Contrast-enhanced ultrasound imaging of the vasa vasorum of carotid artery plaque

The vasa vasorum of carotid artery plaque is a novel marker of accurately evaluating the vulnerability of carotid artery plaque, which was associated with symptomatic cerebrovascular and cardiovascular disease. The presence of ultrasound contrast agents in carotid artery plaque represents the presence of the vasa vasorum in carotid artery plaque because the ultrasoundcontrast agents are strict intravascular tracers. Therefore, contrast-enhanced ultrasound(CEUS) is a novel and safe imaging modality for evaluating the vasa vasorum in carotid artery plaque. However, there are some issues that needs to be assessed to embody fully the clinical utility of the vasa vasorum in carotid artery plaque with CEUS.

Survival Analysis of Patients Undergoing Intraoperative Contrast-enhanced Ultrasound in the Surgical Treatment of Malignant Glioma

Objective:Complete resection of malignant gliomas is often challenging.Our previous study indicated that intraoperative contrast-enhanced ultrasound(ICEUS)could aid in the detection of residual tumor remnants and the total removal of brain lesions.This study aimed to investigate the survival rates of patients undergoing resection with or without the use of ICEUS and to assess the impact of ICEUS on the prognosis of patients with malignant glioma.Methods:A total of 64 patients diagnosed with malignant glioma(WHO grade HI and IV)who underwent surgery between 2012 and 2018 were included.Among them,29 patients received ICEUS.The effects of ICEUS on overall survival(OS)and progression-free survival(PFS)of patients were evaluated.A quantitative analysis was performed to compare ICEUS parameters between gliomas and the surrounding tissues.Results:The ICEUS group showed better survival rates both in OS and PFS than the control group.The univariate analysis revealed that age,pathology and ICEUS were significant prognostic factors for PFS,with only age being a significant prognostic factor for OS.In multivariate analysis,age and ICEUS were significant prognostic factors for both OS and PFS.The quantitative analysis showed that the intensity and transit time of microbubbles reaching the tumors were significantly different from those of microbubbles reaching the surrounding tissue.Conclusion:ICEUS facilitates the identification of residual tumors.Age and ICEUS are prognostic factors for malignant glioma surgery,and use of ICEUS offers a better prognosis for patients with malignant glioma.

Contrast-enhanced guided endoscopic ultrasound procedures

Contrast-enhanced endoscopic ultrasound(CH-EUS)can overcome the limi-tations of endoscopic ultrasound-guided acquisition by identifying microvessels inside inhomogeneous tumours and improving the characterization of these tumours.Despite the initial enthusiasm that oriented needle sampling under CH-EUS guidance could provide better diagnostic yield in pancreatic solid lesions,further studies did not confirm the supplementary values in cases of tissue acquisition guided by CH-EUS.This review details the knowledge based on the available data on contrast-guided procedures.The indications for CH-EUS tissue acquisition include isoechoic EUS lesions with poor visible delineation where CH-EUS can differentiate the lesion vascularisation from the surrounding parenchyma and also the mural nodules within biliopancreatic cystic lesions,which occur in select cases.Additionally,the roles of CH-EUS-guided therapy in patients whose pancreatic fluid collections or bile ducts that have an echogenic content have indications for drainage,and patients who have nonvisualized vessels that need to be highlighted via Doppler EUS are presented.Another indication is represented if there is a need for an immediate assessment of the post-radiofrequency ablation of pancreatic neuroendocrine tumours,in which case CH-EUS can be used to reveal the incomplete tumour destruction.

A Novel Approach to Breast Tumor Detection: Enhanced Speckle Reduction and Hybrid Classification in Ultrasound Imaging

