Measurement of arterial occlusion pressure using straight and curved blood flow restriction cuffs.

Arterial occlusion pressure (AOP) is influenced by the characteristics of the cuff used to measure AOP. Doppler ultrasound was used to measure AOP of the brachial and superficial femoral arteries using straight and curved blood flow restriction cuffs in 21 males and 21 females. Vessel diameter and blood flow were evaluated as independent predictors of AOP. Overall, there were no significant differences in AOP when using the straight and curved cuffs in the brachial (129 mmHg vs. 128 mmHg) or superficial femoral artery (202 mmHg vs. 200 mmHg), respectively. Overall, AOP was greater (p < 0.05) in males than in females in the arm (135 mmHg, 123 mmHg) and leg (211 mmHg, 191 mmHg). Brachial (0.376 mm, 0.323 mm) and superficial femoral (0.547 mm, 0.486 mm) arteries were larger (p = 0.016) in males than in females, respectively. Systolic blood pressure (SBP) and arm circumference were predictive of brachial artery AOP, whereas SBP, diastolic blood pressure, thigh circumference, and vessel diameter were predictive of superficial femoral artery AOP. Straight and curved cuffs are efficacious in the measurement of AOP in the arm and leg. Differences in vessel size may contribute to sex differences in AOP but this requires further investigation.

Doppler-Derived Renal Functional Reserve in the Prediction of Postoperative Acute Kidney Injury in Patients Undergoing Robotic Surgery.

BACKGROUND: Postoperative acute kidney injury (PO-AKI) is a frequent complication after surgery. Various tools have been proposed to identify patients at high risk for AKI, including preoperative serum creatinine or estimated glomerular filtration rate (eGFR), urinary cell cycle arrest, and tubular damage biomarkers; however, none of these can appropriately assess AKI risk before surgery. Renal functional reserve (RFR) screened by the Doppler-derived intraparenchymal renal resistive index variation (IRRIV) test has been proposed to identify patients at risk for AKI before a kidney insult. IRRIV test has been developed in healthy individuals and previously investigated in cardiac surgery patients. This study aims to evaluate the value of the IRRIV test in identifying PO-AKI among patients undergoing robotic abdominal surgery in the Trendelenburg position for pelvic oncological disease. METHODS: We performed a prospective, double-blinded, observational study. Preoperative baseline renal function and RFR were assessed in 53 patients with baseline eGFR >60 mL/min/1.73 m2, undergoing robotic surgery in the Trendelenburg position for pelvic oncological disease. The capability of Doppler-derived RFR in predicting PO-AKI was investigated with the area under the receiver operating characteristic curve (ROC-AUC). RESULTS: Approximately 15.1% of patients developed AKI within the first 3 postoperative days. Thirty-one (58.5%) patients had a physiologic delta-RRI (ie, ≥0.05), while 22 (41.5%) patients did not. The ROC-AUC for PO-AKI was 0.85 (95% confidence interval [CI], 0.74-0.97; P = .007) for serum creatinine, 0.84 (95% CI, 0.71-0.96; P = .006) for eGFR, and 0.84 (95% CI, 0.78-0.91; P = .017) for delta-RRI. When combined with eGFR, the ROC-AUC for delta-RRI was 0.95 (95% CI, 0.9-1). CONCLUSIONS: Our findings show that the preoperative assessment of Doppler-derived RFR combined with baseline renal function improves the capability of identifying patients at high risk for PO-AKI with eGFR >60 mL/min/1.73 m2 after robotic abdominal surgery in Trendelenburg position for pelvic oncological disease.

Effects of the Cold Pressor Test on Popliteal Vein Diameter, Flow Velocity, and Blood Flow in the Lower Limb in 60 Healthy Individuals.

BACKGROUND In various situations such as pain, exposure to hot or cold, and mental stress, where physiological stress occurs, the increased excitatory response in the sympathetic efferent neurons leads to an increased return of blood flow from the peripheral veins to the right atrium. The cold pressor test (CPT) is based on the effects of a cold stimulus that activates afferent sensory pathways to trigger a sympathetic response, resulting in an increase in blood pressure. This study aimed to evaluate the effects of the cold pressor test on popliteal vein diameter, flow velocity, and blood flow in the lower limbs in 60 healthy individuals. MATERIAL AND METHODS We included 30 men and 30 women age 18-40 years. Baseline vein diameter, flow velocity, and blood flow of the left popliteal vein were measured by Doppler ultrasound, then the left hand was immersed in a bucket of cold water. After immersing the hand in cold water for 1 minute (CPT-1), 3 measurements of vein diameter, flow velocity, and blood flow were taken again, and their averages were calculated. RESULTS In the study, data obtained from the individuals were statistically analyzed. At CPT-1, venous diameter and flow values showed significant increase compared to baseline (P=0.001, P<0.001, respectively). CONCLUSIONS In healthy volunteers, CPT increases venous flow in the popliteal veins. However, our study did not provide evidence for the hypothesis that the increase in venous return is due to venoconstriction mechanisms.

