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Co M, Raterman B, Klamer B, Kolipaka A, Walter B. Nucleus pulposus structure and function assessed in shear using magnetic resonance elastography, quantitative MRI, and rheometry. JOR Spine 2024; 7:e1335. [PMID: 38741919 PMCID: PMC11089841 DOI: 10.1002/jsp2.1335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 04/04/2024] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Background In vivo quantification of the structure-function relationship of the intervertebral disc (IVD) via quantitative MRI has the potential to aid objective stratification of disease and evaluation of restorative therapies. Magnetic resonance elastography (MRE) is an imaging technique that assesses tissue shear properties and combined with quantitative MRI metrics reflective of composition can inform structure-function of the IVD. The objectives of this study were to (1) compare MRE- and rheometry-derived shear modulus in agarose gels and nucleus pulposus (NP) tissue and (2) correlate MRE and rheological measures of NP tissue with composition and quantitative MRI. Method MRE and MRI assessment (i.e., T1ρ and T2 mapping) of agarose samples (2%, 3%, and 4% (w/v); n = 3-4/%) and of bovine caudal IVDs after equilibrium dialysis in 5% or 25% PEG (n = 13/PEG%) was conducted. Subsequently, agarose and NP tissue underwent torsional mechanical testing consisting of a frequency sweep from 1 to 100 Hz at a rotational strain of 0.05%. NP tissue was additionally evaluated under creep and stress relaxation conditions. Linear mixed-effects models and univariate regression analyses evaluated the effects of testing method, %agarose or %PEG, and frequency, as well as correlations between parameters. Results MRE- and rheometry-derived shear moduli were greater at 100 Hz than at 80 Hz in all agarose and NP tissue samples. Additionally, all samples with lower water content had higher complex shear moduli. There was a significant correlation between MRE- and rheometry-derived modulus values for homogenous agarose samples. T1ρ and T2 relaxation times for agarose and tissue were negatively correlated with complex shear modulus derived from both techniques. For NP tissue, shear modulus was positively correlated with GAG/wet-weight and negatively correlated with %water content. Conclusion This work demonstrates that MRE can assess hydration-induced changes in IVD shear properties and further highlights the structure-function relationship between composition and shear mechanical behaviors of NP tissue.
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Affiliation(s)
- Megan Co
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Brian Raterman
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Brett Klamer
- Department of Biomedical Informatics, Center for BiostatisticsThe Ohio State UniversityColumbusOhioUSA
| | - Arunark Kolipaka
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Benjamin Walter
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
- Department of OrthopaedicsThe Ohio State University Wexner Medical CenterColumbusOhioUSA
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Cho Y, Fakhouri F, Ballinger MN, Englert JA, Hayes D, Kolipaka A, Ghadiali SN. Magnetic Resonance Elastography and Computational Modeling Identify Heterogeneous Lung Biomechanical Properties during Cystic Fibrosis. Res Sq 2024:rs.3.rs-4125891. [PMID: 38562870 PMCID: PMC10984019 DOI: 10.21203/rs.3.rs-4125891/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The lung is a dynamic mechanical organ and several pulmonary disorders are characterized by heterogeneous changes in the lung's local mechanical properties (i.e. stiffness). These alterations lead to abnormal lung tissue deformation (i.e. strain) which have been shown to promote disease progression. Although heterogenous mechanical properties may be important biomarkers of disease, there is currently no non-invasive way to measure these properties for clinical diagnostic purposes. In this study, we use a magnetic resonance elastography technique to measure heterogenous distributions of the lung's shear stiffness in healthy adults and in people with Cystic Fibrosis. Additionally, computational finite element models which directly incorporate the measured heterogenous mechanical properties were developed to assess the effects on lung tissue deformation. Results indicate that consolidated lung regions in people with Cystic Fibrosis exhibited increased shear stiffness and reduced spatial heterogeneity compared to surrounding non-consolidated regions. Accounting for heterogenous lung stiffness in healthy adults did not change the globally averaged strain magnitude obtained in computational models. However, computational models that used heterogenous stiffness measurements predicted significantly more variability in local strain and higher spatial strain gradients. Finally, computational models predicted lower strain variability and spatial strain gradients in consolidated lung regions compared to non-consolidated regions. These results indicate that spatial variability in shear stiffness alters local strain and strain gradient magnitudes in people with Cystic Fibrosis. This imaged-based modeling technique therefore represents a clinically viable way to non-invasively assess lung mechanics during both health and disease.
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Affiliation(s)
| | | | | | | | - Don Hayes
- Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine
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Co M, Pack C, Osborn-King Z, Raterman B, Kolipaka A, Bentil SA, Walter BA. Modeling the effects of hydration on viscoelastic properties of nucleus pulposus tissue in shear using the fractional Zener model. J Biomech 2024; 164:111965. [PMID: 38354514 PMCID: PMC11097896 DOI: 10.1016/j.jbiomech.2024.111965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/16/2024]
Abstract
Nucleus pulposus (NP) tissue in the intervertebral disc (IVD) is a viscoelastic material exhibiting both solid- and fluid-like mechanical behaviors. Advances in viscoelastic models incorporating fractional calculus, such as the Fractional Zener (FZ) model, have potential to describe viscoelastic behaviors. The objectives of this study were to determine whether the FZ model can accurately describe the shear viscoelastic properties of NP tissue and determine if the fractional order (α) is related to tissue hydration. 30 caudal IVDs underwent equilibrium dialysis in 5% or 25% polyethylene glycol solutions to alter tissue hydration. Excised NP tissue underwent stress relaxation testing in shear and unconfined compression. Stress relaxation data was fitted to the FZ model to obtain viscoelastic properties. In both loading modes, the initial modulus was greater for the less hydrated 25% equilibrated samples compared to 5% with no change in the equilibrium modulus. Samples with lower water content (25% samples) had shorter relaxation times in shear and longer time constants in compression, highlighting the different interactions between the fluid and solid matrix in loading modes. Samples with lower water content had α values closer to 0, indicating that less hydrated samples behaved more solid-like on the viscoelastic spectrum. Tissue hydration correlated with α values for 25% samples in shear. This study demonstrates that the FZ model may be used to describe IVD tissue behavior under both loading modes; however, the greatest utility of the FZ model is in describing flow-independent shear behaviors, and α may inform tissue hydration in shear.
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Affiliation(s)
- Megan Co
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Chelsea Pack
- Department of Biomedical Engineering, West Virginia University, Morgantown, WV, United States
| | - Zachary Osborn-King
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States; Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Sarah A Bentil
- Department of Mechanical Engineering, Iowa State University, Ames, IA, United States
| | - Benjamin A Walter
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States; Department of Orthopaedics, The Ohio State University Wexner Medical Center, Columbus, OH, United States.
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Fakhouri FS, Joseph M, Ballinger M, Shukla V, Weimar D, Novak C, Ghadiali S, Kolipaka A. Magnetic Resonance Elastography (MRE) of Bleomycin-Induced Pulmonary Fibrosis in an Animal Model. Invest Radiol 2023; 58:299-306. [PMID: 36730906 PMCID: PMC10023269 DOI: 10.1097/rli.0000000000000935] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Idiopathic pulmonary fibrosis is responsible for 40,000 deaths annually in the United States. A hallmark of idiopathic pulmonary fibrosis is elevated collagen deposition, which alters lung stiffness. Clinically relevant ways to measure changes in lung stiffness during pulmonary fibrosis are not available, and new noninvasive imaging methods are needed to measure changes in lung mechanical properties. OBJECTIVES Magnetic resonance elastography (MRE) is an in vivo magnetic resonance imaging technique proven to detect changes in shear stiffness in different organs. This study used MRE, histology, and bronchoalveolar lavage (BAL) to study changes in the mechanical and structural properties of the lungs after bleomycin-induced pulmonary fibrosis in pigs. MATERIALS AND METHODS Pulmonary fibrosis was induced in 9 Yorkshire pigs by intratracheal instillation of 2 doses of bleomycin into the right lung only. Magnetic resonance elastography scans were performed at baseline and week 4 and week 8 postsurgery in a 1.5 T magnetic resonance imaging scanner using a spin-echo echo planar imaging sequence to measure changes in lung shear stiffness. At the time of each scan, a BAL was performed. After the final scan, whole lung tissue was removed and analyzed for histological changes. RESULTS Mean MRE-derived stiffness measurements at baseline, week 4, and week 8 for the control (left) lungs were 1.02 ± 0.27 kPa, 0.86 ± 0.29 kPa, and 0.68 ± 0.20 kPa, respectively. The ratio of the shear stiffness in the injured (right) lung to the uninjured control (left) lung at baseline, week 4, and week 8 was 0.98 ± 0.23, 1.52 ± 0.41, and 1.64 ± 0.40, respectively. High-dose animals showed increased protein in BAL fluid, elevated inflammation observed by the presence of patchy filtrates, and enhanced collagen and α-smooth muscle actin staining on histological sections. Low-dose animals and the control (left) lungs of high-dose animals did not show significant histopathological changes. CONCLUSION This study demonstrated that MRE can be used to detect changes in lung stiffness in pigs after bleomycin challenge.
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Affiliation(s)
- Faisal S. Fakhouri
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Technology, King Saud University, Riyadh, 12372, KSA
| | - Matthew Joseph
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, 43210, USA
| | - Megan Ballinger
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, 43210, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Vasudha Shukla
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - David Weimar
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, 43210, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Caymen Novak
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, 43210, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Samir Ghadiali
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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Co M, Dong H, Boulter DJ, Nguyen XV, Khan SN, Raterman B, Klamer B, Kolipaka A, Walter BA. Magnetic Resonance Elastography of Intervertebral Discs: Spin-Echo Echo-Planar Imaging Sequence Validation. J Magn Reson Imaging 2022; 56:1722-1732. [PMID: 35289470 PMCID: PMC9475395 DOI: 10.1002/jmri.28151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Magnetic resonance elastography (MRE) is an imaging technique that can noninvasively assess the shear properties of the intervertebral disc (IVD). Unlike the standard gradient recalled echo (GRE) MRE technique, a spin-echo echo-planar imaging (SE-EPI) sequence has the potential to improve imaging efficiency and patient compliance. PURPOSE To validate the use of an SE-EPI sequence for MRE of the IVD compared against the standard GRE sequence. STUDY TYPE Cross-over. SUBJECTS Twenty-eight healthy volunteers (15 males and 13 females, age range: 19-55). FIELD STRENGTH/SEQUENCE 3 T; GRE, SE-EPI with breath holds (SE-EPI-BH) and SE-EPI with free breathing (SE-EPI-FB) MRE sequences. ASSESSMENT MRE-derived shear stiffnesses were calculated via principal frequency analysis. SE-EPI derived shear stiffness and octahedral shear strain signal-to-noise ratios (OSS-SNR) were compared against those derived using the GRE sequence. The reproducibility and repeatability of SE-EPI stiffness measurements were determined. Shear stiffness was evaluated in the nucleus pulposus (NP) and annulus fibrosus (AF) regions of the disc. Scan times between sequences were compared. STATISTICAL TESTS Linear mixed models, Bland-Altman plots, and Lin's concordance correlation coefficients (CCCs) were used with P < 0.05 considered statistically significant. RESULTS Good correlation was observed between shear stiffnesses derived from the SE-EPI sequences with those derived from the GRE sequence with CCC values greater than 0.73 and 0.78 for the NP and AF regions, respectively. OSS-SNR was not significantly different between GRE and SE-EPI sequences (P > 0.05). SE-EPI sequences generated highly reproducible and repeatable stiffness measurements with CCC values greater than 0.97 in the NP and AF regions and reduced scan time by at least 51% compared to GRE. SE-EPI-BH and SE-EPI-FB stiffness measurements were similar with CCC values greater than 0.98 for both regions. DATA CONCLUSION SE-EPI-based MRE-derived stiffnesses were highly reproducible and repeatable and correlated with current standard GRE MRE-derived stiffness estimates while reducing scan times. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Megan Co
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Daniel J Boulter
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Xuan V Nguyen
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Safdar N Khan
- Department of Orthopedics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Brett Klamer
- Center for Biostatistics, The Ohio State University, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Benjamin A Walter
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
- Spine Research Institute, The Ohio State University, Columbus, Ohio, USA
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Dong H, Raterman B, White RD, Starr J, Vaccaro P, Haurani M, Go M, Eisner M, Brock G, Kolipaka A. MR Elastography of Abdominal Aortic Aneurysms: Relationship to Aneurysm Events. Radiology 2022; 304:721-729. [PMID: 35638926 PMCID: PMC9434816 DOI: 10.1148/radiol.212323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 03/26/2022] [Accepted: 04/07/2022] [Indexed: 11/11/2022]
Abstract
Background Abdominal aortic aneurysm (AAA) diameter remains the standard clinical parameter to predict growth and rupture. Studies suggest that using solely AAA diameter for risk stratification is insufficient. Purpose To evaluate the use of aortic MR elastography (MRE)-derived AAA stiffness and stiffness ratio at baseline to identify the potential for future aneurysm rupture or need for surgical repair. Materials and Methods Between August 2013 and March 2019, 72 participants with AAA and 56 healthy participants were enrolled in this prospective study. MRE examinations were performed to estimate AAA stiffness and the stiffness ratio between AAA and its adjacent remote normal aorta. Two Cox proportional hazards models were used to assess AAA stiffness and stiffness ratio for predicting aneurysmal events (subsequent repair, rupture, or diameter >5.0 cm). Log-rank tests were performed to determine a critical stiffness ratio suggesting high-risk AAAs. Baseline AAA stiffness and stiffness ratio were studied using Wilcoxon rank-sum tests between participants with and without aneurysmal events. Spearman correlation was used to investigate the relationship between stiffness and other potential imaging markers. Results Seventy-two participants with AAA (mean age, 71 years ± 9 [SD]; 56 men and 16 women) and 56 healthy participants (mean age, 42 years ± 16; 27 men and 29 women) were evaluated. In healthy participants, aortic stiffness positively correlated with age (ρ = 0.44; P < .001). AAA stiffness (event group [n = 21], 50.3 kPa ± 26.5 [SD]; no-event group [n = 21], 86.9 kPa ± 52.6; P = .01) and the stiffness ratio (event group, 0.7 ± 0.4; no-event group, 2.0 ± 1.4; P < .001) were lower in the event group than the no-event group at a mean follow-up of 449 days. AAA stiffness did not correlate with diameter in the event group (ρ = -0.06; P = .68) or the no-event group (ρ = -0.13; P = .32). AAA stiffness was inversely correlated with intraluminal thrombus area (ρ = -0.50; P = .01). Conclusion Lower abdominal aortic aneurysm stiffness and stiffness ratio measured with use of MR elastography was associated with aneurysmal events at a 15-month follow-up. © RSNA, 2022 See also the editorial by Sakuma in this issue.
