Background It has been demonstrated that the rate of aortic dilatation is influenced by alteration of aortic hemodynamics, such as normalized flow displacement (FDN) and wall shear stress (WSS).... Show moreBackground It has been demonstrated that the rate of aortic dilatation is influenced by alteration of aortic hemodynamics, such as normalized flow displacement (FDN) and wall shear stress (WSS). However, the effects of ageing on aortic hemodynamics have not yet been described. Case summary 4D-Flow MRI derived aorta hemodynamics were derived in the ascending aorta of a patient with ascending aortic aneurysm (mean +/- standard deviation: 46 +/- 1 mm) and a healthy volunteer (aortic diameter 30 +/- 1 mm) with long-term follow-up of ten and eight years, respectively. At all timepoints, compared to the healthy volunteer, the patient demonstrated higher magnitudes of FDN (7% +/- 1% vs. 3% +/- 1%) and WSS angle (36 degrees +/- 3 degrees vs. 24 degrees +/- 6 degrees), and lower WSS magnitude (565 +/- 100 mPa vs. 910 +/- 115 mPa), axial WSS (426 +/- 71 mPa vs. 800 +/- 108 mPa) and circumferential WSS (297 +/- 64 mPa vs. 340 +/- 85 mPa). The patient and healthy volunteer demonstrated different aortic dilatation rates (regression slope +/- standard error: 0.2 +/- 0.1 vs. 0.1 +/- 0.2 mm per year) and trends in FDN (0.1% +/- 0.1% vs. 0.1% +/- 0.2% per year), WSS magnitude (22 +/- 9 vs. 35 +/- 13 mPa per year), axial WSS (19 +/- 4 vs. 37 +/- 7 mPa per year), circumferential WSS (9 +/- 8 vs. 5 +/- 15 mPa per year), and WSS angle (-0.5 degrees +/- 0.4 degrees vs. -0.8 degrees +/- 1.0 degrees per year). Discussion Aortic hemodynamic parameters are marginally affected by ageing and the aortic diameter in this case series. Since aortic hemodynamic parameters have been associated with aortic dilation by previous studies, the outcomes of the two subjects suggest that the aortic dilatation rate will remain constant while individuals are ageing and dilating. Show less
OBJECTIVES: To date, it is not known if 16-20-mm extracardiac conduits are outgrown during somatic growth from childhood to adolescence. This study aims to determine total cavopulmonary connection ... Show moreOBJECTIVES: To date, it is not known if 16-20-mm extracardiac conduits are outgrown during somatic growth from childhood to adolescence. This study aims to determine total cavopulmonary connection (TCPC) haemodynamics in adolescent Fontan patients at rest and during simulated exercise and to assess the relationship between conduit size and haemodynamics. METHODS: Patient-specific, magnetic resonance imaging-based computational fluid dynamic models of the TCPC were performed in 51 extracardiac Fontan patients with 16-20-mm conduits. Power loss, pressure gradient and normalized resistance were quantified in rest and during simulated exercise. The cross-sectional area (CSA) (mean and minimum) of the vessels of the TCPC was determined and normalized for flow rate (mm(2)/l/min). Peak (predicted) oxygen uptake was assessed. RESULTS: The median age was 16.2 years (Q1-Q3 14.0-18.2). The normalized mean conduit CSA was 35-73% smaller compared to the inferior and superior vena cava, hepatic veins and left/right pulmonary artery (all P < 0.001). The median TCPC pressure gradient was 0.7 mmHg (Q1-Q3 0.5-0.8) and 2.0 (Q1-Q3 1.4-2.6) during rest and simulated exercise, respectively. A moderate-strong inverse non-linear relationship was present between normalized mean conduit CSA and TCPC haemodynamics in rest and exercise. TCPC pressure gradients of >= 1.0 at rest and >= 3.0 mmHg during simulated exercise were observed in patients with a conduit CSA <= 45 mm(2)/l/min and favourable haemodynamics (< 1 mmHg during both rest and exercise) in conduits >= 125 mm(2)/l/min. Normalized TCPC resistance correlated with (predicted) peak oxygen uptake. CONCLUSIONS: Extracardiac conduits of 16-20 mm have become relatively undersized in most adolescent Fontan patients leading to suboptimal haemodynamics. Show less
