Vascular Ultrasound Imaging Research Articles

Characteristics associated with anterior ischemic optic neuropathy (AION) in giant cell arteritis (GCA).

Giant cell arteritis (GCA) is the most common vasculitis and can result in blindness due to anterior ischemic optic neuropathy (AION). Little is known about which patients with GCA are at higher risk of AION.We did a retrospective chart review to compare demographics, past medical history, labs and imaging of GCA patients with and without AION. All patients at the University of Washington who were diagnosed with GCA by a rheumatologist, had a vascular ultrasound and met classification criteria for GCA were included. AION was diagnosed by an ophthalmologist. To compare demographics, symptoms, presentation imaging and lab findings, we used Pearson Chi-square, Fisher's exact test and t-tests to compare GCA patients with and without AION. 91 patients with GCA without vision loss were compared to 15 patients with GCA and AION.The AION group had significantly more men (p=0.03) and elevated C-reactive protein (CRP) as compared to the non-AION group (p = 0.04). Rates of hypertension, smoking, erythrocyte sedimentation rate (ESR) and classification scores were similar. Vascular ultrasound showed similar rates of small and large vessel vasculitis, but the AION group had higher halo scores, with the AION group having a mean score of 5 and patients with GCA and without AION having a mean score of 3 (p < 0.01). Older men with GCA and more than three halos on vascular ultrasound imaging of GC may be at higher risk of AION. Key Points • This is the first paper to incorporate the use of vascular ultrasound in comparing patients with anterior ischemic optic neuropathy (AION) to those without giant cell arteritis (GCA). • Male sex is associated with AION despite GCA being more common in women. • Older age and higher CRP are associated with AION. • GCA patients with AION had a higher halo score than GCA patients without AION.

Leiomyosarcoma of vascular origin: lessons learned from misdiagnosis

BackgroundLeiomyosarcoma (LMS) of vascular origin is a rare entity of soft tissue sarcomas. Although they arise mostly from retroperitoneal major vascular structures, some encountered cases may arise from the smaller vascular structures of the thigh as the femoral vein. Due to their origin from the vascular structures, they represent a diagnostic challenge as they may be misdiagnosed as deep vein thrombosis (DVT).Case presentationWe present a case of a 45-year-old woman with left femoral and iliac vein LMS that was previously described in the vascular ultrasound (US) report as extensive DVT involving the femoral and external iliac veins. The patient did not improve after receiving the prescribed anticoagulants. Seven months later, the patient underwent computerized tomography (CT) with contrast, revealing a soft tissue mass in the anatomical site of the left common femoral and external iliac veins. The patient underwent both US-guided tru-cut biopsy and incisional biopsy from the iliac lymph nodes which revealed leiomyosarcoma.Materials and methodsThe patient underwent both vascular ultrasound and magnetic resonance imaging of the pelvis and the left thigh at the time of the first presentation. Seven months later, she underwent contrast-enhanced CT of the abdomen and pelvis.OutcomeThe patient was referred to the oncology department to receive the appropriate chemotherapy protocol as the tumor was inoperable.ConclusionsAlthough leiomyosarcoma of vascular origin is a rare entity of neoplasms, it is usually underestimated. A high index of suspicion would help the clinician to suspect such a neoplasm and save time for early diagnosis and management. Special caution should be taken for patients with venous thrombosis not improving on anticoagulants. When there is suspicion, other modalities such as computerized tomography and magnetic resonance imaging help confirm the diagnosis.

US-Net: U-shaped network with Convolutional Attention Mechanism for ultrasound medical images

Ultrasound imaging, characterized by low contrast, high noise, and interference from surrounding tissues, poses significant challenges in lesion segmentation. To tackle these issues, we introduce an enhanced U-shaped network that incorporates several novel features for precise, automated segmentation. Firstly, our model utilizes a convolution-based self-attention mechanism to establish long-range dependencies in feature maps, crucial for small dataset applications, accompanied by a soft thresholding method for noise reduction. Secondly, we employ multi-sized convolutional kernels to enrich feature processing, coupled with curvature calculations to accentuate edge details via a soft-attention approach. Thirdly, an advanced skip connection strategy is implemented in the UNet architecture, integrating information entropy to assess and utilize texture-rich channels, thereby improving semantic detail in the encoder before merging with decoder outputs. We validated our approach using a newly curated dataset, VPUSI (Vascular Plaques Ultrasound Images), alongside the established datasets, BUSI, TN3K and DDTI. Comparative experiments on these datasets show that our model outperforms existing state-of-the-art techniques in segmentation accuracy.

