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Kafali SG, Bolster BD, Shih SF, Delgado TI, Deshpande V, Zhong X, Adamos TR, Ghahremani S, Calkins KL, Wu HH. Self-Gated Radial Free-Breathing Liver MR Elastography: Assessment of Technical Performance in Children at 3 T. J Magn Reson Imaging 2024. [PMID: 39036994 DOI: 10.1002/jmri.29541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/23/2024] Open
Abstract
BACKGROUND Conventional liver magnetic resonance elastography (MRE) requires breath-holding (BH) to avoid motion artifacts, which is challenging for children. While radial free-breathing (FB)-MRE is an alternative for quantifying liver stiffness (LS), previous methods had limitations of long scan times, acquiring two slices in 5 minutes, and not resolving motion during reconstruction. PURPOSE To reduce FB-MRE scan time to 4 minutes for four slices and to investigate the impact of self-gated (SG) motion compensation on FB-MRE LS quantification in terms of agreement, intrasession repeatability, and technical quality compared to conventional BH-MRE. STUDY TYPE Prospective. POPULATION Twenty-six children without fibrosis (median age: 12.9 years, 15 females). FIELD STRENGTH/SEQUENCE 3 T; Cartesian gradient-echo (GRE) BH-MRE, research application radial GRE FB-MRE. ASSESSMENT Participants were scanned twice to measure repeatability, without moving the table or changing the participants' position. LS was measured in areas of the liver with numerical confidence ≥90%. Technical quality was examined using measurable liver area (%). STATISTICAL TESTS Agreement of LS between BH-MRE and FB-MRE was evaluated using Bland-Altman analysis for SG acceptance rates of 40%, 60%, 80%, and 100%. LS repeatability was assessed using within-subject coefficient of variation (wCV). The differences in LS and measurable liver area were examined using Kruskal-Wallis and Wilcoxon signed-rank tests. P < 0.05 was considered significant. RESULTS FB-MRE with 60% SG achieved the closest agreement with BH-MRE (mean difference 0.00 kPa). The LS ranged from 1.70 to 1.83 kPa with no significant differences between BH-MRE and FB-MRE with varying SG rates (P = 0.52). All tested methods produced repeatable LS with wCV from 4.4% to 6.5%. The median measurable liver area was smaller for FB-MRE (32%-45%) than that for BH-MRE (91%-93%) (P < 0.05). DATA CONCLUSION FB-MRE with 60% SG can quantify LS with close agreement and comparable repeatability with respect to BH-MRE in children. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Sevgi Gokce Kafali
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
| | - Bradley D Bolster
- US MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Salt Lake City, Utah, USA
| | - Shu-Fu Shih
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
| | - Timoteo I Delgado
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Physics and Biology in Medicine Interdepartmental Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Vibhas Deshpande
- US MR R&D Collaborations, Siemens Medical Solutions USA, Inc., Austin, Texas, USA
| | - Xiaodong Zhong
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Physics and Biology in Medicine Interdepartmental Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Timothy R Adamos
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Shahnaz Ghahremani
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Kara L Calkins
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Holden H Wu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California, USA
- Physics and Biology in Medicine Interdepartmental Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
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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] [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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Zhang Y, Ye Z, Xia C, Tan Y, Zhang M, Lv X, Tang J, Li Z. Clinical Applications and Recent Updates of Simultaneous Multi-slice Technique in Accelerated MRI. Acad Radiol 2024; 31:1976-1988. [PMID: 38220568 DOI: 10.1016/j.acra.2023.12.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/16/2024]
Abstract
Simultaneous multi-slice (SMS) is a magnetic resonance imaging (MRI) acceleration technique that utilizes multi-band radio-frequency pulses to simultaneously excite and encode multiple slices. Currently, SMS has been widely studied and applied in the MRI examination to reduce acquisition time, which can significantly improve the examination efficiency and patient throughput. Moreover, SMS technique can improve spatial resolution, which is of great value in disease diagnosis, treatment response monitoring, and prognosis prediction. This review will briefly introduce the technical principles of SMS, and summarize its current clinical applications. More importantly, we will discuss the recent technical progress and future research direction of SMS, hoping to highlight the clinical value and scientific potential of this technique.
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Affiliation(s)
- Yiteng Zhang
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Zheng Ye
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Chunchao Xia
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Yuqi Tan
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Meng Zhang
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Xinyang Lv
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Jing Tang
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China
| | - Zhenlin Li
- Department of Radiology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan, China.
