Hemodynamic aspects of mitral regurgitation assessed by generalized phase‐contrast MRI

Dyverfeldt, Petter; Kvitting, John‐Peder Escobar; Carlhäll, Carl‐Johan; Boano, Gabriella; Sigfridsson, Andreas; Hermansson, Ulf; Bolger, Ann F.; Engvall, Jan; Ebbers, Tino

doi:10.1002/jmri.22407

Cited by 40 publications

(65 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dyverfeldt et al (23), looked at a group of five patients with mitral valve prolapse of the middle scallop, they found a linear correlation between TKE values and regurgitant volume. Otherwise, TKE studies in the current literature have presented aortic flow.…”

Section: Turbulent Kinetic Energymentioning

confidence: 99%

Quantification of 4D Left Ventricular Blood Flow in Health and Disease

Eriksson¹

2013

View full text Add to dashboard Cite

The main function of the heart is to pump blood throughout the cardiovascular system by generating pressure differences created through volume changes. Although the main purpose of the heart and vessels is to lead the flowing blood throughout the body, clinical assessments of cardiac function are usually based on morphology, approximating the flow features by viewing the motion of the myocardium and vessels. Measurement of three-directional, three-dimensional and time-resolved velocity (4D Flow) data is feasible using magnetic resonance (MR). The focus of this thesis is the development and application of methods that facilitate the analysis of larger groups of data in order to increase our understanding of intracardiac flow patterns and take the 4D flow technique closer to the clinical setting.In the first studies underlying this thesis, a pathline based method for analysis of intra ventricular blood flow patterns has been implemented and applied. A pathline is integrated from the velocity data and shows the path an imaginary massless particle would take through the data volume. This method separates the end-diastolic volume (EDV) into four functional components, based on the position for each individual pathline at end-diastole (ED) and end-systole (ES). This approach enables tracking of the full EDV over one cardiac cycle and facilitates calculation of parameters such as e.g. volumes and kinetic energy (KE). Besides blood flow, pressure plays an important role in the cardiac dynamics. In order to study this parameter in the left ventricle, the relative pressure field was computed using the pressure Poisson equation. A comprehensive presentation of the pressure data was obtained dividing the LV blood pool into 17 pie-shaped segments based on a modification of the standard seventeen segment model. Further insight into intracardiac blood flow dynamics was obtained by studying the turbulent kinetic energy (TKE) in the LV. The methods were applied to data from a group of healthy subjects and patients with dilated cardiomyopathy (DCM). DCM is a pathological state where the cardiac function is impaired and the left ventricle or both ventricles are dilated.The validation study of the flow analysis method showed that a reliable user friendly tool for intra ventricular blood flow analysis was obtained. The application of this tool also showed that roughly one third of the blood that enters the LV, directly leaves the LV again in the same heart beat. The distribution of the four LV EDV components was altered in the DCM group as compared to the healthy group; the component that enters and leaves the LV during one cardiac cycle (Direct Flow) was significantly larger in the healthy subjects. Furthermore, when the kinetic energy was normalized by the volume for each component, at time of ED, the Direct Flow had the highest values in the healthy subjects. In the DCM group, however, the Retained Inflow and Delayed Ejection Flow had higher values. The relative pressure field showed to be highly heterogeneous, in the hea...

show abstract

Section: Turbulent Kinetic Energymentioning

confidence: 99%

Quantification of 4D Left Ventricular Blood Flow in Health and Disease

Eriksson¹

2013

View full text Add to dashboard Cite

show abstract

“…However, recent developments have extended 4D Flow MRI to permit estimation of velocity fluctuation intensity and turbulent kinetic energy (TKE) (12,19,20). This approach has been validated and demonstrated in a variety of applications (21)(22)(23)(24)(25).…”

Section: Introductionmentioning

confidence: 99%

Assessment of turbulent flow effects on the vessel wall using four-dimensional flow MRI

et al. 2016

Self Cite

View full text Add to dashboard Cite

PurposeTo explore the use of MR-estimated turbulence quantities for the assessment of turbulent flow effects on the vessel wall. MethodsNumerical velocity data for two patient-derived models was obtained using computational fluid dynamics (CFD) for two physiological flow rates. 4D Flow MRI measurements were simulated at three different spatial resolutions and used to investigate the estimation of turbulent wall shear stress (tWSS) using the intravoxel standard deviation (IVSD) of velocity and turbulent kinetic energy (TKE) estimated near the vessel wall. ResultsAccurate estimation of tWSS using the IVSD is limited by the spatial resolution achievable with 4D Flow MRI. TKE, estimated near the wall, has a strong linear relationship to the tWSS (mean R 2 = 0.84). Near-wall TKE estimates from MR simulations have good agreement to CFD-derived ground truth (mean R 2 = 0.90). Maps of near-wall TKE have strong visual correspondence to tWSS. ConclusionNear-wall estimation of TKE permits assessment of relative maps of tWSS, but direct estimation of tWSS is challenging due to limitations in spatial resolution. Assessment of tWSS and nearwall TKE may open new avenues for analysis of different pathologies.

show abstract

“…These blood flow patterns may have beneficial effects in avoiding left atrial stasis in the normal subject in sinus rhythm. While the dominant systolic vortex in healthy volunteers was situated in proximity to the left sided pulmonary veins, in patients with mitral regurgitation the systolic vortex was instead located in proximity to the regurgitant jet (42). In these patients, elevated turbulent kinetic energy was observed in the left atrium.…”

Section: Intracardiac Blood Flow In Health and Diseasementioning

confidence: 90%

Flow Imaging: Cardiac Applications of 3D Cine Phase-Contrast MRI

Ebbers

2011

Curr Cardiovasc Imaging Rep

Self Cite

View full text Add to dashboard Cite

Global and regional blood flow dynamics are of pivotal importance to cardiac function. Fluid mechanical forces can affect hemolysis and platelet aggregation, as well as myocardial remodeling. In recent years, assessment of blood flow patterns based on time-resolved, three-dimensional, three-directional phasecontrast magnetic resonance imaging (3D cine PC MRI)(1) has become possible and rapidly gained popularity. Initially, this technique was mainly known for its intuitive and appealing visualizations of the cardiovascular blood flow. Most recently, the technique has begun to go beyond compelling images towards comprehensive and quantitative assessment of blood flow. In this article, cardiac applications of 3D cine PC MRI data are discussed, starting with a review of the acquisition and analysis techniques, and including descriptions of promising applications of cardiac 3D cine PC MRI for the clinical evaluation of myocardial, valvular and vascular disorders.3

show abstract

Hemodynamic aspects of mitral regurgitation assessed by generalized phase‐contrast MRI

Cited by 40 publications

References 35 publications

Quantification of 4D Left Ventricular Blood Flow in Health and Disease

Quantification of 4D Left Ventricular Blood Flow in Health and Disease

Assessment of turbulent flow effects on the vessel wall using four-dimensional flow MRI

Flow Imaging: Cardiac Applications of 3D Cine Phase-Contrast MRI

Contact Info

Product

Resources

About