Investigation of the relationship between diastolic notching in uterine artery Doppler and serum salusin alpha and beta concentrations in the first trimester.

OBJECTIVE: Studies have shown that members of the salusin family regulate the migration and proliferation of arterial smooth muscle cells and increase the tendency to atherosclerosis through fibrosis and calcification in the vascular wall. However, the effect of salusins on the uterine artery has not yet been investigated. This study was conducted to investigate whether serum salusin alpha and beta concentrations in the first trimester are associated with diastolic notching in uterine artery Doppler. METHODS: This non-interventional cohort study was conducted on 88 pregnant women, 44 of whom had diastolic notching on unilateral or bilateral uterine artery Doppler, and 44 of whom did not have diastolic notching on uterine artery Doppler. The uterine artery notch positive and negative groups were compared in terms of serum salusin alpha and beta concentrations. RESULTS: The two groups were similar in terms of demographic characteristics (p < 0.05). The median salusin alpha concentration was found to be 689.4 pg/ml in the uterine artery notch positive group, while it was 734.6 pg/ml in the uterine artery notch negative group (p = 0.608). The median salusin beta concentration was found to be 674.5 pg/ml in the uterine artery notch positive group, while it was 693.8 pg/ml in the uterine artery notch negative group (p = 0.453).Participants were regrouped into normal and high uterine artery resistance and compared in terms of serum salusin alpha and beta concentrations. The median salusin alpha concentration was found to be 994.5 pg/ml in the high uterine artery PI group, while it was 685.2 pg/ml in the normal uterine artery PI group (p = 0.698). The median salusin beta concentration was found to be 1,100.8 pg/ml in the high uterine artery PI group, while it was 669.1 pg/ml in the normal uterine artery PI group (p = 0.584). CONCLUSION: Although the sample size was too small to draw a definitive conclusion, our results indicate that uterine artery diastolic notching or increased resistance in the uterine artery does not appear to be associated with serum salusin alpha or beta concentrations.

The effect of endoscopic renal and ureteral stone surgeries on renal blood flow in children: a prospective trial.

AIM: To assess the impact of endoscopic stone surgeries on renal perfusion and blood flow in children. MATERIALS AND METHODS: Children who underwent percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), ureterorenoscopy (URS), endoscopic combined intrarenal surgery (ECIRS) were included to the study. Renal Doppler ultrasonography (RDUS) was performed one day before the operation, and on the postoperative 1st day and 1st month. Peak systolic velocity (PSV) and end-diastolic velocity (EDV) were measured, and resistive index (RI) was calculated with the (PSV-EDV)/PSV formula. RDUS parameters were compared before and after surgery and between ipsilateral and contralateral kidneys. RESULTS: A total of 45 children with a median age was 8 (2-17) years were included (15 (33.3%) girls, 30 (66.7%) boys). PCNL was performed in 13 children (28.9%), RIRS 11 (24.4%), URS 12 (26.7%), and ECIRS 9 (20%). There was no significant difference in renal and segmental PSV, EDV and RI values of operated kidney in the preoperative, postoperative periods. There was no significant difference between RDUS parameters of the ipsilateral and contralateral kidneys in preoperative or postoperative periods. PSV and EDV values were significantly higher in the 1st postoperative month in the group without preoperative DJ stent than in the group with DJ stent (p = 0,031, p = 0,041, respectively). However, RI values were similar. The mean RI were below the threshold value of 0.7 in each period. CONCLUSION: RDUS parameters didn't show a significant difference in children. Endoscopic surgeries can be safely performed in pediatric stone disease.

Management of Suspected Peripheral Vascular Injuries in Orthopedic Trauma.

