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Wang L, Chen W, Qian Y, So TY. Repeatability of quantitative T1rho magnetic resonance imaging in normal brain tissues at 3.0T. Phys Med 2023; 112:102641. [PMID: 37480710 DOI: 10.1016/j.ejmp.2023.102641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/21/2023] [Accepted: 07/05/2023] [Indexed: 07/24/2023] Open
Abstract
PURPOSE T1rho imaging is a promising MRI technique for imaging of brain disease. This study aimed to assess the repeatability of quantitative T1rho imaging in the normal brain grey and white matter. METHODS The study prospectively recruited 30 healthy volunteers without a history of neurological diseases or brain injury, and T1rho was performed and quantified from three imaging sessions. Repeat measures analysis of variance (ANOVA) and within-subject coefficients of variation (wCoV) was used to detect differences in T1rho values between the three scans. RESULTS The results showed low wCoVs of less than 4.3% (range 0.92-4.27%) across all the brain structures. No significant differences were observed in T1rho measurement between the three scans (p > 0.05). The amygdala and hippocampus showed the highest T1rho values of 91.79 ± 2.55 msec and 91.07 ± 2.11 msec respectively, and the palladium and putamen had the lowest values of 67.60 ± 1.84 msec and 71.83 ± 1.85 msec respectively. CONCLUSION T1rho shows high test-retest repeatability for whole brain imaging in serial imaging sessions, indicating it to be a reliable sequence for quantitative brain imaging.
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Affiliation(s)
- Lei Wang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region
| | - Yurui Qian
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region
| | - Tiffany Y So
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region.
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Tolkkinen K, Mailhiot SE, Selent A, Mankinen O, Henschel H, Nieminen MT, Hanni M, Kantola AM, Liimatainen T, Telkki VV. SPICY: a method for single scan rotating frame relaxometry. Phys Chem Chem Phys 2023; 25:13164-13169. [PMID: 37129427 PMCID: PMC10171246 DOI: 10.1039/d2cp05988f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
T 1ρ is an NMR relaxation mode that is sensitive to low frequency molecular motions, making it an especially valuable tool in biomolecular research. Here, we introduce a new method, SPICY, for measuring T1ρ relaxation times. In contrast to conventional T1ρ experiments, in which the sequence is repeated many times to determine the T1ρ time, the SPICY sequence allows determination of T1ρ within a single scan, shortening the experiment time remarkably. We demonstrate the method using 1H T1ρ relaxation dispersion experiments. Additionally, we combine the sequence with spatial encoding to produce 1D images in a single scan. We show that T1ρ relaxation times obtained using the single scan approach are in good agreement with those obtained using the traditional experiments.
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Affiliation(s)
| | | | - Anne Selent
- NMR Research Unit, University of Oulu, Oulu, Finland.
| | - Otto Mankinen
- NMR Research Unit, University of Oulu, Oulu, Finland.
| | - Henning Henschel
- Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Miika T Nieminen
- Research Unit of Health Sciences and Technology, University of Oulu, Oulu, Finland
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Matti Hanni
- Research Unit of Health Sciences and Technology, University of Oulu, Oulu, Finland
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Anu M Kantola
- NMR Research Unit, University of Oulu, Oulu, Finland.
