Browsing by Author "Greil, Gerald F."

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    Assesment of cardiac volumes in children with congenital heart disease using a 3D dual cardiac phase technique and a new segmentation tool
    (2010) Hussain, Tarique; Bellsham-Revell, Hannah.; Uribe Arancibia, Sergio A.; Bell, Aaron.; Razavi, Reza; Beerbaum, Philipp B.; Valverde, Isra.; Schaeffter, Tobias; Greil, Gerald F.
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    Combined coronary lumen and vessel wall magnetic resonance imaging with i-T2prep : influence of nitroglycerin
    (2015) Hussain, Tarique; Henningsson, Markus; Butzbach, Britta; Lossnitzer, Dirk; Greil, Gerald F.; Andía Kohnenkampf, Marcelo Edgardo; Botnar, René Michael
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    Congenital Heart Disease in Children: Coronary MR Angiography during Systole and Diastole with Dual Cardiac Phase Whole-Heart Imaging
    (RADIOLOGICAL SOC NORTH AMERICA, 2011) Uribe, Sergio; Hussain, Tarique; Valverde, Israel; Tejos, Cristian; Irarrazaval, Pablo; Fava, Mario; Beerbaum, Philipp; Botnar, Rene M.; Razavi, Reza; Schaeffter, Tobias; Greil, Gerald F.
    Purpose: To assess the optimal timing for coronary magnetic resonance (MR) angiography in children with congenital heart disease by using dual cardiac phase whole-heart MR imaging.
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    Contrast-enhanced magnetic resonance imaging for the detection of ruptured coronary plaques in patients with acute myocardial infarction
    (2017) Jansen, Christian H. P.; Perera, Divaka; Wiethoff, Andrea J.; Phinikaridou, Alkystis; Razavi, Reza M.; Rinaldi, Aldo; Marber, Mike S.; Greil, Gerald F.; Nagel, Eike; Botnar, René Michael; Maintz, David; Redwood, Simon; Makowski, Marcus
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    Dual-phase whole-heart imaging using image navigation in congenital heart disease
    (2018) Botnar, René Michael; Moyé, Danielle M.; Hussain, Tarique.; Tandon, Animesh.; Greil, Gerald F.; Dyer, Adrian K.; Henningsson, Markus.
    Abstract Background Dual-phase 3-dimensional whole-heart acquisition allows simultaneous imaging during systole and diastole. Respiratory navigator gating and tracking of the diaphragm is used with limited accuracy. Prolonged scan time is common, and navigation often fails in patients with erratic breathing. Image-navigation (iNAV) tracks movement of the heart itself and is feasible in single phase whole heart imaging. To evaluate its diagnostic ability in congenital heart disease, we sought to apply iNAV to dual-phase sequencing. Methods Healthy volunteers and patients with congenital heart disease underwent dual-phase imaging using the conventional diaphragmatic-navigation (dNAV) and iNAV. Acquisition time was recorded and image quality assessed. Sharpness and length of the right coronary (RCA), left anterior descending (LAD), and circumflex (LCx) arteries were measured in both cardiac phases for both approaches. Qualitative and quantitative analyses were performed in a blinded and randomized fashion. Results In volunteers, there was no significant difference in vessel sharpness between approaches (p > 0.05). In patients, analysis showed equal vessel sharpness for LAD and RCA (p > 0.05). LCx sharpness was greater with dNAV (p < 0.05). Visualized length with iNAV was 0.5 ± 0.4 cm greater than that with dNAV for LCx in diastole (p < 0.05), 1.0 ± 0.3 cm greater than dNAV for LAD in diastole (p < 0.05), and 0.8 ± 0.7 cm greater than dNAV for RCA in systole (p < 0.05). Qualitative scores were similar between modalities (p = 0.71). Mean iNAV scan time was 5:18 ± 2:12 min shorter than mean dNAV scan time in volunteers (p = 0.0001) and 3:16 ± 1:12 min shorter in patients (p = 0.0001). Conclusions Image quality of iNAV and dNAV was similar with better distal vessel visualization with iNAV. iNAV acquisition time was significantly shorter. Complete cardiac diagnosis was achieved. Shortened acquisition time will improve clinical applicability and patient comfort.
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    Flow-sensitive four-dimensional magnetic resonance imaging facilitates the quantitative analysis of systemic-to-pulmonary collateral flow in patients with univentricular hearts
    (2012) Uribe Arancibia, Sergio A.; Nordmeyer, Sarah; Valverde, Israel; Greil, Gerald F.; Berger, Felix; Kuehne, Titus; Beerbaum, Philipp B.
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    Improved coronary magnetic resonance angiography using gadobenate dimeglumine in pediatric congenital heart disease
    (2018) Silva Vieira, Miguel; Henningsson, Markus; Dedieu, Nathalie; Vassiliou, Vassilios S.; Bell, Aaron; Mathur, Sujeev; Pushparajah, Kuberan; Figueroa, Carlos Alberto; Hussain, Tarique; Botnar, René Michael; Greil, Gerald F.
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    Pressure gradient prediction in aortic coarctation using a computational-fluid-dynamics model: validation against invasive pressure catheterization at rest and pharmacological stress
    (2015) Sotelo Parraguez, Julio Andrés; Valverde, Israel.; Beerbaum, Philipp B.; Greil, Gerald F.; Schaeffter, Tobias.; Razavi, Reza.; Hurtado Sepúlveda, Daniel; Uribe Arancibia, Sergio A.; Figueroa, Carlos A.