The Value of Coagulation-Related Indicators Combined with Vascular Ultrasound Parameters in the Risk Assessment of Deep Vein Thrombosis after Secondary Traumatic Fracture Surgery.

The incidence of deep vein thrombosis (DVT) after traumatic fracture is high, and DVT causes serious adverse effects on the postoperative recovery of patients. The purpose of this study was to explore the effect of coagulation-related indicators combined with vascular ultrasound measurements for the risk assessment of DVT after secondary traumatic fracture, and to provide a new method for predicting the occurrence of DVT. The clinical data of patients with secondary traumatic fracture surgery in our hospital from January 2019 to January 2022 were retrospectively analyzed. The patients were divided into a non-DVT group and a DVT group according to whether DVT was indicated in the medical record system. The coagulation-related indices and vascular ultrasound measurements of the two groups were compared, and the risk factors for postoperative DVT were analyzed by bivariate correlation and multivariate logistic regression. According to the medical record system, 55 patients (47.41%) had DVT, and 61 patients (52.59%) did not have DVT. There was no significant difference in prothrombin time (PT) or activated partial thromboplastin time (APTT) between the two groups (p > 0.05). The thrombin time (TT) in the DVT group was lower than that in the non-DVT group. The levels of fibrinogen (FIB) and D-dimer (D-D) in the DVT group were higher than those in the non-DVT group (t = 2.766, 3.242, 2.649, p = 0.007, 0.002, 0.009). Spearman correlation analysis showed that peak systolic velocity (Vs), end-diastolic velocity (Vd), pulsatility index (PI), resistance index (RI), FIB, and D-D were positively correlated with the risk of DVT after secondary traumatic fracture surgery (r = 0.264, 0.656, 0.293, 0.276, 0.287, 0.251, p < 0.05). TT was negatively correlated with DVT risk after secondary traumatic fracture surgery (r = -0.249, p < 0.05). The measurements of peak systolic velocity (Vs), end diastolic velocity (Vd), pulsatility index (PI) and resistance index (RI) in the DVT group were higher than those in the non-DVT group (t = 2.663, 2.998, 3.135, 2.953, p = 0.009, 0.003, 0.002, 0.004). FIB, D-D, Vs, Vd, PI, and RI were independent risk factors for DVT after secondary traumatic fracture surgery (Odds Ratio (OR) = 1.483, 2.026, 2.208, 1.893, 1.820, 1.644, p < 0.05). TT index was an independent protective factor for DVT after secondary traumatic fracture surgery (OR = 0.868, p < 0.05). The sensitivity and specificity for prediction of DVT based on combined coagulation-related indicators and vascular ultrasound imaging measurements were higher than those of individual measurements (p < 0.05). Coagulation-related indicators and vascular ultrasound parameters can effectively predict the formation of DVT. Through the analysis of factors related to DVT formation, screening of high-risk patients for effective intervention may help to reduce the risk of DVT. Further verification in additional, large-scale clinical trials is advocated.

Enhancing Row-column array (RCA)-based 3D ultrasound vascular imaging with spatial-temporal similarity weighting.

