1
|
Phair A, Fotaki A, Felsner L, Fletcher TJ, Qi H, Botnar RM, Prieto C. A motion-corrected deep-learning reconstruction framework for accelerating whole-heart magnetic resonance imaging in patients with congenital heart disease. J Cardiovasc Magn Reson 2024; 26:101039. [PMID: 38521391 PMCID: PMC10993190 DOI: 10.1016/j.jocmr.2024.101039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/16/2024] [Accepted: 03/14/2024] [Indexed: 03/25/2024] Open
Abstract
BACKGROUND 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.
Collapse
Affiliation(s)
- Andrew Phair
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Anastasia Fotaki
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Lina Felsner
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Thomas J Fletcher
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Haikun Qi
- School of Biomedical Engineering, Shanghai Tech University, Shanghai, China
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Instituto de Ingeniería Biológica y Médica, Pontificia Universidad Católica de Chile, Santiago, Chile; Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Institute for Intelligent Healthcare Engineering, Santiago, Chile; Technical University of Munich, Institute of Advanced Study, Munich, Germany
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile; Millennium Institute for Intelligent Healthcare Engineering, Santiago, Chile.
| |
Collapse
|
2
|
Koundinyan SP, Baron CA, Malavé MO, Ong F, Addy NO, Cheng JY, Yang PC, Hu BS, Nishimura DG. High-resolution, respiratory-resolved coronary MRA using a Phyllotaxis-reordered variable-density 3D cones trajectory. Magn Reson Imaging 2023; 98:140-148. [PMID: 36646397 PMCID: PMC9991864 DOI: 10.1016/j.mri.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/10/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
PURPOSE To develop a respiratory-resolved motion-compensation method for free-breathing, high-resolution coronary magnetic resonance angiography (CMRA) using a 3D cones trajectory. METHODS To achieve respiratory-resolved 0.98 mm resolution images in a clinically relevant scan time, we undersample the imaging data with a variable-density 3D cones trajectory. For retrospective motion compensation, translational estimates from 3D image-based navigators (3D iNAVs) are used to bin the imaging data into four phases from end-expiration to end-inspiration. To ensure pseudo-random undersampling within each respiratory phase, we devise a phyllotaxis readout ordering scheme mindful of eddy current artifacts in steady state free precession imaging. Following binning, residual 3D translational motion within each phase is computed using the 3D iNAVs and corrected for in the imaging data. The noise-like aliasing characteristic of the combined phyllotaxis and cones sampling pattern is leveraged in a compressed sensing reconstruction with spatial and temporal regularization to reduce aliasing in each of the respiratory phases. RESULTS In initial studies of six subjects, respiratory motion compensation using the proposed method yields improved image quality compared to non-respiratory-resolved approaches with no motion correction and with 3D translational correction. Qualitative assessment by two cardiologists and quantitative evaluation with the image edge profile acutance metric indicate the superior sharpness of coronary segments reconstructed with the proposed method (P < 0.01). CONCLUSION We have demonstrated a new method for free-breathing, high-resolution CMRA based on a variable-density 3D cones trajectory with modified phyllotaxis ordering and respiratory-resolved motion compensation with 3D iNAVs.
Collapse
Affiliation(s)
| | - Corey A Baron
- Medical Biophysics, Western University, London, Ontario, Canada
| | - Mario O Malavé
- Electrical Engineering, Stanford University, Stanford, CA, United States
| | - Frank Ong
- Electrical Engineering, Stanford University, Stanford, CA, United States
| | - Nii Okai Addy
- Electrical Engineering, Stanford University, Stanford, CA, United States
| | - Joseph Y Cheng
- Electrical Engineering, Stanford University, Stanford, CA, United States; Radiology, Stanford University, Stanford, CA, United States
| | - Phillip C Yang
- Cardiovascular Medicine, Stanford University, Stanford, CA, United States
| | - Bob S Hu
- Electrical Engineering, Stanford University, Stanford, CA, United States; Cardiology, Palo Alto Medical Foundation, Palo Alto, CA, United States
| | - Dwight G Nishimura
- Electrical Engineering, Stanford University, Stanford, CA, United States.
| |
Collapse
|
3
|
Optimization in the space domain for density compensation with the nonuniform FFT. Magn Reson Imaging 2023; 100:102-111. [PMID: 36934830 DOI: 10.1016/j.mri.2023.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 03/02/2023] [Accepted: 03/12/2023] [Indexed: 03/19/2023]
Abstract
The non-uniform Discrete Fourier Transform algorithm has shown great utility for reconstructing images from non-uniformly spaced samples in the Fourier domain in several imaging modalities. Due to the non-uniform spacing, some correction for the variable density of the samples must be made. Common methods for generating density compensation values are either sub-optimal or only consider a finite set of points in the optimization. This manuscript presents an algorithm for generating density compensation values from a set of Fourier samples that takes into account the point spread function over an entire rectangular region in the image domain. We show that the reconstructed images using the density compensation values of this method are of superior quality when compared to other standard methods. Results are shown with a numerical phantom and with magnetic resonance images of the abdomen and the knee.
Collapse
|
4
|
Ismail TF, Strugnell W, Coletti C, Božić-Iven M, Weingärtner S, Hammernik K, Correia T, Küstner T. Cardiac MR: From Theory to Practice. Front Cardiovasc Med 2022; 9:826283. [PMID: 35310962 PMCID: PMC8927633 DOI: 10.3389/fcvm.2022.826283] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/17/2022] [Indexed: 01/10/2023] Open
Abstract
Cardiovascular disease (CVD) is the leading single cause of morbidity and mortality, causing over 17. 9 million deaths worldwide per year with associated costs of over $800 billion. Improving prevention, diagnosis, and treatment of CVD is therefore a global priority. Cardiovascular magnetic resonance (CMR) has emerged as a clinically important technique for the assessment of cardiovascular anatomy, function, perfusion, and viability. However, diversity and complexity of imaging, reconstruction and analysis methods pose some limitations to the widespread use of CMR. Especially in view of recent developments in the field of machine learning that provide novel solutions to address existing problems, it is necessary to bridge the gap between the clinical and scientific communities. This review covers five essential aspects of CMR to provide a comprehensive overview ranging from CVDs to CMR pulse sequence design, acquisition protocols, motion handling, image reconstruction and quantitative analysis of the obtained data. (1) The basic MR physics of CMR is introduced. Basic pulse sequence building blocks that are commonly used in CMR imaging are presented. Sequences containing these building blocks are formed for parametric mapping and functional imaging techniques. Commonly perceived artifacts and potential countermeasures are discussed for these methods. (2) CMR methods for identifying CVDs are illustrated. Basic anatomy and functional processes are described to understand the cardiac pathologies and how they can be captured by CMR imaging. (3) The planning and conduct of a complete CMR exam which is targeted for the respective pathology is shown. Building blocks are illustrated to create an efficient and patient-centered workflow. Further strategies to cope with challenging patients are discussed. (4) Imaging acceleration and reconstruction techniques are presented that enable acquisition of spatial, temporal, and parametric dynamics of the cardiac cycle. The handling of respiratory and cardiac motion strategies as well as their integration into the reconstruction processes is showcased. (5) Recent advances on deep learning-based reconstructions for this purpose are summarized. Furthermore, an overview of novel deep learning image segmentation and analysis methods is provided with a focus on automatic, fast and reliable extraction of biomarkers and parameters of clinical relevance.
Collapse
Affiliation(s)
- Tevfik F. Ismail
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Cardiology Department, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Wendy Strugnell
- Queensland X-Ray, Mater Hospital Brisbane, Brisbane, QLD, Australia
| | - Chiara Coletti
- Magnetic Resonance Systems Lab, Delft University of Technology, Delft, Netherlands
| | - Maša Božić-Iven
- Magnetic Resonance Systems Lab, Delft University of Technology, Delft, Netherlands
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | | | - Kerstin Hammernik
- Lab for AI in Medicine, Technical University of Munich, Munich, Germany
- Department of Computing, Imperial College London, London, United Kingdom
| | - Teresa Correia
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Centre of Marine Sciences, Faro, Portugal
| | - Thomas Küstner
- Medical Image and Data Analysis (MIDAS.lab), Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Tübingen, Germany
| |
Collapse
|
5
|
Bardo DME, Rubert N. Radial sequences and compressed sensing in pediatric body magnetic resonance imaging. Pediatr Radiol 2022; 52:382-390. [PMID: 34009408 DOI: 10.1007/s00247-021-05097-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 03/11/2021] [Accepted: 04/28/2021] [Indexed: 12/28/2022]
Abstract
Magnetic resonance imaging (MRI) is often an ideal imaging modality for children of any age for any anatomy and for many pathologies. MRI sequences can be prescribed to produce high-resolution images of anatomical structures, characterize tissue composition, and detect physiological states and organ function. Shortening imaging sequences in any manner possible has been a topic of research and development in MRI since its emergence. Selection of imaging sequence parameters influences more than just the appearance and signal qualities of the imaged tissues; these details along with spatial encoding and data readout steps determine the time it takes to acquire an image. As each piece of image data is acquired and encoded with spatial and temporal information it is stored in k-space. As k-space is filled, either completely or partially, a diagnostic image or physiological data can be reconstructed. Shortening the length of time required for the readout step by efficiently filling k-space using compressed sensing and radial techniques is the subject of this manuscript.
Collapse
Affiliation(s)
- Dianna M E Bardo
- Phoenix Children's Hospital, 1919 E. Thomas Road, Phoenix, AZ, 85016, USA.
| | - Nicholas Rubert
- Phoenix Children's Hospital, 1919 E. Thomas Road, Phoenix, AZ, 85016, USA
| |
Collapse
|
6
|
Schneider A, Cruz G, Munoz C, Hajhosseiny R, Kuestner T, Kunze KP, Neji R, Botnar RM, Prieto C. Whole-heart non-rigid motion corrected coronary MRA with autofocus virtual 3D iNAV. Magn Reson Imaging 2022; 87:169-176. [PMID: 34999163 DOI: 10.1016/j.mri.2022.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/04/2022] [Indexed: 01/21/2023]
Abstract
PURPOSE Respiratory motion-corrected coronary MR angiography (CMRA) has shown promise for assessing coronary disease. By incorporating coronal 2D image navigators (iNAVs), respiratory motion can be corrected for in a beat-to-beat basis using translational correction in the foot-head (FH) and right-left (RL) directions and in a bin-to-bin basis using non-rigid motion correction addressing the remaining FH, RL and anterior-posterior (AP) motion. However, with this approach beat-to-beat AP motion is not corrected for. In this work we investigate the effect of remaining beat-to-beat AP motion and propose a virtual 3D iNAV that exploits autofocus motion correction to enable beat-to-beat AP and improved RL intra-bin motion correction. METHODS Free-breathing 3D whole-heart CMRA was acquired using a 3-fold undersampled variable-density Cartesian trajectory. Beat-to-beat 3D translational respiratory motion was estimated from the 2D iNAVs in FH and RL directions, and in AP direction with autofocus assuming a linear relationship between FH and AP movement of the heart. Furthermore, motion in RL was also refined using autofocus. This virtual 3D (v3D) iNAV was incorporated in a non-rigid motion correction (NRMC) framework. The proposed approach was tested in 12 cardiac patients, and visible vessel length and vessel sharpness for the right (RCA) and left (LAD) coronary arteries were compared against 2D iNAV-based NRMC. RESULTS Average vessel sharpness and length in v3D iNAV NRMC was improved compared to 2D iNAV NRMC (vessel sharpness: RCA: 56 ± 1% vs 52 ± 11%, LAD: 49 ± 8% vs 49 ± 7%; visible vessel length: RCA: 5.98 ± 1.37 cm vs 5.81 ± 1.62 cm, LAD: 5.95 ± 1.85 cm vs 4.83 ± 1.56 cm), however these improvements were not statistically significant. CONCLUSION The proposed virtual 3D iNAV NRMC reconstruction further improved NRMC CMRA image quality by reducing artefacts arising from residual AP motion, however the level of improvement was subject-dependent.