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    Single breath-hold assessment of cardiac function using an accelerated 3D single breath-hold acquisition technique - comparison of an intravascular and extravascular contrast agent
    (2012) Makowski, Marcus R.; Wiethoff, Andrea J.; Jansen, Christian H.; Uribe Arancibia, Sergio A.; Parish, Victoria.; Schuster, Andreas.; Botnar, René Michael; Bell, Aaron.; Kiesewetter, Christoph.; Razavi, Reza.; Schaeffter, Tobias.; Greil, Gerald F.
    Abstract Background Cardiovascular magnetic resonance (CMR) is the current gold standard for the assessment of left ventricular (LV) function. Repeated breath-holds are needed for standard multi-slice 2D cine steady-state free precession sequences (M2D-SSFP). Accelerated single breath-hold techniques suffer from low contrast between blood pool and myocardium. In this study an intravascular contrast agent was prospectively compared to an extravascular contrast agent for the assessment of LV function using a single-breath-hold 3D-whole-heart cine SSFP sequence (3D-SSFP). Methods LV function was assessed in fourteen patients on a 1.5 T MR-scanner (Philips Healthcare) using 32-channel coil technology. Patients were investigated twice using a 3D-SSFP sequence (acquisition time 18–25 s) after Gadopentetate dimeglumine (GdD, day 1) and Gadofosveset trisodium (GdT, day 2) administration. Image acquisition was accelerated using sensitivity encoding in both phase encoding directions (4xSENSE). CNR and BMC were both measured between blood and myocardium. The CNR incorporated noise measurements, while the BMC represented the coeffiancy between the signal from blood and myocardium [1]. Contrast to noise ratio (CNR), blood to myocardium contrast (BMC), image quality, LV functional parameters and intra-/interobserver variability were compared. A M2D-SSFP sequence was used as a reference standard on both days. Results All 3D-SSFP sequences were successfully acquired within one breath-hold after GdD and GdT administration. CNR and BMC were significantly (p < 0.05) higher using GdT compared to GdD, resulting in an improved endocardial definition. Using 3D-SSFP with GdT, Bland–Altman plots showed a smaller bias (95% confidence interval LVEF: 9.0 vs. 23.7) and regression analysis showed a stronger correlation to the reference standard (R2 = 0.92 vs. R2 = 0.71), compared to 3D-SSFP with GdD. Conclusions A single-breath-hold 3D-whole-heart cine SSFP sequence in combination with 32-channel technology and an intravascular contrast agent allows for the accurate and fast assessment of LV function. Trial registration The study was approved by the local research ethics committee (Study No. 07/Q0704/2) and was registered with the Medicines and Healthcare Products Regulatory Agency (MHRA Study No. 28482/0002/001–0001, EudraCTnumber 2006–007042).
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    Systemic-to-pulmonary collateral flow in patients with palliated univentricular heart physiology: measurement using cardiovascular magnetic resonance 4D velocity acquisition
    (2012) Valverde, Israel.; Uribe Arancibia, Sergio A.; Nordmeyer, Sarah.; Greil, Gerald F.; Berger, Felix.; Kuehne, Titus.; Beerbaum, Philipp B.
    Abstract Background Systemic-to-pulmonary collateral flow (SPCF) may constitute a risk factor for increased morbidity and mortality in patients with single-ventricle physiology (SV). However, clinical research is limited by the complexity of multi-vessel two-dimensional (2D) cardiovascular magnetic resonance (CMR) flow measurements. We sought to validate four-dimensional (4D) velocity acquisition sequence for concise quantification of SPCF and flow distribution in patients with SV. Methods 29 patients with SV physiology prospectively underwent CMR (1.5 T) (n = 14 bidirectional cavopulmonary connection [BCPC], age 2.9 ± 1.3 years; and n = 15 Fontan, 14.4 ± 5.9 years) and 20 healthy volunteers (age, 28.7 ± 13.1 years) served as controls. A single whole-heart 4D velocity acquisition and five 2D flow acquisitions were performed in the aorta, superior/inferior caval veins, right/left pulmonary arteries to serve as gold-standard. The five 2D velocity acquisition measurements were compared with 4D velocity acquisition for validation of individual vessel flow quantification and time efficiency. The SPCF was calculated by evaluating the disparity between systemic (aortic minus caval vein flows) and pulmonary flows (arterial and venour return). The pulmonary right to left and the systemic lower to upper body flow distribution were also calculated. Results The comparison between 4D velocity and 2D flow acquisitions showed good Bland-Altman agreement for all individual vessels (mean bias, 0.05±0.24 l/min/m2), calculated SPCF (−0.02±0.18 l/min/m2) and significantly shorter 4D velocity acquisition-time (12:34 min/17:28 min,p < 0.01). 4D velocity acquisition in patients versus controls revealed (1) good agreement between systemic versus pulmonary estimator for SPFC; (2) significant SPCF in patients (BCPC 0.79±0.45 l/min/m2; Fontan 0.62±0.82 l/min/m2) and not in controls (0.01 + 0.16 l/min/m2), (3) inverse relation of right/left pulmonary artery perfusion and right/left SPCF (Pearson = −0.47,p = 0.01) and (4) upper to lower body flow distribution trend related to the weight (r = 0.742, p < 0.001) similar to the controls. Conclusions 4D velocity acquisition is reliable, operator-independent and more time-efficient than 2D flow acquisition to quantify SPCF. There is considerable SPCF in BCPC and Fontan patients. SPCF was more pronounced towards the respective lung with less pulmonary arterial flow suggesting more collateral flow where less anterograde branch pulmonary artery perfusion.