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Zhang J, Xu Y, Li W, Zhang C, Liu W, Li D, Chen Y. The Predictive Value of Myocardial Native T1 Mapping Radiomics in Dilated Cardiomyopathy: A Study in a Chinese Population. J Magn Reson Imaging 2023; 58:772-779. [PMID: 36416613 DOI: 10.1002/jmri.28527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 10/26/2022] [Accepted: 10/27/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Investigation of the factors influencing dilated cardiomyopathy (DCM) prognosis is important as it could facilitate risk stratification and guide clinical decision-making. PURPOSE To assess the prognostic value of magnetic resonance imaging (MRI) radiomics analysis of native T1 mapping in DCM. STUDY TYPE Prospective. SUBJECTS Three hundred and thirty consecutive patients with non-ischemic DCM (mean age 48.42 ± 14.20 years, 247 males). FIELD STRENGTH/SEQUENCE Balanced steady-state free precession and modified Look-Locker inversion recovery T1 mapping sequences at 3 T. ASSESSMENT Clinical characteristics, conventional MRI parameters (ventricular volumes, function, and mass), native myocardial T1, and radiomics features extracted from native T1 mapping were obtained. The study endpoint was defined as all-cause mortality or heart transplantation. Models were developed based on 1) clinical data; 2) radiomics data based on T1 mapping; 3) clinical and conventional MRI data; 4) clinical, conventional MRI, and native T1 data; and 5) clinical, conventional MRI, and radiomics T1 mapping data. Each prediction model was trained according to follow-up results with AdaBoost, random forest, and logistic regression classifiers. STATISTICAL TESTS The predictive performance was evaluated using the area under the receiver operating characteristic curve (AUC) and F1 score by 5-fold cross-validation. RESULTS During a median follow-up of 53.5 months (interquartile range, 41.6-69.5 months), 77 patients with DCM experienced all-cause mortality or heart transplantation. The random forest model based on radiomics combined with clinical and conventional MRI parameters achieved the best performance, with AUC and F1 score of 0.95 and 0.89, respectively. DATA CONCLUSION A machine-learning framework based on radiomics analysis of T1 mapping prognosis prediction in DCM. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Jian Zhang
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
- Med-X Center for Informatics, Sichuan University, Chengdu, China
| | - Yuanwei Xu
- Division of Cardiology, West China Hospital, Sichuan University, Chengdu, China
| | - Weihao Li
- Division of Cardiology, West China Hospital, Sichuan University, Chengdu, China
| | - Chao Zhang
- West China Biomedical Big Data Center, West China Hospital, Sichuan University, Chengdu, China
- Med-X Center for Informatics, Sichuan University, Chengdu, China
| | - Wentao Liu
- Fundamental Technology Center of CCB Financial Technology Co., Ltd, Shanghai, China
| | - Dong Li
- Division of Hospital Medicine, Emory School of Medicine, Atlanta, Georgia, USA
| | - Yucheng Chen
- Division of Cardiology, West China Hospital, Sichuan University, Chengdu, China
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Endo Y, Kobayashi K, Shibo H, Amanuma M, Kuhara S. Using Dictionary Matching to Improve the Accuracy of MOLLI Myocardial T1 Analysis and Measurements of Heart Rate Variability. Magn Reson Med Sci 2023; 22:389-399. [PMID: 35732413 PMCID: PMC10449558 DOI: 10.2463/mrms.tn.2022-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/29/2022] [Indexed: 11/09/2022] Open
Abstract
We analyzed modified Look-Locker inversion recovery (MOLLI) T1 measurements by applying a dictionary matching strategy and aimed to acquire T1 measurements more accurately than those acquired by the conventional three-parameter matching analysis. We particularly clarified the robustness of this method for measuring heart rate (HR) variability. A phantom experiment using a 3T MRI system was performed for various HRs. The ideal MOLLI signal corresponding to the scan parameter in the MRI experiment was simulated over a wide range of T1 values according to the dictionary. The unknown T1 values were determined by finding the simulated signals in the dictionary corresponding to the measured signals using pattern matching. The measured T1 values showed that the proposed analysis improved the accuracy of T1 measurements compared to those acquired by traditional analysis by up to 10%. In addition, the variability of measurements at several HRs was reduced by up to 100 ms.
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Affiliation(s)
- Yuta Endo
- Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University, Mitaka, Tokyo, Japan
| | - Kuninori Kobayashi
- Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University, Mitaka, Tokyo, Japan
| | - Haruna Shibo
- Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University, Mitaka, Tokyo, Japan
| | - Makoto Amanuma
- Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University, Mitaka, Tokyo, Japan
| | - Shigehide Kuhara
- Department of Medical Radiological Technology, Faculty of Health Sciences, Kyorin University, Mitaka, Tokyo, Japan
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Yu CY, Huang TY, Chung HW. Single breath-hold MR T1 mapping in the heart: Hybrid MOLLI combining saturation and inversion recovery. Magn Reson Imaging 2023; 96:85-92. [PMID: 36470451 DOI: 10.1016/j.mri.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/31/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
The native T1 values of the myocardium provide valuable information for tissue characterization and assessment of cardiomyopathies. In this study, we proposed a novel hybrid MOLLI sequence for myocardial T1 mapping. Unlike the two groups of inversion-recovery sampling of the conventional MOLLI5(3 s)3 sequence, the hybrid MOLLI sequence consisted of an inversion-recovery block followed by a saturation-recovery block. Since the second block employed a saturation pulse to spoil the longitudinal magnetization, it did not require a waiting period as MOLLI5(3 s)3 did. As a result, the hybrid MOLLI required less acquisition time leading to a practical application for patients with breath-hold difficulties. Phantom and healthy subject experiments were performed to evaluate the proposed sequence against the MOLLI5(3 s)3 sequence. The phantom study showed that the heart-rate dependency of one variant of the hybrid MOLLI sequences, hbMOLLI4, was comparable to that of MOLLI5(3 s)3. In addition, both hbMOLLI4 and MOLLI53 derived T1 values under 2% variations with simulated heart rates from 50 to 90 beats-per-minute within the range of T1 values for myocardium and blood before contrast administration. Simulation results suggested slightly reduced T1 fitting precision in hbMOLLI4 compared with MOLLI5(3 s)3, but prominently better than saturation recovery. Bland-Altman analysis on accuracy assessment revealed that hbMOLLI4 partially reduced the T1 underestimation of MOLLI5(3 s)3. In the human study, The T1 values of both methods were consistent (hbMOLLI4 vs. MOLLI5(3 s)3, slope = 1.14, R2 > 0.97), with equal reproducibility. The results supported that hybrid MOLLI produced comparable T1 mapping results in terms of accuracy, reproducibility, and heart-rate dependency, at the expense of slightly reduced precision. We concluded that the hybrid MOLLI sequence presents a competitive alternative to the MOLLI5(3 s)3 sequence when a speedy acquisition is required.
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Affiliation(s)
- Chun-Yang Yu
- Graduate Institute of Biomedical Electronics and Bioinformatics, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
| | - Teng-Yi Huang
- Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
| | - Hsiao-Wen Chung
- Graduate Institute of Biomedical Electronics and Bioinformatics, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
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Guo R, Chen Z, Amyar A, El-Rewaidy H, Assana S, Rodriguez J, Pierce P, Goddu B, Nezafat R. Improving accuracy of myocardial T 1 estimation in MyoMapNet. Magn Reson Med 2022; 88:2573-2582. [PMID: 35916305 DOI: 10.1002/mrm.29397] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/01/2022] [Accepted: 07/05/2022] [Indexed: 11/09/2022]
Abstract
PURPOSE To improve the accuracy and robustness of T1 estimation by MyoMapNet, a deep learning-based approach using 4 inversion-recovery T1 -weighted images for cardiac T1 mapping. METHODS MyoMapNet is a fully connected neural network for T1 estimation of an accelerated cardiac T1 mapping sequence, which collects 4 T1 -weighted images by a single Look-Locker inversion-recovery experiment (LL4). MyoMapNet was originally trained using in vivo data from the modified Look-Locker inversion recovery sequence, which resulted in significant bias and sensitivity to various confounders. This study sought to train MyoMapNet using signals generated from numerical simulations and phantom MR data under multiple simulated confounders. The trained model was then evaluated by phantom data scanned using new phantom vials that differed from those used for training. The performance of the new model was compared with modified Look-Locker inversion recovery sequence and saturation-recovery single-shot acquisition for measuring native and postcontrast T1 in 25 subjects. RESULTS In the phantom study, T1 values measured by LL4 with MyoMapNet were highly correlated with reference values from the spin-echo sequence. Furthermore, the estimated T1 had excellent robustness to changes in flip angle and off-resonance. Native and postcontrast myocardium T1 at 3 Tesla measured by saturation-recovery single-shot acquisition, modified Look-Locker inversion recovery sequence, and MyoMapNet were 1483 ± 46.6 ms and 791 ± 45.8 ms, 1169 ± 49.0 ms and 612 ± 36.0 ms, and 1443 ± 57.5 ms and 700 ± 57.5 ms, respectively. The corresponding extracellular volumes were 22.90% ± 3.20%, 28.88% ± 3.48%, and 30.65% ± 3.60%, respectively. CONCLUSION Training MyoMapNet with numerical simulations and phantom data will improve the estimation of myocardial T1 values and increase its robustness to confounders while also reducing the overall T1 mapping estimation time to only 4 heartbeats.
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Affiliation(s)
- Rui Guo
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Zhensen Chen
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, People's Republic of China
| | - Amine Amyar
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Hossam El-Rewaidy
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Salah Assana
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Jennifer Rodriguez
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Patrick Pierce
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Beth Goddu
- 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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Advancement of echocardiography for surveillance of iron overload cardiomyopathy: comparison to cardiac magnetic resonance imaging. J Echocardiogr 2021; 19:141-149. [PMID: 33772457 DOI: 10.1007/s12574-021-00524-x] [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: 10/21/2020] [Revised: 02/03/2021] [Accepted: 03/13/2021] [Indexed: 10/21/2022]
Abstract
The prevalence of iron overload cardiomyopathy (IOC) is increasing. Patients with transfusion-dependent anemias or conditions associated with increased iron absorption over time are at a significant risk for the development of iron-overloaded states such as IOC. Current guidelines regarding the diagnostic evaluation and follow-up of patients at risk for IOC exist, and are composed of multiple components, including such as echocardiography, genetic testing, magnetic resonance imaging of liver, and cardiac magnetic resonance imaging (CMR). While these are considered reliable for the evaluation of patients at risk for an iron-overloaded state, there is an access challenge associated with initial and serial CMR scanning in this patient population. Furthermore, there are other limiting factors, such as patient characteristics that may preclude the use of CMR as a viable diagnostic imaging modality for these patients. On the other hand, recent evidence in the literature suggests that transthoracic echocardiography, which has had significant technological advances, can equal or even outperform CMR to identify cardiac functional abnormalities such as subclinical left ventricular strain and left atrial functional abnormalities in iron overload conditions. Therefore, there is a potential role of more frequent use of echocardiography for surveillance of the development of IOC. Our purpose with this narrative review is to describe recent advances in echocardiography and propose a potential increased use of echocardiography in the surveillance of the development of IOC.
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Ando C, Yamamoto H, Shinoda N, Maeda H, Ozawa K, Ohmori Y, Yanagisawa F, Amano Y. [Effects of Heart Rate on Myocardial Native T 1 Value Acquired by 5s(3s)3s MOLLI Sequence]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2021; 77:172-181. [PMID: 33612695 DOI: 10.6009/jjrt.2021_jsrt_77.2.172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Quantitative evaluation of myocardial native T1 value by measuring modified Look-Locker inversion recovery (MOLLI) method is clinically useful and is used for follow-up of various myocardial diseases. The heart rate during the scan can vary even in the same subjects. Therefore, it is important to know the effects of the heart rate on the native T1 value of the myocardium. In this study, we evaluated the effect of the heart rate on the T1 value in the 5s (3s) 3s scheme, time control data collection period of the MOLLI method, using phantom experiments and experiments of healthy volunteers. The 5s (3s) 3s scheme of the MOLLI method is considered to have little dependence on the heart rate, but the T1 value still varied up to about 7% depending on the heart rate, and was underestimated up to 8% during low heart rate using phantom experiments.
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Affiliation(s)
- Chisato Ando
- Division of Radiological Technology, Nihon University Hospital
| | | | - Naoki Shinoda
- Division of Radiological Technology, Nihon University Hospital
| | - Hitoshi Maeda
- Division of Radiological Technology, Nihon University Hospital
| | - Kazuo Ozawa
- Division of Radiological Technology, Nihon University Hospital
| | - Yuko Ohmori
- Department of Radiology, Nihon University Hospital
| | | | - Yasuo Amano
- Department of Radiology, Nihon University Hospital
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Mau L, Kant J, Walker R, Kuchendorf CM, Schrey SD, Roessner U, Watt M. Wheat Can Access Phosphorus From Algal Biomass as Quickly and Continuously as From Mineral Fertilizer. FRONTIERS IN PLANT SCIENCE 2021; 12:631314. [PMID: 33584779 PMCID: PMC7879783 DOI: 10.3389/fpls.2021.631314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/06/2021] [Indexed: 05/05/2023]
Abstract
Algae can efficiently take up excess nutrients from waterways, making them a valuable resource potentially capable of replacing synthesized and mined fertilizers for agriculture. The capacity of algae to fertilize crops has been quantified, but it is not known how the algae-derived nutrients become available to plants. We aimed to address this question: what are the temporal dynamics of plant growth responses to algal biomass? to better propose mechanisms by which plants acquire nutrients from algal biomass and thereby study and promote those processes in future agricultural applications. Data from various sources were transformed and used to reconstruct the nutrient release from the algae Chlorella vulgaris and subsequent uptake by wheat (Triticum aestivum L.) (as reported in Schreiber et al., 2018). Plants had received 0.1x or 1x dried algae or wet algae, or zero, 0.1x or 1x mineral fertilizer calculated from agricultural practices for P application and grown to 55 days in three soils. Contents of P and other nutrients acquired from algae were as high as from mineral fertilizer, but varied based on moisture content and amount of algae applied to soils (by 55 days after sowing plants with 1x mineral fertilizer and 1x dried algae had 5.6 mg P g DWshoot; 2.2-fold more than those with 0 or 0.1x mineral fertilizer, 0.1x dried algae and wet algae, and 1x wet algae). Absolute and relative leaf area growth and estimated P uptake rates showed similar dynamics, indicating that wheat acquires P from algae quickly. A model proposes that algal fertilizer promotes wheat growth after rapid transformation in soil to inorganic nutrients. We conclude theoretically that phosphorus from algal biomass is available to wheat seedlings upon its application and is released gradually over time with minor differences related to moisture content on application. The growth and P uptake kinetics hint at nutrient forms, including N, and biomass stimulation worthy of research to further exploit algae in sustainable agriculture practices. Temporal resolved phenotype analyses in combination with a mass-balance approach is helpful for understanding resource uptake from recycled and biofertilizer sources by plants.