Collapse
Affiliation(s)
- Alina Schneider
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.
| | - Gastao Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Camila Munoz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Reza Hajhosseiny
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Thomas Kuestner
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Medical Image and Data Analysis, Department of Interventional and Diagnostic Radiology, University Hospital of Tübingen, Tübingen, Germany
| | - Karl P Kunze
- MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
7
|
Qi H, Hajhosseiny R, Cruz G, Kuestner T, Kunze K, Neji R, Botnar R, Prieto C. End-to-end deep learning nonrigid motion-corrected reconstruction for highly accelerated free-breathing coronary MRA. Magn Reson Med 2021; 86:1983-1996. [PMID: 34096095 DOI: 10.1002/mrm.28851] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 03/22/2021] [Accepted: 04/29/2021] [Indexed: 12/26/2022]
Abstract
PURPOSE To develop an end-to-end deep learning technique for nonrigid motion-corrected (MoCo) reconstruction of ninefold undersampled free-breathing whole-heart coronary MRA (CMRA). METHODS A novel deep learning framework was developed consisting of a diffeomorphic registration network and a motion-informed model-based deep learning (MoDL) reconstruction network. The registration network receives as input highly undersampled (~22×) respiratory-resolved images and outputs 3D nonrigid respiratory motion fields between the images. The motion-informed MoDL performs MoCo reconstruction from undersampled data using the predicted motion fields. The whole deep learning framework, termed as MoCo-MoDL, was trained end-to-end in a supervised manner for simultaneous 3D nonrigid motion estimation and MoCo reconstruction. MoCo-MoDL was compared with a state-of-the-art nonrigid MoCo CMRA reconstruction technique in 15 retrospectively undersampled datasets and 9 prospectively undersampled acquisitions. RESULTS The acquisition time for ninefold accelerated CMRA was ~2.5 min. The reconstruction time was ~22 s for the proposed MoCo-MoDL and ~35 min for the conventional approach. MoCo-MoDL achieved higher peak SNR (27.86 ± 3.00 vs. 26.71 ± 2.79; P < .05) and structural similarity (0.78 ± 0.06 vs. 0.75 ± 0.06; P < .05) than the conventional approach. Similar vessel length and visual image quality score were obtained with the 2 methods, whereas improved vessel sharpness was observed with MoCo-MoDL. CONCLUSION An end-to-end deep learning approach was introduced for simultaneous nonrigid motion estimation and MoCo reconstruction of highly undersampled free-breathing whole-heart CMRA. The rapid free-breathing CMRA acquisition together with the fast reconstruction of the proposed approach promises easy integration into clinical workflow.
Collapse
Affiliation(s)
- Haikun Qi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- School of Biomedical Engineering, ShanghaiTech University, Shanghai, People's Republic of China
| | - Reza Hajhosseiny
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Gastao Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Thomas Kuestner
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Medical Image and Data Analysis, Department of Interventional and Diagnostic Radiology, University Hospital of Tübingen, Tübingen, Germany
| | - Karl Kunze
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - René Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
8
|
Hajhosseiny R, Munoz C, Cruz G, Khamis R, Kim WY, Prieto C, Botnar RM. Coronary Magnetic Resonance Angiography in Chronic Coronary Syndromes. Front Cardiovasc Med 2021; 8:682924. [PMID: 34485397 PMCID: PMC8416045 DOI: 10.3389/fcvm.2021.682924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 07/23/2021] [Indexed: 01/14/2023] Open
Abstract
Cardiovascular disease is the leading cause of mortality worldwide, with atherosclerotic coronary artery disease (CAD) accounting for the majority of cases. X-ray coronary angiography and computed tomography coronary angiography (CCTA) are the imaging modalities of choice for the assessment of CAD. However, the use of ionising radiation and iodinated contrast agents remain drawbacks. There is therefore a clinical need for an alternative modality for the early identification and longitudinal monitoring of CAD without these associated drawbacks. Coronary magnetic resonance angiography (CMRA) could be a potential alternative for the detection and monitoring of coronary arterial stenosis, without exposing patients to ionising radiation or iodinated contrast agents. Further advantages include its versatility, excellent soft tissue characterisation and suitability for repeat imaging. Despite the early promise of CMRA, widespread clinical utilisation remains limited due to long and unpredictable scan times, onerous scan planning, lower spatial resolution, as well as motion related image quality degradation. The past decade has brought about a resurgence in CMRA technology, with significant leaps in image acceleration, respiratory and cardiac motion estimation and advanced motion corrected or motion-resolved image reconstruction. With the advent of artificial intelligence, great advances are also seen in deep learning-based motion estimation, undersampled and super-resolution reconstruction promising further improvements of CMRA. This has enabled high spatial resolution (1 mm isotropic), 3D whole heart CMRA in a clinically feasible and reliable acquisition time of under 10 min. Furthermore, latest super-resolution image reconstruction approaches which are currently under evaluation promise acquisitions as short as 1 min. In this review, we will explore the recent technological advances that are designed to bring CMRA closer to clinical reality.
Collapse
Affiliation(s)
- Reza Hajhosseiny
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Camila Munoz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Gastao Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Ramzi Khamis
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Won Yong Kim
- Department of Cardiology and Institute of Clinical Medicine, Aarhus University Hospital, Skejby, Denmark
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Escuela de Ingeniería, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - René M. Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
- Escuela de Ingeniería, Pontificia Universidad Catolica de Chile, Santiago, Chile
- Instituto de Ingeniería Biologica y Medica, Pontificia Universidad Catolica de Chile, Santiago, Chile
| |
Collapse
|
9
|
Kobayashi N. Magnetic resonance imaging with gradient sound respiration guide. PLoS One 2021; 16:e0254758. [PMID: 34280236 PMCID: PMC8289037 DOI: 10.1371/journal.pone.0254758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 07/03/2021] [Indexed: 12/31/2022] Open
Abstract
Respiratory motion management is crucial for high-resolution MRI of the heart, lung, liver and kidney. In this article, respiration guide using acoustic sound generated by pulsed gradient waveforms was introduced in the pulmonary ultrashort echo time (UTE) sequence and validated by comparing with retrospective respiratory gating techniques. The validated sound-guided respiration was implemented in non-contrast enhanced renal angiography. In the sound-guided respiration, breathe−in and–out instruction sounds were generated with sinusoidal gradient waveforms with two different frequencies (602 and 321 Hz). Performance of the sound-guided respiration was evaluated by measuring sharpness of the lung-liver interface with a 10–90% rise distance, w10-90, and compared with three respiratory motion managements in a free-breathing UTE scan: without respiratory gating (w/o gating), 0-dimensional k-space navigator (k-point navigator), and image-based self-gating (Img-SG). The sound-guided respiration was implemented in stack-of-stars balanced steady-state free precession with inversion recovery preparation for renal angiography. No subjects reported any discomfort or inconvenience with the sound-guided respiration in pulmonary or renal MRI scans. The lung-liver interface of the UTE images for sound-guided respiration (w10-90 = 6.99 ± 2.90 mm), k-point navigator (8.51 ± 2.71 mm), and Img-SG (7.01 ± 2.06 mm) was significantly sharper than that for w/o gating (17.13 ± 2.91 mm; p < 0.0001 for all of sound-guided respiration, k-point navigator and Img-SG). Sharpness of the lung-liver interface was comparable between sound-guided respiration and Img-SG (p = 0.99), but sound-guided respiration achieved better visualization of pulmonary vasculature. Renal angiography with the sound-guided respiration clearly delineated renal, segmental and interlobar arteries. In conclusion, the gradient sound guided respiration can facilitate a consistent diaphragm position in every breath and achieve performance of respiratory motion management comparable to image-based self-gating.
Collapse
Affiliation(s)
- Naoharu Kobayashi
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States of America
- * E-mail:
| |
Collapse
|
10
|
Roy CW, Heerfordt J, Piccini D, Rossi G, Pavon AG, Schwitter J, Stuber M. Motion compensated whole-heart coronary cardiovascular magnetic resonance angiography using focused navigation (fNAV). J Cardiovasc Magn Reson 2021; 23:33. [PMID: 33775246 PMCID: PMC8006382 DOI: 10.1186/s12968-021-00717-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 01/28/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Radial self-navigated (RSN) whole-heart coronary cardiovascular magnetic resonance angiography (CCMRA) is a free-breathing technique that estimates and corrects for respiratory motion. However, RSN has been limited to a 1D rigid correction which is often insufficient for patients with complex respiratory patterns. The goal of this work is therefore to improve the robustness and quality of 3D radial CCMRA by incorporating both 3D motion information and nonrigid intra-acquisition correction of the data into a framework called focused navigation (fNAV). METHODS We applied fNAV to 500 data sets from a numerical simulation, 22 healthy subjects, and 549 cardiac patients. In each of these cohorts we compared fNAV to RSN and respiratory resolved extradimensional golden-angle radial sparse parallel (XD-GRASP) reconstructions of the same data. Reconstruction times for each method were recorded. Motion estimate accuracy was measured as the correlation between fNAV and ground truth for simulations, and fNAV and image registration for in vivo data. Percent vessel sharpness was measured in all simulated data sets and healthy subjects, and a subset of patients. Finally, subjective image quality analysis was performed by a blinded expert reviewer who chose the best image for each in vivo data set and scored on a Likert scale 0-4 in a subset of patients by two reviewers in consensus. RESULTS The reconstruction time for fNAV images was significantly higher than RSN (6.1 ± 2.1 min vs 1.4 ± 0.3, min, p < 0.025) but significantly lower than XD-GRASP (25.6 ± 7.1, min, p < 0.025). Overall, there is high correlation between the fNAV and reference displacement estimates across all data sets (0.73 ± 0.29). For simulated data, healthy subjects, and patients, fNAV lead to significantly sharper coronary arteries than all other reconstruction methods (p < 0.01). Finally, in a blinded evaluation by an expert reviewer fNAV was chosen as the best image in 444 out of 571 data sets (78%; p < 0.001) and consensus grades of fNAV images (2.6 ± 0.6) were significantly higher (p < 0.05) than uncorrected (1.7 ± 0.7), RSN (1.9 ± 0.6), and XD-GRASP (1.8 ± 0.8). CONCLUSION fNAV is a promising technique for improving the quality of RSN free-breathing 3D whole-heart CCMRA. This novel approach to respiratory self-navigation can derive 3D nonrigid motion estimations from an acquired 1D signal yielding statistically significant improvement in image sharpness relative to 1D translational correction as well as XD-GRASP reconstructions. Further study of the diagnostic impact of this technique is therefore warranted to evaluate its full clinical utility.
Collapse
Affiliation(s)
- Christopher W Roy
- Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue de Bugnon 46, BH-7-84, 1011, Lausanne, Switzerland.
| | - John Heerfordt
- Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue de Bugnon 46, BH-7-84, 1011, Lausanne, Switzerland
- Advanced Clinical Imaging Technology (ACIT), Siemens Healthcare AG, Lausanne, Switzerland
| | - Davide Piccini
- Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue de Bugnon 46, BH-7-84, 1011, Lausanne, Switzerland
- Advanced Clinical Imaging Technology (ACIT), Siemens Healthcare AG, Lausanne, Switzerland
| | - Giulia Rossi
- Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue de Bugnon 46, BH-7-84, 1011, Lausanne, Switzerland
| | - Anna Giulia Pavon
- Division of Cardiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Juerg Schwitter
- Division of Cardiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Director CMR-Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Faculty of Biology and Medicine, University of Lausanne (UNIL), Lausanne, Switzerland
| | - Matthias Stuber
- Department of Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Rue de Bugnon 46, BH-7-84, 1011, Lausanne, Switzerland
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland
| |
Collapse
|
11
|
Qi H, Fuin N, Cruz G, Pan J, Kuestner T, Bustin A, Botnar RM, Prieto C. Non-Rigid Respiratory Motion Estimation of Whole-Heart Coronary MR Images Using Unsupervised Deep Learning. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:444-454. [PMID: 33021937 DOI: 10.1109/tmi.2020.3029205] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Non-rigid motion-corrected reconstruction has been proposed to account for the complex motion of the heart in free-breathing 3D coronary magnetic resonance angiography (CMRA). This reconstruction framework requires efficient and accurate estimation of non-rigid motion fields from undersampled images at different respiratory positions (or bins). However, state-of-the-art registration methods can be time-consuming. This article presents a novel unsupervised deep learning-based strategy for fast estimation of inter-bin 3D non-rigid respiratory motion fields for motion-corrected free-breathing CMRA. The proposed 3D respiratory motion estimation network (RespME-net) is trained as a deep encoder-decoder network, taking pairs of 3D image patches extracted from CMRA volumes as input and outputting the motion field between image patches. Using image warping by the estimated motion field, a loss function that imposes image similarity and motion smoothness is adopted to enable training without ground truth motion field. RespME-net is trained patch-wise to circumvent the challenges of training a 3D network volume-wise which requires large amounts of GPU memory and 3D datasets. We perform 5-fold cross-validation with 45 CMRA datasets and demonstrate that RespME-net can predict 3D non-rigid motion fields with subpixel accuracy (0.44 ± 0.38 mm) within ~10 seconds, being ~20 times faster than a GPU-implemented state-of-the-art non-rigid registration method. Moreover, we perform non-rigid motion-compensated CMRA reconstruction for 9 additional patients. The proposed RespME-net has achieved similar motion-corrected CMRA image quality to the conventional registration method regarding coronary artery length and sharpness.
Collapse
|
12
|
Hajhosseiny R, Bustin A, Munoz C, Rashid I, Cruz G, Manning WJ, Prieto C, Botnar RM. Coronary Magnetic Resonance Angiography: Technical Innovations Leading Us to the Promised Land? JACC Cardiovasc Imaging 2020; 13:2653-2672. [PMID: 32199836 DOI: 10.1016/j.jcmg.2020.01.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 02/07/2023]
Abstract
Coronary artery disease remains the leading cause of cardiovascular morbidity and mortality. Invasive X-ray angiography and coronary computed tomography angiography are established gold standards for coronary luminography. However, they expose patients to invasive complications, ionizing radiation, and iodinated contrast agents. Among a number of imaging modalities, coronary cardiovascular magnetic resonance (CMR) angiography may be used in some cases as an alternative for the detection and monitoring of coronary arterial stenosis, with advantages including its versatility, excellent soft tissue characterization, and avoidance of ionizing radiation and iodinated contrast agents. In this review, we explore the recent advances in motion correction, image acceleration, and reconstruction technologies that are bringing coronary CMR angiography closer to widespread clinical implementation.