Aim This study explores the relationship between in vivo 4D flow cardiovascular magnetic resonance (CMR) derived blood flow energetics in the total cavopulmonary connection (TCPC), exercise... Show moreAim This study explores the relationship between in vivo 4D flow cardiovascular magnetic resonance (CMR) derived blood flow energetics in the total cavopulmonary connection (TCPC), exercise capacity and CMR-derived liver fibrosis/congestion. Background The Fontan circulation, in which both caval veins are directly connected with the pulmonary arteries (i.e. the TCPC) is the palliative approach for single ventricle patients. Blood flow efficiency in the TCPC has been associated with exercise capacity and liver fibrosis using computational fluid dynamic modelling. 4D flow CMR allows for assessment of in vivo blood flow energetics, including kinetic energy (KE) and viscous energy loss rate (EL). Methods Fontan patients were prospectively evaluated between 2018 and 2021 using a comprehensive cardiovascular and liver CMR protocol, including 4D flow imaging of the TCPC. Peak oxygen consumption (VO2) was determined using cardiopulmonary exercise testing (CPET). Iron-corrected whole liver T1 (cT1) mapping was performed as a marker of liver fibrosis/congestion. KE and EL in the TCPC were computed from 4D flow CMR and normalized for inflow. Furthermore, blood flow energetics were compared between standardized segments of the TCPC. Results Sixty-two Fontan patients were included (53% male, 17.3 +/- 5.1 years). Maximal effort CPET was obtained in 50 patients (peak VO2 27.1 +/- 6.2 ml/kg/min, 56 +/- 12% of predicted). Both KE and EL in the entire TCPC (n = 28) were significantly correlated with cT1 (r = 0.50, p = 0.006 and r = 0.39, p = 0.04, respectively), peak VO2 (r = - 0.61, p = 0.003 and r = - 0.54, p = 0.009, respectively) and % predicted peak VO2 (r = - 0.44, p = 0.04 and r = - 0.46, p = 0.03, respectively). Segmental analysis indicated that the most adverse flow energetics were found in the Fontan tunnel and left pulmonary artery. Conclusions Adverse 4D flow CMR derived KE and EL in the TCPC correlate with decreased exercise capacity and increased levels of liver fibrosis/congestion. 4D flow CMR is promising as a non-invasive screening tool for identification of patients with adverse TCPC flow efficiency. Show less
Background: Aortic aneurysm formation is associated with increased risk of aortic dissection. Current diagnostic strategies are focused on diameter growth, the predictive value of aortic morphology... Show moreBackground: Aortic aneurysm formation is associated with increased risk of aortic dissection. Current diagnostic strategies are focused on diameter growth, the predictive value of aortic morphology and function remains underinvestigated. We aimed to assess the long-term prognostic value of ascending aorta (AA) curvature radius, regional pulse wave velocity (PWV) and flow displacement (FD) on aortic dilatation/elongation and evaluated adverse outcomes (proximal aortic surgery, dissection/rupture, death) in Marfan and non-syndromic thoracic aortic aneurysm (NTAA) patients.Methods: Long-term magnetic resonance imaging (MRI) and clinical follow-up of two previous studies consisting of 21 Marfan and 40 NTAA patients were collected. Baseline regional PWV, AA curvature radius and normalized FD were assessed as well as diameter and length growth rate at follow-up. Multivariate linear regression was performed to evaluate whether baseline predictors were associated with aortic growth.