Time‐resolved 3D MR velocity mapping at 3T: Improved navigator‐gated assessment of vascular anatomy and blood flow

Markl, Michael; Harloff, Andreas; Bley, Thorsten Alexander; Zaitsev, Maxim; Jung, Bernd; Weigang, Ernst; Langer, Mathias; Hennig, Jürgen; Frydrychowicz, Alex

doi:10.1002/jmri.20871

Cited by 350 publications

(355 citation statements)

References 30 publications

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“…Prospectively ECG‐gated time‐resolved 3D phase‐contrast MRI with 3‐directional velocity encoding (4D flow MRI) was used to measure in vivo 3D blood flow velocity with full volumetric coverage of the LV. The 4D flow MRI data were acquired during free breathing using navigator gating of the diaphragm motion 12. Further 4D flow MRI pulse sequence parameters were as follows: flip angle 7°, spatial resolution 2.5×2.9×3.0 mm, temporal resolution 38.4 ms, imaging acceleration using the Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) technique with a reduction factor of R =2, total acquisition time of 10 to 15 minutes depending on heart rate and navigator efficiency, velocity sensitivity 150 cm/s.…”

Section: Methodsmentioning

confidence: 99%

Integrated Regional Cardiac Hemodynamic Imaging and RNA Sequencing Reveal Corresponding Heterogeneity of Ventricular Wall Shear Stress and Endocardial Transcriptome

McCormick

Manduchi

Witschey

et al. 2016

JAHA

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BackgroundUnlike arteries, in which regionally distinct hemodynamics are associated with phenotypic heterogeneity, the relationships between endocardial endothelial cell phenotype and intraventricular flow remain largely unexplored. We investigated regional differences in left ventricular wall shear stress and their association with endocardial endothelial cell gene expression.Methods and ResultsLocal wall shear stress was calculated from 4‐dimensional flow magnetic resonance imaging in 3 distinct regions of human (n=8) and pig (n=5) left ventricle: base, adjacent to the outflow tract; midventricle; and apex. In both species, wall shear stress values were significantly lower in the apex and midventricle relative to the base; oscillatory shear index was elevated in the apex. RNA sequencing of the endocardial endothelial cell transcriptome in pig left ventricle (n=8) at a false discovery rate ≤10% identified 1051 genes differentially expressed between the base and the apex and 327 between the base and the midventricle; no differentially expressed genes were detected at this false discovery rate between the apex and the midventricle. Enrichment analyses identified apical upregulation of genes associated with translation initiation including mammalian target of rapamycin, and eukaryotic initiation factor 2 signaling. Genes of mitochondrial dysfunction and oxidative phosphorylation were also consistently upregulated in the left ventricular apex, as were tissue factor pathway inhibitor (mean 50‐fold) and prostacyclin synthase (5‐fold)—genes prominently associated with antithrombotic protection.ConclusionsWe report the first spatiotemporal measurements of wall shear stress within the left ventricle and linked regional hemodynamics to heterogeneity in ventricular endothelial gene expression, most notably to translation initiation and anticoagulation properties in the left ventricular apex, in which oscillatory shear index is increased and wall shear stress is decreased.

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Section: Methodsmentioning

confidence: 99%

Integrated Regional Cardiac Hemodynamic Imaging and RNA Sequencing Reveal Corresponding Heterogeneity of Ventricular Wall Shear Stress and Endocardial Transcriptome

McCormick

Manduchi

Witschey

et al. 2016

JAHA

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“…Data were acquired using an eight-channel body phased-array coil and a radio frequency (RF) spoiled gradient-echo sequence with interleaved three-directional velocity encoding (bandwidth ϭ Ϯ480 Hz/pixel, flip angle ϭ 15°, TE/TR ϭ 3.67 msec/6.1 msec, venc ϭ 150 cm/second, spatial resolution ϭ (2.71-2.93 ϫ 1.58 -1.69 ϫ 2.60 -3.0) mm 3 , and temporal resolution ϭ 48.8 msec, allowing for 11-15 time frames/cardiac cycle. All measurements were prospectively gated to the electrocardiogram (ECG) cycle and utilized an adaptive navigator gating to enable free breathing, as described previously (27). The study was approved by the local ethics committee and written informed consent was obtained from all individuals prior to participation in the study.…”

