المؤلفون: Elsayed, Ayah, Mauger, Charlène, Ferdian, Edward, Gilbert, Kathleen, Scadeng, Miriam, Occleshaw, Christopher, Lowe, Boris, McCulloch, Andrew, Omens, Jeffrey, Govil, Sachin, Pushparajah, Kuberan, Young, Alistair

مصطلحات موضوعية: 4D flow, atlas, shape, tetralogy of Fallot, vorticity

الوصف: Remodeling in adults with repaired tetralogy of Fallot (rToF) may occur due to chronic pulmonary regurgitation, but may also be related to altered flow patterns, including vortices. We aimed to correlate and quantify relationships between vorticity and ventricular shape derived from atlas-based analysis of biventricular shape. Adult rToF (n = 12) patients underwent 4D flow and cine MRI imaging. Vorticity in the RV was computed after noise reduction using a neural network. A biventricular shape atlas built from 95 rToF patients was used to derive principal component modes, which were associated with vorticity and pulmonary regurgitant volume (PRV) using univariate and multivariate linear regression. Univariate analysis showed that indexed PRV correlated with 3 modes (r = -0.55,-0.50, and 0.6, all p < 0.05) associated with RV dilatation and an increase in basal bulging, apical bulging and tricuspid annulus tilting with more severe regurgitation, as well as a smaller LV and paradoxical movement of the septum. RV outflow and inflow vorticity were also correlated with these modes. However, total vorticity over the whole RV was correlated with two different modes (r = -0.62,-0.69, both p < 0.05). Higher vorticity was associated with both RV and LV shape changes including longer ventricular length, a larger bulge beside the tricuspid valve, and distinct tricuspid tilting. RV flow vorticity was associated with changes in biventricular geometry, distinct from associations with PRV. Flow vorticity may provide additional mechanistic information in rToF remodeling. Both LV and RV shapes are important in rToF RV flow patterns.

وصف الملف: application/pdf

الوصول الحر: https://escholarship.org/uc/item/3323358cTest

المؤلفون: Zhao, Debbie, Ferdian, Edward, Maso Talou, Gonzalo D, Quill, Gina M, Gilbert, Kathleen, Wang, Vicky Y, Babarenda Gamage, Thiranja P, Pedrosa, João, D'hooge, Jan, Sutton, Timothy M, Lowe, Boris S, Legget, Malcolm E, Ruygrok, Peter N, Doughty, Robert N, Camara, Oscar, Young, Alistair A, Nash, Martyn P

مصطلحات موضوعية: 3D echocardiography (3DE), Cardiac Atlas Project, cardiac magnetic resonance (CMR) imaging, domain adaptation, left ventricle (LV), machine learning (ML), multimodal imaging, segmentation (image processing), Clinical Research, Cardiovascular, Biomedical Imaging, Bioengineering, Heart Disease

جغرافية الموضوع: Switzerland

الوصف: Segmentation of the left ventricle (LV) in echocardiography is an important task for the quantification of volume and mass in heart disease. Continuing advances in echocardiography have extended imaging capabilities into the 3D domain, subsequently overcoming the geometric assumptions associated with conventional 2D acquisitions. Nevertheless, the analysis of 3D echocardiography (3DE) poses several challenges associated with limited spatial resolution, poor contrast-to-noise ratio, complex noise characteristics, and image anisotropy. To develop automated methods for 3DE analysis, a sufficiently large, labeled dataset is typically required. However, ground truth segmentations have historically been difficult to obtain due to the high inter-observer variability associated with manual analysis. We address this lack of expert consensus by registering labels derived from higher-resolution subject-specific cardiac magnetic resonance (CMR) images, producing 536 annotated 3DE images from 143 human subjects (10 of which were excluded). This heterogeneous population consists of healthy controls and patients with cardiac disease, across a range of demographics. To demonstrate the utility of such a dataset, a state-of-the-art, self-configuring deep learning network for semantic segmentation was employed for automated 3DE analysis. Using the proposed dataset for training, the network produced measurement biases of -9 ± 16 ml, -1 ± 10 ml, -2 ± 5 %, and 5 ± 23 g, for end-diastolic volume, end-systolic volume, ejection fraction, and mass, respectively, outperforming an expert human observer in terms of accuracy as well as scan-rescan reproducibility. As part of the Cardiac Atlas Project, we present here a large, publicly available 3DE dataset with ground truth labels that leverage the higher resolution and contrast of CMR, to provide a new benchmark for automated 3DE analysis. Such an approach not only reduces the effect of observer-specific bias present in manual 3DE annotations, but also enables the development of analysis ...