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Affiliation(s)
- Lisa Mau
- Institute of Bio- and Geoscience - IBG-2: Plant Science, Forschungszentrum Jülich GmbH, Jülich, Germany
- Faculty of Agriculture, University of Bonn, Bonn, Germany
| | - Josefine Kant
- Institute of Bio- and Geoscience - IBG-2: Plant Science, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Robert Walker
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Christina M. Kuchendorf
- Institute of Bio- and Geoscience - IBG-2: Plant Science, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Silvia D. Schrey
- Institute of Bio- and Geoscience - IBG-2: Plant Science, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Michelle Watt
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
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Popescu IA, Werys K, Zhang Q, Puchta H, Hann E, Lukaschuk E, Ferreira VM, Piechnik SK. Standardization of T1-mapping in cardiovascular magnetic resonance using clustered structuring for benchmarking normal ranges. Int J Cardiol 2020; 326:220-225. [PMID: 33096146 DOI: 10.1016/j.ijcard.2020.10.041] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/09/2020] [Accepted: 10/15/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Cardiovascular magnetic resonance T1-mapping is increasingly used for tissue characterization, commonly based on Modified Look-Locker Inversion recovery (MOLLI). However, there are numerous MOLLI variants with differing normal ranges. This lack of standardization presents confusion and difficulty in inter-center comparisons, hindering widespread adoption of T1-mapping. METHODS To address this, we performed a structured literature search for native left ventricular myocardial T1-mapping in healthy humans measured using MOLLI variants at 1.5 and 3 Tesla, across scanner vendors. We then used k-means clustering to structure normal MOLLI-T1 values according to magnetic field strength, and investigated correlations between common imaging parameters: repetition time (TR), echo time (TE), flip angle (FA). RESULTS We analyzed data from 2207 healthy controls in 76 independent reports. Normal MOLLI-T1 standard deviations varied by 11-fold, and dependencies on TE, TR, and FA differed between 1.5 T and 3 T, thwarting meaningful T1 standardization even within a single field strength, including the use of Z-score. However, divergent MOLLI-T1 norms may be structured using data clustering. For 1.5 T, two clusters emerged: Cluster11.5T: T1 = 958 ± 16 ms (n = 1280); Cluster21.5T: T1 = 1027 ± 19 ms (n = 386). For 3 T, three clusters emerged: Cluster13T: T1 = 1160 ± 21 ms (n = 330); Cluster23T: T1 = 1067 ± 18 ms (n = 178); Cluster33T: T1 = 1227 ± 19 ms (n = 41). We then propose the concept of an online calculator for assigning local norms to a known MOLLI-T1 cluster, allowing benchmarking against published norms. CONCLUSION Clustered structuring allows T1 standardization of widely-divergent MOLLI variants, benchmarking local norms (usually based on smaller samples) against published norms (larger samples). This may increase confidence and quality control in method implementation, facilitating wider clinical adoption of T1-mapping.
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Affiliation(s)
- Iulia A Popescu
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom.
| | - Konrad Werys
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Qiang Zhang
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Henrike Puchta
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Evan Hann
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Elena Lukaschuk
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Vanessa M Ferreira
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Stefan K Piechnik
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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Cruz G, Jaubert O, Qi H, Bustin A, Milotta G, Schneider T, Koken P, Doneva M, Botnar RM, Prieto C. 3D free-breathing cardiac magnetic resonance fingerprinting. NMR IN BIOMEDICINE 2020; 33:e4370. [PMID: 32696590 DOI: 10.1002/nbm.4370] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/04/2020] [Accepted: 06/23/2020] [Indexed: 05/15/2023]
Abstract
PURPOSE To develop a novel respiratory motion compensated three-dimensional (3D) cardiac magnetic resonance fingerprinting (cMRF) approach for whole-heart myocardial T1 and T2 mapping from a free-breathing scan. METHODS Two-dimensional (2D) cMRF has been recently proposed for simultaneous, co-registered T1 and T2 mapping from a breath-hold scan; however, coverage is limited. Here we propose a novel respiratory motion compensated 3D cMRF approach for whole-heart myocardial T1 and T2 tissue characterization from a free-breathing scan. Variable inversion recovery and T2 preparation modules are used for parametric encoding, respiratory bellows driven localized autofocus is proposed for beat-to-beat translation motion correction and a subspace regularized reconstruction is employed to accelerate the scan. The proposed 3D cMRF approach was evaluated in a standardized T1 /T2 phantom in comparison with reference spin echo values and in 10 healthy subjects in comparison with standard 2D MOLLI, SASHA and T2 -GraSE mapping techniques at 1.5 T. RESULTS 3D cMRF T1 and T2 measurements were generally in good agreement with reference spin echo values in the phantom experiments, with relative errors of 2.9% and 3.8% for T1 and T2 (T2 < 100 ms), respectively. in vivo left ventricle (LV) myocardial T1 values were 1054 ± 19 ms for MOLLI, 1146 ± 20 ms for SASHA and 1093 ± 24 ms for the proposed 3D cMRF; corresponding T2 values were 51.8 ± 1.6 ms for T2-GraSE and 44.6 ± 2.0 ms for 3D cMRF. LV coefficients of variation were 7.6 ± 1.6% for MOLLI, 12.1 ± 2.7% for SASHA and 5.8 ± 0.8% for 3D cMRF T1 , and 10.5 ± 1.4% for T2-GraSE and 11.7 ± 1.6% for 3D cMRF T2 . CONCLUSION The proposed 3D cMRF can provide whole-heart, simultaneous and co-registered T1 and T2 maps with accuracy and precision comparable to those of clinical standards in a single free-breathing scan of about 7 min.
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Affiliation(s)
- Gastão Cruz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Olivier Jaubert
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Haikun Qi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Aurélien Bustin
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Giorgia Milotta
- 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
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
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Liu X, Gómez PA, Solana AB, Wiesinger F, Menzel MI, Menze BH. Silent 3D MR sequence for quantitative and multicontrast T1 and proton density imaging. Phys Med Biol 2020; 65:185010. [PMID: 32663809 DOI: 10.1088/1361-6560/aba5e8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study aims to develop a silent, fast and 3D method for T1 and proton density (PD) mapping, while generating time series of T1-weighted (T1w) images with bias-field correction. Undersampled T1w images at different effective inversion times (TIs) were acquired using the inversion recovery prepared RUFIS sequence with an interleaved k-space trajectory. Unaliased images were reconstructed by constraining the signal evolution to a temporal subspace which was learned from the signal model. Parameter maps were obtained by fitting the data to the signal model, and bias-field correction was conducted on T1w images. Accuracy and repeatability of the method was accessed in repeated experiments with phantom and volunteers. For the phantom study, T1 values obtained by the proposed method were highly consistent with values from the gold standard method, R2 = 0.9976. Coefficients of variation (CVs) ranged from 0.09% to 0.83%. For the volunteer study, T1 values from gray and white matter regions were consistent with literature values, and peaks of gray and white matter can be clearly delineated on whole-brain T1 histograms. CVs ranged from 0.01% to 2.30%. The acoustic noise measured at the scanner isocenter was 2.6 dBA higher compared to the in-bore background. Rapid and with low acoustic noise, the proposed method is shown to produce accurate T1 and PD maps with high repeatability by reconstructing sparsely sampled T1w images at different TIs using temporal subspace. Our approach can greatly enhance patient comfort during examination and therefore increase the acceptance of the procedure.
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Affiliation(s)
- Xin Liu
- Technical University Munich, Garching, Germany. GE Global Research Europe, Munich, Germany
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11
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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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Gunasekaran S, Lee DC, Knight BP, Fan L, Collins JD, Chow K, Carr JC, Passman R, Kim D. Left Ventricular Extracellular Volume Expansion Is Not Associated with Atrial Fibrillation or Atrial Fibrillation-mediated Left Ventricular Systolic Dysfunction. Radiol Cardiothorac Imaging 2020; 2:e190096. [PMID: 32420547 PMCID: PMC7208181 DOI: 10.1148/ryct.2020190096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/26/2019] [Accepted: 10/08/2019] [Indexed: 05/02/2023]
Abstract
PURPOSE To determine whether left ventricular (LV) extracellular volume (ECV) expansion is associated with atrial fibrillation (AF) or AF-mediated LV systolic dysfunction (LVSD) while minimizing the influence of biologic and imaging methodologic confounders. MATERIALS AND METHODS This study examined the prevalence of LV ECV expansion in 137 patients with AF (mean age, 62 years ± 11 [standard deviation]; 92 male patients and 45 female patients; 83 paroxysmal and 54 persistent) who underwent preablation cardiovascular MRI. Biologic confounders were minimized by measuring the ECV fraction and excluding patients with severe LV hypertrophy, defined as wall thickness greater than 1.5 cm. Imaging confounders were minimized by using an arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping pulse sequence. Other cardiac functional parameters, including LV ejection fraction (LVEF) and left atrial end-diastolic volume indexed to body surface area, were assessed using cine cardiovascular MRI. A substudy was conducted in 32 patients with no AF (mean age, 54 years ± 16) in sinus rhythm to establish control values and convert these values between the AIR sequence and literature-based modified Look-Locker inversion recovery (MOLLI) values. RESULTS The mean ECV was not significantly different (P > .05) between patients with AF with a normal LVEF (24.5% ± 2.8; n = 107), patients with AF with LVSD (24.5% ± 2.5; n = 30), and patients with no AF (24.4% ± 3.8; n = 32), but there was a significant interaction between ECV and CHA2DS2-VASc score (P = .045). Compared with the literature data obtained from healthy control patients scanned using MOLLI, 99.3% of patients with AF had ECV below the fibrosis cutoff point (32.8% when converted from MOLLI T1 mapping to AIR T1 mapping), including a subset of patients with AF (n = 28) with low CHA2DS2-VASc score (0/1 for men/women). CONCLUSION Study results suggest that an LV ECV expansion is not associated with AF or AF-mediated LVSD. Supplemental material is available for this article. © RSNA, 2020See also the commentary by Stillman in this issue.
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Nordio G, Bustin A, Odille F, Schneider T, Henningsson M, Prieto C, Botnar RM. Faster 3D saturation-recovery based myocardial T1 mapping using a reduced number of saturation points and denoising. PLoS One 2020; 15:e0221071. [PMID: 32275668 PMCID: PMC7147792 DOI: 10.1371/journal.pone.0221071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 03/21/2020] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To accelerate the acquisition of free-breathing 3D saturation-recovery-based (SASHA) myocardial T1 mapping by acquiring fewer saturation points in combination with a post-processing 3D denoising technique to maintain high accuracy and precision. METHODS 3D SASHA T1 mapping acquires nine T1-weighted images along the saturation recovery curve, resulting in long acquisition times. In this work, we propose to accelerate conventional cardiac T1 mapping by reducing the number of saturation points. High T1 accuracy and low standard deviation (as a surrogate for precision) is maintained by applying a 3D denoising technique to the T1-weighted images prior to pixel-wise T1 fitting. The proposed approach was evaluated on a T1 phantom and 20 healthy subjects, by varying the number of T1-weighted images acquired between three and nine, both prospectively and retrospectively. Following the results from the healthy subjects, three patients with suspected cardiovascular disease were acquired using five T1-weighted images. T1 accuracy and precision was determined for all the acquisitions before and after denoising. RESULTS In the T1 phantom, no statistical difference was found in terms of accuracy and precision for the different number of T1-weighted images before or after denoising (P = 0.99 and P = 0.99 for accuracy, P = 0.64 and P = 0.42 for precision, respectively). In vivo, both prospectively and retrospectively, the precision improved considerably with the number of T1-weighted images employed before denoising (P<0.05) but was independent on the number of T1-weighted images after denoising. CONCLUSION We demonstrate the feasibility of accelerating 3D SASHA T1 mapping by reducing the number of acquired T1-weighted images in combination with an efficient 3D denoising, without affecting accuracy and precision of T1 values.
