Efficient Microbubble Trajectory Tracking in Ultrasound Localization Microscopy Using a Gated Recurrent Unit-Based Multitasking Temporal Neural Network.

Ultrasound Localization Microscopy (ULM), an emerging medical imaging technique, effectively resolves the classical trade-off between resolution and penetration inherent in traditional ultrasound imaging, opening up new avenues for noninvasive observation of the microvascular system. However, traditional microbubble tracking methods encounter various practical challenges. These methods typically entail multiple processing stages, including intricate steps like pairwise correlation and trajectory optimization, rendering real-time applications unfeasible. Furthermore, existing deep learning-based tracking techniques neglect the temporal aspects of microbubble motion, leading to ineffective modeling of their dynamic behavior. To address these limitations, this study introduces a novel approach called the Gated Recurrent Unit (GRU)-based Multitasking Temporal Neural Network (GRU-MT). GRU-MT is designed to simultaneously handle microbubble trajectory tracking and trajectory optimization tasks. Additionally, we enhance the nonlinear motion model initially proposed by Piepenbrock et al. to better encapsulate the nonlinear motion characteristics of microbubbles, thereby improving trajectory tracking accuracy. In this study, we perform a series of experiments involving network layer substitutions to systematically evaluate the performance of various temporal neural networks, including Recurrent Neural Networks (RNN), Long Short-Term Memory (LSTM), GRU, Transformer, and its bidirectional counterparts, on the microbubble trajectory tracking task. Concurrently, the proposed method undergoes qualitative and quantitative comparisons with traditional microbubble tracking techniques. The experimental results demonstrate that GRU-MT exhibits superior nonlinear modeling capabilities and robustness, both in simulation and in vivo dataset. Additionally, it achieves reduced trajectory tracking errors in shorter time intervals, underscoring its potential for efficient microbubble trajectory tracking. Model code is open-sourced at https://github.com/zyt-Lib/GRU-MT.

Contrast U-Net driven by sufficient texture extraction for carotid plaque detection.

Ischemic heart disease or stroke caused by the rupture or dislodgement of a carotid plaque poses a huge risk to human health. To obtain accurate information on the carotid plaque characteristics of patients and to assist clinicians in the determination and identification of atherosclerotic areas, which is one significant foundation work. Existing work in this field has not deliberately extracted texture information of carotid from the ultrasound images. However, texture information is a very important part of carotid ultrasound images. To make full use of the texture information in carotid ultrasound images, a novel network based on U-Net called Contrast U-Net is designed in this paper. First, the proposed network mainly relies on a contrast block to extract accurate texture information. Moreover, to make the network better learn the texture information of each channel, the squeeze-and-excitation block is introduced to assist in the jump connection from encoding to decoding. Experimental results from intravascular ultrasound image datasets show that the proposed network can achieve superior performance compared with other popular models in carotid plaque detection.

Assessment of left ventricular function in patients with type 2 diabetes mellitus by non-invasive myocardial work.

Background: Diabetes mellitus (DM) is a chronic disease that poses a serious risk of cardiovascular diseases. Therefore, early detection of impaired cardiac function with non-invasive myocardial imaging is critical for improving the prognosis of patients with DM. Purpose: This study aimed to assess the left ventricular (LV) function in patients with type 2 diabetes mellitus (T2DM) by non-invasive myocardial work technique. Materials and methods: In all, 67 patients with T2DM and 28 healthy controls were included and divided into a DM group and a control group. Two-dimensional dynamic images of apical three-chamber view, apical two-chamber view, and apical four-chamber view were collected from all subjects, consisting of at least three cardiac cycles. LV myocardial strain parameters, including global longitudinal strain (GLS) and peak strain dispersion (PSD), as well as myocardial work parameters, including global constructive work (GCW), global wasted work (GWW), global work index (GWI), and global work efficiency (GWE), were obtained and analyzed. Results: A total of 15 subjects were randomly selected to assess intra-observer and inter-observer consistency of myocardial work parameters and strain parameters, which showed excellent results (intra-class correlation coefficients: 0.856 - 0.983, P<0.001). Compared with the control group, the DM group showed significantly higher PSD (37.59 ± 17.18 ms vs. 27.72 ± 13.52 ms, P<0.05) and GWW (63.98 ± 43.63 mmHg% vs. 39.28 ± 25.67 mmHg%, P<0.05), and lower GWE (96.38 ± 2.02% vs. 97.72 ± 0.98%, P<0.001). Furthermore, the PSD was positively correlated with GWW (r = 0.565, P<0.001) and negatively correlated with GWE (r = -0.569, P<0.001). Conclusion: Uncoordinated LV myocardial strain, higher GWW, and lower GWE in patients with T2DM may serve as indicators for the early assessment of cardiac impairment in T2DM.

