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Faulkner ME, Gong Z, Guo A, Laporte JP, Bae J, Bouhrara M. Harnessing myelin water fraction as an imaging biomarker of human cerebral aging, neurodegenerative diseases, and risk factors influencing myelination: A review. J Neurochem 2024. [PMID: 38973579 DOI: 10.1111/jnc.16170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 06/12/2024] [Accepted: 06/19/2024] [Indexed: 07/09/2024]
Abstract
Myelin water fraction (MWF) imaging has emerged as a promising magnetic resonance imaging (MRI) biomarker for investigating brain function and composition. This comprehensive review synthesizes the current state of knowledge on MWF as a biomarker of human cerebral aging, neurodegenerative diseases, and risk factors influencing myelination. The databases used include Web of Science, Scopus, Science Direct, and PubMed. We begin with a brief discussion of the theoretical foundations of MWF imaging, including its basis in MR physics and the mathematical modeling underlying its calculation, with an overview of the most adopted MRI methods of MWF imaging. Next, we delve into the clinical and research applications that have been explored to date, highlighting its advantages and limitations. Finally, we explore the potential of MWF to serve as a predictive biomarker for neurological disorders and identify future research directions for optimizing MWF imaging protocols and interpreting MWF in various contexts. By harnessing the power of MWF imaging, we may gain new insights into brain health and disease across the human lifespan, ultimately informing novel diagnostic and therapeutic strategies.
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Affiliation(s)
- Mary E Faulkner
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Zhaoyuan Gong
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Alex Guo
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - John P Laporte
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Jonghyun Bae
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
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Fahmy AS, Rowin EJ, Arafati A, Al-Otaibi T, Maron MS, Nezafat R. Radiomics and deep learning for myocardial scar screening in hypertrophic cardiomyopathy. J Cardiovasc Magn Reson 2022; 24:40. [PMID: 35761339 PMCID: PMC9235098 DOI: 10.1186/s12968-022-00869-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/08/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Myocardial scar burden quantified using late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR), has important prognostic value in hypertrophic cardiomyopathy (HCM). However, nearly 50% of HCM patients have no scar but undergo repeated gadolinium-based CMR over their life span. We sought to develop an artificial intelligence (AI)-based screening model using radiomics and deep learning (DL) features extracted from balanced steady state free precession (bSSFP) cine sequences to identify HCM patients without scar. METHODS We evaluated three AI-based screening models using bSSFP cine image features extracted by radiomics, DL, or combined DL-Radiomics. Images for 759 HCM patients (50 ± 16 years, 66% men) in a multi-center/vendor study were used to develop and test model performance. An external dataset of 100 HCM patients (53 ± 14 years, 70% men) was used to assess model generalizability. Model performance was evaluated using area-under-receiver-operating curve (AUC). RESULTS The DL-Radiomics model demonstrated higher AUC compared to DL and Radiomics in the internal (0.83 vs 0.77, p = 0.006 and 0.78, p = 0.05; n = 159) and external (0.74 vs 0.64, p = 0.006 and 0.71, p = 0.27; n = 100) datasets. The DL-Radiomics model correctly identified 43% and 28% of patients without scar in the internal and external datasets compared to 42% and 16% by Radiomics model and 42% and 23% by DL model, respectively. CONCLUSIONS A DL-Radiomics AI model using bSSFP cine images outperforms DL or Radiomics models alone as a scar screening tool prior to gadolinium administration. Despite its potential, the clinical utility of the model remains limited and further investigation is needed to improve the accuracy and generalizability.
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Affiliation(s)
- Ahmed S. Fahmy
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215 USA
| | - Ethan J. Rowin
- Cardiovascular Center, Tufts Medical Center, Boston, USA
| | - Arghavan Arafati
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215 USA
| | - Talal Al-Otaibi
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215 USA
| | | | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215 USA
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3
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Magat J, Fouillet A, Constantin M, Haliot K, Naulin J, El Hamrani D, Benoist D, Charron S, Walton R, Bernus O, Quesson B. 3D magnetization transfer (MT) for the visualization of cardiac free-running Purkinje fibers: an ex vivo proof of concept. MAGMA (NEW YORK, N.Y.) 2021; 34:605-618. [PMID: 33484367 PMCID: PMC8338918 DOI: 10.1007/s10334-020-00905-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/02/2020] [Accepted: 12/22/2020] [Indexed: 12/26/2022]
Abstract
OBJECTIVES We investigate the possibility to exploit high-field MRI to acquire 3D images of Purkinje network which plays a crucial role in cardiac function. Since Purkinje fibers (PF) have a distinct cellular structure and are surrounded by connective tissue, we investigated conventional contrast mechanisms along with the magnetization transfer (MT) imaging technique to improve image contrast between ventricular structures of differing macromolecular content. METHODS Three fixed porcine ventricular samples were used with free-running PFs on the endocardium. T1, T2*, T2, and M0 were evaluated on 2D slices for each sample at 9.4 T. MT parameters were optimized using hard pulses with different amplitudes, offset frequencies and durations. The cardiac structure was assessed through 2D and 3D T1w images with isotropic resolutions of 150 µm. Histology, immunofluorescence, and qPCR were performed to analyze collagen contents of cardiac tissue and PF. RESULTS An MT preparation module of 350 ms duration inserted into the sequence with a B1 = 10 µT and frequency offset = 3000 Hz showed the best contrast, approximately 0.4 between PFs and myocardium. Magnetization transfer ratio (MTR) appeared higher in the cardiac tissue (MTR = 44.7 ± 3.5%) than in the PFs (MTR = 25.2 ± 6.3%). DISCUSSION MT significantly improves contrast between PFs and ventricular myocardium and appears promising for imaging the 3D architecture of the Purkinje network.
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Affiliation(s)
- Julie Magat
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France.
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France.
| | - Arnaud Fouillet
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Marion Constantin
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Kylian Haliot
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Jérôme Naulin
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Dounia El Hamrani
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - David Benoist
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Sabine Charron
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Richard Walton
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Olivier Bernus
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
| | - Bruno Quesson
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Foundation Bordeaux Université, Hopital Xavier Arnozan, Avenue du Haut Lévêque, 33604, Pessac cedex, France
- Centre de Recherche Cardio-Thoracique de Bordeaux Inserm, U1045, Université de Bordeaux, 33000, Bordeaux, France
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López K, Neji R, Bustin A, Rashid I, Hajhosseiny R, Malik SJ, Teixeira RPAG, Razavi R, Prieto C, Roujol S, Botnar RM. Quantitative magnetization transfer imaging for non-contrast enhanced detection of myocardial fibrosis. Magn Reson Med 2020; 85:2069-2083. [PMID: 33201524 DOI: 10.1002/mrm.28577] [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: 02/06/2020] [Revised: 09/10/2020] [Accepted: 10/09/2020] [Indexed: 11/09/2022]
Abstract
PURPOSE To develop a novel gadolinium-free model-based quantitative magnetization transfer (qMT) technique to assess macromolecular changes associated with myocardial fibrosis. METHODS The proposed sequence consists of a two-dimensional breath-held dual shot interleaved acquisition of five MT-weighted (MTw) spoiled gradient echo images, with variable MT flip angles (FAs) and off-resonance frequencies. A two-pool exchange model and dictionary matching were used to quantify the pool size ratio (PSR) and bound pool T2 relaxation ( T 2 B ). The signal model was developed and validated using 25 MTw images on a bovine serum albumin (BSA) phantom and in vivo human thigh muscle. A protocol with five MTw images was optimized for single breath-hold cardiac qMT imaging. The proposed sequence was tested in 10 healthy subjects and 5 patients with myocardial fibrosis and compared to late gadolinium enhancement (LGE). RESULTS PSR values in the BSA phantom were within the confidence interval of previously reported values (concentration 10% BSA = 5.9 ± 0.1%, 15% BSA = 9.4 ± 0.2%). PSR and T 2 B in thigh muscle were also in agreement with literature (PSR = 10.9 ± 0.3%, T 2 B = 6.4 ± 0.4 us). In 10 healthy subjects, global left ventricular PSR was 4.30 ± 0.65%. In patients, PSR was reduced in areas associated with LGE (remote: 4.68 ± 0.70% vs. fibrotic: 3.12 ± 0.78 %, n = 5, P < .002). CONCLUSION In vivo model-based qMT mapping of the heart was performed for the first time, with promising results for non-contrast enhanced assessment of myocardial fibrosis.