Section: Mrimentioning

confidence: 99%

Three‐dimensional analysis of segmental wall shear stress in the aorta by flow‐sensitive four‐dimensional‐MRI

Frydrychowicz

Stalder

Russe

et al. 2009

Magnetic Resonance Imaging

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161

138

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Purpose:To assess the distribution and regional differences of flow and vessel wall parameters such as wall shear stress (WSS) and oscillatory shear index (OSI) in the entire thoracic aorta. Materials and Methods:Thirty-one healthy volunteers (mean age ϭ 23.7 Ϯ 3.3 years) were examined by flow-sensitive four-dimensional (4D)-MRI at 3T. For eight retrospectively positioned 2D analysis planes distributed along the thoracic aorta, flow parameters and vectorial WSS and OSI were assessed in 12 segments along the vascular circumference. Conclusion:The normal distribution of vectorial WSS and OSI in the entire thoracic aorta derived from flow-sensitive 4D-MRI data provides a reference constituting an important perquisite for the examination of patients with aortic disease. Marked regional differences in absolute WSS and OSI may help explaining why atherosclerotic lesions predominantly develop and progress at specific locations in the aorta. COMPLEX VASCULAR GEOMETRY AND PULSATILE FLOW in the human arterial system lead to regionally different flow characteristics and thus spatial and temporal changes in shear forces acting on the vessel wall. These forces can be characterized by wall shear stress (WSS) or oscillatory shear index (OSI) that play an important role in flow-mediated atherogenesis and arterial remodeling (1-3). While WSS values reported in the literature typically reflect the time-averaged shear forces acting on the vessel wall, OSI describes the existence and magnitude of WSS changes over the cardiac cycle. Recent reports stressed the importance of WSS and OSI with respect to the formation and stability of atherosclerotic plaques (4). A number of studies have shown that low WSS and high OSI represent sensitive markers for formation of plaques in the aorta, carotid, or coronary arteries (5,6). Particularly, the assessment of both WSS and OSI can help to determine the complexity of the lesions. A recent study with animal models and deliberately altered flow characteristics in the carotid arteries demonstrated the close correlation of low WSS with the development of vulnerable high-risk plaques whereas high OSI induce stable lesions (4). In addition, the effects of selected pathologies on regionally-varying WSS and OSI values have been reported (7,8).Among other methods, MRI is a feasible and extensively validated technique to derive quantitative flow information from arterial vessels (9 -12). Due to its intrinsic sensitivity to flow and the possibility to acquire true time-resolved three-dimensional (3D) data, in vivo analyses of blood-flow and derived vessel wall parameters are promising. However, earlier reports on MRbased analysis of aortic hemodynamics were either based on incomplete vascular coverage and separately acquired 2D slices (13-17), a combination of MR mea-

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“…Recently, improved time-resolved (CINE) 3D PC MRI techniques using electrocardiography (ECG) gating and advanced navigator respiration control (flow-sensitive four-dimensional [4D] MRI) have been successfully applied for the analysis of pulsatile 3D blood flow in the aorta (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). Such techniques offer the opportunity for the detailed analysis of pulsatile 3D blood flow but require scan times up to 20 min.…”

Section: Contrast-enhanced (Ce) Mr Angiography (Mra) Is An Establishementioning

confidence: 99%

“…Such techniques offer the opportunity for the detailed analysis of pulsatile 3D blood flow but require scan times up to 20 min. We previously reported an approach to derive 3D angiographic information (3D PC-MRA) from flow-sensitive 4D MRI (24,25). We showed that it was possible to exploit the information in the acquired flow-sensitive 4D data to derive angiographic information without performing additional MRA measurements.…”

