Browsing by Author "Botnar, Rene Michael"
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- ItemA motion-corrected deep-learning reconstruction framework for accelerating whole-heart magnetic resonance imaging in patients with congenital heart disease(Elsevier B.V., 2024) Phair, Andrew; Fotaki, Anastasia; Felsner, Lina; Fletcher, Thomas J.; Qi, Haikun; Botnar, Rene Michael; Prieto Vásquez, Claudia del CarmenBackground: Cardiovascular magnetic resonance (CMR) is an important imaging modality for the assessment and management of adult patients with congenital heart disease (CHD). However, conventional techniques for three-dimensional (3D) whole-heart acquisition involve long and unpredictable scan times and methods that accelerate scans via k-space undersampling often rely on long iterative reconstructions. Deep-learning-based reconstruction methods have recently attracted much interest due to their capacity to provide fast reconstructions while often outperforming existing state-of-the-art methods. In this study, we sought to adapt and validate a non-rigid motion-corrected model-based deep learning (MoCo-MoDL) reconstruction framework for 3D whole-heart MRI in a CHD patient cohort. Methods: The previously proposed deep-learning reconstruction framework MoCo-MoDL, which incorporates a non-rigid motion-estimation network and a denoising regularization network within an unrolled iterative reconstruction, was trained in an end-to-end manner using 39 CHD patient datasets. Once trained, the framework was evaluated in eight CHD patient datasets acquired with seven-fold prospective undersampling. Reconstruction quality was compared with the state-of-the-art non-rigid motion-corrected patch-based low-rank reconstruction method (NR-PROST) and against reference images (acquired with three-or-four-fold undersampling and reconstructed with NR-PROST). Results: Seven-fold undersampled scan times were 2.1 ± 0.3 minutes and reconstruction times were ∼30 seconds, approximately 240 times faster than an NR-PROST reconstruction. Image quality comparable to the reference images was achieved using the proposed MoCo-MoDL framework, with no statistically significant differences found in any of the assessed quantitative or qualitative image quality measures. Additionally, expert image quality scores indicated the MoCo-MoDL reconstructions were consistently of a higher quality than the NR-PROST reconstructions of the same data, with the differences in 12 of the 22 scores measured for individual vascular structures found to be statistically significant. Conclusion: The MoCo-MoDL framework was applied to an adult CHD patient cohort, achieving good quality 3D whole-heart images from ∼2-minute scans with reconstruction times of ∼30 seconds.
- ItemCorrection to: 3D SASHA myocardial T1 mapping with high accuracy and improved precision(2018) Nordio, Giovanna ; Bustin, Aurelien; Henningsson, Markus; Rashid, Imran ; Chiribiri, Amedeo ; Ismail, Tevfik ; Odille, Freddy; Prieto, Claudia; Botnar, Rene Michael
- ItemHigh-resolution automated free-breathing coronary magnetic resonance angiography in comparison with coronary computed tomography angiography(2025) Wood, Gregory; Uglebjerg Pedersen, Alexandra; Linde Nørgaard, Bjarne; Alcaraz Frederiksen, Christian; Møller Jensen, Jesper; Kunze, Karl-Philipp; Neji, Radhouene; Wetzl, Jens; Prieto Vásquez, Claudia Del Carmen; Botnar, Rene Michael; Yong Kim, WonAims Clinical implementation of coronary magnetic resonance angiography (CMRA) is limited due to variability in image quality. A protocol utilizing an image navigator (iNAV) integrated with automated scan planning has been developed to facilitate consistent diagnostic image quality. The aim of this study was to evaluate the agreement of automated iNAV CMRA compared with coronary computed tomography angiography (CCTA) using Coronary Artery Disease-Reporting and Data System (CAD-RADS) to classify coronary artery disease (CAD). Methods and results Ninety-five individuals underwent automated iNAV CMRA at a resolution of 0.7 mm3 with a deep learning–assisted automated scan planning and trigger-delay detection protocol. CMRA and CCTA data sets were analysed using CAD-RADS to classify the per-patient severity of CAD. Additionally, the accuracy of both imaging modalities in predicting referral for invasive coronary angiography (ICA) and coronary revascularization was assessed. CMRA classification for CAD-RADS ≥ 1, ≥2, ≥3, and ≥4 agreed with CCTA for 80%, 73%, 63%, and 70% of cases, respectively. The area under the receiver operating characteristic curves with CAD-RADS ≥ 4 and ≥3 for CMRA and CCTA were comparable in predicting ICA referral (0.75 vs. 0.70, P = 0.687, and 0.70 vs. 0.70, P = 0.945) and revascularization (0.72 vs. 0.74, P = 0.811, and 0.68 vs. 0.76, P = 0.089). Conclusion A novel automated iNAV CMRA protocol was implemented, investigating individuals at risk of CAD. Using the CAD-RADS classification, there was moderate to good agreement between CMRA and CCTA. In patients with CAD-RADS ≥ 4 and ≥3, CMRA was as effective as CCTA in predicting ICA referral and revascularization.