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Affiliation(s)
- Karina López
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.,MR Research Collaboration, Siemens Healthcare Limited, Frimley, UK
| | - Aurelien Bustin
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Imran Rashid
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Reza Hajhosseiny
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Shaihan J Malik
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Rui Pedro A G Teixeira
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Reza Razavi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Sébastien Roujol
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - René M Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
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López K, Neji R, Mukherjee RK, Whitaker J, Phinikaridou A, Razavi R, Prieto C, Roujol S, Botnar R. Contrast-free high-resolution 3D magnetization transfer imaging for simultaneous myocardial scar and cardiac vein visualization. MAGMA (NEW YORK, N.Y.) 2020; 33:627-640. [PMID: 32078075 PMCID: PMC7502043 DOI: 10.1007/s10334-020-00833-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To develop a three-dimensional (3D) high-resolution free-breathing magnetization transfer ratio (MTR) sequence for contrast-free assessment of myocardial infarct and coronary vein anatomy. MATERIALS AND METHODS Two datasets with and without off-resonance magnetization transfer preparation were sequentially acquired to compute MTR. 2D image navigators enabled beat-to-beat translational and bin-to-bin non-rigid motion correction. Two different imaging sequences were explored. MTR scar localization was compared against 3D late gadolinium enhancement (LGE) in a porcine model of myocardial infarction. MTR variability across the left ventricle and vessel sharpness in the coronary veins were evaluated in healthy human subjects. RESULTS A decrease in MTR was observed in areas with LGE in all pigs (non-infarct: 25.1 ± 1.7% vs infarct: 16.8 ± 1.9%). The average infarct volume overlap on MTR and LGE was 62.5 ± 19.2%. In humans, mean MTR in myocardium was between 37 and 40%. Spatial variability was between 15 and 20% of the mean value. 3D whole heart MT-prepared datasets enabled coronary vein visualization with up to 8% improved vessel sharpness for non-rigid compared to translational motion correction. DISCUSSION MTR and LGE showed agreement in infarct detection and localization in a swine model. Free-breathing 3D MTR maps are feasible in humans but high spatial variability was observed. Further clinical studies are warranted.
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Affiliation(s)
- Karina López
- 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 Limited, Frimley, UK
| | - Rahul K Mukherjee
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor Lambeth Wing, London, SE1 7EH, UK
| | - John Whitaker
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor Lambeth Wing, London, SE1 7EH, UK
| | - Alkystis Phinikaridou
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor Lambeth Wing, London, SE1 7EH, UK
| | - Reza Razavi
- 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
| | - Sébastien Roujol
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor Lambeth Wing, London, SE1 7EH, UK
| | - René Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor Lambeth Wing, London, SE1 7EH, UK
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Diagnostic Accuracy of Mapping Techniques and Postprocessing Methods for Acute Myocarditis. AJR Am J Roentgenol 2020; 215:105-115. [DOI: 10.2214/ajr.19.22028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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7
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Lam B, Stromp TA, Hui Z, Vandsburger M. Myocardial native-T1 times are elevated as a function of hypertrophy, HbA1c, and heart rate in diabetic adults without diffuse fibrosis. Magn Reson Imaging 2019; 61:83-89. [PMID: 31125612 DOI: 10.1016/j.mri.2019.05.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 05/08/2019] [Accepted: 05/20/2019] [Indexed: 12/28/2022]
Abstract
PURPOSE Cardiac native-T1 times have correlated to extracellular volume fraction in patients with confirmed fibrosis. However, whether other factors that can occur either alongside or independently of fibrosis including increased intracellular water volume, altered magnetization transfer (MT), or glycation of hemoglobin, lengthen T1 times in the absence of fibrosis remains unclear. The current study examined whether native-T1 times are elevated in hypertrophic diabetics with elevated hemoglobin A1C (HbA1c) without diffuse fibrosis. METHODS Native-T1 times were quantified in 27 diabetic and 10 healthy adults using a modified Look-Locker imaging (MOLLI) sequence at 1.5 T. The MT ratio (MTR) was quantified using dual flip angle cine balanced steady-state free precession. Gadolinium (0.2 mmol/kg Gd-DTPA) was administered as a bolus and post-contrast T1-times were quantified after 15 min. Means were compared using a two-tailed student's t-test, while correlations were assessed using Pearson's correlations. RESULTS While left ventricular volumes, ejection fraction, and cardiac output were similar between groups, left ventricular mass and mass-to-volume ratio (MVR) were significantly higher in diabetic adults. Mean ECV (0.25 ± 0.02 Healthy vs. 0.25 ± 0.03 Diabetic, P = 0.47) and MTR (125 ± 16% Healthy vs. 125 ± 9% Diabetic, P = 0.97) were similar, however native-T1 times were significantly higher in diabetics (1016 ± 21 ms Healthy vs. 1056 ± 31 ms Diabetic, P = 0.00051). Global native-T1 times correlated with MVR (ρ = 0.43, P = 0.008) and plasma HbA1c levels (ρ = 0.43, P = 0.0088) but not ECV (ρ = 0.06, P = 0.73). Septal native-T1 times correlated with septal wall thickness (ρ = 0.50, P = 0.001). CONCLUSION In diabetic adults with normal ECV values, elevated native-T1 times may reflect increased intracellular water volume and changes secondary to increased hemoglobin glycation.
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Affiliation(s)
- Bonnie Lam
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA
| | - Tori A Stromp
- Department of Physiology, University of Kentucky, Lexington, KY 40506, USA
| | - Zhengxiong Hui
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA
| | - Moriel Vandsburger
- Department of Bioengineering, University of California, Berkeley, CA 94720, USA.
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Duan C, Zhu Y, Jang J, Rodriguez J, Neisius U, Fahmy AS, Nezafat R. Non-contrast myocardial infarct scar assessment using a hybrid native T 1 and magnetization transfer imaging sequence at 1.5T. Magn Reson Med 2018; 81:3192-3201. [PMID: 30565296 DOI: 10.1002/mrm.27636] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE To develop a gadolinium-free cardiac MR technique that simultaneously exploits native T1 and magnetization transfer (MT) contrast for the imaging of myocardial infarction. METHODS A novel hybrid T one and magnetization transfer (HYTOM) method was developed based on the modified look-locker inversion recovery (MOLLI) sequence, with a train of MT-prep pulses placed before the balanced SSFP (bSSFP) readout pulses. Numerical simulations, based on Bloch-McConnell equations, were performed to investigate the effects of MT induced by (1) the bSSFP readout pulses, and (2) the MT-prep pulses, on the measured, "apparent," native T1 values. The HYTOM method was then tested on 8 healthy adult subjects, 6 patients, and a swine with prior myocardial infarction (MI). The resulting imaging contrast between normal myocardium and infarcted tissues was compared with that of MOLLI. Late gadolinium enhancement (LGE) images were also obtained for infarct assessment in patients and swine. RESULTS Numerical simulation and in vivo studies in healthy volunteers demonstrated that MT effects, resulting from on-resonance bSSFP excitation pulses and off-resonance MT-prep pulses, reduce the measured T1 in both MOLLI and HTYOM. In vivo studies in patients and swine showed that the HYTOM sequence can identify locations of MI, as seen on LGE. Furthermore, the HYTOM method yields higher myocardium-to-scar contrast than MOLLI (contrast-to-noise ratio: 7.33 ± 1.67 vs. 3.77 ± 0.66, P < 0.01). CONCLUSION The proposed HYTOM method simultaneously exploits native T1 and MT contrast and significantly boosts the imaging contrast for myocardial infarction.