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Darwish OI, Gharib AM, Jeljeli S, Metwalli NS, Feeley J, Rotman Y, Brown RJ, Ouwerkerk R, Kleiner DE, Stäb D, Speier P, Sinkus R, Neji R. Single Breath-Hold 3-Dimensional Magnetic Resonance Elastography Depicts Liver Fibrosis and Inflammation in Obese Patients. Invest Radiol 2023; 58:413-419. [PMID: 36719974 PMCID: PMC10735168 DOI: 10.1097/rli.0000000000000952] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Three-dimensional (3D) magnetic resonance elastography (MRE) measures liver fibrosis and inflammation but requires several breath-holds that hamper clinical acceptance. The aim of this study was to evaluate the technical and clinical feasibility of a single breath-hold 3D MRE sequence as a means of measuring liver fibrosis and inflammation in obese patients. METHODS From November 2020 to December 2021, subjects were prospectively enrolled and divided into 2 groups. Group 1 included healthy volunteers (n = 10) who served as controls to compare the single breath-hold 3D MRE sequence with a multiple-breath-hold 3D MRE sequence. Group 2 included liver patients (n = 10) who served as participants to evaluate the clinical feasibility of the single breath-hold 3D MRE sequence in measuring liver fibrosis and inflammation. Controls and participants were scanned at 60 Hz mechanical excitation with the single breath-hold 3D MRE sequence to retrieve the magnitude of the complex-valued shear modulus (|G*| [kPa]), the shear wave speed (Cs [m/s]), and the loss modulus (G" [kPa]). The controls were also scanned with a multiple-breath-hold 3D MRE sequence for comparison, and the participants had histopathology (Ishak scores) for correlation with Cs and G". RESULTS For the 10 controls, 5 were female, and the mean age and body mass index were 33.1 ± 9.5 years and 23.0 ± 2.1 kg/m 2 , respectively. For the 10 participants, 8 were female, and the mean age and body mass index were 45.1 ± 16.5 years and 33.1 ± 4.0 kg/m 2 (obese range), respectively. All participants were suspected of having nonalcoholic fatty liver disease. Bland-Altman analysis of the comparison in controls shows there are nonsignificant differences in |G*|, Cs, and G" below 6.5%, suggesting good consensus between the 2 sequences. For the participants, Cs and G" correlated significantly with Ishak fibrosis and inflammation grades, respectively ( ρ = 0.95, P < 0.001, and ρ = 0.84, P = 0.002). CONCLUSION The single breath-hold 3D MRE sequence may be effective in measuring liver fibrosis and inflammation in obese patients.
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Affiliation(s)
- Omar Isam Darwish
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- INSERM U1148, LVTS, University Paris Diderot, Paris, France
- MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
| | - Ahmed M. Gharib
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Sami Jeljeli
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Nader S. Metwalli
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Jenna Feeley
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Yaron Rotman
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Rebecca J. Brown
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | - Ronald Ouwerkerk
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD
| | | | - Daniel Stäb
- MR Research Collaborations, Siemens Healthcare Limited, Melbourne, Australia
| | - Peter Speier
- MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany
| | - Ralph Sinkus
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- INSERM U1148, LVTS, University Paris Diderot, Paris, France
| | - Radhouene Neji
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom
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Hazhirkarzar B, Wu Q, Tang H, Baghdadi A, Motaghi M, Habibabadi RR, Shaghaghi M, Ghadimi M, Borhani A, Mohseni A, Pan L, BolsterJr BD, Kamel IR. Comparison between Gradient-Echo and Spin-Echo EPI MR Elastography at 3 T in quantifying liver stiffness of patients with and without iron overload; a prospective study. Clin Imaging 2023; 100:42-47. [PMID: 37196504 DOI: 10.1016/j.clinimag.2023.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 05/19/2023]
Abstract
OBJECTIVES To compare the maximum axial area of the confidence mask and the calculated liver stiffness (LS) on gradient-echo (GRE) and spin-echo echo planar imaging (SE-EPI) MR elastography (MRE) in patients with and without iron deposition. METHODS 104 patients underwent MRE by GRE and SE-EPI sequences at 3 T. R2* values >88 Hz in the liver were categorized in the iron overload group. The maximum axial area and the corresponding LS values were measured by manually contouring the whole area on one slice with the largest confidence mask at both GRE and SE-EPI sequences. RESULTS In patients with iron overload, SE-EPI provided larger maximum axial confidence area in unfailed images (57.6 ± 41.7 cm2) compared to GRE (45.7 ± 29.1 cm2) (p-value = 0.007). In five patients with iron overload, imaging failed at GRE sequence, whereas at the SE-EPI sequence the maximum area of the confidence mask had a mean value of 33.5 ± 54.9 cm2. In livers without iron overload (R2*: 50.7 ± 13.1 Hz), the maximum area on the confidence mask was larger at SE-EPI (118.3 ± 41.2 cm2) than on GRE (105.1 ± 31.7 cm2) (P-value = 0.003). There was no significant difference in mean LS between SE-EPI (2.0 ± 0.3 kPa) and GRE (2.1 ± 0.5 kPa) in livers with iron overload (P value = 0.24). Similarly, in the group without iron overload, mean LS was 2.3 ± 0.7 kPa at SE-EPI and 2.4 ± 0.8 kPa at GRE sequences (P-value = 0.11). CONCLUSIONS SE-EPI MRE can successfully provide similar LS measurements as GRE MRE. Furthermore, it provides a larger measurable area on the confidence mask in both groups with and without iron overload.