Collapse
Affiliation(s)
- Reza Hajhosseiny
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; National Heart and Lung Institute, Imperial College London, London, United Kingdom.
| | - Aurelien Bustin
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Camila Munoz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Imran Rashid
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Gastao Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Warren J Manning
- Department of Medicine (Cardiovascular Division) and Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Escuela de Ingeniería, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Escuela de Ingeniería, Pontificia Universidad Catolica de Chile, Santiago, Chile
| |
Collapse
|
13
|
Characterization of Uterine Motion in Early Gestation Using MRI-Based Motion Tracking. Diagnostics (Basel) 2020; 10:diagnostics10100840. [PMID: 33086473 PMCID: PMC7603139 DOI: 10.3390/diagnostics10100840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/25/2020] [Accepted: 10/15/2020] [Indexed: 11/17/2022] Open
Abstract
Magnetic resonance imaging (MRI) is a promising non-invasive imaging technique that can be safely used to study placental development and function. However, studies of the human placenta performed by MRI are limited by uterine motion and motion in the uterus during MRI remains one of the major limiting factors. Here, we aimed to investigate the characterization of uterine activity during MRI in the second trimester of pregnancy using MRI-based motion tracking. In total, 46 pregnant women were scanned twice (first scan between 14 and 18 weeks and second scan between 19 and 24 weeks), and 20 pregnant subjects underwent a single MRI between 14 and 18 weeks GA, resulting in 112 MRI scans. An MRI-based algorithm was used to track uterine motion in the superior-inferior and left-right directions. Uterine contraction and maternal motion cases were separated by the experts, and unpaired Wilcoxon tests were performed within the groups of gestational age (GA), fetal sex, and placental location in terms of the overall intensity measures of the uterine activity. In total, 22.3% of cases had uterine contraction during MRI, which increased from 18.6% at 14–18 weeks to 26.4% at 19–24 weeks GA. The dominant direction of the uterine contraction and maternal motion was the superior to the inferior direction during early gestation.
Collapse
|
14
|
Stobbe RW, Beaulieu C. Three-dimensional Yarnball k-space acquisition for accelerated MRI. Magn Reson Med 2020; 85:1840-1854. [PMID: 33009872 DOI: 10.1002/mrm.28536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/20/2020] [Accepted: 09/08/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE To introduce an efficient sampling technique named Yarnball, which may serve as a direct alternative to 3D Cones. METHODS Yarnball evolves through 3D k-space with increasing loop size, and the differential equations defining this flexible trajectory are presented in detail. The sampling efficiencies of Yarnball and 3D Cones were compared through point spread function analysis and simulated imaging (which highlights undersampling in the absence of other scanning effects). The feasibility of Yarnball implementation was demonstrated for fully sampled T1 -weighted images of the human head at 3 T. RESULTS The mostly large 3D loops of the Yarnball trajectory facilitate rapid sampling under peripheral nerve stimulation constraint, an advantage that increases with readout duration (TRO ). Point spread function analysis yielded 89% (TRO = 2 ms) and 77% (TRO = 10 ms) of Yarnball voxels with magnitude less than 0.01% of the point spread function peak. For 3D Cones, these values were only 52% and 29%. The 3D-Cones technique required 1.4 times (TRO = 2 ms) and 1.8 times (TRO = 10 ms) more trajectories than Yarnball to produce simulated images of a sphere free from undersampling artifact. For a prolate spheroidal (head-like) object, 1.75 times and 2.6 times more trajectories were required for 3D Cones. Yarnball produced 0.72 mm (1/2kmax ) isotropic T1 -weighted human brain images free from undersampling artifact in only 98 seconds at 3 T. CONCLUSION Yarnball demonstrated greater k-space sampling efficiency than directly comparable 3D Cones, and may have value wherever 3D Cones has been considered. Yarnball may also have value in the context of rapid T1 -weighted brain imaging.
Collapse
Affiliation(s)
- Robert W Stobbe
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, 1098 Research Transition Facility, University of Alberta, Edmonton, Alberta, Canada
| | - Christian Beaulieu
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, 1098 Research Transition Facility, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
15
|
Aizaz M, Moonen RPM, van der Pol JAJ, Prieto C, Botnar RM, Kooi ME. PET/MRI of atherosclerosis. Cardiovasc Diagn Ther 2020; 10:1120-1139. [PMID: 32968664 DOI: 10.21037/cdt.2020.02.09] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myocardial infarction and stroke are the most prevalent global causes of death. Each year 15 million people worldwide die due to myocardial infarction or stroke. Rupture of a vulnerable atherosclerotic plaque is the main underlying cause of stroke and myocardial infarction. Key features of a vulnerable plaque are inflammation, a large lipid-rich necrotic core (LRNC) with a thin or ruptured overlying fibrous cap, and intraplaque hemorrhage (IPH). Noninvasive imaging of these features could have a role in risk stratification of myocardial infarction and stroke and can potentially be utilized for treatment guidance and monitoring. The recent development of hybrid PET/MRI combining the superior soft tissue contrast of MRI with the opportunity to visualize specific plaque features using various radioactive tracers, paves the way for comprehensive plaque imaging. In this review, the use of hybrid PET/MRI for atherosclerotic plaque imaging in carotid and coronary arteries is discussed. The pros and cons of different hybrid PET/MRI systems are reviewed. The challenges in the development of PET/MRI and potential solutions are described. An overview of PET and MRI acquisition techniques for imaging of atherosclerosis including motion correction is provided, followed by a summary of vessel wall imaging PET/MRI studies in patients with carotid and coronary artery disease. Finally, the future of imaging of atherosclerosis with PET/MRI is discussed.
Collapse
Affiliation(s)
- Mueez Aizaz
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
| | - Rik P M Moonen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
| | - Jochem A J van der Pol
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.,Escuela de Ingenieria, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.,Escuela de Ingenieria, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - M Eline Kooi
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.,CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
| |
Collapse
|
16
|
Munoz C, Bustin A, Neji R, Kunze KP, Forman C, Schmidt M, Hajhosseiny R, Masci PG, Zeilinger M, Wuest W, Botnar RM, Prieto C. Motion-corrected 3D whole-heart water-fat high-resolution late gadolinium enhancement cardiovascular magnetic resonance imaging. J Cardiovasc Magn Reson 2020; 22:53. [PMID: 32684167 PMCID: PMC7370486 DOI: 10.1186/s12968-020-00649-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 06/17/2020] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Conventional 2D inversion recovery (IR) and phase sensitive inversion recovery (PSIR) late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) have been widely incorporated into routine CMR for the assessment of myocardial viability. However, reliable suppression of fat signal, and increased isotropic spatial resolution and volumetric coverage within a clinically feasible scan time remain a challenge. In order to address these challenges, this work proposes a highly efficient respiratory motion-corrected 3D whole-heart water/fat LGE imaging framework. METHODS An accelerated IR-prepared 3D dual-echo acquisition and motion-corrected reconstruction framework for whole-heart water/fat LGE imaging was developed. The acquisition sequence includes 2D image navigators (iNAV), which are used to track the respiratory motion of the heart and enable 100% scan efficiency. Non-rigid motion information estimated from the 2D iNAVs and from the data itself is integrated into a high-dimensional patch-based undersampled reconstruction technique (HD-PROST), to produce high-resolution water/fat 3D LGE images. A cohort of 20 patients with known or suspected cardiovascular disease was scanned with the proposed 3D water/fat LGE approach. 3D water LGE images were compared to conventional breath-held 2D LGE images (2-chamber, 4-chamber and stack of short-axis views) in terms of image quality (1: full diagnostic to 4: non-diagnostic) and presence of LGE findings. RESULTS Image quality was considered diagnostic in 18/20 datasets for both 2D and 3D LGE magnitude images, with comparable image quality scores (2D: 2.05 ± 0.72, 3D: 1.88 ± 0.90, p-value = 0.62) and overall agreement in LGE findings. Acquisition time for isotropic high-resolution (1.3mm3) water/fat LGE images was 8.0 ± 1.4 min (3-fold acceleration, 60-88 slices covering the whole heart), while 2D LGE images were acquired in 5.6 ± 2.2 min (12-18 slices, including pauses between breath-holds) albeit with a lower spatial resolution (1.40-1.75 mm in-plane × 8 mm slice thickness). CONCLUSION A novel framework for motion-corrected whole-heart 3D water/fat LGE imaging has been introduced. The method was validated in patients with known or suspected cardiovascular disease, showing good agreement with conventional breath-held 2D LGE imaging, but offering higher spatial resolution, improved volumetric coverage and good image quality from a free-breathing acquisition with 100% scan efficiency and predictable scan time.
Collapse
Affiliation(s)
- Camila Munoz
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK.
| | - Aurelien Bustin
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
- MR Research Collaborations, Siemens Healthcare, Frimley, UK
| | - Karl P Kunze
- MR Research Collaborations, Siemens Healthcare, Frimley, UK
| | - Christoph Forman
- Cardiovascular MR Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Michaela Schmidt
- Cardiovascular MR Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Reza Hajhosseiny
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Pier-Giorgio Masci
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Martin Zeilinger
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Wolfgang Wuest
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| |
Collapse
|
17
|
Respiratory Motion Prediction Using Fusion-Based Multi-Rate Kalman Filtering and Real-Time Golden-Angle Radial MRI. IEEE Trans Biomed Eng 2020; 67:1727-1738. [DOI: 10.1109/tbme.2019.2944803] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
18
|
Bustin A, Rashid I, Cruz G, Hajhosseiny R, Correia T, Neji R, Rajani R, Ismail TF, Botnar RM, Prieto C. 3D whole-heart isotropic sub-millimeter resolution coronary magnetic resonance angiography with non-rigid motion-compensated PROST. J Cardiovasc Magn Reson 2020; 22:24. [PMID: 32299445 PMCID: PMC7161114 DOI: 10.1186/s12968-020-00611-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 02/19/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND To enable free-breathing whole-heart sub-millimeter resolution coronary magnetic resonance angiography (CMRA) in a clinically feasible scan time by combining low-rank patch-based undersampled reconstruction (3D-PROST) with a highly accelerated non-rigid motion correction framework. METHODS Non-rigid motion corrected CMRA combined with 2D image-based navigators has been previously proposed to enable 100% respiratory scan efficiency in modestly undersampled acquisitions. Achieving sub-millimeter isotropic resolution with such techniques still requires prohibitively long acquisition times. We propose to combine 3D-PROST reconstruction with a highly accelerated non-rigid motion correction framework to achieve sub-millimeter resolution CMRA in less than 10 min. Ten healthy subjects and eight patients with suspected coronary artery disease underwent 4-5-fold accelerated free-breathing whole-heart CMRA with 0.9 mm3 isotropic resolution. Vessel sharpness, vessel length and image quality obtained with the proposed non-rigid (NR) PROST approach were compared against translational correction only (TC-PROST) and a previously proposed NR motion-compensated technique (non-rigid SENSE) in healthy subjects. For the patient study, image quality scoring and visual comparison with coronary computed tomography angiography (CCTA) were performed. RESULTS Average scan times [min:s] were 6:01 ± 0:59 (healthy subjects) and 8:29 ± 1:41 (patients). In healthy subjects, vessel sharpness of the left anterior descending (LAD) and right (RCA) coronary arteries were improved with the proposed non-rigid PROST (LAD: 51.2 ± 8.8%, RCA: 61.2 ± 9.1%) in comparison to TC-PROST (LAD: 43.8 ± 5.1%, P = 0.051, RCA: 54.3 ± 8.3%, P = 0.218) and non-rigid SENSE (LAD: 46.1 ± 5.8%, P = 0.223, RCA: 56.7 ± 9.6%, P = 0.50), although differences were not statistically significant. The average visual image quality score was significantly higher for NR-PROST (LAD: 3.2 ± 0.6, RCA: 3.3 ± 0.7) compared with TC-PROST (LAD: 2.1 ± 0.6, P = 0.018, RCA: 2.0 ± 0.7, P = 0.014) and non-rigid SENSE (LAD: 2.3 ± 0.5, P = 0.008, RCA: 2.5 ± 0.7, P = 0.016). In patients, the proposed approach showed good delineation of the coronaries, in agreement with CCTA, with image quality scores and vessel sharpness similar to that of healthy subjects. CONCLUSIONS We demonstrate the feasibility of combining high undersampling factors with non-rigid motion-compensated reconstruction to obtain high-quality sub-millimeter isotropic CMRA images in ~ 8 min. Validation in a larger cohort of patients with coronary artery disease is now warranted.
Collapse
Affiliation(s)
- Aurélien Bustin
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Imran Rashid
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Gastao Cruz
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Reza Hajhosseiny
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Teresa Correia
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - Radhouene Neji
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
- MR Research Collaborations, Siemens Healthcare Limited, Frimley, UK
| | - Ronak Rajani
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
- Department of Cardiology, Guy's & St Thomas' Hospitals, London, UK
| | - Tevfik F Ismail
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
| | - René M Botnar
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK.