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Affiliation(s)
- Chong Duan
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Yanjie Zhu
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Jihye Jang
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts.,Department of Computer Science, Technical University of Munich, Munich, Germany
| | - Jennifer Rodriguez
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Ulf Neisius
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Ahmed S Fahmy
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
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9
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Shaw JL, Yang Q, Zhou Z, Deng Z, Nguyen C, Li D, Christodoulou AG. Free-breathing, non-ECG, continuous myocardial T 1 mapping with cardiovascular magnetic resonance multitasking. Magn Reson Med 2018; 81:2450-2463. [PMID: 30450749 DOI: 10.1002/mrm.27574] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 09/14/2018] [Accepted: 09/28/2018] [Indexed: 01/24/2023]
Abstract
PURPOSE To evaluate the accuracy and repeatability of a free-breathing, non-electrocardiogram (ECG), continuous myocardial T1 and extracellular volume (ECV) mapping technique adapted from the Multitasking framework. METHODS The Multitasking framework is adapted to quantify both myocardial native T1 and ECV with a free-breathing, non-ECG, continuous acquisition T1 mapping method. We acquire interleaved high-spatial resolution image data and high-temporal resolution auxiliary data following inversion-recovery pulses at set intervals and perform low-rank tensor imaging to reconstruct images at 344 inversion times, 20 cardiac phases, and 6 respiratory phases. The accuracy and repeatability of Multitasking T1 mapping in generating native T1 and ECV maps are compared with conventional techniques in a phantom, a simulation, 12 healthy subjects, and 10 acute myocardial infarction patients. RESULTS In phantoms, Multitasking T1 mapping correlated strongly with the gold-standard spin-echo inversion recovery (R2 = 0.99). A simulation study demonstrated that Multitasking T1 mapping has similar myocardial sharpness to the fully sampled ground truth. In vivo native T1 and ECV values from Multitasking T1 mapping agree well with conventional MOLLI values and show good repeatability for native T1 and ECV mapping for 60 seconds, 30 seconds, or 15 seconds of data. Multitasking native T1 and ECV in myocardial infarction patients correlate positively with values from MOLLI. CONCLUSION Multitasking T1 mapping can quantify native T1 and ECV in the myocardium with free-breathing, non-ECG, continuous scans with good image quality and good repeatability in vivo in healthy subjects, and correlation with MOLLI T1 and ECV in acute myocardial infarction patients.
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Affiliation(s)
- Jaime L Shaw
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California.,Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Qi Yang
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Radiology, Xuanwu Hospital, Beijing, China
| | - Zhengwei Zhou
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Zixin Deng
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California
| | - Christopher Nguyen
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
| | - Debiao Li
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, California
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Detection of Recent Myocardial Infarction Using Native T1 Mapping in a Swine Model: A Validation Study. Sci Rep 2018; 8:7391. [PMID: 29743511 PMCID: PMC5943450 DOI: 10.1038/s41598-018-25693-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 04/24/2018] [Indexed: 11/22/2022] Open
Abstract
Late gadolinium enhancement (LGE) imaging is the currently the gold standard for in-vivo detection of myocardial infarction. However, gadolinium contrast administration is contraindicated in patients with renal insufficiency. We aim to evaluate the diagnostic sensitivity and specificity of this contrast-free MRI technique, native T1 mapping, in detecting recent myocardial infarction versus a reference histological gold standard. Ten pigs underwent CMR at 2 weeks after induced MI. The infarct size and transmural extent of MI was calculated using native T1 maps and LGE images. Histological validation was performed using triphenyl tetrazolium chloride (TTC) staining in the corresponding ex-vivo slices. The infarct size and transmural extent of myocardial infarction assessed by T1 mapping correlated well with that assessed by LGE and TTC images. Using TTC staining as the reference, T1 mapping demonstrated underestimation of infarct size and transmural extent of infarction. Additionally, there was a slight but not significant difference found in the diagnostic performance between the native T1 maps and LGE images for the location of MI. Our study shows that native T1 mapping is feasible alternative method to the LGE technique for the assessment of the size, transmural extent, and location of MI in patients who cannot receive gadolinium contrast.
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Xanthis CG, Bidhult S, Greiser A, Chow K, Thompson RB, Arheden H, Aletras AH. Simulation-based quantification of native T1 and T2 of the myocardium using a modified MOLLI scheme and the importance of Magnetization Transfer. Magn Reson Imaging 2018; 48:96-106. [DOI: 10.1016/j.mri.2017.12.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 12/12/2017] [Accepted: 12/21/2017] [Indexed: 12/18/2022]
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Germain P, El Ghannudi S, Labani A, Jeung MY, Gangi A, Ohlmann P, Roy C. A dual flip angle 3D bSSFP magnetization transfer-like method to differentiate between recent and old myocardial infarction. J Magn Reson Imaging 2017; 47:798-808. [PMID: 28727209 DOI: 10.1002/jmri.25821] [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: 05/09/2017] [Accepted: 07/07/2017] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Magnetic resonance imaging (MRI) tissue signal is modulated by magnetization transfer (MT) phenomena, intrinsically induced by balanced steady-state free precession (bSSFP) imaging. PURPOSE To investigate the possible value of such a MT-like bSSFP approach in two clinical settings involving focal myocardial lesions highligthed by late gadolinium enhancement (LGE+): edema induced by recent myocardial infarction (MI) and fibrotic scar related to chronic infarction. MATERIALS AND METHODS Population: 48 LGE + patients were studied: 26 with recent MI, 22 with chronic MI. 20 LGE-normal subjects were considered the control group. Field strength/sequence: Navigator-based short axis 3D-bSSFP sequences with 20° and 90° excitation flip angles were acquired (1.5T). ASSESSMENT Pixel-wise normalized MT Ratio (nMTR) parametric images were calculated according to: nMTR = 100*(S20 -S90 *k)/S20 , with S20 and S90 signal intensity in 20° and 90° flip angle images and k = Blood20 /Blood90 as a normalization ratio. Statistical tests: analysis of variance (ANOVA), receiver operating characteristic (ROC) analysis. RESULTS Overall normal myocardial nMTR was 50.2 ± 3.6%. In recent MI, nMTR values were significantly reduced in LGE + regions (-22.3 ± 9.9%, P < 0.0001). In cases of chronic infarct, nMTR was significantly increased in LGE + regions (14.2 ± 11.4%, P < 0.0001). Comparison between observed results and theoretical values obtained with the Freeman-Hill formula showed that most variations observed in MI are related to MT effects instead of relaxation effects. CONCLUSION In contrast to LGE imaging, which may show a similar hyperenhancement in recent and old infarctions, nMTR imaging demonstrates an opposite pattern: decreased values for recent infarction and increased values for old infarction, thus allowing to discriminate between these two clinical conditions without gadolinium injection. LEVEL OF EVIDENCE 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:798-808.
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Affiliation(s)
- Philippe Germain
- Department of Radiology, University Hospital, Strasbourg, France.,Department of Cardiology, University Hospital, Strasbourg, France
| | - Soraya El Ghannudi
- Department of Radiology, University Hospital, Strasbourg, France.,Department of Nuclear Medicine, University Hospital, Strasbourg, France
| | - Aissam Labani
- Department of Radiology, University Hospital, Strasbourg, France
| | - Mi Y Jeung
- Department of Radiology, University Hospital, Strasbourg, France
| | - Afshin Gangi
- Department of Radiology, University Hospital, Strasbourg, France
| | - Patrick Ohlmann
- Department of Cardiology, University Hospital, Strasbourg, France
| | - Catherine Roy
- Department of Radiology, University Hospital, Strasbourg, France
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Bouhrara M, Spencer RG. Rapid simultaneous high-resolution mapping of myelin water fraction and relaxation times in human brain using BMC-mcDESPOT. Neuroimage 2016; 147:800-811. [PMID: 27729276 DOI: 10.1016/j.neuroimage.2016.09.064] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 08/21/2016] [Accepted: 09/26/2016] [Indexed: 10/20/2022] Open
Abstract
A number of central nervous system (CNS) diseases exhibit changes in myelin content and magnetic resonance longitudinal, T1, and transverse, T2, relaxation times, which therefore represent important biomarkers of CNS pathology. Among the methods applied for measurement of myelin water fraction (MWF) and relaxation times, the multicomponent driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) approach is of particular interest. mcDESPOT permits whole brain mapping of multicomponent T1 and T2, with data acquisition accomplished within a clinically realistic acquisition time. Unfortunately, previous studies have indicated the limited performance of mcDESPOT in the setting of the modest signal-to-noise range of high-resolution mapping, required for the depiction of small structures and to reduce partial volume effects. Recently, we showed that a new Bayesian Monte Carlo (BMC) analysis substantially improved determination of MWF from mcDESPOT imaging data. However, our previous study was limited in that it did not discuss determination of relaxation times. Here, we extend the BMC analysis to the simultaneous determination of whole-brain MWF and relaxation times using the two-component mcDESPOT signal model. Simulation analyses and in-vivo human brain studies indicate the overall greater performance of this approach compared to the stochastic region contraction (SRC) algorithm, conventionally used to derive parameter estimates from mcDESPOT data. SRC estimates of the transverse relaxation time of the long T2 fraction, T2,l, and the longitudinal relaxation time of the short T1 fraction, T1,s, clustered towards the lower and upper parameter search space limits, respectively, indicating failure of the fitting procedure. We demonstrate that this effect is absent in the BMC analysis. Our results also showed improved parameter estimation for BMC as compared to SRC for high-resolution mapping. Overall we find that the combination of BMC analysis and mcDESPOT, BMC-mcDESPOT, shows excellent performance for accurate high-resolution whole-brain mapping of MWF and bi-component transverse and longitudinal relaxation times within a clinically realistic acquisition time.