OBJECTIVE: In orthopedic trauma, identification of extremity trauma combined with vascular injury is challenging. Missed diagnosis may result in amputation or even death. The purpose of this study was to investigate whether physical examination combined with handheld vascular ultrasound Doppler examination could be an effective method of screening for peripheral vascular injury and to explore the characteristics of vascular injuries in orthopedic trauma patients. METHODS: Retrospective analysis of patients in the emergency department of orthopedic trauma in our hospital from January 2022 to October 2023. Physical examination combined with handheld vascular ultrasound Doppler examination was used as a screening method for suspected vascular injuries. Patients with suspected vascular injury would undergo further angiography and receive multidisciplinary treatment. Angiography was used as the gold standard for diagnosing vascular injuries. Patient demographics, mechanism of injury, location and type of injury, angiographic results, surgical notes, and early treatment outcome data were recorded. RESULTS: A total of 55 cases (58 limb injuries) with suspected vascular injury were ultimately included. Angiography revealed that 53 cases (55 limbs, positive rate 94.8%) were considered to have confirmed vascular injuries. Forty-three were male (81.1%) and 10 were female (18.9%), with mean age 44.1 ± 16.6 years. The main mechanism of injury was traffic accident (30, 56.7%). Most common site of vascular injuries was knee joint (30/55, 54.5%), and popliteal artery (23, 47.9%) was the most commonly injured blood vessel. After multidisciplinary collaborative treatment, overall patient mortality was 3.8% (2/53), and limb survival rate among surviving patients was 81.1% (43/53) in our study. CONCLUSION: In orthopedic trauma, "Hard signs" and "soft signs" combined with handheld vascular ultrasound Doppler examination were effective ways to screen for suspected vascular injuries. Most limbs had associated fractures or dislocations at the site of vascular injury. Collaboration of vascular surgery, microsurgery and orthopedic trauma may help improve patients' prognosis.

Predictive value of ultrasound doppler parameters in neoadjuvant chemotherapy response of breast cancer: Prospective comparison with magnetic resonance and mammography.

BACKGROUND: Neoadjuvant chemotherapy (NACT) is a treatment option for breast cancer patients that allows for the assessment of tumor response during treatment. This information can be used to adjust treatment and improve outcomes. However, the optimal imaging modalities and parameters for assessing tumor response to NACT are not well established. METHODS: This study included 173 breast cancer patients who underwent NACT. Patients were imaged with ultrasound (US), mammography (MMG), and magnetic resonance imaging (MRI) at baseline, after two cycles of NACT, and before breast surgery. US parameters included lesion morphology, Doppler variables, and elastography measurements. MMG and MRI were evaluated for the presence of nodules and tumor dimensions. The pathological response to NACT was determined using the residual cancer burden (RCB) classification. RESULTS: The US parameter with the highest power for predicting pathological complete response (pCR) was shear wave elastography (SWE) maximum speed inside the tumor at baseline. For nonluminal tumors, the end diastolic velocity measured by US after two cycles of NACT showed the highest predictive value for pCR. Similarly, SWE maximum speed after two cycles of NACT had the highest discriminating power for predicting RCB-III in luminal tumors, while the same parameter measured at baseline was most predictive for nonluminal tumors. CONCLUSIONS: This study provides evidence that mid-treatment Doppler US and other imaging modalities can be used to predict the response to NACT in breast cancer patients. Functional parameters, such as blood flow velocities and SWE measurements, demonstrated superior predictive value for pCR, while morphological parameters had limited value. These findings have implications for personalized treatment strategies and may contribute to improved outcomes in the management of breast cancer.

Assessment of quantitative microflow Vascular Index in testicular cancer.

PURPOSE: Ultrasound (US) is the primary imaging modality when a testicular tumor is suspected. Superb microvascular imaging (SMI) is a novel, highly sensitive Doppler technique that allows quantification of flow signals by determination of the Vascular Index (VI). The aim of the present study is to investigate the diagnostic significance of the SMI-derived VI in normal testicular tissue and testicular cancer. METHODS: This retrospective analysis included patients who underwent testicular US in our department from 2018 to 2022. Inclusion criteria were: i) sufficient image quality of the stored images, ii) US with standardized SMI-default setting (colour gain of 44 ± 5), iii) patient age ≥ 18 years, and iv) normal testicular findings or testicular tumor with histopathological workup. US examinations were performed as part of clinical routine using a high-end ultrasound system (Aplio i800/i900, Canon Medical Systems Corporation, Tochigi, Japan). Statistical analysis included Chi-square test and Mann-Whitney U tests and receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 62 patients (31 each with normal findings and testicular tumors) were included. The VI differed statistically significantly (p < 0.001) between normal testis (median 2.5 %) and testicular tumors (median 17.4 %). Like vascular patterns (p < 0.001), the VI (p = 0.030) was shown to distinguish seminomas (median 14.8 %), non-seminomas (median 17.6 %) and lymphomas (median 34.5 %). CONCLUSIONS: In conclusion, our study has shown the VI to be a quantitative tool that can add information for differentiating testicular tumor entities. While further confirmation in larger study populations is desirable, our results suggest that the VI may be a useful quantitative parameter.