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Affiliation(s)
- Giovanna Nordio
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, England, United Kingdom
| | - Aurelien Bustin
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, England, United Kingdom
| | - Freddy Odille
- CIC-IT 1433, INSERM, Université de Lorraine and CHRU de Nancy, Nancy, France
- IADI, INSERM U1254 and Université de Lorraine, Nancy, France
| | | | - Markus Henningsson
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, England, United Kingdom
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, England, United Kingdom
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - René M. Botnar
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, England, United Kingdom
- Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile
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Gunasekaran S, Lee DC, Knight BP, Collins JD, Fan L, Trivedi A, Ragin AB, Carr JC, Passman RS, Kim D. Left ventricular extracellular volume expansion does not predict recurrence of atrial fibrillation following catheter ablation. Pacing Clin Electrophysiol 2020; 43:159-166. [PMID: 31797387 PMCID: PMC7024017 DOI: 10.1111/pace.13853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/17/2019] [Accepted: 10/28/2019] [Indexed: 01/25/2023]
Abstract
INTRODUCTION A recent study reported that diffuse left ventricular (LV) fibrosis is a predictor of atrial fibrillation (AF) recurrence following catheter ablation, by measuring postcontrast cardiac T1 (an error prone metric as per the 2017 Society for Cardiovascular Magnetic Resonance consensus statement) using an inversion-recovery pulse sequence (an error prone method in arrhythmia) in AF ablation candidates. The purpose of this study was to verify the prior study, by measuring extracellular volume (ECV) fraction (an accurate metric) using a saturation-recovery pulse sequence (accurate method in arrhythmia). METHODS AND RESULTS This study examined 100 AF patients (mean age = 62 ± 11 years, 69 males and 31 females, 67 paroxysmal [pAF] and 33 persistent [peAF]) who underwent a preablation cardiovascular magnetic resonance (CMR) exam. LV ECV and left atrial (LA) and LV functional parameters were quantified using standard analysis methods. During an average follow-up period of 457 ± 261 days with 4 ± 3 rhythm checks per patient, 72 patients maintained sinus rhythm. Between those who maintained sinus rhythm (n = 72) and those who reverted to AF (n = 28), the only clinical characteristic that was significantly different was age (60 ± 12 years vs 66 ± 9 years); for CMR metrics, neither mean LV ECV (25.1 ± 3.3% vs 24.7 ± 3.7%), native LV T1 (1093.8 ± 73.5 ms vs 1070.2 ± 115.9 ms), left ventricular ejection fraction (54.1 ± 11.2% vs 55.7 ± 7.1%), nor LA end diastolic volume/body surface area (42.4 ± 14.8 mL/m2 vs 43.4 ± 19.6 mL/m2 ) were significantly different (P ≥ .23). According to Cox regression tests, none of the clinical and imaging variables predict AF recurrence. CONCLUSION Neither LV ECV nor other CMR metrics predict recurrence of AF following catheter ablation.
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Affiliation(s)
- Suvai Gunasekaran
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States
| | - Daniel C. Lee
- Division of Cardiology, Department of Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Bradley P. Knight
- Division of Cardiology, Department of Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Jeremy D. Collins
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Lexiaozi Fan
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States
| | - Amar Trivedi
- Division of Cardiology, Department of Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Ann B. Ragin
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - James C. Carr
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Rod S. Passman
- Division of Cardiology, Department of Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Daniel Kim
- Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States
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15
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Temporal registration: a new approach to manage the incomplete recovery of the longitudinal magnetization in the Modified Look-Locker Inversion Recovery sequence (MOLLI) for T1 mapping of the heart. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2020; 33:569-580. [PMID: 31915957 DOI: 10.1007/s10334-019-00815-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/17/2019] [Accepted: 12/04/2019] [Indexed: 01/08/2023]
Abstract
PURPOSE To correct with post-processing effects of incomplete recovery of the longitudinal magnetization before a new inversion pulse in the Modified Look-Locker Inversion recovery sequence (MOLLI) sequence. THEORY AND METHODS We model such effects as a temporal shift ([Formula: see text]) of the signal of the Look-Locker block following next inversion pulses. After using the following equation [Formula: see text], a temporal registration of [Formula: see text] is applied to the signal of the affected block to adjust the sampling time of the recovery signal and correct the underlying effect on quantitative T1. To test our approach, simulations, phantoms, and five volunteers' data were used while applying different MOLLI sampling schemes at different heart rates and compared to the reference three-parameter fit. RESULTS The temporal registration of the affected signals allows to reach higher accuracy on long T1 when compared to the reference three parameters fit (10.15 vs 22.12% for T1 = 1785 ms; 8.22 vs 14.65% for T1 = 1278 ms), and lower average variation in case of rest-period deletion (62 vs 231 ms). CONCLUSION The proposed approach leads to more accurate T1 in case of incomplete recovery. It is less sensitive to parameters affecting the recovery such as the rest period or the sampling scheme; and, therefore, supports multi-center studies with different MOLLI protocols.
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16
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Shao J, Zhou Z, Nguyen KL, Finn JP, Hu P. Accurate, precise, simultaneous myocardial T1 and T2 mapping using a radial sequence with inversion recovery and T2 preparation. NMR IN BIOMEDICINE 2019; 32:e4165. [PMID: 31461194 PMCID: PMC6817390 DOI: 10.1002/nbm.4165] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 07/15/2019] [Accepted: 07/20/2019] [Indexed: 05/02/2023]
Abstract
We propose a simultaneous myocardial T1 and T2 mapping technique using a radial sequence with inversion recovery and T2 preparation, which achieves high accuracy and precision, with T1 and T2 reproducibility similar to the Modified Look-Locker Inversion recovery (MOLLI) sequence and the conventional bright blood T2 mapping technique, respectively. The sequence was developed by incorporating gold angle radial fast low angle shot (FLASH) readout combined with an inversion pulse and T2prep pulses. The extended Bloch equation simulation with slice profile correction (BLESSPC) algorithm was proposed to reconstruct T1 and T2 maps at the same time in a few seconds, while maintaining good T1 and T2 estimation accuracy. Accuracy and precision were compared among the proposed technique, MOLLI and conventional T2 mapping techniques using phantom studies, 10 healthy volunteers and three patients. In phantom studies, the proposed technique was more accurate than MOLLI (P < 0.05) while achieving similar precision (P = 0.3) in T1 estimation, and was more accurate (P < 0.05) and precise (P < 0.001) than conventional T2 mapping (two-parameter fitting) in T2 estimation. In vivo, the proposed technique achieved significantly higher T1 values (P < 0.001) and similar reproducibility (P = 0.3) compared with MOLLI, with significantly lower T2 values (P < 0.001) and similar reproducibility (P = 0.6) compared with the conventional T2 mapping technique. Thus, the proposed radial T1-T2 mapping technique allows for accurate, precise, simultaneous myocardial T1 and T2 mapping in an 11-heartbeat single breath-hold acquisition.
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Affiliation(s)
- Jiaxin Shao
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Ziwu Zhou
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Kim-Lien Nguyen
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Division of Cardiology, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - J. Paul Finn
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, CA, USA
| | - Peng Hu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, CA, USA
- Correspondence to: Peng Hu, PhD, Department of Radiological Sciences, 300 UCLA Medical Plaza Suite B119, Los Angeles, CA 90095,
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17
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Marty B, Carlier PG. MR fingerprinting for water T1 and fat fraction quantification in fat infiltrated skeletal muscles. Magn Reson Med 2019; 83:621-634. [PMID: 31502715 DOI: 10.1002/mrm.27960] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/11/2019] [Accepted: 07/31/2019] [Indexed: 12/28/2022]
Abstract
PURPOSE To develop a fast MR fingerprinting (MRF) sequence for simultaneous estimation of water T1 (T1H2O ) and fat fraction (FF) in fat infiltrated skeletal muscles. METHODS The MRF sequence for T1H2O and FF quantification (MRF T1-FF) comprises a 1400 radial spokes echo train, following nonselective inversion, with varying echo and repetition time, as well as prescribed flip angle. Undersampled frames were reconstructed at different acquisition time-points by nonuniform Fourier transform, and a bi-component model based on Bloch simulations applied to adjust the signal evolution and extract T1H2O and FF. The sequence was validated on a multi-vial phantom, in three healthy volunteers and five patients with neuromuscular diseases. We evaluated the agreement between MRF T1-FF parameters and reference values and confounding effects due to B0 and B1 inhomogeneities. RESULTS In phantom, T1H2O and FF were highly correlated with references values measured with multi-inversion time inversion recovery-stimulated echo acquisition mode and Dixon, respectively (R2 > 0.99). In vivo, T1H2O and FF determined by the MRF T1-FF sequence were also correlated with reference values (R2 = 0.98 and 0.97, respectively). The precision on T1H2O was better than 5% for muscles where FF was less than 0.4. Both T1H2O and FF values were not confounded by B0 nor B1 inhomogeneities. CONCLUSION The MRF T1-FF sequence derived T1H2O and FF values in voxels containing a mixture of water and fat protons. This method can be used to comprehend and characterize the effects of tissue water compartmentation and distribution on muscle T1 values in patients affected by chronic fat infiltration.
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Affiliation(s)
- Benjamin Marty
- NMR Laboratory, Neuromuscular Investigation Center, Institute of Myology, Paris, France.,NMR Laboratory, CEA, DRF, IBFJ, MIRCen, Paris, France
| | - Pierre G Carlier
- NMR Laboratory, Neuromuscular Investigation Center, Institute of Myology, Paris, France.,NMR Laboratory, CEA, DRF, IBFJ, MIRCen, Paris, France
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18
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Nordlund D, Xanthis C, Bidhult S, Jablonowski R, Kanski M, Kopic S, Carlsson M, Engblom H, Aletras AH, Arheden H. Measuring extracellular volume fraction by MRI: First verification of values given by clinical sequences. Magn Reson Med 2019; 83:662-672. [PMID: 31418490 PMCID: PMC6900009 DOI: 10.1002/mrm.27938] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 12/12/2022]
Abstract
Purpose To verify MR measurements of myocardial extracellular volume fraction (ECV) based on clinically applicable T1‐mapping sequences against ECV measurements by radioisotope tracer in pigs and to relate the results to those obtained in volunteers. Methods Between May 2016 and March 2017, 8 volunteers (25 ± 4 years, 3 female) and 8 pigs (4 female) underwent ECV assessment with SASHA, MOLLI5(3b)3, MOLLI5(3s)3, and MOLLI5s(3s)3s. Myocardial ECV was measured independently in pigs using a radioisotope tracer method. Results In pigs, ECV in normal myocardium was not different between radioisotope (average ± standard deviation; 19 ± 2%) and SASHA (21 ± 2%; P = 0.086). ECV was higher by MOLLI5(3b)3 (26 ± 2%), MOLLI5(3s)3 (25 ± 2%), and MOLLI5s(3s)3s (25 ± 2%) compared with SASHA or radioisotope (P ≤ 0.001 for all). ECV in volunteers was higher by MOLLI5(3b)3 (26 ± 3%) and MOLLI5(3s)3 (26 ± 3%) than by SASHA (22 ± 3%; P = 0.022 and P = 0.033). No difference was found between MOLLI5s(3s)3s (25 ± 3%) and SASHA (P = 0.225). Native T1 of blood and myocardium as well as postcontrast T1 of myocardium was consistently lower using MOLLI compared with SASHA. ECV increased over time as measured by MOLLI5(3b)3 and MOLLI5(3s)3 for pigs (0.08% and 0.07%/min; P = 0.004 and P = 0.013) and by MOLLI5s(3s)3s for volunteers (0.07%/min; P = 0.032) but did not increase as measured by SASHA. Conclusion Clinically available MOLLI and SASHA techniques can be used to accurately estimate ECV in normal myocardium where MOLLI‐sequences show minor overestimation driven by underestimation of postcontrast T1 when compared with SASHA. The timing of imaging after contrast administration affected the measurement of ECV using some variants of the MOLLI sequence.
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Affiliation(s)
- David Nordlund
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
| | - Christos Xanthis
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden.,Laboratory of Computing and Medical Informatics, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Sebastian Bidhult
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden.,Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden
| | - Robert Jablonowski
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
| | - Mikael Kanski
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
| | - Sascha Kopic
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
| | - Marcus Carlsson
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
| | - Henrik Engblom
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
| | - Anthony H Aletras
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden.,Laboratory of Computing and Medical Informatics, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Håkan Arheden
- Department of Clinical Physiology, Clinical Sciences, Lund University and Lund University Hospital, Lund, Sweden
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Cruz G, Jaubert O, Botnar RM, Prieto C. Cardiac Magnetic Resonance Fingerprinting: Technical Developments and Initial Clinical Validation. Curr Cardiol Rep 2019; 21:91. [PMID: 31352620 PMCID: PMC6661029 DOI: 10.1007/s11886-019-1181-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Magnetic resonance imaging (MRI) has enabled non-invasive myocardial tissue characterization in a wide range of cardiovascular diseases by quantifying several tissue specific parameters such as T1, T2, and T2* relaxation times. Simultaneous assessment of these parameters has recently gained interest to potentially improve diagnostic accuracy and enable further understanding of the underlying disease. However, these quantitative maps are usually acquired sequentially and are not necessarily co-registered, making multi-parametric analysis challenging. Magnetic resonance fingerprinting (MRF) has been recently introduced to unify and streamline parametric mapping into a single simultaneous, multi-parametric, fully co-registered, and efficient scan. Feasibility of cardiac MRF has been demonstrated and initial clinical validation studies are ongoing. Provide an overview of the cardiac MRF framework, recent technical developments and initial undergoing clinical validation. RECENT FINDINGS Cardiac MRF has enabled the acquisition of co-registered T1 and T2 maps in a single, efficient scan. Initial results demonstrate feasibility of cardiac MRF in healthy subjects and small patient cohorts. Current in vivo results show a small bias and comparable precision in T1 and T2 with respect to conventional clinical parametric mapping approaches. This bias may be explained by several confounding factors such as magnetization transfer and field inhomogeneities, which are currently not included in the cardiac MRF model. Initial clinical validation for cardiac MRF has demonstrated good reproducibility in healthy subjects and heart transplant patients, reduced artifacts in inflammatory cardiomyopathy patients and good differentiation between hypertrophic cardiomyopathy and healthy controls. Cardiac MRF has emerged as a novel technique for simultaneous, multi-parametric, and co-registered mapping of different tissue parameters. Initial efforts have focused on enabling T1, T2, and fat quantification; however this approach has the potential of enabling quantification of several other parameters (such as T2*, diffusion, perfusion, and flow) from a single scan. Initial results in healthy subjects and patients are promising, thus further clinical validation is now warranted.
