A subject‐specific assessment of measurement errors and their correction in cerebrospinal fluid velocity maps using 4D flow MRI

2021 ◽  
Author(s):  
Selin Yavuz Ilik ◽  
Tomohiro Otani ◽  
Shigeki Yamada ◽  
Yoshiyuki Watanabe ◽  
Shigeo Wada
Keyword(s):  
Cerebrospinal Fluid ◽  
Measurement Errors ◽  
Fluid Velocity ◽  
4D Flow Mri ◽  
4D Flow ◽  
Subject Specific ◽  
Specific Assessment ◽  
Flow Mri

scholarly journals A dual-VENC 4D Flow MRI Framework for Analysis of Subject-Specific Heterogeneous non-linear Vessel Deformation

2020 ◽  
Author(s):  
Jamie Concannon ◽  
Niamh Hynes ◽  
Marie McMullan ◽  
Evelyn Smyth ◽  
Kevin Mattheus Moerman ◽  
...  
Keyword(s):  
In Silico ◽  
Cardiac Cycle ◽  
Human Aorta ◽  
4D Flow Mri ◽  
4D Flow ◽  
Imaging Protocol ◽  
Subject Specific ◽  
Non Linear ◽  
Flow Mri

Advancement of subject-specific in-silico medicine requires new imaging protocols tailored to specific anatomical features, paired with new constitutive model development based on structure/function relationships. In this study we develop a new dual-VENC 4D Flow MRI protocol that provides unprecedented spatial and temporal resolution of in-vivo aortic deformation. All previous dual-VENC 4D Flow MRI studies in the literature focus on an isolated segment of the aorta, which fail to capture the full spectrum of aortic heterogeneity that exists along the vessel length. The imaging protocol developed provides high sensitivity to all blood flow velocities throughout the entire cardiac cycle, overcoming the challenge of accurately measuring the highly unsteady non-uniform flow field in the aorta. Cross sectional area change, volumetric flow rate, and compliance are observed to decrease with distance from the heart, while pulse wave velocity is observed to increase. A non-linear aortic lumen pressure-area relationship is observed throughout the aorta, such that a high vessel compliance occurs during diastole, and a low vessel compliance occurs during systole. This suggests that a single value of compliance may not accurately represent vessel behaviour during a cardiac cycle in-vivo. This high-resolution MRI data provides key information on the spatial variation in non-linear aortic compliance which can significantly advance the state-of-the-art of in-silico diagnostic techniques for the human aorta.

A Dual-VENC Four-Dimensional Flow MRI Framework for Analysis of Subject-Specific Heterogeneous Nonlinear Vessel Deformation

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
J. Concannon ◽  
N. Hynes ◽  
M. McMullen ◽  
E. Smyth ◽  
K. Moerman ◽  
...  
Keyword(s):  
In Silico ◽  
Cardiac Cycle ◽  
Human Aorta ◽  
4D Flow Mri ◽  
4D Flow ◽  
Full Spectrum ◽  
Imaging Protocol ◽  
Subject Specific ◽  
Flow Mri

Abstract Advancement of subject-specific in silico medicine requires new imaging protocols tailored to specific anatomical features, paired with new constitutive model development based on structure/function relationships. In this study, we develop a new dual-velocity encoding coefficient (VENC) 4D flow MRI protocol that provides unprecedented spatial and temporal resolution of in vivo aortic deformation. All previous dual-VENC 4D flow MRI studies in the literature focus on an isolated segment of the aorta, which fail to capture the full spectrum of aortic heterogeneity that exists along the vessel length. The imaging protocol developed provides high sensitivity to all blood flow velocities throughout the entire cardiac cycle, overcoming the challenge of accurately measuring the highly unsteady nonuniform flow field in the aorta. Cross-sectional area change, volumetric flow rate, and compliance are observed to decrease with distance from the heart, while pulse wave velocity (PWV) is observed to increase. A nonlinear aortic lumen pressure–area relationship is observed throughout the aorta such that a high vessel compliance occurs during diastole, and a low vessel compliance occurs during systole. This suggests that a single value of compliance may not accurately represent vessel behavior during a cardiac cycle in vivo. This high-resolution MRI data provide key information on the spatial variation in nonlinear aortic compliance, which can significantly advance the state-of-the-art of in-silico diagnostic techniques for the human aorta.