Breast cancer detection heavily relies on medical imaging, particularly ultrasound, for early diagnosis and effectivetreatment. This research addresses the challenges associated with computer-aided diagnosis (CAD) of breastcancer fromultrasound images. The primary challenge is accurately distinguishing between malignant and benigntumors, complicated by factors such as speckle noise, variable image quality, and the need for precise segmentationand classification. The main objective of the research paper is to develop an advanced methodology for breastultrasound image classification, focusing on speckle noise reduction, precise segmentation, feature extraction, andmachine learning-based classification. A unique approach is introduced that combines Enhanced Speckle ReducedAnisotropic Diffusion (SRAD) filters for speckle noise reduction, U-NET-based segmentation, Genetic Algorithm(GA)-based feature selection, and Random Forest and Bagging Tree classifiers, resulting in a novel and efficientmodel. To test and validate the hybrid model, rigorous experimentations were performed and results state thatthe proposed hybrid model achieved accuracy rate of 99.9%, outperforming other existing techniques, and alsosignificantly reducing computational time. This enhanced accuracy, along with improved sensitivity and specificity,makes the proposed hybrid model a valuable addition to CAD systems in breast cancer diagnosis, ultimatelyenhancing diagnostic accuracy in clinical applications.

The Application Value of Ultrasound Imaging in the Differential Diagnosis of Benign and Malignant Breast Nodules of BI-RADS 3 and Above

Objective:To explore the diagnostic value of ultrasound imaging for breast nodules of breast imaging-reporting and data system(BI-RADS)category 3 and above.Methods:From June 2021 to July 2022,163 patients with breast nodules of BI-RADS 3 or above were selected as the research subjects.After pathological diagnosis,24 cases were malignant breast nodules of BI-RADS 3 or above,while 139 cases were benign breast nodules of BI-RADS 3 or above.The diagnosis rate of malignant and benign breast nodules of BI-RADS 3 or above,including 95%CI,was observed and analyzed.Results:The malignant and benign detection rates of conventional ultrasound were 88.63%and 75.00%,respectively,and the malignant and benign detection rates of ultrasound imaging were 93.18%and 87.50%,respectively,with 95%CIs greater than 0.7.Conclusion:Ultrasound imaging can help improve the diagnostic accuracy of benign and malignant breast nodules of BI-RADS 3 and above and reduce the misdiagnosis rate.

Contrast-enhanced ultrasound Liver Imaging Reporting and Data System:Lights and shadows in hepatocellular carcinoma and cholangiocellular carcinoma diagnosis

BACKGROUND Contrast-enhanced ultrasound(CEUS)is considered a secondary examination compared to computed tomography(CT)and magnetic resonance imaging(MRI)in the diagnosis of hepatocellular carcinoma(HCC),due to the risk of misdiagnosing intrahepatic cholangiocarcinoma(ICC).The introduction of CEUS Liver Imaging Reporting and Data System(CEUS LI-RADS)might overcome this limitation.Even though data from the literature seems promising,its reliability in real-life context has not been well-established yet.AIM To test the accuracy of CEUS LI-RADS for correctly diagnosing HCC and ICC in cirrhosis.METHODS CEUS LI-RADS class was retrospectively assigned to 511 nodules identified in 269 patients suffering from liver cirrhosis.The diagnostic standard for all nodules was either biopsy(102 nodules)or CT/MRI(409 nodules).Common diagnostic accuracy indexes such as sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)were assessed for the following associations:CEUS LR-5 and HCC;CEUS LR-4 and 5 merged class and HCC;CEUS LR-M and ICC;and CEUS LR-3 and malignancy.The frequency of malignant lesions in CEUS LR-3 subgroups with different CEUS patterns was also determined.Inter-rater agreement for CEUS LI-RADS class assignment and for major CEUS pattern identification was evaluated.RESULTS CEUS LR-5 predicted HCC with a 67.6%sensitivity,97.7%specificity,and 99.3%PPV(P<0.001).The merging of LR-4 and 5 offered an improved 93.9%sensitivity in HCC diagnosis with a 94.3%specificity and 98.8%PPV(P<0.001).CEUS LR-M predicted ICC with a 91.3%sensitivity,96.7%specificity,and 99.6%NPV(P<0.001).CEUS LR-3 predominantly included benign lesions(only 28.8%of malignancies).In this class,the hypo-hypo pattern showed a much higher rate of malignant lesions(73.3%)than the iso-iso pattern(2.6%).Inter-rater agreement between internal raters for CEUS-LR class assignment was almost perfect(n=511,k=0.94,P<0.001),while the agreement among raters from separate centres was substantial(n=50,k=0.67,P<0.001).Agreement was stronger for arterial phase hyperenhancement(internal k=0.86,P<2.7×10-214;external k=0.8,P<0.001)than washout(internal k=0.79,P<1.6×10-202;external k=0.71,P<0.001).CONCLUSION CEUS LI-RADS is effective but can be improved by merging LR-4 and 5 to diagnose HCC and by splitting LR-3 into two subgroups to differentiate iso-iso nodules from other patterns.

