of intestinal lymphoma have not been reported previously, and the relationship between CEUS and clinicopathological features and prognostic factors is still unknown.AIMTo describe the B-mode US and CEUS features of intestinal lymphoma and investigate the correlation of CEUS and histopathological features.METHODSThis was a single-center retrospective study. Eighteen patients with histologically confirmed intestinal lymphoma underwent B-mode US and CEUS examinations between October 2016 and November 2019. We summarized the features of B-mode US and CUES imaging of intestinal lymphoma and compared the frequency of tumor necrosis in intestinal lymphomas with reference to different pathological subtypes (aggressive or indolent) and clinical stage (early or advanced). The time–intensity curve parameters of CEUS were also compared between patients with normal and elevated serum lactate dehydrogenase.RESULTSIn B-mode imaging, four patterns were observed in intestinal lymphoma: Mass type (12/18, 66.7%), infiltration type (1/18, 5.6%), mesentery type (4/18, 22.2%) and mixed type (1/18, 5.6%). All cases were hypoechoic and no cystic areas were detected. On CEUS, most cases (17/18, 94.4%) showed arterial hyperechoic enhancement. All cases showed arterial enhancement followed by venous wash out. A relatively high rate of tumor necrosis (11/18, 61.1%) was observed in this study. Tumor necrosis on CEUS was more frequent in aggressive subtypes (10/13, 76.9%) than in indolent subtypes (1/5, 20.0%) (P = 0.047). There were no correlations between tumor necrosis and lesion size and Ann Arbor stage. There was no significant difference in time–intensity curve parameters between normal and elevated lactate dehydrogenase groups.CONCLUSIONB-mode US and CEUS findings of intestinal lymphoma are characteristic. We observed a high rate of tumor necrosis, which appeared more frequently in aggressive pathological subtypes of intestinal lymphoma.

Use of contrast-enhanced ultrasound during preoperative evaluation of endometrial carcinoma

ObjectiveTo explore the clinical role of contrast-enhanced ultrasound (CEUS) in a preoperative evaluation of early endometrial carcinoma. MethodsThis study included 14 patients who underwent preoperative CEUS and contrast-enhanced magnetic resonance imaging (CEMRI) and were ultimately diagnosed with stage I endometrial carcinoma from December 2019 to December 2020. The parameters of the time-intensity curve (TIC) were compared with the endometrial carcinoma group, the invaded myometrium group, and the normal myometrium group. ResultsTIC parameters between the endometrial carcinoma group and the invaded myometrium group were similar. Compared with the normal myometrium group, the time to peak (TTP) was significantly shorter and the ascending slope (AS) was significantly higher in the endometrial carcinoma group. The TTP of the invaded myometrium group was shorter than that of the normal myometrium group and the peak intensity (PI) was higher than that of the normal myometrium group. We then compared the TIC parameters between the endometrial carcinoma group and the invaded myometrium group after adjusting for the normal myometrium group, and the results still did not show any difference. Of the 14 cases of endometrial carcinoma, 9 cases were diagnosed by CEMRI and were consistent with the pathology results, 1 case was underestimated, and 4 cases were overestimated; while 11 cases diagnosed were diagnosed by CEUS and were consistent with the pathology results, 1 case was underestimated, and 2 cases were overestimated. ConclusionsThe contrast pulse sequencing technique used in the CEUS examinations performed well in evaluating the extent of the endometrial carcinoma. Future studies with larger sample sizes are needed to determine the applicability and value of this new procedure during preoperative assessments of early endometrial carcinoma.

Quantitative analysis of renal blood flow during thoracic endovascular aortic repair in type B aortic dissection using syngo iFlow.

