The Experts below are selected from a list of 156 Experts worldwide ranked by ideXlab platform

Mariosnikos Psychogios - One of the best experts on this subject based on the ideXlab platform.

  • Carotid Artery Flow as determined by real time phase contrast Flow mri and neurovascular ultrasound a comparative study of healthy subjects
    European Journal of Radiology, 2018
    Co-Authors: Ilko Maier, Sabine Hofer, Arun A Joseph, Dietmar K Merboldt, Zhengguo Tan, Katharina Schregel, Michael Knauth, Mathias Bahr, Mariosnikos Psychogios
    Abstract:

    Abstract Background The assessment of Carotid Artery Flow by neurovascular ultrasound (nvUS) can be complemented by real-time phase-contrast (RT-PC) Flow MRI which apart from quantitative Flow parameters offers velocity distributions across the entire vessel lumen. Materials and methods The feasibility and diagnostic potential of RT-PC Flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC Flow MRI at 40 ms temporal resolution and 0.8 mm in-plane resolution resulted in velocity maps with low phase noise and high spatiotemporal accuracy by exploiting respective advances of a recent nonlinear inverse model-based reconstruction. Peak-systolic velocities (PSV), end-diastolic velocities (EDV), Flow volumes and comprehensive velocity profiles were determined in the common, internal and external Carotid Artery on both sides. Results Flow characteristics such as pulsatility and individual abnormalities shown on nvUS could be reproduced and visualized in detail by RT-PC Flow MRI. PSV to EDV differences revealed good agreement between both techniques, mean PSV and EDV were significantly lower and Flow volumes were higher for MRI. Conclusion Our findings suggest that RT-PC Flow MRI adds to clinical diagnostics, e.g. by alterations of dynamic velocity distributions in patients with Carotid stenosis. Lower PSV and EDV values than for nvUS mainly reflect the longer MRI acquisition time which attenuates short peak velocities, while higher Flow volumes benefit from a proper assessment of the true vessel lumen.

  • abstract tp201 Carotid Artery Flow as determined by real time phase contrast Flow mri and neurovascular ultrasound a comparative study of healthy subjects
    Stroke, 2018
    Co-Authors: Ilko Maier, Sabine Hofer, Arun A Joseph, Zhengguo Tan, Katharina Schregel, Michael Knauth, Mathias Bahr, Mariosnikos Psychogios, Klausdietmar Merboldt, Jan Liman
    Abstract:

    Background: The assessment of Carotid Artery Flow by neurovascular ultrasound (nvUS) may be complemented by real-time phase-contrast (RT-PC) Flow MRI which apart from quantitative Flow parameters o...

Ilko Maier - One of the best experts on this subject based on the ideXlab platform.

  • Carotid Artery Flow as determined by real time phase contrast Flow mri and neurovascular ultrasound a comparative study of healthy subjects
    European Journal of Radiology, 2018
    Co-Authors: Ilko Maier, Sabine Hofer, Arun A Joseph, Dietmar K Merboldt, Zhengguo Tan, Katharina Schregel, Michael Knauth, Mathias Bahr, Mariosnikos Psychogios
    Abstract:

    Abstract Background The assessment of Carotid Artery Flow by neurovascular ultrasound (nvUS) can be complemented by real-time phase-contrast (RT-PC) Flow MRI which apart from quantitative Flow parameters offers velocity distributions across the entire vessel lumen. Materials and methods The feasibility and diagnostic potential of RT-PC Flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC Flow MRI at 40 ms temporal resolution and 0.8 mm in-plane resolution resulted in velocity maps with low phase noise and high spatiotemporal accuracy by exploiting respective advances of a recent nonlinear inverse model-based reconstruction. Peak-systolic velocities (PSV), end-diastolic velocities (EDV), Flow volumes and comprehensive velocity profiles were determined in the common, internal and external Carotid Artery on both sides. Results Flow characteristics such as pulsatility and individual abnormalities shown on nvUS could be reproduced and visualized in detail by RT-PC Flow MRI. PSV to EDV differences revealed good agreement between both techniques, mean PSV and EDV were significantly lower and Flow volumes were higher for MRI. Conclusion Our findings suggest that RT-PC Flow MRI adds to clinical diagnostics, e.g. by alterations of dynamic velocity distributions in patients with Carotid stenosis. Lower PSV and EDV values than for nvUS mainly reflect the longer MRI acquisition time which attenuates short peak velocities, while higher Flow volumes benefit from a proper assessment of the true vessel lumen.