Subclinical joint inflammation in rheumatoid arthritis: comparing thermal and ultrasound imaging at the metacarpophalangeal joint.

BACKGROUND: While ultrasound and MRI are both superior to clinical examination in the detection of joint inflammation, there is presently a lack of data whether thermography may be similarly useful in the assessment of joint inflammation in patients with RA. Our study aims to evaluate the use of thermography in detecting subclinical joint inflammation at clinically quiescent (non-tender and non-swollen) metacarpophalangeal joints (MCPJs) in patients with rheumatoid arthritis (RA). The outcomes from thermography in our study will be compared with ultrasonography (which is a more established imaging tool used for joint inflammation assessment in RA). METHODS: The minimum (Tmin), average (Tavg) and maximum (Tmax) temperatures at the 10 MCPJs of each patient were summed to obtain the Total Tmin, Total Tavg and Total Tmax, respectively. Ultrasound grey-scale (GS) and power Doppler (PD) joint inflammation (scored semi-quantitatively, 0-3) at the 10 MCPJs were summed up to derive the respective TGS and TPD scores per patient. Pearson's correlation and simple linear regression were respectively used to assess correlation and characterize relationships between thermographic parameters (Total Tmin, Total Tavg and Total Tmax) and ultrasound imaging parameters (TGS, TPD and the number of joint(s) with PD ≥ 1 or GS ≥ 2). RESULTS: In this cross-sectional study, 420 clinically non-swollen and non-tender MCPJs from 42 RA patients were examined. All thermographic parameters (Total Tmin, Total Tavg and Total Tmax) correlated significantly (P-values ranging from 0.001 to 0.0012) with TGS score (correlation coefficient ranging from 0.421 to 0.430), TPD score (correlation coefficient ranging from 0.383 to 0.424), and the number of joint(s) with PD ≥ 1 or GS ≥ 2 (correlation coefficient ranging from 0.447 to 0.465). Similarly, simple linear regression demonstrated a statistically significant relationship (P-values ranging from 0.001 to 0.005) between all thermographic parameters (Total Tmin, Total Tavg and Total Tmax) and ultrasound imaging parameters (TPD and TGS). CONCLUSION: For the first time, thermographic temperatures were shown to correlate with ultrasound-detected joint inflammation at clinically quiescent MCPJs. The use of thermography in the detection of subclinical joint inflammation in RA appears promising and warrants further investigation.

Utility of uterine artery Doppler ultrasound imaging in predicting preeclampsia during pregnancy: a meta-analysis.

AIMS: Accurate prediction of preeclampsia could improve maternal outcomes. However, the role of uterine artery Doppler ultrasound in predicting preeclampsia remains unclear. MATERIALS AND METHODS: We comprehensively searched several electronic databases, including PubMed, EMBASE, the Cochrane Library, and Web of Science, covering studies published from the time of database creation to September 23, 2023. Studies on the predictive value of uterine artery Doppler ultrasound for preeclampsia were included. The primary pregnancy outcome was preeclampsia. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 scoring scale. RESULTS: The use of resistance index (RI) for predicting preeclampsia demonstrated the highest sensitivity of 0.73 (95% confidence interval [CI], 0.30-0.94) and specificity of 0.90 (95% CI, 0.72-0.97), with a pooled area under the curve value of 0.91 (95% CI, 0.88-0.93). The use of pulsatility index (PI) for predicting preeclampsia showed a sensitivity of 0.65 (95% CI, 0.45-0.81) and specificity of 0.88 (95% CI, 0.77-0.94). Furthermore, preeclampsia prediction via notching showed a sensitivity of 0.54 (95% CI, 0.38-0.68) and specificity of 0.89 (95% CI, 0.79-0.95). CONCLUSIONS: These findings highlight the varying predictive performance of different preeclampsia indices. PI and RI demonstrated moderate-to-high sensitivity and specificity, whereas notching exhibited relatively lower sensitivity but comparable specificity. Further research and validation are warranted to consolidate these results and enhance the accuracy of preeclampsia prediction.