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Affiliation(s)
- Huiming Dong
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Brian Raterman
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Richard D. White
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Jean Starr
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Patrick Vaccaro
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Mounir Haurani
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Michael Go
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Mariah Eisner
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Guy Brock
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
| | - Arunark Kolipaka
- From the Department of Radiology (H.D., B.R., R.D.W., A.K.), Department of Internal Medicine, Division of Cardiovascular Medicine (R.D.W., A.K.), Department of Surgery (J.S., P.V., M.H., M.G.), and Department of Biomedical Informatics and Center for Biostatistics (M.E., G.B.), College of Medicine, The Ohio State University Wexner Medical Center, 395 W 12th Ave, 4th Floor, Columbus, OH 43210; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio (H.D., A.K.); and Department of Radiology, Mayo Clinic, Jacksonville, Fla (R.D.W.)
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Cole R, Colombo E, Angelotti A, Kolipaka A, Ni A, Li N, Belury M. The Effects of Dietary Soybean Oil on Liver Fat and Visceral Adipose Tissue in Adults With Nonalcoholic Fatty Liver Disease: Study Protocol for a Randomized Control Trial. Curr Dev Nutr 2022. [DOI: 10.1093/cdn/nzac072.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Objectives
About 25% of adults in the United States have nonalcoholic fatty liver disease (NAFLD) which often accompanies abdominal obesity. Blood biomarkers of linoleic acid (LA), an essential omega-6 fatty acid, are inversely associated with visceral adipose tissue, liver fat, and the risk of NAFLD. To our knowledge, the effect of increasing dietary LA on ectopic fat in the liver and visceral adipose tissue in adults with NAFLD while maintaining weight has not been investigated. The objective of the Weight, Energy, Lipids and the Liver (WELL) study is to determine the impact of dietary LA-rich soybean oil on ectopic liver fat and visceral adipose tissue in adults with NAFLD.
Methods
In this 16-week parallel arm randomized control trial, 58 adults with NAFLD will be randomly assigned to consume 3 study foods per day made with either 10g of soybean oil each or 10g of palm oil each (30g of oil per day). Prior to randomization, participants will complete a 2-week run-in period to become acclimated by consuming 3 study foods per day, each delivering 10 g of an oil mixture (safflower oil and shortening in a 3.4:1 ratio). Participants will receive counseling from a registered dietitian to incorporate the study foods into their diets while maintaining their body weight. Self-reported study food consumption will be collected daily. Body weight will be measured every two weeks. Dietary intake and physical activity will be assessed through 24 hour recalls. Fasting blood will be collected every two weeks to measure fatty acids, cholesterol, triglycerides and markers of inflammation and glycemia. Magnetic Resonance Imaging (MRI) will be used to assess liver and visceral fat before and after the 16-week randomized intervention period. Additionally, postprandial cholesterol, triglycerides and markers of inflammation and glycemia will be measured before and after the randomized intervention period.
Results
We hypothesize that consumption of the study foods made with LA-rich soybean oil (30g/day) will result in a reduction in hepatic ectopic fat and visceral adipose tissue, without altering body weight.
Conclusions
Reducing liver fat and visceral adipose tissue through consumption of a LA-rich soybean oil may ultimately lead to improved cardiometabolic outcomes for adults with NAFLD.
Funding Sources
The United Soybean Board.
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Affiliation(s)
| | | | | | | | - Ai Ni
- The Ohio State University
| | - Na Li
- The Ohio State University
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Meyer T, Marticorena Garcia S, Tzschätzsch H, Herthum H, Shahryari M, Stencel L, Braun J, Kalra P, Kolipaka A, Sack I. Comparison of inversion methods in MR elastography: An open-access pipeline for processing multifrequency shear-wave data and demonstration in a phantom, human kidneys, and brain. Magn Reson Med 2022; 88:1840-1850. [PMID: 35691940 DOI: 10.1002/mrm.29320] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/22/2022] [Accepted: 05/11/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE Magnetic resonance elastography (MRE) maps the viscoelastic properties of soft tissues for diagnostic purposes. However, different MRE inversion methods yield different results, which hinder comparison of values, standardization, and establishment of quantitative MRE markers. Here, we introduce an expandable, open-access, webserver-based platform that offers multiple inversion techniques for multifrequency, 3D MRE data. METHODS The platform comprises a data repository and standard MRE inversion methods including local frequency estimation (LFE), direct-inversion based multifrequency dual elasto-visco (MDEV) inversion, and wavenumber-based (k-) MDEV. The use of the platform is demonstrated in phantom data and in vivo multifrequency MRE data of the kidneys and brains of healthy volunteers. RESULTS Detailed maps of stiffness were generated by all inversion methods showing similar detail of anatomy. Specifically, the inner renal cortex had higher shear wave speed (SWS) than renal medulla and outer cortex without lateral differences. k-MDEV yielded higher SWS values than MDEV or LFE (full kidney/brain k-MDEV: 2.71 ± 0.19/1.45 ± 0.14 m/s, MDEV: 2.14 ± 0.16/0.99 ± 0.11 m/s, LFE: 2.12 ± 0.15/0.89 ± 0.06 m/s). CONCLUSION The freely accessible platform supports the comparison of MRE results obtained with different inversion methods, filter thresholds, or excitation frequencies, promoting reproducibility in MRE across community-developed methods.
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Affiliation(s)
- Tom Meyer
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Heiko Tzschätzsch
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Helge Herthum
- Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Mehrgan Shahryari
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Lisa Stencel
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jürgen Braun
- Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Prateek Kalra
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Ingolf Sack
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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9
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Teh I, Romero R. WA, Boyle J, Coll‐Font J, Dall'Armellina E, Ennis DB, Ferreira PF, Kalra P, Kolipaka A, Kozerke S, Lohr D, Mongeon F, Moulin K, Nguyen C, Nielles‐Vallespin S, Raterman B, Schreiber LM, Scott AD, Sosnovik DE, Stoeck CT, Tous C, Tunnicliffe EM, Weng AM, Croisille P, Viallon M, Schneider JE. Validation of cardiac diffusion tensor imaging sequences: A multicentre test-retest phantom study. NMR Biomed 2022; 35:e4685. [PMID: 34967060 PMCID: PMC9285553 DOI: 10.1002/nbm.4685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/19/2021] [Accepted: 12/24/2021] [Indexed: 05/23/2023]
Abstract
Cardiac diffusion tensor imaging (DTI) is an emerging technique for the in vivo characterisation of myocardial microstructure, and there is a growing need for its validation and standardisation. We sought to establish the accuracy, precision, repeatability and reproducibility of state-of-the-art pulse sequences for cardiac DTI among 10 centres internationally. Phantoms comprising 0%-20% polyvinylpyrrolidone (PVP) were scanned with DTI using a product pulsed gradient spin echo (PGSE; N = 10 sites) sequence, and a custom motion-compensated spin echo (SE; N = 5) or stimulated echo acquisition mode (STEAM; N = 5) sequence suitable for cardiac DTI in vivo. A second identical scan was performed 1-9 days later, and the data were analysed centrally. The average mean diffusivities (MDs) in 0% PVP were (1.124, 1.130, 1.113) x 10-3 mm2 /s for PGSE, SE and STEAM, respectively, and accurate to within 1.5% of reference data from the literature. The coefficients of variation in MDs across sites were 2.6%, 3.1% and 2.1% for PGSE, SE and STEAM, respectively, and were similar to previous studies using only PGSE. Reproducibility in MD was excellent, with mean differences in PGSE, SE and STEAM of (0.3 ± 2.3, 0.24 ± 0.95, 0.52 ± 0.58) x 10-5 mm2 /s (mean ± 1.96 SD). We show that custom sequences for cardiac DTI provide accurate, precise, repeatable and reproducible measurements. Further work in anisotropic and/or deforming phantoms is warranted.
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Affiliation(s)
- Irvin Teh
- Leeds Institute of Cardiovascular and Metabolic MedicineUniversity of LeedsLeedsUK
| | - William A. Romero R.
