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Alemany I, Rose JN, Ferreira PF, Pennell DJ, Nielles‐Vallespin S, Scott AD, Doorly DJ. Realistic numerical simulations of diffusion tensor cardiovascular magnetic resonance: The effects of perfusion and membrane permeability. Magn Reson Med 2023; 90:1641-1656. [PMID: 37415339 PMCID: PMC10952789 DOI: 10.1002/mrm.29737] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/19/2023] [Accepted: 05/16/2023] [Indexed: 07/08/2023]
Abstract
PURPOSE To study the sensitivity of diffusion tensor cardiovascular magnetic resonance (DT-CMR) to microvascular perfusion and changes in cell permeability. METHODS Monte Carlo (MC) random walk simulations in the myocardium have been performed to simulate self-diffusion of water molecules in histology-based media with varying extracellular volume fraction (ECV) and permeable membranes. The effect of microvascular perfusion on simulations of the DT-CMR signal has been incorporated by adding the contribution of particles traveling through an anisotropic capillary network to the diffusion signal. The simulations have been performed considering three pulse sequences with clinical gradient strengths: monopolar stimulated echo acquisition mode (STEAM), monopolar pulsed-gradient spin echo (PGSE), and second-order motion-compensated spin echo (MCSE). RESULTS Reducing ECV intensifies the diffusion restriction and incorporating membrane permeability reduces the anisotropy of the diffusion tensor. Widening the intercapillary velocity distribution results in increased measured diffusion along the cardiomyocytes long axis when the capillary networks are anisotropic. Perfusion amplifies the mean diffusivity for STEAM while the opposite is observed for short diffusion encoding time sequences (PGSE and MCSE). CONCLUSION The effect of perfusion on the measured diffusion tensor is reduced using an increased reference b-value. Our results pave the way for characterization of the response of DT-CMR to microstructural changes underlying cardiac pathology and highlight the higher sensitivity of STEAM to permeability and microvascular circulation due to its longer diffusion encoding time.
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Affiliation(s)
- Ignasi Alemany
- Department of AeronauticsImperial College LondonLondonUK
- Cardiovascular Magnetic Resonance Unit, Royal Brompton HospitalGuy's and St Thomas' NHS Foundation TrustLondonUK
| | - Jan N. Rose
- Department of AeronauticsImperial College LondonLondonUK
| | - Pedro F. Ferreira
- Cardiovascular Magnetic Resonance Unit, Royal Brompton HospitalGuy's and St Thomas' NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Dudley J. Pennell
- Cardiovascular Magnetic Resonance Unit, Royal Brompton HospitalGuy's and St Thomas' NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Sonia Nielles‐Vallespin
- Cardiovascular Magnetic Resonance Unit, Royal Brompton HospitalGuy's and St Thomas' NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Andrew D. Scott
- Cardiovascular Magnetic Resonance Unit, Royal Brompton HospitalGuy's and St Thomas' NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
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Simultaneous Quantification of Anisotropic Microcirculation and Microstructure in Peripheral Nerve. J Clin Med 2022; 11:jcm11113036. [PMID: 35683424 PMCID: PMC9181650 DOI: 10.3390/jcm11113036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/16/2022] [Accepted: 05/25/2022] [Indexed: 02/04/2023] Open
Abstract
Peripheral nerve injury is a significant public health challenge, and perfusion in the nerve is a potential biomarker for assessing the injury severity and prognostic outlook. Here, we applied a novel formalism that combined intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) to simultaneously characterize anisotropic microcirculation and microstructure in the rat sciatic nerve. Comparison to postmortem measurements revealed that the in vivo IVIM-DTI signal contained a fast compartment (2.32 ± 0.04 × 10−3 mm2/s mean diffusivity, mean ± sem, n = 6, paired t test p < 0.01) that could be attributed to microcirculation in addition to a slower compartment that had similar mean diffusivity as the postmortem nerve (1.04 ± 0.01 vs. 0.96 ± 0.05 × 10−3 mm2/s, p > 0.05). Although further investigation and technical improvement are warranted, this preliminary study demonstrates both the feasibility and potential for applying the IVIM-DTI methodology to peripheral nerves for quantifying perfusion in the presence of anisotropic tissue microstructure.
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Wang DJJ, Le Bihan D, Krishnamurthy R, Smith M, Ho ML. Noncontrast Pediatric Brain Perfusion: Arterial Spin Labeling and Intravoxel Incoherent Motion. Magn Reson Imaging Clin N Am 2021; 29:493-513. [PMID: 34717841 DOI: 10.1016/j.mric.2021.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Noncontrast magnetic resonance imaging techniques for measuring brain perfusion include arterial spin labeling (ASL) and intravoxel incoherent motion (IVIM). These techniques provide noninvasive and repeatable assessment of cerebral blood flow or cerebral blood volume without the need for intravenous contrast. This article discusses the technical aspects of ASL and IVIM with a focus on normal physiologic variations, technical parameters, and artifacts. Multiple pediatric clinical applications are presented, including tumors, stroke, vasculopathy, vascular malformations, epilepsy, migraine, trauma, and inflammation.