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Claudia Prieto
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
19
|
Malavé MO, Baron CA, Koundinyan SP, Sandino CM, Ong F, Cheng JY, Nishimura DG. Reconstruction of undersampled 3D non-Cartesian image-based navigators for coronary MRA using an unrolled deep learning model. Magn Reson Med 2020; 84:800-812. [PMID: 32011021 DOI: 10.1002/mrm.28177] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 12/04/2019] [Accepted: 12/27/2019] [Indexed: 12/28/2022]
Abstract
PURPOSE To rapidly reconstruct undersampled 3D non-Cartesian image-based navigators (iNAVs) using an unrolled deep learning (DL) model, enabling nonrigid motion correction in coronary magnetic resonance angiography (CMRA). METHODS An end-to-end unrolled network is trained to reconstruct beat-to-beat 3D iNAVs acquired during a CMRA sequence. The unrolled model incorporates a nonuniform FFT operator in TensorFlow to perform the data-consistency operation, and the regularization term is learned by a convolutional neural network (CNN) based on the proximal gradient descent algorithm. The training set includes 6,000 3D iNAVs acquired from 7 different subjects and 11 scans using a variable-density (VD) cones trajectory. For testing, 3D iNAVs from 4 additional subjects are reconstructed using the unrolled model. To validate reconstruction accuracy, global and localized motion estimates from DL model-based 3D iNAVs are compared with those extracted from 3D iNAVs reconstructed with l 1 -ESPIRiT. Then, the high-resolution coronary MRA images motion corrected with autofocusing using the l 1 -ESPIRiT and DL model-based 3D iNAVs are assessed for differences. RESULTS 3D iNAVs reconstructed using the DL model-based approach and conventional l 1 -ESPIRiT generate similar global and localized motion estimates and provide equivalent coronary image quality. Reconstruction with the unrolled network completes in a fraction of the time compared to CPU and GPU implementations of l 1 -ESPIRiT (20× and 3× speed increases, respectively). CONCLUSIONS We have developed a deep neural network architecture to reconstruct undersampled 3D non-Cartesian VD cones iNAVs. Our approach decreases reconstruction time for 3D iNAVs, while preserving the accuracy of nonrigid motion information offered by them for correction.
Collapse
Affiliation(s)
- Mario O Malavé
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA
| | - Corey A Baron
- Department of Medical Biophysics, Western University, London, ON, Canada
| | - Srivathsan P Koundinyan
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA
| | - Christopher M Sandino
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA
| | - Frank Ong
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA
| | - Joseph Y Cheng
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA.,Department of Radiology, Stanford University, Stanford, CA
| | - Dwight G Nishimura
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA
| |
Collapse
|
20
|
Chieh SW, Kaveh M, Akçakaya M, Moeller S. Self-calibrated interpolation of non-Cartesian data with GRAPPA in parallel imaging. Magn Reson Med 2019; 83:1837-1850. [PMID: 31722128 DOI: 10.1002/mrm.28033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/20/2019] [Accepted: 09/17/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE To develop a non-Cartesian k-space reconstruction method using self-calibrated region-specific interpolation kernels for highly accelerated acquisitions. METHODS In conventional non-Cartesian GRAPPA with through-time GRAPPA (TT-GRAPPA), the use of region-specific interpolation kernels has demonstrated improved reconstruction quality in dynamic imaging for highly accelerated acquisitions. However, TT-GRAPPA requires the acquisition of a large number of separate calibration scans. To reduce the overall imaging time, we propose Self-calibrated Interpolation of Non-Cartesian data with GRAPPA (SING) to self-calibrate region-specific interpolation kernels from dynamic undersampled measurements. The SING method synthesizes calibration data to adapt to the distinct shape of each region-specific interpolation kernel geometry, and uses a novel local k-space regularization through an extension of TT-GRAPPA. This calibration approach is used to reconstruct non-Cartesian images at high acceleration rates while mitigating noise amplification. The reconstruction quality of SING is compared with conjugate-gradient SENSE and TT-GRAPPA in numerical phantoms and in vivo cine data sets. RESULTS In both numerical phantom and in vivo cine data sets, SING offers visually and quantitatively similar reconstruction quality to TT-GRAPPA, and provides improved reconstruction quality over conjugate-gradient SENSE. Furthermore, temporal fidelity in SING and TT-GRAPPA is similar for the same acceleration rates. G-factor evaluation over the heart shows that SING and TT-GRAPPA provide similar noise amplification at moderate and high rates. CONCLUSION The proposed SING reconstruction enables significant improvement of acquisition efficiency for calibration data, while matching the reconstruction performance of TT-GRAPPA.
Collapse
Affiliation(s)
- Seng-Wei Chieh
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota
| | - Mostafa Kaveh
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota
| | - Mehmet Akçakaya
- Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota.,Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota
| | - Steen Moeller
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota
| |
Collapse
|
21
|
Zitzelsberger T, Krumm P, Hornung A, Kramer U, Nikolaou K, Schäfer JF, Schick F, Sieverding L, Martirosian P. Multi-phase coronary magnetic resonance angiography improves delineation of coronary arteries. Acta Radiol 2019; 60:1422-1429. [PMID: 30799635 DOI: 10.1177/0284185119830289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Tanja Zitzelsberger
- Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Patrick Krumm
- Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Andreas Hornung
- Department of Pediatric Cardiology, University of Tuebingen, Germany
| | - Ulrich Kramer
- Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Konstantin Nikolaou
- Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Jürgen F Schäfer
- Department of Diagnostic and Interventional Radiology, University of Tuebingen, Germany
| | - Fritz Schick
- Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, University of Tuebingen, Germany
| | - Ludger Sieverding
- Department of Pediatric Cardiology, University of Tuebingen, Germany
| | - Petros Martirosian
- Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, University of Tuebingen, Germany
| |
Collapse
|
22
|
Nordio G, Schneider T, Cruz G, Correia T, Bustin A, Prieto C, Botnar RM, Henningsson M. Whole-heart T 1 mapping using a 2D fat image navigator for respiratory motion compensation. Magn Reson Med 2019; 83:178-187. [PMID: 31400054 PMCID: PMC6791811 DOI: 10.1002/mrm.27919] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 07/01/2019] [Accepted: 07/05/2019] [Indexed: 01/25/2023]
Abstract
Purpose To combine a 3D saturation‐recovery‐based myocardial T1 mapping (3D SASHA) sequence with a 2D image navigator with fat excitation (fat‐iNAV) to allow 3D T1 maps with 100% respiratory scan efficiency and predictable scan time. Methods Data from T1 phantom and 10 subjects were acquired at 1.5T. For respiratory motion compensation, a 2D fat‐iNAV was acquired before each 3D SASHA k‐space segment to correct for 2D translational motion in a beat‐to‐beat fashion. The effect of the fat‐iNAV on the 3D SASHA T1 estimation was evaluated on the T1 phantom. For 3 representative subjects, the proposed free‐breathing 3D SASHA with fat‐iNAV was compared to the original implementation with the diaphragmatic navigator. The 3D SASHA with fat‐iNAV was compared to the breath‐hold 2D SASHA sequence in terms of accuracy and precision. Results In the phantom study, the Bland‐Altman plot shows that the 2D fat‐iNAVs does not affect the T1 quantification of the 3D SASHA acquisition (0 ± 12.5 ms). For the in vivo study, the 2D fat‐iNAV permits to estimate the respiratory motion of the heart, while allowing for 100% scan efficiency, improving the precision of the T1 measurement compared to non‐motion‐corrected 3D SASHA. However, the image quality achieved with the proposed 3D SASHA with fat‐iNAV is lower compared to the original implementation, with reduced delineation of the myocardial borders and papillary muscles. Conclusions We demonstrate the feasibility to combine the 3D SASHA T1 mapping imaging sequence with a 2D fat‐iNAV for respiratory motion compensation, allowing 100% respiratory scan efficiency and predictable scan time.
Collapse
Affiliation(s)
- Giovanna Nordio
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom
| | - Torben Schneider
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom.,Philips Healthcare, Guildford, United Kingdom
| | - Gastao Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom
| | - Teresa Correia
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom
| | - Aurelien Bustin
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Markus Henningsson
- School of Biomedical Engineering and Imaging Sciences, King's College of London, London, United Kingdom
| |
Collapse
|
23
|
Di Sopra L, Piccini D, Coppo S, Stuber M, Yerly J. An automated approach to fully self‐gated free‐running cardiac and respiratory motion‐resolved 5D whole‐heart MRI. Magn Reson Med 2019; 82:2118-2132. [DOI: 10.1002/mrm.27898] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Lorenzo Di Sopra
- Department of Diagnostic and Interventional Radiology Lausanne University Hospital Lausanne Switzerland
| | - Davide Piccini
- Department of Diagnostic and Interventional Radiology Lausanne University Hospital Lausanne Switzerland
- Advanced Clinical Imaging Technology Siemens Healthcare Lausanne Switzerland
| | - Simone Coppo
- Department of Diagnostic and Interventional Radiology Lausanne University Hospital Lausanne Switzerland
| | - Matthias Stuber
- Department of Diagnostic and Interventional Radiology Lausanne University Hospital Lausanne Switzerland
- Center for Biomedical Imaging Lausanne Switzerland
| | - Jérôme Yerly
- Department of Diagnostic and Interventional Radiology Lausanne University Hospital Lausanne Switzerland
- Center for Biomedical Imaging Lausanne Switzerland
| |
Collapse
|
24
|
Zeng DY, Shaikh J, Holmes S, Brunsing RL, Pauly JM, Nishimura DG, Vasanawala SS, Cheng JY. Deep residual network for off-resonance artifact correction with application to pediatric body MRA with 3D cones. Magn Reson Med 2019; 82:1398-1411. [PMID: 31115936 DOI: 10.1002/mrm.27825] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/28/2019] [Accepted: 05/01/2019] [Indexed: 01/06/2023]
Abstract
PURPOSE To enable rapid imaging with a scan time-efficient 3D cones trajectory with a deep-learning off-resonance artifact correction technique. METHODS A residual convolutional neural network to correct off-resonance artifacts (Off-ResNet) was trained with a prospective study of pediatric MRA exams. Each exam acquired a short readout scan (1.18 ms ± 0.38) and a long readout scan (3.35 ms ± 0.74) at 3 T. Short readout scans, with longer scan times but negligible off-resonance blurring, were used as reference images and augmented with additional off-resonance for supervised training examples. Long readout scans, with greater off-resonance artifacts but shorter scan time, were corrected by autofocus and Off-ResNet and compared with short readout scans by normalized RMS error, structural similarity index, and peak SNR. Scans were also compared by scoring on 8 anatomical features by two radiologists, using analysis of variance with post hoc Tukey's test and two one-sided t-tests. Reader agreement was determined with intraclass correlation. RESULTS The total scan time for long readout scans was on average 59.3% shorter than short readout scans. Images from Off-ResNet had superior normalized RMS error, structural similarity index, and peak SNR compared with uncorrected images across ±1 kHz off-resonance (P < .01). The proposed method had superior normalized RMS error over -677 Hz to +1 kHz and superior structural similarity index and peak SNR over ±1 kHz compared with autofocus (P < .01). Radiologic scoring demonstrated that long readout scans corrected with Off-ResNet were noninferior to short readout scans (P < .05). CONCLUSION The proposed method can correct off-resonance artifacts from rapid long-readout 3D cones scans to a noninferior image quality compared with diagnostically standard short readout scans.
Collapse
Affiliation(s)
- David Y Zeng
- Department of Electrical Engineering, Stanford University, Stanford, California
| | - Jamil Shaikh
- Department of Radiology, Stanford University, Stanford, California
| | - Signy Holmes
- Department of Radiology, Stanford University, Stanford, California
| | - Ryan L Brunsing
- Department of Radiology, Stanford University, Stanford, California
| | - John M Pauly
- Department of Electrical Engineering, Stanford University, Stanford, California
| | - Dwight G Nishimura
- Department of Electrical Engineering, Stanford University, Stanford, California
| | | | - Joseph Y Cheng
- Department of Radiology, Stanford University, Stanford, California
| |
Collapse
|
25
|
Velasco Forte MN, Valverde I, Prabhu N, Correia T, Narayan SA, Bell A, Mathur S, Razavi R, Hussain T, Pushparajah K, Henningsson M. Visualization of coronary arteries in paediatric patients using whole-heart coronary magnetic resonance angiography: comparison of image-navigation and the standard approach for respiratory motion compensation. J Cardiovasc Magn Reson 2019; 21:13. [PMID: 30798789 PMCID: PMC6388473 DOI: 10.1186/s12968-019-0525-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 02/05/2019] [Indexed: 11/10/2022] Open
Abstract
AIMS To investigate the use of respiratory motion compensation using image-based navigation (iNAV) with constant respiratory efficiency using single end-expiratory thresholding (CRUISE) for coronary magnetic resonance angiography (CMRA), and compare it to the conventional diaphragmatic navigator (dNAV) in paediatric patients with congenital or suspected heart disease. METHODS iNAV allowed direct tracking of the respiratory heart motion and was generated using balanced steady state free precession startup echoes. Respiratory gating was achieved using CRUISE with a fixed 50% efficiency. Whole-heart CMRA was acquired with 1.3 mm isotropic resolution. For comparison, CMRA with identical imaging parameters were acquired using dNAV. Scan time, visualization of coronary artery origins and mid-course, imaging quality and sharpness was compared between the two sequences. RESULTS Forty patients (13 females; median weight: 44 kg; median age: 12.6, range: 3 months-17 years) were enrolled. 25 scans were performed in awake patients. A contrast agent was used in 22 patients. The scan time was significantly reduced using iNAV for awake patients (iNAV 7:48 ± 1:26 vs dNAV 9:48 ± 3:11, P = 0.01) but not for patients under general anaesthesia (iNAV = 6:55 ± 1:50 versus dNAV = 6:32 ± 2:16; P = 0.32). In 98% of the cases, iNAV image quality had an equal or higher score than dNAV. The visual score analysis showed a clear difference, favouring iNAV (P = 0.002). The right coronary artery and the left anterior descending vessel sharpness was significantly improved (iNAV: 56.8% ± 10.1% vs dNAV: 53.7% ± 9.9%, P < 0.002 and iNAV: 55.8% ± 8.6% vs dNAV: 53% ± 9.2%, P = 0.001, respectively). CONCLUSION iNAV allows for a higher success-rate and clearer depiction of the mid-course of coronary arteries in paediatric patients. Its acquisition time is shorter in awake patients and image quality score is equal or superior to the conventional method in most cases.