Body volume is the major determinant of worsening renal function in acutely decompensated heart failure with reduced left ventricular ejection fraction.

AIMS: Little is known about the relative importance of body volume and haemodynamic parameters in the development of worsening of renal function in acutely decompensated heart failure (ADHF). To study the relationship between haemodynamic parameters, body water content and worsening of renal function in patients with heart failure with reduced ejection fraction (HFrEF) hospitalised for ADHF. METHODS AND RESULTS: This prospective observational study involved 51 consecutive patients with HFrEF (age: 73±14 years, male: 60%, left ventricular ejection fraction: 33.3%±9.9%) hospitalised for ADHF. Echocardiographic-determined haemodynamic parameters and body volume determined using a bioelectric impedance analyser were serially obtained. All patients received intravenous furosemide 160 mg/day for 3 days. There was a mean weight loss of 3.95±2.82 kg (p<0.01), and brain natriuretic peptide (BNP) reduced from 1380±901 pg/mL to 797±738 pg/mL (p<0.01). Nonetheless serum creatinine (SCr) increased from 134±46 µmol/L to 151±53 µmol/L (p<0.01), and 35% of patients developed worsening of renal function. The change in SCr was positively correlated with age (r=0.34, p=0.017); and negatively with the ratio of extracellular water to total body water, a parameter of body volume status (r=-0.58, p<0.001); E:E' ratio (r=-0.36, p=0.01); right ventricular systolic pressure (r=-0.40, p=0.009); and BNP (r=-0.40, p=0.004). Counterintuitively, no correlation was observed between SCr and cardiac output, or total peripheral vascular resistance. Regression analysis revealed that normal body volume and lower BNP independently predicted worsening of renal function. CONCLUSIONS: Normal body volume and lower serum BNP on admission were associated with worsening of renal function in patients with HFrEF hospitalised for ADHF.

G6PD inhibits ferroptosis in hepatocellular carcinoma by targeting cytochrome P450 oxidoreductase.

Ferroptosis is an important cell necrosis and has been a focus in cancer related research.Increcsing studies have focused on the phenotype and function of ferroptosis in tumorigenesis, but the underlying mechanism remains poorly understood. Here, we used bioinformatics approaches to identify differentially expressed genes associated with HCC and ferroptosis. We found that G6PD (glucose-6-phosphate dehydrogenase) was highly expressed in HCC and was associated with poor prognosis. G6PD promoted the proliferation, migration and invasion, as well as inhibited ferroptosis in HCC cells. Pathway and functional enrichment analyses revealed that G6PD was related to the P450 metabolic pathway. POR (cytochrome P450 oxidoreductase) was downregulated in HCC and was significantly correlated with the prognosis. G6PD inhibited ferroptosis inin HCC cells through POR. Knockdown of G6PD reduced the tumor volume and tumor weight in vivo. Our study demonstrated that G6PD deficiency suppresses cell growth, metastasis, and tumorigenesis via upregulating POR, suggesting that G6PD may be used as a biomarker for the treatment of HCC in the future.

[Present status and trend of heart fluid mechanics research based on medical image analysis].

With introduction of current main methods for heart fluid mechanics researches, we studied the characteristics and weakness for three primary analysis methods based on magnetic resonance imaging, color Doppler ultrasound and grayscale ultrasound image, respectively. It is pointed out that particle image velocity (PIV), speckle tracking and block match have the same nature, and three algorithms all adopt block correlation. The further analysis shows that, with the development of information technology and sensor, the research for cardiac function and fluid mechanics will focus on energy transfer process of heart fluid, characteristics of Chamber wall related to blood fluid and Fluid-structure interaction in the future heart fluid mechanics fields.

Intuitive visualization and quantification of intraventricular convection in acute ischemic left ventricular failure during early diastole using color Doppler-based echocardiographic vector flow mapping.

