End-diastolic velocity mediates the relationship between renal resistive index and the risk of death.

Objective: Renal resistive index predicts the risk of death in many populations but the mechanism linking renal resistive index and death remains elusive. Renal resistive index is derived from end-diastolic velocity (EDV) and peak systolic velocity (PSV). However, the predictive value of EDV or PSV considered alone is unknown.

Early changes in renal resistive index and mortality in diabetic and nondiabetic kidney transplant recipients: a cohort study.

Background: Renal resistive index (RI) predicts mortality in renal transplant recipients (RTR). However, its predictive value may be different according to the time of measurement. We analysed RI changes between 1 month and 3 months after transplantation and its predictive value for death with a functioning graft (DWFG).

The association between renal resistive index and premature mortality after kidney transplantation is modified by pre-transplant diabetes status: a cohort study.

Background: Renal resistive index (RI) predicts mortality in renal transplant recipients, but we do not know whether this is true in diabetic patients. The objective of this study was to analyse the long-term predictive value of RI for death with a functioning graft (DWFG) in renal transplant recipients with or without pre-transplant diabetes.

Methods: We conducted a retrospective study in 1800 renal transplant recipients between 1985 and 2017 who were followed for up to 30 years (total observation period: 14 202 patient years).

Impact on renal resistive index of diabetes in renal transplant donors and recipients: A retrospective analysis of 1827 kidney transplant recipients.

High renal resistive index (RI) is observed in diabetes and is associated with poor patient survival, but whether it is primarily due to renal vascular resistance or systemic vascular alterations is unclear. The respective impact of kidney transplant from diabetic donors or to diabetic recipients on RI would shed some light on this issue. The objective of the study was to analyze the impact of donor and recipient diabetes on RI in order to understand the respective impact of the kidney and the vascular environment.

Barriers and Advances in Kidney Preservation.

Despite the fact that a significant fraction of kidney graft dysfunctions observed after transplantation is due to ischemia-reperfusion injuries, there is still no clear consensus regarding optimal kidney preservation strategy. This stems directly from the fact that as of yet, the mechanisms underlying ischemia-reperfusion injury are poorly defined, and the role of each preservation parameter is not clearly outlined. In the meantime, as donor demography changes, organ quality is decreasing which directly increases the rate of poor outcome.

Evaluation of Doppler-ultrasonography in the diagnosis of transjugular intrahepatic portosystemic shunt dysfunction: A prospective study.

Aim: To prospectively evaluate the performance of Doppler-ultrasonography (US) for the detection of transjugular intrahepatic portosystemic shunt (TIPS) dysfunction within a multicenter cohort of cirrhotic patients.

Methods: This study was conducted in 10 french teaching hospitals. After TIPS insertion, angiography and liver Doppler-US were carried out every six months to detect dysfunction (defined by a portosystemic gradient ≥ 12 mmHg and/or a stent stenosis ≥ 50%).

Renal auto-transplantation promotes cortical microvascular network remodeling in a preclinical porcine model.

The vascular network is a major target of ischemia-reperfusion, but has been poorly investigated in renal transplantation. The aim of this study was to characterize the remodeling of the renal vascular network that follows ischemia-reperfusion along with the most highly affected cortex section in a preclinical renal transplantation model. There were two experimental groups.

Effect of injection current and temperature on signal strength in a laser diode optical feedback interferometer.

We present a simple analytical model that describes the injection current and temperature dependence of optical feedback interferometry signal strength for a single-mode laser diode. The model is derived from the Lang and Kobayashi rate equations, and is developed both for signals acquired from the monitoring photodiode (proportional to the variations in optical power) and for those obtained by amplification of the corresponding variations in laser voltage. The model shows that both the photodiode and the voltage signal strengths are dependent on the laser slope efficiency, which itself is a function of the injection current and the temperature.

Liver fibrosis staging with contrast-enhanced ultrasonography: prospective multicenter study compared with METAVIR scoring.

We prospectively assessed contrast-enhanced sonography for evaluating the degree of liver fibrosis as diagnosed via biopsy in 99 patients. The transit time of microbubbles between the portal and hepatic veins was calculated from the difference between the arrival time of the microbubbles in each vein. Liver biopsy was obtained for each patient within 6 months of the contrast-enhanced sonography.

Normal ultrasound anatomy of the triangular fibrocartilage of the wrist: a study on cadavers and on healthy subjects.

Purpose: To report the normal sonographic anatomy of the triangular fibrocartilage (TFC) of the wrist in cadavers and volunteers.

Method: Five hands from cadavers were examined sonographically before and after wrist dissection, during which the TFC was marked with surgical wires. Twenty volunteers without wrist limitation or pain, and without any history of wrist disease or inflammatory arthritis (mean age, 26 years (range,19-45 years) were also examined.

Role of parametric imaging in contrast-enhanced sonography of hepatic focal nodular hyperplasia.

Purpose: To assess the value of parametric imaging during contrast-enhanced sonographic examination in the diagnosis of focal nodular hyperplasia (FNH) of the liver.

Materials And Methods: Thirty-one patients with solitary FNH underwent contrast-enhanced sonographic examination between January 2003 and June 2004 using SonoVue and a Sequoia scanner equipped with Cadence Contrast Pulse Sequencing software. Contrast enhancement from a time sequence of perfusion frames was estimated using QontraXt software, which provides quantification of perfusion parameters.