| | - Timo Liimatainen
- Research Unit of Health Sciences and Technology, University of Oulu, Oulu, Finland
- Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
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3
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Zu Z, Adelnia F, Harkins K, Wang F, Ostenson J, Gore JC. Correction of errors in estimates of T 1ρ at low spin-lock amplitudes in the presence of B 0 and B 1 inhomogeneities. NMR IN BIOMEDICINE 2023; 36:e4951. [PMID: 37070215 PMCID: PMC10619883 DOI: 10.1002/nbm.4951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/06/2023]
Abstract
Relaxation rates R1ρ in the rotating frame measured by spin-lock methods at very low locking amplitudes (≤ 100 Hz) are sensitive to the effects of water diffusion in intrinsic gradients and may provide information on tissue microvasculature, but accurate estimates are challenging in the presence of B0 and B1 inhomogeneities. Although composite pulse preparations have been developed to compensate for nonuniform fields, the transverse magnetization comprises different components and the spin-lock signals measured do not decay exponentially as a function of locking interval at low locking amplitudes. For example, during a typical preparation sequence, some of the magnetization in the transverse plane is nutated to the Z-axis and later tipped back, and so does not experience R1ρ relaxation. As a result, if the spin-lock signals are fit to a monoexponential decay with locking interval, there are residual errors in quantitative estimates of relaxation rates R1ρ and their dispersion with weak locking fields. We developed an approximate theoretical analysis to model the behaviors of the different components of the magnetization, which provides a means to correct these errors. The performance of this correction approach was evaluated both through numerical simulations and on human brain images at 3 T, and compared with a previous correction method using matrix multiplication. Our correction approach has better performance than the previous method at low locking amplitudes. Through careful shimming, the correction approach can be applied in studies using low spin-lock amplitudes to assess the contribution of diffusion to R1ρ dispersion and to derive estimates of microvascular sizes and spacings. The results of imaging eight healthy subjects suggest that R1ρ dispersion in human brain at low locking fields arises from diffusion among inhomogeneities that generate intrinsic gradients on a scale of capillaries (~7.4 ± 0.5 μm).
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Affiliation(s)
- Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Fatemeh Adelnia
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kevin Harkins
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Feng Wang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jason Ostenson
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - John C. Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Deparment of Physics and Astronomy, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Pang Y. A self-compensated spin-locking scheme for quantitative R 1ρ dispersion MR imaging in ordered tissues. Magn Reson Imaging 2022; 94:112-118. [PMID: 36181969 DOI: 10.1016/j.mri.2022.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/01/2022] [Accepted: 09/25/2022] [Indexed: 11/24/2022]
Abstract
PURPOSE To propose a self-compensated spin-locking (SL) method for quantitative R1ρ dispersion imaging in ordered tissues. METHODS Two pairs of antiphase rotary-echo SL pulses were proposed in a new scheme with each pairs sandwiching one refocusing RF pulse. This proposed SL method was evaluated by Bloch simulations and experimental studies relative to three prior schemes. Quantitative R1ρR dispersion imaging studies with constant SL duration (TSL = 40 ms) were carried out on an agarose (1-4% w/v) phantom and one in vivo human knee at 3 T, using six SL RF strengths ranging from 50 to 1000 Hz. The performances of these SL schemes were characterized with an average coefficient of variation (CV) of the signal intensities in agarose gels and the sum of squared errors (SSE) for quantifying in vivo R1ρ dispersion of the femoral and tibial cartilage. RESULTS The simulations demonstrate that the proposed SL scheme was less prone to B0 and B1 field inhomogeneities. This theoretical prediction was supported by fewer image banding artifacts and less signal fluctuation signified by a reduced CV (%) on the phantom without R1ρ dispersion (i.e., 4.04 ± 1.36 vs. 18.87 ± 4.46 or 6.66 ± 2.92 or 5.71 ± 2.05 for others), and further by mostly decreased SSE (*10-3) for characterizing R1ρ dispersion of the femoral (i.e., 0.3 vs. 1.2 or 0.4 or 0.1) and tibial (i.e., 0.4 vs. 7.2 or 3.2 or 2.8) cartilage. CONCLUSION The proposed SL scheme is less sensitive to B0 and B1 field artifacts for a wide range of SL RF strengths and thus more suitable for quantitative R1ρ dispersion imaging in ordered tissues.
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Affiliation(s)
- Yuxi Pang
- Department of Radiology, University of Michigan, Ann Arbor, MI, USA.