- Univ Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1UJM‐Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1294, F‐42023Saint EtienneFrance
| | - Jordan Boyle
- School of Mechanical EngineeringUniversity of LeedsLeedsUK
| | - Jaume Coll‐Font
- Cardiovascular Research Center and A. A. Martinos Center for Biomedical ImagingMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Erica Dall'Armellina
- Leeds Institute of Cardiovascular and Metabolic MedicineUniversity of LeedsLeedsUK
| | - Daniel B. Ennis
- Division of RadiologyVA Palo Alto Health Care SystemPalo AltoCaliforniaUSA
- Department of RadiologyStanford UniversityStanfordCaliforniaUSA
| | - Pedro F. Ferreira
- Cardiovascular Magnetic Resonance UnitThe Royal Brompton and Harefield NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Prateek Kalra
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Arunark Kolipaka
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Sebastian Kozerke
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurichSwitzerland
| | - David Lohr
- Department of Cardiovascular ImagingComprehensive Heart Failure CenterWürzburgGermany
| | | | - Kévin Moulin
- Department of RadiologyStanford UniversityStanfordCaliforniaUSA
| | - Christopher Nguyen
- Cardiovascular Research Center and A. A. Martinos Center for Biomedical ImagingMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Sonia Nielles‐Vallespin
- Cardiovascular Magnetic Resonance UnitThe Royal Brompton and Harefield NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Brian Raterman
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Laura M. Schreiber
- Department of Cardiovascular ImagingComprehensive Heart Failure CenterWürzburgGermany
| | - Andrew D. Scott
- Cardiovascular Magnetic Resonance UnitThe Royal Brompton and Harefield NHS Foundation TrustLondonUK
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - David E. Sosnovik
- Cardiovascular Research Center and A. A. Martinos Center for Biomedical ImagingMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Christian T. Stoeck
- Institute for Biomedical EngineeringUniversity and ETH ZurichZurichSwitzerland
| | - Cyril Tous
- Department of Radiology, Radiation‐Oncology and Nuclear Medicine and Institute of Biomedical EngineeringUniversité de MontréalMontréalCanada
| | - Elizabeth M. Tunnicliffe
- Radcliffe Department of MedicineUniversity of OxfordOxfordUK
- Oxford NIHR Biomedical Research CentreOxfordUK
| | - Andreas M. Weng
- Department of Diagnostic and Interventional RadiologyUniversity Hospital WürzburgWürzburgGermany
| | - Pierre Croisille
- Univ Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1UJM‐Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1294, F‐42023Saint EtienneFrance
| | - Magalie Viallon
- Univ Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1UJM‐Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1294, F‐42023Saint EtienneFrance
| | - Jürgen E. Schneider
- Leeds Institute of Cardiovascular and Metabolic MedicineUniversity of LeedsLeedsUK
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10
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Fakhouri F, Kannengiesser S, Pfeuffer J, Gokun Y, Kolipaka A. Free-breathing MR elastography of the lungs: An in vivo study. Magn Reson Med 2022; 87:236-248. [PMID: 34463400 PMCID: PMC8616792 DOI: 10.1002/mrm.28986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 01/03/2023]
Abstract
PURPOSE Lung stiffness alters with many diseases; therefore, several MR elastography (MRE) studies were performed earlier to investigate the stiffness of the right lung during breathhold at residual volume and total lung capacity. The aims of this study were 1) to estimate shear stiffness of the lungs using MRE under free breathing and demonstrate the measurements' repeatability and reproducibility, and 2) to compare lung stiffness under free breathing to breathhold and as a function of age and gender. METHODS Twenty-five healthy volunteers were scanned on a 1.5 Tesla MRI scanner. Spin-echo dual-density spiral and a spin-echo EPI MRE sequences were used to measure shear stiffness of the lungs during free breathing and breathhold at midpoint of tidal volume, respectively. Concordance correlation coefficient and Bland-Altman analyses were performed to determine the repeatability and reproducibility of the spin-echo dual-density spiral-derived shear stiffness. Repeated measures analyses of variances were used to investigate differences in shear stiffness between spin-echo dual-density spiral and spin-echo EPI, right and left lungs, males and females, and different age groups. RESULTS Free-breathing MRE sequence was highly repeatable and reproducible (concordance correlation coefficient > 0.86 for both lungs). Lung stiffness was significantly lower in breathhold than in free breathing (P < .001), which can be attributed to potential stress relaxation of lung parenchyma or breathhold inconsistencies. However, there was no significant difference between different age groups (P = .08). The left lung showed slightly higher stiffness values than the right lung (P = .14). There is no significant difference in lung stiffness between genders. CONCLUSION This study demonstrated the feasibility of free-breathing lung MRE with excellent repeatability and reproducibility. Stiffness changes with age and during the respiratory cycle. However, gender does not influence lungs stiffness.
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Affiliation(s)
- Faisal Fakhouri
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA.,Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | | | - Josef Pfeuffer
- MR Application Development, Siemens Healthcare GmbH, Erlangen, Germany
| | - Yevgeniya Gokun
- Department of Biomedical Informatics, Center for Biostatistics, The Ohio State University, Columbus, OH 43210, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA.,Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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11
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Abstract
Magnetic resonance elastography (MRE) is an emerging noninvasive technique, an alternative to palpation for quantitative assessment of biomechanical properties of tissue. In MRE, tissue stiffness information is obtained by a 3-step process, propagating mechanical waves in the tissues, measuring the wave propagation using modified magnetic resonance (MR) pulse sequences, and generating the quantitative stiffness maps from the MR images. MRE is clinically used in patients with liver diseases, whereas its applications in other organs are still being investigated. At present, the pediatric studies are in the initial stage and preliminary results promise to provide additional information about tissue characteristics.
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Affiliation(s)
- Manjunathan Nanjappa
- Department of Radiology, The Ohio State University Wexner Medical Center, 460 West 12th Avenue, Room No 333 3rd Floor, Columbus, OH 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State Wexner Medical Center, 395 West 12th Avenue, 4th Floor, Columbus, OH 43210, USA.
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12
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Dong H, Ahmad R, Miller R, Kolipaka A. MR elastography inversion by compressive recovery. Phys Med Biol 2021; 66. [PMID: 34261056 DOI: 10.1088/1361-6560/ac145a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 07/14/2021] [Indexed: 11/11/2022]
Abstract
Direct inversion (DI) derives tissue shear modulus by inverting the Helmholtz equation. However, conventional DI is sensitive to data quality due to the ill-posed nature of Helmholtz inversion and thus providing reliable stiffness estimation can be challenging. This becomes more problematic in the case of estimating shear stiffness of the lung in which the low tissue density and short T2* result in considerably low signal-to-noise ratio during lung MRE. In the present study, we propose to perform MRE inversion by compressive recovery (MICRo). Such a technique aims to improve the numerical stability and the robustness to data noise of Helmholtz inversion by using prior knowledge on data noise and transform sparsity of the stiffness map. The developed inversion strategy was first validated in simulated phantoms with known stiffness. Next, MICRo was compared to the standard clinical multi-modal DI (MMDI) method forin vivoliver MRE in healthy subjects and patients with different stages of liver fibrosis. After establishing the accuracy of MICRo, we demonstrated the robustness of the proposed technique against data noise in lung MRE with healthy subjects. In simulated phantoms with single-directional or multi-directional waves, MICRo outperformed DI with Romano filter or Savitsky and Golay filter, especially when the stiffness and/or noise level was high. In hepatic MRE application, agreement was observed between MICRo and MMDI. Measuringin vivolung stiffness, MICRo demonstrated its advantages over filtered DI by yielding stable stiffness estimation at both residual volume and total lung capacity. These preliminary results demonstrate the potential value of the proposed technique and also warrant further investigation in a larger clinical population.
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Affiliation(s)
- Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, United states of America.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, United states of America
| | - Rizwan Ahmad
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, United states of America
| | - Renee Miller
- Department of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, United states of America.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, United states of America.,Internal Medicine-Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, United states of America
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13
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Dong H, Jin N, Kannengiesser S, Raterman B, White RD, Kolipaka A. Magnetic resonance elastography for estimating in vivo stiffness of the abdominal aorta using cardiac-gated spin-echo echo-planar imaging: a feasibility study. NMR Biomed 2021; 34:e4420. [PMID: 33021342 DOI: 10.1002/nbm.4420] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/02/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
INTRODUCTION Magnetic resonance elastography (MRE)-derived aortic stiffness is a potential biomarker for multiple cardiovascular diseases. Currently, gradient-recalled echo (GRE) MRE is a widely accepted technique to estimate aortic stiffness. However, multi-slice GRE MRE requires multiple breath-holds (BHs), which can be challenging for patients who cannot consistently hold their breath. The aim of this study was to investigate the feasibility of a multi-slice spin-echo echo-planar imaging (SE-EPI) MRE sequence for quantifying in vivo aortic stiffness using a free-breathing (FB) protocol and a single-BH protocol. METHOD On Scanner 1, 25 healthy subjects participated in the validation of FB SE-EPI against FB GRE. On Scanner 2, another 15 healthy subjects were recruited to compare FB SE-EPI with single-BH SE-EPI. Among all volunteers, five participants were studied on both scanners to investigate the inter-scanner reproducibility of FB SE-EPI aortic MRE. Bland-Altman analysis, Lin's concordance correlation coefficient (LCCC) and coefficient of variation (COV) were evaluated. The phase-difference signal-to-noise ratios (PD SNR) were compared. RESULTS Aortic MRE using FB SE-EPI and FB GRE yielded similar stiffnesses (paired t-test, P = 0.19), with LCCC = 0.97. The FB SE-EPI measurements were reproducible (intra-scanner LCCC = 0.96) and highly repeatable (LCCC = 0.99). The FB SE-EPI MRE was also reproducible across different scanners (inter-scanner LCCC = 0.96). Single-BH SE-EPI scans yielded similar stiffness to FB SE-EPI scans (LCCC = 0.99) and demonstrated a low COV of 2.67% across five repeated measurements. CONCLUSION Multi-slice SE-EPI aortic MRE using an FB protocol or a single-BH protocol is reproducible and repeatable with advantage over multi-slice FB GRE in reducing acquisition time. Additionally, FB SE-EPI MRE provides a potential alternative to BH scans for patients who have challenges in holding their breath.
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Affiliation(s)
- Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Ning Jin
- Siemens Medical Solution, Columbus, Ohio, USA
| | | | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Richard D White
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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14
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Manduca A, Bayly PJ, Ehman RL, Kolipaka A, Royston TJ, Sack I, Sinkus R, Van Beers BE. MR elastography: Principles, guidelines, and terminology. Magn Reson Med 2020; 85:2377-2390. [PMID: 33296103 DOI: 10.1002/mrm.28627] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/20/2020] [Accepted: 11/09/2020] [Indexed: 12/13/2022]
Abstract
Magnetic resonance elastography (MRE) is a phase contrast-based MRI technique that can measure displacement due to propagating mechanical waves, from which material properties such as shear modulus can be calculated. Magnetic resonance elastography can be thought of as quantitative, noninvasive palpation. It is increasing in clinical importance, has become widespread in the diagnosis and staging of liver fibrosis, and additional clinical applications are being explored. However, publications have reported MRE results using many different parameters, acquisition techniques, processing methods, and varied nomenclature. The diversity of terminology can lead to confusion (particularly among clinicians) about the meaning of and interpretation of MRE results. This paper was written by the MRE Guidelines Committee, a group formalized at the first meeting of the ISMRM MRE Study Group, to clarify and move toward standardization of MRE nomenclature. The purpose of this paper is to (1) explain MRE terminology and concepts to those not familiar with them, (2) define "good practices" for practitioners of MRE, and (3) identify opportunities to standardize terminology, to avoid confusion.
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Affiliation(s)
- Armando Manduca
- Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Philip J Bayly
- Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Richard L Ehman
- Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Arunark Kolipaka
- Department of Radiology, Ohio State University, Columbus, Ohio, USA
| | - Thomas J Royston
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Ingolf Sack
- Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ralph Sinkus
- Imaging Sciences & Biomedical Engineering, Kings College London, London, United Kingdom
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15
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Gandhi D, Kalra P, Raterman B, Mo X, Dong H, Kolipaka A. Magnetic resonance elastography-derived stiffness of the kidneys and its correlation with water perfusion. NMR Biomed 2020; 33:e4237. [PMID: 31889353 PMCID: PMC7060814 DOI: 10.1002/nbm.4237] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 09/23/2019] [Accepted: 11/10/2019] [Indexed: 05/09/2023]
Abstract
Stiffness plays an important role in diagnosing renal fibrosis. However, kidney stiffness is altered by perfusion changes in many kidney diseases. Therefore, the aim of the current study is to determine the correlation of kidney stiffness with water intake. We hypothesize that kidney stiffness will increase with 1 L of water intake due to increased water perfusion to the kidneys. Additionally, stiffness of the kidneys will correlate with apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values before and after water intake. A 3 T MRI scanner was used to perform magnetic resonance elastography and diffusion tensor imaging of the kidneys on 24 healthy subjects (age range: 22-66 years) before and after water intake of 1 L. A 3D T1-weighted bladder scan was also performed to measure bladder volume before and after water intake. A paired t-test was performed to evaluate the effect of water intake on the stiffness of kidneys, in addition to bladder volume. A Spearman correlation test was performed to determine the association between stiffness, bladder volume, ADC and FA values of both kidneys before and after water intake. The results show a significant increase in stiffness in different regions of the kidney (ie, percentage increase ranged from 3.6% to 7.5%) and bladder volume after water intake (all P < 0.05). A moderate significant negative correlation was observed between change in kidney stiffness and bladder volume (concordance correlation coefficient = -0.468, P < 0.05). No significant correlation was observed between stiffness and ADC or FA values before and after water intake in both kidneys (P > 0.05). Water intake caused a significant increase in the stiffness of the kidneys. The negative correlation between the change in kidney stiffness and bladder volume, before and after water intake, indicates higher perfusion pressure in the kidneys, leading to increased stiffness.