Differential diagnosis of focal nodular hyperplasia with quantitative parametric analysis in contrast-enhanced sonography.

Objectives: We investigated the potential of quantitative parametric analysis in the differential diagnosis of focal nodular hyperplasia (FNH) from other hypervascularized liver focal lesions.

Materials And Methods: Eighty-five focal liver lesions (in 83 patients) were explored using contrast-enhanced ultrasound (SonoVue and Cadence Contrast Pulse Sequencing) consisting of typical FNH (n=52), hepatocellular carcinoma (n=11), hemangioma with high flow (n=8), hypervascular metastases (n=10), and hepatocellular adenoma (n=4). QontraXt software (AMID, Italy) was used here to estimate the following parameters: maximum peak value, Tr (time corresponding to time for obtaining 63% of the plateau), beta parameter corresponding to the exponential factor, and slope corresponding to the tangent value of the first phase of enhancement.

Venous stagnation induced by 7 days in HDT, in the cerebral, ophthalmic, renal and splanchnic territories.

The scientific objectives was to quantify the vascular changes in the brain, eye fundus, renal parenchyma, and splanchnic network. Heart, portal, jugular, femoral veins were investigate by Echography. The cerebral mesenteric, renal and ophthalmic arteries were investigated by Doppler.

Influence of otoliths and neck muscle receptors on peripheral hemodynamic regulation.

To evaluate the cardiovascular changes induced by otoliths and neck mechanoreceptors stimulation during head movements, nine subjects in supine prone position performed passive head-down neck flexion (P.Ext) and head up P.Extension (P.

Modalities of surveillance after carotid endarterectomy: impact of surgical technique.

The purpose of this study was to assess the need for follow-up duplex scan (DS) 1 year after carotid endarterectomy (CE) performed with prosthetic patching and intraoperative completion arteriography. Between April 1994 and December 2000, a total of 605 CE procedures with prosthetic patch closure and intraoperative completion arteriography were performed in 540 patients. All patients underwent DS at 4 days and then yearly after the procedure.

Carotid bypass with polytetrafluoroethylene grafts: a study of 110 consecutive patients.

Background: Carotid endarterectomy (CEA) is the standard treatment for atherosclerotic lesions involving the carotid bifurcation. However, CEA can be challenging under some conditions. We describe the technique and outcome of prosthetic carotid bypass grafting (PCB) with polytetrafluoroethylene (PTFE) grafts as an elective alternative to CEA.

3D realtime echography and echography assisted by a robotic arm for investigating astronauts in the ISS from the ground.

As human will stay for long duration in isolated sites like ISS there will be a need to perform quick and reliable diagnosis to evaluate the gravity of the pathology in presence of clinical symptoms. Many pathological situations (abnormal heart rate, pericardic collection, mitral prolaps, cholecystis, renal lithiasis, normal and ectopic pregnancies, ovarian cyst, acute appendicitis, phlebitis ..

Cardiac, cerebral & lower limb hemodynamic changes, during HDT (5 days to 42 d) & space flights (7 days to 6 months).

The objective was to identify the major cardiovascular changes induced by exposure to real or simulated 0 g (spaceflights: 6 days, 14 d, 21 d, 25 d, 6 months; Head Down Tilt: 10 h, 4 d, 5 d, 7 d, 30 d, 42 d), with a minimum of countermeasure (Daily exercise in space, no exercise in HDT).

Effect of human head flexion on the control of peripheral blood flow in microgravity and in 1 g.

This study evaluated, in six healthy subjects, whether head flexion, which stimulates the vestibular system and the tonic neck receptors, interferes with cardiovascular regulation. Arterial parameters were measured continuously using a pulsed Doppler ultrasound probe during parabolic flights with subjects either in the supine craned-head position (control) or in the supine anterior neck flexion bent-neck position. Exposure to 0 g induced a fluid shift towards the head (stroke volume +8%, P<0.

Adaptation of the left heart, cerebral and femoral arteries, and jugular and femoral veins during short- and long-term head-down tilt and spaceflights.

The objective of this investigation was to identify the major cardiovascular changes induced by exposure to real or simulated Og (spaceflights: 6, 14, 21 and 25 days, and 6 months; head down tilt, HDT: 10 h, 4, 5, 7, 30 and 42 days), with a minimum of counter-measures. The following cardiovascular data were measured by echocardiography and Doppler ultrasonography: left ventricle end-diastolic volume (LVDV), stroke volume (SV), cardiac output (CO), ejection fraction (EF), middle cerebral artery flow velocity (Qca), femoral artery flow velocity (Qfa), cerebral vascular resistance (Rca), femoral vascular resistance (Rfa), jugular vein cross-sectional area (Ajv), femoral vein cross-sectional area (Afv), heart rate (HR), and mean blood pressure (MBP). LVDV remained decreased compared to pre-HDT or pre-flight levels after 1 week of spaceflight or HDT (-8 to -13%, P<0.

Doppler measurement of cerebral and lower limb flow during a lower body negative pressure test for predicting orthostatic intolerance.

Objective: To quantify the cardiovascular response to an orthostatic test for predicting orthostatic intolerance.

Methods: Cerebral and lower limb arterial flow and resistance were assessed by Doppler ultrasonography during lower body negative pressure (7 minutes each at -25 and -45 mm Hg). Cardiovascular deconditioning was induced by 42 days in head-down tilt at -6 degress (7 subjects) and 6-month spaceflights (10 cosmonauts).