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Qi H, Lv Z, Hu J, Xu J, Botnar R, Prieto C, Hu P. Accelerated 3D free-breathing high-resolution myocardial T 1ρ mapping at 3 Tesla. Magn Reson Med 2022; 88:2520-2531. [PMID: 36054715 DOI: 10.1002/mrm.29417] [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: 06/03/2022] [Revised: 07/18/2022] [Accepted: 07/27/2022] [Indexed: 11/08/2022]
Abstract
PURPOSE To develop a fast free-breathing whole-heart high-resolution myocardial T1ρ mapping technique with robust spin-lock preparation that can be performed at 3 Tesla. METHODS An adiabatically excited continuous-wave spin-lock module, insensitive to field inhomogeneities, was implemented with an electrocardiogram-triggered low-flip angle spoiled gradient echo sequence with variable-density 3D Cartesian undersampling at a 3 Tesla whole-body scanner. A saturation pulse was performed at the beginning of each cardiac cycle to null the magnetization before T1ρ preparation. Multiple T1ρ -weighted images were acquired with T1ρ preparations with different spin-lock times in an interleaved fashion. Respiratory self-gating approach was adopted along with localized autofocus to enable 3D translational motion correction of the data acquired in each heartbeat. After motion correction, multi-contrast locally low-rank reconstruction was performed to reduce undersampling artifacts. The accuracy and feasibility of the 3D T1ρ mapping technique was investigated in phantoms and in vivo in 10 healthy subjects compared with the 2D T1ρ mapping. RESULTS The 3D T1ρ mapping technique provided similar phantom T1ρ measurements in the range of 25-120 ms to the 2D T1ρ mapping reference over a wide range of simulated heart rates. With the robust adiabatically excited continuous-wave spin-lock preparation, good quality 2D and 3D in vivo T1ρ -weighted images and T1ρ maps were obtained. Myocardial T1ρ values with the 3D T1ρ mapping were slightly longer than 2D breath-hold measurements (septal T1ρ : 52.7 ± 1.4 ms vs. 50.2 ± 1.8 ms, P < 0.01). CONCLUSION A fast 3D free-breathing whole-heart T1ρ mapping technique was proposed for T1ρ quantification at 3 T with isotropic spatial resolution (2 mm3 ) and short scan time of ∼4.5 min.
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Affiliation(s)
- Haikun Qi
- School of Biomedical Engineering, ShanghaiTech University, Shanghai, People's Republic of China
| | - Zhenfeng Lv
- School of Biomedical Engineering, ShanghaiTech University, Shanghai, People's Republic of China
| | - Junpu Hu
- United Imaging Healthcare, Shanghai, People's Republic of China
| | - Jian Xu
- UIH America, Inc., Houston, Texas
| | - René Botnar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile.,Millennium Institute for Intelligent Healthcare Engineering, Santiago, Chile
| | - Claudia Prieto
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Santiago, Chile.,Millennium Institute for Intelligent Healthcare Engineering, Santiago, Chile
| | - Peng Hu
- School of Biomedical Engineering, ShanghaiTech University, Shanghai, People's Republic of China
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Abstract
BACKGROUND Blood pressure variability (BPV) has been linked with cognitive impairment and dementia. However, the pathophysiological mechanisms by which BPV affects cognition are unclear. This systematic review aims to assess the links between different BPV measures and white and grey matter structures. METHODS AND RESULTS The following databases were searched from inception through to January 2021; EMBASE, MEDLINE, EMCARE and SCOPUS. Studies that reported on the relationship between within-individual BPV (short, medium or long-term variability) or a circadian blood pressure (BP) measurement and MRI assessed brain structures were included. Overall, 20 studies met the criteria and were included, of which 11 studies looked at short-term BPV, eight articles investigated visit-to-visit BPV and one study looked at a compositional BPV measurement. Due to heterogeneity in study samples, meta-analysis was not possible. Across the included studies, associations between MRI indices and BP dipping patterns were mixed; higher long-term BPV and higher sleep systolic BPV was found to be associated with lower whole brain volume and hippocampal volume. CONCLUSION Increased BPV, in particular systolic long-term and systolic night-time BPV, appears to be associated with lower brain volume and hippocampal volume. This highlights the adverse effect that increased BPV has upon the brain, potentially contributing to cognitive decline, including dementia, in late-life.