scholarly journals Compressed-sensing accelerated 4D flow MRI of cerebrospinal fluid dynamics

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Elena Jaeger ◽  
Kristina Sonnabend ◽  
Frank Schaarschmidt ◽  
David Maintz ◽  
Kilian Weiss ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Cerebrospinal Fluid ◽  
Compressed Sensing ◽  
Cerebrospinal Fluid Dynamics ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri

4D-Flow MRI: Beyond the Images

2020 ◽  
Vol 32 (1) ◽  
pp. 35
Author(s):  
Pietro Sergio ◽  
Antonio Miceli
Keyword(s):  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri

scholarly journals Circulation derived from 4D flow MRI correlates with right ventricular dysfunction in patients with tetralogy of Fallot

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nanae Tsuchiya ◽  
Michinobu Nagao ◽  
Yumi Shiina ◽  
Shohei Miyazaki ◽  
Kei Inai ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
Main Pulmonary Artery ◽  
Vortex Formation ◽  
Cine Mri ◽  
Short Axis ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
Rv Function

AbstractWe used 4D-flow MRI to investigate circulation, an area integral of vorticity, in the main pulmonary artery (MPA) as a new hemodynamic parameter for assessing patients with a repaired Tetralogy of Fallot (TOF). We evaluated the relationship between circulation, right ventricular (RV) function and the pulmonary regurgitant fraction (PRF). Twenty patients with a repaired TOF underwent cardiac MRI. Flow-sensitive 3D-gradient sequences were used to obtain 4D-flow images. Vortex formation in the MPA was visualized, with short-axis and longitudinal vorticities calculated by software specialized for 4D flow. The RV indexed end-diastolic/end-systolic volumes (RVEDVi/RVESVi) and RV ejection fraction (RVEF) were measured by cine MRI. The PR fraction (PRF) and MPA area were measured by 2D phase-contrast MRI. Spearman ρ values were determined to assess the relationships between circulation, RV function, and PRF. Vortex formation in the MPA occurred in 15 of 20 patients (75%). The longitudinal circulation (11.7 ± 5.1 m2/s) was correlated with the RVEF (ρ = − 0.85, p = 0.0002), RVEDVi (ρ = 0.62, p = 0.03), and RVESVi (ρ = 0.76, p = 0.003) after adjusting for the MPA size. The short-axis circulation (9.4 ± 3.4 m2/s) in the proximal MPA was positively correlated with the MPA area (ρ = 0.61, p = 0.004). The relationships between the PRF and circulation or RV function were not significant. Increased longitudinal circulation in the MPA, as demonstrated by circulation analysis using 4D flow MRI, was related to RV dysfunction in patients with a repaired TOF.

scholarly journals Associations between haemodynamics and wall enhancement of intracranial aneurysm

2021 ◽  
pp. svn-2020-000636
Author(s):  
Miaoqi Zhang ◽  
Fei Peng ◽  
Xin Tong ◽  
Xin Feng ◽  
Yunduo Li ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Resolution ◽  
Ordinal Regression ◽  
Parent Artery ◽  
Black Blood ◽  
4D Flow Mri ◽  
4D Flow ◽  
Unruptured Intracranial Aneurysms ◽  
Black Blood Mri ◽  
Flow Mri

Background and purposePrevious studies have reported about inflammation processes (IPs) that play important roles in aneurysm formation and rupture, which could be driven by blood flow. IPs can be identified using aneurysmal wall enhancement (AWE) on high-resolution black-blood MRI (BB-MRI) and blood flow haemodynamics can be demonstrated by four-dimensional-flow MRI (4D-flow MRI). Thus, this study investigated the associations between AWE and haemodynamics in unruptured intracranial aneurysms (IA) by combining 4D-flow MRI and high-resolution BB-MRI.Materials and methodsBetween April 2014 and October 2017, 48 patients with 49 unruptured IA who underwent both 4D-flow MRI and high-resolution BB-MRI were retrospectively included in this study. The haemodynamic parameters demonstrated using 4D-flow MRI were compared between different AWE patterns using the Kruskal-Wallis test and ordinal regression.ResultsThe results of Kruskal-Wallis test showed that the average wall shear stress in the IA (WSSavg-IA), maximum through-plane velocity in the adjacent parent artery, inflow jet patterns and the average vorticity in IA (vorticityavg-IA) were significantly associated with the AWE patterns. Ordinal regression analysis identified WSSavg-IA (p=0.002) and vorticityavg-IA (p=0.033) as independent predictors of AWE patterns.ConclusionA low WSS and low average vorticity were independently associated with a high AWE grade for IAs larger than 4 mm. Therefore, WSS and average vorticity could predict AWE and circumferential AWE.