Ultrasound vascular imaging (UVI) is a valuable tool for monitoring the physiological states and evaluating the pathological diseases. Advancing from conventional two-dimensional (2D) to three-dimensional (3D) UVI would enhance the vasculature visualization, thereby improving its reliability. Row-column array (RCA) has emerged as a promising approach for cost-effective ultrafast 3D imaging with a low channel count. However, ultrafast RCA imaging is often hampered by high-level sidelobe artifacts and low signal-to-noise ratio (SNR), which makes RCA-based UVI challenging. In this study, we propose a spatial-temporal similarity weighting (St-SW) method to overcome these challenges by exploiting the incoherence of sidelobe artifacts and noise between datasets acquired using orthogonal transmissions. Simulation, in vitro blood flow phantom, and in vivo experiments were conducted to compare the proposed method with existing orthogonal plane wave imaging (OPW), row-column-specific frame-multiply-and-sum beamforming (RC-FMAS), and XDoppler techniques. Qualitative and quantitative results demonstrate the superior performance of the proposed method. In simulations, the proposed method reduced the sidelobe level by 31.3 dB, 20.8 dB, and 14.0 dB, compared to OPW, XDoppler, and RC-FMAS, respectively. In the blood flow phantom experiment, the proposed method significantly improved the contrast-to-noise ratio (CNR) of the tube by 26.8 dB, 25.5 dB, and 19.7 dB, compared to OPW, XDoppler, and RC-FMAS methods, respectively. In the human submandibular gland experiment, it not only reconstructed a more complete vasculature but also improved the CNR by more than 15 dB, compared to OPW, XDoppler, and RC-FMAS methods. In summary, the proposed method effectively suppresses the side-lobe artifacts and noise in images collected using an RCA under low SNR conditions, leading to improved visualization of 3D vasculatures.

Contrast-Free High Frame Rate Ultrasound Imaging for Assessment of Vascular Remodeling During Wound Healing

BackgroundMonitoring of wound healing progression is critical due to the risk of infection, non-healing wounds, or evolution towards a chronic state. Tissue vasculature is one of the most representative features reflecting healing status. This study explores the feasibility of vascular ultrasound imaging of open wounds and the extraction of vascular-related features in a longitudinal study. Material and methodsC57BL/6 mice received a 1 cm-diameter full-thickness wound on their dorsum and were imaged using ultrasound from the surgical day (Day 0) to 25 days post-wounding. The high frame rate, plane waves acquisitions with a 15 MHz transducer were postprocessed with Singular Value Decomposition (SVD) filtering to provide vascular information. ResultsVascularity Index (VI) calculations showed an increased vascular signal in the wound from Day 2 post-wounding and were significantly higher from day 6 to day 10 post-wounding compared to Day 0 (p<0.05). VI values were back to the basal level after 3 weeks. In comparison, no significant difference was highlighted for the vascular signal in the peri-wound area. ConclusionsThese results show that vascular ultrasound imaging can be applied to track vascular changes of open wounds during the healing process. This approach may also be extended to other types of wounds for detecting early signs likely to cause complications.

Autonomous Robotic Ultrasound Vascular Imaging System With Decoupled Control Strategy for External-Vision-Free Environments.

Ultrasound (US) probes scan over the surface of the human body to acquire US images in clinical vascular US diagnosis. However, due to the deformation and specificity of different human surfaces, the relationship between the scan trajectory of the skin and the internal tissues is not fully correlated, which poses a challenge for autonomous robotic US imaging in a dynamic and external-vision-free environment. Here, we propose a decoupled control strategy for autonomous robotic vascular US imaging in an environment without external vision. The proposed system is divided into outer-loop posture control and inner-loop orientation control, which are separately determined by a deep learning (DL) agent and a reinforcement learning (RL) agent. First, we use a weakly supervised US vessel segmentation network to estimate the probe orientation. In the outer loop control, we use a force-guided reinforcement learning agent to maintain a specific angle between the US probe and the skin in the dynamic imaging processes. Finally, the orientation and the posture are integrated to complete the imaging process. Evaluation experiments on several volunteers showed that our RUS could autonomously perform vascular imaging in arms with different stiffness, curvature, and size without additional system adjustments. Furthermore, our system achieved reproducible imaging and reconstruction of dynamic targets without relying on vision-based surface information. Our system and control strategy provides a novel framework for the application of US robots in complex and external-vision-free environments.