وصف الملف: Electronic-eCollection; application/pdf

العلاقة: Frontiers in cardiovascular medicine; (2022). Frontiers in Cardiovascular Medicine, 9, 1016703-.; https://hdl.handle.net/2292/63327Test; 36704465 (pubmed)

الإتاحة: https://doi.org/10.3389/fcvm.2022.1016703Test
https://hdl.handle.net/2292/63327Test

المؤلفون: Zhao, Debbie, Mauger, Charlène A, Gilbert, Kathleen, Wang, Vicky Y, Quill, Gina M, Sutton, Timothy M, Lowe, Boris S, Legget, Malcolm E, Ruygrok, Peter N, Doughty, Robert N, Pedrosa, João, D'hooge, Jan, Young, Alistair A, Nash, Martyn P

مصطلحات موضوعية: Heart Ventricles, Humans, Echocardiography, Three-Dimensional, Magnetic Resonance Imaging, Stroke Volume, Reproducibility of Results, Ventricular Function, Left, Bias, 32 Biomedical and Clinical Sciences, 40 Engineering, 4003 Biomedical Engineering, Cardiovascular, Biomedical Imaging, Clinical Research, Heart Disease, Science & Technology, Multidisciplinary Sciences, Science & Technology - Other Topics, LEAST-SQUARES REGRESSION, LEFT-VENTRICULAR MASS, HEALTHY-SUBJECTS, MOTION ATLAS, HEART, TRACKING, VOLUME, SHAPE, MR, SEGMENTATION

جغرافية الموضوع: England

الوصف: Cardiovascular imaging studies provide a multitude of structural and functional data to better understand disease mechanisms. While pooling data across studies enables more powerful and broader applications, performing quantitative comparisons across datasets with varying acquisition or analysis methods is problematic due to inherent measurement biases specific to each protocol. We show how dynamic time warping and partial least squares regression can be applied to effectively map between left ventricular geometries derived from different imaging modalities and analysis protocols to account for such differences. To demonstrate this method, paired real-time 3D echocardiography (3DE) and cardiac magnetic resonance (CMR) sequences from 138 subjects were used to construct a mapping function between the two modalities to correct for biases in left ventricular clinical cardiac indices, as well as regional shape. Leave-one-out cross-validation revealed a significant reduction in mean bias, narrower limits of agreement, and higher intraclass correlation coefficients for all functional indices between CMR and 3DE geometries after spatiotemporal mapping. Meanwhile, average root mean squared errors between surface coordinates of 3DE and CMR geometries across the cardiac cycle decreased from 7 ± 1 to 4 ± 1 mm for the total study population. Our generalised method for mapping between time-varying cardiac geometries obtained using different acquisition and analysis protocols enables the pooling of data between modalities and the potential for smaller studies to leverage large population databases for quantitative comparisons.

وصف الملف: Electronic; application/pdf

العلاقة: Scientific reports; (2023). Scientific Reports, 13(1), 8118-.; https://hdl.handle.net/2292/66467Test; 37208380 (pubmed)

الإتاحة: https://doi.org/10.1038/s41598-023-33968-5Test
https://hdl.handle.net/2292/66467Test

المؤلفون: Zhao, Debbie, Mauger, Charlène A., Gilbert, Kathleen, Wang, Vicky Y., Quill, Gina M., Sutton, Timothy M., Lowe, Boris S., Legget, Malcolm E., Ruygrok, Peter N., Doughty, Robert N., Pedrosa, João, D’hooge, Jan, Young, Alistair A., Nash, Martyn P.

المصدر: Scientific Reports ; volume 13, issue 1 ; ISSN 2045-2322

مصطلحات موضوعية: Multidisciplinary

الإتاحة: https://doi.org/10.1038/s41598-023-40773-7Test
https://www.nature.com/articles/s41598-023-40773-7.pdfTest
https://www.nature.com/articles/s41598-023-40773-7Test

المؤلفون: Dillon, Joshua R., Zhao, Debbie, Gamage, Thiranja P. Babarenda, Quill, Gina M., Wang, Vicky Y., Edwards, Nicola C., Sutton, Timothy M., Lowe, Boris S., Legget, Malcolm E., Doughty, Robert N., Young, Alistair A., Nash, Martyn P.