=.Results: Of the 61 patients, 49 patients were included with MRI follow-up (n = 44) and/or adverse aortic events (n = 7). Six had undergone aortic surgery, no dissection/rupture occurred and one patient died during follow-up. During 8.0 [7.3-10.7] years of follow-up, AA growth rate was 0.40 +/- 0.31 mm/year. After correction for confounders, AA curvature radius (p = 0.01), but not FD or PWV, was a predictor of AA dilatation. Only FD was associated with AA elongation (p = 0.01).Conclusion: In Marfan and non-syndromic thoracic aortic aneurysm patients, ascending aorta curvature radius and flow displacement are associated with accelerated aortic growth at long-term follow-up. These markers may aid in the risk stratification of ascending aorta elongation and aneurysm formation. Show less
Rijnberg, F.M.; Woude, S.F.S. van der; Hazekamp, M.G.; Boogaard, P.J. van den; Lamb, H.J.; Monteros, C.T.E. de los; ... ; Roest, A.A.W. 2021
OBJECTIVES: Adequacy of 16-20mm extracardiac conduits for adolescent Fontan patients remains unknown. This study aims to evaluate conduit adequacy using the inferior vena cava (IVC)-conduit... Show moreOBJECTIVES: Adequacy of 16-20mm extracardiac conduits for adolescent Fontan patients remains unknown. This study aims to evaluate conduit adequacy using the inferior vena cava (IVC)-conduit velocity mismatch factor along the respiratory cycle.METHODS: Real-time 2D flow MRI was prospectively acquired in 50 extracardiac (16-20mm conduits) Fontan patients (mean age 16.9 +/- 4.5 years) at the subhepatic IVC, conduit and superior vena cava. Hepatic venous flow was determined by subtracting IVC flow from conduit flow. The cross-sectional area (CSA) was reported for each vessel. Mean flow and velocity was calculated during the average respiratory cycle, inspiration and expiration. The IVC-conduit velocity mismatch factor was determined as follows: V-conduit/V-IVC where V is the mean velocity.RESULTS: Median conduit CSA and IVC CSA were 221 mm(2) (Q1-Q3 201-255) and 244 mm(2) (Q1-Q3 203-265), respectively. From the IVC towards the conduit, flow rates increased significantly due to the entry of hepatic venous flow (IVC 1.9, Q1-Q3 1.5-2.2) versus conduit (3.3, Q1-Q3 2.5-4.0 1/min, P < 0.001). Consequently, mean velocity significantly increased (IVC 12 (Q1-Q3 11-14 cm/s) versus conduit 25 (Q1-Q3 17-31 cm/s), P < 0.001), resulting in a median IVC-conduit velocity mismatch of 1.8 (Q1-Q3 1.5-2.4), further augmenting during inspiration (median 2.3, Q1-Q3 1.8-3.0). IVC-conduit mismatch was inversely related to measured conduit size and positively correlated with conduit flow. The normalized IVC-conduit velocity mismatch factor during expiration and the entire respiratory cycle correlated with peak VO2 (r = -0.37, P = 0.014 and r = -0.31, P = 0.04, respectively).CONCLUSIONS: Important blood flow accelerations are observed from the IVC towards the conduit in adolescent Fontan patients, which is related to peak VO2. This study, therefore, raises concerns that implanted 16-20mm conduits have become undersized for older Fontan patients and future studies should clarify its effect on long-term outcome. Show less
Perinajova, R.; Juffermans, J.F.; Westenberg, J.J.M.; Palen, R.L.F. van der; Boogaard, P.J. van den; Lamb, H.J.; Sasa 2021
The purpose of this study was to directly assess (patho)physiology of intraventricular hemodynamic interplay between fourdimensional flow cardiovascular magnetic resonance imaging (4D Flow MRI)... Show moreThe purpose of this study was to directly assess (patho)physiology of intraventricular hemodynamic interplay between fourdimensional flow cardiovascular magnetic resonance imaging (4D Flow MRI)-derived vorticity with kinetic energy (KE) and viscous energy loss (EL) over the cardiac cycle and their association to ejection fraction (EF) and stroke volume (SV). Fifteen healthy subjects and thirty Fontan patients underwent whole heart 4D Flow MRI. Ventricular vorticity, KE, and EL