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Affiliation(s)
- Deep Gandhi
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Prateek Kalra
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, OH
| | - Huiming Dong
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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16
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Majeed W, Kalra P, Kolipaka A. Simultaneous multislice rapid magnetic resonance elastography of the liver. NMR Biomed 2020; 33:e4252. [PMID: 31971301 PMCID: PMC7286422 DOI: 10.1002/nbm.4252] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 12/09/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
To design and validate a rapid Simultaneous Multi-slice (SMS) Magnetic Resonance Elastography technique (MRE), which combines SMS acquisition, in-plane undersampling and an existing rapid Magnetic Resonance Elastography (MREr) scheme to allow accelerated data acquisition in healthy volunteers and comparison against MREr. SMS-MREr sequence was developed by incorporating SMS acquisition scheme into an existing MREr sequence that accelerates MRE acquisition by acquiring data during opposite phases of mechanical vibrations. The MREr sequence accelerated MRE acquisition by acquiring data during opposite phases of mechanical vibrations. Liver MRE was performed on 23 healthy subjects using MREr and SMS-MREr sequences, and mean stiffness values were obtained for manually drawn regions of interest. Linear correlation and agreement between MREr- and SMS-MREr-based stiffness values were investigated. SMS-MREr reduced the scan time by half relative to MREr, and allowed acquisition of four-slice MRE data in a single 17-second breath-hold. Visual comparison suggested agreement between MREr and SMS-MREr elastograms. A Pearson's correlation of 0.93 was observed between stiffness values derived from MREr and SMS-MREr. Bland-Altman analysis demonstrated good agreement, with -0.08 kPa mean bias and narrow limits of agreement (95% CI: 0.23 to -0.39 kPa) between stiffness values obtained using MREr and SMS-MREr. SMS can be combined with other fast MRE approaches to achieve further acceleration. This pushes the limit on the acceleration that can be achieved in MRE acquisition, and makes it possible to conduct liver MRE exams in a single breath-hold.
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Affiliation(s)
- Waqas Majeed
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Prateek Kalra
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
| | - Arunark Kolipaka
- Department of RadiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
- Department of Internal Medicine ‐ Division of CardiologyThe Ohio State University Wexner Medical CenterColumbusOhioUSA
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17
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Gandhi D, Kalra P, Raterman B, Mo X, Dong H, Kolipaka A. Magnetic Resonance Elastography of kidneys: SE-EPI MRE reproducibility and its comparison to GRE MRE. NMR Biomed 2019; 32:e4141. [PMID: 31329347 PMCID: PMC6817380 DOI: 10.1002/nbm.4141] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 05/09/2019] [Accepted: 06/17/2019] [Indexed: 05/10/2023]
Abstract
The purpose of this study is 1) to demonstrate reproducibility of spin echo-echo planar imaging (SE-EPI) magnetic resonance elastography (MRE) to estimate kidney stiffness; and 2) to compare SE-EPI MRE and gradient recalled echo (GRE) MRE-derived stiffness estimations in various anatomical regions of the kidney. Kidney MRE was performed on 33 healthy subjects (8 for SE-EPI MRE reproducibility and 25 for comparison with GRE MRE; age range: 22-66 years) in a 3 T MRI scanner. To demonstrate SE-EPI MRE reproducibility, subjects were scanned for the first scan and then asked to leave the scan room and repositioned again for the second (repeat) scan. Similar set-up was used for GRE MRE as well. The displacement data was then processed to obtain overall stiffness estimates of the kidney. Concordance correlation analyses were performed to determine SE-EPI MRE reproducibility and agreement between GRE MRE and SE-EPI MRE derived stiffness. A high concordance correlation (ρc = 0.95; p-value<0.0001) was obtained for SE-EPI MRE reproducibility. Good concordance correlation was observed (ρc = 0.84; p < 0.0001 for both kidneys, ρc = 0.91; p < 0.0001 for right kidney and ρc = 0.78; p < 0.0001 for left kidney) between GRE MRE and SE-EPI MRE derived stiffness measurements. Paired t-test results showed that stiffness value of medulla was significantly (p < 0.0001) greater than cortex using SE-EPI MRE as well as GRE MRE. SE-EPI MRE was reproducible and good agreement was observed in MRE-derived stiffness measurements obtained using SE-EPI and GRE sequences. Therefore, SE-EPI can be used for kidney MRE applications.
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Affiliation(s)
- Deep Gandhi
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Prateek Kalra
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, OH
| | - Huiming Dong
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH
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18
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Tirkes T, Yadav D, Conwell DL, Territo PR, Zhao X, Venkatesh SK, Kolipaka A, Li L, Pisegna JR, Pandol SJ, Park WG, Topazian M, Serrano J, Fogel EL. Magnetic resonance imaging as a non-invasive method for the assessment of pancreatic fibrosis (MINIMAP): a comprehensive study design from the consortium for the study of chronic pancreatitis, diabetes, and pancreatic cancer. Abdom Radiol (NY) 2019; 44:2809-2821. [PMID: 31089778 DOI: 10.1007/s00261-019-02049-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Characteristic features of chronic pancreatitis (CP) may be absent on standard imaging studies. Quantitative Magnetic Resonance Imaging (MRI) techniques such as T1 mapping, extracellular volume (ECV) fraction, diffusion-weighted imaging (DWI) with apparent diffusion coefficient map (ADC), MR elastography (MRE), and T1-weighted signal intensity ratio (SIR) have shown promise for the diagnosis and grading severity of CP. However, radiologists still use the Cambridge classification which is based on traditional ductal imaging alone. There is an urgent need to develop new diagnostic criteria that incorporate both parenchymal and ductal features of CP seen by MRI/MRCP. Designed to fulfill this clinical need, we present the MINIMAP study, which was funded in September 2018 by the National Institutes of Health. This is a comprehensive quantitative MR imaging study which will be performed at multiple institutions in well-phenotyped CP patient cohorts. We hypothesize that quantitative MRI/MRCP features can serve as valuable non-invasive imaging biomarkers to detect and grade CP. We will evaluate the role of T1 relaxometry, ECV, T1-weighted gradient echo SIR, MRE, arteriovenous enhancement ratio, ADC, pancreas volume/atrophy, pancreatic fat fraction, ductal features, and pancreatic exocrine output following secretin stimulation in the assessment of CP. We will attempt to generate a multi-parametric pancreatic tissue fibrosis (PTF) scoring system. We anticipate that a quantitative scoring system may serve as a biomarker of pancreatic fibrosis; hence this imaging technique can be used in clinical practice as well as clinical trials to evaluate the efficacy of agents which may slow the progression or reverse measures of CP.
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Affiliation(s)
- Temel Tirkes
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 550N. University Blvd. Suite 0663, Indianapolis, IN, 46202, USA.
| | - Dhiraj Yadav
- Division of Gastroenterology, Hepatology & Nutrition, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Darwin L Conwell
- Department of Medicine, Division of Gastroenterology, Hepatology & Nutrition, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Paul R Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, R2 E124G, Indianapolis, IN, 46202, USA
| | - Xuandong Zhao
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, R2 E124G, Indianapolis, IN, 46202, USA
| | | | - Arunark Kolipaka
- The Ohio State University Wexner Medical Center, 395 West 12th AVE, 4th Floor, Columbus, OH, 43210, USA
| | - Liang Li
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Joseph R Pisegna
- Division of Gastroenterology and Hepatology, Departments of Medicine and Human Genetics, VA Greater Los Angeles HCS, Los Angeles, CA, USA
| | - Stephen J Pandol
- Division of Digestive and Liver Diseases, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Walter G Park
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University Medical Center, Stanford, CA, USA
| | - Mark Topazian
- Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic Campus, Rochester, MN, USA
| | - Jose Serrano
- CAPT, Medical Corps US Public Health Service, Division of Digestive Diseases and Nutrition, National Institute of Diabetes and Digestive and Kidney Diseases, 2 Democracy Plaza, Room 6007, MSC 5450, Bethesda, MD, 20892, USA
| | - Evan L Fogel
- Lehman, Bucksot and Sherman Section of Pancreatobiliary Endoscopy, Indiana University School of Medicine, Indianapolis, IN, USA
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19
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Kalra P, Raterman B, Mo X, Kolipaka A. Magnetic resonance elastography of brain: Comparison between anisotropic and isotropic stiffness and its correlation to age. Magn Reson Med 2019; 82:671-679. [PMID: 30957304 PMCID: PMC6510588 DOI: 10.1002/mrm.27757] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/04/2019] [Accepted: 03/08/2019] [Indexed: 12/13/2022]
Abstract
PURPOSE Noninvasive measurement of mechanical properties of brain tissue using magnetic resonance elastography (MRE) has been a promising method for investigating neurologic disorders such as multiple sclerosis, hydrocephalus, and Alzheimer's. However, because of the regional and directional dependency of brain stiffness, estimating anisotropic stiffness is important. This study investigates isotropic and anisotropic stiffness as a function of age as well as the correlation between isotropic and anisotropic stiffness. METHODS MRE and diffusion tensor imaging (DTI) were performed on 28 healthy subjects with age ranges between 18-62 y. Isotropic and anisotropic stiffness was measured and compared with age for different regions of interest such as the thalamus, corpus callosum, gray matter, white matter, and whole brain. RESULTS Isotropic stiffness in gray matter (rs = -0.57; P = 0.001) showed a significant decrease with age. Anisotropic stiffness in gray matter showed a significant decrease with age in C11 through C66 and in the thalamus, only in C33 . Between anisotropic and isotropic stiffness, gray matter showed a significant positive correlation in C11 through C66 , C22 and C66 showed a significant negative correlation in the thalamus and whole brain, and C44 showed a negative correlation in the corpus callosum. No significant difference between genders was observed in any measurements. CONCLUSION This study demonstrated a change in isotropic and anisotropic stiffness with age in different regions of the brain along with a correlation of anisotropic stiffness to isotropic stiffness.
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Affiliation(s)
- Prateek Kalra
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, Ohio State University, Columbus, Ohio
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
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20
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Fakhouri F, Dong H, Kolipaka A. Magnetic resonance elastography of the lungs: A repeatability and reproducibility study. NMR Biomed 2019; 32:e4102. [PMID: 31087728 DOI: 10.1002/nbm.4102] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 02/25/2019] [Accepted: 03/07/2019] [Indexed: 05/17/2023]
Abstract
Lung diseases are one of the leading causes of death worldwide, from which four million people die annually. Lung diseases are associated with changes in the mechanical properties of the lungs. Several studies have shown the feasibility of using magnetic resonance elastography (MRE) to quantify the lungs' shear stiffness. The aim of this study is to investigate the reproducibility and repeatability of lung MRE, and its shear stiffness measurements, obtained using a modified spin echo-echo planar imaging (SE-EPI) MRE sequence. In this study, 21 healthy volunteers were scanned twice by repositioning the volunteers to image right lung both at residual volume (RV) and total lung capacity (TLC) to assess the reproducibility of lung shear stiffness measurements. Additionally, 19 out of the 21 volunteers were scanned immediately without moving the volunteers to test the repeatability of the modified SE-EPI MRE sequence. A paired t-test was performed to determine the significant difference between stiffness measurements obtained at RV and TLC. Concordance correlation and Bland-Altman's analysis were performed to determine the reproducibility and repeatability of the SE-EPI MRE-derived shear stiffness measurements. The SE-EPI MRE sequence is highly repeatable with a concordance correlation coefficient (CCC) of 0.95 at RV and 0.96 at TLC. Similarly, the stiffness measurements obtained across all volunteers were highly reproducible with a CCC of 0.95 at RV and 0.92 at TLC. The mean shear stiffness of the lung at RV was 0.93 ± 0.22 kPa and at TLC was 1.41 ± 0.41 kPa. TLC showed a significantly higher mean shear stiffness (P = 0.0004) compared with RV. Lung MRE stiffness measurements obtained using the SE-EPI sequence were reproducible and repeatable, both at RV and TLC. Lung shear stiffness changes across respiratory cycle with significantly higher stiffness at TLC than RV.
