High-sensitivity, ultrawide linear range, antibacterial textile pressure sensor based on chitosan/MXene hierarchical architecture.

It is still a great challenge for the flexible piezoresistive pressure sensors to simultaneously achieve wide linearity and high sensitivity. Herein, we propose a high-performance textile pressure sensor based on chitosan (CTS)/MXene fiber. The hierarchical "point to line" architecture enables the pressure sensor with high sensitivity of 1.16 kPa-1 over an ultrawide linear range of 1.5 MPa. Furthermore, the CTS/MXene pressure sensor possesses a low fatigue over 1000 loading/unloading cycles under 1.5 MPa pressure load, attributed to the strong chemical bonding between CTS fiber and MXene and excellent mechanical stability. Besides, the proposed sensor shows good antibacterial effect benefiting from the strong interaction between polycationic structure of CTS/MXene and the predominantly anionic components of bacteria surface. The sensor is also applied to detect real-time human action, an overall classification accuracy of 98.61% based on deep neural network-convolutional neural network (CNN) for six human actions is realized.

Prediction of axillary lymph node metastasis in early breast cancer patients with ultrasonic videos based deep learning.

Objective: To develop a deep learning (DL) model for predicting axillary lymph node (ALN) metastasis using dynamic ultrasound (US) videos in breast cancer patients. Methods: A total of 271 US videos from 271 early breast cancer patients collected from Xiang'an Hospital of Xiamen University andShantou Central Hospitabetween September 2019 and June 2021 were used as the training, validation, and internal testing set (testing set A). Additionally, an independent dataset of 49 US videos from 49 patients with breast cancer, collected from Shanghai 10th Hospital of Tongji University from July 2021 to May 2022, was used as an external testing set (testing set B). All ALN metastases were confirmed using pathological examination. Three different convolutional neural networks (CNNs) with R2 + 1D, TIN, and ResNet-3D architectures were used to build the models. The performance of the US video DL models was compared with that of US static image DL models and axillary US examination performed by ultra-sonographers. The performances of the DL models and ultra-sonographers were evaluated based on accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). Additionally, gradient class activation mapping (Grad-CAM) technology was also used to enhance the interpretability of the models. Results: Among the three US video DL models, TIN showed the best performance, achieving an AUC of 0.914 (95% CI: 0.843-0.985) in predicting ALN metastasis in testing set A. The model achieved an accuracy of 85.25% (52/61), with a sensitivity of 76.19% (16/21) and a specificity of 90.00% (36/40). The AUC of the US video DL model was superior to that of the US static image DL model (0.856, 95% CI: 0.753-0.959, P<0.05). The Grad-CAM technology confirmed the heatmap of the model, which highlighted important subregions of the keyframe for ultra-sonographers' review. Conclusion: A feasible and improved DL model to predict ALN metastasis from breast cancer US video images was developed. The DL model in this study with reliable interpretability would provide an early diagnostic strategy for the appropriate management of axillary in the early breast cancer patients.

Ultrasound Evaluation of Subclavian Artery and Internal Thoracic Artery Before Coronary Artery Bypass Grafting as Part of Preoperative Vascular Assessment.

RATIONALE AND OBJECTIVES: Noninvasive diagnostic imaging of subclavian artery (SCA) and internal thoracic artery (ITA) is crucial to the patients planning to use ITA for coronary artery bypass grafting (CABG). The guidelines have not yet provided guidance on screening high-risk groups. The present study aimed to evaluate the contribution of ultrasonography in the assessment of SCA and ITA, especially for the patients referred for CABG who planned to use ITA graft. MATERIALS AND METHODS: Patients diagnosed with multivessel coronary heart disease were enrolled and some of them planned CABG. Bilateral SCAs and ITAs were routinely evaluated by color Doppler ultrasound (CDUS) before operation. The luminal diameter and the peak systolic velocity of the proximal and distal parts of SCA and ITA were measured. Depending on the Doppler waveform, the lumen narrowing rate was calculated. RESULTS: The final analysis was carried out in 572 patients. Thirty-five patients had moderate (50%-69%), severe (70%-99%) stenosis or occlusion in the SCA (left-sided in 21 and right-sided in 14). One patient had severe proximal stenosis in left ITA and one patient had no flow in left ITA due to the occlusion in left SCA. One patient had anatomic variation of isolated right aortic arch with aberrant left SCA. All of those cases were confirmed with multidetector computed tomography angiography. CONCLUSION: CDUS could be used for the evaluation of SCA and ITA before CABG as part of presurgical vascular assessment and provide an import basis for the imaging diagnosis and surgical plan.