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Affiliation(s)
- Mustapha Bouhrara
- Magnetic Resonance Imaging and Spectroscopy Section, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Intramural Research Program, BRC 04B-116, 251 Bayview Boulevard, Baltimore, MD 21224, USA.
| | - Richard G Spencer
- Magnetic Resonance Imaging and Spectroscopy Section, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Intramural Research Program, BRC 04B-116, 251 Bayview Boulevard, Baltimore, MD 21224, USA.
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Xanthis CG, Bidhult S, Kantasis G, Heiberg E, Arheden H, Aletras AH. Parallel simulations for QUAntifying RElaxation magnetic resonance constants (SQUAREMR): an example towards accurate MOLLI T1 measurements. J Cardiovasc Magn Reson 2015; 17:104. [PMID: 26610703 PMCID: PMC4662017 DOI: 10.1186/s12968-015-0206-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 11/15/2015] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND T1 mapping is widely used today in CMR, however, it underestimates true T1 values and its measurement error is influenced by several acquisition parameters. The purpose of this study was the extraction of accurate T1 data through the utilization of comprehensive, parallel Simulations for QUAntifying RElaxation Magnetic Resonance constants (SQUAREMR) of the MOLLI pulse sequence on a large population of spins with physiologically relevant tissue relaxation constants. METHODS A CMR protocol consisting of different MOLLI schemes was performed on phantoms and healthy human volunteers. For every MOLLI experiment, the identical pulse sequence was simulated for a large range of physiological combinations of relaxation constants, resulting in a database of all possible outcomes. The unknown relaxation constants were then determined by finding the simulated signals in the database that produced the least squared difference to the measured signal intensities. RESULTS SQUAREMR demonstrated improvement of accuracy in phantom studies and consistent mean T1 values and consistent variance across the different MOLLI schemes in humans. This was true even for tissues with long T1s and MOLLI schemes with no pause between modified-Look-Locker experiments. CONCLUSIONS SQUAREMR enables quantification of T1 data obtained by existing clinical pulse sequences. SQUAREMR allows for correction of quantitative CMR data that have already been acquired whereas it is expected that SQUAREMR may improve data consistency and advance quantitative MR across imaging centers, vendors and experimental configurations. While this study is focused on a MOLLI-based T1-mapping technique, it could however be extended in other types of quantitative MRI throughout the body.
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Affiliation(s)
- Christos G Xanthis
- Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital Lund, Lund University, Lund, Sweden.
- Department of Computer Science and Biomedical Informatics, University of Thessaly, Lamia, Greece.
| | - Sebastian Bidhult
- Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital Lund, Lund University, Lund, Sweden.
| | - George Kantasis
- Laboratory of Computing and Medical Informatics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Einar Heiberg
- Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital Lund, Lund University, Lund, Sweden.
- Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
- Centre of Mathematical Sciences, Faculty of Engineering, Lund University, Lund, Sweden.
| | - Håkan Arheden
- Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital Lund, Lund University, Lund, Sweden.
| | - Anthony H Aletras
- Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital Lund, Lund University, Lund, Sweden.
- Laboratory of Computing and Medical Informatics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Stromp TA, Leung SW, Andres KN, Jing L, Fornwalt BK, Charnigo RJ, Sorrell VL, Vandsburger MH. Gadolinium free cardiovascular magnetic resonance with 2-point Cine balanced steady state free precession. J Cardiovasc Magn Reson 2015; 17:90. [PMID: 26520782 PMCID: PMC4628395 DOI: 10.1186/s12968-015-0194-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 10/09/2015] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Cardiovascular magnetic resonance (CMR) of ventricular structure and function is widely performed using cine balanced steady state free precession (bSSFP) MRI. The bSSFP signal of myocardium is weighted by magnetization transfer (MT) and T1/T2-relaxation times. In edematous and fibrotic tissues, increased T2 and reduced MT lead to increased signal intensity on images acquired with high excitation flip angles. We hypothesized that acquisition of two differentially MT-weighted bSSFP images (termed 2-point bSSFP) can identify tissue that would enhance with gadolinium similar to standard of care late gadolinium enhancement (LGE). METHODS Cine bSSFP images (flip angles of 5° and 45°) and native-T1 and T2 maps were acquired in one mid-ventricular slice in 47 patients referred for CMR and 10 healthy controls. Afterwards, LGE images and post-contrast T1 maps were acquired and gadolinium partition coefficient (GPC) was calculated. Maps of ΔS/So were calculated as (S45-S5)/S5*100 (%), where Sflip_angle is the voxel signal intensity. RESULTS Twenty three patients demonstrated areas of myocardial hyper-enhancement with LGE. In enhanced regions, ΔS/So, native-T1, T2, and GPC were heightened (p < 0.05 vs. non-enhanced tissues). ΔS/So, native-T1, and T2 all demonstrated association with GPC, however the association was strongest for ΔS/So. Bland-Altman analysis revealed a slight bias towards larger volume of enhancement with ΔS/So compared to LGE, and similar transmurality. Subjective analysis with 2-blinded expert readers revealed agreement between ΔS/So and LGE of 73.4 %, with false positive detection of 16.7 % and false negative detection of 15.2 %. CONCLUSIONS Gadolinium free 2-point bSSFP identified tissue that enhances at LGE with strong association to GPC. Our results suggest that with further development, MT-weighted CMR could be used similar to LGE for diagnostic imaging.
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Affiliation(s)
- Tori A Stromp
- Department of Physiology, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
| | - Steve W Leung
- Gill Heart Institute, University of Kentucky Healthcare, Lexington, KY, USA.
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
| | - Kristin N Andres
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
| | - Linyuan Jing
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
- Department of Pediatrics, University of Kentucky Healthcare, Lexington, KY, USA.
| | - Brandon K Fornwalt
- Department of Physiology, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
- Department of Pediatrics, University of Kentucky Healthcare, Lexington, KY, USA.
- Department of Biomedical Engineering, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
| | - Richard J Charnigo
- Departments of Statistics and Biostatistics, University of Kentucky, Lexington, KY, USA.
| | - Vincent L Sorrell
- Gill Heart Institute, University of Kentucky Healthcare, Lexington, KY, USA.
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
| | - Moriel H Vandsburger
- Department of Physiology, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
- Saha Cardiovascular Research Center, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
- Department of Biomedical Engineering, University of Kentucky, 741 South Limestone Street, BBSRB room 355, Lexington, 40536, KY, USA.
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Siu AG, Ramadeen A, Hu X, Morikawa L, Zhang L, Lau JYC, Liu G, Pop M, Connelly KA, Dorian P, Wright GA. Characterization of the ultrashort-TE (UTE) MR collagen signal. NMR IN BIOMEDICINE 2015; 28:1236-1244. [PMID: 26268158 DOI: 10.1002/nbm.3372] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/26/2015] [Accepted: 07/16/2015] [Indexed: 06/04/2023]
Abstract
Although current cardiovascular MR (CMR) techniques for the detection of myocardial fibrosis have shown promise, they nevertheless depend on gadolinium-based contrast agents and are not specific to collagen. In particular, the diagnosis of diffuse myocardial fibrosis, a precursor of heart failure, would benefit from a non-invasive imaging technique that can detect collagen directly. Such a method could potentially replace the need for endomyocardial biopsy, the gold standard for the diagnosis of the disease. The objective of this study was to measure the MR properties of collagen using ultrashort TE (UTE), a technique that can detect short T2* species. Experiments were performed in collagen solutions. Via a model of bi-exponential T2* with oscillation, a linear relationship (slope = 0.40 ± 0.01, R(2) = 0.99696) was determined between the UTE collagen signal fraction associated with these properties and the measured collagen concentration in solution. The UTE signal of protons in the collagen molecule was characterized as having a mean T2* of 0.75 ± 0.05 ms and a mean chemical shift of -3.56 ± 0.01 ppm relative to water at 7 T. The results indicated that collagen can be detected and quantified using UTE. A knowledge of the collagen signal properties could potentially be beneficial for the endogenous detection of myocardial fibrosis.