Currently, the thoracic endovascular aortic repair is the recommended clinical treatment for type B aortic dissections. Unfortunately, malperfusion or ischemia of the kidneys is a major complication of type B aortic dissections. Despite this, few studies have focused on the effects of thoracic endovascular aortic repair on blood flow in renal arteries and parenchyma. This current investigation used novel real-time imaging software to quantitatively analyze the hemodynamic changes in renal artery blood flow and perfusion before and after stent graft placement. A total of 51 patients with type B aortic dissection undergoing thoracic endovascular aortic repair between April 2017 and September 2019 were retrospectively recruited. The pre-and post-procedural digital subtraction angiography images were converted into color-coded maps using syngo iFlow for quantitative comparison. Time-intensity curves and related parameters, including the average peak ratio (avg.Pr), average delayed time to peak (avg.dTTP), and average area under the curve ratio (avg.AUCr) of the renal arteries and renal cortex were obtained and analyzed. Wilcoxon signed-rank test was used to compare iFlow parameters before and after endovascular repair. Spearman correlation analyses were performed to study iFlow parameters and renal function parameters and the estimated glomerular filtration rate (eGFR) and blood urea nitrogen (BUN). A total of 102 images including 51 pre-operative and 51 post-operative image datasets were successfully post-processed. Following endovascular repair, syngo iFlow showed a significant 33.0% increase in avg.Pr (P<0.001) and a significant 35.1% increase in avg.AUCr (P<0.001) in the renal artery. Additionally, there was a significant 12.2% decrease in the avg.dTTP (P=0.001), a significant 24.5% increase in avg.Pr (P=0.004), and a significant 38.3% increase in avg.AUCr (P=0.009) in the renal cortex. Spearman correlation analysis showed that after endovascular repair there was a significant correlation between the avg.Pr of the renal artery and eGFR (r=0.30; P=0.0349), the avg.Pr of the renal cortex and eGFR (r=0.30; P=0.0300), and the avg. AUCr of the renal cortex and BUN (r=0.31; P=0.0289). syngo iFlow provided a novel quantitative method for evaluating renal hemodynamic changes in patients with type B aortic dissection undergoing endovascular treatment. Time-intensity curve parameters may facilitate the intraprocedural evaluation of renal blood flow and perfusion to complement the color-coded map.

Assessment of Microcirculation in the Type 2 Diabetic and Impaired Glucose Tolerance Feet of Elderly Men by CEUS.

ObjectiveTo evaluate the foot microcirculation in type 2 diabetes mellitus (T2DM) and impaired glucose tolerance patients (IGT) with contrast-enhanced ultrasound (CEUS).MethodsThe study included 37 patients with T2DM but without diabetic foot (DM group), 15 patients with impaired glucose tolerance (IGT group) and 10 elderly males with normal fasting blood glucose (FBS) and negative glucose tolerance tests (control group). Color Doppler flow imaging (CDFI) and CEUS were performed on the right foot great toes for detecting the blood perfusion performance. CEUS images were recorded and parameters of CDFI and flow time-intensity curves (TICs) were analyzed by the Student’s t-test.ResultsThere was no significant difference in CDFI parameters pulse index and peak systolic blood flow velocity (PSV) among the three groups (P >0.05). Compared with control group, CEUS images of IGT and DM groups showed lower microvascular density and were pale. Peak intensity (PI) and area under time-intensity curve (AUC) in control, IGT and DM groups were decreased gradually (PI 46.36±10.96 vs 35.26±11.65 vs 28.15±7.94, P = 0.001, AUC 5.12±1.02 vs 3.25±1.60 vs 2.81±1.20, P = 0.001). The arrival times (AT) and time to peak (TTP) tended to be increased with the extension of DM course, but the difference was not statistically significant (AT, P = 0.260, TTP, P = 0.481).ConclusionCEUS, as a noninvasive and valuable technique, could detect the alterations in foot microcirculation of DM and IGT patients.

Comparative Study of Qualitative and Quantitative Analyses of Contrast-Enhanced Ultrasound and the Diagnostic Value of B-Mode and Color Doppler for Common Benign Tumors in the Parotid Gland.

PurposeTo preliminarily identify three common benign parotid gland tumors: pleomorphic adenomas (PA), Warthin tumors (WT), and basal cell adenomas (BCA) by qualitative and quantitative analyses using contrast-enhanced ultrasound (CEUS).MethodsPreoperative images of parotid gland masses were analyzed, including 129 cases of ultrasonography (US) and color Doppler sonography (CDS) and 110 cases of qualitative and quantitative CEUS. The diagnosis was confirmed by postsurgical pathology outcomes.ResultsPA presented low and heterogeneous enhancement and echo-free area, whereas most WT and BCA presented with high and relatively homogeneous enhancement. Compared with WT and BCA groups, a “slow in” pattern was more common in the PA group and a “slow out” pattern was more frequently noted in the WT group than in the PA and BCA groups. The unique features of qualitative CEUS in the PA group enable distinguishing PA from the 2 other groups. The further distinction among the groups was made based on quantitative parameters of time-intensity curves (TICs), which revealed that the mean peak intensity (PI), mean transit time (MTT), the area under the curve (AUC), and time from peak to one half (HT) exhibited significant differences. ROC analysis was next applied to determine the optimal cutoff points to predict the diagnostic tendency among the groups. When the rising slope (RS) was >2.145, the possibility of BCA was greater than WT.ConclusionsCEUS ultrasound is of significant value in the differential diagnosis of the 3 common benign parotid gland masses.