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Affiliation(s)
- Faisal Fakhouri
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Huiming Dong
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Arunark Kolipaka
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
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21
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Khan S, Fakhouri F, Majeed W, Kolipaka A. Cardiovascular magnetic resonance elastography: A review. NMR Biomed 2018; 31:e3853. [PMID: 29193358 PMCID: PMC5975119 DOI: 10.1002/nbm.3853] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/25/2017] [Accepted: 09/29/2017] [Indexed: 05/19/2023]
Abstract
Cardiovascular diseases are the leading cause of death worldwide. These cardiovascular diseases are associated with mechanical changes in the myocardium and aorta. It is known that stiffness is altered in many diseases, including the spectrum of ischemia, diastolic dysfunction, hypertension and hypertrophic cardiomyopathy. In addition, the stiffness of the aortic wall is altered in multiple diseases, including hypertension, coronary artery disease and aortic aneurysm formation. For example, in diastolic dysfunction in which the ejection fraction is preserved, stiffness can potentially be an important biomarker. Similarly, in aortic aneurysms, stiffness can provide valuable information with regard to rupture potential. A number of studies have addressed invasive and non-invasive approaches to test and measure the mechanical properties of the myocardium and aorta. One of the non-invasive approaches is magnetic resonance elastography (MRE). MRE is a phase-contrast magnetic resonance imaging technique that measures tissue stiffness non-invasively. This review article highlights the technical details and application of MRE in the quantification of myocardial and aortic stiffness in different disease states.
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Affiliation(s)
- Saad Khan
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Faisal Fakhouri
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Waqas Majeed
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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22
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Miller R, Kolipaka A, Nash MP, Young AA. Relative identifiability of anisotropic properties from magnetic resonance elastography. NMR Biomed 2018; 31:e3848. [PMID: 29106765 PMCID: PMC5936684 DOI: 10.1002/nbm.3848] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/31/2017] [Accepted: 09/20/2017] [Indexed: 05/24/2023]
Abstract
Although magnetic resonance elastography (MRE) has been used to estimate isotropic stiffness in the heart, myocardium is known to have anisotropic properties. This study investigated the determinability of global transversely isotropic material parameters using MRE and finite-element modeling (FEM). A FEM-based material parameter identification method, using a displacement-matching objective function, was evaluated in a gel phantom and simulations of a left ventricular (LV) geometry with a histology-derived fiber field. Material parameter estimation was performed in the presence of Gaussian noise. Parameter sweeps were analyzed and characteristics of the Hessian matrix at the optimal solution were used to evaluate the determinability of each constitutive parameter. Four out of five material stiffness parameters (Young's modulii E1 and E3 , shear modulus G13 and damping coefficient s), which describe a transversely isotropic linear elastic material, were well determined from the MRE displacement field using an iterative FEM inversion method. However, the remaining parameter, Poisson's ratio, was less identifiable. In conclusion, Young's modulii, shear modulii and damping can theoretically be well determined from MRE data, but Poisson's ratio is not as well determined and could be set to a reasonable value for biological tissue (close to 0.5).
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Affiliation(s)
- Renee Miller
- Department of Anatomy and Medical Imaging, University of Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, New Zealand
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, USA
| | - Martyn P Nash
- Auckland Bioengineering Institute, University of Auckland, New Zealand
- Department of Engineering Science, University of Auckland, New Zealand
| | - Alistair A Young
- Department of Anatomy and Medical Imaging, University of Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, New Zealand
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23
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Abstract
The mechanical properties of soft tissues are closely associated with a variety of diseases. This motivates the development of elastography techniques in which tissue mechanical properties are quantitatively estimated through imaging. Magnetic resonance elastography (MRE) is a noninvasive phase-contrast MR technique wherein shear modulus of soft tissue can be spatially and temporally estimated. MRE has recently received significant attention due to its capability in noninvasively estimating tissue mechanical properties, which can offer considerable diagnostic potential. In this work, recent technology advances of MRE, its future clinical applications, and the related limitations will be discussed.
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Affiliation(s)
- Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Richard D. White
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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24
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Kolipaka A, Wassenaar PA, Cha S, Marashdeh WM, Mo X, Kalra P, Gans B, Raterman B, Bourekas E. Magnetic resonance elastography to estimate brain stiffness: Measurement reproducibility and its estimate in pseudotumor cerebri patients. Clin Imaging 2018; 51:114-122. [PMID: 29459315 PMCID: PMC6087505 DOI: 10.1016/j.clinimag.2018.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/08/2018] [Accepted: 02/02/2018] [Indexed: 01/01/2023]
Abstract
This study determines the reproducibility of magnetic resonance elastography (MRE) derived brain stiffness in normal volunteers and compares it against pseudotumor patients before and after lumbar puncture (LP). MRE was performed on 10 normal volunteers for reproducibility and 14 pseudotumor patients before and after LP. During LP, opening and closing cerebrospinal fluid (CSF) pressures were recorded before and after removal of CSF and correlated to brain stiffness. Stiffness reproducibility was observed (r > 0.78; p < 0.008). Whole brain opening LP stiffness was significantly (p = 0.04) higher than normals, but no significant difference (p = 0.11) in closing LP measurements. No significant correlation was observed between opening and closing pressure and brain stiffness.
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Affiliation(s)
- Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
| | - Peter A Wassenaar
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Sangmin Cha
- Electrical and Computer Engineering, The Ohio State University, Columbus, OH, USA
| | - Wael M Marashdeh
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Xiaokui Mo
- Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - Prateek Kalra
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Bradley Gans
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Eric Bourekas
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
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25
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Miller R, Kolipaka A, Nash MP, Young AA. Estimation of transversely isotropic material properties from magnetic resonance elastography using the optimised virtual fields method. Int J Numer Method Biomed Eng 2018; 34. [PMID: 29528568 PMCID: PMC5993646 DOI: 10.1002/cnm.2979] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Magnetic resonance elastography (MRE) has been used to estimate isotropic myocardial stiffness. However, anisotropic stiffness estimates may give insight into structural changes that occur in the myocardium as a result of pathologies such as diastolic heart failure. The virtual fields method (VFM) has been proposed for estimating material stiffness from image data. This study applied the optimised VFM to identify transversely isotropic material properties from both simulated harmonic displacements in a left ventricular (LV) model with a fibre field measured from histology as well as isotropic phantom MRE data. Two material model formulations were implemented, estimating either 3 or 5 material properties. The 3-parameter formulation writes the transversely isotropic constitutive relation in a way that dissociates the bulk modulus from other parameters. Accurate identification of transversely isotropic material properties in the LV model was shown to be dependent on the loading condition applied, amount of Gaussian noise in the signal, and frequency of excitation. Parameter sensitivity values showed that shear moduli are less sensitive to noise than the other parameters. This preliminary investigation showed the feasibility and limitations of using the VFM to identify transversely isotropic material properties from MRE images of a phantom as well as simulated harmonic displacements in an LV geometry.
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Affiliation(s)
- Renee Miller
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Martyn P. Nash
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Department of Engineering Science, University of Auckland, Auckland, New Zealand
| | - Alistair A. Young
- Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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26
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Ebersole C, Ahmad R, Rich AV, Potter LC, Dong H, Kolipaka A. A bayesian method for accelerated magnetic resonance elastography of the liver. Magn Reson Med 2018; 80:1178-1188. [PMID: 29334131 DOI: 10.1002/mrm.27083] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 12/08/2017] [Accepted: 12/18/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Christopher Ebersole
- Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio, USA.,Department of Radiology, Ohio State University, Ohio State University, Columbus, Ohio, USA
| | - Rizwan Ahmad
- Department of Biomedical Engineering, Ohio State University, Ohio State University, Columbus, Ohio, USA
| | - Adam V Rich
- Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio, USA
| | - Lee C Potter
- Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio, USA
| | - Huiming Dong
- Department of Radiology, Ohio State University, Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, Ohio State University, Ohio State University, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio, USA.,Department of Radiology, Ohio State University, Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, Ohio State University, Ohio State University, Columbus, Ohio, USA
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27
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Walter BA, Mageswaran P, Mo X, Boulter DJ, Mashaly H, Nguyen XV, Prevedello LM, Thoman W, Raterman BD, Kalra P, Mendel E, Marras WS, Kolipaka A. MR Elastography-derived Stiffness: A Biomarker for Intervertebral Disc Degeneration. Radiology 2017; 285:167-175. [PMID: 28471737 DOI: 10.1148/radiol.2017162287] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Purpose To determine the repeatability of magnetic resonance (MR) elastography-derived shear stiffness measurements of the intervertebral disc (IVD) taken throughout the day and their relationship with IVD degeneration and subject age. Materials and Methods In a cross-sectional study, in vivo lumbar MR elastography was performed once in the morning and once in the afternoon in 47 subjects without current low back pain (IVDs = 230; age range, 20-71 years) after obtaining written consent under approval of the institutional review board. The Pfirrmann degeneration grade and MR elastography-derived shear stiffness of the nucleus pulposus and annulus fibrosus regions of all lumbar IVDs were assessed by means of principal frequency analysis. One-way analysis of variance, paired t tests, concordance and Bland-Altman tests, and Pearson correlations were used to evaluate degeneration, diurnal changes, repeatability, and age effects, respectively. Results There were no significant differences between morning and afternoon shear stiffness across all levels and there was very good technical repeatability between the morning and afternoon imaging results for both nucleus pulposus (R = 0.92) and annulus fibrosus (R = 0.83) regions. There was a significant increase in both nucleus pulposus and annulus fibrosus MR elastography-derived shear stiffness with increasing Pfirrmann degeneration grade (nucleus pulposus grade 1, 12.5 kPa ± 1.3; grade 5, 16.5 kPa ± 2.1; annulus fibrosus grade 1, 90.4 kPa ± 9.3; grade 5, 120.1 kPa ± 15.4), and there were weak correlations between shear stiffness and age across all levels (R ≤ 0.32). Conclusion Our results demonstrate that MR elastography-derived shear stiffness measurements are highly repeatable, weakly correlate with age, and increase with advancing IVD degeneration. These results suggest that MR elastography-derived shear stiffness may provide an objective biomarker of the IVD degeneration process. © RSNA, 2017 Online supplemental material is available for this article.