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Affiliation(s)
- Danny J J Wang
- USC Institute for Neuroimaging and Informatics, SHN, 2025 Zonal Avenue, Health Sciences Campus, Los Angeles, CA 90033, USA
| | - Denis Le Bihan
- NeuroSpin, Centre d'études de Saclay, Bâtiment 145, Gif-sur-Yvette 91191, France
| | - Ram Krishnamurthy
- Department of Radiology, Nationwide Children's Hospital, 700 Children's Drive - ED4, Columbus, OH 43205, USA
| | - Mark Smith
- Department of Radiology, Nationwide Children's Hospital, 700 Children's Drive - ED4, Columbus, OH 43205, USA
| | - Mai-Lan Ho
- Department of Radiology, Nationwide Children's Hospital, 700 Children's Drive - ED4, Columbus, OH 43205, USA.
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Englund EK, Reiter DA, Shahidi B, Sigmund EE. Intravoxel Incoherent Motion Magnetic Resonance Imaging in Skeletal Muscle: Review and Future Directions. J Magn Reson Imaging 2021; 55:988-1012. [PMID: 34390617 DOI: 10.1002/jmri.27875] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 12/29/2022] Open
Abstract
Throughout the body, muscle structure and function can be interrogated using a variety of noninvasive magnetic resonance imaging (MRI) methods. Recently, intravoxel incoherent motion (IVIM) MRI has gained momentum as a method to evaluate components of blood flow and tissue diffusion simultaneously. Much of the prior research has focused on highly vascularized organs, including the brain, kidney, and liver. Unique aspects of skeletal muscle, including the relatively low perfusion at rest and large dynamic range of perfusion between resting and maximal hyperemic states, may influence the acquisition, postprocessing, and interpretation of IVIM data. Here, we introduce several of those unique features of skeletal muscle; review existing studies of IVIM in skeletal muscle at rest, in response to exercise, and in disease states; and consider possible confounds that should be addressed for muscle-specific evaluations. Most studies used segmented nonlinear least squares fitting with a b-value threshold of 200 sec/mm2 to obtain IVIM parameters of perfusion fraction (f), pseudo-diffusion coefficient (D*), and diffusion coefficient (D). In healthy individuals, across all muscles, the average ± standard deviation of D was 1.46 ± 0.30 × 10-3 mm2 /sec, D* was 29.7 ± 38.1 × 10-3 mm2 /sec, and f was 11.1 ± 6.7%. Comparisons of reported IVIM parameters in muscles of the back, thigh, and leg of healthy individuals showed no significant difference between anatomic locations. Throughout the body, exercise elicited a positive change of all IVIM parameters. Future directions including advanced postprocessing models and potential sequence modifications are discussed. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Erin K Englund
- Department of Radiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - David A Reiter
- Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia, USA.,Department of Orthopedics, Emory University, Atlanta, Georgia, USA
| | - Bahar Shahidi
- Department of Orthopaedic Surgery, UC San Diego, San Diego, California, USA
| | - Eric E Sigmund
- Department of Radiology, New York University Grossman School of Medicine, NYU Langone Health, New York, New York, USA.,Center for Advanced Imaging and Innovation (CAI2R), Bernard and Irene Schwarz Center for Biomedical Imaging (CBI), NYU Langone Health, New York, New York, USA
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Zhang XS, Liu EH, Wang XY, Zhou XX, Zhang HX, Zhu YM, Sang XQ, Kuai ZX. Short-Term Repeatability of in Vivo Cardiac Intravoxel Incoherent Motion Tensor Imaging in Healthy Human Volunteers. J Magn Reson Imaging 2021; 55:854-865. [PMID: 34296813 DOI: 10.1002/jmri.27847] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Intravoxel incoherent motion (IVIM) tensor imaging is a promising technique for diagnosis and monitoring of cardiovascular diseases. Knowledge about measurement repeatability, however, remains limited. PURPOSE To evaluate short-term repeatability of IVIM tensor imaging in normal in vivo human hearts. STUDY TYPE Prospective. POPULATION Ten healthy subjects without history of heart diseases. FIELD STRENGTH/SEQUENCE Balanced steady-state free-precession cine sequence and single-shot spin-echo echo planar IVIM tensor imaging sequence (9 b-values, 0-400 seconds/mm2 and six diffusion-encoding directions) at 3.0 T. ASSESSMENT Subjects were scanned twice with an interval of 15 minutes, leaving the scanner between studies. The signal-to-noise ratio (SNR) was evaluated in anterior, lateral, septal, and inferior segments of the left ventricle wall. Fractional anisotropy (FA), mean diffusivity (MD), mean fraction (MF), and helix angle (HA) in the four segments were independently measured by five radiologists. STATISTICAL TESTS IVIM tensor indexes were compared between observers using a one-way analysis of variance or between scans using a paired t-test (normal data) or a Wilcoxon rank-sum test (non-normal data). Interobserver agreement and test-retest repeatability were assessed using the intraclass correlation coefficient (ICC), within-subject coefficient of variation (WCV), and Bland-Altman limits of agreements. RESULTS SNR of inferior segment was significantly lower than the other three segments, and inferior segment was therefore excluded from repeatability analysis. Interobserver repeatability was excellent for all IVIM tensor indexes (ICC: 0.886-0.972; WCV: 0.62%-4.22%). Test-retest repeatability was excellent for MD of the self-diffusion tensor (D) and MF of the perfusion fraction tensor (fp ) (ICC: 0.803-0.888; WCV: 1.42%-9.51%) and moderate for FA and MD of the pseudo-diffusion tensor (D* ) (ICC: 0.487-0.532; WCV: 6.98%-10.89%). FA of D and fp and HA of D presented good test-retest repeatability (ICC: 0.732-0.788; WCV: 3.28%-8.71%). DATA CONCLUSION The D and fp indexes exhibited satisfactory repeatability, but further efforts were needed to improve repeatability of D* indexes. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Xiu-Shi Zhang