Contrast-enhanced ultrasound improved performance of breast imaging reporting and data system evaluation of critical breast lesions

AIM: To determine whether contrast-enhanced ultrasound(CEUS) can improve the precision of breast imaging reporting and data system(BI-RADS) categorization. METHODS: A total of 230 patients with 235 solid breast lesions classified as BI-RADS 4 on conventional ultrasound were evaluated. CEUS was performed within one week before core needle biopsy or surgical resection and a revised BI-RADS classification was assigned based on 10 CEUS imaging characteristics. Receiver operating characteristic curve analysis was then conducted to evaluate the diagnostic performance of CEUS-based BI-RADS assignment with pathological examination as reference criteria. RESULTS: The CEUS-based BI-RADS evaluation classified 116/235(49.36%) lesions into category 3, 20(8.51%), 13(5.53%) and 12(5.11%) lesions into categories 4A, 4B and 4C, respectively, and 74(31.49%) into category 5. Selecting CEUS-based BI-RADS category 4A as an appropriate cut-off gave sensitivity and specificity values of 85.4% and 87.8%, respectively, for the diagnosisof malignant disease. The cancer-to-biopsy yield was 73.11% with CEUS-based BI-RADS 4A selected as the biopsy threshold compared with 40.85% otherwise, while the biopsy rate was only 42.13% compared with 100% otherwise. Overall, only 4.68% of invasive cancers were misdiagnosed.CONCLUSION: This pilot study suggests that evaluation of BI-RADS 4 breast lesions with CEUS results in reduced biopsy rates and increased cancer-to-biopsy yields.

Predictive model for contrast-enhanced ultrasound of the breast: Is it feasible in malignant risk assessment of breast imaging reporting and data system 4 lesions?

AIM: To build and evaluate predictive models for contrast-enhanced ultrasound(CEUS) of the breast to distinguish between benign and malignant lesions. METHODS: A total of 235 breast imaging reporting and data system(BI-RADS) 4 solid breast lesions were imaged via CEUS before core needle biopsy or surgical resection. CEUS results were analyzed on 10 enhancing patterns to evaluate diagnostic performance of three benign and three malignant CEUS models, with pathological results used as the gold standard. A logistic regression model was developed basing on the CEUS results, and then evaluated with receiver operating curve(ROC). RESULTS: Except in cases of enhanced homogeneity, the rest of the 9 enhancement appearances were statistically significant(P < 0.05). These 9 enhancement patterns were selected in the final step of the logistic regression analysis, with diagnostic sensitivity and specificity of 84.4% and 82.7%, respectively, and the area under the ROC curve of 0.911. Diagnostic sensitivity, specificity, and accuracy of the malignant vs benign CEUS models were 84.38%, 87.77%, 86.38% and 86.46%, 81.29% and 83.40%, respectively. CONCLUSION: The breast CEUS models can predict risk of malignant breast lesions more accurately, decrease false-positive biopsy, and provide accurate BIRADS classification.

Contrast-enhanced harmonic ultrasound imaging in ablation therapy for primary hepatocellular carcinoma

The success rate of percutaneous radiofrequency(RF)ablation for hepatocellular carcinoma(HCC)depends on correct targeting via an imaging technique.However,RF electrode insertion is not completely accurate for residual HCC nodules because B-mode ultrasound(US),color Doppler,and power Doppler US findings cannot adequately differentiate between treated and viable residual tumor tissue.Electrode insertion is also difficult when we must identify the true HCC nodule among many large regenerated nodules in cirrhotic liver.Two breakthroughs in the field of US technology,harmonic imaging and the development of second-generation contrast agents,have recently been described and have demonstrated the potential to dramatically broaden the scope of US diagnosis of hepatic lesions.Contrast-enhanced harmonic US imaging with an intravenous contrast agent can evaluate small hypervascular HCC even when B-mode US cannot adequately characterize tumor.Therefore,contrast-enhanced harmonic US can facilitate RF ablation electrode placement in hypervascular HCC,which is poorly depicted by B-mode US.The use of contrast-enhanced harmonic US in ablation therapy for liver cancer is an efficient approach.

