ObjectiveTo investigate the value of Vector Flow Imaging (V Flow) in the assessment of post-stenotic turbulence in the canine arterial stenosis model.Materials and MethodsCanine femoral artery stenosis models were established using ameroid constrictors in 12 beagle dogs. 50% and then 70% femoral artery stenoses were confirmed by selective femoral artery angiography. V Flow was used to measure femoral artery flow turbulence index (Tur) preoperatively as a baseline. After establishing of a 50% and then 70% stenoses, the Tur indices were recorded in the femoral artery at 1, 3, 5, 7, 9, 11, 13, 15, 17, and 19 mm distal to the stenosis.ResultsBaseline Tur indices of normal canine femoral arteries were <1% in 11 of 12 cases (91.7%). Distal to a 50% stenosis, the Tur index (>1%) was recorded in 83.3–100% cases between 1 and 9 mm, 41.7–58.3% between 11 and 17 mm, and 16.7% at 19 mm. For a 70% stenosis, the Tur index (>1%) occurred in 81.8–100% cases between 1 and 17 mm distal to the stenosis, and 63.6% at 19 mm. The Tur index peaked around 7 mm or 2.3 times of the initial vessel diameter (3 mm) downstream for a 50% stenosis and 11 mm or 3.7 times of vessel diameter downstream for a 70% stenosis.ConclusionV Flow with Tur index measurement adds quantitative information of post-stenotic turbulence when assessing an arterial stenosis with ultrasound. Tur index of 1% seems a useful threshold for assessment of flow turbulence in this small sample study. Further studies with larger sample size are needed to evaluate the value of V Flow in clinical applications.

Hepatic venous gas (HVG) is a very rare ultrasonic finding, and it is defined as abnormal accumulation of gas in the hepatic venous system. Various diseases can cause HVG, and femoral venous catheter is the most common cause. We, herein, present the case of a 79-year-old female patient with HVG that was caused by spontaneous rupture of a Klebsiella pneumoniae liver abscess. This was first found by bedside ultrasonography. On the basis of the blood culture results, imipenem–cilastatin and cefoperazone sulbactam were administered and the effect was acceptable. After 41 days of antibacterial and symptomatic treatment in the hospital, the patient had recovered well and was discharged. All of the previous reports on HVG have been summarized by thoroughly reviewing the previous published work. Overall, this is the first patient with HVG in association with spontaneous rupture of a K. pneumoniae liver abscess, and it might provide insights for future studies regarding the treatment of this disease.

Background: This study sought to investigate the accuracy of estimating left atrial pressure (LAP) using the continuous wave Doppler spectrum of mitral regurgitation.Methods: Dog models of left atrial hypertension with mitral regurgitation were established with disposable biopsy forceps and the injection of melamine formaldehyde resin microsphere suspension. A total of 40 models of left atrial hypertension with different hemodynamic statuses were established by injecting either esmolol or dobutamine in which the spectrums of mitral regurgitation were clear and the regurgitation velocity exceeded 3.5 m/s. The continuous wave Doppler spectrums of mitral regurgitation were recorded and analyzed to estimate left atrial pressure (LAP ECHO ). The mean left atrial pressure (LAP C-MEAN ), the isovolumic diastolic left atrial pressure (LAP C-IVRT ), the maximum left atrial pressure (LAP C-MAX ), and the minimum left atrial pressure (LAP C-MIN ) were also measured using the catheter method in the same cardiac cycle. Results:The LAP ECHO (mean ± standard deviation; 11.77±4.36 mmHg) was correlated with the LAP C-MEAN (11.51±4.77 mmHg; r=0.887, P=0.000), but the difference was not statistically significant (P=0.459). The LAP ECHO was correlated with the LAP C-IVRT (12.16±4.72 mmHg; r=0.883, P=0.000), but the difference was not statistically significant (P=0.271). There was a correlation between the LAP C-MEAN and the LAP C-IVRT (r=0.987, P=0.000), and the difference was statistically significant (P=0.000).Conclusions: This study suggests that the ultrasound evaluation of LAP correlates well with LAP measured using the gold standard catheter method, and is a simple, convenient, non-invasive method to quantitatively estimate LAP. This method is promising, but further large-scale animal experiments and clinical studies need to be conducted.