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Qian Y, Hou J, Jiang B, Wong VWS, Lee J, Chan Q, Wang Y, Chu WCW, Chen W. Characterization and correction of the effects of hepatic iron on T 1ρ relaxation in the liver at 3.0T. Magn Reson Med 2022; 88:1828-1839. [PMID: 35608236 DOI: 10.1002/mrm.29310] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 04/13/2022] [Accepted: 05/02/2022] [Indexed: 11/10/2022]
Abstract
PURPOSE Quantitative T1ρ imaging is an emerging technique to assess the biochemical properties of tissues. In this paper, we report our observation that liver iron content (LIC) affects T1ρ quantification of the liver at 3.0T field strength and develop a method to correct the effect of LIC. THEORY AND METHODS On-resonance R1ρ (1/T1ρ ) is mainly affected by the intrinsic R2 (1/T2 ), which is influenced by LIC. As on-resonance R1ρ is closely related to the Carr-Purcell-Meiboom-Gill (CPMG) R2 , and because the calibration between CPMG R2 and LIC has been reported at 1.5T, a correction method was proposed to correct the R2 contribution to the R1ρ . The correction coefficient was obtained from the calibration results and related transformed factors. To compensate for the difference between CPMG R2 and R1ρ , a scaling factor was determined using the values of CPMG R2 and R1ρ , obtained simultaneously from a single breath-hold from volunteers. The livers of 110 subjects were scanned to validate the correction method. RESULTS LIC was significantly correlated with R1ρ in the liver. However, when the proposed correction method was applied to R1ρ , LIC and the iron-corrected R1ρ were not significantly correlated. CONCLUSION LIC can affect T1ρ in the liver. We developed an iron-correction method for the quantification of T1ρ in the liver at 3.0T.
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Affiliation(s)
- Yurui Qian
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Hong Kong, China
| | - Jian Hou
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Hong Kong, China
| | - Baiyan Jiang
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Hong Kong, China.,Illuminatio Medical Technology Limited, Hong Kong, China
| | - Vincent Wai-Sun Wong
- Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Hong Kong, China
| | - Jack Lee
- Clinical Trials and Biostatistics Lab, CUHK Shenzhen Research Institute, Shenzhen, China.,Division of Biostatistics, Jockey Club School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | | | - Yixiang Wang
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Hong Kong, China
| | - Winnie Chiu-Wing Chu
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Hong Kong, China
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Hong Kong, China
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Saito S, Arihara N, Sawaya R, Morimoto-Ishikawa D, Ueda J. Metabolites Alterations and Liver Injury in Hepatic Encephalopathy Models Evaluated by Use of 7T-MRI. Metabolites 2022; 12:metabo12050396. [PMID: 35629900 PMCID: PMC9147964 DOI: 10.3390/metabo12050396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/22/2022] [Accepted: 04/26/2022] [Indexed: 11/16/2022] Open
Abstract
This study is to observe a thioacetamide (TAA) administered Hepatic encephalopathy (HE) model rats at three and ten days after TAA administration using liver MRI and brain MR Spectroscopy (MRS) by use of 7T-MRI. Forty-two Wistar rats (control group, n = 14) were intraperitoneally administered at 300 mg/kg (low-dose group, n = 14) or 400 mg/kg (high-dose group, n = 14) doses of TAA for induced of HE. At three days after TAA administration, glutamine (Gln) measured by MRS in high-dose and low-dose TAA groups showed significant increases in comparison to those of the control group (p < 0.05). Other metabolites measured by MRS showed no significant changes. Liver T1ρ and T2 relaxation times significantly increased three days after TAA injection compared to pre-injection. There was a correlation between Gln levels in the brain and the relaxation time of the liver. Furthermore, Gln levels and relaxation time changed depending on the TAA dose. The Gln concentration in the brain increased with the deterioration of liver function, as inferred from the prolonged relaxation time of the liver. The prolonged relaxation time of the liver corresponded with the level of Gln in the brain. Gln concentration for the alterations of brain metabolites and T1ρ relaxation time for the assessment of liver damage are useful markers for inter-organ association analysis in the HE model.