Interobserver agreement for contrast-enhanced ultrasound of liver imaging reporting and data system:A systematic review and metaanalysis

BACKGROUND Hepatocellular carcinoma is the most common primary liver malignancy.From the results of previous studies,Liver Imaging Reporting and Data System(LIRADS)on contrast-enhanced ultrasound(CEUS)has shown satisfactory diagnostic value.However,a unified conclusion on the interobserver stability of this innovative ultrasound imaging has not been determined.The present metaanalysis examined the interobserver agreement of CEUS LI-RADS to provide some reference for subsequent related research.AIM To evaluate the interobserver agreement of LI-RADS on CEUS and analyze the sources of heterogeneity between studies.METHODS Relevant papers on the subject of interobserver agreement on CEUS LI-RADS published before March 1,2020 in China and other countries were analyzed.The studies were filtered,and the diagnostic criteria were evaluated.The selected references were analyzed using the“meta”and“metafor”packages of R software version 3.6.2.RESULTS Eight studies were ultimately included in the present analysis.Meta-analysis results revealed that the summary Kappa value of included studies was 0.76[95%confidence interval,0.67-0.83],which shows substantial agreement.Higgins I2 statistics also confirmed the substantial heterogeneity(I2=91.30%,95%confidence interval,85.3%-94.9%,P<0.01).Meta-regression identified the variables,including the method of patient enrollment,method of consistency testing,and patient race,which explained the substantial study heterogeneity.CONCLUSION CEUS LI-RADS demonstrated overall substantial interobserver agreement,but heterogeneous results between studies were also obvious.Further clinical investigations should consider a modified recommendation about the experimental design.

Hemodynamic Changes on Color Doppler Flow Imaging and Intravenous Contrast-enhanced Ultrasound for Assessing Transplanted Liver and Early Diagnosis of Complications

The value of color Doppler flow imaging （CDFI） and intravenous contrast-enhanced ultrasound （CEUS） for assessing the transplanted liver and early diagnosing complications by examining hemodynamic changes was discussed. Seventy-five patients with orthotopic liver transplantation （OLT） underwent CDFI. The following parameters were measured： peak systolic velocity （PS）, resistance index （RI） and Doppler perfusion index （DPI） of the hepatic artery （HA）, time average velocity （TAV） of portal vein （PV） and velocity of hepatic vein （HV） in different stages postoperation, And 11 patients of them received CEUS. Thirty healthy subjects were enrolled as controls, The results showed that： （1） In 23 patients without obvious complications, TAV of PV within 15 days post-operation was significantly higher than in controls （P〈0.05）, PS and DPI of HA within 7 days postoperation were lower, but RI was higher than in controls （P〈0.05）; （2） When the hepatic artery thrombosis （HAT） occurred, PS and DPI of HA were obviously decreased, but TAV of PV significantly increased like a high saw-tooth wave; （3） While rejection occurred, both TAV of PV and PS of HA were decreased with the increase in RI of HA, and the triphasic wave of HV disappeared and displayed as saw-tooth wave; （4） The incidence of biliary complications in liver transplantation was increased when DPI was reduced; （5） Seven cases of hepatic carcinoma relapse after OLT demonstrated hyperecho in the arterial phase and hypoecho in the portal and later phase on CEUS; （6） In 2 cases of HA thrombus, there was no visualized enhancement in arterial phase of CEUS, but enhancement during the portal vein and parenchymal phase. It was concluded that the hemodynamic changes of PV, HA and HV in the transplanted liver are valuable for assessing the transplanted liver and early diagnosing complications on CDFI and CEUS.