Introduction: This study aims to evaluate changes in the arterial spectral Doppler waveform in a canine artery stenosis model. Methods: Canine femoral artery stenosis models were established in 12 beagle dogs. Doppler waveforms were recorded in the femoral artery preoperatively and postoperatively in the femoral artery and at the ankle after formation of a 50%, 70%, and 90% stenosis or occlusion. Major descriptors for arterial Doppler waveform were used to analyse waveforms. Results: The proportion of multiphasic waveforms proximal to a moderate stenosis decreased compared to normal baseline, although the difference was not statistically significant, whereas the decreases at the stenosis, distal to the stenosis, and at the ankle were significant ( p < 0.05). The decreases in arteries with a more severe stenosis or occlusion were significant at all locations ( p < 0.05). The proportion of high resistive waveforms decreased significantly at the ankle in the arteries with a moderate stenosis (50%) ( p = 0.002), but the decreases proximal to, at, and distal to the stenosis were not significant. The decreases were significant at all locations in the arteries with a more severe stenosis ( p < 0.05). The decrease was significant at the ankle in the arteries with an occlusion ( p < 0.001) but not significant pre, at, and post an occlusion. Conclusions: Phasicity and resistance of Doppler waveforms alter in canine femoral arteries with a stenosis. Phasicity change seems more sensitive in response to an arterial stenosis than resistance change. Additional information on arterial resistance could be obtained using end-diastolic ratios, resistive indices, and potentially end-systolic notch velocity measurements.

Background: This study performed an overall assessment of the accuracy of ultrasound-guided fine-needle aspiration (FNA) and core needle biopsy (CNB) for detecting axillary lymph nodes in women with breast cancer based on qualified studies.Methods: Eligible studies and pertinent literature resources were identified on Cochrane, PubMed, Embase, CNKI, VIP, and Wanfang databases through searching key words or terms. The latest study was published in the March 2020. The eligible publications contained cohort and cross-sectional researches. All the publications obtained were tested for heterogeneity, and corresponding effect models were used to calculate amalgamative values of sensitivity, specificity and diagnostic odds ratio (DOR). Analysis of summary receiver operating characteristic (SROC) was performed on suspicious axillary lymph nodes.Results: A total of 22 studies involving 3548 patients were included to explore the accuracy of FNA in identifying axillary lymph nodes in women with breast cancer. 11 studies involving 758 patients were included to explore the accuracy of CNB in identifying axillary lymph nodes in women with breast cancer. The accuracy of FNA in identifying suspicious axillary lymph nodes was specifically as follows: overall sensitivity was 79% (95%CI: 73%-84%), global specificity was 96% (95%CI: 92%-98%), overall positive likelihood ratio was 18.55 (95% CI: 10.53-32.69), overall negative likelihood ratio was 0.22 (95% CI: 0.17-0.28), the overall DOR was 71.68 (95%CI: 37.19-138.12), and the acreage under the SROC was (AUC = 0.94; 95% CI: 0.92-0.96). The accuracy of CNB in identifying suspicious axillary lymph nodes was specifically as follows: overall sensitivity was 85% (95%CI: 81%-89%), global specificity was 93% (95%CI: 87%-96%), overall positive likelihood ratio was 11.88 (95% CI: 6.56-21.50), overall negative likelihood ratio was 0.16 (95% CI: 0.12-0.21), the overall DOR was 66.83 (95%CI: 33.28-134.21), and the acreage under the SROC was (AUC = 0.96; 95% CI: 0.94-0.97).Conclusions: The results indicated that both FNA and CNB had high accuracy for suspicious axillary lymph nodes.