scholarly journals Assessment of ventricular flow dynamics by 4D-flow MRI in patients following surgical repair of d-transposition of the great arteries

2021 ◽  
Author(s):  
Fraser M. Callaghan ◽  
Barbara Burkhardt ◽  
Emanuela R. Valsangiacomo Buechel ◽  
Christian J. Kellenberger ◽  
Julia Geiger
Keyword(s):  
Normal Subjects ◽  
Flow Dynamics ◽  
4D Flow Mri ◽  
4D Flow ◽  
Direct Flow ◽  
Arterial Switch ◽  
Atrial Switch ◽  
Intraventricular Flow ◽  
Flow Mri ◽  
Flow Components

Abstract Objectives To use 4D-flow MRI to describe systemic and non-systemic ventricular flow organisation and energy loss in patients with repaired d-transposition of the great arteries (d-TGA) and normal subjects. Methods Pathline tracking of ventricular volumes was performed using 4D-flow MRI data from a 1.5-T GE Discovery MR450 scanner. D-TGA patients following arterial switch (n = 17, mean age 14 ± 5 years) and atrial switch (n = 15, 35 ± 6 years) procedures were examined and compared with subjects with normal cardiac anatomy and ventricular function (n = 12, 12 ± 3 years). Pathlines were classified by their passage through the ventricles as direct flow, retained inflow, delayed ejection flow, and residual volume and visually and quantitatively assessed. Additionally, viscous energy losses (ELv) were calculated. Results In normal subjects, the ventricular flow paths were well ordered following similar trajectories through the ventricles with very little mixing of flow components. The flow paths in all atrial and some arterial switch patients were more irregular with high mixing. Direct flow and delayed ejection flow were decreased in atrial switch patients’ systemic ventricles with a corresponding increase in residual volume compared with normal subjects (p = 0.003 and p < 0.001 respectively) and arterial switch patients (p < 0.0001 and p < 0.001 respectively). In non-systemic ventricles, arterial switch patients had increased direct flow and decreased delayed ejection fractions compared to normal (p = 0.007 and p < 0.001 respectively) and atrial switch patients (p = 0.01 and p < 0.001 respectively). Regions of high levels of mixing of ventricular flow components showed elevated ELv. Conclusions 4D-flow MRI pathline tracking reveals disordered ventricular flow patterns and associated ELv in d-TGA patients. Key Points • 4D-flow MRI can be used to assess intraventricular flow dynamics in d-TGA patients. • d-TGA arterial switch patients mostly show intraventricular flow dynamics representative of normal subjects, while atrial switch patients show increased flow disorder and different proportions of intraventricular flow volumes. • Flow disruption and disorder increase viscous energy losses.

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.

Sildenafil Administration Improves Right Ventricular Function on 4D Flow MRI in Young Adults Born Premature

2021 ◽  
Author(s):  
Philip A Corrado ◽  
Gregory P Barton ◽  
Christopher J François ◽  
Oliver Wieben ◽  
Kara N Goss
Keyword(s):  
Heart Rate ◽  
Young Adults ◽  
Kinetic Energy ◽  
Right Ventricular ◽  
Right Atrial ◽  
4D Flow Mri ◽  
4D Flow ◽  
Direct Flow ◽  
Flow Mri ◽  
Rv Function

Background: Extreme preterm birth conveys an elevated risk of heart failure by young adulthood. Smaller biventricular chamber size, diastolic dysfunction, and pulmonary hypertension may contribute to reduced ventricular-vascular coupling. However, how hemodynamic manipulations may affect right ventricular (RV) function and coupling remains unknown. Methods: As a pilot study, 4D flow MRI was used to assess the effect of afterload reduction and heart rate reduction on cardiac hemodynamics and function. Young adults born premature were administered sildenafil (a pulmonary vasodilator) and metoprolol (a beta blocker) on separate days, and MRI with 4D flow completed before and after each drug administration. Endpoints include cardiac index (CI), direct flow fractions, and ventricular kinetic energy including E/A wave kinetic energy ratio. Results: Sildenafil resulted in a median CI increase of 0.24 L/min/m2 (P=0.02), mediated through both an increase in heart rate (HR) and stroke volume. Although RV ejection fraction improved only modestly, there was a significant increase (4% of end diastolic volume) in RV direct flow fraction (P=0.04), consistent with hemodynamic improvement. Metoprolol administration resulted in a 5-bpm median decrease in HR (P=0.01), a 0.37 L/min/m2 median decrease in CI (P=0.04), and a reduction in time-averaged kinetic energy (KE) in both ventricles (P<0.01), despite increased RV diastolic E/A KE ratio (P=0.04). Conclusions: Despite reduced right atrial workload, metoprolol significantly depressed overall cardiac systolic function. Sildenafil, however, increased CI and improved RV function, as quantified by the direct flow fraction. The preterm heart appears dependent on HR, but sensitive to RV afterload manipulations.