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Affiliation(s)
- Adrienne G Siu
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Andrew Ramadeen
- Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada
| | - Xudong Hu
- Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada
| | - Lily Morikawa
- Center for Modeling Human Disease, Toronto Center for Phenogenomics, Toronto, ON, Canada
| | - Li Zhang
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Justin Y C Lau
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Garry Liu
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Mihaela Pop
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Kim A Connelly
- Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada
- Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada
- Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada
| | - Paul Dorian
- Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada
- Keenan Research Center, Li Ka Shing Knowledge Institute, Toronto, ON, Canada
- Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada
| | - Graham A Wright
- Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
- Cardiovascular Sciences Collaborative Program, University of Toronto, Toronto, ON, Canada
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada
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Native T1 Mapping by 3-T CMR Imaging for Characterization of Chronic Myocardial Infarctions. JACC Cardiovasc Imaging 2015; 8:1019-1030. [PMID: 26298071 DOI: 10.1016/j.jcmg.2015.04.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/26/2015] [Accepted: 04/29/2015] [Indexed: 01/03/2023]
Abstract
OBJECTIVES The purpose of this study was to investigate whether native T1 maps at 3-T can reliably characterize chronic myocardial infarctions (MIs) in patients with prior ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI). BACKGROUND Late gadolinium enhancement (LGE) cardiac magnetic resonance is the gold standard for characterizing chronic MIs, but it is contraindicated in patients with end-stage chronic kidney disease. METHODS Native T1 and LGE images were acquired at 3-T in patients with prior STEMI (n = 13) and NSTEMI (n = 12) at a median of 13.6 years post-MI. Infarct location, size, and transmurality were measured using mean ± 5 SDs thresholding criterion from LGE images and T1 maps and compared against one another. Independent reviewers assessed visual conspicuity of MIs on LGE images and T1 maps. RESULTS Native T1 maps and LGE images were not different for measuring infarct size (STEMI: p = 0.46; NSTEMI: p = 0.27) and transmurality (STEMI: p = 0.13; NSTEMI: p = 0.21) using thresholding criterion. Using thresholding criterion, good agreement was observed between LGE images and T1 maps for measuring infarct size (STEMI: bias = 0.6 ± 3.1%; R(2) = 0.93; NSTEMI: bias = -0.4 ± 4.4%; R(2) = 0.85) and transmurality (STEMI: bias = 2.0 ± 4.2%; R(2) = 0.89; NSTEMI: bias = -2.7 ± 7.9%; R(2) = 0.68). Sensitivity and specificity of T1 maps for detecting chronic MIs based on thresholding criterion were 89% and 98%, respectively (STEMI), and 87% and 95%, respectively (NSTEMI). Relative to LGE images, the mean visual conspicuity score for detecting chronic MIs was significantly lower for T1 maps (p < 0.001 for both cases). Median infarct-to-remote myocardium contrast-to-noise ratio was 2.5-fold higher for LGE images relative to T1 maps (p < 0.001). Sensitivity and specificity of T1 maps for visual detection were 60% and 86%, respectively (STEMI), and 64% and 91% (NSTEMI), respectively. CONCLUSIONS Chronic MIs in STEMI and NSTEMI patients can be reliably characterized using threshold-based detection on native T1 maps at 3-T. Visual detection of chronic MIs on native T1 maps in both patient populations has high specificity, but modest sensitivity.
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Bakermans AJ, Abdurrachim D, Moonen RPM, Motaal AG, Prompers JJ, Strijkers GJ, Vandoorne K, Nicolay K. Small animal cardiovascular MR imaging and spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2015; 88-89:1-47. [PMID: 26282195 DOI: 10.1016/j.pnmrs.2015.03.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
The use of MR imaging and spectroscopy for studying cardiovascular disease processes in small animals has increased tremendously over the past decade. This is the result of the remarkable advances in MR technologies and the increased availability of genetically modified mice. MR techniques provide a window on the entire timeline of cardiovascular disease development, ranging from subtle early changes in myocardial metabolism that often mark disease onset to severe myocardial dysfunction associated with end-stage heart failure. MR imaging and spectroscopy techniques play an important role in basic cardiovascular research and in cardiovascular disease diagnosis and therapy follow-up. This is due to the broad range of functional, structural and metabolic parameters that can be quantified by MR under in vivo conditions non-invasively. This review describes the spectrum of MR techniques that are employed in small animal cardiovascular disease research and how the technological challenges resulting from the small dimensions of heart and blood vessels as well as high heart and respiratory rates, particularly in mice, are tackled.
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Affiliation(s)
- Adrianus J Bakermans
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Desiree Abdurrachim
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rik P M Moonen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Abdallah G Motaal
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Gustav J Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands; Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Katrien Vandoorne
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
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Bouhrara M, Reiter DA, Celik H, Fishbein KW, Kijowski R, Spencer RG. Analysis of mcDESPOT- and CPMG-derived parameter estimates for two-component nonexchanging systems. Magn Reson Med 2015; 75:2406-20. [PMID: 26140371 DOI: 10.1002/mrm.25801] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/06/2015] [Accepted: 05/18/2015] [Indexed: 02/06/2023]
Abstract
PURPOSE To compare the reliability and stability of the multicomponent-driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) and Carl-Purcell-Meiboom-Gill (CPMG) approaches to parameter estimation. METHODS The stability and reliability of mcDESPOT and CPMG-derived parameter estimates were compared through examination of energy surfaces, evaluation of model sloppiness, and Monte Carlo simulations. Comparisons were performed on an equal time basis and assuming a two-component system. Parameter estimation bias, reflecting accuracy, and dispersion, reflecting precision, were derived for a range of signal-to-noise ratios (SNRs) and relaxation parameters. RESULTS The energy surfaces for parameters incorporated into the mcDESPOT signal model exhibit flatness, a complex structure of local minima, and instability to noise to a much greater extent than the corresponding surfaces for CPMG. Although both mcDESPOT and CPMG performed well at high SNR, the CPMG approach yielded parameter estimates of considerably greater accuracy and precision at lower SNR. CONCLUSION mcDESPOT and CPMG both permit high-quality parameter estimates under SNR that are clinically achievable under many circumstances, depending upon available hardware and resolution and acquisition time constraints. At moderate to high SNR, the mcDESPOT approach incorporating two-step phase increments can yield accurate parameter estimates while providing values for longitudinal relaxation times that are not available through CPMG. However, at low SNR, the CPMG approach is more stable and provides superior parameter estimates. Magn Reson Med 75:2406-2420, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - David A Reiter
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Hasan Celik
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Kenneth W Fishbein
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
| | - Richard Kijowski
- Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA
| | - Richard G Spencer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
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Vandsburger M, Vandoorne K, Oren R, Leftin A, Mpofu S, Delli Castelli D, Aime S, Neeman M. Cardio-chemical exchange saturation transfer magnetic resonance imaging reveals molecular signatures of endogenous fibrosis and exogenous contrast media. Circ Cardiovasc Imaging 2014; 8:CIRCIMAGING.114.002180. [PMID: 25550399 DOI: 10.1161/circimaging.114.002180] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Application of emerging molecular MRI techniques, including chemical exchange saturation transfer (CEST)-MRI, to cardiac imaging is desirable; however, conventional methods are poorly suited for cardiac imaging, particularly in small animals with rapid heart rates. We developed a CEST-encoded steady state and retrospectively gated cardiac cine imaging sequence in which the presence of fibrosis or paraCEST contrast agents was directly encoded into the steady-state myocardial signal intensity (cardioCEST). METHODS AND RESULTS Development of cardioCEST: A CEST-encoded cardiac cine MRI sequence was implemented on a 9.4T small animal scanner. CardioCEST of fibrosis was serially performed by acquisition of a series of CEST-encoded cine images at multiple offset frequencies in mice (n=7) after surgically induced myocardial infarction. Scar formation was quantified using a spectral modeling approach and confirmed with histological staining. Separately, circulatory redistribution kinetics of the paramagnetic CEST agent Eu-HPDO3A were probed in mice using cardioCEST imaging, revealing rapid myocardial redistribution, and washout within 30 minutes (n=6). Manipulation of vascular tone resulted in heightened peak CEST contrast in the heart, but did not alter redistribution kinetics (n=6). At 28 days after myocardial infarction (n=3), CEST contrast kinetics in infarct zone tissue were altered, demonstrating gradual accumulation of Eu-HPDO3A in the increased extracellular space. CONCLUSIONS cardioCEST MRI enables in vivo imaging of myocardial fibrosis using endogenous contrast mechanisms, and of exogenously delivered paraCEST agents, and can enable multiplexed imaging of multiple molecular targets at high-resolution coupled with conventional cardiac MRI scans.