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Affiliation(s)
- G. Cruz
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 3rd Floor, Lambeth Wing, St Thomas’ Hospital, London, SE1 7EH UK
| | - O. Jaubert
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 3rd Floor, Lambeth Wing, St Thomas’ Hospital, London, SE1 7EH UK
| | - R. M. Botnar
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 3rd Floor, Lambeth Wing, St Thomas’ Hospital, London, SE1 7EH UK
- Pontificia Universidad Católica de Chile Escuela de Ingeniería, Santiago, Chile
| | - C. Prieto
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 3rd Floor, Lambeth Wing, St Thomas’ Hospital, London, SE1 7EH UK
- Pontificia Universidad Católica de Chile Escuela de Ingeniería, Santiago, Chile
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20
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Aherne E, Chow K, Carr J. Cardiac T 1 mapping: Techniques and applications. J Magn Reson Imaging 2019; 51:1336-1356. [PMID: 31334899 DOI: 10.1002/jmri.26866] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/27/2019] [Accepted: 06/27/2019] [Indexed: 12/18/2022] Open
Abstract
A key advantage of cardiac magnetic resonance (CMR) imaging over other cardiac imaging modalities is the ability to perform detailed tissue characterization. CMR techniques continue to evolve, with advanced imaging sequences being developed to provide a reproducible, quantitative method of tissue interrogation. The T1 mapping technique, a pixel-by-pixel method of quantifying T1 relaxation time of soft tissues, has been shown to be promising for characterization of diseased myocardium in a wide variety of cardiomyopathies. In this review, we describe the basic principles and common techniques for T1 mapping and its use for native T1 , postcontrast T1 , and extracellular volume mapping. We will review a wide range of clinical applications of the technique that can be used for identification and quantification of myocardial edema, fibrosis, and infiltrative diseases with illustrative clinical examples. In addition, we will explore the current limitations of the technique and describe some areas of ongoing development. Level of Evidence: 5 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:1336-1356.
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Affiliation(s)
- Emily Aherne
- Department of Radiology, Northwestern University, Chicago, Illinois, USA
| | - Kelvin Chow
- Department of Radiology, Northwestern University, Chicago, Illinois, USA.,Cardiovascular MR R&D, Siemens Medical Solutions USA, Inc., Chicago, Illinois, USA
| | - James Carr
- Department of Radiology, Northwestern University, Chicago, Illinois, USA
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21
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Gottbrecht M, Kramer CM, Salerno M. Native T1 and Extracellular Volume Measurements by Cardiac MRI in Healthy Adults: A Meta-Analysis. Radiology 2019; 290:317-326. [PMID: 30422092 PMCID: PMC6358026 DOI: 10.1148/radiol.2018180226] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 08/30/2018] [Accepted: 09/17/2018] [Indexed: 01/06/2023]
Abstract
Purpose To summarize the literature by performing a systematic review and pooled analysis of the data, to understand the extent of variability among studies of native T1 and extracellular volume (ECV) measurements, and to identify covariates that account for heterogeneity between studies. Materials and Methods PubMed, Web of Science, and Cochrane Central were searched for native T1 and ECV measurements of the left ventricle in health adult study participants. The search terms used were "T1 mapping heart," "Native T1 heart," and "ECV heart." Summary means were generated with random-effects modeling. Heterogeneity was assessed by using the inconsistency factor (I 2). Subgroup analyses and meta-regression analyses were conducted to identify etiologic causes of heterogeneity. Results This systematic review of native T1 included 120 articles, with 5541 participants (mean age, 50 years; 51.0% men [2826 of 5541]). The pooled mean of native T1 was 976 msec (95% confidence interval [CI]: 969 msec, 983 msec) at 1.5 T and 1159 msec (95% CI: 1143 msec, 1175 msec) at 3.0 T. I 2 was 99% at both field strengths. Eighty-one articles were included in the systematic review of ECV, with 3872 participants (mean age, 52 years; 50.0% men [1936 of 3872]). The pooled mean of ECV was 25.9% at field strength of 1.5 T (95% CI: 25.5%, 26.3%) and 3.0 T (95% CI: 25.4%, 26.5%). I 2 was 94% and 90% at 1.5 and 3.0 T, respectively. Conclusion The pooled means of extracellular volume and native T1 measurements in healthy adult participants are summarized in this analysis. There was significant heterogeneity found among studies, highlighting the importance of standardized cardiac MRI protocols and the derivation of institution specific reference ranges. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Dodd and Dewey in this issue.
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Affiliation(s)
- Matthew Gottbrecht
- From the Departments of Medicine (M.G., C.M.K., M.S.), Radiology
(C.M.K., M.S.), and Biomedical Engineering (M.S.) and Cardiovascular Imaging
Center (M.G., C.M.K., M.S.), University of Virginia Health System, 1215 Lee St,
Box 800158, Charlottesville, VA 22908
| | - Christopher M. Kramer
- From the Departments of Medicine (M.G., C.M.K., M.S.), Radiology
(C.M.K., M.S.), and Biomedical Engineering (M.S.) and Cardiovascular Imaging
Center (M.G., C.M.K., M.S.), University of Virginia Health System, 1215 Lee St,
Box 800158, Charlottesville, VA 22908
| | - Michael Salerno
- From the Departments of Medicine (M.G., C.M.K., M.S.), Radiology
(C.M.K., M.S.), and Biomedical Engineering (M.S.) and Cardiovascular Imaging
Center (M.G., C.M.K., M.S.), University of Virginia Health System, 1215 Lee St,
Box 800158, Charlottesville, VA 22908
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Liu Y, Hamilton J, Rajagopalan S, Seiberlich N. Cardiac Magnetic Resonance Fingerprinting: Technical Overview and Initial Results. JACC Cardiovasc Imaging 2018; 11:1837-1853. [PMID: 30522686 PMCID: PMC6394856 DOI: 10.1016/j.jcmg.2018.08.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 01/03/2023]
Abstract
Cardiovascular magnetic resonance is a versatile tool that enables noninvasive characterization of cardiac tissue structure and function. Parametric mapping techniques have allowed unparalleled differentiation of pathophysiological differences in the myocardium such as the delineation of myocardial fibrosis, hemorrhage, and edema. These methods are increasingly used as part of a tool kit to characterize disease states such as cardiomyopathies and coronary artery disease more accurately. Currently conventional mapping techniques require separate acquisitions for T1 and T2 mapping, the values of which may depend on specifics of the magnetic resonance imaging system hardware, pulse sequence implementation, and physiological variables including blood pressure and heart rate. The cardiac magnetic resonance fingerprinting (cMRF) technique has recently been introduced for simultaneous and reproducible measurement of T1 and T2 maps in a single scan. The potential for this technique to provide consistent tissue property values independent of variables including scanner, pulse sequence, and physiology could allow an unbiased framework for the assessment of intrinsic properties of cardiac tissue including structure, perfusion, and parameters such as extracellular volume without the administration of exogenous contrast agents. This review seeks to introduce the basics of the cMRF technique, including pulse sequence design, dictionary generation, and pattern matching. The potential applications of cMRF in assessing diseases such as nonischemic cardiomyopathy are also briefly discussed, and ongoing areas of research are described.
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Affiliation(s)
- Yuchi Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Jesse Hamilton
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Sanjay Rajagopalan
- Department of Cardiovascular Medicine, University Hospitals, Harrington Heart and Vascular Institute, Cleveland Medical Center and Case Western Reserve School of Medicine, Cleveland, Ohio
| | - Nicole Seiberlich
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio; Department of Cardiovascular Medicine, University Hospitals, Harrington Heart and Vascular Institute, Cleveland Medical Center and Case Western Reserve School of Medicine, Cleveland, Ohio; Department of Radiology, Case Western Reserve University, Cleveland, Ohio.
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23
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3D SASHA myocardial T1 mapping with high accuracy and improved precision. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2018; 32:281-289. [PMID: 30191345 PMCID: PMC6424941 DOI: 10.1007/s10334-018-0703-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 08/23/2018] [Accepted: 08/29/2018] [Indexed: 12/28/2022]
Abstract
Purpose To improve the precision of a free-breathing 3D saturation-recovery-based myocardial T1 mapping sequence using a post-processing 3D denoising technique. Methods A T1 phantom and 15 healthy subjects were scanned on a 1.5 T MRI scanner using 3D saturation-recovery single-shot acquisition (SASHA) for myocardial T1 mapping. A 3D denoising technique was applied to the native T1-weighted images before pixel-wise T1 fitting. The denoising technique imposes edge-preserving regularity and exploits the co-occurrence of 3D spatial gradients in the native T1-weighted images by incorporating a multi-contrast Beltrami regularization. Additionally, 2D modified Look-Locker inversion recovery (MOLLI) acquisitions were performed for comparison purposes. Accuracy and precision were measured in the myocardial septum of 2D MOLLI and 3D SASHA T1 maps and then compared. Furthermore, the accuracy and precision of the proposed approach were evaluated in a standardized phantom in comparison to an inversion-recovery spin-echo sequence (IRSE). Results For the phantom study, Bland–Altman plots showed good agreement in terms of accuracy between IRSE and 3D SASHA, both on non-denoised and denoised T1 maps (mean difference −1.4 ± 18.9 ms and −4.4 ± 21.2 ms, respectively), while 2D MOLLI generally underestimated the T1 values (69.4 ± 48.4 ms). For the in vivo study, there was a statistical difference between the precision measured on 2D MOLLI and on non-denoised 3D SASHA T1 maps (P = 0.005), while there was no statistical difference after denoising (P = 0.95). Conclusion The precision of 3D SASHA myocardial T1 mapping was substantially improved using a 3D Beltrami regularization based denoising technique and was similar to that of 2D MOLLI T1 mapping, while preserving the higher accuracy and whole-heart coverage of 3D SASHA. Electronic supplementary material The online version of this article (10.1007/s10334-018-0703-y) contains supplementary material, which is available to authorized users.
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Shao XN, Sun YJ, Xiao KT, Zhang Y, Zhang WB, Kou ZF, Cheng JL. Texture analysis of magnetic resonance T1 mapping with dilated cardiomyopathy: A machine learning approach. Medicine (Baltimore) 2018; 97:e12246. [PMID: 30212958 PMCID: PMC6156048 DOI: 10.1097/md.0000000000012246] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/10/2018] [Indexed: 11/25/2022] Open
Abstract
The diagnosis of dilated cardiomyopathy (DCM) remains a challenge in clinical radiology. This study aimed to investigate whether texture analysis (TA) parameters on magnetic resonance T1 mapping can be helpful for the diagnosis of DCM.A total of 50 DCM cases were retrospectively screened and 24 healthy controls were prospectively recruited between March 2015 and July 2017. T1 maps were acquired using the Modified Look-Locker Inversion Recovery (MOLLI) sequence at a 3.0 T MR scanner. The endocardium and epicardium were drawn on the short-axis slices of the T1 maps by an experienced radiologist. Twelve histogram parameters and 5 gray-level co-occurrence matrix (GLCM) features were extracted during the TA. Differences in texture features between DCM patients and healthy controls were evaluated by t test. Support vector machine (SVM) was used to calculate the diagnostic accuracy of those texture parameters.Most histogram features were higher in the DCM group when compared to healthy controls, and 9 of these had significant differences between the DCM group and healthy controls. In terms of GLCM features, energy, correlation, and homogeneity were higher in the DCM group, when compared with healthy controls. In addition, entropy and contrast were lower in the DCM group. Moreover, entropy, contrast, and homogeneity had significant differences between these 2 groups. The diagnostic accuracy when using the SVM classifier with all these histogram and GLCM features was 0.85 ± 0.07.A computer-based TA and machine learning approach of T1 mapping can provide an objective tool for the diagnosis of DCM.
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Affiliation(s)
- Xiao-Ning Shao
- Department of Magnetic Resonance, The First Affiliated Hospital of Zhengzhou University, Zhengzhou
| | - Ying-Jie Sun
- Department of Radiology, The Second Affiliated Hospital of Luohe Medical College, Luohe
| | - Kun-Tao Xiao
- School of Mathematical Sciences, Zhejiang University, Hangzhou, China
| | - Yong Zhang
- Department of Magnetic Resonance, The First Affiliated Hospital of Zhengzhou University, Zhengzhou
| | - Wen-Bo Zhang
- Department of Magnetic Resonance, The First Affiliated Hospital of Zhengzhou University, Zhengzhou
| | - Zhi-Feng Kou
- Department of Biomedical Engineering, Wayne State University, Detroit, MI
| | - Jing-Liang Cheng
- Department of Magnetic Resonance, The First Affiliated Hospital of Zhengzhou University, Zhengzhou
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25
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Chen Y, Lo WC, Hamilton JI, Barkauskas K, Saybasili H, Wright KL, Batesole J, Griswold MA, Gulani V, Seiberlich N. Single breath-hold 3D cardiac T 1 mapping using through-time spiral GRAPPA. NMR IN BIOMEDICINE 2018; 31:e3923. [PMID: 29637637 PMCID: PMC5980781 DOI: 10.1002/nbm.3923] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 02/26/2018] [Accepted: 02/27/2018] [Indexed: 06/08/2023]
Abstract
The quantification of cardiac T1 relaxation time holds great potential for the detection of various cardiac diseases. However, as a result of both cardiac and respiratory motion, only one two-dimensional T1 map can be acquired in one breath-hold with most current techniques, which limits its application for whole heart evaluation in routine clinical practice. In this study, an electrocardiogram (ECG)-triggered three-dimensional Look-Locker method was developed for cardiac T1 measurement. Fast three-dimensional data acquisition was achieved with a spoiled gradient-echo sequence in combination with a stack-of-spirals trajectory and through-time non-Cartesian generalized autocalibrating partially parallel acquisition (GRAPPA) acceleration. The effects of different magnetic resonance parameters on T1 quantification with the proposed technique were first examined by simulating data acquisition and T1 map reconstruction using Bloch equation simulations. Accuracy was evaluated in studies with both phantoms and healthy subjects. These results showed that there was close agreement between the proposed technique and the reference method for a large range of T1 values in phantom experiments. In vivo studies further demonstrated that rapid cardiac T1 mapping for 12 three-dimensional partitions (spatial resolution, 2 × 2 × 8 mm3 ) could be achieved in a single breath-hold of ~12 s. The mean T1 values of myocardial tissue and blood obtained from normal volunteers at 3 T were 1311 ± 66 and 1890 ± 159 ms, respectively. In conclusion, a three-dimensional T1 mapping technique was developed using a non-Cartesian parallel imaging method, which enables fast and accurate T1 mapping of cardiac tissues in a single short breath-hold.
