نتایج جستجو برای: velocity ratio

تعداد نتایج: 630497  

Journal: :Journal of magnetic resonance imaging : JMRI 2009
Marijn P Rolf Mark B M Hofman Joost P A Kuijer Albert C van Rossum Rob M Heethaar

PURPOSE To test whether a 3D imaging sequence with phase contrast (PC) velocity encoding based on steady-state free precession (SSFP) improves 3D velocity quantification in the heart compared to the currently available gradient echo (GE) approach. MATERIALS AND METHODS The 3D PC-SSFP sequence with 1D velocity encoding was compared at the mitral valve in 12 healthy subjects with 3D PC-GE at 1....

Journal: :Journal of the American College of Cardiology 1993
E O Ofili M J Kern A J Labovitz J A St Vrain J Segal F V Aguirre R Castello

OBJECTIVES This study was designed to assess whether the spectral waveform of coronary velocity on Doppler study is characteristically altered in the presence of significant stenosis with normalization of the spectral waveform after relief of endolumen obstruction. BACKGROUND Although coronary flow reserve determinations have provided physiologic information complementary to the angiographic ...

Journal: :European journal of echocardiography : the journal of the Working Group on Echocardiography of the European Society of Cardiology 2007
Jacqueline E A K Bamfo Nikos A Kametas Kypros H Nicolaides John B Chambers

AIMS The aim of this study was to evaluate left ventricular (LV) function during normal pregnancy and investigate the effect of maternal factors. Little information about LV diastolic and long-axis systolic function in normal pregnancy exists. METHODS AND RESULTS Two hundred and twenty eight Doppler echocardiography and DTI studies of the mitral annulus were performed in 63 normal pregnant wo...

2002
J. P. Narayan

This paper presents the H/V ratio peak amplitude and frequency, their correlation with the site frequency and amplification factor, and limitations. The basin-edge and flat-layer models with different types of soils in the surficial layer were simulated using 2.5D (two and half dimensional) modeling. The effects of sediment bedrock velocity contrast on the H/V ratio peak frequency and amplitude...

Journal: :iranian journal of medical sciences 0
n.m. noori kambiz keshavarz

background: beta-thalassemia major is a severe and lethal hemolytic anemia. regular transfusion is necessary for avoidance of its complications but it may end to cardiac involvement secondary to iron overload. angiotensin converting enzyme inhibitors (aceis) are useful medications even in early stages of heart failure. we studied the effects of two common aceis on improvement of heart function ...

Journal: :Stroke 2004
Kozue Saito Kazumi Kimura Kazuyuki Nagatsuka Keiko Nagano Kazuo Minematsu Satoshi Ueno Hiroaki Naritomi

BACKGROUND AND PURPOSE To establish the diagnostic criteria for the site of occlusion in the vertebral arteries (VAs) using duplex color-coded ultrasonography. METHODS In 128 consecutive patients who underwent conventional cerebral angiography, we prospectively measured the diameter, mean flow velocity (MV), peak systolic flow velocity, and end-diastolic flow velocity of both VAs. The diamete...

Journal: :Neuro-oncology 2013
Johan Pallud Marie Blonski Emmanuel Mandonnet Etienne Audureau Denys Fontaine Nader Sanai Luc Bauchet Philippe Peruzzi Marc Frénay Philippe Colin Rémy Guillevin Valérie Bernier Marie-Hélène Baron Jacques Guyotat Hugues Duffau Luc Taillandier Laurent Capelle

BACKGROUND Supratentorial diffuse low-grade gliomas present a slow macroscopic tumor growth that can be quantified through the measurement of their velocity of diametric expansion. We assessed whether spontaneous velocity of diametric expansion can predict long-term outcomes as a categorical variable and as a continuous predictor. METHODS A total of 407 adult patients with newly diagnosed sup...

Journal: :Journal of the American College of Cardiology 1998
L Thomas E Foster N B Schiller

OBJECTIVES Mitral regurgitation (MR) is a common echocardiographic finding; however, there is no simple accurate method for quantification. The aim of this study was to develop an easily measured screening variable for hemodynamically significant MR. BACKGROUND The added regurgitant volume in MR increases the left atrial to left ventricular gradient, which then increases the peak mitral inflo...

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