المصدر: Statistical Atlases and Computational Models of the Heart. Regular and CMRxRecon Challenge Papers ; Lecture Notes in Computer Science ; page 119-129 ; ISSN 0302-9743 1611-3349 ; ISBN 9783031524479 9783031524486

الإتاحة: https://doi.org/10.1007/978-3-031-52448-6_12Test

المؤلفون: Creamer, Stephen A., Zhao, Debbie, Quill, Gina M., Hasaballa, Abdallah I., Wang, Vicky Y., Gamage, Thiranja P. Babarenda, Edwards, Nicola C., Legget, Malcolm E., Lowe, Boris S., Doughty, Robert N., Arri, Satpal, Ruygrok, Peter N., Young, Alistair A., Paton, Julian F. R., Talou, Gonzalo D. Maso, Nash, Martyn P.

المصدر: Statistical Atlases and Computational Models of the Heart. Regular and CMRxRecon Challenge Papers ; Lecture Notes in Computer Science ; page 108-118 ; ISSN 0302-9743 1611-3349 ; ISBN 9783031524479 9783031524486

الإتاحة: https://doi.org/10.1007/978-3-031-52448-6_11Test

المؤلفون: Elsayed, Ayah, Mauger, Charlène a., Ferdian, Edward, Gilbert, Kathleen, Scadeng, Miriam, Occleshaw, Christopher J., Lowe, Boris S., Mcculloch, Andrew D., Omens, Jeffrey H., Govil, Sachin, Pushparajah, Kuberan, Young, Alistair A.

المصدر: Elsayed , A , Mauger , C A , Ferdian , E , Gilbert , K , Scadeng , M , Occleshaw , C J , Lowe , B S , Mcculloch , A D , Omens , J H , Govil , S , Pushparajah , K & Young , A A 2022 , ' Right Ventricular Flow Vorticity Relationships with Biventricular Shape in Adult Tetralogy of Fallot ' , Frontiers in Cardiovascular Medicine , vol. 8 . https://doi.org/10.3389/fcvm.2021.806107Test

الوصف: Remodelling in adults with repaired tetralogy of Fallot (rToF) may occur due to chronic pulmonary regurgitation, but may also be related to altered flow patterns, including vortices. We aimed to correlate and quantify relationships between vorticity and ventricular shape derived from atlas-based analysis of biventricular shape. Adult rToF (n=12) patients underwent 4D flow and cine MRI imaging. Vorticity in the RV was computed after noise reduction using a neural network. A biventricular shape atlas built from 95 rToF patients was used to derive principal component modes, which were associated with vorticity and pulmonary regurgitant volume (PRV) using univariate and multivariate linear regression. Univariate analysis showed that indexed PRV correlated with 3 modes (r = -0.55, -0.50 and 0.6, all p<0.05) associated with RV dilatation and an increase in basal bulging, apical bulging and tricuspid annulus tilting with more severe regurgitation, as well as a smaller LV and paradoxical movement of the septum. RV outflow and inflow vorticity were also correlated with these modes. However, total vorticity over the whole RV was correlated with two different modes (r = -0.62, -0.69, both p<0.05). Higher vorticity was associated with both RV and LV shape changes including longer ventricular length, a larger bulge beside the tricuspid valve, and distinct tricuspid tilting. RV flow vorticity was associated with changes in biventricular geometry, distinct from associations with PRV. Flow vorticity may provide additional mechanistic information in rToF remodeling. Both LV and RV shapes are important in rToF RV flow patterns

الإتاحة: https://doi.org/10.3389/fcvm.2021.806107Test
https://kclpure.kcl.ac.uk/portal/en/publications/199ee31d-c060-48ed-ae25-d33dbbd94601Test

المؤلفون: Lydiard, Suzanne, Pontré, Beau, Lowe, Boris S., Keall, Paul

المساهمون: Auckland Academic Health Alliance, University of Sydney

المصدر: Physical and Engineering Sciences in Medicine ; volume 45, issue 3, page 757-767 ; ISSN 2662-4729 2662-4737

مصطلحات موضوعية: Radiology, Nuclear Medicine and imaging, Instrumentation, Biomedical Engineering, Biophysics, Radiological and Ultrasound Technology, Biotechnology