B-ultrasound guided venipuncture vascular recognition system based on deep learning

Venipuncture is one of the common operations used by doctors in the outpatient blood drawing room. The success rate of puncture is not only related to the pain degree of the patient, but also affects the test results. In this study, we propose an ultrasound guided venipuncture vascular recognition system based on deep learning. First, kmeans++ clustering is performed for the vascular regions in the different B-mode ultrasound images to facilitate estimation in subsequent work. Second, a lightweight vascular ultrasound network (UV-YOLOv7) is designed, specifically, based on YOLOv7-tiny, a multi-scale feature fusion module (MFFM) is designed to better fuse the high-level semantic features and low-level detail features, and the speed and accuracy of model detection are enhanced by lightweighting the model structure and replacing the EIoU loss function. Finally, a Dynamic Neighborhood-Density Based Spatial Clustering of Applications with Noise (DN-DBSCAN) algorithm is proposed, which can cluster a series of local vascular regions using the localization results and confidence properties of the network output to remove the misdetected regions. In the experiment, We selected 303 artifact-free and 264 heavily artifacted vascular ultrasound images for offline expansion and trained on the experimental platform, The results show that the proposed method performed best with an mAP of 86.2% and an inference time of 0.6 ms. At the end of the experiment, more robust vascular localization results were obtained by DN-DBSCAN clustering.

Noninvasive Brachial Artery Mechanics and Endothelial Function

I t has been recognized that endothelial dysfunction is an early indication of Arterial disease. Endothelial function can be noninvasively evaluated by Inducing a temporary increase in blood flow and then observing the degree of vasodilation response or flow-mediated dilation. Impaired flow mediated vasodilation is then an indication of impaired endothelium. Vascular ultrasound Imaging has been the typical approach to access vasodilation by flow-mediated dilation most often at the brachial artery. Together with other measures of cardiovascular risk, the flow-mediated dilation response provides a very early noninvasive screen for cardiovascular disease. The skill and equipment required for brachial artery ultrasound imaging have limited the use of flow-mediated dilation as a routine medical test. Moreover, it has been recognized that other vascular parameters such as vessel size and blood pressure may influence the test itself. We have introduced a potential solution to the routine measurement of flow-mediated dilation by Analyzing the response of a simple occlusive arm cuff to obtain the Brachial Artery diameter in a noninvasive way. The analysis for occlusive cuff Plethysmography was provided here in a calibrated manner. This approach is an alternative to ultrasound flow-mediated dilation testing. It requires no special operator skills and may be automated for precision. Two experimental evaluations of the proposed cuff method are provided. First, The cuff- based brachial diameters were compared to Ultrasound obtained diameters. Second, as a sensitivity test, the cuff-based dilation test was used to measure the dilation response of several subjects to blood sugar loading. For further evaluation, the cuff-based measurements were applied to a mechanical model of the brachial artery to reveal a standard error of estimate less than 5%. The results show that the cuff-based diameters compare well to those obtained via ultrasound imaging. Moreover, the cuff-based dilation testing showed the expected reduction in endothelial function response due to a blood sugar load. Additionally, cuff-based flow-mediated dilation testing provides measurements as a function of the subject blood pressure, which Ultrasound generally cannot.

Differences in Carotid Artery Geometry and Flow Caused by Body Postural Changes and Physical Exercise.

Different body postures and physical exercises may lead to changes in arterial geometry and hemodynamics, which may be associated with the distribution of atherosclerosis lesions. This study was aimed at investigating potential geometric and hemodynamic changes of the carotid bifurcation in different body postures and after high-intensity interval training (HIIT) workouts. Three-dimensional vascular ultrasound (3DVUS) and Doppler ultrasound images were acquired for 21 healthy participants (aged 29 ± 6 y, 14 men and 7 women) in different body postures (sitting and three sleeping postures [supine, left lateral and right lateral]) and after physical exercises. The common carotid artery (CCA) and internal carotid artery (ICA) diameters of the left carotid artery were found to increase significantly from supine to left lateral (both p <0.05). CCA diameters (p < 0.05) and ICA/CCA diameter ratio (p < 0.01) of the left carotid artery changed significantly from supine to sitting. Significant differences in CCA peak systolic velocity (CCA PSV, p < 0.001), CCA end-diastolic velocity (CCA EDV, p < 0.001), CCA pulsatility index (CCA PI, p < 0.001) and maximum velocity-based wall shear stress at the CCA (WSS(max) at the CCA, p < 0.001) were identified in different postures. After physical exercises, significant increases were observed in the CCA diameter (p < 0.001), CCA PSV (p < 0.001), ICA PSV (p < 0.05), WSS(max) at the CCA (p < 0.001) and WSS(max) at the ICA (p < 0.05), as were significantly lower values of the CCA EDV (p < 0.01) and ICA/CCA PSV ratio (p < 0.05). Side-to-side differences were also detected in different postural change scenarios and after physical exercise; more significant differences were found to occur only in the left-sided carotid artery. Significant differences were identified under postural change and after physical exercise among healthy adults, suggesting that daily activity has an effect on the carotid bifurcation. These changes may be associated with formation and development of carotid atherosclerosis. Moreover, these side differences might be severe for patients and worth further attention in clinical practice.