were computed over systole (vorticity_volavg systole, KEavg systole, and ELavg systole) and diastole (vorticity_volavg diastole, KEavg diastole, and ELavg diastole). The association between vorticity_vol and KE and EL was tested by Spearman correlation. Fontan patients were grouped to normal and impaired EF groups. A significant correlation was found between SV and vorticity in healthy subjects (systolic: r = 0.84, P < 0.001; diastolic: r = 0.81, P < 0.001) and in Fontan patients (systolic: r = 0.61, P < 0.001; diastolic: r = 0.54, P = 0.002). Healthy subjects showed positive correlation between vorticity_vol versus KE (systole: r = 0.96, P < 0.001; diastole: r = 0.90, P < 0.001) and EL (systole: r = 0.85, P < 0.001; diastole: r = 0.84, P < 0.001). Fontan patients showed significantly elevated vorticity_vol compared with healthy subjects (vorticity_volavg systole: 3.1 [2.3-3.9] vs. 1.7 [1.3-2.4] L/s, P < 0.001; vorticity_volavg diastole: 3.1 [2.03.7] vs. 2.1 [1.6-2.8] L/s, P = 0.002). This elevated vorticity in Fontan patients showed strong association with KE (systole: r = 0.91, P < 0.001; diastole: r = 0.85, P < 0.001) and EL (systole: r = 0.82, P < 0.001; diastole: r = 0.89, P < 0.001). Fontan patients with normal EF showed significantly higher vorticity_volavg systole and ELavg systole, but significantly decreased KE avg diastole, in the presence of normal SV, compared with healthy subjects. Healthy subjects show strong physiological hemodynamic interplay between vorticity with KE and EL. Fontan patients demonstrate a pathophysiological hemodynamic interplay characterized by correlation of elevated vorticity with KE and EL in the presence of maintained normal stroke volume. Altered vorticity and energetic hemodynamics are found in the presence of normal EF in Fontan patients.NEW & NOTEWORTHY Physiologic intraventricular hemodynamic interplay/coupling is present in the healthy left ventricle between vorticity versus viscous energy loss and kinetic energy from four-dimensional flow cardiovascular magnetic resonance imaging (4D Flow MRI). Conversely, Fontan patients present compensatory pathophysiologic hemodynamic coupling by an increase in intraventricular vorticity that positively correlates to viscous energy loss and kinetic energy levels in the presence of maintained normal stroke volume. Altered vorticity and energetics are found in the presence of normal ejection fraction in Fontan patients. Show less
Long scan times prohibit a widespread clinical applicability of 4D flow MRI in Fontan patients. As pulsatility in the Fontan pathway is minimal during the cardiac cycle, acquiring non-ECG gated 3D... Show moreLong scan times prohibit a widespread clinical applicability of 4D flow MRI in Fontan patients. As pulsatility in the Fontan pathway is minimal during the cardiac cycle, acquiring non-ECG gated 3D flow MRI may result in a reduction of scan time while accurately obtaining time-averaged clinical parameters in comparison with 2D and 4D flow MRI. Thirty-two Fontan patients prospectively underwent 2D (reference), 3D and 4D flow MRI of the Fontan pathway. Multiple clinical parameters were assessed from time-averaged flow rates, including the right-to-left pulmonary flow distribution (main endpoint) and systemic-to-pulmonary collateral flow (SPCF). A ten-fold reduction in scan time was achieved [4D flow 15.9 min (SD 2.7 min) and 3D flow 1.6 min (SD 7.8 s), p<0.001] with a superior signal-to-noise ratio [mean ratio of SNRs 1.7 (0.8), p<0.001] and vessel sharpness [mean ratio 1.2 (0.4), p=0.01] with 3D flow. Compared to 2D flow, good-excellent agreement was shown for mean flow rates (ICC 0.82-0.96) and right-to-left pulmonary flow distribution (ICC 0.97). SPCF derived from 3D flow showed good agreement with that from 4D flow (ICC 0.86). 3D flow MRI allows for obtaining time-averaged flow rates and derived clinical parameters in the Fontan pathway with good-excellent agreement with 2D and 4D flow, but with a tenfold reduction in scan time and significantly improved image quality compared to 4D flow. Show less