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Affiliation(s)
- Bita Hazhirkarzar
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Qingxia Wu
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Hao Tang
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Azarakhsh Baghdadi
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Mina Motaghi
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Roya Rezvani Habibabadi
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Mohammadreza Shaghaghi
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Maryam Ghadimi
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Ali Borhani
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Alireza Mohseni
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Li Pan
- Siemens Healthineers, Baltimore, MD, USA
| | | | - Ihab R Kamel
- Russell H. Morgan Department of Radiology and Radiological Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, 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] [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] [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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8
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Pednekar A, Gandhi D, Wang H, Tkach JA, Trout AT, Dillman JR. Performance of C-SENSE Accelerated Rapid Liver Shear Stiffness Measurement Using Displacement Wave Polarity-Inversion Motion Encoding: An Evaluation Study. J Magn Reson Imaging 2022; 56:754-765. [PMID: 35089614 DOI: 10.1002/jmri.28078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Liver shear stiffness measurement using magnetic resonance elastography (MRE) aids in the noninvasive diagnosis and staging of liver fibrosis. Inadequate breath-holds can lead to inaccurate stiffness estimation and/or failed MRE exams. PURPOSE To prospectively evaluate the performance of compressed sensitivity encoding (C-SENSE) accelerated rapid MRE measurement of liver shear stiffness using displacement wave polarity-inversion motion encoding. STUDY TYPE Retrospective. SUBJECTS Eleven with liver disease and 10 asymptomatic subjects. FIELD STRENGTH/SEQUENCE 1.5 T; gradient-recalled-echo (GRE) MRE. ASSESSMENT All participants underwent: 1) two-dimensional (2D) GRE MRE with inflow saturation using SENSE acceleration factor (R) of 2 (standard of care [SC]); 2) 2D rapid MRE with (RwS); and 3) without (RnS) inflow saturation using C-SENSE R = 3; and 4) spatial three-dimensional (3D) rapid MRE with inflow saturation (R3D) using C-SENSE R = 4; with nominally identical spatial resolution and coverage. Image analyst (D.G., 2 years of experience) drew identical and maximal regions of interest (ROIs) in right hepatic lobe. STATISTICAL TESTS Linear regression, intra-class correlation coefficients (ICC), Bland-Altman analyses, and the Wilcoxon signed-rank test were used to assess consistency and agreement of liver stiffness measurements for manually drawn identical and maximal ROIs. RESULTS In 21 participants (37 ± 14 years) with liver stiffness (2.3 ± 0.7 kPa), body mass index (BMI 27 ± 7 kg/m2 ), proton density fat fraction (PDFF 9 ± 9%), and T2 * (27 ± 4 msec); rapid MRE sequences showed excellent agreement (ICC > 0.95) with SC MRE and no correlation (r2 < 0.1) of the differences (mean difference <0.2 kPa, <6%; limits of agreement <0.4 kPa, <16%) with BMI, PDFF, and T2 *. Breath-hold times were: 14 seconds (SC), 5 seconds (RnS), 7 seconds (RwS) per slice, and 16 seconds for the R3D acquisition. DATA CONCLUSIONS C-SENSE accelerated GRE MRE sequences, using displacement wave polarity-inversion motion encoding, produce equivalent measurements of liver stiffness and have potential clinical benefit in patients with limited breath-holding capacity. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY: Stage 1.