Ultrasound quantitative assessment of ventral finger microvasculopathy in systemic sclerosis with Raynaud’s phenomena: a comparative study

ObjectiveTo assess the finger vascularity of systemic sclerosis patients with Raynaud’s phenomenon (RP-SSc) using various ultrasound techniques.MethodsAll fingers (except thumbs) of 18 RP-SSc patients and 18 controls were imaged at...

Integration of multimedia components into the models of treatment and diagnostic process in patients and clinical diagnostic tasks in cardiology

Introduction. Integration of multimedia results of diagnostic examinations into the information model of diagnostic and treatment process makes it possible to teach medical decision-making taking into account all available information about the patient.Aim. The purpose of this work was to use multimedia results of instrumental examination methods to form and verify the level of effective diagnostic decision-making.Material and Methods. A significant array of multimedia information arising in the course of treatment and diagnostic process was derived from databases of diagnostic units and was important for medical decision-making. The model was supplemented with clinically and demographically relevant studies of other patients when necessary. The multimedia components were integrated into the virtual simulations with two different trajectories of information presentation to the trainees depending on the purpose of further use.Results. At the first stage of the project, the multimedia components were integrated into linear models of completed cases to demonstrate medical decisions to the trainees. The multimedia components were presented as the fragments of magnetic resonance imaging (MRI) data, echocardiography and vascular ultrasound recordings, scanned electrocardiograms (ECG), angiography results, X-ray images, tomograms, and results of other visualization methods of patient examination. Each multimedia file was accompanied by a textual conclusion made by a relevant specialist. At the second stage, the multimedia components were integrated into the models with a branched trajectory of information presentation. The course of disease and the patient’s condition could change depending on the decisions made, which means that there are alternative scenarios of the therapeutic and diagnostic process unlike the real invariant treatment of the patient. This possibility is especially important for the formation of medical decision-making competencies in safe conditions of simulation. To elaborate clinical diagnostic tasks, the authors developed a rating system quantifying the effectiveness of the decisions.Discussion. Building physician competencies in the educational process through repeated decision-making under changing conditions is crucially important for the health and lives of patients and can be effectively implemented using simulation technologies. Web access to this content is strategically important for the use of virtual patients with multimedia diagnostic results to practice decision-making skills in clinical disciplines.

New 3-Dimensional Volumetric Ultrasound Method for Accurate Quantification of Atherosclerotic Plaque Volume

