Human abdominal aorta: comparative measurements of blood flow with MR imaging and multigated Doppler US.

Maier, Stephan E.; Meier, D.; Boesiger, Peter; Moser, Urs; Vieli, A.

doi:10.1148/radiology.171.2.2649924

Cited by 129 publications

(60 citation statements)

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“…The reverse-flow patterns that were observed along the posterior wall of the infrarenal aorta and opposite the celiac and superior mesenteric arteries at rest were consistent with previous computational (35), in vitro (15,23), and in vivo (10,17,28,32) studies and correlated to areas of localized sudanophilia (2). In computational simulations of blood flow in an idealized abdominal aortic geometry, Taylor et al (35) noted that the velocity field in the infrarenal aorta was directed toward the anterior wall and that a recirculation region existed along the posterior wall at the level of the renal arteries.…”

Section: Discussionsupporting

confidence: 87%

Abdominal aortic hemodynamics in young healthy adults at rest and during lower limb exercise: quantification using image-based computer modeling

Tang

Cheng²,

Draney³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

125

109

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. Abdominal aortic hemodynamics in young healthy adults at rest and during lower limb exercise: quantification using image-based computer modeling. Am J Physiol Heart Circ Physiol 291: H668 -H676, 2006. First published April 7, 2006 doi:10.1152/ajpheart.01301.2005.-Localization of atherosclerotic lesions in the abdominal aorta has been previously correlated to areas of adverse hemodynamic conditions, such as flow recirculation, low mean wall shear stress, and high temporal oscillations in shear. Along with its many systemic benefits, exercise is also proposed to have local benefits in the vasculature via the alteration of these regional flow patterns. In this work, subject-specific models of the human abdominal aorta were constructed from magnetic resonance angiograms of five young, healthy subjects, and computer simulations were performed under resting and exercise (50% increase in resting heart rate) pulsatile flow conditions. Velocity fields and spatial variations in mean wall shear stress (WSS) and oscillatory shear index (OSI) are presented. When averaged over all subjects, WSS increased from 4.8 Ϯ 0.6 to 31.6 Ϯ 5.7 dyn/cm 2 and OSI decreased from 0.22 Ϯ 0.03 to 0.03 Ϯ 0.02 in the infrarenal aorta between rest and exercise. WSS significantly increased, whereas OSI decreased between rest and exercise at the supraceliac, infrarenal, and suprabifurcation levels, and significant differences in WSS were found between anterior and posterior sections. These results support the hypothesis that exercise provides localized benefits to the cardiovascular system through acute mechanical stimuli that trigger longer-term biological processes leading to protection against the development or progression of atherosclerosis. atherosclerosis; shear stress; magnetic resonance imaging; finite element analysis ADVERSE HEMODYNAMIC conditions, such as complex, recirculating flow, low mean wall shear stress, high spatial gradients in shear stress, and high particle residence times, are hypothesized to contribute to the localization of atherosclerotic plaque throughout the vasculature. In the abdominal aorta, a correlation between atherosclerosis and areas of low wall shear stress has been elucidated with prior autopsy (2,7,27,31,39) and experimental studies (5,16,19,20,22,32). Specifically, Cornhill et al. (2) observed a high probability of occurrence of sudanophilic lesions along the posterior and lateral walls of autopsy specimens obtained from young, healthy males, whereas Roberts et al. (27) and Glagov et al. (21), and in vitro cell culture work has shown that oscillating shear can induce an inflammatory response, including an increase in reactive oxygen species (3,9,29).Conversely, elevated blood flow associated with exercise has been hypothesized to result in hemodynamic conditions that inhibit atherosclerosis, such as unidirectional laminar flow, increased wall shear stress, and enhanced transport of cholesterol from the vessel wall (11,18,32,33). It has been shown in vitro that the vascular endothelium can sense and resp...