Collapse
Affiliation(s)
- Mari Nieves Velasco Forte
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
- Cardiovascular Pathology Unit, Institute of Biomedicine of Seville, IBIS, Virgen del Rocio University Hospital/CSIC/University of Seville, Seville, Spain
| | - Israel Valverde
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
- Cardiovascular Pathology Unit, Institute of Biomedicine of Seville, IBIS, Virgen del Rocio University Hospital/CSIC/University of Seville, Seville, Spain
| | - Nanda Prabhu
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
| | - Teresa Correia
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Srinivas Ananth Narayan
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
| | - Aaron Bell
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
| | - Sujeev Mathur
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
| | - Reza Razavi
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
| | - Tarique Hussain
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Pediatrics, University of Texas Southwestern Medical Center, 1935 Medical District Drive, Dallas, USA
| | - Kuberan Pushparajah
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department of Congenital Heart Disease, Evelina London Children’s Hospital, Guy’s and St Thomas NHS Foundation Trust, London, UK
| | - Markus Henningsson
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| |
Collapse
|
26
|
Malavé MO, Baron CA, Addy NO, Cheng JY, Yang PC, Hu BS, Nishimura DG. Whole-heart coronary MR angiography using a 3D cones phyllotaxis trajectory. Magn Reson Med 2018; 81:1092-1103. [PMID: 30370941 DOI: 10.1002/mrm.27475] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 07/08/2018] [Accepted: 07/10/2018] [Indexed: 01/28/2023]
Abstract
PURPOSE To develop a 3D cones steady-state free precession sequence with improved robustness to respiratory motion while mitigating eddy current artifacts for free-breathing whole-heart coronary magnetic resonance angiography. METHOD The proposed sequence collects cone interleaves using a phyllotaxis pattern, which allows for more distributed k-space sampling for each heartbeat compared to a typical sequential collection pattern. A Fibonacci number of segments is chosen to minimize eddy current effects with the trade-off of an increased number of acquisition heartbeats. For verification, phyllotaxis-cones is compared to sequential-cones through simulations, phantom studies, and in vivo coronary scans with 8 subjects using 2D image-based navigators for retrospective motion correction. RESULTS Simulated point spread functions and moving phantom results show less coherent motion artifacts for phyllotaxis-cones compared to sequential-cones. Assessment of the right and left coronary arteries using reader scores and the image edge profile acutance vessel sharpness metric indicate superior image quality and sharpness for phyllotaxis-cones. CONCLUSION Phyllotaxis 3D cones results in improved qualitative image scores and coronary vessel sharpness for free-breathing whole-heart coronary magnetic resonance angiography compared to standard sequential ordering when using a steady-state free precession sequence.
Collapse
Affiliation(s)
- Mario O Malavé
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California
| | - Corey A Baron
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California
| | - Nii Okai Addy
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California
| | - Joseph Y Cheng
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California.,Department of Radiology, Stanford University, Palo Alto, California
| | - Phillip C Yang
- Cardiovascular Medicine, Stanford University, Stanford, California
| | - Bob S Hu
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California.,Cardiology, Palo Alto Medical Foundation, Palo Alto, California
| | - Dwight G Nishimura
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California
| |
Collapse
|
27
|
Moyé DM, Hussain T, Botnar RM, Tandon A, Greil GF, Dyer AK, Henningsson M. Dual-phase whole-heart imaging using image navigation in congenital heart disease. BMC Med Imaging 2018; 18:36. [PMID: 30326847 PMCID: PMC6192322 DOI: 10.1186/s12880-018-0278-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/01/2018] [Indexed: 02/04/2023] Open
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.
Collapse
Affiliation(s)
- Danielle M Moyé
- Department of Pediatrics, Division of Cardiology, UT Southwestern Medical Center Dallas, Dallas, TX, USA. .,Department of Pediatrics, Division of Cardiology, Children's Health, Children's Medical Center Dallas, Dallas, TX, USA. .,Pediatric Cardiology, Children's Health Children's Medical Center of Dallas, 1935 Medical District Drive, Dallas, TX, 75235, USA.
| | - Tarique Hussain
- Department of Pediatrics, Division of Cardiology, UT Southwestern Medical Center Dallas, Dallas, TX, USA.,Department of Pediatrics, Division of Cardiology, Children's Health, Children's Medical Center Dallas, Dallas, TX, USA.,Departments of Radiology and Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rene M Botnar
- Division of Imaging Sciences, King's College London, London, UK.,Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile
| | - Animesh Tandon
- Department of Pediatrics, Division of Cardiology, UT Southwestern Medical Center Dallas, Dallas, TX, USA.,Department of Pediatrics, Division of Cardiology, Children's Health, Children's Medical Center Dallas, Dallas, TX, USA.,Departments of Radiology and Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gerald F Greil
- Department of Pediatrics, Division of Cardiology, UT Southwestern Medical Center Dallas, Dallas, TX, USA.,Department of Pediatrics, Division of Cardiology, Children's Health, Children's Medical Center Dallas, Dallas, TX, USA.,Departments of Radiology and Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Adrian K Dyer
- Department of Pediatrics, Division of Cardiology, UT Southwestern Medical Center Dallas, Dallas, TX, USA.,Department of Pediatrics, Division of Cardiology, Children's Health, Children's Medical Center Dallas, Dallas, TX, USA
| | | |
Collapse
|
28
|
Bustin A, Ginami G, Cruz G, Correia T, Ismail TF, Rashid I, Neji R, Botnar RM, Prieto C. Five-minute whole-heart coronary MRA with sub-millimeter isotropic resolution, 100% respiratory scan efficiency, and 3D-PROST reconstruction. Magn Reson Med 2018; 81:102-115. [PMID: 30058252 PMCID: PMC6617822 DOI: 10.1002/mrm.27354] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/23/2018] [Accepted: 04/19/2018] [Indexed: 01/08/2023]
Abstract
Purpose To enable whole‐heart 3D coronary magnetic resonance angiography (CMRA) with isotropic sub‐millimeter resolution in a clinically feasible scan time by combining respiratory motion correction with highly accelerated variable density sampling in concert with a novel 3D patch‐based undersampled reconstruction (3D‐PROST). Methods An undersampled variable density spiral‐like Cartesian trajectory was combined with 2D image‐based navigators to achieve 100% respiratory efficiency and predictable scan time. 3D‐PROST reconstruction integrates structural information from 3D patch neighborhoods through sparse representation, thereby exploiting the redundancy of the 3D anatomy of the coronary arteries in an efficient low‐rank formulation. The proposed framework was evaluated in a static resolution phantom and in 10 healthy subjects with isotropic resolutions of 1.2 mm3 and 0.9 mm3 and undersampling factors of ×5 and ×9. 3D‐PROST was compared against fully sampled (1.2 mm3 only), conventional parallel imaging, and compressed sensing reconstructions. Results Phantom and in vivo (1.2 mm3) reconstructions were in excellent agreement with the reference fully sampled image. In vivo average acquisition times (min:s) were 7:57 ± 1:18 (×5) and 4:35 ± 0:44 (×9) for 0.9 mm3 resolution. Sub‐millimeter 3D‐PROST resulted in excellent depiction of the left and right coronary arteries including small branch vessels, leading to further improvements in vessel sharpness and visible vessel length in comparison with conventional reconstruction techniques. Image quality rated by 2 experts demonstrated that 3D‐PROST provides good image quality and is robust even at high acceleration factors. Conclusion The proposed approach enables free‐breathing whole‐heart 3D CMRA with isotropic sub‐millimeter resolution in <5 min and achieves improved coronary artery visualization in a short and predictable scan time.
Collapse
Affiliation(s)
- Aurélien Bustin
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Giulia Ginami
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Gastão Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Teresa Correia
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Tevfik F Ismail
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Imran Rashid
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
29
|
Correia T, Ginami G, Cruz G, Neji R, Rashid I, Botnar RM, Prieto C. Optimized respiratory-resolved motion-compensated 3D Cartesian coronary MR angiography. Magn Reson Med 2018; 80:2618-2629. [PMID: 29682783 PMCID: PMC6220806 DOI: 10.1002/mrm.27208] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 11/29/2022]
Abstract
Purpose To develop a robust and efficient reconstruction framework that provides high‐quality motion‐compensated respiratory‐resolved images from free‐breathing 3D whole‐heart Cartesian coronary magnetic resonance angiography (CMRA) acquisitions. Methods Recently, XD‐GRASP (eXtra‐Dimensional Golden‐angle RAdial Sparse Parallel MRI) was proposed to achieve 100% scan efficiency and provide respiratory‐resolved 3D radial CMRA images by exploiting sparsity in the respiratory dimension. Here, a reconstruction framework for Cartesian CMRA imaging is proposed, which provides respiratory‐resolved motion‐compensated images by incorporating 2D beat‐to‐beat translational motion information to increase sparsity in the respiratory dimension. The motion information is extracted from interleaved image navigators and is also used to compensate for 2D translational motion within each respiratory phase. The proposed Optimized Respiratory‐resolved Cartesian Coronary MR Angiography (XD‐ORCCA) method was tested on 10 healthy subjects and 2 patients with cardiovascular disease, and compared against XD‐GRASP. Results The proposed XD‐ORCCA provides high‐quality respiratory‐resolved images, allowing clear visualization of the right and left coronary arteries, even for irregular breathing patterns. Compared with XD‐GRASP, the proposed method improves the visibility and sharpness of both coronaries. Significant differences (p < .05) in visible vessel length and proximal vessel sharpness were found between the 2 methods. The XD‐GRASP method provides good‐quality images in the absence of intraphase motion. However, motion blurring is observed in XD‐GRASP images for respiratory phases with larger motion amplitudes and subjects with irregular breathing patterns. Conclusion A robust respiratory‐resolved motion‐compensated framework for Cartesian CMRA has been proposed and tested in healthy subjects and patients. The proposed XD‐ORCCA provides high‐quality images for all respiratory phases, independently of the regularity of the breathing pattern.
Collapse
Affiliation(s)
- Teresa Correia
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Giulia Ginami
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Gastão Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - Imran Rashid
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
30
|
Silva Vieira M, Henningsson M, Dedieu N, Vassiliou VS, Bell A, Mathur S, Pushparajah K, Figueroa CA, Hussain T, Botnar R, Greil GF. Improved coronary magnetic resonance angiography using gadobenate dimeglumine in pediatric congenital heart disease. Magn Reson Imaging 2018; 49:47-54. [PMID: 29339139 DOI: 10.1016/j.mri.2017.12.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 12/25/2017] [Accepted: 12/29/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND CMRA in pediatrics remains challenging due to the smaller vessel size, high heart rates (HR), potential image degradation caused by limited patient cooperation and long acquisition times. High-relaxivity contrast agents have been shown to improve coronary imaging in adults, but limited data is available in children. We sought to investigate whether gadobenate dimeglumine (Gd-BOPTA) together with self-navigated inversion-prepared coronary magnetic resonance angiography (CMRA) sequence design improves coronary image quality in pediatric patients. METHODS Forty consecutive patients (mean age 6±2.8years; 73% males) were prospectively recruited for a 1.5-T MRI study under general anesthesia. Two electrocardiographic-triggered free breathing steady-state free precession (SSFP) angiography sequences (A and B) with isotropic spatial resolution (1.3mm3) were acquired using a recently developed image-based self-navigation technique. Sequence A was acquired prior to contrast administration using T2 magnetization preparation (T2prep). Sequence B was acquired 5-8min after a bolus of Gd-BOPTA with the T2prep replaced by an inversion recovery (IR) pulse to null the signal from the myocardium. Scan time, signal-to noise and contrast-to-noise ratios (SNR and CNR), vessel wall sharpness (VWS) and qualitative visual score for each sequence were compared. RESULTS Scan time was similar for both sequences (5.3±1.8 vs 5.2±1.5min, p=.532) and average heart rate (78±14.7 vs 78±14.5bpm, p=.443) remained constant throughout both acquisitions. Sequence B resulted in higher SNR (12.6±4.4 vs 31.1±7.4, p<.001) and CNR (9.0±1.8 vs 13.5±3.7, p<.001) and provided improved coronary visualization in all coronary territories (VWS A=0.53±0.07 vs B=0.56±0.07, p=.001; and visual scoring A=3.8±0.59 vs B=4.1±0.53, p<.001). The number of non-diagnostic coronary segments was lower for sequence B [A=42 (13.1%) segments vs B=33 (10.3%) segments; p=.002], and contrary to the pre-contrast sequence, never involved a proximal segment. These results were independent of the patients' age, body surface area and HR. CONCLUSIONS The use of Gd-BOPTA with a 3D IR SSFP CMRA sequence results in improved coronary visualization in small infants and young children with high HR within a clinically acceptable scan time.