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, China
| | - En-Hui Liu
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, China
| | - Xin-Yu Wang
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, China
| | - Xin-Xiang Zhou
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, China
| | - Hong-Xia Zhang
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, China
| | - Yue-Min Zhu
- CREATIS, CNRS UMR 5220-INSERM U1206-University Lyon 1-INSA Lyon-University Jean Monnet Saint-Etienne, Lyon, France
| | - Xi-Qiao Sang
- Division of Respiratory Disease, The Fourth Hospital of Harbin Medical University, Harbin, China
| | - Zi-Xiang Kuai
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, China
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6
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Zhang XS, Sang XQ, Kuai ZX, Zhang HX, Lou J, Lu Q, Zhu YM. Investigation of intravoxel incoherent motion tensor imaging for the characterization of the in vivo human heart. Magn Reson Med 2020; 85:1414-1426. [PMID: 32989786 DOI: 10.1002/mrm.28523] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE To investigate intravoxel incoherent motion (IVIM) tensor imaging of the in vivo human heart and elucidate whether the estimation of IVIM tensors is affected by the complexity of pseudo-diffusion components in myocardium. METHODS The cardiac IVIM data of 10 healthy subjects were acquired using a diffusion weighted spin-echo echo-planar imaging sequence along 6 gradient directions with 10 b values (0~400 s/mm2 ). The IVIM data of left ventricle myocardium were fitted to the IVIM tensor model. The complexity of myocardial pseudo-diffusion components was reduced through exclusion of low b values (0 and 5 s/mm2 ) from the IVIM curve-fitting analysis. The fractional anisotropy, mean fraction/mean diffusivity, and Westin measurements of pseudo-diffusion tensors (fp and D*) and self-diffusion tensor (D), as well as the angle between the main eigenvector of fp (or D*) and that of D, were computed and compared before and after excluding low b values. RESULTS The fractional anisotropy values of fp and D* without low b value participation were significantly higher (P < .001) than those with low b value participation, but an opposite trend was found for the mean fraction/diffusivity values. Besides, after removing low b values, the angle between the main eigenvector of fp (or D*) and that of D became small, and both fp and D* tensors presented significant decrease of spherical components and significant increase of linear components. CONCLUSION The presence of multiple pseudo-diffusion components in myocardium indeed influences the estimation of IVIM tensors. The IVIM tensor model needs to be further improved to account for the complexity of myocardial microcirculatory network and blood flow.
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Affiliation(s)
- Xiu-Shi Zhang
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, People's Republic of China
| | - Xi-Qiao Sang
- Division of Respiratory Disease, The Fourth Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Zi-Xiang Kuai
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, People's Republic of China
| | - Hong-Xia Zhang
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, People's Republic of China
| | - Jie Lou
- Imaging Center, Harbin Medical University Cancer Hospital, Harbin, People's Republic of China
| | - Qing Lu
- Department of Radiology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Yue-Min Zhu
- Univ Lyon, INSA Lyon, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621, Lyon, France
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Jang M, Jin S, Kang M, Han S, Cho H. Pattern recognition analysis of directional intravoxel incoherent motion MRI in ischemic rodent brains. NMR IN BIOMEDICINE 2020; 33:e4268. [PMID: 32067300 DOI: 10.1002/nbm.4268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 01/14/2020] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
This study aimed to demonstrate a reliable automatic segmentation method for independently separating reduced diffusion and decreased perfusion areas in ischemic stroke brains using constrained nonnegative matrix factorization (cNMF) pattern recognition in directional intravoxel incoherent motion MRI (IVIM-MRI). First, the feasibility of cNMF-based segmentation of IVIM signals was investigated in both simulations and in vivo experiments. The cNMF analysis was independently performed for S0 -normalized and scaled (by the difference between the maximum and minimum) IVIM signals, respectively. Segmentations of reduced diffusion (from S0 -normalized IVIM signals) and decreased perfusion (from scaled IVIM signals) areas were performed using the corresponding cNMF pattern weight maps. Second, Monte Carlo simulations were performed for directional IVIM signals to investigate the relationship between the degree of vessel alignment and the direction of the diffusion gradient. Third, directional IVIM-MRI experiments (x, y and z diffusion-gradient directions, 20 b values at 7 T) were performed for normal (n = 4), sacrificed (n = 1, no flow) and ischemic stroke models (n = 4, locally reduced flow). The results showed that automatic segmentation of the hypoperfused lesion using cNMF analysis was more accurate than segmentation using the conventional double-exponential fitting. Consistent with the simulation, the double-exponential pattern of the IVIM signals was particularly strong in white matter and ventricle regions when the directional flows were aligned with the applied diffusion-gradient directions. cNMF analysis of directional IVIM signals allowed robust automated segmentation of white matter, ventricle, vascular and hypoperfused regions in the ischemic brain. In conclusion, directional IVIM signals were simultaneously sensitive to diffusion and aligned flow and were particularly useful for automatically segmenting ischemic lesions via cNMF-based pattern recognition.