BackgroundCarotid and femoral plaque burden is a recognized biomarker of cardiovascular disease risk. A new electronic-sweep 3-dimensional (3D)–matrix transducer method can improve the functionality and image quality of vascular ultrasound atherosclerosis imaging. ObjectivesThis study aimed to validate this method for plaque volume measurement in early and intermediate–advanced plaques in the carotid and femoral territories. MethodsPlaque volumes were measured ex vivo in pig carotid and femoral artery specimens by 3-dimensional vascular ultrasound (3DVUS) using a 3D-matrix (electronic-sweep) transducer and its associated 3D plaque quantification software, and were compared with gold-standard histology. To test the clinical feasibility and accuracy of the 3D-matrix transducer, an experiment was conducted in intermediate–high risk individuals with carotid and femoral atherosclerosis. The results were compared with those obtained using the previously validated mechanical-sweep 3D transducer and established 2-dimensional (2D)–based plaque quantification software. ResultsIn the ex vivo study, the authors assessed 19 atherosclerotic plaques (plaque volume, 0.76 µL-56.30 μL), finding strong agreement between measurements with the 3D-matrix transducer and the histological gold-standard (intraclass correlation coefficient [ICC]: 0.992; [95% CI: 0.978-0.997]). In the clinical analysis of 20 patients (mean age 74.6 ± 4.45 years; 40% men), the authors found 64 (36 carotid and 28 femoral) of 80 scanned territories with atherosclerosis (measured atherosclerotic volume, 10 μL-859 μL). There was strong agreement between measurements made from electronic-sweep and mechanical-sweep 3DVUS transducers (ICC: 0.997 [95% CI: 0.995-0.998]). Agreement was also high between plaque volumes estimated by the 2D and 3D plaque quantification software applications (ICC: 0.999 [95% CI: 0.998-0.999]). Analysis time was significantly shorter with the 3D plaque quantification software than with the 2D multislice approach with a mean time reduction of 46%. Conclusions3DVUS using new matrix transducer technology, together with improved 3D plaque quantification software, simplifies the accurate volume measurement of early (small) and intermediate–advanced plaques located in carotid and femoral arteries.

Target organ damage in relation to intensity of cigarette smoking, statin therapy and the endogenous testosterone in middle aged hypertensive men with erectile dysfunction

Abstract Background Target organ damage (TOD) amplifies cardiovascular risk in essential hypertension. Erectile dysfunction (ED) refers to microvascular disease and frequently accompanies the hypertensive middle aged male population. Endogenous testosterone (TT) and statins exhibit vasoprotective effects while cigarette smoking typically relates to an adverse cardiovascular outcome. Purpose To investigate TOD in relation to cigarette smoking, statin therapy and TT in essential hypertension middle aged males with ED. Methods 223 hypertensive ED males (mean age: 59 yo) with no history of diabetes mellitus or overt cardiovascular disease enrolled the study. There were all screened for the presence of microalbuminuria, defined as urinary albumin loss 30 – 300 mg in a 24 h urine volume collection. Among them 96 (43%) were current cigarette smokers. Intensity of smoking referred in terms of packs per year. The presence and severity of ED was assessed by the SHIM-5 score (range 0–25), higher values indicate better erectile ability. All underwent a non invasive evaluation of the carotid – femoral pulse wave velocity (PWV), estimation of central pressures and augmentation index (AIx) a parameter of wave reflection amplification (Sphygmocor device).Moreover left ventricular mass index (LVMI) was assessed by 2D echocardiography (Devereux formula) and intima-media thickness (cIMT) of the common carotid artery by vascular ultrasound imaging. cIMT is a marker of atheromatosis. Results Microalbuminuria detected in 89 (40%) patients was positively related to other parameters of TOD such as PWV, cIMT, LVMI (all p&amp;lt;0,005) and smoking habits (p=0,02) and negatively to the SHIM-5 score, TT and statin use (all p&amp;lt;0,01). A notably negative correlation to the intensity of smoking was the SHIM-5 score (p=0,013) and a positive the cIMT (p=0,001). Statins were positively related to TT (p=0,006).In linear regression analysis, relation of packs per year remained significant regarding microalbuminuria and the SHIM-5 after adjustment for age, body mass index, PWV, LVMI, central systolic, diastolic and pulse blood pressure. Similarly, relation of statins, TT and microalbuminuria remained significant after adjustment for age, LVMI, PWV, AIx and smoking status. Conclusion Intensive cigarette smoking accelerates silent kidney damage and sabotages erectile performance in hypertensive middle aged men with ED independently of the central hemodynamic load. Statins protect from microvascular kidney damage and the decline of testosterone probably by enhancing endothelial physiology. In such population group, simple and clinically oriented criteria may reveal early diagnosis of target organ damage and guide appropriate life-style modifications and further therapeutic judgments. Funding Acknowledgement Type of funding sources: None. Figure 1

Recent advances in vascular ultrasound imaging technology and their clinical implications