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Affiliation(s)
- Yong Chen
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wei-Ching Lo
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jesse I Hamilton
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Kestutis Barkauskas
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | | | - Katherine L Wright
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Joshua Batesole
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mark A Griswold
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Vikas Gulani
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Nicole Seiberlich
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
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26
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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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27
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Aus dem Siepen F, Baumgärtner C, Müller-Henessen M, André F, Messroghli D, Ochs M, Riffel J, Giannitsis E, Katus HA, Friedrich MG, Buss SJ. Variability of cardiovascular magnetic resonance (CMR) T1 mapping parameters in healthy volunteers during long-term follow-up. Open Heart 2018. [PMID: 29531760 PMCID: PMC5845426 DOI: 10.1136/openhrt-2017-000717] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Background Myocardial T1 and extracellular volume (ECV) derived from cardiovascular MRIs are more and more widely accepted as important markers for diagnosis, risk prediction and monitoring of cardiac disease. Yet data regarding long-term stability of myocardial T1 mapping are lacking. The aim of this study was to investigate the long-term stability of native and postcontrast T1 mapping values in healthy volunteers. Methods 18 strictly selected healthy volunteers (52±10 years, 12 men) were studied on a Philips Achieva 1.5 Tesla scanner. T1 relaxation times were measured before and 15 min after a bolus contrast injection of gadolinium diethylenetriamine penta-acetic acid (DTPA) (0.2 mmol/kg) using a single-breath-hold modified Look-Locker inversion recovery 3(3)3(3)5 sequence. ECV was calculated using native and postcontrast T1 times of myocardium and blood correcting for blood haematocrit. Exams were repeated 3.6±0.5 years later under the same conditions and using the same scan protocols. Results Cardiac biomarkers (high-sensitivity troponin T and N terminal pro-brain natriuretic peptide) remained unchanged, as well as left ventricular mass, and global and longitudinal function. No significant change occurred regarding native T1 times (1017±24 ms vs 1015±21 ms; P=0.6), postcontrast T1 times (426±38 ms vs 413±20 ms; P=0.13) or ECV (22%±2% vs 23%±2%; P=0.3). Native T1 time and ECV appeared to be better reproducible than postcontrast T1, resulting in lower coefficients of variation (ECV: 3.5%, native T1: 1.3%, postcontrast T1: 6.4%) and smaller limits of agreement (ECV: 2%/−2%, native T1: 39 ms/−35 ms, postcontrast T1: 85 ms/−59 ms). Conclusions During long-term follow-up, native T1 and ECV values are very robust markers, whereas postcontrast T1 results appear less stable.
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Affiliation(s)
- Fabian Aus dem Siepen
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Christian Baumgärtner
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias Müller-Henessen
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Florian André
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Daniel Messroghli
- Department of Internal Medicine - Cardiology, Deutsches Herzzentrum Berlin and Charité, University Medicine Berlin, Berlin, Germany
| | - Marco Ochs
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Johannes Riffel
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Evangelos Giannitsis
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Matthias G Friedrich
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sebastian J Buss
- Department of Cardiology, Angiology and Respiratory Medicine, University Hospital Heidelberg, Heidelberg, Germany
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28
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Cardiac magnetic resonance T1 and extracellular volume mapping with motion correction and co-registration based on fast elastic image registration. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 31:115-129. [PMID: 29270904 PMCID: PMC5813095 DOI: 10.1007/s10334-017-0668-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 11/05/2017] [Accepted: 11/25/2017] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Our aim was to investigate the technical feasibility of a novel motion compensation method for cardiac magntic resonance (MR) T1 and extracellular volume fraction (ECV) mapping. MATERIALS AND METHODS Native and post-contrast T1 maps were obtained using modified look-locker inversion recovery (MOLLI) pulse sequences with acquisition scheme defined in seconds. A nonrigid, nonparametric, fast elastic registration method was applied to generate motion-corrected T1 maps and subsequently ECV maps. Qualitative rating was performed based on T1 fitting-error maps and overlay images. Local deformation vector fields were produced for quantitative assessment. Intra- and inter-observer reproducibility were compared with and without motion compensation. RESULTS Eighty-two T1 and 39 ECV maps were obtained in 21 patients with diverse myocardial diseases. Approximately 60% demonstrated clear quality improvement after motion correction for T1 mapping, particularly for the poor-rating cases (23% before vs 2% after). Approximately 67% showed further improvement with co-registration in ECV mapping. Although T1 and ECV values were not clinically significantly different before and after motion compensation, there was improved intra- and inter-observer reproducibility after motion compensation. CONCLUSIONS Automated motion correction and co-registration improved the qualitative assessment and reproducibility of cardiac MR T1 and ECV measurements, allowing for more reliable ECV mapping.
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29
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Piechnik SK, Jerosch-Herold M. Myocardial T1 mapping and extracellular volume quantification: an overview of technical and biological confounders. Int J Cardiovasc Imaging 2017; 34:3-14. [PMID: 28849419 PMCID: PMC5851695 DOI: 10.1007/s10554-017-1235-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 08/10/2017] [Indexed: 11/24/2022]
Abstract
Novel tissue biomarkers based on the spin–lattice relaxation time T1, a fundamental property in the theory of magnetic resonance physics, have emerged as a new approach for myocardial tissue characterization with many validated clinical applications. This article is intended as an overview of the physical and physiological mechanisms underlying the interpretation and the accuracy of any practical measurement of T1, or derived biomarkers such as extravascular volume fraction, and also includes a discussion of potential pitfalls. Numerous caveats und knowledge gaps related to the precise interpretation of T1-based biomarkers remain, which are being addressed incrementally through ongoing research. Equally important, further careful standardization will pave the way for a wider clinical translation of these novel T1-based biomarkers of tissue remodeling, which have been well validated for their sensitivity to pathophysiological changes, though for the most part in single-center studies.
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Affiliation(s)
- Stefan K Piechnik
- Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX39DU, UK
| | - Michael Jerosch-Herold
- Brigham and Women's Hospital, and Harvard Medical School, 15 Francis Street, Boston, MA, 02115, USA.
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30
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Marty B, Coppa B, Carlier PG. Fast, precise, and accurate myocardial T 1 mapping using a radial MOLLI sequence with FLASH readout. Magn Reson Med 2017; 79:1387-1398. [PMID: 28671304 DOI: 10.1002/mrm.26795] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/24/2017] [Accepted: 05/25/2017] [Indexed: 12/21/2022]
Abstract
PURPOSE Quantitative cardiac MRI, and more particularly T1 mapping, has become a most important modality to characterize myocardial tissue. In this work, the value of a radial variant of the conventional modified Look-Locker inversion recovery sequence (raMOLLI) is demonstrated. METHODS The raMOLLI acquisition scheme consisted of five radial echo trains of 80 spokes acquired using either a fast low-angle shot (FLASH) or a true fast imaging with steady-state-precession (TrueFISP) readout at different time points after a single magnetization inversion. View sharing combined with a compressed sensing algorithm allowed the reconstruction of 50 images along the T1 relaxation recovery curve, to which a dictionary-fitting approach was applied to estimate T1 . The sequence was validated on a nine-vial phantom, on 19 healthy subjects, and one patient suffering from dilated cardiomyopathy. RESULTS The raMOLLI sequence allowed a significant decrease of myocardial T1 map acquisition time down to five heartbeats, while exhibiting a higher degree of accuracy and a comparable precision on T1 value estimation than the conventional modified Look-Locker inversion recovery sequence. The FLASH readout demonstrated a better robustness to B0 inhomogeneities than TrueFISP, and was therefore preferred for in vivo acquisitions. CONCLUSIONS This sequence represents a good candidate for ultrafast acquisition of myocardial T1 maps. Magn Reson Med 79:1387-1398, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- B Marty
- Institute of Myology, NMR Laboratory, Paris, France.,CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France
| | - B Coppa
- Institute of Myology, NMR Laboratory, Paris, France.,CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France
| | - P G Carlier
- Institute of Myology, NMR Laboratory, Paris, France.,CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France
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31
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Towards accurate and precise T 1 and extracellular volume mapping in the myocardium: a guide to current pitfalls and their solutions. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 31:143-163. [PMID: 28608328 PMCID: PMC5813078 DOI: 10.1007/s10334-017-0631-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/05/2017] [Accepted: 05/24/2017] [Indexed: 01/27/2023]
Abstract
Mapping of the longitudinal relaxation time (T1) and extracellular volume (ECV) offers a means of identifying pathological changes in myocardial tissue, including diffuse changes that may be invisible to existing T1-weighted methods. This technique has recently shown strong clinical utility for pathologies such as Anderson-Fabry disease and amyloidosis and has generated clinical interest as a possible means of detecting small changes in diffuse fibrosis; however, scatter in T1 and ECV estimates offers challenges for detecting these changes, and bias limits comparisons between sites and vendors. There are several technical and physiological pitfalls that influence the accuracy (bias) and precision (repeatability) of T1 and ECV mapping methods. The goal of this review is to describe the most significant of these, and detail current solutions, in order to aid scientists and clinicians to maximise the utility of T1 mapping in their clinical or research setting. A detailed summary of technical and physiological factors, issues relating to contrast agents, and specific disease-related issues is provided, along with some considerations on the future directions of the field.
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32
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Shao J, Liu D, Sung K, Nguyen KL, Hu P. Accuracy, precision, and reproducibility of myocardial T1 mapping: A comparison of four T1 estimation algorithms for modified look-locker inversion recovery (MOLLI). Magn Reson Med 2016; 78:1746-1756. [PMID: 27917529 DOI: 10.1002/mrm.26565] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 11/01/2016] [Accepted: 11/06/2016] [Indexed: 01/07/2023]
Abstract
PURPOSE To compare the accuracy and precision of four different T1 estimation algorithms for modified Look-Locker inversion recovery (MOLLI). METHODS Four T1 estimation algorithms, including the original fit, inversion group (IG) fit, instantaneous signal loss simulation (InSiL), and Bloch equation simulation with slice profile correction (BLESSPC) were studied. T1 estimation accuracy, precision, reproducibility, and sensitivity to heart rate (HR), flip angle (FA), and acquisition scheme (AcS) variations were compared in simulation, phantom, and volunteer studies. RESULTS T1 estimation accuracy of IG (-2.4% ± 3.9%) and original fit (-3.2% ± 1.4%) were worse than BLESSPC (0.2% ± 1.5%) and InSiL (-0.7% ± 2.1%). The original fit had the best precision for T1 from 409-1884 ms for the same FA (0.67% ± 0.16% versus 0.90% ± 0.23% using IG, 0.78% ± 0.11% using InSiL, 0.77% ± 0.12% using BLESSPC). BLESSPC generated the most consistent in vivo T1 values over different FAs and AcS, and the T1 estimation reproducibility was similar (P > 0.3) among the four methods when FA = 35°. When using FA = 50°, the reproducibility was significantly improved only when using BLESSPC (1.6% ± 0.9 versus 2.6% ± 1.9%, P < 0.05). CONCLUSION BLESSPC has superior accuracy and is the least sensitive to FA, HR, and AcS variations. T1 estimation using BLESSPC and FA = 50° is superior to conventional MOLLI with FA = 35° in accuracy and precision. Further clinical studies in varying pathological conditions are warranted to confirm our findings. Magn Reson Med 78:1746-1756, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Jiaxin Shao
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Dapeng Liu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Kyunghyun Sung
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Kim-Lien Nguyen
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Division of Cardiology, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Peng Hu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA.,Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, California, USA
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33
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Vassiliou VS, Heng EL, Gatehouse PD, Donovan J, Raphael CE, Giri S, Babu-Narayan SV, Gatzoulis MA, Pennell DJ, Prasad SK, Firmin DN. Magnetic resonance imaging phantoms for quality-control of myocardial T1 and ECV mapping: specific formulation, long-term stability and variation with heart rate and temperature. J Cardiovasc Magn Reson 2016; 18:62. [PMID: 27659737 PMCID: PMC5034463 DOI: 10.1186/s12968-016-0275-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/23/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Magnetic resonance imaging (MRI) phantoms are routinely used for quality assurance in MRI centres; however their long term stability for verification of myocardial T1/ extracellular volume fraction (ECV) mapping has never been investigated. METHODS Nickel-chloride agarose gel phantoms were formulated in a reproducible laboratory procedure to mimic blood and myocardial T1 and T2 values, native and late after Gadolinium administration as used in T1/ECV mapping. The phantoms were imaged weekly with an 11 heart beat MOLLI sequence for T1 and long TR spin-echo sequences for T2, in a carefully controlled reproducible manner for 12 months. RESULTS There were only small relative changes seen in all the native and post gadolinium T1 values (up to 9.0 % maximal relative change in T1 values) or phantom ECV (up to 8.3 % maximal relative change of ECV, up to 2.2 % maximal absolute change in ECV) during this period. All native and post gadolinium T2 values remained stable over time with <2 % change. Temperature sensitivity testing showed MOLLI T1 values in the long T1 phantoms increasing by 23.9 ms per degree increase and short T1 phantoms increasing by 0.3 ms per degree increase. There was a small absolute increase in ECV of 0.069 % (~0.22 % relative increase in ECV) per degree increase. Variation in heart rate testing showed a 0.13 % absolute increase in ECV (~0.45 % relative increase in ECV) per 10 heart rate increase. CONCLUSIONS These are the first phantoms reported in the literature modeling T1 and T2 values for blood and myocardium specifically for the T1mapping/ECV mapping application, with stability tested rigorously over a 12 month period. This work has significant implications for the utility of such phantoms in improving the accuracy of serial scans for myocardial tissue characterisation by T1 mapping methods and in multicentre work.