[Dynamic functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]. / Dinamicheskaya funktsional'naya otsenka patologicheskikh izvitostei vnutrennikh sonnykh arterii u bol'nykh s mul'tifokal'nym aterosklerozom. Klinicheskii sluchai.

A personalized approach with attention to anamnesis and specific symptoms is necessary in patients with internal carotid artery tortuosity. Neuroimaging (especially before elective surgery) or functional stress tests following ultrasound of supra-aortic vessels may be necessary depending on medical history and complaints. In addition to standard Doppler ultrasound, these patients should undergo rotational and orthostatic transformation tests. We analyze changes in shape and hemodynamic parameters within the tortuosity area in various body positions. This is especially valuable for patients with concomitant carotid artery stenosis. The article presents a clinical case illustrating the importance of such approach.

[Functional assessment of internal carotid artery tortuosity in patients with multifocal atherosclerosis]. / Vazhnost' dinamicheskoi funktsional'noi otsenki patologicheskoi izvitosti vnutrennikh sonnykh arterii u bol'nykh s mul'tifokal'nym aterosklerozom.

The review is devoted to diagnosis and treatment of internal carotid artery tortuosity. The authors consider modern classification, epidemiology and diagnostic options using neuroimaging or ultrasound-assisted functional stress tests depending on medical history and complaints. In addition to standard Doppler ultrasound, rotational and orthostatic tests are advisable due to possible changes of local shape and hemodynamic parameters following body position changes, especially in patients with concomitant atherosclerotic stenosis. Thus, a personalized approach is especially important for treatment and diagnostics of internal carotid artery tortuosity.

Hemodynamic Changes in Intrarenal Blood Flow are Associated With Poor Prognosis in Patients With Acute Decompensated Heart Failure.

AIM: To evaluate a potential role of different patterns of intrarenal blood flow using Doppler ultrasound as a part of determining the severity of venous congestion, predicting impairment of renal function and an unfavorable prognosis in patients with acute decompensated chronic heart failure (ADCHF). MATERIAL AND METHODS: This prospective observational single-site study included 75 patients admitted in the intensive care unit for ADCHF. Upon admission all patients underwent bedside renal venous Doppler ultrasound to determine the blood flow pattern (continuous, biphasic, monophasic). In one hour after the initiation of intravenous diuretic therapy, sodium concentration was measured in a urine sample. The primary endpoint was the development of acute kidney injury (AKI). The secondary endpoints were the development of diuretic resistance (a need to increase the furosemide daily dose by more than 2 times compared with the baseline), decreased natriuretic response (defined as urine sodium concentration less than 50-70 mmol/l), and in-hospital death. RESULTS: According to the data of Doppler ultrasound, normal renal blood flow was observed in 40 (53%) patients, biphasic in 21 (28%) patients, and monophasic in 14 (19%) patients. The monophasic pattern of intrarenal blood flow was associated with the highest incidence of AKI: among 14 patients in this group, AKI developed in 100% of cases (OR 3.8, 95% CI: 2.5-5.8, p<0.01), while among patients with normal and moderate impairment of renal blood flow, there was no significant increase in the risk of developing AKI. The odds of in-hospital death were increased 25.77 times in patients with monophasic renal blood flow (95% CI: 5.35-123.99, p<0.001). Patients with a monophasic intrarenal blood flow pattern were also more likely to develop diuretic resistance compared to patients with other blood flow patterns (p<0.001) and had a decreased sodium concentration to less than 50 mmol/l (p<0.001) in a spot urine test obtained one hour after the initiation of furosemide administration. CONCLUSION: Patients with monophasic intrarenal blood flow are at a higher risk of developing AKI, diuretic resistance with decreased natriuretic response, and in-hospital death.

Edema of the upper extremity on the unaffected side in unilateral breast cancer patients.