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Affiliation(s)
- Shigeyoshi Saito
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (N.A.); (R.S.); (J.U.)
- Department of Advanced Medical Technologies, National Cerebral and Cardiovascular Center Research Institute, Suita 565-0871, Japan
- Correspondence: ; Tel.: +81-6-6879-2619
| | - Narumi Arihara
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (N.A.); (R.S.); (J.U.)
| | - Reika Sawaya
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (N.A.); (R.S.); (J.U.)
| | | | - Junpei Ueda
- Department of Medical Physics and Engineering, Area of Medical Imaging Technology and Science, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita 565-0871, Japan; (N.A.); (R.S.); (J.U.)
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Arihara N, Saito S, Sawaya R, Onishi R, Tsuji K, Ohki A, Ueda J, Morimoto-Ishiwaka D. Evaluation of liver T 1rho and T 2 values in acute liver inflammation models using 7T-MRI. Magn Reson Imaging 2022; 88:20-24. [PMID: 35091025 DOI: 10.1016/j.mri.2022.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/21/2021] [Accepted: 01/22/2022] [Indexed: 12/30/2022]
Abstract
PURPOSE We measured the T 1rho and T 2 values the liver of acute liver inflammation model mice administered carbon tetrachloride (CCl 4) after 3 days and 6 days after dispensed, and we compared and examined whether each relaxation time can be used for detect acute liver inflammation. METHODS To create an acute liver inflammation model, a mixture of 0.2 ml / 100 g of CCl 4 with an equal amount of Sesame Oil was administered once intraperitoneally to C57BL / 6JJmsSlc mice (n = 15). On the 3 days and 6 days after administration, we acquired T 1rho mapping images and T 2 mapping images of the liver under respiratory synchronization using for preclinical 7T-MRI, and we measured T 1rho and T 2 values and compared statistically. RESULTS The liver T 1rho value of control mice was 33.9 ± 2.5 ms before CCl 4 administration, 43.2 ± 4.9 ms (p < 0.01) on the 3 days post CCl 4 injection, and 41.0 ± 1.2 ms (p < 0.001) on the 6 days post CCl 4 injection. The rate showed a significant increase of 27% on the 3 days after, as well as significant increase of 21% on the 6 days after. On the other hand, the liver T 2 value of control mice was 26.7 ± 1.9 ms before CCl 4 administration, 31.5 ± 3.4 ms (p < 0.05) 3 days post CCl 4 injection, and 29.0 ± 2.0 ms (p = 0.06) 6 days post CCl4 injection. The rate 3 days after CCl 4 administration showed a significant increase of 18%, after 6 days rate increased 9%, but no significant difference was confirmed compared with normal mice. CONCLUSIONS The T 1rho value changed significantly compared to the T 2 value, and a continuous change was observed even after 6 days. T 1rho mapping can diagnose acute liver inflammation.