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Affiliation(s)
- Vassilios S. Vassiliou
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Ee Ling Heng
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Peter D. Gatehouse
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Jacqueline Donovan
- Department of Biochemistry, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Claire E. Raphael
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | | | - Sonya V. Babu-Narayan
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Michael A. Gatzoulis
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Dudley J. Pennell
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Sanjay K. Prasad
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - David N. Firmin
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Imperial College, National Heart and Lung Institute, London, UK
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Captur G, Gatehouse P, Keenan KE, Heslinga FG, Bruehl R, Prothmann M, Graves MJ, Eames RJ, Torlasco C, Benedetti G, Donovan J, Ittermann B, Boubertakh R, Bathgate A, Royet C, Pang W, Nezafat R, Salerno M, Kellman P, Moon JC. A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance-the T 1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program. J Cardiovasc Magn Reson 2016; 18:58. [PMID: 27660042 PMCID: PMC5034411 DOI: 10.1186/s12968-016-0280-z] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 09/02/2016] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND T1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T1 mapping to global clinical care, we developed a phantom-based quality assurance (QA) system for verification of measurement stability over time at individual sites, with further aims of generalization of results across sites, vendor systems, software versions and imaging sequences. We thus created T1MES: The T1 Mapping and ECV Standardization Program. METHODS A design collaboration consisting of a specialist MRI small-medium enterprise, clinicians, physicists and national metrology institutes was formed. A phantom was designed covering clinically relevant ranges of T1 and T2 in blood and myocardium, pre and post-contrast, for 1.5 T and 3 T. Reproducible mass manufacture was established. The device received regulatory clearance by the Food and Drug Administration (FDA) and Conformité Européene (CE) marking. RESULTS The T1MES phantom is an agarose gel-based phantom using nickel chloride as the paramagnetic relaxation modifier. It was reproducibly specified and mass-produced with a rigorously repeatable process. Each phantom contains nine differently-doped agarose gel tubes embedded in a gel/beads matrix. Phantoms were free of air bubbles and susceptibility artifacts at both field strengths and T1 maps were free from off-resonance artifacts. The incorporation of high-density polyethylene beads in the main gel fill was effective at flattening the B 1 field. T1 and T2 values measured in T1MES showed coefficients of variation of 1 % or less between repeat scans indicating good short-term reproducibility. Temperature dependency experiments confirmed that over the range 15-30 °C the short-T1 tubes were more stable with temperature than the long-T1 tubes. A batch of 69 phantoms was mass-produced with random sampling of ten of these showing coefficients of variations for T1 of 0.64 ± 0.45 % and 0.49 ± 0.34 % at 1.5 T and 3 T respectively. CONCLUSION The T1MES program has developed a T1 mapping phantom to CE/FDA manufacturing standards. An initial 69 phantoms with a multi-vendor user manual are now being scanned fortnightly in centers worldwide. Future results will explore T1 mapping sequences, platform performance, stability and the potential for standardization.
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Affiliation(s)
- Gabriella Captur
- UCL Biological Mass Spectrometry Laboratory, Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London, UK
- NIHR University College London Hospitals Biomedical Research Center, Maple House Suite, Tottenham Court Road, London, W1T 7DN UK
- Barts Heart Center, St Bartholomew’s Hospital, West Smithfield, London, EC1A 7BE UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
| | - Peter Gatehouse
- CMR Department, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Kathryn E. Keenan
- National Institutes of Standards and Technology (NIST), Boulder, MS 818.03, 325 Broadway, Boulder, CO 80305-3337 USA
| | - Friso G. Heslinga
- Biomagnetics Group, School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 Australia
- NeuroImaging group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
| | - Ruediger Bruehl
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2 – 12, D-10587, Berlin, Germany
| | - Marcel Prothmann
- Cardiology, Charité, Medical Faculty of Humboldt-University Berlin ECRC and HELIOS Clinics, Berlin, Germany
| | - Martin J. Graves
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Richard J. Eames
- Department of Physics, Imperial College London, Prince Consort Rd, London, SW7 2BB UK
| | - Camilla Torlasco
- University of Milan-Bicocca, Piazza dell’Ateneo Nuovo 1, 20100 Milan, Italy
| | | | - Jacqueline Donovan
- Department of Clinical Biochemistry, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2 – 12, D-10587, Berlin, Germany
| | - Redha Boubertakh
- Cardiovascular Biomedical Research Unit, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Andrew Bathgate
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Celine Royet
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Wenjie Pang
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division) Beth Israel Deaconess Medical Center, Harvard Medical School, Cardiology East Campus, Room E/SH455, 330 Brookline Ave, Boston, MA 02215 USA
| | - Michael Salerno
- University of Virginia Health System, 1215 Lee St, PO Box 800158, Charlottesville, VA 22908 USA
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, 10 Center Drive, Building 10, Room B1D416, MSC1061, Bethesda, MD 20892-1061 USA
| | - James C. Moon
- NIHR University College London Hospitals Biomedical Research Center, Maple House Suite, Tottenham Court Road, London, W1T 7DN UK
- Barts Heart Center, St Bartholomew’s Hospital, West Smithfield, London, EC1A 7BE UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
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Blaszczyk E, Töpper A, Schmacht L, Wanke F, Greiser A, Schulz-Menger J, von Knobelsdorff-Brenkenhoff F. Influence of spatial resolution and contrast agent dosage on myocardial T1 relaxation times. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 30:85-91. [PMID: 27544271 DOI: 10.1007/s10334-016-0581-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Our aim was to study the influence of small variations in spatial resolution and contrast agent dosage on myocardial T1 relaxation time. MATERIALS AND METHODS Twenty-nine healthy volunteers underwent cardiovascular magnetic resonance at 3T twice, including a modified look-locker inversion recovery (MOLLI) technique-3(3)3(3)5-for T1 mapping. Native T1 was assessed in three spatial resolutions (voxel size 1.4 × 1.4 × 6, 1.6 × 1.6 × 6, 1.7 × 1.7 × 6 mm3), and postcontrast T1 after 0.1 and 0.2 mmol/kg gadobutrol. Partition coefficient was calculated based on myocardial and blood T1. T1 analysis was done per segment, per slice, and for the whole heart. RESULTS Native T1 values did not differ with varying spatial resolution per segment (p = 0.116-0.980), per slice (basal: p = 0.772; middle: p = 0.639; apex: p = 0.276), and globally (p = 0.191). Postcontrast T1 values were significantly lower with higher contrast agent dosage (p < 0.001). The global partition coefficient was 0.43 ± 0.3 for 0.2 and 0.1 mmol gadobutrol (p = 0.079). CONCLUSION Related to the tested MOLLI technique at 3T, very small variations in spatial resolution (voxel sizes between 1.4 × 1.4 × 6 and 1.7 × 1.7 × 6 mm3) remained without effect on the native T1 relaxation times. Postcontrast T1 values were naturally shorter with higher contrast agent dosage while the partition coefficient remained constant. Further studies are necessary to test whether these conclusions hold true for larger matrix sizes and in larger cohorts.
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Affiliation(s)
- Edyta Blaszczyk
- Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.,Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany
| | - Agnieszka Töpper
- Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.,Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany
| | - Luisa Schmacht
- Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.,Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany
| | - Felix Wanke
- Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.,Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany
| | | | - Jeanette Schulz-Menger
- Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.,Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany
| | - Florian von Knobelsdorff-Brenkenhoff
- Working Group Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A Joint Cooperation Between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Lindenberger Weg 80, 13125, Berlin, Germany. .,Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany.
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Bidhult S, Kantasis G, Aletras AH, Arheden H, Heiberg E, Hedström E. Validation of T1 and T2 algorithms for quantitative MRI: performance by a vendor-independent software. BMC Med Imaging 2016; 16:46. [PMID: 27501697 PMCID: PMC4977731 DOI: 10.1186/s12880-016-0148-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 07/28/2016] [Indexed: 11/26/2022] Open
Abstract
Background Determination of the relaxation time constants T1 and T2 with quantitative magnetic resonance imaging is increasingly used for both research and clinical practice. Recently, groups have been formed within the Society of Cardiovascular Magnetic Resonance to address issues with relaxometry. However, so far they have avoided specific recommendations on methodology due to lack of consensus and current evolving research. Standardised widely available software may simplify this process. The purpose of the current study was to develop and validate vendor-independent T1 and T2 mapping modules and implement those in the versatile and widespread software Segment, freely available for research and FDA approved for clinical applications. Results The T1 and T2 mapping modules were developed and validated in phantoms at 1.5 T and 3 T with reference standard values calculated from reference pulse sequences using the Nelder-Mead Simplex optimisation method. The proposed modules support current commonly available MRI pulse sequences and both 2- and 3-parameter curve fitting. Images acquired in patients using three major vendors showed vendor-independence. Bias and variability showed high agreement with T1 and T2 reference standards for T1 (range 214–1752 ms) and T2 (range 45–338 ms), respectively. Conclusions The developed and validated T1 and T2 mapping and quantification modules generated relaxation maps from current commonly used MRI sequences and multiple signal models. Patient applications showed usability for three major vendors.
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Affiliation(s)
- Sebastian Bidhult
- Department of Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden.,Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden
| | - George Kantasis
- Department of Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden.,Laboratory of Medical Informatics, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Anthony H Aletras
- Department of Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden.,Laboratory of Medical Informatics, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Håkan Arheden
- Department of Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden
| | - Einar Heiberg
- Department of Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden.,Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden
| | - Erik Hedström
- Department of Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden. .,Department of Clinical Sciences Lund, Diagnostic Radiology, Lund University, Skane University Hospital, Lund, Sweden.
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Montgomery JA, Abdallah W, Yoneda ZT, Brittain E, Aznaurov SG, Parvez B, Adkins K, Whalen SP, Estrada J, Shen S, Crossley GH, Kanagasundram A, Saavedra P, Ellis CR, Lawson M, Darbar D, Shoemaker MB. Measurement of diffuse ventricular fibrosis with myocardial T1 in patients with atrial fibrillation. J Arrhythm 2016; 32:51-6. [PMID: 26949431 PMCID: PMC4759117 DOI: 10.1016/j.joa.2015.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/11/2015] [Accepted: 08/24/2015] [Indexed: 11/19/2022] Open
Abstract
Background Atrial fibrillation (AF) is associated with cardiac fibrosis, which can now be measured noninvasively using T1-mapping with cardiac magnetic resonance imaging (CMRI). This study aimed to assess the impact of AF on ventricular T1 at the time of CMRI. Methods Subjects with AF scheduled for AF ablation underwent CMRI with standard electrocardiography gating and breath-hold protocols on a 1.5 T scanner with post-contrast ventricular T1 recorded from 6 regions of interest at the mid-ventricle. Baseline demographic, clinical, and imaging characteristics were examined using univariate and multivariable linear regression modeling for an association with myocardial T1. Results One hundred fifty-seven patients were studied (32% women; median age, 61 years [interquartile range {IQR}, 55–67], 50% persistent AF [episodes>7 days or requiring electrical or pharmacologic cardioversion], 30% in AF at the time of the CMRI). The median global T1 was 404 ms (IQR, 381–428). AF at the time of CMRI was associated with a 4.4% shorter T1 (p=0.000) compared to sinus rhythm when adjusted for age, sex, persistent AF, body mass index, congestive heart failure, and renal dysfunction (estimated glomerular filtration rate<60). A post-hoc multivariate model adjusted for heart rate suggested that heart rate elevation (p=0.009) contributes to the reduction in T1 observed in patients with AF at the time of CMRI. No association between ventricular T1 and AF recurrence after ablation was demonstrated. Conclusion AF at the time of CMRI was associated with lower post-contrast ventricular T1 compared with sinus rhythm. This effect was at least partly due to elevated heart rate. T1 was not associated with the recurrence of AF after ablation.