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Affiliation(s)
- Benjamin A Walter
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Prasath Mageswaran
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Xiaokui Mo
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Daniel J Boulter
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Hazem Mashaly
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Xuan V Nguyen
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Luciano M Prevedello
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - William Thoman
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Brian D Raterman
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Prateek Kalra
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ehud Mendel
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - William S Marras
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Arunark Kolipaka
- From the Spine Research Institute (B.A.W., P.M., H.M., W.T., E.M., W.S.M., A.K.), Department of Biomedical Engineering (B.A.W., A.K.), Department of Integrated Systems Engineering (P.M., W.S.M.), and Department of Biomedical Informatics (X.M.), the Ohio State University, 395 W 12th Ave, 4th Floor Radiology, Columbus, OH 43210; and Departments of Radiology (D.J.B., X.V.N., L.M.P., B.D.R., P.K., A.K.) and Neurologic Surgery (H.M., W.T., E.M.), the Ohio State University Wexner Medical Center, Columbus, Ohio
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Kolipaka A, Schroeder S, Mo X, Shah Z, Hart PA, Conwell DL. Magnetic resonance elastography of the pancreas: Measurement reproducibility and relationship with age. Magn Reson Imaging 2017; 42:1-7. [PMID: 28476308 DOI: 10.1016/j.mri.2017.04.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 04/20/2017] [Accepted: 04/30/2017] [Indexed: 02/07/2023]
Abstract
PURPOSE To determine magnetic resonance elastography (MRE)-derived stiffness of pancreas in healthy volunteers with emphasis on: 1) short term and midterm repeatability; and 2) variance as a function of age. METHODS Pancreatic MRE was performed on 22 healthy volunteers (age range:20-64years) in a 3T-scanner. For evaluation of reproducibility of stiffness estimates, the scans were repeated per volunteer on the same day (short term) and one month apart (midterm). MRE wave images were analyzed using 3D inversion to estimate the stiffness of overall pancreas and different anatomic regions (i.e., head, neck, body, and tail). Concordance and Spearman correlation tests were performed to determine reproducibility of stiffness measurements and relationship to age. RESULTS A strong concordance correlation (ρc=0.99; p-value<0.001) was found between short term and midterm repeatability pancreatic stiffness measurements. Additionally, the pancreatic stiffness significantly increased with age with good Spearman correlation coefficient (all ρ>0.81; p<0.001). The older age group (>45yrs) had significantly higher stiffness compared to the younger group (≤45yrs) (p<0.001). No significant difference (p>0.05) in stiffness measurements was observed between different anatomical regions of pancreas, except neck stiffness was slightly lower (p<0.012) compared to head and overall pancreas at month 1. CONCLUSION MRE-derived pancreatic stiffness measurements are highly reproducible in the short and midterm and increase linearly with age in healthy volunteers. Further studies are needed to examine these effects in patients with various pancreatic diseases to understand potential clinical applications.
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Affiliation(s)
- Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, United States; Department of Internal Medicine-Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, United States.
| | - Samuel Schroeder
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, United States; Department of Mechanical Engineering, The Ohio State University, Columbus, OH, United States
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, OH, United States
| | - Zarine Shah
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Phil A Hart
- Division of Gastroenterology, Hepatology, and Nutrition, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Darwin L Conwell
- Division of Gastroenterology, Hepatology, and Nutrition, The Ohio State University Wexner Medical Center, Columbus, OH, United States
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Hawley JR, Kalra P, Mo X, Raterman B, Yee LD, Kolipaka A. Quantification of breast stiffness using MR elastography at 3 Tesla with a soft sternal driver: A reproducibility study. J Magn Reson Imaging 2017; 45:1379-1384. [PMID: 27779802 PMCID: PMC5395339 DOI: 10.1002/jmri.25511] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/27/2016] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Previous studies of breast MR elastography (MRE) evaluated the technique at magnetic field strengths of 1.5 Tesla (T) with the breast in contact with the driver. The aim of this study is to evaluate breast stiffness measurements and their reproducibility using a soft sternal driver at 3T and compare the results with qualitative measures of breast density. MATERIALS AND METHODS Twenty-two healthy volunteers each underwent two separate breast MRE scans in a 3T MRI. MRE vibrations were introduced into the breasts at 60 Hz using a soft sternal driver and axial slices were collected using a gradient echo MRE sequence. Mean stiffness measurements were calculated for each volunteer as well as a measure of reproducibility using concordance correlation between scans. Mean stiffness values for each volunteer were assessed and related to amounts of fibroglandular tissue (i.e., breast lobules, ducts, and fibrous connective tissue). RESULTS The stiffness values were reproducible with a significant P-value < 0.0001 between two scans with concordance correlation of 0.87 and 0.91 for center slice and grouping all slices, respectively. Volunteers with dense breasts (i.e., higher grades of fibroglandular tissue) had mean stiffness values of 0.96 kPa (center slice) and 0.92 kPa (all slices) while those without dense breasts had mean stiffness values of 0.85 kPa (center slice) and 0.83 kPa (all slices) (P ≤ 0.05). CONCLUSION Breast MRE is a reproducible technique at 3T using a soft sternal driver. Dense breasts had significantly higher stiffness measurements compared with nondense breasts. LEVEL OF EVIDENCE 2 J. MAGN. RESON. IMAGING 2017;45:1379-1384.
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Affiliation(s)
- Jeffrey R. Hawley
- Department of Radiology, The Ohio State University Wexner Medical Center Columbus, Ohio
| | - Prateek Kalra
- Department of Radiology, The Ohio State University Wexner Medical Center Columbus, Ohio
| | - Xiaokui Mo
- Department of Radiology, The Ohio State University Wexner Medical Center Columbus, Ohio
| | - Brian Raterman
- Department of Radiology, The Ohio State University Wexner Medical Center Columbus, Ohio
| | - Lisa D. Yee
- Department of Surgical Oncology, The Ohio State University Wexner Medical Center Columbus, Ohio
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center Columbus, Ohio
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Dong H, Mazumder R, Illapani VSP, Mo X, White RD, Kolipaka A. In vivo quantification of aortic stiffness using MR elastography in hypertensive porcine model. Magn Reson Med 2017; 78:2315-2321. [PMID: 28164361 DOI: 10.1002/mrm.26601] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 11/23/2016] [Accepted: 12/14/2016] [Indexed: 02/02/2023]
Abstract
PURPOSE Aortic stiffness plays an important role in evaluating and predicting the progression of systemic arterial hypertension (SAH). The aim of this study is to determine the stiffness of aortic wall using MR elastography (MRE) in a hypertensive porcine model and compare it against invasive aortic pressure measurements. METHODS Renal wrapping surgery was performed on eight pigs to induce SAH. Aortic MRE was performed at baseline and 2 months postsurgery using a retrospectively pulse-gated gradient-echo MRE sequence on a 1.5 tesla scanner. Mechanical waves of 70 Hz were introduced into the aorta. Invasive central aortic pressure measurements were obtained prior to each scan to calculate mean arterial pressure (MAP). MRE data were analyzed to obtain effective aortic stiffness. Spearman's rank correlation analysis was performed to assess the relationship between MAP and MRE-derived aortic stiffness. RESULTS Significant increase in effective aortic stiffness was observed between baseline and 2 months postsurgery measurements (paired t test; P = 0.004). The average MAP, determined by pooling all animals, was 65.24 ± 9.42 mm Hg at baseline and 92.57 ± 11.80 mm Hg 2 months postsurgery with P < 0.0001. Moderate linear correlation was observed between MAP and effective aortic stiffness (ρ = 0.52; P = 0.046). CONCLUSION This study demonstrated that, in a SAH porcine model, MRE-derived aortic stiffness increased with increase in MAP. Magn Reson Med 78:2315-2321, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Ria Mazumder
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, Widener University, Chester, Pennsylvania, USA
| | - Venkata Sita Priyanka Illapani
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - Richard D White
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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Mazumder R, Schroeder S, Clymer BD, White RD, Kolipaka A. Quantification of myocardial stiffness in heart failure with preserved ejection fraction porcine model using magnetic resonance elastography. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032527 DOI: 10.1186/1532-429x-18-s1-p29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kolipaka A, Illapani VSP, Kalra P, Garcia J, Mo X, Markl M, White RD. Quantification and comparison of 4D-flow MRI-derived wall shear stress and MRE-derived wall stiffness of the abdominal aorta. J Magn Reson Imaging 2016; 45:771-778. [PMID: 27603433 DOI: 10.1002/jmri.25445] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 08/10/2016] [Indexed: 02/01/2023] Open
Abstract
PURPOSE Aortic wall shear stress (WSSFlow ) alters endothelial function, which in-turn changes aortic wall stiffness leading to remodeling in different disease states. Therefore, the aims of this study are to determine normal physiologic correlations between: (1) Magnetic Resonance Elastography (MRE)-derived aortic wall stiffness (WSMRE ) and WSSFlow ; (2) WSMRE and mean velocity; (3) WSMRE and pulse wave velocity (PWV);( 4) WSMRE and mean peak flow; and (5) WSMRE , WSSFlow and age using MRE and 4D-flow MRI in the abdominal aorta in healthy human subjects. MATERIALS AND METHODS Cardiac-gated aortic MRE and 4D-flow MRI data were acquired in 24 healthy volunteers using a 3 Tesla scanner. For MRE, 70 Hz external motion was applied to obtain wave images in all spatial directions in a separate breathhold. Whereas, 4D-flow data was acquired under free-breathing. Wave images in all the directions were processed to obtain three-dimensional-weighted stiffness map at end-systole (ES). WSSFlow , mean velocity, PWV and mean peak flow were obtained using 4D-flow data. Pearson correlation was performed to determine association between all variables. RESULTS A significant negative correlation was observed between: (1) ES WSMRE and WSSFlow in both axial (r = -0.62; P = 0.006) and circumferential (r = -0.52; P = 0.016) directions; (2) ES WSMRE and mean velocity (r = -0.58; P = 0.012); and (3) age and WSSFlow in both axial (r = -0.71; P < 0.0001) and circumferential (r = -0.58; P = 0.0012) directions. A significant positive correlation was observed between: (1) ES WSMRE and PWV (r = 0.69; P < 0.0001); (2) ES WSMRE and mean peak flow (r = 0.53; P = 0.016); and (3) ES WSMRE and age (r = 0.63;P = 0.006). CONCLUSION The negative significant correlation between aortic WSSFlow and WSMRE in normal volunteers demonstrates a relationship between WSMRE and WSSFlow . LEVEL OF EVIDENCE 2 J. Magn. Reson. Imaging 2017;45:771-778.
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Affiliation(s)
- Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Venkata Sita Priyanka Illapani
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Prateek Kalra
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Julio Garcia
- Department of Radiology, Feinberg School of Medicine Northwestern University, Chicago, Illinois, USA
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, Columbus, Ohio, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine Northwestern University, Chicago, Illinois, USA.,Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, Illinois, USA
| | - Richard D White
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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Mazumder R, Schroeder S, Mo X, Clymer BD, White RD, Kolipaka A. In vivo quantification of myocardial stiffness in hypertensive porcine hearts using MR elastography. J Magn Reson Imaging 2016; 45:813-820. [PMID: 27564862 DOI: 10.1002/jmri.25423] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/29/2016] [Indexed: 12/24/2022] Open
Abstract
PURPOSE To determine alteration in left ventricular (LV) myocardial stiffness (MS) with hypertension (HTN). Cardiac MR elastography (MRE) was used to estimate MS in HTN induced pigs and MRE-derived MS measurements were compared against LV pressure, thickness and circumferential strain. MATERIALS AND METHODS Renal-wrapping surgery was performed to induce HTN in eight pigs. LV catheterization (to measure pressure) and cardiac MRI (1.5 Tesla; gradient echo-MRE and tagging) was performed pre-surgery at baseline (Bx), and post-surgery at month 1 (M1) and month 2 (M2). Images were analyzed to estimate LV-MS, thickness, and circumferential strain across the cardiac cycle. The associations between end-diastolic (ED) and end-systolic (ES) MS and (i) mean LV pressure; (ii) ED and ES thickness, respectively; and (iii) circumferential strain were evaluated using Spearman's correlation method. RESULTS From Bx to M2, mean pressure, MRE-derived stiffness, and thickness increased while circumferential strain decreased significantly (slope test, P ≤ 0.05). Both ED and ES MS had significant positive correlation with (i) mean pressure (ED MS: ρ = 0.56; P = 0.005 and ES MS: ρ = 0.45; P = 0.03); (ii) ED thickness ( ρ = 0.73; P < 0.0001) and ES thickness ( ρ = 0.84; P < 0.0001), respectively; but demonstrated a negative trend with circumferential strain (ED MS: ρ = 0.31 and ES MS: ρ = 0.37). CONCLUSION This study demonstrated that, in a HTN porcine model, MRE-derived MS increased with increase in pressure and thickness. LEVEL OF EVIDENCE 1 J. Magn. Reson. Imaging 2017;45:813-820.