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Affiliation(s)
- MinJung Jang
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Seokha Jin
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - MungSoo Kang
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - SoHyun Han
- Center for Neuroscience Imaging Research, Institute of Basic Science (IBS), Suwon, South Korea
| | - HyungJoon Cho
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
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Xiang SF, Zhang XQ, Yang SJ, Gao YY, Gao BL, Shi QL, Li S. Intravoxel Incoherent Motion Magnetic Resonance Imaging with Integrated Slice-specific Shimming for old myocardial infarction: A Pilot Study. Sci Rep 2019; 9:19766. [PMID: 31875029 PMCID: PMC6930276 DOI: 10.1038/s41598-019-56489-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 12/12/2019] [Indexed: 11/14/2022] Open
Abstract
Currently, little is known regarding the value of quantitative parameters derived from the intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) with integrated slice-specific shimming (iShim) sequence in detecting old myocardial infarction and myocardial fibrosis. This study was to investigate the value of IVIM-MRI with iShim sequence in diagnosing old myocardial infarction and fibrosis. Thirty-five patients with both old myocardial infarction and myocardial fibrosis and 12 healthy volunteers were prospectively enrolled to undergo cardiac diffusion-weighted imaging (DWI) using seven b-values (0, 20, 60, 80, 120, 200 and 600 s/mm2). The iShim sequence was used for IVIM data acquisition, and the diffusion parameters, D, D* and f values for IVIM, and conventional apparent diffusion coefficient (ADC) were evaluated on the anterior, posterior and lateral walls of the ventricular septum using the short axis of the heart. Significant differences were found in the D, D* and f values between healthy subjects and patients with old myocardial infarction and myocardial fibrosis (P = 0.000), with the median value of the D and f significantly smaller in the myocardial infarction and fibrosis than in the normal control but the median value of D* significantly greater in the myocardial infarction and fibrosis than in the normal control. In the receiver operating curve analysis, the areas under the curve were 0.939, 0.988 and 0.959 for the D, D* and f values, respectively. The sensitivities and specificities were 84.6% and 94.4% for D, 88.9% and 84.6% for D* and 100% and 93.1% for the f values, respectively. In conclusion, the IVIM-derived parameters (D, D* and f) obtained using the iShim DWI technique showed high capacity in diagnosing old myocardial infarction and myocardial fibrosis by providing diffusion and perfusion information, which may have great importance in future clinical practice.
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Affiliation(s)
- Shi-Feng Xiang
- Handan Central Hospital, 15 Southern Zhonghua Street, Handan City, Hebei Province, 056001, China
| | - Xue-Qiang Zhang
- Handan Central Hospital, 15 Southern Zhonghua Street, Handan City, Hebei Province, 056001, China.
| | - Su-Jun Yang
- Handan Central Hospital, 15 Southern Zhonghua Street, Handan City, Hebei Province, 056001, China
| | - Yun-Yun Gao
- Handan Central Hospital, 15 Southern Zhonghua Street, Handan City, Hebei Province, 056001, China
| | - Bu-Lang Gao
- Handan Central Hospital, 15 Southern Zhonghua Street, Handan City, Hebei Province, 056001, China
| | - Qing-Lei Shi
- Siemens medical system Co. Ltd., Beijing, 100176, China
| | - Shuai Li
- Siemens medical system Co. Ltd., Beijing, 100176, China
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Nielles-Vallespin S, Scott A, Ferreira P, Khalique Z, Pennell D, Firmin D. Cardiac Diffusion: Technique and Practical Applications. J Magn Reson Imaging 2019; 52:348-368. [PMID: 31482620 DOI: 10.1002/jmri.26912] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 12/12/2022] Open
Abstract
The 3D microarchitecture of the cardiac muscle underlies the mechanical and electrical properties of the heart. Cardiomyocytes are arranged helically through the depth of the wall, and their shortening leads to macroscopic torsion, twist, and shortening during cardiac contraction. Furthermore, cardiomyocytes are organized in sheetlets separated by shear layers, which reorientate, slip, and shear during macroscopic left ventricle (LV) wall thickening. Cardiac diffusion provides a means for noninvasive interrogation of the 3D microarchitecture of the myocardium. The fundamental principle of MR diffusion is that an MRI signal is attenuated by the self-diffusion of water in the presence of large diffusion-encoding gradients. Since water molecules are constrained by the boundaries in biological tissue (cell membranes, collagen layers, etc.), depicting their diffusion behavior elucidates the shape of the myocardial microarchitecture they are embedded in. Cardiac diffusion therefore provides a noninvasive means to understand not only the dynamic changes in cardiac microstructure of healthy myocardium during cardiac contraction but also the pathophysiological changes in the presence of disease. This unique and innovative technology offers tremendous potential to enable improved clinical diagnosis through novel microstructural and functional assessment. in vivo cardiac diffusion methods are immediately translatable to patients, opening new avenues for diagnostic investigation and treatment evaluation in a range of clinically important cardiac pathologies. This review article describes the 3D microstructure of the LV, explains in vivo and ex vivo cardiac MR diffusion acquisition and postprocessing techniques, as well as clinical applications to date. Level of Evidence: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019. J. Magn. Reson. Imaging 2020;52:348-368.