  • abstract tp201 Carotid Artery Flow as determined by real time phase contrast Flow mri and neurovascular ultrasound a comparative study of healthy subjects
    Stroke, 2018
    Co-Authors: Ilko Maier, Sabine Hofer, Arun A Joseph, Zhengguo Tan, Katharina Schregel, Michael Knauth, Mathias Bahr, Mariosnikos Psychogios, Klausdietmar Merboldt, Jan Liman
    Abstract:

    Background: The assessment of Carotid Artery Flow by neurovascular ultrasound (nvUS) may be complemented by real-time phase-contrast (RT-PC) Flow MRI which apart from quantitative Flow parameters o...

Katharina Schregel - One of the best experts on this subject based on the ideXlab platform.

  • Carotid Artery Flow as determined by real time phase contrast Flow mri and neurovascular ultrasound a comparative study of healthy subjects
    European Journal of Radiology, 2018
    Co-Authors: Ilko Maier, Sabine Hofer, Arun A Joseph, Dietmar K Merboldt, Zhengguo Tan, Katharina Schregel, Michael Knauth, Mathias Bahr, Mariosnikos Psychogios
    Abstract:

    Abstract Background The assessment of Carotid Artery Flow by neurovascular ultrasound (nvUS) can be complemented by real-time phase-contrast (RT-PC) Flow MRI which apart from quantitative Flow parameters offers velocity distributions across the entire vessel lumen. Materials and methods The feasibility and diagnostic potential of RT-PC Flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC Flow MRI at 40 ms temporal resolution and 0.8 mm in-plane resolution resulted in velocity maps with low phase noise and high spatiotemporal accuracy by exploiting respective advances of a recent nonlinear inverse model-based reconstruction. Peak-systolic velocities (PSV), end-diastolic velocities (EDV), Flow volumes and comprehensive velocity profiles were determined in the common, internal and external Carotid Artery on both sides. Results Flow characteristics such as pulsatility and individual abnormalities shown on nvUS could be reproduced and visualized in detail by RT-PC Flow MRI. PSV to EDV differences revealed good agreement between both techniques, mean PSV and EDV were significantly lower and Flow volumes were higher for MRI. Conclusion Our findings suggest that RT-PC Flow MRI adds to clinical diagnostics, e.g. by alterations of dynamic velocity distributions in patients with Carotid stenosis. Lower PSV and EDV values than for nvUS mainly reflect the longer MRI acquisition time which attenuates short peak velocities, while higher Flow volumes benefit from a proper assessment of the true vessel lumen.

  • abstract tp201 Carotid Artery Flow as determined by real time phase contrast Flow mri and neurovascular ultrasound a comparative study of healthy subjects
    Stroke, 2018
    Co-Authors: Ilko Maier, Sabine Hofer, Arun A Joseph, Zhengguo Tan, Katharina Schregel, Michael Knauth, Mathias Bahr, Mariosnikos Psychogios, Klausdietmar Merboldt, Jan Liman
    Abstract:

    Background: The assessment of Carotid Artery Flow by neurovascular ultrasound (nvUS) may be complemented by real-time phase-contrast (RT-PC) Flow MRI which apart from quantitative Flow parameters o...

Jan Liman - One of the best experts on this subject based on the ideXlab platform.

Enrique Criado - One of the best experts on this subject based on the ideXlab platform.