Breast cancer-related lymphedema (BCRL) occurs usually on the affected side, and its cause and pathophysiology are well known. However, the cause of edema of the upper extremity on the unaffected side is barely known. It is often considered to be chemotherapy-induced general edema, and clinical evaluation is rarely performed in these patients. This study aimed to present the clinical characteristics of unilateral breast cancer patients with edema of upper extremity on the unaffected side, and to emphasize the importance of early diagnosis and medical interventions. This study retrospectively analyzed the medical records of unilateral breast cancer patients complaining edema of upper extremity on the unaffected side, from January 2020 to May 2021. Lymphoscintigraphy was used to assist in confirming the diagnosis of lymphedema, and Doppler ultrasonography or 3D computed tomography angiography were performed to differentiate vascular problems. Fourteen patients were enrolled in the study. Seven, 3, and 4 patients had edema of both upper extremities, edema of the upper extremity on the unaffected side only, and edema of all extremities, respectively. None of the 4 patients with edema of all extremities showed abnormal findings on examination. In patients with edema in the upper extremity on the unaffected side alone, lymphatic flow dysfunction was seen in 2 patients, and deep vein thrombosis (DVT) was diagnosed in 1. In patients with edema of both upper extremities, lymphatic flow dysfunction was seen in 2 patients, and DVT was diagnosed in 3. One patient had DVT and accompanying lymphatic flow dysfunction. Lymphedema and DVT were diagnosed in a number of patients with edema of the upper extremity on the unaffected side, and lymphedema can occur without direct injury to the lymphatic flow system. Therefore, clinicians should not overlook the fact that diseases that require early diagnosis and treatment can occur in patients with edema of the unaffected upper extremity.

Modelling lower-limb peripheral arterial disease using clinically available datasets: impact of inflow boundary conditions on hemodynamic indices for restenosis prediction.

BACKGROUND AND OBJECTIVES: The integration of hemodynamic markers as risk factors in restenosis prediction models for lower-limb peripheral arteries is hindered by fragmented clinical datasets. Computed tomography (CT) scans enable vessel geometry reconstruction and can be obtained at different times than the Doppler ultrasound (DUS) images, which provide information on blood flow velocity. Computational fluid dynamics (CFD) simulations allow the computation of near-wall hemodynamic indices, whose accuracy depends on the prescribed inlet boundary condition (BC), derived from the DUS images. This study aims to: (i) investigate the impact of different DUS-derived velocity waveforms on CFD results; (ii) test whether the same vessel areas, subjected to altered hemodynamics, can be detected independently of the applied inlet BC; (iii) suggest suitable DUS images to obtain reliable CFD results. METHODS: CFD simulations were conducted on three patients treated with bypass surgery, using patient-specific DUS-derived inlet BCs recorded at either the same or different time points than the CT scan. The impact of the chosen inflow condition on bypass hemodynamics was assessed in terms of wall shear stress (WSS)-derived quantities. Patient-specific critical thresholds for the hemodynamic indices were applied to identify critical luminal areas and compare the results with a reference obtained with a DUS image acquired in close temporal proximity to the CT scan. RESULTS: The main findings indicate that: (i) DUS-derived inlet velocity waveforms acquired at different time points than the CT scan led to statistically significantly different CFD results (p<0.001); (ii) the same luminal surface areas, exposed to low time-averaged WSS, could be identified independently of the applied inlet BCs; (iii) similar outcomes were observed for the other hemodynamic indices if the prescribed inlet velocity waveform had the same shape and comparable systolic acceleration time to the one recorded in close temporal proximity to the CT scan. CONCLUSIONS: Despite a lack of standardised data collection for diseased lower-limb peripheral arteries, an accurate estimation of luminal areas subjected to altered near-wall hemodynamics is possible independently of the applied inlet BC. This holds if the applied inlet waveform shares some characteristics - derivable from the DUS report - as one matching the acquisition time of the CT scan.

Comparison of Doppler Imaging and Microvascular Imaging in Cervical Lymph Node Blood Flow Analysis.

Cervical lymph node metastasis is an important determinant of cancer stage and the selection of an appropriate treatment plan for patients with head and neck cancer. Therefore, metastatic cervical lymph nodes should be effectively differentiated from lymphoma, tuberculous lymphadenitis, and other benign lymphadenopathies. The aim of this work is to describe the performance of Doppler ultrasound and superb microvascular imaging (SMI) in evaluating blood flow information of cervical lymph nodes. In addition, the features of flow imaging in metastatic lymph nodes, lymphoma, and tuberculous lymphadenitis were described. Compared with Doppler ultrasound, SMI, the latest blood flow imaging technology, could detect more blood flow signals because the sensitivity, specificity, and accuracy of SMI in the diagnosis of cervical lymph node disease were higher. This article summarizes the value of Doppler ultrasound and SMI in evaluating cervical lymph node diseases and focuses on the diagnostic performance of SMI.