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Affiliation(s)
- Sonia Nielles-Vallespin
- Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, UK.,NHLI, Imperial College of Science, Technology and Medicine, London, UK
| | - Andrew Scott
- Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, UK.,NHLI, Imperial College of Science, Technology and Medicine, London, UK
| | - Pedro Ferreira
- Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, UK.,NHLI, Imperial College of Science, Technology and Medicine, London, UK
| | - Zohya Khalique
- Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, UK.,NHLI, Imperial College of Science, Technology and Medicine, London, UK
| | - Dudley Pennell
- Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, UK.,NHLI, Imperial College of Science, Technology and Medicine, London, UK
| | - David Firmin
- Cardiovascular MR Unit, Royal Brompton And Harefield NHS Foundation Trust, London, UK.,NHLI, Imperial College of Science, Technology and Medicine, London, UK
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Spinner GR, Stoeck CT, Mathez L, von Deuster C, Federau C, Kozerke S. On probing intravoxel incoherent motion in the heart‐spin‐echo versus stimulated‐echo DWI. Magn Reson Med 2019; 82:1150-1163. [DOI: 10.1002/mrm.27777] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 03/06/2019] [Accepted: 03/27/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Georg R. Spinner
- Institute for Biomedical Engineering University and ETH Zurich Zurich Switzerland
| | - Christian T. Stoeck
- Institute for Biomedical Engineering University and ETH Zurich Zurich Switzerland
| | - Linda Mathez
- Institute for Biomedical Engineering University and ETH Zurich Zurich Switzerland
| | | | - Christian Federau
- Institute for Biomedical Engineering University and ETH Zurich Zurich Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering University and ETH Zurich Zurich Switzerland
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11
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Xiang SF, Zhang XQ, Yang SJ, Hou B, Wang YF, Huo S, Dong XL, Yang Z. STROBE-A preliminary investigation of IVIM-DWI in cardiac imaging. Medicine (Baltimore) 2018; 97:e11902. [PMID: 30200075 PMCID: PMC6133472 DOI: 10.1097/md.0000000000011902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
This study aims to explore the possibility to apply intravoxel incoherent motion-magnetic resonance imaging (IVIM-MRI) in cardiac imaging.Multi-b-value diffusion-weighted imaging (DWI) sequence scanning was performed on 12 healthy volunteers. A double exponential model was adopted, and the b-value sequence was 0, 20, 60, 80, 120, 200, and 600 second/mm. The D-value, D*-value, and f-value of the anterior posterior and lateral walls of the ventricular septum were respectively measured on the short axis section of the heart, the parameters of the myocardium in different blood supply areas in each segment were recorded, and the measured data of these different segments were compared using analysis of variance.Among these 12 healthy volunteers, the D-value, D*-value, and f-value of these 72 segments were not exactly equal, the D-values of the myocardium in the 5th and 11th segment were lower than those in the 2nd, 3rd, 8th, and 9th segments, and the pairwise differences were statistically significant (P < .001). Furthermore, the difference in D-value between the 5th and 11th segments was not statistically significant (P = 1.000). The D*-value and f-value of the myocardium in the 5th and 11th segment were higher than those in the 2nd, 3rd, 8th, and 9th segments, and the pairwise differences were statistically significant (P < .001). Furthermore, the differences in D*-value and f-value between the 5th and 11th segments was not statistically significant (P = .214, .787).The intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) technique can quantitatively reflect the diffusion and blood perfusion status of the myocardium.
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Affiliation(s)
| | | | | | | | | | - Shuang Huo
- Department of Scientific Research, Handan Central Hospital, Handan, China
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12
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Slator PJ, Hutter J, McCabe L, Gomes ADS, Price AN, Panagiotaki E, Rutherford MA, Hajnal JV, Alexander DC. Placenta microstructure and microcirculation imaging with diffusion MRI. Magn Reson Med 2018; 80:756-766. [PMID: 29230859 PMCID: PMC5947291 DOI: 10.1002/mrm.27036] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 12/30/2022]
Abstract
PURPOSE To assess which microstructural models best explain the diffusion-weighted MRI signal in the human placenta. METHODS The placentas of nine healthy pregnant subjects were scanned with a multishell, multidirectional diffusion protocol at 3T. A range of multicompartment biophysical models were fit to the data, and ranked using the Bayesian information criterion. RESULTS Anisotropic extensions to the intravoxel incoherent motion model, which consider the effect of coherent orientation in both microvascular structure and tissue microstructure, consistently had the lowest Bayesian information criterion values. Model parameter maps and model selection results were consistent with the physiology of the placenta and surrounding tissue. CONCLUSION Anisotropic intravoxel incoherent motion models explain the placental diffusion signal better than apparent diffusion coefficient, intravoxel incoherent motion, and diffusion tensor models, in information theoretic terms, when using this protocol. Future work will aim to determine if model-derived parameters are sensitive to placental pathologies associated with disorders, such as fetal growth restriction and early-onset pre-eclampsia. Magn Reson Med 80:756-766, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Paddy J. Slator
- Centre for Medical Image Computing and Department of Computer ScienceUniversity College LondonLondonUK
| | - Jana Hutter
- Centre for the Developing Brain, King's College LondonLondonUK,Biomedical Engineering DepartmentKing's College LondonLondonUK
| | - Laura McCabe
- Centre for the Developing Brain, King's College LondonLondonUK
| | | | - Anthony N. Price
- Centre for the Developing Brain, King's College LondonLondonUK,Biomedical Engineering DepartmentKing's College LondonLondonUK
| | - Eleftheria Panagiotaki
- Centre for Medical Image Computing and Department of Computer ScienceUniversity College LondonLondonUK
| | | | - Joseph V. Hajnal
- Centre for the Developing Brain, King's College LondonLondonUK,Biomedical Engineering DepartmentKing's College LondonLondonUK
| | - Daniel C. Alexander
- Centre for Medical Image Computing and Department of Computer ScienceUniversity College LondonLondonUK
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13
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Kristensen TD, Mandl RC, Jepsen JR, Rostrup E, Glenthøj LB, Nordentoft M, Glenthøj BY, Ebdrup BH. Non-pharmacological modulation of cerebral white matter organization: A systematic review of non-psychiatric and psychiatric studies. Neurosci Biobehav Rev 2018; 88:84-97. [DOI: 10.1016/j.neubiorev.2018.03.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 03/11/2018] [Accepted: 03/12/2018] [Indexed: 10/17/2022]
