Search results for " Doppler"
showing 10 items of 373 documents
Experimental Percutaneous Cannulation of the Supraorbital Arteries: Implication for Future Therapy
2005
Purpose There is some evidence to suggest that thrombolysis has a beneficial effect in retinal vessel occlusion. However, there is concern that this therapeutic approach carries the risk of hemorrhage. Retrograde cannulation of the supraorbital arteries followed by irrigation with fibrinolytic agents may have the potential to minimize the risk of major complications. The study was conducted to investigate the anatomic and sonographic features of the supraorbital arteries. Methods This cadaver dissection study was performed on the orbits of 12 cadaveric specimens. In each orbit, the supraorbital region was dissected, followed by cannulation of the supraorbital vessels and injection of ink. I…
Intraoperative monitoring of cerebral microcirculation and oxygenation--a feasibility study using a novel photo-spectrometric laser-Doppler flowmetry.
2009
The present study assesses the utility of a novel invasive device (O2C-, oxygen-to-see-device) for intraoperative measurement of the cerebral microcirculation. CO2 vasoreactivity during 2 different propofol concentrations was used to investigate changes of capillary venous cerebral blood flow (rvCBF), oxygen saturation (srvO2), and hemoglobin concentration (rvHb) during craniotomy.Thirty-four patients were randomly assigned to a low propofol (4 mg/kg/h) versus a high propofol (6 mg/kg/h) group. A fiberoptic probe was applied on the cortex next to the surgical site. Measurements were performed during lower (35 mm Hg) and higher (45 mm Hg) levels of partial pressure of carbon dioxide (paCO2).…
Improvement of tricuspid regurgitation after pulmonary thromboendarterectomy
2002
For patients with chronic thromboembolic pulmonary hypertension who undergo pulmonary thromboendarterectomy (PTE) it has not yet been systematically investigated how operation affects the severity of tricuspid regurgitation (TR). This study sought (1) to evaluate the extent of TR reversibility after operation, (2) to identify potential predictors of the reversibility of TR, and (3) to investigate the influence of geometric and hemodynamic alterations on the extent of TR severity.Thirty-nine patients (55+/-12 years) undergoing PTE without tricuspid valve repair were investigated before and 13+/-8 days after operation by Doppler color flow mapping. Geometry of the tricuspid valve as well as r…
Infrequent early recanalization of greater saphenous vein after endovenous laser treatment
2003
Abstract Objective The frequency of recanalization of the greater saphenous vein (GSV) after endovenous laser treatment (ELT) is unclear. This study was undertaken to establish the incidence of early recanalization after ELT and to study the histopathologic features of reperfused and excised GSV. Methods One hundred nine GSV in 85 consecutive patients with clinical stage C 2-6 E P,S A S,P,D P R disease were treated with ELT. Twelve months of follow-up with duplex scanning at regular intervals was possible in 104 treated veins (95.4%) in 82 patients (96.5%). Recanalized vessels were removed surgically and examined at histopathology. Results ELT-induced occlusion proved permanent at duplex sc…
Agenesis of the renal segment of inferior vena cava associated with venous stasis.
2010
Congenital anomalies of the inferior vena cava is an extremely rare vascular anomaly with controversial pathogenesis. Anomalies of the inferior vena cava (IVC) are present in 0.3% to 0.5% of otherwise healthy individual and in 0.6% to 2% of patients with other cardiovascular defects. The phenomenon of absence of the IVC has been described in a variety of ways such as absence, agenesis, anomalous, and interruption of a particular segment ([infra] hepatic, pre-renal, renal, or infrarenal) of the IVC. We describe a 42-year-old man with chronic venous insufficiency, without DVT, caused by congenital absence of renal segment of the IVC
Beta-adrenergic stimulation enhances left ventricular diastolic performance in normal subjects.
1997
To determine the effects of beta-adrenergic stimulation on transmitral Doppler echocardiography flow characteristics of left ventricular diastolic filling, we studied 10 healthy volunteers aged 23-31 years (mean age, 26.6 years) during intravenous infusion of isoprenaline in consecutive steps of 0.1, 0.2, 0.4, 0.75, and 1.5 micrograms/min (each for 15 min). Saline control infusion was given in the same manner in a crossover and blinded protocol. Compared with the infusion of placebo, stepwise increasing doses of isoprenaline caused a dose-related increase in early and late diastolic filling velocities and velocity-time integrals, a lengthening of the acceleration time, and a shortening of t…
Image-Guided Transcranial Doppler Ultrasound for Monitoring Posthemorrhagic Vasospasms of Infratentorial Arteries: A Feasibility Study
2019
Background A considerable number of patients with subarachnoid hemorrhage (SAH) develop vasospasms of the infratentorial arteries. Transcranial Doppler sonography (TCD) is used to screen for vasospasm. In this study, we used a technical modification that combines TCD with an image guidance device that the operator can use to navigate to the ultrasonic window and to predefined intracranial vascular targets. Our aim was to analyze the feasibility, spatial precision, and spatial reproducibility of serial image-guided TCD of infratentorial and—for comparison—supratentorial arteries in the clinical setting of monitoring for vasospasm after SAH. Methods The study included 10 SAH patients, who eac…
Incidentally discovered thyroid nodules: incidence, and greyscale and colour Doppler pattern in an adult population screened by real-time compound sp…
2006
Purpose. Our aim was to assess the incidence and ultrasound features of thyroid nodules in an adult population screened by means of high-resolution ultrasonography (HRUS) and to evaluate the contribution of real-time spatial compound sonography (CS) in terms of image quality. Materials and methods. A total of 704 consecutive patients (400 women, 304 men) without thyroid disease underwent HRUS and CS examination of the thyroid gland. Number, size, location, echotexture and colour Doppler pattern of detected nodules were assessed. Two radiologists also assessed image quality of the two techniques. Results. Seven hundred and eleven thyroid nodules (size range 0.18-4.1 cm; mean: 1.1 cm) were de…
Local Gingival Blood Flow at Healthy and Inflamed Sites Measured by Laser Doppler Flowmetry
2006
This investigation aimed to: 1) develop a method to obtain reproducible laser Doppler flow readings (LDFRs) at the gingiva of the maxillary front teeth; 2) evaluate regional gingival blood flow (GBF) in healthy gingiva by laser Doppler flowmetry; 3) compare hand-held LDFR (H-LDFR) with splint LDFR (S-LDFR); and 4) monitor changes in GBF in experimental gingivitis (EG) and chronic gingivitis (CG).The LDFR, gingival index (GI), and plaque index (PI) were measured at 13 gingival sites (teeth #6 to #11) in 10 healthy volunteers (five males and five females), 23 to 34 years of age, over a period of 12.5 +/- 3.27 days employing a partial-mouth EG model and in 11 patients (three males and eight fe…
Serial Measurement of Static and Dynamic Cerebrovascular Autoregulation After Brain Injury
2011
In patients with neuronal injury, the knowledge of the status of cerebrovascular autoregulation can help to optimize the management of the cerebral perfusion pressure. This study characterizes dynamic and static cerebrovascular autoregulation during the first 7 days after severe traumatic brain injury or intracranial hemorrhage.After approval from the IRB, 16 patients were studied. Cerebral blood flow velocity (CBFV) was measured daily for the assessment of dynamic (10 patients) and static (16 patients) cerebrovascular autoregulation in both the middle cerebral arteries using the transcranial Doppler sonography. Dynamic cerebrovascular autoregulation (dAR) was measured using the cuff-deflat…