Collapse
Affiliation(s)
- Miguel Silva Vieira
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK.
| | - Markus Henningsson
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK.
| | - Nathalie Dedieu
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
| | | | - Aaron Bell
- Evelina Children's Hospital London, Guy's and St. Thomas' NHS Foundation Trust, London, UK.
| | - Sujeev Mathur
- Evelina Children's Hospital London, Guy's and St. Thomas' NHS Foundation Trust, London, UK.
| | - Kuberan Pushparajah
- Evelina Children's Hospital London, Guy's and St. Thomas' NHS Foundation Trust, London, UK.
| | - Carlos Alberto Figueroa
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK; Departments of Surgery and Biomedical Engineering, University of Michigan, MI, USA.
| | - Tarique Hussain
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA.
| | - René Botnar
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK; Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile.
| | - Gerald F Greil
- Division of Imaging Sciences & Biomedical Engineering, King's College London, London, UK; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, USA.
| |
Collapse
|
31
|
Correia T, Cruz G, Schneider T, Botnar RM, Prieto C. Technical note: Accelerated nonrigid motion-compensated isotropic 3D coronary MR angiography. Med Phys 2017; 45:214-222. [PMID: 29131353 PMCID: PMC5814733 DOI: 10.1002/mp.12663] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/09/2017] [Accepted: 11/01/2017] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To develop an accelerated and nonrigid motion-compensated technique for efficient isotropic 3D whole-heart coronary magnetic resonance angiography (CMRA) with Cartesian acquisition. METHODS Highly efficient whole-heart 3D CMRA was achieved by combining image reconstruction from undersampled data using compressed sensing (CS) with a nonrigid motion compensation framework. Undersampled acquisition was performed using a variable-density Cartesian trajectory with radial order (VD-CAPR). Motion correction was performed in two steps: beat-to-beat 2D translational correction with motion estimated from interleaved image navigators, and bin-to-bin 3D nonrigid correction with motion estimated from respiratory-resolved images reconstructed from undersampled 3D CMRA data using CS. Nonrigid motion fields were incorporated into an undersampled motion-compensated reconstruction, which combines CS with the general matrix description formalism. The proposed approach was tested on 10 healthy subjects and compared against a conventional twofold accelerated 5-mm navigator-gated and tracked acquisition. RESULTS The proposed method achieves isotropic 1.2-mm Cartesian whole-heart CMRA in 5 min ± 1 min (~8× acceleration). The proposed approach provides good-quality images of the left and right coronary arteries, comparable to those of a twofold accelerated navigator-gated and tracked acquisition, but scan time was up to about four times faster. For both coronaries, no significant differences (P > 0.05) in vessel sharpness and length were found between the proposed method and reference scan. CONCLUSION The feasibility of a highly efficient motion-compensated reconstruction framework for accelerated 3D CMRA has been demonstrated in healthy subjects. Further investigation is required to assess the clinical value of the method.
Collapse
Affiliation(s)
- Teresa Correia
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | - Gastão Cruz
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK
| | | | - René M Botnar
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.,Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile
| | - Claudia Prieto
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.,Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile
| |
Collapse
|
32
|
Baron CA, Dwork N, Pauly JM, Nishimura DG. Rapid compressed sensing reconstruction of 3D non-Cartesian MRI. Magn Reson Med 2017; 79:2685-2692. [PMID: 28940748 DOI: 10.1002/mrm.26928] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 11/10/2022]
Abstract
PURPOSE Conventional non-Cartesian compressed sensing requires multiple nonuniform Fourier transforms every iteration, which is computationally expensive. Accordingly, time-consuming reconstructions have slowed the adoption of undersampled 3D non-Cartesian acquisitions into clinical protocols. In this work we investigate several approaches to minimize reconstruction times without sacrificing accuracy. METHODS The reconstruction problem can be reformatted to exploit the Toeplitz structure of matrices that are evaluated every iteration, but it requires larger oversampling than what is strictly required by nonuniform Fourier transforms. Accordingly, we investigate relative speeds of the two approaches for various nonuniform Fourier transform kernel sizes and oversampling for both GPU and CPU implementations. Second, we introduce a method to minimize matrix sizes by estimating the image support. Finally, density compensation weights have been used as a preconditioning matrix to improve convergence, but this increases noise. We propose a more general approach to preconditioning that allows a trade-off between accuracy and convergence speed. RESULTS When using a GPU, the Toeplitz approach was faster for all practical parameters. Second, it was found that properly accounting for image support can prevent aliasing errors with minimal impact on reconstruction time. Third, the proposed preconditioning scheme improved convergence rates by an order of magnitude with negligible impact on noise. CONCLUSION With the proposed methods, 3D non-Cartesian compressed sensing with clinically relevant reconstruction times (<2 min) is feasible using practical computer resources. Magn Reson Med 79:2685-2692, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Corey A Baron
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Nicholas Dwork
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - John M Pauly
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Dwight G Nishimura
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| |
Collapse
|
33
|
Henningsson M, Shome J, Bratis K, Vieira MS, Nagel E, Botnar RM. Diagnostic performance of image navigated coronary CMR angiography in patients with coronary artery disease. J Cardiovasc Magn Reson 2017; 19:68. [PMID: 28893296 PMCID: PMC5594598 DOI: 10.1186/s12968-017-0381-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/17/2017] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The use of coronary MR angiography (CMRA) in patients with coronary artery disease (CAD) remains limited due to the long scan times, unpredictable and often non-diagnostic image quality secondary to respiratory motion artifacts. The purpose of this study was to evaluate CMRA with image-based respiratory navigation (iNAV CMRA) and compare it to gold standard invasive x-ray coronary angiography in patients with CAD. METHODS Consecutive patients referred for CMR assessment were included to undergo iNAV CMRA on a 1.5 T scanner. Coronary vessel sharpness and a visual score were assigned to the coronary arteries. A diagnostic reading was performed on the iNAV CMRA data, where a lumen narrowing >50% was considered diseased. This was compared to invasive x-ray findings. RESULTS Image-navigated CMRA was performed in 31 patients (77% male, 56 ± 14 years). The iNAV CMRA scan time was 7 min:21 s ± 0 min:28 s. Out of a possible 279 coronary segments, 26 segments were excluded from analysis due to stents or diameter less than 1.5 mm, resulting in a total of 253 coronary segments. Diagnostic image quality was obtained for 98% of proximal coronary segments, 94% of middle segments, and 91% of distal coronary segments. The sensitivity and specificity was 86% and 83% per patient, 80% and 92% per vessel and 73% and 95% per segment. CONCLUSION In this study, iNAV CMRA offered a very good diagnostic performance when compared against invasive x-ray angiography. Due to the short and predictable scan time it can add clinical value as a part of a comprehensive CAD assessment protocol.
Collapse
Affiliation(s)
- Markus Henningsson
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Joy Shome
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Konstantinos Bratis
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Miguel Silva Vieira
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Eike Nagel
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Institute for Experimental and Translational Cardiovascular Imaging, Goethe University, Frankfurt/Main, Germany
- DZHK (German Centre for Cardiovascular Research, Standort RheinMain), Berlin, Germany
| | - Rene M. Botnar
- Division of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| |
Collapse
|
34
|
Feng L, Coppo S, Piccini D, Yerly J, Lim RP, Masci PG, Stuber M, Sodickson DK, Otazo R. 5D whole-heart sparse MRI. Magn Reson Med 2017; 79:826-838. [PMID: 28497486 DOI: 10.1002/mrm.26745] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 04/09/2017] [Accepted: 04/11/2017] [Indexed: 01/18/2023]
Abstract
PURPOSE A 5D whole-heart sparse imaging framework is proposed for simultaneous assessment of myocardial function and high-resolution cardiac and respiratory motion-resolved whole-heart anatomy in a single continuous noncontrast MR scan. METHODS A non-electrocardiograph (ECG)-triggered 3D golden-angle radial balanced steady-state free precession sequence was used for data acquisition. The acquired 3D k-space data were sorted into a 5D dataset containing separated cardiac and respiratory dimensions using a self-extracted respiratory motion signal and a recorded ECG signal. Images were then reconstructed using XD-GRASP, a multidimensional compressed sensing technique exploiting correlations/sparsity along cardiac and respiratory dimensions. 5D whole-heart imaging was compared with respiratory motion-corrected 3D and 4D whole-heart imaging in nine volunteers for evaluation of the myocardium, great vessels, and coronary arteries. It was also compared with breath-held, ECG-gated 2D cardiac cine imaging for validation of cardiac function quantification. RESULTS 5D whole-heart images received systematic higher quality scores in the myocardium, great vessels and coronary arteries. Quantitative coronary sharpness and length were always better for the 5D images. Good agreement was obtained for quantification of cardiac function compared with 2D cine imaging. CONCLUSION 5D whole-heart sparse imaging represents a robust and promising framework for simplified comprehensive cardiac MRI without the need for breath-hold and motion correction. Magn Reson Med 79:826-838, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Li Feng
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Simone Coppo
- Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Center for Biomedical Imaging (CIBM), Lausanne, Switzerland
| | - Davide Piccini
- Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland
| | - Jerome Yerly
- Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Center for Biomedical Imaging (CIBM), Lausanne, Switzerland
| | - Ruth P Lim
- Department of Radiology, Austin Health and The University of Melbourne, Melbourne, Victoria, Australia
| | - Pier Giorgio Masci
- Division of Cardiology and Cardiac MR Center, University Hospital (CHUV), Lausanne, Switzerland
| | - Matthias Stuber
- Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Center for Biomedical Imaging (CIBM), Lausanne, Switzerland
| | - Daniel K Sodickson
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Ricardo Otazo
- Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| |
Collapse
|
35
|
Henningsson M, Smink J, van Ensbergen G, Botnar R. Coronary MR angiography using image-based respiratory motion compensation with inline correction and fixed gating efficiency. Magn Reson Med 2017; 79:416-422. [PMID: 28321900 PMCID: PMC5763408 DOI: 10.1002/mrm.26678] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/13/2017] [Accepted: 02/22/2017] [Indexed: 12/26/2022]
Abstract
PURPOSE The purpose of this study was to evaluate a new inline motion compensation approach called image-based navigation with Constant Respiratory efficiency UsIng Single End-expiratory threshold (iNAV-CRUISE) for coronary MR angiography (CMRA). METHODS The CRUISE gating technique was combined with iNAV motion correction and implemented inline for motion-compensated CMRA on a 1.5 Tesla scanner. The approach was compared to conventional diaphragmatic navigator gating (dNAVG) in 10 healthy subjects. The CMRA images were compared for vessel sharpness and visual score of the right coronary artery (RCA), left anterior descending artery (LAD), left circumflex, and scan time. RESULTS The scan time was similar between the methods (dNAVG : 6:32 ± 1:09 vs. iNAV-CRUISE: 6:58 ± 0:17, P = not significant). However, the vessel sharpness of the RCA (dNAVG : 60.2 ± 10.1 vs. iNAV-CRUISE: 71.8 ± 8.9, P = 0.001) and LAD (dNAVG : 58.0 ± 8.0 vs. iNAV-CRUISE: 67.4 ± 7.1, P = 0.008) were significantly improved using iNAV-CRUISE. The visual score of the RCA was higher using iNAV-CRUISE compared to dNAVG (dNAVG : 3,4,3 vs. iNAV-CRUISE: 4,4,3, P < 0.01). CONCLUSION The iNAV-CRUISE approach out-performs the conventional respiratory motion compensation technique in healthy subjects. Although scan time was comparable, the image quality was improved using iNAV-CRUISE. Magn Reson Med 79:416-422, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Collapse
Affiliation(s)
- Markus Henningsson
- Division of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | | | | | - Rene Botnar
- Division of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| |
Collapse
|
36
|
Baron CA, Nishimura DG. B 0 mapping using rewinding trajectories (BMART). Magn Reson Med 2016; 78:664-669. [PMID: 27555219 DOI: 10.1002/mrm.26391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/27/2016] [Accepted: 07/27/2016] [Indexed: 11/10/2022]
Abstract
PURPOSE To create a B0 map and correct for off-resonance with minimal scan time increase for two-dimensional (2D) or 3D non-Cartesian acquisitions. METHODS Rewinding trajectories that bring the zeroth gradient moment to zero every repetition time (TR) were used to estimate the off-resonance with a center-out 3D cones trajectory, which required an increase in the minimum TR by 5%. The off-resonance estimation and correction was implemented using an algorithm based on binning and object-domain phase correction. B0 maps using BMART (B0 mapping using rewinding trajectories) were compared to maps obtained using separate scans with multiple echo time (TE) in a phantom and human brain. RESULTS Excellent agreement between BMART and the multiple-TE method were observed, and images corrected with BMART were deblurred. CONCLUSION BMART can correct for off-resonance without requiring an additional scan, and can be easily applied to center-out or projection trajectories (2D or 3D). Magn Reson Med 78:664-669, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Corey A Baron
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Dwight G Nishimura
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| |
Collapse
|
37
|
Pang J, Chen Y, Fan Z, Nguyen C, Yang Q, Xie Y, Li D. High efficiency coronary MR angiography with nonrigid cardiac motion correction. Magn Reson Med 2016; 76:1345-1353. [PMID: 27455164 DOI: 10.1002/mrm.26332] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 06/09/2016] [Accepted: 06/15/2016] [Indexed: 11/05/2022]
Abstract
PURPOSE To improve the coronary visualization quality of four-dimensional (4D) coronary MR angiography (MRA) through cardiac motion correction and iterative reconstruction. METHODS A contrast-enhanced, spoiled gradient echo sequence with 3D radial trajectory and self-gating was used for 4D coronary MRA data acquisition at 3 Tesla. A whole-heart 16-phase cine series was reconstructed with respiratory motion correction. Nonrigid registration was performed between the identified quiescent phases and a reference. The motion information of all included phases was then used along with the corresponding k-space data to iteratively reconstruct the final image. Healthy volunteer studies (N = 13) were conducted to compare the proposed method with the conventional strategy, which accepts data from a single, contiguous window out of the original 16-phase data. Apparent signal-to-noise ratio (aSNR) and coronary sharpness were used as the image quality metrics. RESULTS The proposed method significantly improved aSNR (11.89 ± 3.76 to 13.97 ± 5.21; P = 0.005) and scan efficiency (18.8% ± 6.0% to 40.9% ± 9.7%; P < 0.001), compared with the conventional strategy. Sharpness of left main (P = 0.002), proximal (P = 0.04), and middle (P = 0.02) right coronary artery, and proximal left anterior descending (P = 0.04) was also significantly improved. CONCLUSION The proposed cardiac motion-corrected reconstruction significantly improved the achievable quality of coronary visualization from 4D coronary MRA. Magn Reson Med 76:1345-1353, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Jianing Pang
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Yuhua Chen
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Computer and Information Science, University of Pennsylvania, Philadelphia, Pennyslvania, USA
| | - Zhaoyang Fan
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Christopher Nguyen
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Qi Yang
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Yibin Xie
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Debiao Li
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA. .,Bioengineering, University of California, Los Angeles, California, USA.