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Affiliation(s)
- Ria Mazumder
- Department of Electrical and Computer Engineering, 205 Dreese Laboratories, The Ohio State University, Columbus, Ohio, USA.,Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, 265 Kirkbride Hall, Walnut Street, Widener University, Chester, PA
| | - Samuel Schroeder
- Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.,Department of Mechanical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, Room 320D, Lincoln Tower, Columbus, Ohio, USA
| | - Bradley D Clymer
- Department of Electrical and Computer Engineering, 205 Dreese Laboratories, The Ohio State University, Columbus, Ohio, USA
| | - Richard D White
- Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiovascular Medicine, 244 Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Radiology, Room 460, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiovascular Medicine, 244 Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA
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Mazumder R, Schroeder S, Mo X, Litsky AS, Clymer BD, White RD, Kolipaka A. In vivo magnetic resonance elastography to estimate left ventricular stiffness in a myocardial infarction induced porcine model. J Magn Reson Imaging 2016; 45:1024-1033. [PMID: 27533317 DOI: 10.1002/jmri.25432] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/04/2016] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To estimate change in left ventricular (LV) end-systolic and end-diastolic myocardial stiffness (MS) in pigs induced with myocardial infarction (MI) with disease progression using cardiac magnetic resonance elastography (MRE) and to compare it against ex vivo mechanical testing, LV circumferential strain, and magnetic resonance imaging (MRI) relaxometry parameters (T1 , T2 , and extracellular volume fraction [ECV]). MATERIALS AND METHODS MRI (1.5T) was performed on seven pigs, before surgery (Bx), and 10 (D10), and 21 (D21) days after creating MI. Cardiac MRE-derived MS was measured in infarcted region (MIR) and remote region (RR), and validated against mechanical testing-derived MS obtained postsacrifice on D21. Circumferential strain and MRI relaxometry parameters (T2 , T1 , and ECV) were also obtained. Multiparametric analysis was performed to determine correlation between cardiac MRE-derived MS and 1) strain, 2) relaxometry parameters, and 3) mechanical testing. RESULTS Mean diastolic (D10: 5.09 ± 0.6 kPa; D21: 5.45 ± 0.7 kPa) and systolic (D10: 5.72 ± 0.8 kPa; D21: 6.34 ± 1.0 kPa) MS in MIR were significantly higher (P < 0.01) compared to mean diastolic (D10: 3.97 ± 0.4 kPa; D21: 4.12 ± 0.2 kPa) and systolic (D10: 5.08 ± 0.6 kPa; and D21: 5.16 ± 0.6 kPa) MS in RR. The increase in cardiac MRE-derived MS at D21 (MIR) was consistent and correlated strongly with mechanical testing-derived MS (r(diastolic) = 0.86; r(systolic) = 0.89). Diastolic MS in MIR demonstrated a negative correlation with strain (r = 0.58). Additionally, cardiac MRE-derived MS demonstrated good correlations with post-contrast T1 (r(diastolic) = -0.549; r(systolic) = -0.741) and ECV (r(diastolic) = 0.548; r(systolic) = 0.703), and no correlation with T2 . CONCLUSION As MI progressed, cardiac MRE-derived MS increased in MIR compared to RR, which significantly correlated with mechanical testing-derived MS, T1 and ECV. LEVEL OF EVIDENCE 1 J. Magn. Reson. Imaging 2017;45:1024-1033.
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Affiliation(s)
- Ria Mazumder
- Department of Electrical and Computer Engineering, 205 Dreese Laboratories, Ohio State University, Columbus, Ohio, USA.,Department of Radiology, Ohio State University, Columbus, Ohio, USA
| | - Samuel Schroeder
- Department of Radiology, Ohio State University, Columbus, Ohio, USA.,Department of Mechanical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Xiaokui Mo
- Center for Biostatistics, Department of Biomedical Informatics, Columbus, Ohio, USA
| | - Alan S Litsky
- Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA.,Department of Orthopaedics, Columbus, Ohio, USA
| | - Bradley D Clymer
- Department of Electrical and Computer Engineering, 205 Dreese Laboratories, Ohio State University, Columbus, Ohio, USA
| | - Richard D White
- Department of Radiology, Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiovascular Medicine, 244 Davis Heart & Lung Research Institute, Ohio State University, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Radiology, Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiovascular Medicine, 244 Davis Heart & Lung Research Institute, Ohio State University, Columbus, Ohio, USA
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Mazumder R, Choi S, Clymer BD, White RD, Kolipaka A. Diffusion Tensor Imaging of Healthy and Infarcted Porcine Hearts: Study on the Impact of Formalin Fixation. J Med Imaging Radiat Sci 2016; 47:74-85. [PMID: 26989451 PMCID: PMC4790101 DOI: 10.1016/j.jmir.2015.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Due to complexities of in-vivo cardiac diffusion tensor imaging (DTI), ex-vivo formalin-fixed specimens are used to investigate cardiac remodeling in diseases, and reported results have shown conflicting trends. This study investigates the impact of formalin-fixation on diffusion properties and optimizes tracking parameters based on controls to understand remodeling in myocardial-infarction (MI). METHODS DTI was performed on 4 healthy (controls) and 4 MI induced formalin-fixed (PoMI) ex-vivo porcine hearts. Controls were scanned pre-fixation (PrCtrl) and re-scanned (PoCtrl) after formalin-fixation. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were estimated in all hearts. Tracking parameters (FA, tract termination angle (TTA), fiber-length) were optimized in controls and then used to investigate structural remodeling in PoMI hearts. RESULTS Fixation increased ADC and decreased FA. PoMI showed increased ADC but decreased FA in infarcted zone compared to remote zone. TTA showed sharp increase in slope from 5°-10°, which flattened after 25° in all groups. Mean fiber-length for different tracking length range showed that PoCtrl had shorter fibers compared to PrCtrl. Fibers around infarction were shorter in length and disarrayed compared to PoCtrl group. CONCLUSION Formalin-fixation affects diffusion properties and hence DTI parametric trends observed in pathology may be influenced by the fixation process which can cause contradictory findings.
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Affiliation(s)
- Ria Mazumder
- Department of Electrical and Computer Engineering, 205
Dreese Laboratories, 2015 Neil Avenue, The Ohio State University, Columbus, Ohio
43210, USA
| | - Seongjin Choi
- Department of Radiology, Room 460, 395 W. 12th Avenue, The
Ohio State University, Columbus, Ohio 43210, USA
| | - Bradley D. Clymer
- Department of Electrical and Computer Engineering, 205
Dreese Laboratories, 2015 Neil Avenue, The Ohio State University, Columbus, Ohio
43210, USA
| | - Richard D. White
- Department of Radiology, Room 460, 395 W. 12th Avenue, The
Ohio State University, Columbus, Ohio 43210, USA
- Department of Internal Medicine-Division of Cardiovascular
Medicine, 244 Davis Heart & Lung Research Institute, 473 W. 12th Avenue, The
Ohio State University, Columbus, Ohio 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, Room 460, 395 W. 12th Avenue, The
Ohio State University, Columbus, Ohio 43210, USA
- Department of Internal Medicine-Division of Cardiovascular
Medicine, 244 Davis Heart & Lung Research Institute, 473 W. 12th Avenue, The
Ohio State University, Columbus, Ohio 43210, USA
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Mazumder R, Clymer BD, Mo X, White RD, Kolipaka A. Adaptive anisotropic gaussian filtering to reduce acquisition time in cardiac diffusion tensor imaging. Int J Cardiovasc Imaging 2016; 32:921-34. [PMID: 26843150 DOI: 10.1007/s10554-016-0848-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 01/28/2016] [Indexed: 10/22/2022]
Abstract
Diffusion tensor imaging (DTI) is used to quantify myocardial fiber orientation based on helical angles (HA). Accurate HA measurements require multiple excitations (NEX) and/or several diffusion encoding directions (DED). However, increasing NEX and/or DED increases acquisition time (TA). Therefore, in this study, we propose to reduce TA by implementing a 3D adaptive anisotropic Gaussian filter (AAGF) on the DTI data acquired from ex-vivo healthy and infarcted porcine hearts. DTI was performed on ex-vivo hearts [9-healthy, 3-myocardial infarction (MI)] with several combinations of DED and NEX. AAGF, mean (AVF) and median filters (MF) were applied on the primary eigenvectors of the diffusion tensor prior to HA estimation. The performance of AAGF was compared against AVF and MF. Root mean square error (RMSE), concordance correlation-coefficients and Bland-Altman's technique was used to determine optimal combination of DED and NEX that generated the best HA maps in the least possible TA. Lastly, the effect of implementing AAGF on the infarcted porcine hearts was also investigated. RMSE in HA estimation for AAGF was lower compared to AVF or MF. Post-filtering (AAGF) fewer DED and NEX were required to achieve HA maps with similar integrity as those obtained from higher NEX and/or DED. Pathological alterations caused in HA orientation in the MI model were preserved post-filtering (AAGF). Our results demonstrate that AAGF reduces TA without affecting the integrity of the myocardial microstructure.
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Affiliation(s)
- Ria Mazumder
- Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Laboratories, 2015 Neil Avenue, Columbus, OH, 43210, USA.,Department of Radiology, The Ohio State University, Room 460, 395 West 12th Avenue, 4th Floor, Columbus, OH, 43210, USA
| | - Bradley D Clymer
- Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Laboratories, 2015 Neil Avenue, Columbus, OH, 43210, USA
| | - Xiaokui Mo
- Department of Biomedical Informatics, Center for Biostatistics, Room 320D, Lincoln Tower, 1800 Cannon Drive, Columbus, OH, 43210, USA
| | - Richard D White
- Department of Radiology, The Ohio State University, Room 460, 395 West 12th Avenue, 4th Floor, Columbus, OH, 43210, USA.,Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, 244 Davis Heart and Lung Research Institute, 473 W. 12th Avenue, Columbus, OH, 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University, Room 460, 395 West 12th Avenue, 4th Floor, Columbus, OH, 43210, USA. .,Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, 244 Davis Heart and Lung Research Institute, 473 W. 12th Avenue, Columbus, OH, 43210, USA.
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Illapani VSP, Garcia J, Mazumder R, White RD, Markl M, Kolipaka A. Quantification and comparison of 4D Flow MRI derived wall shear stress and MRE derived wall shear stiffness of abdominal aorta. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032092 DOI: 10.1186/1532-429x-18-s1-p360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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da Silveira JS, Scansen BA, Wassenaar PA, Raterman B, Eleswarpu C, Jin N, Mo X, White RD, Bonagura JD, Kolipaka A. Quantification of myocardial stiffness using magnetic resonance elastography in right ventricular hypertrophy: initial feasibility in dogs. Magn Reson Imaging 2015; 34:26-34. [PMID: 26471513 DOI: 10.1016/j.mri.2015.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 10/07/2015] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Myocardial stiffness is an important determinant of cardiac function and is currently invasively and indirectly assessed by catheter angiography. This study aims to demonstrate the feasibility of quantifying right ventricular (RV) stiffness noninvasively using cardiac magnetic resonance elastography (CMRE) in dogs with severe congenital pulmonary valve stenosis (PVS) causing RV hypertrophy, and compare it to remote myocardium in the left ventricle (LV). Additionally, correlations between stiffness and selected pathophysiologic indicators from transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging were explored. METHODS In-vivo CMRE was performed on nine dogs presenting severe congenital PVS using a 1.5T MRI scanner. T1-MOLLI, T2-prepared-bSSFP, gated-cine GRE-MRE and LGE (PSIR) sequences were used to acquire a basal short-axis slice. RV and LV-free-wall (FW) stiffness measurements were compared against each other and also correlated to ventricular mass, RV and LV FW thickness, T1 and T2 relaxation times, and extracellular volume fraction (ECV). Peak transpulmonary pressure gradient and myocardial strain were also acquired on eight dogs by TTE and correlated to RV-FW systolic stiffness. Potential correlations were evaluated by Spearman's rho (rs). RESULTS RV-FW stiffness was found to be significantly higher than the LV-FW stiffness both during end-systole (ES) (p=0.002) and end-diastole (ED) (p=0.029). Significant correlations were observed between RV-FW ES and LV-FW ED stiffness versus ECV (rs=0.75; p-value=0.05). Non-significant moderate correlations were found between LV-FW ES (rs=0.54) and RV-FW ED (rs=0.61) stiffness versus ECV. Furthermore, non-significant correlations were found between RV or LV-FW stiffness and the remaining variables (rs<0.54; p-value>0.05). CONCLUSION This study demonstrates the feasibility of determining RV stiffness. The positive correlations between stiffness and ECV might indicate some interdependence between stiffness and myocardial extracellular matrix alterations. However, further studies are warranted to validate our initial observations.
