This study evaluates the performance of subharmonic-aided pressure estimation (SHAPE) with ultrasound contrast agents using data obtained from calibration procedures. A commercial scanner of ultrasonography (GE Healthcare Logiq E20, Wuxi, China) was used to perform SHAPE on a flowing contrast agent (Sonazoid) in a phantom setup under controlled microbubble stability and flow velocity conditions. Subharmonic time-intensity curves were collected during the SHAPE calibration procedure for analysis. Subharmonic amplitude of diluted contrast agents exhibited a time-dependent decline but was not affected by velocity. SHAPE sensitivity was measured through reciprocal pressurizing and depressurizing sequences to mitigate the effect of subharmonic decline over time. A wide range of mechanical index (MI) levels within the steady growth phase of the calibration curve showed higher SHAPE sensitivity compared to the traditionally recommended “optimal” MI at the maximum slope. The approximate maximum SHAPE sensitivity was −0.04 dB/mm Hg. Subharmonic amplitude was linearly correlated with pressure at a range of MI levels (R2 > 0.9, p < 0.05) but showed significant variations (approximately 2 dB standard deviation) in the time series. The lowered sensitivity compared to previous reports, combined with the substantial variation in subharmonic amplitude, raises concerns about the accuracy and consistency of SHAPE in clinical applications.

Background: Subharmonic aided pressure estimation (SHAPE) is an innovative non-invasive technique that leverages ultrasound subharmonic imaging to estimate pressure. This method exploits the "negative correlation between subharmonic amplitude and ambient pressure" observed in experimental settings. Despite extensive experimental validation and some promising results in clinical studies, the underlying mechanism of SHAPE remains incompletely understood. Although some studies have attempted to provide theoretical explanations, definitive conclusions have yet to be reached. In addition, theoretical investigations have mainly focused on the steady oscillation of bubbles under long pulse excitation, which contrasts with the short pulse excitation required for clinical SHAPE applications. An understanding of the SHAPE principle under short pulse excitation is needed. Methods: The exponential elasticity model (EEM) was used to simulate Sonazoid bubbles, and a probe-to-probe acoustic propagation model was introduced to mimic a practical SHAPE scenario. The simulated acoustic signals in response to three-cycle sinusoidal pulse excitations were analyzed for spectral composition. The relationship between microbubble oscillation patterns and subharmonic characteristics was identified through detailed investigation. Results: For the excitation pulse of 2.5 MHz frequency and 350 kPa magnitude, bubbles larger than the resonance radius (2.29 mu m) exhibited significant subharmonics in the magnitude spectrum, while bubbles smaller than the subharmonic resonance radius (3.85 mu m) showed the activity of scattering subharmonic energy and the sensitivity to ambient pressure. The emergence of subharmonics when increasing excitation power was related to the increasing amplification of the bubble self-oscillation and the period-doubling features in the acoustically forced oscillation. The negative correlation between subharmonic amplitude and ambient pressure was attributed to the reduced self-oscillation caused by increasing ambient pressure and hence bubble size reduction. Microbubbles falling between 2 and 3 mu m showed the desired subharmonic sensitivity to ambient pressure under the specified excitation conditions. Conclusion: The transient oscillatory behavior of microbubbles in response to short pulse excitation, characterized by a ringing down self-oscillation after the acoustic forcing effect has ceased, is crucial for understanding the subharmonic emergence and the observed negative correlation between subharmonic amplitude and ambient pressure. The proposed concepts of subharmonic resonance radius, subharmonic-significant bubbles, and subharmonic-active bubbles provide valuable insights into the diverse subharmonic behavior of microbubbles. The theoretical explanation of this negative correlation highlights the importance of using subharmonicsignificant-and-active bubbles for SHAPE applications.

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

OBJECTIVE:To optimize cut-off values of endometrial thickness for referral to hysteroscopy among asymptomatic postmenopausal women with thickened endometrium. DESIGN:A retrospective observational analysis. SETTING:A teaching hospital. PATIENTS:415 asymptomatic postmenopausal cases who underwent hysteroscopy with thickened endometrium between January 2014 to January 2023. INTERVENTIONS:Patients with endometrium thicker than 5mm underwent hysteroscopy for endometrial pathological examination. MEASUREMENTS:Transvaginal sonography (TVS) reports of 37732 patients who had ET ≥ 5mm were reviewed. Among them, 415 patients were postmenopausal and asymptomatic. Their clinical characteristics were analyzed retrospectively, including demographic data, TVS reports, hysteroscopy surgery records, and pathology results. RESULTS:Endometrial thickness significantly differed between patients whose samples were pathologically benign and those who turned out premalignant or malignant (χ2 = 70.7, P < .001). The observed endometrial morphology during hysteroscopy varied notably between these groups (χ2 = 33.3, p < .001). Logistic regression revealed significant associations between treatment by Selective Estrogen Receptor Modulator (SERM; OR = 3.2, p = .04), increased endometrial thickness (OR = 3.7, p < .001), and abnormal endometrial morphology (OR = 3.4, p < .001) with non-benign outcomes. To differentiate for non-benign pathology, the optimal endometrial thickness cut-offs were 10.5mm for all asymptomatic patients with thickened endometrium, 10.5mm for those with concurrent intrauterine lesions, and 19.5mm for those with a history of SERM treatment. CONCLUSIONS:Increasing the endometrial thickness cut-off value in asymptomatic postmenopausal women, especially for those with a history of SERM treatment, would improve patient management.