Fetal Hepatic Hemangioma Diagnosed in Utero Using Doppler Microvascular Imaging.

A 35-year-old pregnant woman was referred to our institution at 33 weeks' gestation for evaluation of a fetal abdominal tumor. B-mode ultrasonography demonstrated a massive lesion. Bidirectional power Doppler mode showed abundant blood flow surrounding the tumor. On superb micro-vascular imaging, various Doppler signal patterns were observed within the tumor, including diffuse fine dotted-like signals, linear flow, and internal shunt flow. Sequential observations of the tumor and cardiac cycles also revealed pulsatile flow beneath the edges of the tumor and continuous fine flow in the central area, resembling a 'centripetal fill-in' appearance on contrast computed tomography. Therefore, we assumed the fetal tumor to be a hepatic hemangioma. Fetal heart failure was detected at 37 weeks' gestation, and a 2,484-g female infant was delivered with 1- and 5-min Apgar scores of 7 and 8, respectively. A postnatal contrast computed tomography examination showed a progressive centripetal fill-in appearance, leading to a diagnosis of hepatic hemangioma. Kasabach-Merritt syndrome was also noted. Intensive treatment was performed, and the infant was discharged at 3 months after birth. In summary, we experienced a case of hepatic hemangioma diagnosed in utero using superb micro-vascular imaging. And basing seamless postnatal treatments on prenatal imaging findings may help to reduce the perinatal mortality.

Doppler ultrasound surveillance of recently formed haemodialysis arteriovenous fistula: the SONAR observational cohort study.

Background: Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure. Objective: To assess the feasibility of performing a randomised controlled trial that examines whether, by informing early and effective salvage intervention of fistulas that would otherwise fail, Doppler ultrasound surveillance of developing arteriovenous fistulas improves longer-term arteriovenous fistula patency. Design: A prospective multicentre observational cohort study (the 'SONAR' study). Setting: Seventeen haemodialysis centres in the UK. Participants: Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created. Intervention: Participants underwent Doppler ultrasound surveillance of their arteriovenous fistulas at 2, 4, 6 and 10 weeks after creation, with clinical teams blinded to the ultrasound surveillance findings. Main outcome measures: Fistula maturation at week 10 defined according to ultrasound surveillance parameters of representative venous diameter and blood flow (wrist arteriovenous fistulas: ≥ 4 mm and > 400 ml/minute; elbow arteriovenous fistulas: ≥ 5 mm and > 500 ml/minute). Mixed multivariable logistic regression modelling of the early ultrasound scan data was used to predict arteriovenous fistula non-maturation by 10 weeks and fistula failure at 6 months. Results: A total of 333 arteriovenous fistulas were created during the study window (47.7% wrist, 52.3% elbow). By 2 weeks, 37 (11.1%) arteriovenous fistulas had failed (thrombosed), but by 10 weeks, 219 of 333 (65.8%) of created arteriovenous fistulas had reached maturity (60.4% wrist, 67.2% elbow). Persistently lower flow rates and venous diameters were observed in those fistulas that did not mature. Models for arteriovenous fistulas' non-maturation could be optimally constructed using the week 4 scan data, with fistula venous diameter and flow rate the most significant variables in explaining wrist fistula maturity failure (positive predictive value 60.6%, 95% confidence interval 43.9% to 77.3%), whereas resistance index and flow rate were most significant for elbow arteriovenous fistulas (positive predictive value 66.7%, 95% confidence interval 48.9% to 84.4%). In contrast to non-maturation, both models predicted fistula maturation much more reliably [negative predictive values of 95.4% (95% confidence interval 91.0% to 99.8%) and 95.6% (95% confidence interval 91.8% to 99.4%) for wrist and elbow, respectively]. Additional follow-up and modelling on a subset (n = 192) of the original SONAR cohort (the SONAR-12M study) revealed the rates of primary, assisted primary and secondary patency arteriovenous fistulas at 6 months were 76.5, 80.7 and 83.3, respectively. Fistula vein size, flow rate and resistance index could identify primary patency failure at 6 months, with similar predictive power as for 10-week arteriovenous fistula maturity failure, but with wide confidence intervals for wrist (positive predictive value 72.7%, 95% confidence interval 46.4% to 99.0%) and elbow (positive predictive value 57.1%, 95% confidence interval 20.5% to 93.8%). These models, moreover, performed poorly at identifying assisted primary and secondary patency failure, likely because a subset of those arteriovenous fistulas identified on ultrasound surveillance as at risk underwent subsequent successful salvage intervention without recourse to early ultrasound data. Conclusions: Although early ultrasound can predict fistula maturation and longer-term patency very effectively, it was only moderately good at identifying those fistulas likely to remain immature or to fail within 6 months. Allied to the better- than-expected fistula patency rates achieved (that are further improved by successful salvage), we estimate that a randomised controlled trial comparing early ultrasound-guided intervention against standard care would require at least 1300 fistulas and would achieve only minimal patient benefit. Trial Registration: This trial is registered as ISRCTN36033877 and ISRCTN17399438. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135572) and is published in full in Health Technology Assessment; Vol. 28, No. 24. See the NIHR Funding and Awards website for further award information.