- ItemImage navigator–based, automated coronary magnetic resonance angiography for the detection of coronary artery stenosis(Elsevier B.V., 2024) Wood G.; Hajhosseiny R.; Pedersen A.U.; Littlewood S.; Hansen T.J.; Neji R.; Kunze K.P.; Wetzl J.; Norgaard B.L.; Jensen J.M.; Maeng M.; Madsen P.L.; Vejlstrup N.; Prieto C.; Botnar, Rene Michael; Kim W.Y.Coronary computed tomography angiography (CCTA) is recommended as the first-line diagnostic imaging modality in low-to-intermediate-risk individuals suspected of stable coronary artery disease (CAD). However, CCTA exposes patients to ionizing radiation and potentially nephrotoxic contrast agents. Invasive coronary angiography is the gold-standard investigation to guide coronary revascularisation strategy; however, invasive procedures incur an inherent risk to the patient. Coronary magnetic resonance angiography (CMRA) avoids these issues. Nevertheless, clinical implementation is currently limited due to extended scanning durations, inconsistent image quality, and consequent lack of diagnostic accuracy. Several technical CMRA innovations, including advanced respiratory motion correction with 100% scan efficiency (no data rejection), fast image acquisition with motion-corrected undersampled image reconstruction, and deep-learning–based automated planning, have been implemented and now await clinical validation in multi-center trials. Methods: The objective of the image navigator–based, automated CMRA prospective multi-center study is to evaluate the diagnostic accuracy of a newly developed, state-of-the-art, standardized, and automated CMRA framework compared to CCTA in 201 patients undergoing clinical investigation for CAD. The study protocol mandates the administration of oral beta-blockers to decrease heart rate to below 60 bpm and the use of sublingual nitroglycerine spray to induce vasodilation. Additionally, the study incorporates the utilization of standardized postprocessing with sliding-thin-slab multiplanar reformatting, in combination with evaluation of the source images, to optimize the visualization of coronary artery stenosis. Discussion: If proven effective, CMRA could provide a non-invasive, needle-free, yet also clinically viable, alternative to CCTA. Trial Registration: This study is registered at ClinicalTrials.gov (NCT05473117).
- ItemImaging Methods: Magnetic Resonance Imaging(Lippincott Williams and Wilkins, 2023) Thomas, Katharine E.; Ferreira, Vanessa M.; Fotaki, Anastasia; Botnar, Rene Michael© 2022 American Heart Association, Inc.Myocardial inflammation occurs following activation of the cardiac immune system, producing characteristic changes in the myocardial tissue. Cardiovascular magnetic resonance is the non-invasive imaging gold standard for myocardial tissue characterization, and is able to detect image signal changes that may occur resulting from inflammation, including edema, hyperemia, capillary leak, necrosis, and fibrosis. Conventional cardiovascular magnetic resonance for the detection of myocardial inflammation and its sequela include T2-weighted imaging, parametric T1- and T2-mapping, and gadolinium-based contrast-enhanced imaging. Emerging techniques seek to image several parameters simultaneously for myocardial tissue characterization, and to depict subtle immune-mediated changes, such as immune cell activity in the myocardium and cardiac cell metabolism. This review article outlines the underlying principles of current and emerging cardiovascular magnetic resonance methods for imaging myocardial inflammation.
- ItemIsotropic, high-resolution, whole-chest inversion recovery contrast-enhanced magnetic resonance angiography in under 4.5 min using image-based navigator fluoro trigger(2025) Craft, Jason; Parikh, Roosha; Cheng, Josh Y.; Diaz, Nancy; Kunze, Karl P.; Schmidt, Michaela; Neji, Radhouene; Leung, Amanda; Weber, Suzanne; Weber, Jonathan; Carter, Timothy; Biso, Sylvia; Yamashita, Ann-Marie; Wolff, Eric H.; Prieto Vásquez, Claudia Del Carmen; Botnar, Rene MichaelBACKGROUND: Serial assessment of the thoracic aorta with magnetic resonance angiography (MRA) is desirable due to 3D volumetric dataset, high spatial resolution, and lack of ionizing radiation. Electrocardiogram (ECG) gated, contrast-enhanced (CE), inversion recovery gradient echo MRA is efficient and historically provides low artifact burden, but the window for imaging with weak albumin binding extracellular gadolinium based contrast agents is small. Our purpose was to acquire whole-chest gated CE-MRA with 1.2 mm 3 resolution using image-based navigator (iNAV) for motion correction/contrast monitoring, and variable density sampling in 4-5 min. Image quality and vessel diameter reproducibility are assessed against time resolved MRA (TR-MRA). METHODS: iNAV CE-MRA and TR-MRA were obtained prospectively in 40 patients and reviewed by 3 blinded cardiologists for vessel diameter and image quality rated on a four point scale: (1) non-diagnostic; (2) poor-significant blurring; (3) good-mild blurring; and (4) excellent. Reproducibility and image quality were evaluated using the concordance correlation statistic and Cohen's kappa with mean differences evaluated using paired t-tests and repeat-measures ANOVA. RESULTS: iNAV CE-MRA scan time was 4.2 ± 0.7 min. iNAV CE-MRA quality score was higher ( p