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Affiliation(s)
- Narumi Arihara
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan
| | - Shigeyoshi Saito
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan; Department of Biomedical Imaging, National Cardiovascular and Cerebral Research Center, Suita, Osaka 565-8565, Japan.
| | - Reika Sawaya
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan
| | - Ryutarou Onishi
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan
| | - Keiho Tsuji
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan
| | - Akiko Ohki
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan; Department of Medical Technology, Kyoto University Hospital, Suita, Osaka, Japan
| | - Junpei Ueda
- Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka 560-0871, Japan; Department of Medical Technology, Osaka University Hospital, Suita, Osaka, Japan; Department of Biomedical Imaging, National Cardiovascular and Cerebral Research Center, Suita, Osaka 565-8565, Japan
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10
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Saito S. [5. Advanced Imaging Technology-T1rho-CEST Imaging]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2022; 78:95-100. [PMID: 35046227 DOI: 10.6009/jjrt.780111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shigeyoshi Saito
- Laboratory of Advanced Imaging Technology, Department of Medical Physics and Engineering, Division of Health Sciences, Osaka University Graduate School of Medicine.,Department of Advanced Medical Technology, National Cardiovascular and Cerebral Research Center
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11
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Sodoma MJ, Cole RC, Sloan TJ, Hamilton CM, Kent JD, Magnotta VA, Voss MW. Hippocampal acidity and volume are differentially associated with spatial navigation in older adults. Neuroimage 2021; 245:118682. [PMID: 34728245 PMCID: PMC8867536 DOI: 10.1016/j.neuroimage.2021.118682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/14/2021] [Accepted: 10/25/2021] [Indexed: 11/17/2022] Open
Abstract
The hippocampus is negatively affected by aging and is critical for spatial navigation. While there is evidence that wayfinding navigation tasks are especially sensitive to preclinical hippocampal deterioration, these studies have primarily used volumetric hippocampal imaging without considering microstructural properties or anatomical variation within the hippocampus. T1ρ is an MRI measure sensitive to regional pH, with longer relaxation rates reflecting acidosis as a marker of metabolic dysfunction and neuropathological burden. For the first time, we investigate how measures of wayfinding including landmark location learning and delayed memory in cognitively normal older adults (N = 84) relate to both hippocampal volume and T1ρ in the anterior and posterior hippocampus. Regression analyses revealed hippocampal volume was bilaterally related to learning, while right lateralized T1ρ was related to delayed landmark location memory and bilateral T1ρ was related to the delayed use of a cognitive map. Overall, results suggest hippocampal volume and T1ρ relaxation rate tap into distinct mechanisms involved in preclinical cognitive decline as assessed by wayfinding navigation, and laterality influenced these relationships more than the anterior-posterior longitudinal axis of the hippocampus.
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Affiliation(s)
- Matthew J Sodoma
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA.
| | - Rachel C Cole
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Department of Neurology, University of Iowa, Iowa City, IA, 52242, USA
| | - Taylor J Sloan
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Chase M Hamilton
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - James D Kent
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Department of Psychology, University of Texas at Austin, Austin, TX, 78712 USA
| | - Vincent A Magnotta
- Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA; Department of Radiology, University of Iowa, Iowa City, IA 52242, UCA; Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA; Department of Psychiatry, University of Iowa, Iowa City, IA 52242, USA; Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA 52242, USA
| | - Michelle W Voss
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA
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12
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Unger DM, Wiest R, Kiefer C, Raillard M, Dutil GF, Stein VM, Schweizer D. Neuronal current imaging: An experimental method to investigate electrical currents in dogs with idiopathic epilepsy. J Vet Intern Med 2021; 35:2828-2836. [PMID: 34623697 PMCID: PMC8692176 DOI: 10.1111/jvim.16270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 09/04/2021] [Accepted: 09/10/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The diagnosis of idiopathic epilepsy (IE) in dogs is based on exclusion of other potential causes of seizures. Recently, a novel magnetic resonance imaging (MRI) sequence that utilizes a variant of the rotary saturation approach has been suggested to detect weak transient magnetic field oscillations generated by neuronal currents in humans with epilepsy. HYPOTHESIS/OBJECTIVES Effects on the magnetic field evoked by intrinsic epileptic activity can be detected by MRI in the canine brain. As proof-of-concept, the novel MRI sequence to detect neuronal currents was applied in dogs. ANIMALS Twelve dogs with IE and 5 control dogs without a history of epileptic seizures were examined. METHODS Prospective case-control study as proof-of-concept. All dogs underwent a clinical neurological examination, scalp electroencephalography, cerebrospinal fluid analysis, and MRI. The MRI examination included a spin-locking (SL) experiment applying a low-power on-resonance radiofrequency pulse in a predefined frequency domain in the range of oscillations generated by the epileptogenic tissue. RESULTS In 11 of 12 dogs with IE, rotary saturation effects were detected by the MRI sequence. Four of 5 control dogs did not show rotary saturation effects. One control dog with a diagnosis of neuronal ceroid lipofuscinosis had SL-related effects, but did not have epileptic seizures clinically. CONCLUSIONS AND CLINICAL IMPORTANCE The proposed MRI method detected neuronal currents in dogs with epileptic seizures and represents a potential new line of research to investigate neuronal currents possibly related to IE in dogs.