Juffermans, J.F.; Westenberg, J.J.M.; Boogaard, P.J. van den; Roest, A.A.W.; Assen, H.C. van; Palen, R.L.F. van der; Lamb, H.J. 2020
Background Hemodynamic aorta parameters can be derived from 4D flow MRI, but this requires lumen segmentation. In both commercially available and research 4D flow MRI software tools, lumen... Show moreBackground Hemodynamic aorta parameters can be derived from 4D flow MRI, but this requires lumen segmentation. In both commercially available and research 4D flow MRI software tools, lumen segmentation is mostly (semi-)automatically performed and subsequently manually improved by an observer. Since the segmentation variability, together with 4D flow MRI data and image processing algorithms, will contribute to the reproducibility of patient-specific flow properties, the observer's lumen segmentation reproducibility and repeatability needs to be assessed.Purpose To determine the interexamination, interobserver reproducibility, and intraobserver repeatability of aortic lumen segmentation on 4D flow MRI.Study Type Prospective and retrospective.Population A healthy volunteer cohort of 10 subjects who underwent 4D flow MRI twice. Also, a clinical cohort of six subjects who underwent 4D flow MRI once.Field Strength/Sequence 3T; time-resolved three-directional and 3D velocity-encoded sequence (4D flow MRI).Assessment The thoracic aorta was segmented on the 4D flow MRI in five systolic phases. By positioning six planes perpendicular to a segmentation's centerline, the aorta was divided into five segments. The volume, surface area, centerline length, maximal diameter, and curvature radius were determined for each segment.Statistical Tests To assess the reproducibility, the coefficient of variation (COV), Pearson correlation coefficient (r), and intraclass correlation coefficient (ICC) were calculated.Results The interexamination and interobserver reproducibility and intraobserver repeatability were comparable for each parameter. For both cohorts there was very good reproducibility and repeatability for volume, surface area, and centerline length (COV = 10-32%, r = 0.54-0.95 and ICC = 0.65-0.99), excellent reproducibility and repeatability for maximal diameter (COV = 3-11%, r = 0.94-0.99, ICC = 0.94-0.99), and good reproducibility and repeatability for curvature radius (COV = 25-62%, r = 0.73-0.95, ICC = 0.84-0.97).Data Conclusion This study demonstrated no major reproducibility and repeatability limitations for 4D flow MRI aortic lumen segmentation.Level of Evidence 3Technical Efficacy Stage 2 Show less
Background Patients with transposition of the great arteries (TGA) have an altered aortic geometry after an arterial switch operation (ASO), with neo-aortic root dilatation as an important... Show moreBackground Patients with transposition of the great arteries (TGA) have an altered aortic geometry after an arterial switch operation (ASO), with neo-aortic root dilatation as an important complication. Geometry-related aortic hemodynamics have been assumed to contribute to pathology of the ascending aorta (AAo).Purpose To evaluate aortic flow displacement (FD) and regional wall shear stress (WSS) in relation to ascending neo-aortic geometry in children after ASO.Study Type Prospective.Population Twenty-eight TGA patients after ASO and 10 healthy volunteers.Field Strength/Sequence 3.0T/4D flow (segmented fast-spoiled echo pulse), noncontrast-enhanced MR angiography (Dixon), and anatomic images (SSFP).Assessment Aortic diameters and body surface area-indexed aortic dimensions (Z-scores), normalized FD and planar ascending aortic