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Affiliation(s)
- Moriel Vandsburger
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Katrien Vandoorne
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Roni Oren
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Avigdor Leftin
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Senzeni Mpofu
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Daniela Delli Castelli
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Silvio Aime
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.)
| | - Michal Neeman
- From the Departments of Biological Regulation (M.V., K.V., R.O., S.M., M.N.) and Chemical Physics (A.L.), Weizmann Institute of Science, Rehovot, Israel; Department of Physiology and Biomedical Engineering, University of Kentucky, Lexington (M.V.); and Molecular Biotechnology Center, University of Torino, Torino, Italy (D.D.C., S.A.).
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21
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Comparison between balanced steady-state free precession and standard spoiled gradient echo magnetization transfer ratio imaging in multiple sclerosis: methodical and clinical considerations. Neuroimage 2014; 108:87-94. [PMID: 25536494 DOI: 10.1016/j.neuroimage.2014.12.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 12/12/2014] [Accepted: 12/16/2014] [Indexed: 11/22/2022] Open
Abstract
Different pathological processes like demyelination and axonal loss can alter the magnetisation transfer ratio (MTR) in brain tissue. The standard method to measure this effect is to scan the respective tissue twice, one with and one without a specific saturation pulse. A major drawback of this technique based on spoiled gradient echo (GRE) sequences relates to its long acquisition time due to the saturation pulses. Recently, an alternative concept for MT imaging based on balanced steady state free precession (bSSFP) has been proposed. Modification of the duration of the radiofrequency pulses for imaging allows scanning MT sensitive and non-sensitive images. The steady-state character of bSSFP with high intrinsic signal-to-noise ratio (SNR) allows three-dimensional (3D) whole brain MTR at high spatial resolution within short and thus clinically feasible acquisition times. In the present study, both bSSFP-MT and 2D GRE-MT imaging were used in a cohort of 31 patients with multiple sclerosis (MS) to characterize different normal appearing (NA) and pathological brain structures. Under the constraint of identical SNR and scan time, a 3.4 times higher voxel size could be achieved with bSSFP. This increased resolution allowed a more accurate delineation of the different brain structures, especially of cortex, hippocampus and MS lesions. In a multiple linear regression model, we found an association between MTR of cortical lesions and a clinical measure of disability (r= -0.407, p=0.035) in the bSSFP dataset only. The different relaxation weighting of the base images (T2/T1 in bSSFP, proton density in GRE) had no effects besides a larger spreading of the MTR values of the different NA structures. This was demonstrated by the nearly perfect linearity between the NA matter MTR of both techniques as well as in the absolute MTR differences between NA matter and the respective lesions.
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22
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van Oorschot JW, Gho JM, van Hout GP, Froeling M, Jansen of Lorkeers SJ, Hoefer IE, Doevendans PA, Luijten PR, Chamuleau SA, Zwanenburg JJ. Endogenous contrast MRI of cardiac fibrosis: Beyond late gadolinium enhancement. J Magn Reson Imaging 2014; 41:1181-9. [DOI: 10.1002/jmri.24715] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 12/27/2022] Open
Affiliation(s)
| | - Johannes M.I.H. Gho
- Department of Cardiology; University Medical Center Utrecht; Utrecht The Netherlands
| | | | - Martijn Froeling
- Department of Radiology; University Medical Center Utrecht; Utrecht The Netherlands
| | | | - Imo E. Hoefer
- Department of Cardiology; University Medical Center Utrecht; Utrecht The Netherlands
| | - Pieter A. Doevendans
- Department of Cardiology; University Medical Center Utrecht; Utrecht The Netherlands
| | - Peter R. Luijten
- Department of Radiology; University Medical Center Utrecht; Utrecht The Netherlands
| | - Steven A.J. Chamuleau
- Department of Cardiology; University Medical Center Utrecht; Utrecht The Netherlands
| | - Jaco J.M. Zwanenburg
- Department of Radiology; University Medical Center Utrecht; Utrecht The Netherlands
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23
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Kali A, Cokic I, Tang RLQ, Yang HJ, Sharif B, Marbán E, Li D, Berman DS, Dharmakumar R. Determination of location, size, and transmurality of chronic myocardial infarction without exogenous contrast media by using cardiac magnetic resonance imaging at 3 T. Circ Cardiovasc Imaging 2014; 7:471-81. [PMID: 24682268 DOI: 10.1161/circimaging.113.001541] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Late-gadolinium-enhanced (LGE) cardiac MRI (CMR) is a powerful method for characterizing myocardial infarction (MI), but the requisite gadolinium infusion is estimated to be contraindicated in ≈20% of patients with MI because of end-stage chronic kidney disease. The purpose of this study is to investigate whether T1 CMR obtained without contrast agents at 3 T could be an alternative to LGE CMR for characterizing chronic MIs using a canine model of MI. METHODS AND RESULTS Canines (n=29) underwent CMR at 7 days (acute MI [AMI]) and 4 months (chronic MI [CMI]) after MI. Infarct location, size, and transmurality measured by using native T1 maps and LGE images at 1.5 T and 3 T were compared. Resolution of edema between AMI and CMI was examined with T2 maps. T1 maps overestimated infarct size and transmurality relative to LGE images in AMI (P=0.016 and P=0.007, respectively), which was not observed in CMI (P=0.49 and P=0.81, respectively) at 3 T. T1 maps underestimated infarct size and transmurality relative to LGE images in AMI and CMI (P<0.001) at 1.5 T. Relative to the remote territories, T1 of the infarcted myocardium was increased in CMI and AMI (P<0.05), and T2 of the infarcted myocardium was increased in AMI (P<0.001) but not in CMI (P>0.20) at both field strengths. Histology showed extensive replacement fibrosis within the CMI territories. CMI detection sensitivity and specificity of T1 CMR at 3 T were 95% and 97%, respectively. CONCLUSIONS Native T1 maps at 3 T can determine the location, size, and transmurality of CMI with high diagnostic accuracy. Patient studies are necessary for clinical translation.
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Affiliation(s)
- Avinash Kali
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Ivan Cokic
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Richard L Q Tang
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Hsin-Jung Yang
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Behzad Sharif
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Eduardo Marbán
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Debiao Li
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Daniel S Berman
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.)
| | - Rohan Dharmakumar
- From the Biomedical Imaging Research Institute, Department of Biomedical Sciences (A.K., I.C., R.L.Q.T., H.-J.Y., B.S., D.L., R.D.) and Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (E.M., D.L., D. S. B., R.D.); Department of Bioengineering (A.K., H.-J.Y.) and Department of Medicine, David Geffen School of Medicine (D. S. B., R.D.), University of California, Los Angeles, CA; and Department of Radiology, Northwestern University, Chicago, IL (A.K., R.L.Q.T., D.L., R.D.).