  • transcervical Carotid stenting with Carotid Artery Flow reversal 3 year follow up of 103 stents
    Journal of Vascular Surgery, 2007
    Co-Authors: Enrique Criado, Juan Fontcuberta, Antonio Orgaz, Angel Flores, Manuel Doblas
    Abstract:

    Objective This study evaluated the perioperative and 3-year follow-up results of 103 consecutive Carotid Artery stenting (CAS) procedures done with a transcervical approach using Carotid Flow reversal for cerebral protection that were performed over a 28-month period in 97 patients. Methods The mean age of these patients was 72 years, and 82 (80%) were men. Mean preoperative internal Carotid Artery (ICA) peak systolic velocity was 314 cm/s, 36% of treated hemispheres were symptomatic, and 42% of patients had neurologic symptoms for >6 months. Ten patients (10%) had contralateral ICA occlusion, six (6%) had recurrent Carotid stenosis, and two (2%) had previous neck radiation. Local anesthesia was used in 72 (70%) cases and general in 31 (30%). Predilatation was used in 34 cases (33%), and closed-cell self-expanding stents were deployed and postdilated in all cases. Results Technical success was achieved in 100 cases (97%). No major strokes or deaths occurred. One ipsilateral transient ischemic attack (1%), one contralateral transient ischemic attack (1%), and two minor strokes (2%) occurred. There were two wound complications (2%) and one major arterial complication (1%). Mean operative time was 69 minutes, and mean Carotid Flow reversal time was 21 minutes. Three awake patients (4%) did not tolerate Carotid Flow reversal. Hypotension/bradycardia occurred in 24 cases (23%). No electrocardiographic myocardial infarctions were diagnosed. At 40 months of follow-up, the stent patency rate on an intention-to-treat basis was 95%, and the stroke-free survival was 91%. Conclusions Transcervical CAS with Carotid Flow reversal can be done with a high rate of technical success, a negligible rate of major adverse events, and an excellent 3-year stroke-free survival and stent patency rate. These results compare favorably with those of recently published prospective studies using distal filter protection during CAS.

  • transcervical Carotid stenting with internal Carotid Artery Flow reversal feasibility and preliminary results
    Journal of Vascular Surgery, 2004
    Co-Authors: Enrique Criado, Manuel Doblas, Juan Fontcuberta, Antonio Orgaz, Angel Flores, Paloma Lopez, Philipp L Wall, Antonios P Gasparis, Jaime Strachan, John J Ricotta
    Abstract:

    Objective Transfemoral Carotid Artery stenting (CAS), with or without distal protection, is associated with risk for cerebral and peripheral embolism and access site complications. To establish cerebral protection before crossing the Carotid lesion and to avert transfemoral access complications, the present study was undertaken to evaluate a transcervical approach for CAS with Carotid Flow reversal for cerebral protection. Methods Fifty patients underwent CAS through a transcervical approach. All patients with symptoms had greater than 60% internal Carotid Artery (ICA) stenosis, and all patients without symptoms had greater than 80% ICA stenosis. Twenty-one patients (42%) had symptomatic disease or ipsilateral stroke, and 8 patients (16%) had contralateral stroke. Four patients (8%) had recurrent stenosis, 7 patients (14%) had contralateral ICA occlusion, and 1 patient (2%) had undergone previous neck radiation. Twenty-seven procedures (54%) were performed with local anesthesia, and 23 (46%) with general anesthesia. Using a cervical cutdown, Flow was reversed in the ICA by occluding the common Carotid Artery and establishing a Carotid–jugular vein fistula. Pre-dilation was selective, and 8-mm to 10-mm self-expanding stents were deployed and post-dilated with 5-mm to 6-mm balloons in all cases. Results The procedure was technically successful in all patients, without significant residual stenoses. No strokes or deaths occurred. There was 1 wound complication (2%). All patients were discharged within 2 days of surgery. Mean Flow reversal time was 21.4 minutes (range, 9-50 minutes). Carotid Flow reversal was not tolerated in 2 patients (4%). Early in the experience, Carotid Flow reversal was not possible in 1 patient, and there were 1 major and 3 minor common Carotid Artery dissections, which resolved after stent placement. One intraoperative transient ischemic attack (2%) occurred in 1 patient in whom Carotid Flow was not reversed, and 1 patient with a contralateral ICA occlusion had a contralateral transient ischemic attack. At 1 to 12 months of follow-up, all patients remained asymptomatic, and all but 1 stent remained patent. Conclusion Transcervical CAS with Carotid Flow reversal is feasible and safe. It can be done with the patient under local anesthesia, averts the complications of the transfemoral approach, and eliminates the increased complexity and cost of cerebral protection devices. Transcervical CAS is feasible when the transfemoral route is impossible or contraindicated, and may be the procedure of choice in a subset of patients in whom Carotid stenting is indicated.