- ItemMolecular MR-Imaging for Noninvasive Quantification of the Anti-Inflammatory Effect of Targeting Interleukin-1β in a Mouse Model of Aortic Aneurysm(SAGE Publications Inc., 2020) Brangsch, Julia; Reimann, Carolin; Kaufmann, Jan Ole; Adams, Lisa Christine; Hamm, Bernd; Makowski, Marcus Richard; Thöne-Reineke, Christa; Wilke, Marco; Weller, Michael; Onthank, David; Robinson, Simon; Buchholz, Rebecca; Karst, Uwe; Botnar, Rene MichaelMolecular-MRI is a promising imaging modality for the assessment of abdominal aortic aneurysms (AAAs). Interleukin-1β (IL-1β) represents a new therapeutic tool for AAA-treatment, since pro-inflammatory cytokines are key-mediators of inflammation. This study investigates the potential of molecular-MRI to evaluate therapeutic effects of an anti-IL-1β-therapy on AAA-formation in a mouse-model. Methods: Osmotic-minipumps were implanted in apolipoprotein-deficient-mice (N = 27). One group (Ang-II+01BSUR group, n = 9) was infused with angiotensin-II (Ang-II) for 4 weeks and received an anti-murine IL-1β-antibody (01BSUR) 3 times. One group (Ang-II-group, n = 9) was infused with Ang-II for 4 weeks but received no treatment. Control-group (n = 9) was infused with saline and received no treatment. MR-imaging was performed using an elastin-specific gadolinium-based-probe (0.2 mmol/kg). Results: Mice of the Ang-II+01BSUR-group showed a lower aortic-diameter compared to mice of the Ang-II-group and control mice (p < 0.05). Using the elastin-specific-probe, a significant decrease in elastin-destruction was observed in mice of the Ang-II+01BSUR-group. In vivo MR-measurements correlated well with histopathology (y = 0.34x-13.81, R2 = 0.84, p < 0.05), ICP-MS (y = 0.02x+2.39; R2 = 0.81, p < 0.05) and LA-ICP-MS. Immunofluorescence and western-blotting confirmed a reduced IL-1β-expression. Conclusions: Molecular-MRI enables the early visualization and quantification of the anti-inflammatory-effects of an IL-1β-inhibitor in a mouse-model of AAAs. Responders and non-responders could be identified early after the initiation of the therapy using molecular-MRI.
- ItemNon-rigid motion-corrected free-breathing 3D myocardial Dixon LGE imaging in a clinical setting(SPRINGER, 2022) Zeilinger, Martin Georg; Kunze, Karl Philipp; Munoz, Camila; Neji, Radhouene; Schmidt, Michaela; Croisille, Pierre; Heiss, Rafael; Wuest, Wolfgang; Uder, Michael; Botnar, Rene Michael; Treutlein, Christoph; Prieto, ClaudiaObjectives To investigate the efficacy of an in-line non-rigid motion-compensated reconstruction (NRC) in an image-navigated high-resolution three-dimensional late gadolinium enhancement (LGE) sequence with Dixon water-fat separation, in a clinical setting. Methods Forty-seven consecutive patients were enrolled prospectively and examined with 1.5 T MRI. NRC reconstructions were compared to translational motion-compensated reconstructions (TC) of the same datasets in overall and different sub-category image quality scores, diagnostic confidence, contrast ratios, LGE pattern, and semiautomatic LGE quantification. Results NRC outperformed TC in all image quality scores (p < 0.001 to 0.016; e.g., overall image quality 5/5 points vs. 4/5). Overall image quality was downgraded in only 23% of NRC datasets vs. 53% of TC datasets due to residual respiratory motion. In both reconstructions, LGE was rated as ischemic in 11 patients and non-ischemic in 10 patients, while it was absent in 26 patients. NRC delivered significantly higher LGE-to-myocardium and blood-to-myocardium contrast ratios (median 6.33 vs. 5.96, p < 0.001 and 4.88 vs. 4.66, p < 0.001, respectively). Automatically detected LGE mass was significantly lower in the NRC reconstruction (p < 0.001). Diagnostic confidence was identical in all cases, with high confidence in 89% and probable in 11% datasets for both reconstructions. No case was rated as inconclusive. Conclusions The in-line implementation of a non-rigid motion-compensated reconstruction framework improved image quality in image-navigated free-breathing, isotropic high-resolution 3D LGE imaging with undersampled spiral-like Cartesian sampling and Dixon water-fat separation compared to translational motion correction of the same datasets. The sharper depictions of LGE may lead to more accurate measures of LGE mass.