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Affiliation(s)
- Amol Pednekar
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Deep Gandhi
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Hui Wang
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.,MR Clinical Science, Philips, Cincinnati, Ohio, USA
| | - Jean A Tkach
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Andrew T Trout
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jonathan R Dillman
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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9
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Kafali SG, Armstrong T, Shih SF, Kim GJ, Holtrop JL, Venick RS, Ghahremani S, Bolster BD, Hillenbrand CM, Calkins KL, Wu HH. Free-breathing radial magnetic resonance elastography of the liver in children at 3 T: a pilot study. Pediatr Radiol 2022; 52:1314-1325. [PMID: 35366073 PMCID: PMC9192470 DOI: 10.1007/s00247-022-05297-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/02/2021] [Accepted: 01/20/2022] [Indexed: 12/17/2022]
Abstract
BACKGROUND Magnetic resonance (MR) elastography of the liver measures hepatic stiffness, which correlates with the histopathological staging of liver fibrosis. Conventional Cartesian gradient-echo (GRE) MR elastography requires breath-holding, which is challenging for children. Non-Cartesian radial free-breathing MR elastography is a potential solution to this problem. OBJECTIVE To investigate radial free-breathing MR elastography for measuring hepatic stiffness in children. MATERIALS AND METHODS In this prospective pilot study, 14 healthy children and 9 children with liver disease were scanned at 3 T using 2-D Cartesian GRE breath-hold MR elastography (22 s/slice) and 2-D radial GRE free-breathing MR elastography (163 s/slice). Each sequence was acquired twice. Agreement in the stiffness measurements was evaluated using Lin's concordance correlation coefficient (CCC) and within-subject mean difference. The repeatability was assessed using the within-subject coefficient of variation and intraclass correlation coefficient (ICC). RESULTS Fourteen healthy children and seven children with liver disease completed the study. Median (±interquartile range) normalized measurable liver areas were 62.6% (±26.4%) and 44.1% (±39.6%) for scan 1, and 60.3% (±21.8%) and 43.9% (±44.2%) for scan 2, for Cartesian and radial techniques, respectively. Hepatic stiffness from the Cartesian and radial techniques had close agreement with CCC of 0.89 and 0.94, and mean difference of 0.03 kPa and -0.01 kPa, for scans 1 and 2. Cartesian and radial techniques achieved similar repeatability with within-subject coefficient of variation=1.9% and 3.4%, and ICC=0.93 and 0.92, respectively. CONCLUSION In this pilot study, radial free-breathing MR elastography was repeatable and in agreement with Cartesian breath-hold MR elastography in children.
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Affiliation(s)
- Sevgi Gokce Kafali
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095 USA ,Department of Bioengineering, University of California Los Angeles, Los Angeles, CA USA
| | - Tess Armstrong
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095 USA
| | - Shu-Fu Shih
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095 USA ,Department of Bioengineering, University of California Los Angeles, Los Angeles, CA USA
| | - Grace J. Kim
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095 USA
| | - Joseph L. Holtrop
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN USA
| | - Robert S. Venick
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA USA
| | - Shahnaz Ghahremani
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095 USA
| | | | - Claudia M. Hillenbrand
- Department of Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN USA ,Research Imaging NSW, University of New South Wales, Sydney, Australia
| | - Kara L. Calkins
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA USA
| | - Holden H. Wu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, 300 UCLA Medical Plaza, Suite B119, Los Angeles, CA 90095 USA ,Department of Bioengineering, University of California Los Angeles, Los Angeles, CA USA
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10
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Practical and clinical applications of pancreatic magnetic resonance elastography: a systematic review. Abdom Radiol (NY) 2021; 46:4744-4764. [PMID: 34076721 DOI: 10.1007/s00261-021-03143-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 12/13/2022]
Abstract
Magnetic resonance elastography (MRE) is a non-invasive technique suitable for assessing mechanical properties of tissues, i.e., stiffness. MRE of the pancreas is relatively new, but recently an increasing number of studies have successfully assessed pancreas diseases with MRE aiming to differentiate healthy from pathological pancreatic tissue with or without fibrosis. This review will systematically describe the practical and clinical applications of pancreatic MRE. We conducted a systematic literature search with a pre-specified search strategy using PubMed and Embase according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. English peer-reviewed articles applying MRE of the pancreas were included. Two independent reviewers assessed the studies. The literature search yielded 14 studies. The pancreatic stiffness for healthy volunteers ranged from 1.11. to 1.21 kPa at a driver frequency of 40 Hz. In benign tumors, the stiffness values were slightly higher or sometimes even lower (range 0.78 to 2.00 kPa), compared to the healthy pancreas parenchyma whereas, in malignant tumors, the stiffness values tended to be higher (1.42 to 6.06 kPa). The pancreatic stiffness was increased in both acute (median: 1.99 kPa) and chronic pancreatitis (> 1.50 kPa). MRE is a promising technique for detecting and quantifying pancreatic stiffness. It is related to fibrosis and seems to be useful in assessing treatment response and clinical follow-up of pancreatic diseases. However, most of the described practical settings were characterized by a lack of uniformity and inconsistency in reporting standards across studies. Harmonization between centers is necessary to achieve more consensus and optimization of pancreatic MRE protocols.