Objective: This study aimed to investigate the impact of microbubble degradation and flow velocity on Sub-Harmonic Aided Pressure Estimation (SHAPE), and to explore the correlation between subharmonic amplitude and pressure as a single factor. Methods: We develop an open-loop vascular phantom platform system and utilize a commercial ultrasound machine and microbubbles for subharmonic imaging. Subharmonic amplitude was measured continuously at constant pressure and flow velocity to assess the impact of microbubble degradation. Flow velocity was varied within a range of 4-14 cm/s at constant pressure to investigate its relationship to subharmonic amplitude. Furthermore, pressure was varied within a range of 10-110 mm Hg at constant flow velocity to assess its isolated effect on subharmonic amplitude. Results: Under constant pressure and flow velocity, subharmonic amplitude exhibited a continuous decrease at an average rate of 0.221 dB/min, signifying ongoing microbubble degradation during the experimental procedures. Subharmonic amplitude demonstrated a positive correlation with flow velocity, with a variation ratio of 0.423 dB/(cm/s). Under controlled conditions of microbubble degradation and flow velocity, a strong negative linear correlation was observed between pressure and subharmonic amplitude across different Mechanical Index (MI) settings (all R-2 > 0.90). The sensitivity of SHAPE was determined to be 0.025 dB/mmHg at an MI of 0.04. Conclusion: The assessment of SHAPE sensitivity is affected by microbubble degradation and flow velocity. Excluding the aforementioned influencing factors, a strong linear negative correlation between pressure and subharmonic amplitude was still evident, albeit with a sensitivity coefficient lower than previously reported values.

Intravenous leiomyomatosis (IVL) is a rare gynecological-related tumor. It can invade and extend in the blood vessel and eventually involve the cardiac cavity or even the pulmonary artery. IVL generally does not adhere to the vein wall and infrequently leads to the manifestation of Budd-Chiari syndrome (BCS). In this case report, the presence of a sizable tumor obstructed the second hepatic portal, impeding the return flow of the hepatic veins, thereby precipitating the development of BCS. The presence of collateral veins and dilation of the accessory hepatic vein were identified through computed tomography venography and ultrasonography, thus supporting the diagnosis of BCS. The patient underwent a comprehensive surgical resection and was found to have a favorable prognosis.

ABSTRACT Objectives To evaluate the efficacy of ultrasound and contrast-enhanced ultrasound (CEUS) in disease activity assessment of Takayasu arteritis (TA) with carotid involvement. Methods This is a cohort study of 115 patients of TA with carotid involvement. We investigated correlations between clinical data, sonographic features, and CEUS enhancement at the site most prominent lesion of each patient. Disease activity was assessed by the National Institute of Health Kerr criteria. Sonographic findings were compared with follow-up examinations. CEUS was repeated after a 3–7 months interval in 35 patients to evaluate change of CEUS enhancement after treatment. Results Extensiveness of CEUS enhancement at most prominent carotid lesions had significant correlations with disease activity by the Kerr criteria (P < .001). The specificity of extensive enhancement for indicating active disease was 95%, while sensitivity was 67%. Patients with active disease showed greater arterial wall thickness and more prominent reduction of arterial wall thickness after treatment. Most of the patients (68%) with subsided active disease after treatment featured decrease of CEUS enhancement. Conclusions Extensiveness of enhancement by CEUS and arterial wall thickness by ultrasonography may be useful markers for initial and follow-up assessment of disease activity of TA with common carotid artery involvement.

Background A virilizing ovarian tumor (VOT) is a rare cause of hyperandrogenism in pre- and postmenopausal women. Although transvaginal ultrasound is considered as the first-line imaging method for ovarian tumors, it is examiner-dependent. We aimed to summarize the clinical and ultrasound manifestations of VOTs to help establish the diagnosis with emphasis on those causing diagnostic difficulty. Method We retrospectively identified 31 patients with VOTs who underwent surgery at Peking Union Medical College Hospital. Results Patients with VOTs were predominantly premenopausal. All patients showed androgenic manifestations with serum testosterone levels elevated to varying degrees. The tumor size of VOTs was significantly correlated with age ( P < 0.001). The VOTs in the postmenopausal group were significantly smaller than those in the premenopausal group (median 1.8 cm [range, 1.3–4.8 cm] vs 4.5 cm [range, 0.7–11.9 cm]; P = 0.018). Twenty-seven out of 31 VOTs were successfully identified by ultrasound. On ultrasound, VOTs are mostly solid and hypoechoic masses with enhanced vascularity. Four VOTs (0.7–1.5 cm) were radiologically negative, and they were the smallest among all patients. Conclusion Patients with VOTs showed androgenic manifestations with varying degrees of hyperandrogenemia. Older patients tend to have smaller VOTs. Ultrasound is an effective method for the detection of VOTs. Some VOTs can be very small and difficult to visualize radiologically, especially in postmenopausal patients. Examiners must remain vigilant about very small VOTs on the basis of endocrine symptoms.