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Affiliation(s)
- Jay A. Montgomery
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
- Correspondence to: Division of Cardiovascular Medicine, Vanderbilt University, 383 PRB, 2200 Pierce Avenue, Nashville, TN 37232-6300, USA. Tel.: +1 785 577 4575.
| | - Wissam Abdallah
- Spectrum Health Medical Group, 2900 Bradford St NE, Grand Rapids, MI 49525, USA
| | - Zachary T. Yoneda
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Evan Brittain
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Sam G. Aznaurov
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Babar Parvez
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Keith Adkins
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - S. Patrick Whalen
- Wake Forest Baptist Health Cardiology, 1 Medical Center Blvd, Winston-Salem, NC 27157, USA
| | - J.C. Estrada
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Sharon Shen
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - George H. Crossley
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Arvindh Kanagasundram
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Pablo Saavedra
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Christopher R. Ellis
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Mark Lawson
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - Dawood Darbar
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
| | - M. Benjamin Shoemaker
- Vanderbilt University Medical Center, 1211 Medical Center Drive, Nashville, TN 37232, USA
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Shao J, Rapacchi S, Nguyen KL, Hu P. Myocardial T1 mapping at 3.0 tesla using an inversion recovery spoiled gradient echo readout and bloch equation simulation with slice profile correction (BLESSPC) T1 estimation algorithm. J Magn Reson Imaging 2016; 43:414-25. [PMID: 26214152 PMCID: PMC4718899 DOI: 10.1002/jmri.24999] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 06/24/2015] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND To develop an accurate and precise myocardial T1 mapping technique using an inversion recovery spoiled gradient echo readout at 3.0 Tesla (T). THEORY AND METHODS The modified Look-Locker inversion-recovery (MOLLI) sequence was modified to use fast low angle shot (FLASH) readout, incorporating a BLESSPC (Bloch Equation Simulation with Slice Profile Correction) T1 estimation algorithm, for accurate myocardial T1 mapping. The FLASH-MOLLI with BLESSPC fitting was compared with different approaches and sequences with regards to T1 estimation accuracy, precision and image artifact based on simulation, phantom studies, and in vivo studies of 10 healthy volunteers and three patients at 3.0 Tesla. RESULTS The FLASH-MOLLI with BLESSPC fitting yields accurate T1 estimation (average error = -5.4 ± 15.1 ms, percentage error = -0.5% ± 1.2%) for T1 from 236-1852 ms and heart rate from 40-100 bpm in phantom studies. The FLASH-MOLLI sequence prevented off-resonance artifacts in all 10 healthy volunteers at 3.0T. In vivo, there was no significant difference between FLASH-MOLLI-derived myocardial T1 values and "ShMOLLI+IE" derived values (1458.9 ± 20.9 ms versus 1464.1 ± 6.8 ms, P = 0.50); However, the average precision by FLASH-MOLLI was significantly better than that generated by "ShMOLLI+IE" (1.84 ± 0.36% variance versus 3.57 ± 0.94%, P < 0.001). CONCLUSION The FLASH-MOLLI with BLESSPC fitting yields accurate and precise T1 estimation, and eliminates banding artifacts associated with bSSFP at 3.0T.
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Affiliation(s)
- Jiaxin Shao
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Stanislas Rapacchi
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Kim-Lien Nguyen
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Department of Medicine, Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Division of Cardiology, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Peng Hu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, CA, 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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McDiarmid AK, Broadbent DA, Higgins DM, Swoboda PP, Kidambi A, Ripley DP, Erhayiem B, Musa TA, Dobson LE, Greenwood JP, Plein S. The effect of changes to MOLLI scheme on T1 mapping and extra cellular volume calculation in healthy volunteers with 3 tesla cardiovascular magnetic resonance imaging. Quant Imaging Med Surg 2015; 5:503-10. [PMID: 26435913 DOI: 10.3978/j.issn.2223-4292.2015.04.07] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND Diffuse myocardial fibrosis may be quantified with magnetic resonance (MR) by calculating extracellular volume (ECV) fraction from native and post-contrast T1 values. The ideal modified look-locker inversion recovery (MOLLI) sequence for deriving T1 values has not been determined. This study aims to establish if systematic differences exist between suggested MOLLI schemes. METHODS Twelve phantom gels were studied with inversion recovery spin echo MR at 3.0 tesla to determine reference T1. Gels were then scanned with six MOLLI sequences (3s)3b(3s)5b; 4b(3s)3b(3s)2b; 5b(3s)3b with flip angles of both 35° and 50° at a range of heart rates (HRs). In 10 healthy volunteers MOLLI studies were performed on two separate occasions. Mid ventricular native and post contrast T1 was measured and ECV (%) calculated. RESULTS In phantoms, the co-efficient of variability at simulated HR [40-100] with a flip angle of 35° ranged from 6.77 to 9.55, and at 50° from 7.71 to 11.10. T1 was under-estimated by all MOLLI acquisitions. Error was greatest with longer T1, and increased as HR increased. The 10 volunteers had normal MR studies. Native T1 time was similar for all acquisitions but highest with the 5b(3s)3b 35° scheme (1,189.1±33.46 ms). Interstudy reproducibility was similar for all MOLLIs. CONCLUSIONS The 5b(3s)3b MOLLI scheme agreed best with reference T1, without statistical difference between the six schemes. The shorter breath-hold time of 5b(3s)3b scheme may be preferable in clinical studies and warrants further investigation.
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Affiliation(s)
- Adam K McDiarmid
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - David A Broadbent
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - David M Higgins
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - Peter P Swoboda
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - Ananth Kidambi
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - David P Ripley
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - Bara Erhayiem
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - Tarique A Musa
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - Laura E Dobson
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - John P Greenwood
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
| | - Sven Plein
- 1 Multidisciplinary Cardiovascular Research Centre (MCRC) & Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK ; 2 Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, UK
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Gai ND, Sandfort V, Liu S, Lima JAC, Bluemke DA. Dose correction for post-contrast T1 mapping of the heart: the MESA study. Int J Cardiovasc Imaging 2015; 32:271-279. [PMID: 26362875 DOI: 10.1007/s10554-015-0754-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/22/2015] [Indexed: 11/29/2022]
Abstract
Post-contrast myocardial T1 (T1(myo,c)) values have been shown to be sensitive to myocardial fibrosis. Recent studies have shown differences in results obtained from T1(myo,c) and extracellular volume fraction (ECV) with respect to percentage fibrosis. By exploring the relationship between blood plasma volume and T1(myo,c), the underlying basis for the divergence can be explained. Furthermore, dose administration based on body mass index (BMI), age and gender can mitigate the divergence in results. Inter-subject comparison of T1(myo,c) required adjustment for dose (in mmol/kg), time and glomerular filtration rate. Further adjustment for effective dose based on lean muscle mass reflected by blood/plasma volume was performed. A test case of 605 subjects from the MESA study who had undergone pre- and post-contrast T1 mapping was studied. T1(myo,c) values were compared between subjects with and without metabolic syndrome (MetS), between smoking and non-smoking subjects, and subjects with and without impaired glucose tolerance, before and after dose adjustment based on plasma volume. Comparison with ECV (which is dose independent), pre-contrast myocardial T1 and blood normalized myocardial T1 values was also performed to validate the correction. There were significant differences in T1(myo,c) (post plasma volume correction) and ECV between current and former smokers (p value 0.017 and 0.01, respectively) but not T1(myo,c) prior to correction (p = 0.12). Prior to dose adjustment for plasma volume, p value was <0.001 for T1(myo,c) between MetS and non-MetS groups and was 0.13 between subjects with and without glucose intolerance; after adjustment for PV, p value was 0.63 and 0.99. Corresponding ECV p values were 0.44 and 0.99, respectively. Overall, ECV results showed the best agreement with PV corrected T1(myo,c) (mean absolute difference in p values = 0.073) and pre-contrast myocardial T1 in comparison with other measures (T1(myo,c( prior to correction, blood/plasma T1 value normalized myocardium). Weight-based contrast dosing administered in mmol/kg results in a bias in T1 values which can lead to erroneous conclusions. After adjustment for lean muscle mass based on plasma volume, results from T1(myo,c) were in line with ECV derived results. Furthermore, the use of a modified equivalent dose adjusted for BMI, age, sex and hematocrit can be adopted for quantitative imaging.
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Affiliation(s)
- Neville D Gai
- Radiology and Imaging Sciences (RAD&IS), National Institutes of Health/Clinical Center, 9000 Rockville Pike, Bldg 10, Bethesda, MD, 20892, USA.
| | - Veit Sandfort
- Radiology and Imaging Sciences (RAD&IS), National Institutes of Health/Clinical Center, 9000 Rockville Pike, Bldg 10, Bethesda, MD, 20892, USA
| | - Songtao Liu
- Radiology and Imaging Sciences (RAD&IS), National Institutes of Health/Clinical Center, 9000 Rockville Pike, Bldg 10, Bethesda, MD, 20892, USA
| | | | - David A Bluemke
- Radiology and Imaging Sciences (RAD&IS), National Institutes of Health/Clinical Center, 9000 Rockville Pike, Bldg 10, Bethesda, MD, 20892, USA.,NIBIB, Bethesda, MD, USA
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Sussman MS, Yang IY, Fok KH, Wintersperger BJ. Inversion group (IG) fitting: A new T1
mapping method for modified look-locker inversion recovery (MOLLI) that allows arbitrary inversion groupings and rest periods (including no rest period). Magn Reson Med 2015; 75:2332-40. [DOI: 10.1002/mrm.25829] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 05/14/2015] [Accepted: 06/09/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Marshall S. Sussman
- Joint Department of Medical Imaging; University Health Network, University of Toronto; Toronto, Ontario Canada
- Department of Medical Imaging; University of Toronto; Toronto, Ontario
| | - Issac Y. Yang
- Joint Department of Medical Imaging; University Health Network, University of Toronto; Toronto, Ontario Canada
| | - Kai-Ho Fok
- Joint Department of Medical Imaging; University Health Network, University of Toronto; Toronto, Ontario Canada
| | - Bernd J. Wintersperger
- Joint Department of Medical Imaging; University Health Network, University of Toronto; Toronto, Ontario Canada
- Department of Medical Imaging; University of Toronto; Toronto, Ontario
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Kachenoura N, Besson-Hajji L, Graves MJ, Reid S, Soulat G, Ashrafpoor G, De Cesare A, Hagege A, Redheuil A, Mousseaux E. Kinetic index combining native and postcontrast myocardial T1 in hypertrophic cardiomyopathy. J Magn Reson Imaging 2015; 42:1713-22. [DOI: 10.1002/jmri.24947] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 04/28/2015] [Indexed: 01/19/2023] Open
Affiliation(s)
- Nadjia Kachenoura
- Sorbonne Universités, UPMC Univ Paris 06, INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale; F-75013 Paris France
| | - Laila Besson-Hajji
- Sorbonne Universités, UPMC Univ Paris 06, INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale; F-75013 Paris France
- Service de Radiologie Cardiovasculaire, Hôpital Européen Georges Pompidou; Paris France
- Paris-Centre de recherche Cardiovasculaire, HEGP, INSERM; Paris France
- Université Paris Descartes, Sorbonne Paris Cité Universités, Faculté de médecine; Paris France
| | - Martin J Graves
- Radiology department; Cambridge University Hospitals NHS Foundation Trust; UK
| | | | - Gilles Soulat
- Service de Radiologie Cardiovasculaire, Hôpital Européen Georges Pompidou; Paris France
- Paris-Centre de recherche Cardiovasculaire, HEGP, INSERM; Paris France
- Université Paris Descartes, Sorbonne Paris Cité Universités, Faculté de médecine; Paris France
| | - Golmehr Ashrafpoor
- Sorbonne Universités, UPMC Univ Paris 06, INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale; F-75013 Paris France
- Service de Radiologie Cardiovasculaire, Hôpital Européen Georges Pompidou; Paris France
| | - Alain De Cesare
- Sorbonne Universités, UPMC Univ Paris 06, INSERM 1146, CNRS 7371, Laboratoire d'Imagerie Biomédicale; F-75013 Paris France
| | - Albert Hagege
- Paris-Centre de recherche Cardiovasculaire, HEGP, INSERM; Paris France
- Université Paris Descartes, Sorbonne Paris Cité Universités, Faculté de médecine; Paris France
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Department of Cardiology; Paris France
| | - Alban Redheuil
- Department of Cardiovascular Radiology; Institut de Cardiologie, Hôpital Pitié-Salpêtrière; Paris France
- Imaging Core Lab; ICAN; Paris France
| | - Elie Mousseaux
- Service de Radiologie Cardiovasculaire, Hôpital Européen Georges Pompidou; Paris France
- Paris-Centre de recherche Cardiovasculaire, HEGP, INSERM; Paris France
- Université Paris Descartes, Sorbonne Paris Cité Universités, Faculté de médecine; Paris France
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BLOCH equations-based reconstruction of myocardium t1 maps from modified look-locker inversion recovery sequence. PLoS One 2015; 10:e0126766. [PMID: 25962182 PMCID: PMC4427396 DOI: 10.1371/journal.pone.0126766] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 04/07/2015] [Indexed: 11/19/2022] Open
Abstract
Modified Look-Locker Inversion recovery (MOLLI) sequence is increasingly performed for myocardial T1 mapping but is known to underestimate T1 values. The aim of the study was to quantitatively analyze several sources of errors when T1 maps are derived using standard post-processing of the sequence and to propose a reconstruction approach that takes into account inversion efficacy (η), T2 relaxation during balanced steady-state free-precession readouts and B1+ inhomogeneities. Contributions of the different sources of error were analyzed using Bloch equations simulations of MOLLI sequence. Bloch simulations were then combined with the acquisition of fast B1+ and T2 maps to derive more accurate T1 maps. This novel approach was evaluated on phantoms and on five healthy volunteers. Simulations show that T2 variations, B1+ heterogeneities and inversion efficiency represent major confounders for T1 mapping when MOLLI is processed with standard 3-parameters fitting. In vitro data indicate that T1 values are accurately derived with the simulation approach and in vivo data suggest that myocardium T1 are 15% underestimated when processed with the standard 3-parameters fitting. At the cost of additional acquisitions, this method might be suitable in clinical research protocols for precise tissue characterization as it decorrelates T1 and T2 effects on parametric maps provided by MOLLI sequence and avoids inaccuracies when B1+ is not homogenous throughout the myocardium.