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Affiliation(s)
- Daniela M Unger
- Division of Clinical Radiology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Roland Wiest
- Support Center of Advanced Neuroimaging (SCAN), Institute of Diagnostic and Interventional Neuroradiology, Inselspital Bern, University of Bern, Bern, Switzerland
| | - Claus Kiefer
- Support Center of Advanced Neuroimaging (SCAN), Institute of Diagnostic and Interventional Neuroradiology, Inselspital Bern, University of Bern, Bern, Switzerland
| | - Mathieu Raillard
- Division of Clinical Anesthesiology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Guillaume F Dutil
- Division of Clinical Neurology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Veronika M Stein
- Division of Clinical Neurology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Daniela Schweizer
- Division of Clinical Radiology, Department of Clinical Veterinary Medicine, Vetsuisse Faculty, University of Bern, Bern, Switzerland
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13
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Khattar N, Triebswetter C, Kiely M, Ferrucci L, Resnick SM, Spencer RG, Bouhrara M. Investigation of the association between cerebral iron content and myelin content in normative aging using quantitative magnetic resonance neuroimaging. Neuroimage 2021; 239:118267. [PMID: 34139358 PMCID: PMC8370037 DOI: 10.1016/j.neuroimage.2021.118267] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 12/24/2022] Open
Abstract
Myelin loss and iron accumulation are cardinal features of aging and various neurodegenerative diseases. Oligodendrocytes incorporate iron as a metabolic substrate for myelin synthesis and maintenance. An emerging hypothesis in Alzheimer’s disease research suggests that myelin breakdown releases substantial stores of iron that may accumulate, leading to further myelin breakdown and neurodegeneration. We assessed associations between iron content and myelin content in critical brain regions using quantitative magnetic resonance imaging (MRI) on a cohort of cognitively unimpaired adults ranging in age from 21 to 94 years. We measured whole-brain myelin water fraction (MWF), a surrogate of myelin content, using multicomponent relaxometry, and whole-brain iron content using susceptibility weighted imaging in all individuals. MWF was negatively associated with iron content in most brain regions evaluated indicating that lower myelin content corresponds to higher iron content. Moreover, iron content was significantly higher with advanced age in most structures, with men exhibiting a trend towards higher iron content as compared to women. Finally, relationship between MWF and age, in all brain regions investigated, suggests that brain myelination continues until middle age, followed by degeneration at older ages. This work establishes a foundation for further investigations of the etiology and sequelae of myelin breakdown and iron accumulation in neurodegeneration and may lead to new imaging markers for disease progression and treatment.
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Affiliation(s)
- Nikkita Khattar
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Curtis Triebswetter
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Matthew Kiely
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Richard G Spencer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States
| | - Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, 21224 MD, United States.
