scholarly journals A novel approach to determine aortic valve area with phase-contrast cardiovascular magnetic resonance

2022 ◽  
Vol 24 (1) ◽  
Author(s):  
Felix Troger ◽  
Ivan Lechner ◽  
Martin Reindl ◽  
Christina Tiller ◽  
Magdalena Holzknecht ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aortic Valve ◽  
Phase Contrast ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Aortic Valve Area ◽  
Novel Approach ◽  
Valve Area

Abstract Background Transthoracic echocardiography (TTE) is the diagnostic routine standard for assessing aortic stenosis (AS). However, its inaccuracies in determining stroke volume (SV) and aortic valve area (AVA) call for a more precise and dependable method. Phase-contrast cardiovascular magnetic resonance imaging (PC-CMR) is a promising tool to push these boundaries. Thus, the aim of this study was to validate a novel approach based on PC-CMR against the gold-standard of invasive determination of AVA in AS compared to TTE. Methods A total of 50 patients with moderate or severe AS underwent TTE, cardiac catheterization and CMR. AVA via PC-CMR was determined by plotting momentary flow across the valve against flow-velocity. SV by CMR was measured directly via PC-CMR and volumetrically using cine-images. Invasive SV and AVA were determined via Fick-principle and Gorlin-formula, respectively. TTE yielded SV and AVA using continuity equation. Gradients were calculated via the modified Bernoulli-equation. Results SV by PC-CMR (85 ± 31 ml) correlated strongly (r: 0.73, p < 0.001) with cine-CMR (85 ± 19 ml) without significant bias (lower and upper limits of agreement (LLoA and ULoA): − 41 ml and 44 ml, p = 0.83). In PC-CMR, mean pressure gradient correlated significantly with invasive determination (r: 0.36, p = 0.011). Mean AVA, as determined by PC-CMR during systole (0.78 ± 0.25 cm2), correlated moderately (r: 0.54, p < 0.001) with invasive AVA (0.70 ± 0.23 cm2), resulting in a small bias of 0.08 cm2 (LLoA and ULoA: − 0.36 cm2 and 0.55 cm2, p = 0.017). Inter-methodically, AVA by TTE (0.81 ± 0.23 cm2) compared to invasive determination showed similar correlations (r: 0.58, p < 0.001 with a bias of 0.11 cm2, LLoA and ULoA: − 0.30 and 0.52, p < 0.001) to PC-CMR. Intra- and interobserver reproducibility were excellent for AVA (intraclass-correlation-coefficients of 0.939 and 0.827, respectively). Conclusions Our novel approach using continuous determination of flow-volumes and velocities with PC-CMR enables simple AVA measurement with no bias to invasive assessment. This approach highlights non-invasive AS grading through CMR, especially when TTE findings are inconclusive.

scholarly journals Invasive validation of a novel approach to determine aortic valve area with phase-contrast cardiac magnetic resonance imaging

2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
F Troger ◽  
I Lechner ◽  
M Reindl ◽  
C Tiller ◽  
M Holzknecht ◽  
...  
Keyword(s):  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aortic Valve ◽  
Phase Contrast ◽  
Low Flow ◽  
Aortic Valve Area ◽  
Novel Approach ◽  
Valve Area ◽  
Flow States