Objective:To make a survey of the job tasks of China's ultrasound residents, in order to provide a basis for improving the standardized training program for ultrasound residents and the design of final examination.Methods:We first established a job task list for ultrasound residents to reflect their clinical work, scientific research training, and ability training needed in their actual work. A total of 1369 residents from 11 provinces who have completed the standardized residential ultrasound training program were enrolled in the study. A stratified sampling investigation was conducted according to the proportion of residents by province. The frequency and importance of each job task in the current work and during the residence training period were investigated, and the comprehensive score of each task was calculated. Kappa consistency test was used to evaluate the consistency between the task frequency in the current work and during the training period.Results:The task list of ultrasound residents included 18 job tasks, of which the top five with the highest comprehensive score were: abdominal and pleural effusion ultrasound, standardized writing of ultrasound report, superficial organ ultrasound, peripheral blood vessel ultrasound, and obstetrics and gynecology ultrasound. The frequency of each job task in the current work and during the residence training period had a moderate consistency (Kappa=0.477~0.580, P＜0.001). The top three tasks with the largest difference were emergency ultrasound (3.88 vs 3.34), obstetrics and gynecology ultrasound (4.00 vs 3.69), and peripheral vascular ultrasound (4.08 vs 3.87), which were performed more frequently in the current work than in the training period. The frequency consistency of job task assisting interventional ultrasound between actual work and residential training was poor (Kappa=0.200, P＜0.001), and the current frequency was significantly lower than that during residential training (1.67 vs 2.87).Conclusion:There is a moderate consistency for the frequency of most job tasks between current work and the training period. The assessment of job tasks could provide a basis for formulating the final examination of residency training program. It is suggested that the training for emergency ultrasound, obstetrics and gynecology ultrasound, and peripheral vascular ultrasound should be enhanced during residency training period, and the proportion of interventional ultrasound be reduced in the final examination.

探索超声临床博士后核心胜任力的360度评估方法,以补充完善超声临床博士后评价反馈体系.方法根据住院医师核心胜任力要求,结合超声专业特点,制定出适用于超声住院医师的临床胜任力360度评价体系,并在北京协和医院第1批超声临床博士后中开展临床实践.将3位超声临床博士后3年的动态评估结果进行对比分析,探讨该评价体系的评估效果.结果3位超声临床博士后的总体胜任力评分较高,并呈逐年上升趋势,同时各核心胜任力评分逐渐平衡,提示经过3年培训,6大核心胜任力逐渐完善并全面发展,符合教学规律.另外,评估结果显示各博士后的临床胜任力有共性特征,又表现出个性化特点.结论超声专业临床胜任力360度评估体系能够多方面的评估超声临床博士后的核心胜任力,可作为临床博士后评价反馈体系的有效组成部分,也值得在超声住院医师规范化培训中进行尝试和推广.

Background Evidence of the association between serum lipid profiles and intraplaque neovascularization (IPN) is still limited. We aimed to study the value of a novel Doppler method, superb microvascular imaging, in correlating serum lipid profiles and evidence of IPN in a population with a high risk of stroke. Methods and Results A community‐based cross‐sectional study was conducted in Beijing, China. Residents (aged ≥40 years) underwent questionnaire interviews, physical examinations, and laboratory testing in 2018 and 2019. Subjects with a high risk of stroke were then selected. Standard carotid ultrasound and carotid plaque superb microvascular imaging examinations were then performed on the high–stroke‐risk participants. Logistic regression was used to evaluate the relationship between serum lipid profiles and carotid plaque IPN. Overall, a total of 250 individuals (mean age, 67.20±8.12 years; 66.4% men) met the study inclusion criteria. Superb microvascular imaging revealed carotid plaque IPN in 96 subjects (38.4%). Subjects with IPN were more likely to be current smokers (34.0% versus 46.9%, P=0.046), and their identified carotid plaques were much thicker (2.35±0.63 mm versus 2.75±0.80 mm, P=0.001). Serum lipids, including total cholesterol, non–high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol were positively associated with the presence of IPN (4.33±1.00 mmol/L versus 4.79±1.12 mmol/L, P=0.001; 2.96±0.92 mmol/L versus 3.40±1.01 mmol/L, P=0.001; 2.18±0.76 mmol/L versus 2.46±0.80 mmol/L, P=0.005, respectively), and after adjustment for other confounders, the positive relationship remained significant. Furthermore, non–high‐density lipoprotein cholesterol (odds ratio, 2.62 [95% CI, 1.35–5.06]) was significantly associated with the presence of carotid plaque IPN even after adjusting for low‐density lipoprotein cholesterol. Conclusions Total cholesterol, non–high‐density lipoprotein cholesterol, and low‐density lipoprotein cholesterol were positively associated with the presence of carotid IPN in a Chinese high–stroke‐risk population. Further prospective studies should be conducted to better understand how much finding IPN adds to current stroke prediction tools.