Gastrointestinal contrast-enhanced ultrasonography for diagnosis and treatment of peptic ulcer in children

BACKGROUND The detection rate of peptic ulcer in children is improving,with development of diagnostic procedures.Gastroscopy is the gold standard for the diagnosis of peptic ulcer,but it is an invasive procedure.Gastrointestinal contrast-enhanced ultrasonography(CEUS)has the advantages of being painless,noninvasive,nonradioactive,easy to use,and safe.AIM To investigate the clinical value of CEUS for diagnosis and treatment of peptic ulcer in children.METHODS We investigated 43 children with digestive tract symptoms in our hospital from January 2021 to June 2022.All children were examined by routine ultrasound,gastrointestinal CEUS,and gastroscopy.The pathological results of gastroscopy were taken as the gold standard.Routine ultrasonography was performed before gastrointestinal CEUS.Conventional ultrasound showed the thickness of the gastroduodenal wall,gastric peristalsis,and the adjacent organs and tissues around the abdominal cavity.Gastrointestinal CEUS recorded the thickness of the gastroduodenal wall;the size,location and shape of the ulcer;gastric peristalsis;and adjacent organs and tissues around the abdominal cavity.The results of routine ultrasound and gastrointestinal ultrasound were compared with those of gastroscopy to evaluate the diagnostic results and coincidence rate of routine ultrasound and gastrointestinal CEUS.All children received informed consent from their guardians for CEUS.This study was reviewed and approved by the hospital medical ethics committee.RESULTS Among the 43 children,17(15 male,2 female)were diagnosed with peptic ulcer by gastroscopy.There were 26 children with nonpeptic ulcer.There were eight cases of peptic ulcer and 35 of nonpeptic ulcer diagnosed by conventional ultrasound.The diagnostic coincidence rate of peptic ulcer in children diagnosed by conventional ultrasound was 79.1%(34/43),which was significantly different from that of gastroscopy(P=0.033).It indicates that the coincidence rate of gastrointestinal contrast-enhanced ultrasound and gastroscope is low.Fifteen cases of peptic ulcer and 28 of nonpeptic ulcer were diagnosed by CEUS.The diagnostic coincidence rate of peptic ulcer in children was 95.3%(41/43).There was no significant difference between CEUS and gastroscopy(P=0.655).It indicates that the coincidence rate of gastrointestinal contrast-enhanced ultrasound and gastroscope is high.CONCLUSION Gastrointestinal CEUS has a high coincidence rate in the diagnosis of peptic ulcer in children,and can be used as a preliminary examination method.

A Modified CycleGAN for Multi-Organ Ultrasound Image Enhancement via Unpaired Pre-Training

Handheld ultrasound devices are known for their portability and affordability,making them widely utilized in underdeveloped areas and community healthcare for rapid diagnosis and early screening.However,the image quality of handheld ultrasound devices is not always satisfactory due to the limited equipment size,which hinders accurate diagnoses by doctors.At the same time,paired ultrasound images are difficult to obtain from the clinic because imaging process is complicated.Therefore,we propose a modified cycle generative adversarial network(cycleGAN) for ultrasound image enhancement from multiple organs via unpaired pre-training.We introduce an ultrasound image pre-training method that does not require paired images,alleviating the requirement for large-scale paired datasets.We also propose an enhanced block with different structures in the pre-training and fine-tuning phases,which can help achieve the goals of different training phases.To improve the robustness of the model,we add Gaussian noise to the training images as data augmentation.Our approach is effective in obtaining the best quantitative evaluation results using a small number of parameters and less training costs to improve the quality of handheld ultrasound devices.

The Application Progress of Skin Imaging Technology in Psoriasis

Skin imaging technologies such as dermoscopy, high-frequency ultrasound, reflective confocal microscopy and optical coherence tomography are developing rapidly in clinical application. Skin imaging technology can improve clinical diagnosis rate, and its non-invasiveness and repeatability make it occupy an irreplaceable position in clinical diagnosis. With the “booming development” of medical technology, skin imaging technology can improve clinical diagnosis rate. Researchers have made significant advances in assisting clinical diagnosis, prediction, and treatment of disease. This article reviews the application and progress of skin imaging in the diagnosis of psoriasis.