| |
Collapse
|
38
|
Luo J, Addy NO, Ingle RR, Baron CA, Cheng JY, Hu BS, Nishimura DG. Nonrigid Motion Correction With 3D Image-Based Navigators for Coronary MR Angiography. Magn Reson Med 2016; 77:1884-1893. [PMID: 27174673 DOI: 10.1002/mrm.26273] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 03/31/2016] [Accepted: 04/19/2016] [Indexed: 11/09/2022]
Abstract
PURPOSE To develop a retrospective nonrigid motion-correction method based on 3D image-based navigators (iNAVs) for free-breathing whole-heart coronary magnetic resonance angiography (MRA). METHODS The proposed method detects global rigid-body motion and localized nonrigid motion from 3D iNAVs and compensates them with an autofocusing algorithm. To model the global motion, 3D rotation and translation are estimated from the 3D iNAVs. Two sets of localized nonrigid motions are obtained from deformation fields between 3D iNAVs and reconstructed binned images, respectively. A bank of motion-corrected images is generated and the final image is assembled pixel-by-pixel by selecting the best focused pixel from this bank. In vivo studies with six healthy volunteers were conducted to compare the performance of the proposed method with 3D translational motion correction and no correction. RESULTS In vivo studies showed that compared to no correction, 3D translational motion correction and the proposed method increased the vessel sharpness by 13% ± 13% and 19% ± 16%, respectively. Out of 90 vessel segments, 75 segments showed improvement with the proposed method compared to 3D translational correction. CONCLUSION We have developed a nonrigid motion-correction method based on 3D iNAVs and an autofocusing algorithm that improves the vessel sharpness of free-breathing whole-heart coronary MRA. Magn Reson Med 77:1884-1893, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Jieying Luo
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Nii Okai Addy
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - R Reeve Ingle
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Corey A Baron
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Joseph Y Cheng
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Bob S Hu
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA.,Palo Alto Medical Foundation, Palo Alto, California, USA
| | - Dwight G Nishimura
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| |
Collapse
|
39
|
Addy NO, Ingle RR, Luo J, Baron CA, Yang PC, Hu BS, Nishimura DG. 3D image-based navigators for coronary MR angiography. Magn Reson Med 2016; 77:1874-1883. [PMID: 27174590 DOI: 10.1002/mrm.26269] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 04/13/2016] [Accepted: 04/17/2016] [Indexed: 01/22/2023]
Abstract
PURPOSE To develop a method for acquiring whole-heart 3D image-based navigators (iNAVs) with isotropic resolution for tracking and correction of localized motion in coronary magnetic resonance angiography (CMRA). METHODS To monitor motion in all regions of the heart during a free-breathing scan, a variable-density cones trajectory was designed to collect a 3D iNAV every heartbeat in 176 ms with 4.4 mm isotropic spatial resolution. The undersampled 3D iNAV data were reconstructed with efficient self-consistent parallel imaging reconstruction (ESPIRiT). 3D translational and nonrigid motion-correction methods using 3D iNAVs were compared to previous translational and nonrigid methods using 2D iNAVs. RESULTS Five subjects were scanned with a 3D cones CMRA sequence, accompanied by both 2D and 3D iNAVs. The quality of the right and left anterior descending coronary arteries was assessed on 2D and 3D iNAV-based motion-corrected images using a vessel sharpness metric and qualitative reader scoring. This assessment showed that nonrigid motion correction based on 3D iNAVs produced results that were noninferior to correction based on 2D iNAVs. CONCLUSION The ability to acquire isotropic-resolution 3D iNAVs every heartbeat during a CMRA scan was demonstrated. Such iNAVs enabled direct measurement of localized motion for nonrigid motion correction in free-breathing whole-heart CMRA. Magn Reson Med 77:1874-1883, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Nii Okai Addy
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - R Reeve Ingle
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Jieying Luo
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Corey A Baron
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Phillip C Yang
- Cardiovascular Medicine, Stanford University Medical Center, Stanford, California, USA
| | - Bob S Hu
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA.,Department of Cardiology, Palo Alto Medical Foundation, Palo Alto, California, USA
| | - Dwight G Nishimura
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| |
Collapse
|
40
|
Castets CR, Lefrançois W, Wecker D, Ribot EJ, Trotier AJ, Thiaudière E, Franconi JM, Miraux S. Fast 3D ultrashort echo-time spiral projection imaging using golden-angle: A flexible protocol for in vivo mouse imaging at high magnetic field. Magn Reson Med 2016; 77:1831-1840. [PMID: 27170060 DOI: 10.1002/mrm.26263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 12/21/2022]
Abstract
PURPOSE To develop a fast three-dimensional (3D) k-space encoding method based on spiral projection imaging (SPI) with an interleaved golden-angle approach and to validate this novel sequence on small animal models. METHODS A disk-like trajectory, in which each disk contained spirals, was developed. The 3D encoding was performed by tilting the disks with a golden angle. The sharpness was first calculated at different T2* values. Then, the sharpness was measured on phantom using variable undersampling ratios. Finally, the sampling method was validated by whole brain time-of-flight angiography and ultrasmall superparamagnetic iron oxide (USPIO) enhanced free-breathing liver angiography on mouse. RESULTS The in vitro results demonstrated the robustness of the method for short T2* and high undersampling ratios. In vivo experiments showed the ability to properly detect small vessels in the brain with an acquisition time shorter than 1 min. Free-breathing mice liver angiography showed the insensitivity of this protocol toward motions and flow artifacts, and enabled the visualization of liver motion during breathing. CONCLUSIONS The method implemented here allowed fast 3D k-space sampling with a high undersampling ratio. Combining the advantages of center-out spirals with the flexibility of the golden angle approach could have major implications for real-time imaging. Magn Reson Med 77:1831-1840, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Charles R Castets
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - William Lefrançois
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | | | - Emeline J Ribot
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Aurélien J Trotier
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Eric Thiaudière
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Jean-Michel Franconi
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Sylvain Miraux
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| |
Collapse
|
41
|
Kawaji K, Spincemaille P, Nguyen TD, Thimmappa N, Cooper MA, Prince MR, Wang Y. Direct coronary motion extraction from a 2D fat image navigator for prospectively gated coronary MR angiography. Magn Reson Med 2016; 71:599-607. [PMID: 23504975 DOI: 10.1002/mrm.24698] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE Direct 2D tracking of cardiac motion may provide superior respiratory navigator gating for coronary magnetic resonance angiography compared to conventional liver-diaphragm navigators. However, additional 2D processing for motion extraction is unsuitable for real-time prospective gating. In this work, a 2D fat-selective image navigator, which delineates the epicardial fat surrounding coronary arteries, is developed to directly monitor epicardial fat motion at every heartbeat in real-time for prospective gating. METHODS The proposed navigator is incorporated into a real-time interactive software that allows rapid setup and efficient motion extraction, and runs on standard clinical hardware without any additional dedicated components for processing. The proposed 2D cardiac fat image navigator was compared with the conventional 1D diaphragm navigator in free-breathing b-SSFP coronary MRAs in 12 healthy volunteers at 1.5T. RESULTS Real-time motion extraction from 2D cardiac fat navigator images was feasible within 20 ms, enabling successful prospectively gated coronary magnetic resonance angiographies in all subjects. Compared to 1D diaphragmatic navigator, 2D fat image navigator reduced scan time by 38% (P < 0.0005), and significantly improved vessel sharpness, myocardial suppression, and image quality (P < 0.05). CONCLUSION This demonstrates the feasibility of a 3D SSFP coronary magnetic resonance angiography sequence using a 2D epicardial fat image as a navigator for real-time prospective motion tracking.
Collapse
Affiliation(s)
- Keigo Kawaji
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, USA; Department of Radiology, Weill Cornell Medical College, New York, New York, USA
| | | | | | | | | | | | | |
Collapse
|
42
|
Amsallem M, Saito T, Tada Y, Dash R, McConnell MV. Magnetic Resonance Imaging and Positron Emission Tomography Approaches to Imaging Vascular and Cardiac Inflammation. Circ J 2016; 80:1269-77. [DOI: 10.1253/circj.cj-16-0224] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Myriam Amsallem
- Division of Cardiovascular Medicine, Stanford University School of Medicine
| | - Toshinobu Saito
- Division of Cardiovascular Medicine, Stanford University School of Medicine
| | - Yuko Tada
- Division of Cardiovascular Medicine, Stanford University School of Medicine
| | - Rajesh Dash
- Division of Cardiovascular Medicine, Stanford University School of Medicine
| | | |
Collapse
|
43
|
Luo J, Addy NO, Ingle RR, Hargreaves BA, Hu BS, Nishimura DG, Shin T. Combined outer volume suppression and T2 preparation sequence for coronary angiography. Magn Reson Med 2015; 74:1632-9. [PMID: 25521477 PMCID: PMC4470881 DOI: 10.1002/mrm.25575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 11/10/2014] [Accepted: 11/14/2014] [Indexed: 12/25/2022]
Abstract
PURPOSE To develop a magnetization preparation sequence for simultaneous outer volume suppression (OVS) and T2 weighting in whole-heart coronary magnetic resonance angiography. METHODS A combined OVS and T2 preparation sequence (OVS-T2 Prep) was designed with a nonselective adiabatic 90° tipdown pulse, two adiabatic 180° refocusing pulses, and a 2D spiral -90° tipup pulse. The OVS-T2 Prep preserves the magnetization inside an elliptic cylinder with T2 weighting, while saturating the magnetization outside the cylinder. Its performance was tested on phantoms and on 13 normal subjects with coronary magnetic resonance angiography using 3D cones trajectories. RESULTS Phantom studies showed expected T2 -dependent signal amplitude in the spatial passband and suppressed signal in the spatial stopband. In vivo studies with full-field-of-view cones yielded a passband-to-stopband signal ratio of 3.18 ± 0.77 and blood-myocardium contrast-to-noise ratio enhancement by a factor of 1.43 ± 0.20 (P < 0.001). In vivo studies with reduced-field-of-view cones showed that OVS-T2 Prep well suppressed the aliasing artifacts, as supported by significantly reduced signal in the regions with no tissues compared to the images acquired without preparation (P < 0.0001). CONCLUSION OVS-T2 Prep is a compact sequence that can accelerate coronary magnetic resonance angiography by suppressing signals from tissues surrounding the heart while simultaneously enhancing the blood-myocardium contrast.