Neopulmonary Outflow Tract Obstruction Assessment by 4D Flow MRI in Adults With Transposition of the Great Arteries After Arterial Switch Operation

2019 ◽  
Vol 51 (6) ◽  
pp. 1699-1705 ◽  
Author(s):  
Zahra Belhadjer ◽  
Gilles Soulat ◽  
Magalie Ladouceur ◽  
Francesca Pitocco ◽  
Antoine Legendre ◽  
...  
Keyword(s):  
Arterial Switch Operation ◽  
Outflow Tract ◽  
4D Flow Mri ◽  
4D Flow ◽  
Arterial Switch ◽  
Switch Operation ◽  
Flow Mri

scholarly journals 3D Heart Model and 4D Flow MRI 20 Years after Spiral Arterial Switch Operation

2016 ◽  
Vol 05 (01) ◽  
pp. 44-46 ◽  
Author(s):  
Arash Kheradvar ◽  
Hans-Heiner Kramer ◽  
Carsten Rickers ◽  
Hans-Hinrich Sievers
Keyword(s):  
Arterial Switch Operation ◽  
Heart Model ◽  
4D Flow Mri ◽  
4D Flow ◽  
Arterial Switch ◽  
Switch Operation ◽  
Flow Mri

Age-related changes of shape and flow dynamics in healthy adult aortas: A 4D flow MRI study

2018 ◽  
Vol 49 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Fraser M. Callaghan ◽  
Paul Bannon ◽  
Edward Barin ◽  
David Celemajer ◽  
Richmond Jeremy ◽  
...  
Keyword(s):  
Healthy Adult ◽  
Flow Dynamics ◽  
4D Flow Mri ◽  
4D Flow ◽  
Age Related ◽  
Flow Mri ◽  
Mri Study ◽  
Age Related Changes

Abstract 16422: 4D Flow MRI Improves Assessment of Aortic and Pulmonary Peak Velocities in Patients With D-Transposition of Great Arteries Following Arterial Switch Operation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Kelly Jarvis ◽  
Susanne Schnell ◽  
Alex Barker ◽  
Marleen Vonder ◽  
Michael Rose ◽  
...  
Keyword(s):  
Peak Velocity ◽  
Arterial Switch Operation ◽  
Pulmonary Arteries ◽  
Velocity Measurements ◽  
4D Flow Mri ◽  
4D Flow ◽  
Arterial Switch ◽  
Switch Operation ◽  
Significant Difference ◽  
Flow Mri

BACKGROUND: Pulmonary artery stenosis is the most common complication seen following the arterial switch operation (ASO) for D-transposition of the great arteries (DTGA). During follow-up, it is important to accurately detect peak velocity as an indicator of vessel narrowing. The purpose of this study was to compare peak velocity measurements by 4D flow MRI (4D flow) (with full volumetric coverage of aorta and pulmonary system) to those by standard 2D phase contrast MRI (2D PC) and Doppler echo. METHODS: 4D flow and 2D PC were performed in n=14 subjects (age = 12.4 ± 7.6, range = 1 to 25) with DTGA s/p ASO. 3D segmentation of the aorta (Ao) and pulmonary arteries (PAs) was performed to isolate 4D flow velocities for these vessels (Figure a). The location and value of peak systolic velocity was determined inside volumes of interest for the ascending aorta (AAO), main (MPA), right (RPA) and left pulmonary arteries (LPA). RPA and LPA 2D PC data were not available in one patient. Contemporary echo data were available in 11 patients (11 AAO, 8 MPA, 6 RPA, 5 LPA). RESULTS: Peak velocity measurements by 4D flow were significantly higher than 2D PC in all regions (AAO: 1.51±0.61m/s vs. 1.15±0.24m/s, p = 0.016; MPA: 2.08±1.11m/s vs. 1.44± 0.61m/s, p = 0.004; RPA: 2.19±0.65m/s vs. 1.79±0.81m/s, p = 0.027; LPA: 2.08±0.85m/s vs. 1.74±0.70m/s, p = 0.014). Regression results indicated strong relationships between 4D flow and 2D PC (AAO: R2 = 0.46, p = 0.008; MPA: R2 = 0.69, p = 0.0002; RPA: R2 =0.50, p = 0.007; LPA: R2 = 0.74, p = 0.0001) (Figure b). No significant difference was found between peak velocities measured by 4D flow and echo (AAO: p = 0.32, MPA: p = 0.24, RPA: p = 0.91, LPA: p = 0.36) or by 2D PC and echo (AAO: p = 0.49, MPA: p = 0.62, RPA: p = 0.35, LPA: p = 0.066). CONCLUSION: 4D flow outperformed 2D PC for detecting peak velocity in the Ao and PAs. No significant difference was found between peak velocities measured by 4D flow and echo. Further studies are warranted in a larger patient cohort to determine clinical impact.

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