  • Carotid angioplasty with internal Carotid Artery Flow reversal is well tolerated in the awake patient.
    Journal of Vascular Surgery, 2004
    Co-Authors: Enrique Criado, Manuel Doblas, Juan Fontcuberta, Antonio Orgaz, Angel Flores, Paloma Lopez, L. Philipp Wall
    Abstract:

    Abstract Objective The purpose of this study was to evaluate the neurologic tolerance and changes in ipsilateral hemispheric oxygen saturation during transcervical Carotid Artery stenting with internal Carotid Artery (ICA) Flow reversal for embolic protection. Patients and methods This was a prospective study of 10 patients (mean age 68 years) undergoing transcervical Carotid angioplasty and stenting. All ICA stenoses were greater that 70%. Seven patients had an ipsilateral hemispheric stroke (3) or transient ischemic attack (4), two patients had a contralateral stroke, and one patient was asymptomatic. Nine procedures were done under local anesthesia. Cerebral protection was established through a cervical common Carotid (CCA) cutdown to create an external fistula between the ICA and the internal jugular vein with temporally CCA occlusion. Venous oxygen saturation (SVO2) was continuously monitored through a catheter placed in the distal internal jugular vein. Mental status and motor-sensory changes were categorized and assessed throughout and after the procedure. Results All procedures were technically successful without significant residual stenosis. Mean ICA Flow reversal time was 22 minutes (range, 15 to 32). Common Carotid Artery (CCA) occlusion produced a slight (SVO2 = 72.6%+/-9.4) but significant decrease (P = .012) in SVO2, compared with baseline (SVO2 = 77% +/-10.5). During ICA Flow reversal (SVO2 = 72.4% +/-10.1) cerebral oxygen saturation did not change compared with CCA occlusion alone (P = .85). Transient balloon occlusion during angioplasty of the ICA (SVO2 = 64.6%+/-12.9) produced a significant decrease in cerebral SVO2 compared with CCA occlusion (P = .015) and compared with CCA occlusion with ICA Flow reversal (P = .018). No mental status changes or ipsilateral hemispheric focal symptoms occurred during CCA occlusion with ICA Flow reversal. One patient with contralateral ICA occlusion sustained brief upper extremity weakness related to the contralateral hemisphere. Five patients sustained a vasovagal response during balloon dilatation, four did not require treatment, and one had asystole requiring atropine injection. Mean SVO2 saturation was not different in these five patients compared with the five who did not sustain a vasovagal response. No deaths or neurologic deficits occurred within 30 days after the procedure. Conclusions Our data suggest that transcervical Carotid angioplasty and stenting with ICA Flow reversal is well tolerated in the awake patient, even in the presence of symptomatic Carotid Artery disease. Cerebral oxygenation during ICA Flow reversal is comparable to that during CCA occlusion. ICA angioplasty balloon inflation produces a decrease in cerebral SVO2 significantly greater than that occurring during ICA Flow reversal.