WSS.Statistical Tests Mann-Whitney and chi-square tests for differences in FD magnitude, WSS, and FD directionality between groups, respectively. Spearman rank correlation to assess the degree of association between aortic geometry, FD and WSS parameters. Shapiro-Wilk test to evaluate distribution normality on the absolute differences in octant location between FD and WSS.Results TGA patients showed a significantly dilated proximal AAo and relatively small mid-AAo dimensions at the level of the pulmonary arteries (Z-scores neo-aortic root: 4.38 +/- 1.96 vs. 1.52 +/- 0.70, P < 0.001; sinotubular junction: 3.48 +/- 2.67 vs. 1.38 +/- 1.30, P = 0.010; mid-AAo: 0.32 +/- 3.06 vs. 1.69 +/- 1.24, P = 0.001). FD magnitude was higher in TGA patients (neo-aortic root: 0.048 +/- 0.027 vs. 0.021 +/- 0.006, P < 0.001; sinotubular junction: 0.054 +/- 0.037 vs. 0.029 +/- 0.013, P < 0.05) and was related to the neo-aortic Z-score. Clear areas of higher WSS at the right and anterior aortic wall regions along the distal AAo were detected in TGA patients, most pronounced in those with relatively smaller mid-AAo diameters.Data Conclusion TGA-specific geometry related to the ASO, evidenced by neo-aortic root dilatation and a sudden change in vessel diameter at mid-AAo level, leads to more aortic flow asymmetry in the proximal AAo and WSS distribution with higher WSS at the right and anterior aortic wall regions along the distal AAo.Technical Efficacy Stage: 3J. Magn. Reson. Imaging 2020;51:1105-1116. Show less
BackgroundWe hypothesize that dobutamine-induced stress impacts intracardiac hemodynamic parameters and that this may be linked to decreased exercise capacity in Fontan patients. Therefore, the... Show moreBackgroundWe hypothesize that dobutamine-induced stress impacts intracardiac hemodynamic parameters and that this may be linked to decreased exercise capacity in Fontan patients. Therefore, the purpose of this study was to assess the effect of pharmacologic stress on intraventricular kinetic energy (KE), viscous energy loss (EL) and vorticity from four-dimensional (4D) Flow cardiovascular magnetic resonance (CMR) imaging in Fontan patients and to study the association between stress response and exercise capacity.MethodsTen Fontan patients underwent whole-heart 4D flow CMR before and during 7.5 mu g/kg/min dobutamine infusion and cardiopulmonary exercise testing (CPET) on the same day. Average ventricular KE, EL and vorticity were computed over systole, diastole and the total cardiac cycle (vorticity_vol(avg cycle), KEavg cycle, ELavg cycle). The relation to maximum oxygen uptake (VO2 max) from CPET was tested by Pearson's correlation or Spearman's rank correlation in case of non-normality of the data.ResultsDobutamine stress caused a significant 8852% increase in KE (KEavg cycle: 1.8 +/- 0.5 vs 3.3 +/- 0.9mJ, P<0.001), a significant 108 +/- 49% increase in EL (ELavg cycle: 0.9 +/- 0.4 vs 1.9 +/- 0.9mW, P<0.001) and a significant 27 +/- 19% increase in vorticity (vorticity_vol(avg cycle): 3441 +/- 899 vs 4394 +/- 1322mL/s, P=0.002). All rest-stress differences (%) were negatively correlated to VO2 max (KEavg cycle: r=-0.83, P=0.003; ELavg cycle: r=-0.80, P=0.006; vorticity_vol(avg cycle): r=-0.64, P=0.047).Conclusions 4D flow CMR-derived intraventricular kinetic energy, viscous energy loss and vorticity in Fontan patients increase during pharmacologic stress and show a negative correlation with exercise capacity measured by VO2 max. Show less