الوصف: Magnetic resonance imaging (MRI) guided cardiac radioablation (CR) for atrial fibrillation (AF) is a promising treatment concept. However, the visibility of AF CR targets on MRI acquisitions requires further exploration and MRI sequence and parameter optimization has not yet been performed for this application. This pilot study explores the feasibility of MRI-guided tracking of AF CR targets by evaluating AF CR target visualization on human participants using a selection of 3D and 2D MRI sequences.MRI datasets were acquired in healthy and AF participants using a range of MRI sequences and parameters. MRI acquisition categories included 3D free-breathing acquisitions ( 3D acq ), 2D breath-hold ECG-gated acquisitions ( 2D ECG-gated ), stacks of 2D breath-hold ECG-gated acquisitions which were retrospectively interpolated to 3D datasets ( 3D interp ), and 2D breath-hold ungated acquisitions ( 2D real-time ). The ease of target delineation and the presence of artifacts were qualitatively analyzed. Image quality was quantitatively analyzed using signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and non-uniformity. Confident 3D target delineation was achievable on all 3D interp datasets but was not possible on any of the 3D acq datasets. Fewer artifacts and significantly better SNR, CNR and non-uniformity metrics were observed with 3D interp compared to 3D acq . 2D real-time datasets had slightly lower SNR and CNR than 2D ECG-gated and 3D interp n datasets. AF CR target visualization on MRI was qualitatively and quantitatively evaluated. The study findings indicate that AF CR target visualization is achievable despite the imaging challenges associated with these targets, warranting further investigation into MRI-guided AF CR treatments.

الإتاحة: https://doi.org/10.1007/s13246-022-01141-3Test

المؤلفون: Lydiard, Suzanne, Pontré, Beau, Lowe, Boris S., Ball, Helen, Sasso, Giuseppe, Keall, Paul

المصدر: Medical Physics ; volume 48, issue 3, page 931-941 ; ISSN 0094-2405 2473-4209

الوصف: Purpose The safe delivery of cardiac radioablation (CR) for atrial fibrillation (AF) is challenged by multi‐direction target motion, cardiac rate variability, target proximity to critical structures, and the importance of complete target dose coverage for therapeutic benefit. Careful selection of appropriate treatment procedures is therefore essential. This work characterizes AF cardiac radioablation target motion and target proximity to surrounding structures in both healthy and AF participants to guide optimal treatment technique and technology choice. Methods Ten healthy participants and five participants with AF underwent MRI acquisition. Multi‐slice, cardiac‐gated, breath‐hold cines were acquired and interpolated to create three‐dimensional images for 18–30 cardiac phases. Treatment targets at the left and right pulmonary vein ostia (CTV Left and CTV Right respectively) and adjacent cardiac structures were contoured and their displacements throughout the cardiac cycle were assessed. Target proximity to surrounding structures were measured. Free‐breathing real‐time two‐dimensional cine images were also acquired at 4 Hz frequency for between 1‐ and 2‐min duration. The motion of easily identifiable points within the target, diaphragm and sternum was measured to assess respiratory motion. Results Target motion due to cardiac contraction was most prominent in the medial‐lateral direction and of 4–5 mm magnitude. CTV Right displacements were smaller in participants with AF than healthy participants in normal sinus rhythm. Nearby cardiac structures often moved with different magnitudes and motion trajectories. CTV Left and/or CTV Right were in direct contact with the esophagus in 73% of participants. Target motion due to respiration was most prominent in the superior–inferior direction and of 13–14 mm magnitude in both healthy and AF participants. Conclusion AF CR target motion and relative displacement was characterized. The combination of target motion magnitude and relative displacement to critical structures ...

الإتاحة: https://doi.org/10.1002/mp.14661Test

المؤلفون: Turaga, Mansi, Kerr, Andrew, Looi, Jen Li, Lowe, Boris, Lydon, Anna, Occleshaw, Chris, Weeks, Phil, Young, Alistair, Gabriel, Ruvin

المصدر: Heart, Lung and Circulation ; volume 26, page S31-S32 ; ISSN 1443-9506

مصطلحات موضوعية: Cardiology and Cardiovascular Medicine, Pulmonary and Respiratory Medicine

الإتاحة: https://doi.org/10.1016/j.hlc.2017.05.080Test
https://api.elsevier.com/content/article/PII:S1443950617304249?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S1443950617304249?httpAccept=text/plainTest