Section: Contrast-enhanced (Ce) Mr Angiography (Mra) Is An Establishementioning

confidence: 99%

“…Additionally, flow-sensitive 4D MRI in a sagittal oblique 3D slab covering the entire thoracic aorta was performed for all 30 volunteers, using a respiration-controlled and ECG-gated radiofrequency-spoiled gradient echo sequence as described in Markl et al (24). Pulse sequence parameters for both measurements are summarized in Table 1.…”

Section: Study Population and Mrimentioning

confidence: 99%

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4D phase contrast MRI at 3 T: Effect of standard and blood‐pool contrast agents on SNR, PC‐MRA, and blood flow visualization

Bock

Frydrychowicz

Stalder

et al. 2009

Magnetic Resonance in Med

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113

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Time-resolved phase contrast (PC) MRI with velocity encoding in three directions (flow-sensitive four-dimensional MRI) can be employed to assess three-dimensional blood flow in the entire aortic lumen within a single measurement. These data can be used not only for the visualization of blood flow but also to derive additional information on vascular geometry with three-dimensional PC MR angiography (MRA). As PC-MRA is sensitive to available signal-to-noise ratio, standard and novel blood pool contrast agents may help to enhance PC-MRA image quality. In a group of 30 healthy volunteers, the influence of different contrast agents on vascular signalto-noise ratio, PC-MRA quality, and subsequent three-dimensional stream-line visualization in the thoracic aorta was determined. Flow-sensitive four-dimensional MRI data acquired with contrast agent provided significantly improved signal-to-noise ratio in magnitude data and noise reduction in velocity data compared to measurements without contrast media. The agreement of three-dimensional PC-MRA with reference standard contrast-enhanced MRA was good for both contrast agents, with improved PC-MRA performance for blood pool contrast agent, particularly for the smaller supraaortic branches. While most clinical applications of MRA rely on the application of Gadolinium (Gd) contrast agent (CA), three-dimensional (3D) phase contrast (PC)-MRA based on velocity-encoded 3D MRI with encoding in three directions has proven to be a useful alternative (8-11). PC-MRA can provide detailed information on vascular geometry and may offer additional information on flow direction. However, most PC-MRA implementations used nongated data acquisition, which can result in artifacts for pulsatile blood flow. Further drawbacks of the PC-MRA method are long scan times and lack of respiration control, which limited most applications of 3D PC-MRA to static regions with low pulsatile flow such as the cranial vessels (12,13).Recently, improved time-resolved (CINE) 3D PC MRI techniques using electrocardiography (ECG) gating and advanced navigator respiration control (flow-sensitive four-dimensional [4D] MRI) have been successfully applied for the analysis of pulsatile 3D blood flow in the aorta (14-24). Such techniques offer the opportunity for the detailed analysis of pulsatile 3D blood flow but require scan times up to 20 min. We previously reported an approach to derive 3D angiographic information (3D PC-MRA) from flow-sensitive 4D MRI (24,25). We showed that it was possible to exploit the information in the acquired flow-sensitive 4D data to derive angiographic information without performing additional MRA measurements. Although the derived 3D PC-MRA does not provide the same detailed depiction of anatomy and morphology compared to CE-MRA, it can improve considerably the presentation of the results by combining 3D visualization of anatomy and flow for large vascular geometries such as the thoracic aorta.Based on this strategy, an improved data processing workflow including noise masking was impleme...

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Time‐resolved 3D MR velocity mapping at 3T: Improved navigator‐gated assessment of vascular anatomy and blood flow

Cited by 350 publications

References 30 publications

Integrated Regional Cardiac Hemodynamic Imaging and RNA Sequencing Reveal Corresponding Heterogeneity of Ventricular Wall Shear Stress and Endocardial Transcriptome

Integrated Regional Cardiac Hemodynamic Imaging and RNA Sequencing Reveal Corresponding Heterogeneity of Ventricular Wall Shear Stress and Endocardial Transcriptome

Three‐dimensional analysis of segmental wall shear stress in the aorta by flow‐sensitive four‐dimensional‐MRI

4D phase contrast MRI at 3 T: Effect of standard and blood‐pool contrast agents on SNR, PC‐MRA, and blood flow visualization

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