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Selection of magnetization catalyzation and readout methods for modified Look-Locker inversion recovery: a T1 mapping primer. Magn Reson Imaging 2015; 33:363-73. [PMID: 25660643 DOI: 10.1016/j.mri.2015.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/15/2015] [Accepted: 02/01/2015] [Indexed: 01/13/2023]
Abstract
BACKGROUND The purpose of this work was to evaluate different magnetization preparation and readout sequences for modified Look-Locker inversion recovery (MOLLI) toward improved T1 mapping in the heart. Elements investigated include: catalyzation sequences to prepare the magnetization before readout, alternate k-space trajectories, a spoiled gradient recalled echo readout, and a 5b(3b)3b MOLLI sampling scheme ('b' denoting beats). METHODS Conventional 3b(3b)3b(3b)5b MOLLI with a linear k-space trajectory was compared to four variants in simulations, in vitro and in vivo (at 3T). Variants were centric conventional MOLLI, centric-paired conventional MOLLI, linear 5b(3b)3b MOLLI and spoiled gradient recalled echo MOLLI. Each of these was applied with three magnetization catalyzation methods, and T1 measurement accuracy and precision were evaluated in simulations via a Monte Carlo algorithm, in a set of calibrated phantoms, and in ten healthy volunteers. Contrast-to-noise, heart rate dependence and B1+ dependence were also evaluated. RESULTS A linear k-space trajectory was superior in vitro to centric and centric-paired trajectories. Of the catalyzation methods, preparation of transverse magnetization only-using a linearly increasing flip angle catalyzation-improved MOLLI T1 measurement accuracy, precision, and map quality versus methods that include catalyzation of the longitudinal magnetization. The 5b(3b)3b MOLLI scheme offered comparable native T1 measurement accuracy and precision to conventional MOLLI, despite its shortened acquisition. CONCLUSIONS MOLLI T1 measurement accuracy, precision, and map quality depend on the method of catalyzation of magnetization prior to image acquisition, as well as on the readout method and MOLLI sampling scheme used.
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T1 mapping: characterisation of myocardial interstitial space. Insights Imaging 2014; 6:189-202. [PMID: 25424598 PMCID: PMC4376813 DOI: 10.1007/s13244-014-0366-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/23/2014] [Accepted: 10/28/2014] [Indexed: 01/19/2023] Open
Abstract
Abstract Myocardial fibrosis is always present in end-stage heart failure and is a major independent predictor of adverse cardiac outcome. Cardiac magnetic resonance (CMR) is an imaging method that permits a non-invasive assessment of the heart and has been established as the “gold standard” for the evaluation of cardiac anatomy and function, as well as for quantifying focal myocardial fibrosis in both ischaemic and non-ischaemic heart disease. However, cardiac pathologies characterised by diffuse myocardial fibrosis cannot be evaluated by late gadolinium enhancement (LGE) imaging, as there are no reference regions of normal myocardium. Recent improvements in CMR imaging techniques have enabled parametric mapping of relaxation properties (T1, T2 and T2*) clinically feasible within a single breath-hold. T1 mapping techniques performed both with and without contrast enable the quantification of diffuse myocardial fibrosis and myocardial infiltration. This article reviews current imaging techniques, emerging applications and the future potential and limitations of CMR for T1 mapping. Teaching points • Myocardial fibrosis is a common endpoint in a variety of cardiac diseases. • Myocardial fibrosis results in myocardial stiffness, heart failure, arrhythmia and sudden death. • T1-mapping CMR techniques enable the quantification of diffuse myocardial fibrosis. • Native T1 reflects myocardial disease involving the myocyte and interstitium. • The use of gadolinium allows measurement of the extracellular volume fraction, reflecting interstitial space.
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Mahmod M, Piechnik SK, Levelt E, Ferreira VM, Francis JM, Lewis A, Pal N, Dass S, Ashrafian H, Neubauer S, Karamitsos TD. Adenosine stress native T1 mapping in severe aortic stenosis: evidence for a role of the intravascular compartment on myocardial T1 values. J Cardiovasc Magn Reson 2014; 16:92. [PMID: 25410203 PMCID: PMC4237748 DOI: 10.1186/s12968-014-0092-y] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 11/04/2014] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Myocardial T1 relaxation times have been reported to be markedly abnormal in diverse myocardial pathologies, ascribed to interstitial changes, evaluated by T1 mapping and calculation of extracellular volume (ECV). T1 mapping is sensitive to myocardial water content of both intra- and extracellular in origin, but the effect of intravascular compartment changes on T1 has been largely neglected. We aimed to assess the role of intravascular compartment on native (pre-contrast) T1 values by studying the effect of adenosine-induced vasodilatation in patients with severe aortic stenosis (AS) before and after aortic valve replacement (AVR). METHODS 42 subjects (26 patients with severe AS without obstructive coronary artery disease and 16 controls) underwent cardiovascular magnetic resonance at 3 T for native T1-mapping (ShMOLLI), first-pass perfusion (myocardial perfusion reserve index-MPRI) at rest and during adenosine stress, and late gadolinium enhancement (LGE). RESULTS AS patients had increased resting myocardial T1 (1196±47 ms vs. 1168±27 ms, p=0.037), reduced MPRI (0.92±0.31 vs. 1.74±0.32, p<0.001), and increased left ventricular mass index (LVMI) and LGE volume compared to controls. During adenosine stress, T1 in AS was similar to controls (1240±51 ms vs. 1238±54 ms, p=0.88), possibly reflecting a similar level of maximal coronary vasodilatation in both groups. Conversely, the T1 response to stress was blunted in AS (ΔT1 3.7±2.7% vs. 6.0±4.2% in controls, p=0.013). Seven months after AVR (n=16) myocardial T1 and response to adenosine stress recovered towards normal. Native T1 values correlated with reduced MPRI, aortic valve area, and increased LVMI. CONCLUSIONS Our study suggests that native myocardial T1 values are not only influenced by interstitial and intracellular water changes, but also by changes in the intravascular compartment. Performing T1 mapping during or soon after vasodilator stress may affect ECV measurements given that hyperemia alone appears to substantially alter T1 values.
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Affiliation(s)
- Masliza Mahmod
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Stefan K Piechnik
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Eylem Levelt
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Vanessa M Ferreira
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Jane M Francis
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Andrew Lewis
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Nikhil Pal
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Sairia Dass
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Houman Ashrafian
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Stefan Neubauer
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
| | - Theodoros D Karamitsos
- />University of Oxford Centre for Clinical Magnetic Resonance Research (OCMR), Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, Oxford, OX3 9DU UK
- />1st Department of Cardiology, AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki, 54636 Greece
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48
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Hong K, Kim D. MOLLI and AIR T1 mapping pulse sequences yield different myocardial T1 and ECV measurements. NMR IN BIOMEDICINE 2014; 27:1419-1426. [PMID: 25323070 PMCID: PMC4226275 DOI: 10.1002/nbm.3221] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/24/2014] [Accepted: 08/28/2014] [Indexed: 05/29/2023]
Abstract
Both post-contrast myocardial T1 and extracellular volume (ECV) have been reported to be associated with diffuse interstitial fibrosis. Recently, the cardiovascular magnetic resonance (CMR) field is recognizing that post-contrast myocardial T1 is sensitive to several confounders and migrating towards ECV as a measure of collagen volume fraction. Several recent studies using widely available Modified Look-Locker Inversion-recovery (MOLLI) have reported ECV cutoff values to distinguish between normal and diseased myocardium. It is unclear if these cutoff values are translatable to different T1 mapping pulse sequences such as arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping, which was recently developed to rapidly image patients with cardiac rhythm disorders. We sought to evaluate, in well-controlled canine and pig experiments, the relative accuracy and precision, as well as intra- and inter-observer variability in data analysis, of ECV measured with AIR as compared with MOLLI. In 16 dogs, as expected, the mean T1 was significantly different (p < 0.001) between MOLLI (891 ± 373 ms) and AIR (1071 ± 503 ms), but, surprisingly, the mean ECV between MOLLI (21.8 ± 2.1%) and AIR (19.6 ± 2.4%) was also significantly different (p < 0.001). Both intra- and inter-observer agreements in T1 calculations were higher for MOLLI than AIR, but intra- and inter-observer agreements in ECV calculations were similar between MOLLI and AIR. In six pigs, the coefficient of repeatability (CR), as defined by the Bland-Altman analysis, in T1 calculation was considerably lower for MOLLI (32.5 ms) than AIR (82.3 ms), and the CR in ECV calculation was also lower for MOLLI (1.8%) than AIR (4.5%). In conclusion, this study shows that MOLLI and AIR yield significantly different T1 and ECV values in large animals and that MOLLI yields higher precision than AIR. Findings from this study suggest that CMR researchers must consider the specific pulse sequence when translating published ECV cutoff values into their own studies.
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Affiliation(s)
- KyungPyo Hong
- Department of Bioengineering, University of Utah, Salt Lake City, UT, 84112
- UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, 84108
| | - Daniel Kim
- UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, 84108
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Cooper MA, Nguyen TD, Spincemaille P, Prince MR, Weinsaft JW, Wang Y. How accurate is MOLLI T1 mapping in vivo? Validation by spin echo methods. PLoS One 2014; 9:e107327. [PMID: 25211243 PMCID: PMC4161413 DOI: 10.1371/journal.pone.0107327] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/12/2014] [Indexed: 01/04/2023] Open
Abstract
T1 mapping is a promising quantitative tool for assessing diffuse cardiomyopathies. The purpose of this study is to quantify in vivo accuracy of the Modified Look-Locker Inversion Recovery (MOLLI) cardiac T1 mapping sequence against the spin echo gold standard, which has not been done previously. T1 accuracy of MOLLI was determined by comparing with the gold standard inversion recovery spin echo sequence in the calf muscle, and with a rapid inversion recovery fast spin echo sequence in the heart. T1 values were obtained with both conventional MOLLI fitting and MOLLI fitting with inversion efficiency correction. In the calf (n = 6), conventional MOLLI fitting produced inconsistent T1 values with error ranging from 8.0% at 90° to 17.3% at 30°. Modified MOLLI fitting with inversion efficiency correction improved error to under 7.4% at all flip angles. In the heart (n = 5), modified MOLLI fitting with inversion correction reduced T1 error to 5.5% from 14.0% by conventional MOLLI fitting. This study shows that conventional MOLLI fitting can lead to significant in vivo T1 errors when not accounting for the lower adiabatic inversion efficiency often experienced in vivo.
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Affiliation(s)
- Mitchell A. Cooper
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
- Department of Radiology, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail:
| | - Thanh D. Nguyen
- Department of Radiology, Weill Cornell Medical College, New York, New York, United States of America
| | - Pascal Spincemaille
- Department of Radiology, Weill Cornell Medical College, New York, New York, United States of America
| | - Martin R. Prince
- Department of Radiology, Weill Cornell Medical College, New York, New York, United States of America
| | - Jonathan W. Weinsaft
- Department of Radiology, Weill Cornell Medical College, New York, New York, United States of America
- Division of Cardiology, Department of Medicine, Weill Cornell Medical College, New York, New York, United States of America
| | - Yi Wang
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, United States of America
- Department of Radiology, Weill Cornell Medical College, New York, New York, United States of America
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50
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Sado DM, Maestrini V, Piechnik SK, Banypersad SM, White SK, Flett AS, Robson MD, Neubauer S, Ariti C, Arai A, Kellman P, Yamamura J, Schoennagel BP, Shah F, Davis B, Trompeter S, Walker M, Porter J, Moon JC. Noncontrast myocardial T1 mapping using cardiovascular magnetic resonance for iron overload. J Magn Reson Imaging 2014; 41:1505-11. [PMID: 25104503 DOI: 10.1002/jmri.24727] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/31/2014] [Indexed: 12/18/2022] Open
Abstract
PURPOSE To explore the use and reproducibility of magnetic resonance-derived myocardial T1 mapping in patients with iron overload. MATERIALS AND METHODS The research received ethics committee approval and all patients provided written informed consent. This was a prospective study of 88 patients and 67 healthy volunteers. Thirty-five patients underwent repeat scanning for reproducibility. T1 mapping used the shortened modified Look-Locker inversion recovery sequence (ShMOLLI) with a second, confirmatory MOLLI sequence in the reproducibility group. T2 * was performed using a commercially available sequence. The analysis of the T2 * interstudy reproducibility data was performed by two different research groups using two different methods. RESULTS Myocardial T1 was lower in patients than healthy volunteers (836 ± 138 msec vs. 968 ± 32 msec, P < 0.0001). Myocardial T1 correlated with T2 * (R = 0.79, P < 0.0001). No patient with low T2 * had normal T1 , but 32% (n = 28) of cases characterized by a normal T2 * had low myocardial T1 . Interstudy reproducibility of either T1 sequence was significantly better than T2 *, with the results suggesting that the use of T1 in clinical trials could decrease potential sample sizes by 7-fold. CONCLUSION Myocardial T1 mapping is an alternative method for cardiac iron quantification. T1 mapping shows the potential for improved detection of mild iron loading. The superior reproducibility of T1 has potential implications for clinical trial design and therapeutic monitoring.
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Affiliation(s)
- Daniel M Sado
- The Heart Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | - Viviana Maestrini
- Department of Cardiovascular, Respiratory, Nephrology and Geriatrics Sciences, La Sapienza, University of Rome, Rome, Italy
| | - Stefan K Piechnik
- Oxford Centre for Clinical Magnetic Resonance Research, Department of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Sanjay M Banypersad
- The Heart Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | - Steven K White
- The Heart Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | | | - Matthew D Robson
- Oxford Centre for Clinical Magnetic Resonance Research, Department of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Stefan Neubauer
- Oxford Centre for Clinical Magnetic Resonance Research, Department of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Cono Ariti
- Department of Statistics, London School of Hygiene and Tropical Medicine, London, UK
| | - Andrew Arai
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Peter Kellman
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jin Yamamura
- University Medical Centre Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany
| | - Bjoern P Schoennagel
- University Medical Centre Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg, Germany
| | | | | | | | - Malcolm Walker
- The Heart Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
| | | | - James C Moon
- The Heart Hospital, London, UK.,Institute of Cardiovascular Science, University College London, London, UK
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