Search results for "DOPPLER"
showing 10 items of 637 documents
Cerebrovascular and cardiovascular variability interactions investigated through conditional joint transfer entropy in subjects prone to postural syn…
2017
Objective: A model-based conditional transfer entropy approach was exploited to quantify the information transfer in cerebrovascular (CBV) and cardiovascular (CV) systems in subjects prone to develop postural syncope. Approach: Spontaneous beat-to-beat variations of mean cerebral blood flow velocity (MCBFV) derived from a transcranial Doppler device, heart period (HP) derived from surface electrocardiogram, mean arterial pressure (MAP) and systolic arterial pressure (SAP) derived from finger plethysmographic arterial pressure device were monitored at rest in supine position (REST) and during 60° head-up tilt (TILT) in 13 individuals (age mean ± standard deviation: 28 ± 9 years, min-max r…
Inhibition of neutral endopeptidase (NEP) facilitates neurogenic inflammation
2005
Neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE) are involved in neuropeptide degradation and may modulate neurogenic inflammation. We therefore explored the effect of specific blockers of NEP and ACE on the intensity of neurogenic inflammation. We investigated eight subjects on three occasions. Two pairs of microdialysis fibers equipped with intraluminal wires were inserted intracutaneously into the volar forearms and electrical stimuli were delivered via the intraluminal electrodes. The microdialysis fibers were perfused either with normal saline, phosphoramidon (NEP inhibitor), or captopril (ACE inhibitor). CGRP release was assessed in the microdialysis eluate via a sp…
Unexpected middle cerebral artery peak systolic velocity values in the normal fetal population. Are they a matter of concern?
2018
AbstractObjective: The aim of this study was to investigate in the fetus the relationship between unexpected high middle cerebral artery peak systolic velocity (middle cerebral artery (MCA) peak sy...
Diagnostic accuracy of current sonographic criteria for the detection of outflow abnormalities in the internal jugular veins
2012
Objectives: This study was aimed at evaluation of the diagnostic value of Doppler sonography for the assessment of abnormalities in the internal jugular veins (IJVs). Method: One hundred and sixteen IJVs were assessed in 58 patients with associated multiple sclerosis. Findings of Doppler sonography were compared with results of the reference test: catheter venography. Results: At least one positive extracranial sonographic criterion suggesting venous abnormality was found in 92.2% of the assessed veins. Yet, sensitivity, specificity, positive and negative predictive values of sonography were low: 93.4%, 12.0%, 79.4% and 33.3% for at least one positive criterion, and for at least two positiv…
Extracranial Venous Drainage Pattern in Multiple Sclerosis and Healthy Controls: Application of the 2011 Diagnostic Criteria for Chronic Cerebrospina…
2015
The etiology of multiple sclerosis (MS) is still largely unknown and it has been proposed that an impaired venous drainage from the central nervous system, defined as chronic cerebrospinal venous insufficiency (CCSVI), may play a role in this. We investigated the prevalence of extracranial venous drainage pattern alterations in a cohort of MS patients based on the 2011 revised diagnostic criteria for CCSVI. Thirty-nine MS patients and 18 healthy subjects underwent blinded extra-cranial venous echo-color Doppler sonography to reveal the presence of CCSVI. There was no statistically significant difference between MS patients and healthy controls regarding CCSVI prevalence (p value = 0.53). Th…
Image-guided transcranial Doppler sonography for monitoring of vasospasm after subarachnoid hemorrhage.
2016
Transcranial Doppler ultrasound (TCD) is a standard method for bedside vasospasm monitoring after subarachnoid hemorrhage (SAH). Image guidance has previously been shown to reduce intra- and interobserver variability of this method. The aim of the present study was to compare image-guided and conventional TCD in vasospasm monitoring after SAH.418 TCD exams of 24 consecutive SAH patients registered in a database were evaluated. Of these, 130 image-guided exams were identified which had been performed on the same day as conventional Doppler exams. These matched pairs were taken for statistical analysis. Data were tested statistically using the sign test applied at patient level to aggregated …
Vascular mapping of the face: B-mode and doppler ultrasonography study.
2015
Background To analyze the face vascularization pattern using B-mode and Doppler ultrasonography, and also propose an arterial vessel mapping. Material and Methods The investigation was performed on 20 ultrasonography exams of facial vessels through linear and endocavitary transducers. We analyzed and determined the average values for diameters, peak systolic velocity and resistive index of the following arteries: external carotid, lingual, deep lingual, sublingual, facial, submental, inferior labial, superior labial, angular, maxillary inferior alveolar, mental, buccal, greater palatine, infraorbital, superficial temporal, transverse facial and frontal. Results Data was obtained allowing th…
PANCREATIC CARCINOMA VERSUS CHRONIC FOCAL PANCREATITIS: CONTRAST-ENHANCED POWER DOPPLER ULTRASONOGRAPHY FINDINGS
2005
Background: We assessed the potential usefulness of contrast-enhanced power Doppler ultrasonography (US) for differentiating pancreatic carcinoma from chronic focal pancreatitis. Methods: Twenty-six consecutive patients with ductal carcinoma (n=16) and chronic focal pancreatitis (n=10) underwent power Doppler US examinations before and after intravenous injection of an air-based contrast agent (Levovist, Schering, Berlin, Germany). Final diagnosis was obtained by surgery in all patients. The following parameters before and after intravenous administration of contrast agent were evaluated for each lesion: number, morphology and course of the vessels within the lesion and time to maximum dete…
Case report: acute portal vein thrombosis associated with acute cytomegalovirus infection in an immunocompetent adult
2017
Cytomegalovirus (CMV) infection is usually asymptomatic and self-limiting in healthy individuals, but significant complications can develop in immunosuppressed patients. Venous or arterial thromboembolic phenomena are uncommon yet very serious complications of CMV infection. Most published reports describe immunosuppressed patients, but thrombotic events in CMV-infected immunocompetent individuals may also occur. We describe the case of an immunocompetent young man with acute CMV hepatitis that was complicated with portal vein thrombosis (PVT). We also review the literature regarding the association between PVT and CMV in immunocompetent patients. Thromboembolism is an underestimated but si…
The Prevalence of Chronic Cerebrospinal Venous Insufficiency in Meniere Disease: 24-Month Follow-up after Angioplasty
2016
Abstract Purpose To evaluate relationship between Meniere disease (MD) and chronic cerebrospinal venous insufficiency (CCSVI) using ultrasound, magnetic resonance (MR) imaging, and venography and to evaluate the effectiveness of angioplasty of the internal jugular vein (IJV) and azygos vein (AV) in reducing symptoms of MD. Materials and Methods Patients with a confirmed diagnosis of MD unresponsive to standard treatment underwent duplex ultrasound and MR imaging to diagnose CCSVI. Healthy volunteers were also studied to evaluate CCSVI in asymptomatic subjects. Patients with CCSVI and MD underwent venography and percutaneous transluminal angioplasty (PTA) of IJV and AV. Results There were 18…