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14
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Mozumder M, Beltrachini L, Collier Q, Pozo JM, Frangi AF. Simultaneous magnetic resonance diffusion and pseudo-diffusion tensor imaging. Magn Reson Med 2018; 79:2367-2378. [PMID: 28714249 PMCID: PMC5836966 DOI: 10.1002/mrm.26840] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/23/2017] [Accepted: 06/24/2017] [Indexed: 12/11/2022]
Abstract
PURPOSE An emerging topic in diffusion magnetic resonance is imaging blood microcirculation alongside water diffusion using the intravoxel incoherent motion (IVIM) model. Recently, a combined IVIM diffusion tensor imaging (IVIM-DTI) model was proposed, which accounts for both anisotropic pseudo-diffusion due to blood microcirculation and anisotropic diffusion due to tissue microstructures. In this article, we propose a robust IVIM-DTI approach for simultaneous diffusion and pseudo-diffusion tensor imaging. METHODS Conventional IVIM estimation methods can be broadly divided into two-step (diffusion and pseudo-diffusion estimated separately) and one-step (diffusion and pseudo-diffusion estimated simultaneously) methods. Here, both methods were applied on the IVIM-DTI model. An improved one-step method based on damped Gauss-Newton algorithm and a Gaussian prior for the model parameters was also introduced. The sensitivities of these methods to different parameter initializations were tested with realistic in silico simulations and experimental in vivo data. RESULTS The one-step damped Gauss-Newton method with a Gaussian prior was less sensitive to noise and the choice of initial parameters and delivered more accurate estimates of IVIM-DTI parameters compared to the other methods. CONCLUSION One-step estimation using damped Gauss-Newton and a Gaussian prior is a robust method for simultaneous diffusion and pseudo-diffusion tensor imaging using IVIM-DTI model. Magn Reson Med 79:2367-2378, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Meghdoot Mozumder
- Center for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)Department of Electronic and Electrical Engineering, The University of SheffieldSheffieldUK
| | - Leandro Beltrachini
- Center for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)Department of Electronic and Electrical Engineering, The University of SheffieldSheffieldUK
| | - Quinten Collier
- iMinds Vision LabDepartment of Physics, University of Antwerp (CDE)AntwerpenBelgium
| | - Jose M. Pozo
- Center for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)Department of Electronic and Electrical Engineering, The University of SheffieldSheffieldUK
| | - Alejandro F. Frangi
- Center for Computational Imaging & Simulation Technologies in Biomedicine (CISTIB)Department of Electronic and Electrical Engineering, The University of SheffieldSheffieldUK
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15
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Stoeck CT, von Deuster C, Fleischmann T, Lipiski M, Cesarovic N, Kozerke S. Direct comparison of in vivo versus postmortem second‐order motion‐compensated cardiac diffusion tensor imaging. Magn Reson Med 2017; 79:2265-2276. [DOI: 10.1002/mrm.26871] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 07/21/2017] [Accepted: 07/25/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Christian T. Stoeck
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich Switzerland
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonLondon United Kingdom
| | - Constantin von Deuster
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich Switzerland
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonLondon United Kingdom
| | - Thea Fleischmann
- Division of Surgical ResearchUniversity Hospital Zurich, University of ZurichZurich Switzerland
| | - Miriam Lipiski
- Division of Surgical ResearchUniversity Hospital Zurich, University of ZurichZurich Switzerland
| | - Nikola Cesarovic
- Division of Surgical ResearchUniversity Hospital Zurich, University of ZurichZurich Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurich Switzerland
- Division of Imaging Sciences and Biomedical EngineeringKing's College LondonLondon United Kingdom
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16
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Rydhög AS, Szczepankiewicz F, Wirestam R, Ahlgren A, Westin CF, Knutsson L, Pasternak O. Separating blood and water: Perfusion and free water elimination from diffusion MRI in the human brain. Neuroimage 2017; 156:423-434. [PMID: 28412443 PMCID: PMC5548601 DOI: 10.1016/j.neuroimage.2017.04.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 04/07/2017] [Accepted: 04/08/2017] [Indexed: 12/21/2022] Open
Abstract
The assessment of the free water fraction in the brain provides important information about extracellular processes such as atrophy and neuroinflammation in various clinical conditions as well as in normal development and aging. Free water estimates from diffusion MRI are assumed to account for freely diffusing water molecules in the extracellular space, but may be biased by other pools of molecules in rapid random motion, such as the intravoxel incoherent motion (IVIM) of blood, where water molecules perfuse in the randomly oriented capillary network. The goal of this work was to separate the signal contribution of the perfusing blood from that of free-water and of other brain diffusivities. The influence of the vascular compartment on the estimation of the free water fraction and other diffusivities was investigated by simulating perfusion in diffusion MRI data. The perfusion effect in the simulations was significant, especially for the estimation of the free water fraction, and was maintained as long as low b-value data were included in the analysis. Two approaches to reduce the perfusion effect were explored in this study: (i) increasing the minimal b-value used in the fitting, and (ii) using a three-compartment model that explicitly accounts for water molecules in the capillary blood. Estimation of the model parameters while excluding low b-values reduced the perfusion effect but was highly sensitive to noise. The three-compartment model fit was more stable and additionally, provided an estimation of the volume fraction of the capillary blood compartment. The three-compartment model thus disentangles the effects of free water diffusion and perfusion, which is of major clinical importance since changes in these components in the brain may indicate different pathologies, i.e., those originating from the extracellular space, such as neuroinflammation and atrophy, and those related to the vascular space, such as vasodilation, vasoconstriction and capillary density. Diffusion MRI data acquired from a healthy volunteer, using multiple b-shells, demonstrated an expected non-zero contribution from the blood fraction, and indicated that not accounting for the perfusion effect may explain the overestimation of the free water fraction evinced in previous studies. Finally, the applicability of the method was demonstrated with a dataset acquired using a clinically feasible protocol with shorter acquisition time and fewer b-shells.