The aim of this study was to make an intuitive visualization of intraventricular convection (IC) and quantification of intraventricular convection velocity (ICV) in acute ischemic left ventricular (LV) failure of open-chest canines during early diastole contrast to the baseline conditions using color Doppler-based echocardiographic vector flow mapping (VFM). The animal care committee approved this prospective study. In 6 anesthetized open-chest beagle models, the emergence time and the emergence sites of IC in the LV cavity during early diastole were visualized at the standard apical 3-chamber (AP3c) views with the VFM at baseline conditions and after coronary artery ligation. The global ICV and the ICV at the basal, middle and apical levels of LV at the AP3c views at T1, T2, T3, T4, and T5 between both states were compared respectively (T1: the beginning of LV rapid filling period; T2: the middle of LV rapid filling period; T3: the peak of LV rapid filling period; T4: the middle of period of reduced filling; T5: the end of early diastole.). Acute ischemic LV failure with a marked increase in LV end diastolic volume and LV minimal diastolic pressure was induced by coronary artery ligation. The IC appeared only during the period of reduced filling at baseline conditions, and limited to the basal level of LV cavity. But the IC appeared throughout all the early diastole, and was seen almost occupying whole LV cavity during ischemia. The peak of the global ICV for both states appeared at T4. The global ICV at the AP3c views in acute ischemic failure LV cavity increased than those of baseline conditions at the T1 (6.593 ± 0.834 cm(2)/s vs. 0.000 ± 0.000 cm(2)/s, P < 0.001), T2 (9.457 ± 0.852 cm(2)/s vs. 0.000 ± 0.000 cm(2)/s, P < 0.001), T3 (14.765 ± 1.791 cm(2)/s vs. 2.030 ± 0.502 cm(2)/s, P < 0.001), T4 (25.392 ± 4.640 cm(2)/s vs. 6.688 ± 1.343 cm(2)/s, P < 0.001), and T5 (15.890 ± 3.159 cm(2)/s vs. 2.518 ± 0.869 cm(2)/s, P < 0.001). And the ICV at the basal, middle and apical levels at AP3c views in acute ischemic failure LV cavity also increased than those of baseline conditions at the same phase of early diastole (P < 0.01), except for the ICV at the LV basal level at T1. VFM is a powerful tool for visualization IC and quantification of ICV on profiles of LV flow fields, which can give intriguing insights into the subtle, flow-associated LV fluid dynamics of normal and abnormal cardiac function. It will be of great practical importance to elucidate the accurate physiological and the pathophysiological significance of the IC in further studies, so as to determine whether the cardiac function can be precisely evaluated with IC related index, and to incorporate VFM into clinical routine practice in the future.

[Assessment of carotid plaque rotation angle using ultrasonic imaging].

OBJECTIVE: To demonstrate the abnormal intima rotation pattern of the carotid atherosclerosis plaque using velocity vector imaging, and to develop a new method for the clinical mechanical state assessment of the plaque intima. METHODS: The rotation movement and rotation angle on the serial dynamic ultrasonic short-axis gray scale views of 48 isolated atherosclerosis plaques (i. e., upstream, midstream, and downstream) and nearby reference segments of carotid artery in 46 patients were derived and analyzed using a dedicated velocity vector imaging workstation. The incidence of intima rotation movement and the rotation angle at different sections of the plaque and nearby reference segments before and after the standard grip stress test during systole and diastole respectively were counted and measured. RESULTS: Before and after the stress test, the intima rotation movement occurred at the majority of the short-axis sections of the plaque and the nearby reference segments during cardiac cycle. Before the stress test, the incidence of intima rotation movement at the upstream section of the plaque during systole was significantly higher than that of reference segment (P = 0.036) The reversal direction of the intima rotation at those sections and reference segment during systole and diastole was demonstrated. After the stress test, the incidence of intima rotation movement at the midstream section of the plaque during diastole was significantly lower than that of reference segment (P = 0.031). The incidence of the intima rotation movement changed at the sections of upstream, midstream, and downstream of the plaque before and after the stress test also were explored (i. e., increased in systole and decreased in diastole) except the reference segment intima. CONCLUSIONS: The intima rotation movement occurs at the majority of the isolated plaque and nearby reference segment, and the incidences of the intima rotation movement at the plaque is different from that of the reference segment during systole and diastole respectively. The abnormal pattern of intima rotation movement may be used to indicate the unstable mechanical state of the isolated plaque intima.