Ultrasound Blood Flow Signals Research Articles

Effect, sensitivity, specificity and accuracy of ultrasonic assessment of axillary lymph node-negative breast cancer.

To investigate the diagnostic value of ultrasound for patients with axillary lymph node-negative breast cancer (ALNNBC). A retrospective analysis was performed on the clinical data of 204 breast cancer patients who were admitted by Quanzhou First Hospital Affiliated to Fujian Medical University between October 2020 and May 2022. According to the results of axillary lymph node (ALN) examination, the patients were assigned to a positive group(n=102) and a negative group(n=102). All patients underwent diagnosis with color Doppler ultrasound, with pathological diagnosis as the "gold standard" to determine the sensitivity and specificity of ultrasonic diagnosis. A receiver operating characteristic(ROC) curve was established to analyze the efficiency of ultrasonic diagnosis and compare the ultrasonographic features and flow grades between the two groups. Differences were statistically significant between the two groups in ultrasonographic features of lesions(negative vs positive, all p<0.05), including morphological irregularity(59.8% vs 85.3%), spiky margins(19.6% vs 63.7%), posterior echo attenuation(19.6% vs 44.1%) and microcalcification(40.2% vs 55.89%). The negative group had a lower proportion of patients with grade 2-3 ultrasound blood flow when compared with the positive group(32.4% vs 56.86%), and the difference was statistically significant(p<0.05). Ultrasonic diagnosis of ALNNBC had a sensitivity of 88.24%(90/102), a specificity of 92.16%(94/102), a coincidence rate of 90.20% (184/204), a 95% CI of 0.845-0.928, and an AUC of 0.879. Ultrasonic diagnosis of ALNNBC is relatively efficient as ultrasonographic features and ultrasound blood flow signals can provide a scientific basis for the diagnosis of ALNNBC.

The diagnostic value of ultrasound in pediatric testicular torsion with preserved flow.

BackgroundTesticular torsion is the reduction of blood flow to the testis after spermatic cord torsion. For patients, the diagnosis of testicular torsion is controversial and complicated by the fact that ultrasound blood flow signals are not significantly reduced in comparison to the unaffected, healthy, testis, despite persistent symptoms on the affected side. Our study aims to investigate the diagnostic characteristics of high-resolution ultrasonography (US) in pediatric testicular torsion with the preserved flow to increase diagnostic accuracy.MethodsSeven pediatric patients aged 49 days to 15 years old, with the preserved blood flow, but surgically diagnosed as testicular torsion, from October 2017 to August 2019, were retrospectively included in the study. The imaging manifestations of high-frequency ultrasonography were evaluated.ResultsAll cases had preserved testicular blood flow, but the surgical findings showed various degrees of twist, from 90 to 540 degrees. Preoperative ultrasound showed spermatic cord distortion in all cases, and testicular long axis tilting in four cases (4/7 = 57.1%).ConclusionIn some testicular torsion cases, Color Doppler may show normal or increased blood flow signals in the testis. We should further observe the morphology and position of the testes and epididymides, the echo of the testicular parenchyma, and, especially evaluate the “whirlpool sign” in the spermatic cord, to avoid missing testicular torsion with blood flow signals.

Windkessel Model-Based Cuffless Blood Pressure Estimation Using Continuous Wave Doppler Ultrasound System

Blood pressure (BP) measurement plays an essential role in the prevention of cardiovascular diseases. Studies have demonstrated Ultrasound (US) based BP analysis method combining with peripheral components of the circulatory system. In this paper, a cuffless BP measurement technique has been proposed using a portable continuous wave Doppler US system which consumes < 4 Watt of power. The US blood flow signal acquired utilizing 8 MHz pencil transducer probe from the brachial artery is denoised using soft thresholding method. The spectrogram envelope of maximum frequency is obtained by an adaptive signal noise slope intersection (SNSI) method to extract hemodynamic features. In the proposed method, 2-element Windkessel (WK) model consisting of peripheral resistance and arterial compliance is employed for BP estimation. Based on the extracted features, a machine learning algorithm determines the WK model parameters. From the experiments conducted on 85 subjects, it has been observed that both systolic and diastolic BP achieve Grade B and Grade C for British Hypertension Society (BHS) and IEEE Std. 1708 protocols, respectively. Regarding Association for the Advancement of Medical Instrumentation (AAMI) standard, diastolic BP estimation error is within an acceptable limit. The robustness of the approach is examined using pre-exercise and post-exercise performance of 10 subjects. Moreover, the effect on arterial compliance for increased BP and aging is observed to characterize the dynamic property of arterial system. The proposed method is non-invasive, non-occlusive, independent of any additional interfaces, operates with a small dataset and worthy of implementation as a portable system for point-of-care application.