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Review of T1 Mapping Methods: Comparative Effectiveness Including Reproducibility Issues. CURRENT CARDIOVASCULAR IMAGING REPORTS 2014. [DOI: 10.1007/s12410-013-9252-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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25
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Crooijmans HJA, Ruder TD, Zech WD, Somaini S, Scheffler K, Thali MJ, Bieri O. Cardiovascular magnetization transfer ratio imaging compared with histology: a postmortem study. J Magn Reson Imaging 2013; 40:915-9. [PMID: 24227690 DOI: 10.1002/jmri.24460] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 09/08/2013] [Indexed: 11/06/2022] Open
Abstract
Cardiovascular magnetization transfer ratio (MTR) imaging by steady state free precession is a promising imaging method to assess microstructural changes within the myocardium. Hence, MTR imaging was correlated to histological analysis. Three postmortem cases were selected based on a suspicion of myocardial infarction. MTR and T2 -weighted (T2w ) imaging was performed, followed by autopsy and histological analysis. All tissue abnormalities, identified by autopsy or histology, were retrospectively selected on visually matched MTR and T2w images, and corresponding MTR values compared with normal appearing tissue. Regions of elevated MTR (up to approximately 20%, as compared to normal tissue), appearing hypo-intense in T2w -images, revealed the presence of fibrous tissue in microscopic histological analysis. Macroscopic observation (autopsy) described scar tissue only in one case. Regions of reduced MTR (up to approximately 20%) corresponded either to (i) the presence of edema, appearing hyperintense in T2w -images and confirmed by autopsy, or to (ii) inflammatory granulocyte infiltration at a microscopic level, appearing as hypo-intense T2w -signal, but not observed by autopsy. Findings from cardiovascular MTR imaging corresponded to histology results. In contrast to T2w -imaging, MTR imaging discriminated between normal myocardium, scar tissue and regions of acute myocardial infarction in all three cases.
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Affiliation(s)
- Hendrikus J A Crooijmans
- Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland
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26
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Robson MD, Piechnik SK, Tunnicliffe EM, Neubauer S. T1 measurements in the human myocardium: the effects of magnetization transfer on the SASHA and MOLLI sequences. Magn Reson Med 2013; 70:664-70. [PMID: 23857710 DOI: 10.1002/mrm.24867] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 05/17/2013] [Accepted: 06/11/2013] [Indexed: 01/01/2023]
Abstract
PURPOSE Quantitative mapping of the native T1 of the heart using the modified look-locker inversion recovery (MOLLI) technique provides high quality diagnostic information without requiring contrast agents. Previous work has considered the effects of T2 relaxation on MOLLI T1 measurements, finding that the T1 measured by MOLLI is biased, and that Saturation-recovery single-Shot Acquisition generates a more precise T1. However, despite detailed experiments and simulation the exact relaxation times observed in vivo remain unexplained, but might be due to magnetization transfer (MT). METHODS We used an MT simulation based on the Bloch-McConnell equations to evaluate the most common MOLLI and saturation-recovery single-shot acquisition sequence variants. RESULTS For myocardial tissue we find that the T1 measured by saturation-recovery single-shot acquisition is insensitive to MT and T2, whereas MT reduces the T1 measured by MOLLI (>10%) in addition to the effects due to T2 relaxation. CONCLUSIONS The consequences of this T1 underestimation by MOLLI are relevant. Increases in the actual T1 and T2 and decreases in MT will all result in an increase in T1 measured by MOLLI. Myocardial infarction demonstrates increased native T1 and T2 and decreased MT, indicating that these biases enhance the sensitivity of MOLLI to detect this and possibly other cardiovascular disease states.
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Affiliation(s)
- Matthew D Robson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, John Radcliffe Hospital, Oxford, UK
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27
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Goldfarb JW, Hasan U, Zhao W, Han J. Magnetic resonance susceptibility weighted phase imaging for the assessment of reperfusion intramyocardial hemorrhage. Magn Reson Med 2013; 71:1210-20. [DOI: 10.1002/mrm.24747] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- James W. Goldfarb
- Department of Research and Education; Saint Francis Hospital; Roslyn New York USA
- Program in Biomedical Engineering; SUNY Stony Brook; Stony Brook New York USA
| | - Usama Hasan
- Department of Research and Education; Saint Francis Hospital; Roslyn New York USA
- New York College of Osteopathic Medicine; Old Westbury New York USA
| | - Wenguo Zhao
- Department of Research and Education; Saint Francis Hospital; Roslyn New York USA
| | - Jing Han
- Department of Research and Education; Saint Francis Hospital; Roslyn New York USA
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28
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Aissiou M, Périé D, Cheriet F, Dahdah NS, Laverdière C, Curnier D. Imaging of early modification in cardiomyopathy: the doxorubicin-induced model. Int J Cardiovasc Imaging 2013; 29:1459-76. [PMID: 23744127 DOI: 10.1007/s10554-013-0248-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 05/27/2013] [Indexed: 12/29/2022]
Abstract
Doxorubicin chemotherapy is effective and widely used to treat acute lymphoblastic leukemia. However, its effectiveness is hampered by a wide spectrum of dose-dependent cardiotoxicity including both morphological and functional changes, affecting primarily the myocardium. Non-invasive imaging techniques are used for the diagnosis and monitoring of these cardiotoxic effects. The purpose of this review is to summarize and compare the most common imaging techniques used in early detection and therapeutic monitoring of doxorubicin-induced cardiotoxicity and the suggested mechanisms of such side effects. Imaging techniques using echocardiography including conventional 2D and 3D echocardiography along with MRI sequences including Tagging, Cine, and quantitative MRI in detecting early myocardial damage are also reviewed. As there is a multitude of reported indices and imaging methods to assess particular functional alterations, we limit this review to the most relevant techniques based on their clinical application and their potential to early detection of doxorubicin-induced cardiotoxic effects.
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Affiliation(s)
- Mohamed Aissiou
- Mechanical Engineering Department, École Polytechnique de Montréal, Montreal, Canada
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29
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Coolen BF, Paulis LEM, Geelen T, Nicolay K, Strijkers GJ. Contrast-enhanced MRI of murine myocardial infarction - part II. NMR IN BIOMEDICINE 2012; 25:969-984. [PMID: 22311260 DOI: 10.1002/nbm.2767] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/07/2011] [Accepted: 11/29/2011] [Indexed: 05/31/2023]
Abstract
Mouse models are increasingly used to study the pathophysiology of myocardial infarction in vivo. In this area, MRI has become the gold standard imaging modality, because it combines high spatial and temporal resolution functional imaging with a large variety of methods to generate soft tissue contrast. In addition, (target-specific) MRI contrast agents can be employed to visualize different processes in the cascade of events following myocardial infarction. Here, the MRI sequence has a decisive role in the detection sensitivity of a contrast agent. However, a straightforward translation of clinically available protocols for human cardiac imaging to mice is not feasible, because of the small size of the mouse heart and its extremely high heart rate. This has stimulated intense research in the development of cardiac MRI protocols specifically tuned to the mouse with regard to timing parameters, acquisition strategies, and ECG- and respiratory-triggering methods to find an optimal trade-off between sensitivity, scan time, and image quality. In this review, a detailed analysis is given of the pros and cons of different mouse cardiac MR imaging methodologies and their application in contrast-enhanced MRI of myocardial infarction.