Assessment of ultrasound shear wave elastography within muscles using different region of interest sizes, manufacturers, probes and acquisition angles: an ex vivo study.

Background: The application of shear wave elastography (SWE) in assessment of the musculoskeletal system is affected by various factors. This study aimed to explore the influence of machines, probes, region of interest (ROI) sizes, and the acquisition angles on muscle shear wave speed (SWS). Methods: The SWS of ex vivo isolated muscles were acquired using 3 different machines (Aixplorer system, SuperSonic Imagine; Acuson S3000, Siemens Healthcare; Resona 7, Mindray) and 2 linear probes (Aixplorer system, SL 10-2 and SL 15-4). Also, 4 different ROI sizes (diameter 1-10 mm) and 9 different acquisition angles (0-40°) were tested. The SWS acquired under different conditions were compared, and the intra-class correlation coefficients (ICC) were used to evaluate reproducibility. Results: There was a significant difference in SWS acquired using the 3 different machines (P<0.001) or with 9 different angles (P=0.008). There was no significant difference in SWS acquired using 2 probes (P=0.053) or 4 different ROI sizes (P=0.874, 0.778, and 0.865 for 3 operators, respectively). All machines produced substantial intra-system reproducibility (ICC, 0.61-0.80). Both probes demonstrated an almost perfect degree of intra-system agreement (ICC, >0.80), and nearly all ROI sizes demonstrated an almost perfect degree of intra- and inter-operator agreement (ICC, >0.80). The measurement reliability was higher when the acquisition angles were no more than 20°. Conclusions: The 3 machines had different SWS values. Attention should be paid when comparing SWS results using different machines. For the Aixplorer system, the ROI size had no effect on the SWS values. Angles larger than 25° will lead to SWS measurements with greater variability compared to smaller angles (≤20°).

The Role of Color Doppler Ultrasonography in the Perioperative Period of Coronary Artery Bypass Grafting: Comparison with Transit-Time Flow Measurement.

INTRODUCTION: The value of color Doppler ultrasonography (CDUS) with the supraclavicular approach for preoperative evaluation of the native left internal mammary artery (LIMA) as well as for the postoperative detection of LIMA graft patency was recently suggested. However, the parameters such as the flow volume and pulsatile index (PI) have not been studied in detail. OBJECTIVES: The objectives of this study were to analyze the LIMA data in the perioperative period and explore the relationships between the intraoperative graft flow with transit-time flow measurement (TTFM) and the postoperatively measured parameters with CDUS. METHODS: Fifty-eight patients with significant stenosis (≥70%) or occlusions in left anterior descending artery (LAD) who were referred for isolated coronary artery bypass grafting (CABG) were enrolled in this study and examined by CDUS prior to CABG from April to July 2016. The perioperative measurements of proximal LIMA by CDUS were compared. In addition, the correlation between the intraoperative graft flow, such as the mean graft flow (MGF) and PI, and the immediate postoperative measurements of CDUS in LIMA bypassed grafts was statistically analyzed. RESULTS: Six patients were excluded due to screening failure, or insufficient visualization of CDUS images for analysis. Fifty-two patients with in situ LIMA-LAD graft, with or without additional arterial grafts or saphenous vein grafts, were included in the final analysis. The postoperative diameters of proximal LIMA were not significantly different from preoperative diameters (2.21 ± 0.18 vs. 2.27 ± 0.22 mm, p = 0.070). The flow volume on the early postoperative CDUS significantly increased (39.77 ± 21.59 vs. 25.96 ± 13.17 mL/min, p < 0.001) and the PI significantly decreased (1.43 ± 0.46 vs. 4.20 ± 1.49, p < 0.001) versus those of preoperative measurements. The MGF had a moderate correlation with the flow volume on the early postoperative CDUS (r = 0.414, p = 0.002), and the PI by TTFM had a weak correlation with that by CDUS (r = 0.353, p = 0.010) as well. CONCLUSIONS: The MGF and PI by TTFM in CABG were associated with in situ LIMA graft parameters measured by CDUS studies. CDUS is a useful functional noninvasive tool for the preoperative screening and postoperative follow-up of patients with in situ LIMA bypass.

