Search results for "DOPPLER"

Successful transcatheter aortic valve-in-valve implantation in a patient having a chronic type A aortic dissection

2017

Normal Doppler Reference Values of the Pericallosal Artery

2015

Purpose: To provide the normal reference values of the Doppler flow of the pericallosal artery in relation to gestational age from 18 to 41 weeks of gestation. Materials and Methods: The pericallosal artery (PCA) was studied in 466 normal pregnancies. The pulsed Doppler evaluation of the pericallosal artery was done in A3 and A4 segments, and records from PI, RI and Vmax were studied. Results: The resistance index of the pericallosal artery in A3 / A4 segments exhibits a plateau from 18 to 31 weeks of gestation. After 31 weeks, a marked decrease becomes apparent. The pulsatility index of the pericallosal artery in A3 / A4 segments shows a plateau until 36 weeks of gestation. During the fina…

Recommendations for Multimodal Noninvasive and Invasive Screening for Detection of Extracranial Venous Abnormalities Indicative of Chronic Cerebrospi…

2014

Under the auspices of the International Society for Neurovascular Disease (ISNVD), four expert panel committees were created from the ISNVD membership between 2011 and 2012 to determine and standardize noninvasive and invasive imaging protocols for detection of extracranial venous abnormalities indicative of chronic cerebrospinal venous insufficiency (CCSVI). The committees created working groups on color Doppler ultrasound (US), magnetic resonance (MR) imaging, catheter venography (CV), and intravascular US. Each group organized a workshop focused on its assigned imaging modality. Non-ISNVD members from other societies were invited to contribute to the various workshops. More than 60 neuro…

Ethylene-vinyl alcohol copolymer (Onyx®) transarterial embolization for post-traumatic high-flow priapism

2016

International audience; We report a case of high-flow priapism treated successfully with superselective embolization of the cavernous artery. A 16-year-old male developed post-traumatic priapism subsequent to a fall causing blunt perineal trauma. He presented to our hospital four days after trauma. Immediately after the injury, he suffered painless sustained incomplete erection. High-flow priapism was diagnosed on the basis of color doppler ultrasonography findings. Computed tomography scan showed a high-flow arterio-venous fistula with feeders from branches of the right internal iliac artery. Selective arteriography of the right internal pudendal artery demonstrated an arterio-cavernous fi…

Renal resistive index: Beyond the hemodynamics

2020

We read with great interest the original article entitled “Prognostic significance of the renal resistive index in the primary prevention of type II diabetes” by Delsart et al1 In this issue of The Journal, the authors interestingly underlined the prognostic value of renal resistive index (RRI) in diabetic subjects and its role as an independent predictor of a first cardiovascular or renal event. Similar conclusions were previously obtained by others in different subsets of patients (hypertension, chronic kidney disease, or heart failure), in which intrarenal hemodynamic alterations showed to be independent predictors of cardiovascular events. It is likely that the mechanisms underlying ren…

Internal jugular vein entrapment in a multiple sclerosis patient.

2012

We describe a multiple sclerosis patient presenting with compression of the internal jugular vein caused by aberrant omohyoid muscle. Previously this patient underwent balloon angioplasty of the same internal jugular vein. Ten months after this endovascular procedure, Doppler sonography revealed totally collapsed middle part of the treated vein with no outflow detected. Still, the vein widened and the flow was restored when the patient’s mouth opened. Thus, the abnormality was likely to be caused by muscular compression. Surgical exploration confirmed that an atypical omohyoid muscle was squeezing the vein. Consequently, pathological muscle was transected. Sonographic control three weeks af…

Dopplersonographische Blutflußmessung der A. umbilicalis: Ist ein Screening sinnvoll?

1989

Imaging photoplethysmography for assessment of chronic pain patients

2019

In present pilot study application of multi-spectral imaging photoplethysmography for assessment of chronic pain patients during topical skin heating test was proposed. Photoplethysmography signal was recorded at 420nm, 530nm and 810nm illumination from the skin and corresponding perfusion indexes and perfusion maps were calculated. The novel parameter-PPGflare index was introduced and compared in neuropathic patients and healthy volunteers. Preliminary results suggest that neuropathic patients exhibited significantly lower PPGflare index, and that local heating substantially change PPG waveform at heat exposed skin region. Present study emphasizes advantages of imaging photoplethysmography…

Temporal and Spatial Evolution of Cortical Blood Flow in the Penumbra of Venous Infarcts

2001

A cortical venous infarction model has been evaluated regarding the temporal and spatial evolution of regional flow reduction. Two cortical veins were occluded photochemically with rose bengal and fiberoptic illumination. Seven rats served to demonstrate effects on regional cortical blood flow using laser Doppler scanning. After two-vein occlusion, there was a widespread reduction of flow that gradually deteriorated after vein occlusion when regional cortical flow in a 3.5 x 7.0 mm window: after 15 min it had decreased to 57.8% ± 8.0%, and after 75 min it was 34.3% ± 5.4%. Infarct volumes as determined in 10 rats 5 days after two-vein occlusion had an average size of 3.6 ± 0.7 mm3. The data…

Modelling of the Ischemic Penumbra

1999

What happens to the ischemic penumbra – defined as a territory of critically reduced blood flow in the close neighborhood of an ischemic core – determines outcome after stroke. Currently the pathophysiology of the penumbra is studied predominantly in rat models with occlusion of the middle cerebral artery. Here we propose two other rat models with distinct advantages. One produces a large territory of critical flow reduction in the cortex of one hemisphere without presence of an infarct core: this model is suited to study mediator mechanisms that may transform the penumbra into necrotic tissue. It is produced by occluding one carotid artery and in addition reducing arterial pressure to 50mm…