Multi-modal imaging for the diagnosis of spontaneous visceral artery dissection:A case report

BACKGROUND Spontaneous visceral artery dissection(SVAD)is a rare condition that affects the visceral arteries,such as the celiac,superior mesenteric,and inferior mesenteric arteries,without involving the aorta.Organ ischemia or hemorrhage from vessel rupture can occur in SVAD;therefore,prompt detection and management is essential.Contrast-enhanced computed tomography(CECT)has been used to diagnose most of the previous cases,but few studies have explored the potential of contrast-enhanced ultrasound(CEUS)for early detection of this disease.CASE SUMMARY A 53-year-old male presented with complaints of poor appetite and abnormal liver function for the past 6 months.He had previously undergone transabdominal splenectomy,esophagogastric devascularization,and cholecystectomy for gallstones and severe portal hypertension.Liver ultrasound was performed in our department to assess liver status.An abnormal hepatic artery spectrum was observed,and dissection involving both the celiac artery and the common hepatic artery was observed.A CEUS was then performed and clearly showed the entry site of the intimal tear and the false lumen,and dissection was subsequently confirmed by CECT.The patient was asymptomatic;therefore,treatment to control the blood pressure was provided,and follow-up was recommended.After 6 months of follow-up,the celiac artery was found to be dilated with an adherent thrombus visible in the wall,and the common hepatic artery was occluded with the presence of collateralization.Despite these findings,no significant changes in liver function were observed.CONCLUSION Multi-modal imaging is effective in diagnosing SVAD,and conservative treatment is a choice for asymptomatic patients.

Value of contrast-enhanced ultrasound in deep angiomyxoma using a biplane transrectal probe:A case report

BACKGROUND Deep angiomyxoma(DAM)is a very rare tumor type.Magnetic resonance imaging(MRI)is considered the best imaging modality for diagnosing DAM.Computed tomography(CT)is used mainly to assess the invasion range of DAM.The value of ultrasonography in the diagnosis of DAM is still controversial.Through a literature review,we summarized the current state of ultrasonic examination for DAM and reported for the first time the contrast-enhanced ultrasound(CEUS)features of DAM seen using a biplane transrectal probe.CASE SUMMARY A 37-year-old woman presented with a sacrococcygeal mass that had gradually increased in size over the previous 6 mo.MRI and CT examinations failed to allow a definite diagnosis to be made.Transperineal core needle biopsy(CNB)guided by transrectal ultrasound and CEUS was suggested after a multidisciplinary discussion.Grayscale ultrasound of the lesion showed a layered appearance with alternating hyperechoic and hypoechoic patterns.Transrectal CEUS showed a laminated distribution of the contrast agent that was consistent with the layered appearance of the tumor on grayscale ultrasound.We performed transperineal CNB of the enhanced area inside the tumor under transrectal CEUS guidance and finally made a definitive diagnosis of DAM through histopathology.The patient underwent laparoscopic-assisted transabdominal surgery combined with transperineal surgery for large pelvic tumor resection and pelvic floor peritoneal reconstruction.No recurrence or metastasis was found at the ninemonth follow-up.CONCLUSION Transrectal CEUS can show the layered perfusion characteristics of the contrast agent,guiding subsequent transperineal CNB of the enhanced area within the DAM.

Recent Research Advances in Imaging of Prostate Cancer

Imaging study plays a crucial role in the diagnosis of prostate cancer. As early screening and management of prostate cancer has evolved over the past decade, research is now focusing on how to detect clinically significant prostate cancer and avoid overdiagnosis accurately. This article provides an overview of recent advances in imaging in prostate cancer diagnosis, including new ultrasound imaging techniques, positron emission computed tomography, multiparametric magnetic resonance imaging, and emerging areas such as imaging histology, by systematically reviewing and summarizing the existing literature.

Imaging and endoscopic tools in pediatric inflammatory bowel disease: What’s new?