For people with advanced kidney disease, haemodialysis is best provided by an 'arteriovenous fistula', which is created surgically by joining a vein onto an artery at the wrist or elbow. However, these take about 2 months to develop fully ('mature'), and as many as 3 out of 10 fail to do so. We asked whether we could use early ultrasound scanning of the fistula to identify those that are unlikely to mature. This would allow us to decide whether it would be practical to run a large, randomised trial to find out if using early ultrasound allows us to 'rescue' fistulas that would otherwise fail. We invited adults to undergo serial ultrasound scanning of their fistula in the first few weeks after it was created. We then analysed whether we could use the data from the early scans to identify those fistulas that were not going to mature by week 10. Of the 333 fistulas that were created, about two-thirds reached maturity by week 10. We found that an ultrasound scan 4 weeks after fistula creation could reliably identify those fistulas that were going to mature. However, of those fistulas predicted to fail, about one-third did eventually mature without further intervention, and even without knowing what the early scans showed, another third were successfully rescued by surgery or X-ray-guided treatment at a later stage. Performing an early ultrasound scan on a fistula can provide reassurance that it will mature and deliver trouble-free dialysis. However, because scans are poor at identifying fistulas that are unlikely to mature, we would not recommend their use to justify early surgery or X-ray-guided treatment in the expectation that this will improve outcomes.

Effect of systemic vascular resistance on the agreement between stroke volume by non-invasive pulse wave analysis and Doppler ultrasound in healthy volunteers.

BACKGROUND: Stroke volume can be estimated beat-to-beat and non-invasively by pulse wave analysis (PWA). However, its reliability has been questioned during marked alterations in systemic vascular resistance (SVR). We studied the effect of SVR on the agreement between stroke volume by PWA and Doppler ultrasound during reductions in stroke volume in healthy volunteers. METHODS: In a previous study we simultaneously measured stroke volume by PWA (SVPWA) and suprasternal Doppler ultrasound (SVUS). We exposed 16 healthy volunteers to lower body negative pressure (LBNP) to reduce stroke volume in combination with isometric hand grip to elevate SVR. LBNP was increased by 20 mmHg every 6 minutes from 0 to 80 mmHg, or until hemodynamic decompensation. The agreement between SVPWA and SVUS was examined using Bland-Altman analysis with mixed regression. Within-subject limits of agreement (LOA) was calculated from the residual standard deviation. SVRUS was calculated from SVUS. We allowed for a sloped bias line by introducing the mean of the methods and SVRUS as explanatory variables to examine whether the agreement was dependent on the magnitude of stroke volume and SVRUS. RESULTS: Bias ± limits of agreement (LOA) was 27.0 ± 30.1 mL. The within-subject LOA was ±11.1 mL. The within-subject percentage error was 14.6%. The difference between methods decreased with higher means of the methods (-0.15 mL/mL, confidence interval (CI): -0.19 to -0.11, P<0.001). The difference between methods increased with higher SVRUS (0.60 mL/mmHg × min × L-1, 95% CI: 0.48 to 0.72, P<0.001). CONCLUSION: PWA overestimated stroke volume compared to Doppler ultrasound during reductions in stroke volume and elevated SVR in healthy volunteers. The agreement between SVPWA and SVUS decreased during increases in SVR. This is relevant in settings where a high level of reliability is required.