Primary external iliac vein leiomyosarcoma in a young female diagnosed by contrast-enhanced ultrasound: A case report.

RATIONALE: Venous leiomyosarcoma (LMS) is a malignant tumor arising from the smooth muscle cell of the vein wall. The diagnosis of venous LMS is usually delayed owing to its rarity, absence of serological markers, and mimicry with deep vein thrombosis (DVT). Herein, we report a case of a primary external ilian vein LMS characterized by long-term, unexplained DVT in the left lower limb. Contrast-enhanced ultrasound (CEUS) played a crucial role in the preoperative diagnosis. No improvement was observed in the lower limb status; a rapid, high-level, heterogeneous wash-in and wash-out mass of the vein, as seen with CEUS, could indicate angiogenic malignancy. CEUS also helped evaluate the percent of intratumoral necrosis, which is an important parameter for predicting the prognosis. PATIENT CONCERNS: A 37-year-old Chinese women presented to the Vascular Surgery Department of our hospital for accurate diagnosis of her condition. She began experiencing edema and pain in her left leg 2 years ago. She was diagnosed with DVT in the left lower extremity and was administered anticoagulant therapy since then. However, her symptoms started to aggravate 8 months ago. DIAGNOSES: The laboratory results including D-dimer, prothrombin time (PT), activated partial thrombin time (APTT), and prothrombotic conditions screening were within normal ranges. A pelvic ultrasound detected a heterogeneous, hypoechoic mass compressing the external iliac vein and obstructing the venous drain of the lower extremity. The mass showed a rapid, high-level, heterogeneous wash-in and wash-out on CEUS, which suggested angiogenic malignancy. Contrast-enhanced CT (CECT) confirmed the result of CEUS but revealed no metastasis. INTERVENTIONS: She underwent complete surgical removal of the tumor, which was resected successfully. There was no infiltration in the inguinal nodes sent for the study. OUTCOMES: Pathological examination and immunohistochemistry confirmed that the mass was a well-differentiated LMS originating from the external iliac vein. There was no sign of local recurrence or distant metastasis during a 12-month follow-up. LESSONS: Effective imaging techniques and differential diagnosis of venous LMS is vital and should be considered for patients with chronic thrombosis presenting with normal laboratory results.

Effect of acquisition depth and precompression from probe and couplant on shear wave elastography in soft tissue: an in vitro and in vivo study.

BACKGROUND: Shear wave elastography is a promising method to diagnose early musculoskeletal lesions. We aimed to explore the feasible depth and acceptable precompression applied by probe and couplant for soft tissues in the present system. METHODS: Ex-vivo muscles were evaluated at depths of 0.5-6 cm by 3 operators, using 1-5 mm couplant thickness and 0-3.0 kPa probe pressure. We compared the shear wave speed (SWS) and used intraclass correlation coefficients to assess reproducibility. In vivo skin and subcutaneous superficial fascia from volunteers were tested at depths ranging from 0.1-0.5 cm with 1-20 mm couplant thickness. RESULTS: The SWS of ex-vivo muscles varied and increased with depth, and could not be acquired at 6 cm because the shear wave failed to be detected. Furthermore, while the SWS of ex-vivo muscles were not affected by the couplant thickness, it was affected by probe pressure. Most cases demonstrated a satisfactory agreement degree of the intraoperator reproducibility (ICC, 0.81-0.95) and a substantial interoperator reproducibility (ICC >0.60). Inter- and intra-operator reproducibility was better at a depth of 0.5-4 cm than at 5 cm. In the in vivo study, when tissues within a 0.2 cm depth were evaluated, the SWS that was acquired using a couplant thickness of >10 mm was different from that acquired using other thicknesses. CONCLUSIONS: The SWS acquired at a depth of ≤3 cm with a suitable amount of couplant is recommended.