Aims To non-invasively assess intraventricular viscous energy loss (EL) and proportionality to kinetic energy (KE) in Fontan patients using 4D flow magnetic resonance imaging (MRI) and compare to... Show moreAims To non-invasively assess intraventricular viscous energy loss (EL) and proportionality to kinetic energy (KE) in Fontan patients using 4D flow magnetic resonance imaging (MRI) and compare to healthy controls.Methods and results Thirty Fontan patients and 15 controls underwent 4D flow MRI. Ventricular EL was computed and normalized by end-diastolic volume (EDV). EL over the cardiac cycle (ELcycle) relative to the average kinetic energy (KEcycle) was quantified using a dimensionless index, ELindex (ELcycle/KEcycle). EL was significantly elevated in Fontan patients compared to controls (ELcycle/EDV: 3.7 vs. 2.6J/m(3), P=0.001). Fontan patients with inflow of blood entering a ventricle, which leaves that ventricle through a ventricular septal defect to the aorta, defined as discordant inflow-to-outflow showed significantly higher EL compared to patients with inflow of blood into the same ventricle from which the blood is ejected into the aorta, defined as concordant inflow-to-outflow (ELcycle/EDV: 6.8 vs. 3.2J/m(3), P=0.001). EL was not significantly different in Fontan patients with a systemic left vs. a systemic right ventricle (ELcycle/EDV: 3.5 vs. 3.6J/m(3), P=0.91). ELindex was significantly elevated in Fontan patients compared to controls (ELindex: 0.4 vs. 0.2, P<0.001). Highest ELindex was found in Fontan patients with discordant inflow-to-outflow compared to concordant inflow-to-outflow (0.5 vs. 0.3, P=0.01).Conclusion Fontan patients show disproportionate intraventricular EL relative to KE. Intraventricular EL is elevated in these patients compared to healthy controls, and highest EL is found in patients with discordant inflow-to-outflow. Show less
Purpose: To compare four-dimensional flow MRI with automated valve tracking to manual valve tracking in patients with acquired or congenital heart disease and healthy volunteers.Materials and... Show morePurpose: To compare four-dimensional flow MRI with automated valve tracking to manual valve tracking in patients with acquired or congenital heart disease and healthy volunteers.Materials and Methods: In this retrospective study, data were collected from 114 patients and 46 volunteers who underwent four-dimensional flow MRI at 1.5 T or 3.0 T from 2006 through 2017. Among the 114 patients, 33 had acquired and 81 had congenital heart disease (median age, 17 years; interquartile range [IQR], 13-49 years), 51 (45%) were women, and 63 (55%) were men. Among the 46 volunteers (median age, 28 years; IQR, 22-36 years), there were 19 (41%) women and 27 (59%) men. Two orthogonal cine views of each valve were used for valve tracking. Wilcoxon signed-rank test was used to compare analysis times, net forward volumes (NFVs), and regurgitant fractions. Intra-and interobserver variability was tested by using intraclass correlation coefficients (ICCs).Results: Analysis time was shorter for automated versus manual tracking (all patients, 14 minutes [IQR, 12-15 minutes] vs 25 minutes [IQR, 20-25 minutes]; P<.001). Although overall differences in NFV and regurgitant fraction were comparable between both methods, NFV variation over four valves was smaller for automated versus manual tracking (all patients, 4.9% [IQR, 3.3%-6.7%] vs 9.8% [IQR, 5.1%-14.7%], respectively; P<.001). Regurgitation severity was discordant for seven pulmonary valves, 22 mitral valves, and 21 tricuspid valves. Intra-and interobserver agreement for automated tracking was excellent for NFV assessment (intra-and interobserver, ICC >= 0.99) and strong to excellent for regurgitant fraction assessment (intraobserver, ICC >= 0.94; interobserver, ICC >= 0.89).Conclusion: Automated valve tracking reduces analysis time and improves reliability of valvular flow quantification with four-dimensional flow MRI in patients with acquired or congenital heart disease and in healthy volunteers. (c) RSNA, 2018 Show less
Palen, R.L.F. van der; Roest, A.A.W.; Boogaard, P.J. van den; Roos, A. de; Blom, N.A.; Westenberg, J.J.M. 2018