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11
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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] [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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12
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Wang H, Pednekar A, Tkach JA, Bridgewater KR, Trout AT, Dillman JR, Dumoulin CL. Fusing acceleration and saturation techniques with wave amplitude labeling of time-shifted zeniths MR elastography. Magn Reson Med 2020; 85:1552-1560. [PMID: 32936497 DOI: 10.1002/mrm.28488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/21/2020] [Accepted: 08/03/2020] [Indexed: 12/15/2022]
Abstract
PURPOSE To design a new 2D gradient recalled echo MR elastography (MRE) pulse sequence with inflow saturation for measuring liver stiffness in half the breath-hold time compared to standard of care (SC) 2D GRE MRE sequences. METHODS FASTWALTZ (fusing acceleration and saturation techniques with wave amplitude labeling of time-shifted zeniths) MRE employs an interleaved dual TR strategy with wave amplitude labeling and compressed SENSE undersampling to reduce breath-hold time while incorporating inflow saturation to suppress flow artifacts. The sequence was implemented and compared with SC MRE both in phantoms and in vivo in 5 asymptomatic volunteers. Stiffness values, region of interest size, and breath-hold times were compared between sequences. RESULTS Stiffness values were comparable between FASTWALTZ and SC MRE for both phantoms and in-vivo data. In volunteers, the group mean stiffness values at 60 Hz and region of interest size were 1.96 ± 0.30 kilopascals and 2279 ± 516 mm2 for SC MRE, and 1.95 ± 0.29 kilopascals and 2061 ± 464 mm2 for FASTWALTZ. Breath-hold duration for FASTWALTZ was 6.3 s compared to 13.3 s for SC MRE. CONCLUSION FASTWALTZ provides comparable stiffness values in half the breath-hold time compared to SC MRE and may have clinical benefits in patients with limited breath-holding capacity.
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Affiliation(s)
- Hui Wang
- MR Clinical Science, Philips, Cincinnati, Ohio, USA.,Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Amol Pednekar
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jean A Tkach
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Kaley R Bridgewater
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Andrew T Trout
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Jonathan R Dillman
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Charles L Dumoulin
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
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13
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Hou Z, Okamoto RJ, Bayly PV. Shear Wave Propagation and Estimation of Material Parameters in a Nonlinear, Fibrous Material. J Biomech Eng 2020; 142:051010. [PMID: 31513702 PMCID: PMC7104764 DOI: 10.1115/1.4044504] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/18/2019] [Indexed: 11/08/2022]
Abstract
This paper describes the propagation of shear waves in a Holzapfel-Gasser-Ogden (HGO) material and investigates the potential of magnetic resonance elastography (MRE) for estimating parameters of the HGO material model from experimental data. In most MRE studies the behavior of the material is assumed to be governed by linear, isotropic elasticity or viscoelasticity. In contrast, biological tissue is often nonlinear and anisotropic with a fibrous structure. In such materials, application of a quasi-static deformation (predeformation) plays an important role in shear wave propagation. Closed form expressions for shear wave speeds in an HGO material with a single family of fibers were found in a reference (undeformed) configuration and after imposed predeformations. These analytical expressions show that shear wave speeds are affected by the parameters (μ0, k1, k2, κ) of the HGO model and by the direction and amplitude of the predeformations. Simulations of corresponding finite element (FE) models confirm the predicted influence of HGO model parameters on speeds of shear waves with specific polarization and propagation directions. Importantly, the dependence of wave speeds on the parameters of the HGO model and imposed deformations could ultimately allow the noninvasive estimation of material parameters in vivo from experimental shear wave image data.