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Society of Cardiology Background. Echocardiography is considered the standard method for screening and diagnosing aortic valve stenosis. However, inaccuracies in the determination of stroke-volumes by the continuity equation might particularly make the evaluation of patients with low-flow states difficult. Phase-contrast cardiac magnetic resonance (PC-CMR) is a promising tool in overcoming these limitations by the simultaneous determination of flow volumes and velocities across the stenotic valve. Purpose The aim of this study is to validate a novel approach based on PC-CMR against the invasive determination of the aortic valve area (AVA). Methods. PC-CMR was performed in 50 patients with moderate or severe AS (n = 52; age 72 years [interquartile range (IQR) 66 - 78], 38% of patients with low-flow states). All of them were referred to invasive evaluation of aortic stenosis by cardiac catheterization. Additionally, transthoracic echocardiography (TTE) was performed. Aortic valve area (AVA) was determined by PC-CMR (AVAPC-CMR) via plotting momentary flow across the valve against momentary flow velocity. AVAPC-CMR at different time points over the entire cardiac cycle was compared to invasively determined AVA, calculated according to the Gorlin-formula. Stroke volumes (SV) were determined by the Fick-principle, pressure gradients according to the modified Bernoulli-equation. Results. Mean AVA during the whole systolic phase showed a good correlation (r: 0.544, p &lt; 0.001) with invasive AVA with a small bias (AVACMR: 0.78 cm², IQR: [0.60-0.96] versus AVAINVASIVE: 0.70 cm², IQR: [0.52-0.87], bias: 0.08 cm², p = 0.017). Intermethodical correlation and bias of AVA as measured by TTE (AVATTE) and AVAINVASIVE were similar to AVAPC-CMR (AVATTE: 0.81 cm²; IQR: [0.64-0.96] versus AVAINVASIVE: 0.70 cm², IQR: [0.52-0.87] r: 0.580, p &lt; 0.001, bias 0.11 cm², p &lt; 0.001). SV by PC-CMR showed a good correlation with Cine-CMR with no significant bias (r: 0.730, p &lt; 0.001; SVPC-CMR: 86 ± 31 ml; SVCine: 85 ± 19 ml). Maximum gradients determined by PC‑CMR were 65 ± 2 9mmHg and showed a good inverse correlation with AVAPC-CMR (r: ‑0.371; p = 0.008). Conclusion. PC-CMR with continuous determination of flow volumes and flow velocities is able to determine AVA in patients with severe aortic stenosis with a tendency to overestimate AVA compared to invasively determined AVA.

scholarly journals Aortic stenosis reexpanded – a novel approach to determine aortic valve area with phase contrast cardiovascular magnetic resonance imaging

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
F Troger ◽  
I Lechner ◽  
M Reindl ◽  
C Tiller ◽  
M Holzknecht ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiovascular Magnetic Resonance ◽  
Cardiovascular Magnetic Resonance Imaging ◽  
Phase Contrast ◽  
Aortic Valve Area ◽  
Resonance Imaging ◽  
Novel Approach ◽  
Cine Cmr ◽  
Valve Area

Abstract Background Transthoracic echocardiography (TTE) has become the diagnostic standard for evaluating aortic stenosis (AS) severity, mainly because of its advantages in comparison to the gold standard of cardiac catheterization. However, its inaccuracies in determining stroke volume (SV) and consequentially computing aortic valve area (AVA) call for a more precise and dependable method. Phase contrast cardiovascular magnetic resonance imaging (PC-CMR) is an aspiring tool to push these boundaries. Purpose The aim of this study was to validate a novel and simple approach based on PC-CMR against the invasive and echocardiographic determination of SV and AVA in patients with moderate and severe AS. Methods A total of 50 patients with moderate or severe AS underwent TTE, cardiac catheterization and CMR; AVA by PC-CMR was determined via plotting momentary flow across the valve against momentary flow velocity. SV via CMR was measured directly via PC-CMR and volumetrically using cine images. Invasive SV and AVA were determined via Fick principle and Gorlin formula, respectively. TTE yielded SV and AVA using the continuity equation. Finally, gradients were calculated via the modified Bernoulli equation. Results SV by PC-CMR showed a strong correlation with cine-CMR with no significant bias (r: 0.730, p&lt;0.001; SV by PC-CMR: 85±31ml; SV by cine-CMR: 85±19ml, p=0.829). Peak gradients determined by PC-CMR were 65±29mmHg and correlated inversely with AVA by PC-CMR (r: −0.371; p=0.008). Mean AVA during the whole systolic phase showed a moderate correlation (r: 0.544, p&lt;0.001) to invasive AVA with a small bias (AVA by CMR: 0.78±0.25cm2 versus invasive AVA: 0.70±0.23cm2, bias: 0.08cm2, p=0.017). Inter-methodical correlation and bias of AVA as measured by TTE and invasive AVA (AVA by TTE: 0.81±0.23cm2, r: 0.580, p&lt;0.001, bias 0.11cm2, p&lt;0.001) were similar to AVA by PC-CMR and invasive AVA. Conclusion PC-CMR provides a great option to yield reliable and solid SV values in patients with moderate and severe AS. Furthermore, continuous determination of flow volumes and flow velocities is able to determine AVA in these patients in an easy and reproducible manner. Our novel approach shines a light on the diagnostic potential of PC-CMR for non-invasive AS grading, especially in cases where echocardiography reaches its limits and where clinical findings appear inconclusive. FUNDunding Acknowledgement Type of funding sources: None. Central Illustration Cine (l,r) and PC-CMR (m) images in AS

