scholarly journals Characterization of Blood Flow Changes in Normal and Pathological Aortic Dilation from 4D Flow Magnetic Resonance Imaging

2019 ◽  
Author(s):  
Sophia Houriez-Gombaud-Saintonge ◽  
Ariel Pascaner ◽  
Gilles Soulat ◽  
Umit Gencer ◽  
Thomas Dietenbeck ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Aortic Dilation ◽  
4D Flow ◽  
Flow Changes

scholarly journals The effect of pulmonary blood flow changes on oxygen-enhanced lung magnetic resonance imaging

2012 ◽  
Vol 69 (6) ◽  
pp. 1645-1649 ◽  
Author(s):  
Hye-Jeong Lee ◽  
Jaeseok Park ◽  
Jin Hur ◽  
Young Jin Kim ◽  
Ji Eun Nam ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Pulmonary Blood Flow ◽  
Resonance Imaging ◽  
Flow Changes

Arterial spin labeling blood flow magnetic resonance imaging for the characterization of metastatic renal cell carcinoma1

2005 ◽  
Vol 12 (3) ◽  
pp. 347-357 ◽  
Author(s):  
Cedric De Bazelaire ◽  
Neil M. Rofsky ◽  
Guillaume Duhamel ◽  
M. Dror Michaelson ◽  
Daniel George ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Renal Cell ◽  
Arterial Spin Labeling ◽  
Spin Labeling ◽  
Resonance Imaging

scholarly journals Left and right ventricular hemodynamic forces in healthy volunteers and elite athletes assessed with 4D flow magnetic resonance imaging

2017 ◽  
Vol 312 (2) ◽  
pp. H314-H328 ◽  
Author(s):  
Per M. Arvidsson ◽  
Johannes Töger ◽  
Marcus Carlsson ◽  
Katarina Steding-Ehrenborg ◽  
Gianni Pedrizzetti ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Right Ventricular ◽  
Healthy Subjects ◽  
Elite Athletes ◽  
Left Ventricular ◽  
Resonance Imaging ◽  
4D Flow ◽  
Hemodynamic Forces

Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only left ventricular (LV) forces. Right ventricular (RV) forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify 3D hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. Twenty five controls, 14 elite endurance athletes, and 2 patients with LV dyssynchrony were included. 4D flow data were used as input for the Navier-Stokes equations to compute hemodynamic forces over the entire cardiac cycle. Hemodynamic forces were found in a qualitatively consistent pattern in all healthy subjects, with variations in amplitude. LV forces were mainly aligned along the apical-basal longitudinal axis, with an additional component aimed toward the aortic valve during systole. Conversely, RV forces were found in both longitudinal and short-axis planes, with a systolic force component driving a slingshot-like acceleration that explains the mechanism behind the redirection of blood flow toward the pulmonary valve. No differences were found between controls and athletes when indexing forces to ventricular volumes, indicating that cardiac force expenditures are tuned to accelerate blood similarly in small and large hearts. Patients’ forces differed from controls in both timing and amplitude. Normal cardiac pumping is associated with specific force patterns for both ventricles, and deviation from these forces may be a sensitive marker of ventricular dysfunction. Reference values are provided for future studies.NEW & NOTEWORTHY Biventricular hemodynamic forces were quantified for the first time in healthy controls and elite athletes (n = 39). Hemodynamic forces constitute a slingshot-like mechanism in the right ventricle, redirecting blood flow toward the pulmonary circulation. Force patterns were similar between healthy subjects and athletes, indicating potential utility as a cardiac function biomarker.

scholarly journals 4D flow magnetic resonance imaging to assess left atrial haemodynamics in healthy and hypertrophic subjects

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
X Morales Ferez ◽  
J Mill ◽  
G Delso ◽  
M Sitges ◽  
A Doltra ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Spectral Analysis ◽  
Magnetic Resonance ◽  
Healthy Subjects ◽  
Ventricular Dysfunction ◽  
Flow Patterns ◽  
Resonance Imaging ◽  
4D Flow ◽  
Blood Flow Patterns

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): - University, research centre and hospital foundation grants for the contracting of new research staff (FI 2020) - Spanish Ministry of Economy and Competitiveness Retos investigacion project Introduction The assessment of the left atrium (LA) haemodynamics is key to better understand the development of LA-related pathological processes. In this regard 4D flow magnetic resonance imaging (MRI) can provide complementary information to standard Doppler echocardiographic studies and identify complex blood flow patterns. Yet, until recently, the left atrium (LA) has been largely left aside in 4D flow MRI studies. Purpose We aimed at assessing the LA haemodynamics of healthy and hypertrophic cardiomyopathy (HCM) subjects with a qualitative visualization of flow patterns and deriving quantitative indices related to ventricular dysfunction from pulmonary veins (PV)  and mitral valve (MV) velocity profiles. Methods Segmentation was performed directly over 4D flow angiograms. A total of 20 cases were processed, 11 healthy and 9 HCM subjects. 4D velocity matrices were masked with the segmented mask to isolate LA haemodynamics. Velocity profiles were then obtained in the PV and MV and integrated over planes perpendicular to the lumen of the vessels to create velocity spectrograms. Fourier spectral analysis was applied to the velocity curves to highlight differences that might go unnoticed in the time domain. In addition, the Q-Criterion was computed for vortex identification, visually inspecting both cohorts across the whole cardiac cycle. Results Fourier spectral analysis of the velocity curves suggested that overall, healthy patients have higher dynamic range of the velocity curves. It can be observed in Figure 1, that the usual E/A MV velocity pattern is preserved in 10 of the 11 healthy subjects while 5 of the HCM patients present significant alterations of said curve. In fact, patients 4, 6, 7 and 8 seem to present a 3 peaked MV velocity curve. The vortex analysis identified 3 main types of vortices in healthy subjects: a ‘filling’ systolic vortex (10/11) arising near the most dominant PV (usually the left superior PV) as seen in Figure 2; a conduit phase vortex (7/11), similar in nature to the preceding systolic vortex; and an E-wave vortex (9/11) attached to the LA ostium. Four of the HCM patients (out of the five with altered MV velocity profile) also showed a systolic vortex, but with more complex blood flow patterns and emerging far from the PVs. One of such vortices is shown in Figure 2, composed of two distinct eddies near the MV. The E-wave vortex was also observed but was less predominant than in healthy subjects (3/9). Conclusions 4D Flow analysis of the LA is feasible and might hold promise in the understanding of the complex haemodynamics in ventricular dysfunction. Abstract Figure. Velocity Spectrograms and Vortices