In this paper recent advances in vascular ultrasound imaging technology are discussed, including three-dimensional ultrasound (3DUS), contrast-enhanced ultrasound (CEUS) and strain- (SE) and shear-wave-elastography (SWE). 3DUS imaging allows visualisation of the actual 3D anatomy and more recently of flow, and assessment of geometrical, morphological and mechanical features in the carotid artery and the aorta. CEUS involves the use of microbubble contrast agents to estimate sensitive blood flow and neovascularisation (formation of new microvessels). Recent developments include the implementation of computerised tools for automated analysis and quantification of CEUS images, and the possibility to measure blood flow velocity in the aorta. SE, which yields anatomical maps of tissue strain, is increasingly being used to investigate the vulnerability of the carotid plaque, but is also promising for the coronary artery and the aorta. SWE relies on the generation of a shear wave by remote acoustic palpation and its acquisition by ultrafast imaging, and is useful for measuring arterial stiffness. Such advances in vascular ultrasound technology, with appropriate validation in clinical trials, could positively change current management of patients with vascular disease, and improve stratification of cardiovascular risk.

Familial Hypercholesterolemia: Global Burden and Approaches.

Familial hypercholesterolemia (FH) is the most common genetic metabolic disorder characterized by markedly elevated LDL-C levels from birth leading to atherosclerotic cardiovascular disease (ASCVD) and premature deaths. The purpose of this review is to share the current knowledge in the diagnosis, risk estimation, and management of patients with FH in the light of recent evidence and guideline recommendations. Recent registries underscored the prevalence of FH as 1/200-250 translating to an almost 1500 million subjects suffering from FH worldwide. However, only a minority of FH patients are identified early and effectively treated. In most cases, mutations in the LDL-receptor (LDLR) gene and to a lesser degree in the apolipoprotein B-100 (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and the LDL-receptor adaptor protein 1 (LDLRAP1) genes cause FH. Diagnostic scores such as Dutch Lipid Clinic Network criteria using clinical manifestations are helpful in identifying FH. Traditional risk factors and high lipoprotein(a) affect the course of the disease. Vascular ultrasound imaging and coronary calcium scoring are helpful for further risk estimation of these patients. Getting to LDL-C goals is possible with currently available treatments including statins, ezetimibe, and PCSK9 inhibitors, as well as lipoprotein apheresis, lomitapide, and mipomersen in more severe phenotypes. Additionally, novel agents bempedoic acid, inclisiran, and evinacumab expanded the treatment choices for some patients with FH. Early diagnosis and initiation of LDL-C lowering are still required to achieve the greatest reduction in ASCVD morbidity and mortality in patients with FH. FH is a common genetic disorder characterized by markedly elevated LDL-C levels from birth onward, resulting in significantly increased risk for ASCVD. Despite major advances in our understanding of the disease and effective therapies, FH is still underdiagnosed and undertreated. Early initiation of LDL-C lowering by increased awareness of FH among the healthcare professionals, patients, and the public is necessary to achieve meaningful reduction in ASCVD morbidity and mortality in these patients.

Detecting High-Resolution Intramural Vascular Wall Strain Signals Using DICOM Data.

Maintaining dialysis vascular access is a source of considerable morbidity in patients with end-stage renal disease (ESRD). High-resolution radiofrequency (RF) ultrasound vascular strain imaging has been applied experimentally in the vascular access setting to assist in diagnosis and management. Unfortunately, high-resolution RF data are not routinely accessible to clinicians. In contrast, the standard DICOM formatted B-mode ultrasound data are widely accessible. However, B-mode, representing the envelope of the RF signal, is of much lower resolution. If strain imaging could use open-source B-mode data, these imaging techniques could be more broadly investigated. We conducted experiments to detect wall strain signals with submillimeter tracking resolutions ranging from 0.2 mm (3 pixels) to 0.65 mm (10 pixels) using DICOM B-mode data. We compared this submillimeter tracking to the overall vascular distensibility as the reference measurements to see if high-strain resolution strain could be detected using open-source B-Mode data. We measured the best-fit coefficient of determination between signals, expressed as the percentage of strain waveforms that exhibited a correlation with a p value of 0.05 or less. The lowest percentage was 86.7%, and most were 90% and higher. This indicates high-resolution strain signals can be detected within the vessel wall using B-mode DICOM data.