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Section: Discussionsupporting

confidence: 87%

Abdominal aortic hemodynamics in young healthy adults at rest and during lower limb exercise: quantification using image-based computer modeling

Tang

Cheng²,

Draney³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

125

109

View full text Add to dashboard Cite

show abstract

“…2 and 3). There have been some reports which described the results of in vivo measurements of blood flow in the lower thoracic aorta carried out by using hot-film anemometry (25), (26) , and MR Imaging and Doppler ultrasound velocimetry (10), (27) . The consensus of these studies is that the flow from the left ventricle never becomes a fully developed Poiseuille flow when it reaches the abdominal aorta.…”

Section: Discussionmentioning

confidence: 99%

Flow Patterns in the Dog Descending Aorta under a Steady Flow Condition Simulating Mid-Systole

Endo

Goldsmith

Karino

2004

JSME Int. J., Ser. C

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Hemodynamic factors are suspected to be involved in the localized pathogenesis and development of atherosclerotic lesions in the human thoracico-abdominal aorta. Hence, we studied the detailed flow patterns and the distributions of fluid velocity and wall shear stress there under the condition of a steady flow using five transparent aortic trees prepared from dogs as models of the human descending aorta and by means of flow visualization and highspeed cinemicrographic techniques. It was found that in all the cases the flow in the descending aorta was not fully developed to the extent to provide a parabolic velocity profile. Flow was disturbed at each junction, and most complex secondary and adverse flows formed at the branching site of the left renal artery adjacent to the lateral and posterior walls of the descending aorta. Furthermore, there was considerable interaction between the secondary and adverse flows formed at the branching sites of the four major arteries that stemmed off the descending aorta.

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“…20 The superiority of magnetic resonance imaging over other imaging modalities is the capability of generating up to three-dimensional velocity profiles that can reflect the dynamics of blood flow more accurately and with quantifiable details. Apart from such localized measurements that can provide interactive visualization in cardiovascular flow, 74 phase contrast MRI has also been utilized in global flow measurements such as determination of flow volumes in arterial structures, and in particular, blood ejection volumes in the ascending aorta 39,40,55 as well as arterial wall shear stress. 50,51,68 It has been widely documented that phase contrast MRI is an established flow-imaging scheme for cardiovascular examination of human subjects and compares well with ultrasound technology.…”

Section: Comparison Of Pc-mri With Ultrasoundmentioning

confidence: 99%

“…50,51,68 It has been widely documented that phase contrast MRI is an established flow-imaging scheme for cardiovascular examination of human subjects and compares well with ultrasound technology. 40 Further development of phase contrast MRI to produce multi-slice cine images involves an electrocardiogram synchronized time-resolved framework to allow assessment of blood-flow characteristics with high spatial and temporal resolution of a cardiovascular region of interest. 30,74 Sometimes there may be poor quality image registration due to poor respiratory control during scanning.…”

Section: Comparison Of Pc-mri With Ultrasoundmentioning

confidence: 99%

Cardiac Flow Analysis Applied to Phase Contrast Magnetic Resonance Imaging of the Heart

et al. 2009

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Abstract-Phase contrast magnetic resonance imaging is performed to produce flow fields of blood in the heart. The aim of this study is to demonstrate the state of change in swirling blood flow within cardiac chambers and to quantify it for clinical analysis. Velocity fields based on the projection of the three dimensional blood flow onto multiple planes are scanned. The flow patterns can be illustrated using streamlines and vector plots to show the blood dynamical behavior at every cardiac phase. Large-scale vortices can be observed in the heart chambers, and we have developed a technique for characterizing their locations and strength. From our results, we are able to acquire an indication of the changes in blood swirls over one cardiac cycle by using temporal vorticity fields of the cardiac flow. This can improve our understanding of blood dynamics within the heart that may have implications in blood circulation efficiency. The results presented in this paper can establish a set of reference data to compare with unusual flow patterns due to cardiac abnormalities. The calibration of other flow-imaging modalities can also be achieved using this well-established velocityencoding standard.

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Human abdominal aorta: comparative measurements of blood flow with MR imaging and multigated Doppler US.

Cited by 129 publications

References 0 publications

Abdominal aortic hemodynamics in young healthy adults at rest and during lower limb exercise: quantification using image-based computer modeling

Abdominal aortic hemodynamics in young healthy adults at rest and during lower limb exercise: quantification using image-based computer modeling

Flow Patterns in the Dog Descending Aorta under a Steady Flow Condition Simulating Mid-Systole

Cardiac Flow Analysis Applied to Phase Contrast Magnetic Resonance Imaging of the Heart

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