Collapse
Affiliation(s)
- Jieying Luo
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Nii Okai Addy
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - R. Reeve Ingle
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | | | - Bob S. Hu
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
- Palo Alto Medical Foundation, Palo Alto, California, USA
| | - Dwight G. Nishimura
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Taehoon Shin
- Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, Maryland, USA
| |
Collapse
|
44
|
Henningsson M, Hussain T, Vieira MS, Greil GF, Smink J, Ensbergen GV, Beck G, Botnar RM. Whole-heart coronary MR angiography using image-based navigation for the detection of coronary anomalies in adult patients with congenital heart disease. J Magn Reson Imaging 2015; 43:947-55. [PMID: 26451972 DOI: 10.1002/jmri.25058] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 09/15/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The purpose of this study was to evaluate a recently developed two-dimensional (2D) image-based navigation approach (iNAVG+C ) combined with respiratory bellows gating for CMRA in patients with congenital heart disease. METHODS Nine healthy volunteers (mean age 32 ± 6 years [standard deviation]) and 29 patients (28 ± 9 years) were scanned on a 1.5 Tesla clinical scanner using iNAV(G+C) motion compensated T2prepared CMRA, and the conventional 1D NAV approach. Scan time was recorded for each CMRA scan. An image quality score was given to each coronary artery from (0, uninterpretable; to 4, excellent image quality). Additionally, vessel sharpness of each coronary artery was measured. RESULTS Average scan time was significantly shorter (P < 0.01) using the proposed iNAVC+G approach (7:57 ± 1:34) compared with 1D NAV (9:15 ± 3:02). Improved visual scores of the right coronary artery (iNAV(G+C) : 4,3,4 (median, 25th percentile, 75th percentile) versus 1D NAV: 3,3,4; P < 0.001) and left anterior descending artery (iNAV(G+C) : 3,3,4 versus 1D NAV: 3,2,3; P < 0.001) were obtained using iNAV(G+C) compared with 1D NAV as well as an increased vessel sharpness of the right coronary artery (iNAV(G+C) : 65.3% ± 6.6% (mean ± standard deviation) versus 1D NAV: 60.2% ± 11.4%; P < 0.05) and left anterior descending artery (iNAV(G+C) : 63.2% ± 6.7% versus 1D NAV: 58.3% ± 9.5%; P < 0.05). CONCLUSION Image-based navigation in combination with respiratory bellows gating allows for more robust suppression of respiratory motion artifacts for whole-heart CMRA compared with conventional 1D NAV as images can be acquired in a shorter time and with improved image quality.
Collapse
Affiliation(s)
- Markus Henningsson
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Tarique Hussain
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Miguel S Vieira
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | - Gerald F Greil
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| | | | | | | | - Rene M Botnar
- Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom
| |
Collapse
|
45
|
Addy NO, Ingle RR, Wu HH, Hu BS, Nishimura DG. High-resolution variable-density 3D cones coronary MRA. Magn Reson Med 2015; 74:614-21. [PMID: 26172829 DOI: 10.1002/mrm.25803] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 05/16/2015] [Accepted: 05/21/2015] [Indexed: 12/13/2022]
Abstract
PURPOSE To improve the spatial/temporal resolution of whole-heart coronary MR angiography by developing a variable-density (VD) 3D cones acquisition suitable for image reconstruction with parallel imaging and compressed sensing techniques. METHODS A VD 3D cones trajectory design incorporates both radial and spiral trajectory undersampling techniques to achieve higher resolution. This design is used to generate a VD 3D cones trajectory with 0.8 mm/66 ms isotropic spatial/temporal resolution, using a similar number of readouts as our previous fully sampled cones trajectory (1.2 mm/100 ms). Scans of volunteers and patients are performed to evaluate the performance of the VD trajectory, using non-Cartesian L1 -ESPIRiT for high-resolution image reconstruction. RESULTS With gridding reconstruction, the high-resolution scans experience an expected drop in signal-to-noise and contrast-to-noise ratios, but with L1 -ESPIRiT, the apparent noise is substantially reduced. Compared with 1.2 mm images, in each volunteer, the L1 -ESPIRiT 0.8 mm images exhibit higher vessel sharpness values in the right and left anterior descending arteries. CONCLUSION Coronary MR angiography with isotropic submillimeter spatial resolution and high temporal resolution can be performed with VD 3D cones to improve the depiction of coronary arteries.
Collapse
Affiliation(s)
- Nii Okai Addy
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - R Reeve Ingle
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| | - Holden H Wu
- Department of Radiology, University of California, Los Angeles, California, USA
| | - Bob S Hu
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
- Department of Cardiology, Palo Alto Medical Foundation, Palo Alto, California, USA
| | - Dwight G Nishimura
- Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA
| |
Collapse
|
46
|
Whole heart coronary imaging with flexible acquisition window and trigger delay. PLoS One 2015; 10:e0112020. [PMID: 25719750 PMCID: PMC4342264 DOI: 10.1371/journal.pone.0112020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 08/27/2014] [Indexed: 11/18/2022] Open
Abstract
Coronary magnetic resonance imaging (MRI) requires a correctly timed trigger delay derived from a scout cine scan to synchronize k-space acquisition with the quiescent period of the cardiac cycle. However, heart rate changes between breath-held cine and free-breathing coronary imaging may result in inaccurate timing errors. Additionally, the determined trigger delay may not reflect the period of minimal motion for both left and right coronary arteries or different segments. In this work, we present a whole-heart coronary imaging approach that allows flexible selection of the trigger delay timings by performing k-space sampling over an enlarged acquisition window. Our approach addresses coronary motion in an interactive manner by allowing the operator to determine the temporal window with minimal cardiac motion for each artery region. An electrocardiogram-gated, k-space segmented 3D radial stack-of-stars sequence that employs a custom rotation angle is developed. An interactive reconstruction and visualization platform is then employed to determine the subset of the enlarged acquisition window for minimal coronary motion. Coronary MRI was acquired on eight healthy subjects (5 male, mean age = 37 ± 18 years), where an enlarged acquisition window of 166–220 ms was set 50 ms prior to the scout-derived trigger delay. Coronary visualization and sharpness scores were compared between the standard 120 ms window set at the trigger delay, and those reconstructed using a manually adjusted window. The proposed method using manual adjustment was able to recover delineation of five mid and distal right coronary artery regions that were otherwise not visible from the standard window, and the sharpness scores improved in all coronary regions using the proposed method. This paper demonstrates the feasibility of a whole-heart coronary imaging approach that allows interactive selection of any subset of the enlarged acquisition window for a tailored reconstruction for each branch region.
Collapse
|
47
|
Coppo S, Piccini D, Bonanno G, Chaptinel J, Vincenti G, Feliciano H, van Heeswijk RB, Schwitter J, Stuber M. Free-running 4D whole-heart self-navigated golden angle MRI: Initial results. Magn Reson Med 2014; 74:1306-16. [PMID: 25376772 DOI: 10.1002/mrm.25523] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/01/2014] [Accepted: 10/16/2014] [Indexed: 12/22/2022]
Abstract
PURPOSE To test the hypothesis that both coronary anatomy and ventricular function can be assessed simultaneously using a single four-dimensional (4D) acquisition. METHODS A free-running 4D whole-heart self-navigated acquisition incorporating a golden angle radial trajectory was implemented and tested in vivo in nine healthy adult human subjects. Coronary magnetic resonance angiography (MRA) datasets with retrospective selection of acquisition window width and position were extracted and quantitatively compared with baseline self-navigated electrocardiography (ECG) -triggered coronary MRA. From the 4D datasets, the left-ventricular end-systolic, end-diastolic volumes (ESV & EDV) and ejection fraction (EF) were computed and compared with values obtained from conventional 2D cine images. RESULTS The 4D datasets enabled dynamic assessment of the whole heart with isotropic spatial resolution of 1.15 mm(3). Coronary artery image quality was very similar to that of the ECG-triggered baseline scan despite some SNR penalty. A good agreement between 4D and 2D cine imaging was found for EDV, ESV, and EF. CONCLUSION The hypothesis that both coronary anatomy and ventricular function can be assessed simultaneously in vivo has been tested positive. Retrospective and flexible acquisition window selection allows to best visualize each coronary segment at its individual time point of quiescence.
Collapse
Affiliation(s)
- Simone Coppo
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Davide Piccini
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland.,Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland
| | - Gabriele Bonanno
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Jérôme Chaptinel
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Gabriella Vincenti
- Department of Cardiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Hélène Feliciano
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Ruud B van Heeswijk
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Juerg Schwitter
- Department of Cardiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Matthias Stuber
- Center for Biomedical Imaging (CIBM), Lausanne, Switzerland.,Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| |
Collapse
|
48
|
100% Efficient three-dimensional coronary MR angiography with two-dimensional beat-to-beat translational and bin-to-bin affine motion correction. Magn Reson Med 2014; 74:756-64. [DOI: 10.1002/mrm.25460] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 07/31/2014] [Accepted: 08/21/2014] [Indexed: 12/25/2022]
|
49
|
Pang J, Sharif B, Fan Z, Bi X, Arsanjani R, Berman DS, Li D. ECG and navigator-free four-dimensional whole-heart coronary MRA for simultaneous visualization of cardiac anatomy and function. Magn Reson Med 2014; 72:1208-17. [PMID: 25216287 DOI: 10.1002/mrm.25450] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 08/17/2014] [Accepted: 08/22/2014] [Indexed: 11/08/2022]
Abstract
PURPOSE To develop a cardiac and respiratory self-gated four-dimensional (4D) coronary MRA technique for simultaneous cardiac anatomy and function visualization. METHODS A contrast-enhanced, ungated spoiled gradient echo sequence with self-gating (SG) and 3DPR trajectory was used for image acquisition. Data were retrospectively binned into different cardiac and respiratory phases based on information extracted from SG projections using principal component analysis. Each cardiac phase was reconstructed using a respiratory motion-corrected self-calibrating SENSE framework, and those belong to the quiescent period were retrospectively combined for coronary visualization. Healthy volunteer studies were conducted to evaluate the efficacy of the SG method, the accuracy of the left ventricle (LV) function parameters and the quality of coronary artery visualization. RESULTS SG performed reliably for all subjects including one with poor electrocardiogram (ECG). The LV function parameters showed excellent agreement with those from a conventional cine protocol. For coronary imaging, the proposed method yielded comparable apparent signal to noise ratio and coronary sharpness and lower apparent contrast to noise ratio on three subjects compared with an ECG and navigator-gated Cartesian protocol and an ECG-gated, respiratory motion-corrected 3DPR protocol. CONCLUSION A fully self-gated 4D whole-heart imaging technique was developed, potentially allowing cardiac anatomy and function assessment from a single measurement.
Collapse
Affiliation(s)
- Jianing Pang
- Department of Radiology and Biomedical Engineering, Northwestern University, Chicago, Illinois, USA; Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Ingle RR, Santos JM, Overall WR, McConnell MV, Hu BS, Nishimura DG. Self-gated fat-suppressed cardiac cine MRI. Magn Reson Med 2014; 73:1764-74. [PMID: 24806049 DOI: 10.1002/mrm.25291] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 04/15/2014] [Accepted: 04/23/2014] [Indexed: 11/08/2022]
Abstract
PURPOSE To develop a self-gated alternating repetition time balanced steady-state free precession (ATR-SSFP) pulse sequence for fat-suppressed cardiac cine imaging. METHODS Cardiac gating is computed retrospectively using acquired magnetic resonance self-gating data, enabling cine imaging without the need for electrocardiogram (ECG) gating. Modification of the slice-select rephasing gradients of an ATR-SSFP sequence enables the acquisition of a one-dimensional self-gating readout during the unused short repetition time (TR). Self-gating readouts are acquired during every TR of segmented, breath-held cardiac scans. A template-matching algorithm is designed to compute cardiac trigger points from the self-gating signals, and these trigger points are used for retrospective cine reconstruction. The proposed approach is compared with ECG-gated ATR-SSFP and balanced steady-state free precession in 10 volunteers and five patients. RESULTS The difference of ECG and self-gating trigger times has a variability of 13 ± 11 ms (mean ± SD). Qualitative reviewer scoring and ranking indicate no statistically significant differences (P > 0.05) between self-gated and ECG-gated ATR-SSFP images. Quantitative blood-myocardial border sharpness is not significantly different among self-gated ATR-SSFP ( 0.61±0.15 mm -1), ECG-gated ATR-SSFP ( 0.61±0.15 mm -1), or conventional ECG-gated balanced steady-state free precession cine MRI ( 0.59±0.15 mm -1). CONCLUSION The proposed self-gated ATR-SSFP sequence enables fat-suppressed cardiac cine imaging at 1.5 T without the need for ECG gating and without decreasing the imaging efficiency of ATR-SSFP.
Collapse
Affiliation(s)
- R Reeve Ingle
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | | | | | | | | | | |
Collapse
|