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Affiliation(s)
- Zuoxian Hou
- Department of Mechanical Engineering and Materials Science,
Washington University, St. Louis, MO,
63130 e-mail:
| | - Ruth J. Okamoto
- Department of Mechanical Engineering and Materials Science,
Washington University, St. Louis, MO
63130 e-mail:
| | - Philip V. Bayly
- Department of Mechanical Engineering and Materials Science,
Washington University, St. Louis, MO
63130 e-mail:
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14
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Majeed W, Kalra P, Kolipaka A. Simultaneous multislice rapid magnetic resonance elastography of the liver. NMR IN BIOMEDICINE 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] [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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15
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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 IN BIOMEDICINE 2019; 32:e4141. [PMID: 31329347 PMCID: PMC6817380 DOI: 10.1002/nbm.4141] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [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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16
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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] [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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17
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Comparison of Standard Breath-Held, Free-Breathing, and Compressed Sensing 2D Gradient-Recalled Echo MR Elastography Techniques for Evaluating Liver Stiffness. AJR Am J Roentgenol 2018; 211:W279-W287. [DOI: 10.2214/ajr.18.19761] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Neumann W, Bichert A, Fleischhauer J, Stern A, Figuli R, Wilhelm M, Schad LR, Zöllner FG. A novel 3D printed mechanical actuator using centrifugal force for magnetic resonance elastography: Initial results in an anthropomorphic prostate phantom. PLoS One 2018; 13:e0205442. [PMID: 30296308 PMCID: PMC6175527 DOI: 10.1371/journal.pone.0205442] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/25/2018] [Indexed: 12/12/2022] Open
Abstract
This work demonstrates a new method for the generation of mechanical shear wave during magnetic resonance elastography (MRE) that creates greater forces at higher vibrational frequencies as opposed to conventionally used pneumatic transducers. We developed an MR-compatible pneumatic turbine with an eccentric mass that creates a sinusoidal centrifugal force. The turbine was assessed with respect to its technical parameters and evaluated for MRE on a custom-made anthropomorphic prostate phantom. The silicone-based tissue-mimicking materials of the phantom were selected with regard to their complex shear moduli examined by rheometric testing. The tissue-mimicking materials closely matched human soft tissue elasticity values with a complex shear modulus ranging from 3.21 kPa to 7.29 kPa. We acquired MRE images on this phantom at 3 T with actuation frequencies of 50, 60 Hz, 70 Hz, and 80 Hz. The turbine generated vibrational wave amplitudes sufficiently large to entirely penetrate the phantoms during the feasibility study. Increased wave length in the stiffer inclusions compared to softer background material were detected. Our initial results suggest that silicone-based phantoms are useful for the evaluation of elasticities during MRE. Furthermore, our turbine seems suitable for the mechanical assessment of soft tissue during MRE.
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Affiliation(s)
- Wiebke Neumann
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Andreas Bichert
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Jonas Fleischhauer
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Antonia Stern
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Roxana Figuli
- Institute for Chemical Technology and Polymer Chemistry of Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Manfred Wilhelm
- Institute for Chemical Technology and Polymer Chemistry of Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Lothar R. Schad
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank G. Zöllner
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Garteiser P, Doblas S, Van Beers BE. Magnetic resonance elastography of liver and spleen: Methods and applications. NMR IN BIOMEDICINE 2018; 31:e3891. [PMID: 29369503 DOI: 10.1002/nbm.3891] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/16/2017] [Accepted: 12/04/2017] [Indexed: 05/06/2023]
Abstract
The viscoelastic properties of the liver and spleen can be assessed with magnetic resonance elastography (MRE). Several actuators, MRI acquisition sequences and reconstruction algorithms have been proposed for this purpose. Reproducible results are obtained, especially when the examination is performed in standard conditions with the patient fasting. Accurate staging of liver fibrosis can be obtained by measuring liver stiffness or elasticity with MRE. Moreover, emerging evidence shows that assessing the tissue viscous parameters with MRE is useful for characterizing liver inflammation, non-alcoholic steatohepatitis, hepatic congestion, portal hypertension, and hepatic tumors. Further advances such as multifrequency acquisitions and compression-sensitive MRE may provide novel quantitative markers of hepatic and splenic mechanical properties that may improve the diagnosis of hepatic and splenic diseases.
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Affiliation(s)
- Philippe Garteiser
- Laboratory of Imaging Biomarkers, Center of Research on Inflammation, UMR 1149 INSERM-University Paris Diderot, Paris, France
| | - Sabrina Doblas
- Laboratory of Imaging Biomarkers, Center of Research on Inflammation, UMR 1149 INSERM-University Paris Diderot, Paris, France
| | - Bernard E Van Beers
- Laboratory of Imaging Biomarkers, Center of Research on Inflammation, UMR 1149 INSERM-University Paris Diderot, Paris, France
- Department of Radiology, Beaujon University Hospital Paris Nord, Clichy, France
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Miller R, Kolipaka A, Nash MP, Young AA. Relative identifiability of anisotropic properties from magnetic resonance elastography. NMR IN BIOMEDICINE 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] [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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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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22
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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] [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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Liver MR Elastography at 3 T: Agreement Across Pulse Sequences and Effect of Liver R2* on Image Quality. AJR Am J Roentgenol 2018; 211:588-594. [DOI: 10.2214/ajr.17.19288] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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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 PMCID: PMC5980673 DOI: 10.1002/mrm.27083] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 12/08/2017] [Accepted: 12/18/2017] [Indexed: 02/06/2023]
Abstract
Purpose Magnetic resonance elastography (MRE) is a noninvasive tool for quantifying soft tissue stiffness. MRE has been adopted as a clinical method for staging liver fibrosis. The application of liver MRE, however, requires multiple lengthy breath holds. We propose a new data acquisition and processing method to reduce MRE scan time. Theory and Methods A Bayesian image reconstruction method that utilizes transform sparsity and magnitude consistency across different phase offsets to recover images from highly undersampled data is proposed. The method is validated using retrospectively downsampled phantom data and prospectively downsampled in vivo data (n=86). Results The proposed technique allows accurate quantification of mean liver stiffness up to an acceleration factor of R=6, enabling acquisition of a slice in 4.3 seconds. Bland Altman analysis indicates that the proposed technique (R=6) has a bias of −0.04 kPa and limits of agreement of –0.36 to +0.28 kPa when compared to traditional GRAPPA reconstruction (R=1.4). Conclusion By exploiting transform sparsity and magnitude consistency, accurate quantification of mean stiffness in the liver can be obtained at acceleration rate of up to R=6. This potentially enables collection of three to four liver slices, as per clinical protocol, within a single breath hold.