Pediatric inflammatory bowel disease(IBD)is a chronic inflammatory disorder,with increasing incidence and prevalence worldwide.There have been recent advances in imaging and endoscopic technology for disease diagnosis,treatment,and monitoring.Intestinal ultrasound,including transabdominal,transperineal,and endoscopic,has been emerging for the assessment of transmural bowel inflammation and disease complications(e.g.,fistula,abscess).Aside from surgery,IBD-related intestinal strictures now have endoscopic treatment options including through-the-scope balloon dilatation,injection,and needle knife stricturotomy and new evaluation tools such as endoscopic functional lumen imaging probe.Unsedated transnasal endoscopy may have a role in patients with upper gastrointestinal Crohn’s disease or those with IBD with new upper gastrointestinal symptoms.Improvements to dysplasia screening in pediatric patients with longstanding colonic disease or primary sclerosing cholangitis hold promise with the addition of virtual chromoendoscopy and ongoing research in the field of artificial intelligence-assisted endoscopic detection.Artificial intelligence and machine learning is a rapidly evolving field,with goals of further personalizing IBD diagnosis and treatment selection as well as prognostication.This review summarized these advancements,focusing on pediatric patients with IBD.

Quantitative ultrasound brain imaging with multiscale deconvolutional waveform inversion

High-resolution images of human brain are critical for monitoring the neurological conditions in a portable and safe manner.Sound speed mapping of brain tissues provides unique information for such a purpose.In addition,it is particularly important for building digital human acoustic models,which form a reference for future ultrasound research.Conventional ultrasound modalities can hardly image the human brain at high spatial resolution inside the skull due to the strong impedance contrast between hard tissue and soft tissue.We carry out numerical experiments to demonstrate that the time-domain waveform inversion technique,originating from the geophysics community,is promising to deliver quantitative images of human brains within the skull at a sub-millimeter level by using ultra-sound signals.The successful implementation of such an approach to brain imaging requires the following items:signals of sub-megahertz frequencies transmitting across the inside of skull,an accurate numerical wave equation solver simulating the wave propagation,and well-designed inversion schemes to reconstruct the physical parameters of targeted model based on the optimization theory.Here we propose an innovative modality of multiscale deconvolutional waveform inversion that improves ultrasound imaging resolution,by evaluating the similarity between synthetic data and observed data through using limited length Wiener filter.We implement the proposed approach to iteratively update the parametric models of the human brain.The quantitative imaging method paves the way for building the accurate acoustic brain model to diagnose associated diseases,in a potentially more portable,more dynamic and safer way than magnetic resonance imaging and x-ray computed tomography.

Quantitative evaluation of colorectal tumour vasculature using contrast-enhanced ultrasound:Correlation with angiogenesis and prognostic significance

BACKGROUND Ultrasound is a vital tool for the diagnosis and management of colorectal cancer(CRC).Contrast-enhanced ultrasound(CEUS)is a non-invasive,safe,and cost-effective method for evaluating tumour blood vessels,that play a crucial role in tumour growth and progression.AIM To explore CEUS’s role in the quantitative evaluation of CRC blood vessels and their correlation with angiogenesis markers and prognosis.METHODS This study prospectively enrolled 100 patients with CRC confirmed by histo-pathology.All patients received preoperative CEUS examinations.Quantitative parameters,such as peak intensity(PI),time to peak(TTP),and area under the curve(AUC),were derived from time-intensity curve(TIC)analysis.Tumour tissue samples were obtained during surgery and examined immunohistochem-ically to assess the expression of angiogenesis markers,including vascular endo-thelial growth factor(VEGF)and microvessel density(MVD).The correlation between CEUS parameters,angiogenesis markers,and clinicopathological features was evaluated using appropriate statistical tests.RESULTS Quantitative CEUS parameters(PI,TTP,and AUC)showed significant correlations with VEGF expression(P<0.001)and MVD(P<0.001),indicating a strong link between tumour blood vessels and angiogenesis.Increased PI,reduced TTP,and expanded AUC values were significantly related to higher tumour stage(P<0.001),lymph node metastasis(P<0.001),and distant metastasis(P<0.001).Furthermore,these parameters were recognized as independent predictors of overall survival and disease-free survival in multivariate analysis(P<0.001).CONCLUSION CEUS has a high potential in guiding treatment planning and predicting patient outcomes.However,more com-prehensive,multicentre studies are required to validate the clinical utility of CEUS in CRC management.