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Affiliation(s)
- Anna S Rydhög
- Department of Medical Radiation Physics, Lund University, Barngatan 2B, SE-221 85 Lund, Sweden.
| | - Filip Szczepankiewicz
- Department of Medical Radiation Physics, Lund University, Barngatan 2B, SE-221 85 Lund, Sweden.
| | - Ronnie Wirestam
- Department of Medical Radiation Physics, Lund University, Barngatan 2B, SE-221 85 Lund, Sweden.
| | - André Ahlgren
- Department of Medical Radiation Physics, Lund University, Barngatan 2B, SE-221 85 Lund, Sweden.
| | - Carl-Fredrik Westin
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston St, Boston, MA 02215, USA.
| | - Linda Knutsson
- Department of Medical Radiation Physics, Lund University, Barngatan 2B, SE-221 85 Lund, Sweden; The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, 600 N. Wolf Street, Park 311, Baltimore, MD 21287, USA.
| | - Ofer Pasternak
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston St, Boston, MA 02215, USA; Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston St, Boston, MA 02215, USA.
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17
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Wells JA, Thomas DL, Saga T, Kershaw J, Aoki I. MRI of cerebral micro-vascular flow patterns: A multi-direction diffusion-weighted ASL approach. J Cereb Blood Flow Metab 2017; 37:2076-2083. [PMID: 27461904 PMCID: PMC5464702 DOI: 10.1177/0271678x16660985] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study and clinical assessment of brain disease is currently hindered by a lack of non-invasive methods for the detailed and accurate evaluation of cerebral vascular pathology. Angiography can detect aberrant flow in larger feeding arteries/arterioles but cannot resolve the micro-vascular network. Small vessels are a key site of vascular pathology that can lead to haemorrhage and infarction, which may in turn trigger or exacerbate neurodegenerative processes. In this study, we describe a method to investigate microvascular flow anisotropy using a hybrid arterial spin labelling and multi-direction diffusion-weighted MRI sequence. We present evidence that the technique is sensitive to the mean/predominant direction of microvascular flow in localised regions of the rat cortex. The data provide proof of principle for a novel and non-invasive imaging tool to investigate cerebral micro-vascular flow patterns in healthy and disease states.
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Affiliation(s)
- J A Wells
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan.,2 UCL Centre for Advanced Biomedical Imaging, University College London, London, UK
| | - D L Thomas
- 3 Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, UK.,4 Leonard Wolfson Experimental Neurology Centre, UCL Institute of Neurology, London, UK
| | - T Saga
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - J Kershaw
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - I Aoki
- 1 National Institute of Radiological Sciences (NIRS), National Institute for Quantum and Radiological Science and Technology (QST), Chiba, Japan
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18
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Hilbert F, Bock M, Neubauer H, Veldhoen S, Wech T, Bley TA, Köstler H. An intravoxel oriented flow model for diffusion-weighted imaging of the kidney. NMR IN BIOMEDICINE 2016; 29:1403-1413. [PMID: 27488570 DOI: 10.1002/nbm.3584] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 06/06/2016] [Accepted: 06/21/2016] [Indexed: 06/06/2023]
Abstract
By combining intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) we introduce a new diffusion model called intravoxel oriented flow (IVOF) that accounts for anisotropy of diffusion and the flow-related signal. An IVOF model using a simplified apparent flow fraction tensor (IVOFf ) is applied to diffusion-weighted imaging of human kidneys. The kidneys of 13 healthy volunteers were examined on a 3 T scanner. Diffusion-weighted images were acquired with six b values between 0 and 800 s/mm(2) and 30 diffusion directions. Diffusivity and flow fraction were calculated for different diffusion models. The Akaike information criterion was used to compare the model fit of the proposed IVOFf model to IVIM and DTI. In the majority of voxels the proposed IVOFf model with a simplified apparent flow fraction tensor performs better than IVIM and DTI. Mean diffusivity is significantly higher in DTI compared with models that account for the flow-related signal. The fractional anisotropy of diffusion is significantly reduced when flow fraction is considered to be anisotropic. Anisotropy of the apparent flow fraction tensor is significantly higher in the renal medulla than in the cortex region. The IVOFf model describes diffusion-weighted data in the human kidney more accurately than IVIM or DTI. The apparent flow fraction in the kidney proved to be anisotropic.