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Affiliation(s)
- Juliana S da Silveira
- Department of Radiology, OSU College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Brian A Scansen
- Department of Veterinary Clinical Sciences, OSU College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Peter A Wassenaar
- Department of Radiology, OSU College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Brian Raterman
- Department of Radiology, OSU College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Chethan Eleswarpu
- College of Biomedical Engineering, The Ohio State University, Columbus, OH, UTSA
| | - Ning Jin
- Siemens Medical Solutions, Malvern, PA USA
| | - Xiaokui Mo
- Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - Richard D White
- Department of Radiology, OSU College of Medicine, The Ohio State University, Columbus, OH, USA; Department of Internal Medicine/Division of Cardiovascular Medicine, OSU College of Medicine, The Ohio State University, Columbus, OH, USA
| | - John D Bonagura
- Department of Veterinary Clinical Sciences, OSU College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - Arunark Kolipaka
- Department of Radiology, OSU College of Medicine, The Ohio State University, Columbus, OH, USA; Department of Internal Medicine/Division of Cardiovascular Medicine, OSU College of Medicine, The Ohio State University, Columbus, OH, USA.
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Kenyhercz WE, Raterman B, Illapani VSP, Dowell J, Mo X, White RD, Kolipaka A. Quantification of aortic stiffness using magnetic resonance elastography: Measurement reproducibility, pulse wave velocity comparison, changes over cardiac cycle, and relationship with age. Magn Reson Med 2015; 75:1920-6. [PMID: 26096227 DOI: 10.1002/mrm.25719] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 03/11/2015] [Accepted: 03/12/2015] [Indexed: 12/22/2022]
Abstract
PURPOSE To assess MR elastography (MRE)-derived aortic shear stiffness (μMRE ) measurements for: 1) reproducibility, 2) comparison to pulse wave velocity, 3) changes over the cardiac cycle, and 4) relationship with age. METHODS Cardiac-gated aortic MRE was performed on 20 healthy volunteers (aged 20-73 years). For assessing reproducibility of stiffness measurements, scans were repeated per volunteer. MRE wave images were analyzed to obtain stiffness of the abdominal aorta across the cardiac cycle, and comparisons were made with subject age. RESULTS Analysis of concordance correlation coefficient between scans 1 and 2 showed that rc = 0.86 (95% confidence interval, 0.77, 0.94) with P < 0.0001. Significantly higher μMRE was observed for all volunteers during end-systole when compared to end-diastole (P < 0.0001). μMRE increased with age; end-systolic stiffness demonstrated a relatively stronger correlation with age (r = 0.62, P = 0.003) when compared to end-diastolic stiffness (r = 0.51, P = 0.023); and the slopes of end-systole and end-diastole were found to be significantly different (P = 0.011). [Formula: see text] at end-systole and end-diastole correlated linearly with pulse wave velocity, with an r = 0.54 (P = 0.013) and r = 0.58 (P = 0.008), respectively. CONCLUSION The results of this study indicate that MRE-derived aortic shear stiffness measurements are robust (reproducible and comparable to similar techniques). Mean μMRE was higher during end-systole when compared to end-diastole. μMRE was found to increase with age and showed a stronger correlation with end-systolic stiffness than with end-diastolic stiffness.
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Affiliation(s)
- William E Kenyhercz
- Department of Radiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Brian Raterman
- Department of Radiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Venkata Sita Priyanka Illapani
- Department of Radiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Joshua Dowell
- Department of Internal Medicine, Division of Cardiovascular Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Xiaokui Mo
- Center for Biostatistics, The Ohio State University, Columbus, Ohio, USA
| | - Richard D White
- Department of Radiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine, Division of Cardiovascular Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Radiology, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine, Division of Cardiovascular Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA
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Wassenaar PA, Eleswarpu CN, Schroeder SA, Mo X, Raterman BD, White RD, Kolipaka A. Measuring age-dependent myocardial stiffness across the cardiac cycle using MR elastography: A reproducibility study. Magn Reson Med 2015; 75:1586-93. [PMID: 26010456 DOI: 10.1002/mrm.25760] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 04/08/2015] [Accepted: 04/11/2015] [Indexed: 12/23/2022]
Abstract
PURPOSE To assess reproducibility in measuring left ventricular (LV) myocardial stiffness in volunteers throughout the cardiac cycle using MR elastography (MRE) and to determine its correlation with age. METHODS Cardiac MRE (CMRE) was performed on 29 normal volunteers, with ages ranging from 21 to 73 years. For assessing reproducibility of CMRE-derived stiffness measurements, scans were repeated per volunteer. Wave images were acquired throughout the LV myocardium, and were analyzed to obtain mean stiffness during the cardiac cycle. CMRE-derived stiffness values were correlated to age. RESULTS Concordance correlation coefficient revealed good interscan agreement with rc of 0.77, with P-value < 0.0001. Significantly higher myocardial stiffness was observed during end-systole (ES) compared with end-diastole (ED) across all subjects. Additionally, increased deviation between ES and ED stiffness was observed with increased age. CONCLUSION CMRE-derived stiffness is reproducible, with myocardial stiffness changing cyclically across the cardiac cycle. Stiffness is significantly higher during ES compared with ED. With age, ES myocardial stiffness increases more than ED, giving rise to an increased deviation between the two.
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Affiliation(s)
- Peter A Wassenaar
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Chethanya N Eleswarpu
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Samuel A Schroeder
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Mechanical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Xiaokui Mo
- Center for Biostatistics, The Ohio State University, Columbus, Ohio, USA
| | - Brian D Raterman
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Richard D White
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiovascular Medicine, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine-Division of Cardiovascular Medicine, The Ohio State University College of Medicine, Columbus, Ohio, USA
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Kenyhercz W, Damughatla A, Raterman B, Wassenaar PA, White RD, Kolipaka A. Quantification of aortic stiffness across the cardiac cycle using magnetic resonance elastography. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044450 DOI: 10.1186/1532-429x-16-s1-p389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Mazumder R, Clymer BD, White RD, Kolipaka A. Estimation of helical angle of the left ventricle using diffusion tensor imaging with minimum acquisition time. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044888 DOI: 10.1186/1532-429x-16-s1-p359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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da Silveira JS, Scansen BA, Wassenaar PA, Raterman B, Jin N, White RD, Bonagura JD, Kolipaka A. MR elastography-derived right ventricular myocardial stiffness in dogs with congenital pulmonary valve stenosis: correlation with myocardial relaxation times and ECV. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044025 DOI: 10.1186/1532-429x-16-s1-p82] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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Damughatla AR, Raterman B, Sharkey-Toppen T, Jin N, Simonetti OP, White RD, Kolipaka A. Quantification of aortic stiffness using MR elastography and its comparison to MRI-based pulse wave velocity. J Magn Reson Imaging 2013; 41:44-51. [PMID: 24243654 DOI: 10.1002/jmri.24506] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/19/2013] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To determine the correlation in abdominal aortic stiffness obtained using magnetic resonance elastography (MRE) (μ(MRE)) and MRI-based pulse wave velocity (PWV) shear stiffness (μ(PWV)) estimates in normal volunteers of varying age, and also to determine the correlation between μ(MRE) and μ(PWV). MATERIALS AND METHODS In vivo aortic MRE and MRI were performed on 21 healthy volunteers with ages ranging from 18 to 65 years to obtain wave and velocity data along the long axis of the abdominal aorta. The MRE wave images were analyzed to obtain mean stiffness and the phase contrast images were analyzed to obtain PWV measurements and indirectly estimate stiffness values from the Moens-Korteweg equation. RESULTS Both μ(MRE) and μ(PWV) measurements increased with age, demonstrating linear correlations with R(2) values of 0.81 and 0.67, respectively. Significant difference (P ≤ 0.001) in mean μ(MRE) and μ(PWV) between young and old healthy volunteers was also observed. Furthermore, a poor linear correlation of R(2) value of 0.43 was determined between μ(MRE) and μ(PWV) in the initial pool of volunteers. CONCLUSION The results of this study indicate linear correlations between μ(MRE) and μ(PWV) with normal aging of the abdominal aorta. Significant differences in mean μ(MRE) and μ(PWV) between young and old healthy volunteers were observed.
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Affiliation(s)
- Anirudh R Damughatla
- Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
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Yin M, Kolipaka A, Woodrum DA, Glaser KJ, Romano AJ, Manduca A, Talwalkar JA, Araoz PA, McGee KP, Anavekar NS, Ehman RL. Hepatic and splenic stiffness augmentation assessed with MR elastography in an in vivo porcine portal hypertension model. J Magn Reson Imaging 2013; 38:809-15. [PMID: 23418135 PMCID: PMC3661694 DOI: 10.1002/jmri.24049] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Accepted: 12/19/2012] [Indexed: 12/18/2022] Open
Abstract
PURPOSE To investigate the influence of portal pressure on the shear stiffness of the liver and spleen in a well-controlled in vivo porcine model with magnetic resonance elastography (MRE). A significant correlation between portal pressure and tissue stiffness could be used to noninvasively assess increased portal venous pressure (portal hypertension), which is a frequent clinical condition caused by cirrhosis of the liver and is responsible for the development of many lethal complications. MATERIALS AND METHODS During multiple intraarterial infusions of Dextran-40 in three adult domestic pigs in vivo, 3D abdominal MRE was performed with left ventricle and portal catheters measuring blood pressure simultaneously. Least-squares linear regressions were used to analyze the relationship between tissue stiffness and portal pressure. RESULTS Liver and spleen stiffness have a dynamic component that increases significantly following an increase in portal or left ventricular pressure. Correlation coefficients with the linear regressions between stiffness and pressure exceeded 0.8 in most cases. CONCLUSION The observed stiffness-pressure relationship of the liver and spleen could provide a promising noninvasive method for assessing portal pressure. Using MRE to study the tissue mechanics associated with portal pressure may provide new insights into the natural history and pathophysiology of hepatic diseases and may have significant diagnostic value in the future.
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Affiliation(s)
- Meng Yin
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | | | | | - Anthony J Romano
- Acoustic Division, Naval Research Laboratory, Washington, DC, USA
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Mazumder R, Choi S, Raterman B, Clymer BD, Kolipaka A, White RD. Diffusion tensor imaging of formalin fixed infarcted porcine hearts. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559266 DOI: 10.1186/1532-429x-15-s1-e103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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Mazumder R, Choi S, Raterman B, Clymer BD, Kolipaka A, White RD. Diffusion tensor imaging of formalin fixed infarcted porcine hearts: a comparison between 3T and 1.5T. J Cardiovasc Magn Reson 2013. [PMCID: PMC3560070 DOI: 10.1186/1532-429x-15-s1-w34] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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Damughatla A, Raterman B, Simonetti OP, Sharkey-Toppen T, Jin N, White RD, Kolipaka A. MR elastography as a method to estimate aortic stiffness and its comparison against MR based pulse wave velocity measurement. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559925 DOI: 10.1186/1532-429x-15-s1-p240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Anavekar NS, Wong BF, Foley TA, Bishu K, Kolipaka A, Koo CW, Khandaker MH, Oh JK, Young PM. Index of biventricular interdependence calculated using cardiac MRI: a proof of concept study in patients with and without constrictive pericarditis. Int J Cardiovasc Imaging 2012; 29:363-9. [DOI: 10.1007/s10554-012-0101-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/12/2012] [Indexed: 11/28/2022]
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