scholarly journals A pilot study investigating the use of 4D flow MRI for the assessment of splanchnic flow in patients suspected of mesenteric ischaemia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pauline Hall Barrientos ◽  
Katrina Knight ◽  
Douglas Black ◽  
Alexander Vesey ◽  
Giles Roditi
Keyword(s):  
Blood Flow ◽  
Pilot Study ◽  
Splenic Vein ◽  
Normal Subjects ◽  
Mesenteric Ischaemia ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
Mesenteric Vessels ◽  
Flow Changes

AbstractThe most common cause of chronic mesenteric ischaemia is atherosclerosis which results in limitation of blood flow to the gastrointestinal tract. This pilot study aimed to evaluate 4D flow MRI as a potential tool for the analysis of blood flow changes post-prandial within the mesenteric vessels. The mesenteric vessels of twelve people were scanned; patients and healthy volunteers. A baseline MRI scan was performed after 6 h of fasting followed by a post-meal scan. Two 4D flow datasets were acquired, over the superior mesenteric artery (SMA) and the main portal venous vessels. Standard 2D time-resolved PC-MRI slices were also obtained across the aorta above the coeliac trunk, superior mesenteric vein, splenic vein and portal vein (PV). In the volunteer cohort there was a marked increase in blood flow post-meal within the PV (p = 0.028), not seen in the patient cohort (p = 0.116). Similarly, there were significant flow changes within the SMA of volunteers (p = 0.028) but not for the patient group (p = 0.116). Our pilot data has shown that there is a significant haemodynamic response to meal challenge in the PV and SMA in normal subjects compared to clinically apparent CMI patients. Therefore, the interrogation of mesenteric venous vessels exclusively is a feasible method to measure post-prandial flow changes in CMI patients.

scholarly journals Four-Dimensional Flow MRI of Abdominal Veins: A Systematic Review

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 767
Author(s):  
Simon O. Haarbye ◽  
Michael B. Nielsen ◽  
Adam E. Hansen ◽  
Carsten A. Lauridsen
Keyword(s):  
Systematic Review ◽  
Blood Flow ◽  
Portal Hypertension ◽  
Healthy Subjects ◽  
Visual Quality ◽  
Sampling Strategies ◽  
4D Flow Mri ◽  
4D Flow ◽  
Dimensional Flow ◽  
Flow Mri

The aim of this systematic review is to provide an overview of the use of Four-Dimensional Magnetic Resonance Imaging of vector blood flow (4D Flow MRI) in the abdominal veins. This study was composed according to the PRISMA guidelines 2009. The literature search was conducted in MEDLINE, Cochrane Library, EMBASE, and Web of Science. Quality assessment of the included studies was performed using the QUADAS-2 tool. The initial search yielded 781 studies and 21 studies were included. All studies successfully applied 4D Flow MRI in abdominal veins. Four-Dimensional Flow MRI was capable of discerning between healthy subjects and patients with cirrhosis and/or portal hypertension. The visual quality and inter-observer agreement of 4D Flow MRI were rated as excellent and good to excellent, respectively, and the studies utilized several different MRI data sampling strategies. By applying spiral sampling with compressed sensing to 4D Flow MRI, the blood flow of several abdominal veins could be imaged simultaneously in 18–25 s, without a significant loss of visual quality. Four-Dimensional Flow MRI might be a useful alternative to Doppler sonography for the diagnosis of cirrhosis and portal hypertension. Further clinical studies need to establish consensus regarding MRI sampling strategies in patients and healthy subjects.

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