Simultaneous Noise Suppression and Incoherent Artifact Reduction in Ultrafast Ultrasound Vascular Imaging.

Ultrasound vascular imaging based on ultrafast plane wave imaging and singular value decomposition (SVD) clutter filtering has demonstrated superior sensitivity in blood flow detection. However, ultrafast ultrasound vascular imaging is susceptible to electronic noise due to the weak penetration of unfocused waves, leading to a lower signal-to-noise ratio (SNR) at larger depths. In addition, incoherent clutter artifacts originating from strong and moving tissue scatterers that cannot be completely removed create a strong mask on top of the blood signal that obscures the vessels. Herein, a method that can simultaneously suppress the background noise and incoherent artifacts is proposed. The method divides the tilted plane or diverging waves into two subgroups. Coherent spatial compounding is performed within each subgroup, resulting in two compounded data sets. An SVD-based clutter filter is applied to each data set, followed by a correlation between the two data sets to produce a vascular image. Uncorrelated noise and incoherent artifacts can be effectively suppressed with the correlation process, while the coherent blood signal can be preserved. The method was evaluated in wire-target simulations and phantom, in which around 7-10-dB SNR improvement was shown. Consistent results were found in a flow channel phantom with improved SNR by the proposed method (39.9 ± 0.2 dB) against conventional power Doppler (29.1 ± 0.6 dB). Last, we demonstrated the effectiveness of the method combined with block-wise SVD clutter filtering in a human liver, breast tumor, and inflammatory bowel disease data sets. The improved blood flow visualization may facilitate more reliable small vessel imaging for a wide range of clinical applications, such as cancer and inflammatory diseases.

High-Frequency Array-Based Nanobubble Nonlinear Imaging in a Phantom and In Vivo.

There has been growing interest in nanobubbles (NBs) for vascular and extravascular ultrasound contrast imaging and therapeutic applications. Studies to date have generally utilized low frequencies (<12 MHz), high concentrations (>109 mL-1), and uncalibrated B-mode or contrast-mode on commercial systems without reporting investigations on NB signatures upon which the imaging protocols should be based. We recently demonstrated that low concentrations (106 mL-1) of porphyrin-lipid-encapsulated NBs scatter nonlinearly at low (2.5, 8 MHz) and high (12.5, 25, 30 MHz) frequencies in a pressure threshold-dependent manner that is advantageous for amplitude modulation (AM) imaging. Here, we implement pressure-calibrated AM at high frequency on a commercial preclinical array system to enhance sensitivity to nonlinear scattering of three phospholipid-based NB formulations. With this approach, improvements in contrast to tissue ratio relative to B-mode between 12.4 and 22.8 dB are demonstrated in a tissue-mimicking phantom, and between 6.7 and 14.8 dB in vivo.

Diagnostic accuracy of ultrasound superb microvascular imaging for focal liver lesions

Background:Superb microvascular imaging (SMI) is a new ultrasound vascular imaging technology, which uses a new Doppler algorithm, it has the characteristics of high sensitivity and high resolution to detect low velocity blood flow; it is easier to detect microvessels with low-velocity flow compared with color Doppler flow imaging in theory; and it can image the microvessels of the lesion without angiography.[1] Previous studies showed that SMI can detect tumor neovascularization to differentiate benign from malignant focal liver lessions (FLLs). However, the results of these studies have been contradictory with low sample sizes. This meta-analysis tested the hypothesis that SMI is accurate in distinguishing benign and malignant FLLs.Methods:We will search PubMed, Web of Science, Cochrane Library, and Chinese biomedical databases from their inceptions to the November 30, 2020, without language restrictions. Two authors will independently carry out searching literature records, scanning titles and abstracts, full texts, collecting data, and assessing risk of bias. Review Manager 5.2 and Stata14.0 software will be used for data analysis.Results:This systematic review will determine the accuracy of SMI in the differential diagnosis between benign and malignant FLLs.Conclusion:Its findings will provide helpful evidence for the accuracy of SMI in the differential diagnosis between benign and malignant FLLs.Systematic review registration:INPLASY2020120081.