Prenatal ultrasonic diagnosis and differential diagnosis of isolated right aortic arch with mirror-image branching.

PURPOSE: This study sought to evaluate the fetal echocardiography features of isolated right aortic arch (RAA) with mirror-image branching and to improve the rate and accuracy of prenatal diagnosis of this condition. METHODS: We reviewed fetal echocardiograms from all cases of isolated RAA with mirror-image branching diagnosed at our institution between August 2012 and December 2015 and classified these cases into normal and abnormal types of ductus arteriosus based on the course of the arterial duct arch. We confirmed the diagnoses by postnatal echocardiography. RESULTS: A total of 11 cases of isolated RAA with mirror-image branching, with the left ductus and the descending aorta located on the left side of the spine, were diagnosed using fetal echocardiography. Ten cases involved normal ductus arteriosus, with the left ductus connecting the left pulmonary artery to the descending aorta, five of which were referred to our institution for suspicions of double aortic aorta. 1 case involved abnormal ductus arteriosus, with the left ductus connecting the left pulmonary artery to the left innominate artery. CONCLUSIONS: RAA with mirror-image branching can be detected via fetal echocardiography, which can reveal the relationship between of the aortic arch and the trachea and can enable the identification of the course of brachiocephalic branching. The identification of isolated RAA with mirror-image branching is crucial for distinguishing this condition from other types of aortic arch anomalies, particularly double aortic aorta, which can have a rather different prognosis.

Continuous transverse scanning of the fetal heart using a cross-sectional image database of common fetal congenital heart deformities.

OBJECTIVE: To provide an anatomical basis for continuous transverse scanning of the fetal heart by analyzing the typical cross-sectional characteristics of different types of congenital heart deformities (CHDs) using an anatomical image database. MATERIALS AND METHODS: The database consisted of cross-sectional images obtained from 45 cases of common fetal CHDs, which were continuously displayed by the three-dimensional software Amira 5.3.1. The following anatomical parts were observed from the database of heart samples in a bottom-to-top manner: the coronary sinus, four chambers, left ventricular outflow tract, right ventricular outflow tract, and transverse ductal and aortic arches. The anatomical characteristics of these sections were analyzed and compared with the ultrasonic transverse views obtained from the same fetuses. RESULTS: During the display of the anatomical database of 45 cases of common fetal CHDs, the aforementioned typical cross sections were successively revealed, along with the corresponding pathological features. These sections also exhibited a very good correspondence with the ultrasonic transverse views of the same cases. CONCLUSION: The database of cross-sectional anatomical images of fetal CHDs provided an anatomical basis for continuous transverse scanning of the fetal heart.

Establishment of a database of fetal congenital heart malformations and preliminary investigation of its clinical application.

OBJECTIVE: The aim of this study was to create a database of anatomical ultrathin cross-sectional images of fetal hearts with different congenital heart diseases (CHDs) and preliminarily to investigate its clinical application. MATERIALS AND METHODS: Forty Chinese fetal heart samples from induced labor due to different CHDs were cut transversely at 60-µm thickness. All thoracic organs were removed from the thoracic cavity after formalin fixation, embedded in optimum cutting temperature compound, and then frozen at -25°C for 2 hours. Subsequently, macro shots of the frozen serial sections were obtained using a digital camera in order to build a database of anatomical ultrathin cross-sectional images. RESULTS: Images in the database clearly displayed the fetal heart structures. After importing the images into three-dimensional software, the following functions could be realized: (1) based on the original database of transverse sections, databases of sagittal and coronal sections could be constructed; and (2) the original and constructed databases could be displayed continuously and dynamically, and rotated in arbitrary angles. They could also be displayed synchronically. The aforementioned functions of the database allowed for the retrieval of images and three-dimensional anatomy characteristics of the different fetal CHDs, and virtualization of fetal echocardiography findings. CONCLUSION: A database of 40 different cross-sectional fetal CHDs was established. An extensive database library of fetal CHDs, from which sonographers and students can study the anatomical features of fetal CHDs and virtualize fetal echocardiography findings via either centralized training or distance education, can be established in the future by accumulating further cases.