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Affiliation(s)
- Christopher Ebersole
- Department of Electrical and Computer Engineering, The Ohio State University
- Department of Radiology, The Ohio State University
| | - Rizwan Ahmad
- Department of Biomedical Engineering, The Ohio State University
| | - Adam V. Rich
- Department of Electrical and Computer Engineering, The Ohio State University
| | - Lee C. Potter
- Department of Electrical and Computer Engineering, The Ohio State University
| | - Huiming Dong
- Department of Radiology, The Ohio State University
- Department of Biomedical Engineering, The Ohio State University
| | - Arunark Kolipaka
- Department of Electrical and Computer Engineering, The Ohio State University
- Department of Radiology, The Ohio State University
- Department of Biomedical Engineering, The Ohio State University
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Bae JS, Lee JM, Park SJ, Lee KB, Han JK. Magnetic resonance elastography of healthy livers at 3.0 T: Normal liver stiffness measured by SE-EPI and GRE. Eur J Radiol 2018; 107:46-53. [PMID: 30292272 DOI: 10.1016/j.ejrad.2018.08.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 07/10/2018] [Accepted: 08/13/2018] [Indexed: 02/07/2023]
Abstract
PURPOSE To determine the normal liver stiffness values using magnetic resonance elastography (MRE) at 3.0 T and to compare spin-echo echo-planar imaging (SE-EPI) and gradient-recalled-echo (GRE) MRE. MATERIALS AND METHODS This retrospective study included 54 living liver donors who had normal clinical and pathological results without underlying liver disease and underwent MRE using both SE-EPI and GRE at 3.0 T. Two radiologists placed four or six freehand regions of interest (ROI) on the elastograms and measured liver stiffness as well as the area of ROIs. The mean liver stiffness values and area of ROIs were compared between genders, among age groups, and between groups of different body mass indexes using the t-test and one-way analysis of variance, respectively. Interobserver agreement was analyzed using intraclass correlation coefficient. The mean liver stiffness values and area of ROIs were compared between SE-EPI and GRE using the paired t-test and Bland-Altman analysis. RESULTS The liver stiffness values in living liver donors ranged from 1.52 to 3.12 kPa on SE-EPI and 1.51 to 2.67 kPa on GRE. The mean liver stiffness values did not differ significantly according to the gender, age, and body mass index. Measurement of liver stiffness using MRE showed excellent interobserver agreement on both pulse sequences. The mean value of liver stiffness was higher on SE-EPI (2.14 ± 0.33 kPa) than on GRE (2.06 ± 0.25 kPa), and the difference was statistically significant (P < 0.05). The mean area of ROI was significantly larger with GRE (3387 mm2) than with SE-EPI (2691 mm2) (P < 0.05). CONCLUSIONS The mean liver stiffness values in living donors measured by SE-EPI and GRE were not affected by gender, age, or body mass index and showed excellent interobserver agreement. The area of ROI was larger with GRE than with SE-EPI.
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Affiliation(s)
- Jae Seok Bae
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Jeong Min Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Sae-Jin Park
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Kyung Bun Lee
- Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Joon Koo Han
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea; Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
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26
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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: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [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] [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] [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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Murphy IG, Graves MJ, Reid S, Patterson AJ, Patterson I, Priest AN, Lomas DJ. Comparison of breath-hold, respiratory navigated and free-breathing MR elastography of the liver. Magn Reson Imaging 2017; 37:46-50. [DOI: 10.1016/j.mri.2016.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/13/2016] [Accepted: 10/05/2016] [Indexed: 12/13/2022]
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Editorial: A New Spin on Magnetic Resonance Elastography. Am J Gastroenterol 2016; 111:834-7. [PMID: 27249983 DOI: 10.1038/ajg.2016.134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 03/07/2016] [Indexed: 12/11/2022]
Abstract
The development of hepatic fibrosis is the hallmark of liver disease progression. Identifying fibrosis across the spectrum, from early stages to cirrhosis has become a major unmet need. Newer imaging techniques that measure liver elastography (stiffness) as a surrogate of fibrosis seem to outperform serum tests. The current study compares two-dimensional (2D) gradient-recalled echo magnetic resonance elastography (MRE) to three-dimensional (3D) spin-echo echo-planar imaging MRE. 3D-SE-EPI MRE was able to image more liver volume in less time with fewer technical failures. The current study demonstrates that 3D-SE-EPI MRE appears marginally superior to 2D-GRE and may evolve into the new gold standard.