scholarly journals Pressure and Flow Interplay in Aortic Dilation Using 4D Flow Magnetic Resonance Imaging

2019 ◽  
Author(s):  
Kevin Bouaou ◽  
Thomas Dietenbeck ◽  
Soulat Gile ◽  
Sophia Houriez--Gombaud-Saintonge ◽  
Bargiotas Ioannis ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Aortic Dilation ◽  
4D Flow

scholarly journals Enhancing Magnetic Resonance Imaging With Computational Fluid Dynamics

2019 ◽  
Vol 2 (4) ◽  
Author(s):  
Giacomo Annio ◽  
Ryo Torii ◽  
Ben Ariff ◽  
Declan P. O'Regan ◽  
Vivek Muthurangu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Patient Specific ◽  
Human Aorta ◽  
Resonance Imaging ◽  
4D Flow ◽  
4D Flow Cmr

Abstract The analysis of the blood flow in the great thoracic arteries does provide valuable information about the cardiac function and can diagnose the potential development of vascular diseases. Flow-sensitive four-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR) is often used to characterize patients' blood flow in the clinical environment. Nevertheless, limited spatial and temporal resolution hinders a detailed assessment of the hemodynamics. Computational fluid dynamics (CFD) could expand this information and, integrated with experimental velocity field, enable to derive the pressure maps. However, the limited resolution of the 4D flow CMR and the simplifications of CFD modeling compromise the accuracy of the computed flow parameters. In this article, a novel approach is proposed, where 4D flow CMR and CFD velocity fields are integrated synergistically to obtain an enhanced MR imaging (EMRI). The approach was first tested on a two-dimensional (2D) portion of a pipe, to understand the behavior of the parameters of the model in this novel framework, and afterwards in vivo, to apply it to the analysis of blood flow in a patient-specific human aorta. The outcomes of EMRI are assessed by comparing the computed velocities with the experimental one. The results demonstrate that EMRI preserves flow structures while correcting for experimental noise. Therefore, it can provide better insights into the hemodynamics of cardiovascular problems, overcoming the limitations of MRI and CFD, even when considering a small region of interest. EMRI confirmed its potential to provide more accurate noninvasive estimation of major cardiovascular risk predictors (e.g., flow patterns, endothelial shear stress) and become a novel diagnostic tool.

Vertigo-Related Cerebral Blood Flow Changes on Magnetic Resonance Imaging

Spine ◽  
2014 ◽  
Vol 39 (23) ◽  
pp. E1374-E1379 ◽  
Author(s):  
Feiyan Chang ◽  
Zhongshi Li ◽  
Sheng Xie ◽  
Hui Liu ◽  
Wu Wang
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Resonance Imaging ◽  
Flow Changes

scholarly journals Multi-Velocity Encoding Four-Dimensional Flow Magnetic Resonance Imaging in the Assessment of Chronic Aortic Dissection

Aorta ◽  
2017 ◽  
Vol 05 (03) ◽  
pp. 80-90
Author(s):  
Andrew Sherrah ◽  
Fraser Callaghan ◽  
Rajesh Puranik ◽  
Richmond Jeremy ◽  
Paul Bannon ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Aortic Dissection ◽  
Surgical Repair ◽  
Resonance Imaging ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri

Background: Chronic descending thoracic aortic dissection (CDTAD) following surgical repair of ascending aortic dissection requires long-term imaging surveillance. We investigated four-dimensional (4D)-flow magnetic resonance imaging (MRI) with a novel multi-velocity encoding (multi-VENC) technique as an emerging clinical method enabling the dynamic quantification of blood volume and velocity throughout the cardiac cycle. Methods: Patients with CDTAD (n = 10; mean age, 55.1 years; standard deviation (SD) 10.8) and healthy volunteers (n = 9; mean age, 37.1 years; SD 11.4; p < 0.01) underwent 3T MRI, and standard views and 4D-flow data were obtained. Flow measurements were made in selected regions of interest within the ascending and descending thoracic aorta. Results: The overall flow profile at peak systole was reduced in the false lumen (FL) compared with the true lumen (TL) and normal aortas (p < 0.05 for velocity < 0.4 m/s). Peak systolic flow rate per aortic lumen area (mL/s/cm2) was lower in the FL than in the TL (p < 0.05), and both rates were lower than that of control aortas (p < 0.05). Blood flow reversal was higher in the FL than in the TL throughout the descending aorta in CDTAD patients (p < 0.05). A derived pulsatility index was elevated in the TL compared with that in the FL in CDTAD patients. Generated pathline images demonstrated flow patterns in detail, including sites of communication between the true and FL. Conclusions: 4D-flow MRI revealed FL blood flow and reduced blood flow velocity and flow rate in the TL of CDTAD patients compared with normal aortas of healthy participants. Thus, multi-VENC 4D-flow MRI could serve as an adjunct in the long-term assessment of CDTAD following surgical repair of ascending aortic dissection.

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