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Affiliation(s)
- Bram F Coolen
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, the Netherlands
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30
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Kumar A, Beohar N, Arumana JM, Larose E, Li D, Friedrich MG, Dharmakumar R. CMR imaging of edema in myocardial infarction using cine balanced steady-state free precession. JACC Cardiovasc Imaging 2012; 4:1265-73. [PMID: 22172783 DOI: 10.1016/j.jcmg.2011.04.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 03/09/2011] [Accepted: 04/07/2011] [Indexed: 10/14/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the capabilities of balanced steady-state free precession (bSSFP) cardiac magnetic resonance imaging as a novel cine imaging approach for characterizing myocardial edema in animals and patients after reperfused myocardial infarction. BACKGROUND Current cardiac magnetic resonance methods require 2 separate scans for assessment of myocardial edema and cardiac function. METHODS Mini-pigs (n = 13) with experimentally induced reperfused myocardial infarction and patients with reperfused ST-segment elevation myocardial infarction (n = 26) underwent cardiac magnetic resonance scans on days 2 to 4 post-reperfusion. Cine bSSFP, T2-weighted short TI inversion recovery (T2-STIR), and late gadolinium enhancement were performed at 1.5-T. Cine bSSFP and T2-STIR images were acquired with a body coil to mitigate surface coil bias. Signal, contrast, and the area of edema were compared. Additional patients (n = 10) were analyzed for the effect of microvascular obstruction on bSSFP. A receiver-operator characteristic analysis was performed to assess the accuracy of edema detection. RESULTS An area of hyperintense bSSFP signal consistent with edema was observed in the infarction zone (contrast-to-noise ratio: 37 ± 13) in all animals and correlated well with the area of late gadolinium enhancement (R = 0.83, p < 0.01). In all patients, T2-STIR and bSSFP images showed regional hyperintensity in the infarction zone. Normalized contrast-to-noise ratios were not different between T2-STIR and bSSFP. On a slice basis, the volumes of hyperintensity on T2-STIR and bSSFP images correlated well (R = 0.86, p < 0.001), and their means were not different. When compared with T2-STIR, bSSFP was positive for edema in 25 of 26 patients (96% sensitivity) and was negative in all controls (100% specificity). All patients with microvascular obstruction showed a significant reduction of signal in the subendocardial infarction zone compared with infarcted epicardial tissue without microvascular obstruction (p < 0.05). CONCLUSIONS Myocardial edema from ST-segment elevation myocardial infarction can be detected using cine bSSFP imaging with image contrast similar to T2-STIR. This new imaging approach allows evaluation of cardiac function and edema simultaneously, thereby reducing patient scan time and increasing efficiency. Further work is necessary to optimize edema contrast in bSSFP images.
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Affiliation(s)
- Andreas Kumar
- Heart and Lung Institute, Laval University, Québec City, Québec, Canada
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31
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Zhou X, Rundell V, Liu Y, Tang R, Klein R, Shah S, Zuehlsdorff S, Tsaftaris SA, Li D, Dharmakumar R. T(2) -weighted STIR imaging of myocardial edema associated with ischemia-reperfusion injury: the influence of proton density effect on image contrast. J Magn Reson Imaging 2011; 33:962-7. [PMID: 21448964 DOI: 10.1002/jmri.22456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the contribution of proton density (PD) in T(2) -STIR based edema imaging in the setting of acute myocardial infarction (AMI). MATERIALS AND METHODS Canines (n = 5), subjected to full occlusion of the left anterior descending artery for 3 hours, underwent serial magnetic resonance imaging (MRI) studies 2 hours postreperfusion (day 0) and on day 2. During each study, T(1) and T(2) maps, STIR (TE = 7.1 msec and 64 msec) and late gadolinium enhancement (LGE) images were acquired. Using T(1) and T(2) maps, relaxation and PD contributions to myocardial edema contrast (EC) in STIR images at both TEs were calculated. RESULTS Edematous territories showed significant increase in PD (20.3 ± 14.3%, P < 0.05) relative to healthy territories. The contributions of T(1) changes and T(2) or PD changes toward EC were in opposite directions. One-tailed t-test confirmed that the mean T(2) and PD-based EC at both TEs were greater than zero. EC from STIR images at TE = 7.1 msec was dominated by PD than T(2) effects (94.3 ± 11.3% vs. 17.6 ± 2.5%, P < 0.05), while at TE = 64 msec, T(2) effects were significantly greater than PD effects (90.8 ± 20.3% vs. 12.5 ± 11.9%, P < 0.05). The contribution from PD in standard STIR acquisitions (TE = 64 msec) was significantly higher than 0 (P < 0.05). CONCLUSION In addition to T(2) -weighting, edema detection in the setting of AMI with T(2) -weighted STIR imaging has a substantial contribution from PD changes, likely stemming from increased free-water content within the affected tissue. This suggests that imaging approaches that take advantage of both PD as well as T(2) effects may provide the optimal sensitivity for detecting myocardial edema.
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Affiliation(s)
- Xiangzhi Zhou
- Department of Radiology, Northwestern University, Chicago, IL, USA
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Goergen CJ, Sosnovik DE. From molecules to myofibers: multiscale imaging of the myocardium. J Cardiovasc Transl Res 2011; 4:493-503. [PMID: 21643889 DOI: 10.1007/s12265-011-9284-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 04/26/2011] [Indexed: 01/14/2023]
Abstract
Pathology in the heart can be examined at several scales, ranging from the molecular to the macroscopic. Traditionally, fluorescence-based techniques such as flow cytometry have been used to study the myocardium at the molecular, cellular, and microscopic levels. Recent advances in magnetic resonance imaging (MRI), however, have made it possible to image certain cellular and molecular events in the myocardium noninvasively in vivo. In addition, diffusion MRI has been used to image myocardial fiber architecture and microstructure in the intact heart. Diffusion MRI tractography, in particular, is providing novel insights into myocardial microsctructure in both health and disease. Recent developments have also been made in fluorescence imaging, making it possible to image fluorescent probes in the heart of small animals noninvasively in vivo. Moreover, techniques have been developed to perform in vivo fluorescence tomography of the mouse heart. These advances in MRI and fluorescence imaging allow events in the myocardium to be imaged at several scales linking molecular changes to alterations in microstructure and microstructural changes to gross function. A complete and integrated picture of pathophysiology in the myocardium is thus obtained. This multiscale approach has the potential to be of significant value not only in preclinical research but, ultimately, in the clinical arena as well.
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Affiliation(s)
- Craig J Goergen
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Zhou X, Rundell V, Liu Y, Tang R, Shah S, Zuehlsdorff S, Li D, Dharmakumar R. On the mechanisms enabling myocardial edema contrast in bSSFP-based imaging approaches. Magn Reson Med 2011; 66:187-91. [PMID: 21394764 DOI: 10.1002/mrm.22794] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 11/08/2010] [Accepted: 12/02/2010] [Indexed: 12/27/2022]
Abstract
The biophysical mechanisms influencing balanced steady-state free precession (bSSFP) based edema imaging in the setting of acute myocardial infarction are not well understood. To assess the various mechanisms that enable the detection of myocardial edema on bSSFP-based imaging approaches (cine bSSFP and T(2)-prepared bSSFP), experiments were conducted in canine models subjected to ischemia-reperfusion injury. Results showed that in addition to relaxation effects, the alteration in thermal equilibrium (M(0)) (including magnetization transfer) has a significant contribution to the image contrast between edematous and healthy myocardium. The relative signal-intensity ratios between edematous and healthy myocardium were: 1.51 ± 0.18 (cine bSSFP) and 1.58 ± 0.20 (T(2)-prepared bSSFP); the theoretically estimated relative relaxation and M(0) effects were: 1.17 ± 0.09 and 1.30 ± 0.19, respectively (cine bSSFP), and 1.49 ± 0.23 and 1.06 ± 0.07, respectively (T(2)-prepared bSSFP). There were no significant difference between cine bSSFP and T(2)-prep bSSFP relative signal-intensity ratios. However, the relative relaxation effect in cine bSSFP was significantly lower than in T(2)-prep bSSFP (P < 0.05), and the M(0) effect in cine bSSFP was significantly higher than in T(2)-prep bSSFP (P < 0.05). Hence the acquisition strategies that wish to maximize myocardial edema contrast in cine bSSFP imaging should take both relaxation and M(0) effects into account.
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Affiliation(s)
- Xiangzhi Zhou
- Department of Radiology, Northwestern University, Chicago, Illinois, USA
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Goldfarb JW, McLaughlin J, Gray CA, Han J. Cyclic CINE-balanced steady-state free precession image intensity variations: Implications for the detection of myocardial edema. J Magn Reson Imaging 2011; 33:573-81. [DOI: 10.1002/jmri.22368] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Huang S, Sosnovik DE. Molecular and Microstructural Imaging of the Myocardium. CURRENT CARDIOVASCULAR IMAGING REPORTS 2010; 3:26-33. [PMID: 20689659 DOI: 10.1007/s12410-010-9007-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The past year has witnessed ongoing progress in the field of molecular MRI of the myocardium. In addition, several novel fluorescent agents have been introduced and used to image remodeling in the injured myocardium. New techniques to image myocardial microstructure, such as diffusion spectrum MRI, have also been introduced and have tremendous potential for integration and synergy with molecular MRI. In the current review we focus on these and other advances in the field that have occurred over the past year.
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Affiliation(s)
- Shuning Huang
- CNY, Massachusetts General Hospital, 5416, 149 13th Street, Charlestown, MA 02129, USA
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