Towards Automatic Identification of Cerebral Arteries in 4D Flow MRI

Recent reports have suggested that age-related arterial stiffening and excessive cerebral arterial pulsatility cause blood–brain barrier breakdown, brain atrophy and cognitive decline. This has spurred interest in developing non-invasive methods to measure pulsatility in distal vessels, closer to the cerebral microcirculation. Here, we report a method based on four-dimensional (4D) flow MRI to estimate a global composite flow waveform of distal cerebral arteries. The method is based on finding and sampling arterial waveforms from thousands of cross sections in numerous small vessels of the brain, originating from cerebral cortical arteries. We demonstrate agreement with internal and external reference methods and show the ability to capture significant increases in distal cerebral arterial pulsatility as a function of age. The proposed approach can be used to advance our understanding regarding excessive arterial pulsatility as a potential trigger of cognitive decline and dementia.

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Comparison of Hemodynamic Visualization in Cerebral Arteries: Can Magnetic Resonance Imaging Replace Computational Fluid Dynamics?

Journal of Personalized Medicine ◽

10.3390/jpm11040253 ◽

2021 ◽

Vol 11 (4) ◽

pp. 253

Author(s):

Minh Tri Ngo ◽

Ui Yun Lee ◽

Hojin Ha ◽

Ning Jin ◽

Gyung Ho Chung ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Cerebral Artery ◽

Internal Carotid ◽

Cerebral Arteries ◽

Resonance Imaging ◽

4D Flow Mri ◽

4D Flow ◽

Tof Mra ◽

Flow Mri

A multimodality approach was applied using four-dimensional flow magnetic resonance imaging (4D flow MRI), time-of-flight magnetic resonance angiography (TOF-MRA) signal intensity gradient (SIG), and computational fluid dynamics (CFD) to investigate the 3D blood flow characteristics and wall shear stress (WSS) of the cerebral arteries. TOF-MRA and 4D flow MRI were performed on the major cerebral arteries in 16 healthy volunteers (mean age 34.7 ± 7.6 years). The flow rate measured with 4D flow MRI in the internal carotid artery, middle cerebral artery, and anterior cerebral artery were 3.8, 2.5, and 1.2 mL/s, respectively. The 3D blood flow pattern obtained through CFD and 4D flow MRI on the cerebral arteries showed reasonable consensus. CFD delivered much greater resolution than 4D flow MRI. TOF-MRA SIG and CFD WSS of the major cerebral arteries showed reasonable consensus with the locations where the WSS was relatively high. However, the visualizations were very different between TOF-MRA SIG and CFD WSS at the internal carotid artery bifurcations, the anterior cerebral arteries, and the anterior communicating arteries. 4D flow MRI, TOF-MRA SIG, and CFD are complementary methods that can provide additional insight into the hemodynamics of the human cerebral artery.

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Accuracy of blood flow assessment in cerebral arteries with 4D flow MRI: Evaluation with three segmentation methods

Journal of Magnetic Resonance Imaging ◽

10.1002/jmri.26641 ◽

2019 ◽

Vol 50 (2) ◽

pp. 511-518 ◽

Cited By ~ 9

Author(s):

Tora Dunås ◽

Madelene Holmgren ◽

Anders Wåhlin ◽

Jan Malm ◽

Anders Eklund

Keyword(s):

Blood Flow ◽

Cerebral Arteries ◽

4D Flow Mri ◽

4D Flow ◽

Segmentation Methods ◽

Flow Mri ◽

Mri Evaluation

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4D-Flow MRI: Beyond the Images

Seminars in Thoracic and Cardiovascular Surgery ◽

10.1053/j.semtcvs.2019.09.008 ◽

2020 ◽

Vol 32 (1) ◽

pp. 35

Author(s):

Pietro Sergio ◽

Antonio Miceli

Keyword(s):

4D Flow Mri ◽

4D Flow ◽

Flow Mri

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4D- Flow- MRI After Aortic Valve Surgery

Case Medical Research ◽

10.31525/ct1-nct04223713 ◽

2020 ◽

Author(s):

Keyword(s):

Aortic Valve ◽

Valve Surgery ◽

Aortic Valve Surgery ◽

4D Flow Mri ◽

4D Flow ◽

Flow Mri

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

Scientific Reports ◽

10.1038/s41598-021-91125-2 ◽

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.

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Associations between haemodynamics and wall enhancement of intracranial aneurysm

Stroke and Vascular Neurology ◽

10.1136/svn-2020-000636 ◽

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.

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

Scientific Reports ◽

10.1038/s41598-021-85315-1 ◽

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.

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