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Affiliation(s)
- Fabian Hilbert
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany.
| | - Maximilian Bock
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Henning Neubauer
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Simon Veldhoen
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Tobias Wech
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Thorsten Alexander Bley
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
| | - Herbert Köstler
- Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany
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19
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Abdullah OM, Seidel T, Dahl M, Gomez AD, Yiep G, Cortino J, Sachse FB, Albertine KH, Hsu EW. Diffusion tensor imaging and histology of developing hearts. NMR IN BIOMEDICINE 2016; 29:1338-1349. [PMID: 27485033 PMCID: PMC5160010 DOI: 10.1002/nbm.3576] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 05/24/2016] [Accepted: 06/03/2016] [Indexed: 06/06/2023]
Abstract
Diffusion tensor imaging (DTI) has emerged as a promising method for noninvasive quantification of myocardial microstructure. However, the origin and behavior of DTI measurements during myocardial normal development and remodeling remain poorly understood. In this work, conventional and bicompartmental DTI in addition to three-dimensional histological correlation were performed in a sheep model of myocardial development from third trimester to postnatal 5 months of age. Comparing the earliest time points in the third trimester with the postnatal 5 month group, the scalar transverse diffusivities preferentially increased in both left ventricle (LV) and right ventricle (RV): secondary eigenvalues D2 increased by 54% (LV) and 36% (RV), whereas tertiary eigenvalues D3 increased by 85% (LV) and 67% (RV). The longitudinal diffusivity D1 changes were small, which led to a decrease in fractional anisotropy by 41% (LV) and 33% (RV) in 5 month versus fetal hearts. Histological analysis suggested that myocardial development is associated with hyperplasia in the early stages of the third trimester followed by myocyte growth in the later stages up to 5 months of age (increased average myocyte width by 198%, myocyte length by 128%, and decreased nucleus density by 70% between preterm and postnatal 5 month hearts.) In a few histological samples (N = 6), correlations were observed between DTI longitudinal diffusivity and myocyte length (r = 0.86, P < 0.05), and transverse diffusivity and myocyte width (r = 0.96, P < 0.01). Linear regression analysis showed that transverse diffusivities are more affected by changes in myocyte size and nucleus density changes than longitudinal diffusivities, which is consistent with predictions of classical models of diffusion in porous media. Furthermore, primary and secondary DTI eigenvectors during development changed significantly. Collectively, the findings demonstrate a role for DTI to monitor and quantify myocardial development, and potentially cardiac disease. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Osama M Abdullah
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA.
| | - Thomas Seidel
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
| | - MarJanna Dahl
- Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Arnold David Gomez
- Department of Electrical Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Gavin Yiep
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
| | - Julia Cortino
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
| | - Frank B Sachse
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
| | - Kurt H Albertine
- Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Edward W Hsu
- Department of Bioengineering, University of Utah, Salt Lake City, UT, USA
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20
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McClymont D, Teh I, Carruth E, Omens J, McCulloch A, Whittington HJ, Kohl P, Grau V, Schneider JE. Evaluation of non-Gaussian diffusion in cardiac MRI. Magn Reson Med 2016; 78:1174-1186. [PMID: 27670633 PMCID: PMC5366286 DOI: 10.1002/mrm.26466] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/18/2016] [Accepted: 08/23/2016] [Indexed: 12/20/2022]
Abstract
PURPOSE The diffusion tensor model assumes Gaussian diffusion and is widely applied in cardiac diffusion MRI. However, diffusion in biological tissue deviates from a Gaussian profile as a result of hindrance and restriction from cell and tissue microstructure, and may be quantified better by non-Gaussian modeling. The aim of this study was to investigate non-Gaussian diffusion in healthy and hypertrophic hearts. METHODS Thirteen rat hearts (five healthy, four sham, four hypertrophic) were imaged ex vivo. Diffusion-weighted images were acquired at b-values up to 10,000 s/mm2 . Models of diffusion were fit to the data and ranked based on the Akaike information criterion. RESULTS The diffusion tensor was ranked best at b-values up to 2000 s/mm2 but reflected the signal poorly in the high b-value regime, in which the best model was a non-Gaussian "beta distribution" model. Although there was considerable overlap in apparent diffusivities between the healthy, sham, and hypertrophic hearts, diffusion kurtosis and skewness in the hypertrophic hearts were more than 20% higher in the sheetlet and sheetlet-normal directions. CONCLUSION Non-Gaussian diffusion models have a higher sensitivity for the detection of hypertrophy compared with the Gaussian model. In particular, diffusion kurtosis may serve as a useful biomarker for characterization of disease and remodeling in the heart. Magn Reson Med 78:1174-1186, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Darryl McClymont
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Irvin Teh
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Eric Carruth
- Department of Bioengineering, University of California-San Diego, La Jolla, California, USA
| | - Jeffrey Omens
- Department of Bioengineering, University of California-San Diego, La Jolla, California, USA.,Department of Medicine, University of California-San Diego, La Jolla, California, USA
| | - Andrew McCulloch
- Department of Bioengineering, University of California-San Diego, La Jolla, California, USA
| | - Hannah J Whittington
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Peter Kohl
- National Heart and Lung Institute, Imperial College London, London, United Kingdom.,Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg, Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Vicente Grau
- Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Jürgen E Schneider
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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