3-T magnetic resonance for determination of aortic valve area: A comparison to echocardiography

2014 ◽  
Vol 48 (3) ◽  
pp. 176-183 ◽  
Author(s):  
Uwe Speiser ◽  
Silvio Quick ◽  
David Haas ◽  
Akram Youssef ◽  
Nadine K. Waessnig ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Aortic Valve ◽  
Aortic Valve Area ◽  
Valve Area

scholarly journals P349 Utility and prognostic value of aortic valve area by magnetic resonance imaging in patients with aortic stenosis

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
B Igual Munoz ◽  
O B H Oscar Blanco Herrera ◽  
F J V M Francisco Jose Valera Martinez ◽  
D D V Diana Domingo Valero ◽  
P S S Pilar Sepulveda Sanchez ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Aortic Valve ◽  
Aortic Stenosis ◽  
Ejection Fraction ◽  
Prognostic Value ◽  
Phase Contrast ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Aortic Valve Area ◽  
Valve Area

Abstract Classically clinical evaluation of patients with aortic stenosis (AS) is made using clinical and echocardiographic parameters but recently new imaging techniques as cardiovascular magnetic resonance (CMR ) are being used increasingly in this clinical setting. We aim to assess utility and prognostic value of aortic valve area (AVA) by CMR in patients with AS regarding echocardiographic data. METHODS a retrospective cohort of patients with AS referred to CMR and cardiac echocardiography study for evaluation were included. Patients with known coronary artery disease or another significant valve disease were excluded. Clinical Follow up was performed to asses cardiovascular death, hospital admission or aortic valve replacement at the first year after imaging evaluation. Furthermore symptomatic status was assessed. Echocardiographic severity was estimated used peak and mean gradients . Additionally a CMR study including b-SSFPS for left ventricle ejection fraction (LVEF) quantification and phase-contrast sequences acquired at aortic valve plane to analyze aortic valve area (AVA) by planimetry was performed. RESULTS ninety eight patients, mean age 67+ 15 years, 52(58%) males, 23 (25%) with decreased left ventricular ejection fraction. A significant negative correlation was observed between AVA by CMR and echocardiographic gradients ( -0.49 for mean gradient and -0.58 for peak gradient). AVA was strongly associated to symptomatic status (AUROC curve 0.66, p &lt; 0.001). A multivariate logistic regression model including echocardiographic gradients,CMR, LVEF and AVA was performed and mean gradient ( OR:1.02 p = 0.01) and AVA (OR: 0.002 p = 0.001) were shown to be independent predictors of events. Conclusion 1.AVA by planimetry in phase-contrast CMR sequences is a valid tool to asses severity of aortic valve stenosis . 2 AVA was strongly associated to symptomatic status.3. AVA has proven to have additional prognostic value beyond echocardiographic gradients. Abstract P349 Figure. Aortic valve area by planimetry by MR

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