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Chakouch MK, Charleux F, Bensamoun SF. Quantifying the Elastic Property of Nine Thigh Muscles Using Magnetic Resonance Elastography. PLoS One 2015; 10:e0138873. [PMID: 26397730 PMCID: PMC4580449 DOI: 10.1371/journal.pone.0138873] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 09/05/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Pathologies of the muscles can manifest different physiological and functional changes. To adapt treatment, it is necessary to characterize the elastic property (shear modulus) of single muscles. Previous studies have used magnetic resonance elastography (MRE), a technique based on MRI technology, to analyze the mechanical behavior of healthy and pathological muscles. The purpose of this study was to develop protocols using MRE to determine the shear modulus of nine thigh muscles at rest. METHODS Twenty-nine healthy volunteers (mean age = 26 ± 3.41 years) with no muscle abnormalities underwent MRE tests (1.5 T MRI). Five MRE protocols were developed to quantify the shear moduli of the nine following thigh muscles at rest: rectus femoris (RF), vastus medialis (VM), vastus intermedius (VI), vastus lateralis (VL), sartorius (Sr), gracilis (Gr), semimembranosus (SM), semitendinosus (ST), and biceps (BC). In addition, the shear modulus of the subcutaneous adipose tissue was analyzed. RESULTS The gracilis, sartorius, and semitendinosus muscles revealed a significantly higher shear modulus (μ_Gr = 6.15 ± 0.45 kPa, μ_ Sr = 5.15 ± 0.19 kPa, and μ_ ST = 5.32 ± 0.10 kPa, respectively) compared to other tissues (from μ_ RF = 3.91 ± 0.16 kPa to μ_VI = 4.23 ± 0.25 kPa). Subcutaneous adipose tissue had the lowest value (μ_adipose tissue = 3.04 ± 0.12 kPa) of all the tissues tested. CONCLUSION The different elasticities measured between the tissues may be due to variations in the muscles' physiological and architectural compositions. Thus, the present protocol could be applied to injured muscles to identify their behavior of elastic property. Previous studies on muscle pathology found that quantification of the shear modulus could be used as a clinical protocol to identify pathological muscles and to follow-up effects of treatments and therapies. These data could also be used for modelling purposes.
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Affiliation(s)
- Mashhour K. Chakouch
- Biomechanics and Bioengineering Laboratory, UMR CNRS 7338, Sorbonne University, Université de Technologie de Compiègne, Compiègne, France
| | | | - Sabine F. Bensamoun
- Biomechanics and Bioengineering Laboratory, UMR CNRS 7338, Sorbonne University, Université de Technologie de Compiègne, Compiègne, France
- * E-mail:
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Yeom SK, Lee CH, Cha SH, Park CM. Prediction of liver cirrhosis, using diagnostic imaging tools. World J Hepatol 2015; 7:2069-2079. [PMID: 26301049 PMCID: PMC4539400 DOI: 10.4254/wjh.v7.i17.2069] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/15/2015] [Accepted: 08/11/2015] [Indexed: 02/06/2023] Open
Abstract
Early diagnosis of liver cirrhosis is important. Ultrasound-guided liver biopsy is the gold standard for diagnosis of liver cirrhosis. However, its invasiveness and sampling bias limit the applicability of the method. Basic imaging for the diagnosis of liver cirrhosis has developed over the last few decades, enabling early detection of morphological changes of the liver by ultrasonography (US), computed tomography, and magnetic resonance imaging (MRI). They are also accurate diagnostic methods for advanced liver cirrhosis, for which early diagnosis is difficult. There are a number of ways to compensate for this difficulty, including texture analysis to more closely identify the homogeneity of hepatic parenchyma, elastography to measure the stiffness and elasticity of the liver, and perfusion studies to determine the blood flow volume, transit time, and velocity. Amongst these methods, elastography using US and MRI was found to be slightly easier, faster, and able to provide an accurate diagnosis. Early diagnosis of liver cirrhosis using MRI or US elastography is therefore a realistic alternative, but further research is still needed.
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