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14
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Tissue characterization using R 1rho dispersion imaging at low locking fields. Magn Reson Imaging 2021; 84:1-11. [PMID: 34052306 DOI: 10.1016/j.mri.2021.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/11/2021] [Accepted: 05/25/2021] [Indexed: 11/22/2022]
Abstract
Measurements of the variations of spin-locking relaxation rates (R1ρ) with locking field amplitude allow the derivation of quantitative parameters that describe different dynamic processes, such as slow molecular motions, chemical exchange and diffusion. In some samples, changes in R1ρ values between locking frequency 0 and 200 Hz may be dominated mainly by diffusion of water in intrinsic field gradients, while those at higher locking fields are due to exchange processes. The exchange and diffusion effects act independently of each other, as confirmed by simulation and experimentally. In tissues, the relevant intrinsic field gradients may arise from the magnetic inhomogeneities caused by microvascular blood so that R1ρ dispersion over weak locking field amplitudes (≤ 200 Hz) is affected by changes in capillary density and geometry. Here we first review the theoretical and experimental background to the interpretation of R1ρ dispersions caused by intrinsic magnetic susceptibility variations within the tissue. We then provide new empirical results of R1ρ dispersion imaging of the human brain and skeletal muscle at low locking field amplitudes for the first time and identify potential applications of R1ρ dispersion imaging in clinical studies.
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15
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Hales JB, Petty EA, Collins G, Blaser RE. Contribution of the hippocampus to performance on the traveling salesperson problem in rats. Behav Brain Res 2021; 405:113177. [PMID: 33607167 DOI: 10.1016/j.bbr.2021.113177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 01/23/2021] [Accepted: 02/08/2021] [Indexed: 11/18/2022]
Abstract
The Traveling Salesman Problem (TSP) is an optimization problem in which the subject attempts to find the shortest possible route that passes through a set of fixed locations exactly once. The TSP is used in cognitive and behavioral research to study problem solving and spatial navigation. While the TSP has been studied in some depth from this perspective, the biological mechanisms underlying the behavior have not yet been explored. The hippocampus is a structure in the brain that is known to be involved in tasks that require spatial memory. Because the TSP requires spatial problem solving, we designed the current study to determine whether the hippocampus is required to find efficient solutions to the TSP, and if so, what role the hippocampus serves. Rats were pretrained on the TSP, which involved learning to retrieve bait from targets in a variety of spatial configurations. Matched for performance, rats were then divided into two groups, receiving either a hippocampal lesion or a control sham surgery. After recovering from surgery, the rats were tested on eight new configurations. A variety of behavioral measures were recorded, including distance travelled, number of revisits, memory span, and latency. The results showed that the sham group outperformed the lesion group on most of these measures. Based on the behavioral data and histological tissue analysis of each group, we determined that the hippocampus is involved in successful performance in the TSP, particularly regarding memory for which targets have already been visited.
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Affiliation(s)
- Jena B Hales
- University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA.
| | | | - Gequasha Collins
- University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | - R E Blaser
- University of San Diego, 5998 Alcala Park, San Diego, CA 92110, USA.
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16
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Zhu Y, Liu Y, Ying L, Qiu Z, Liu Q, Jia S, Wang H, Peng X, Liu X, Zheng H, Liang D. A 4-minute solution for submillimeter whole-brain T 1ρ quantification. Magn Reson Med 2021; 85:3299-3307. [PMID: 33421224 DOI: 10.1002/mrm.28656] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/12/2022]
Abstract
PURPOSE To develop a robust, accurate, and accelerated T1ρ quantification solution for submillimeter in vivo whole-brain imaging. METHODS A multislice T1ρ mapping solution (MS-T1ρ ) was developed based on a two-acquisition scheme using turbo spin echo with RF cycling to allow for whole-brain coverage with 0.8-mm in-plane resolution. A compressed sensing-based fast imaging method, SCOPE, was used to accelerate the MS-T1ρ acquisition time to a total scan time of 3 minutes 31 seconds. A phantom experiment was conducted to assess the accuracy of MS-T1ρ by comparing the T1ρ value obtained using MS-T1ρ with the reference value obtained using the standard single-slice T1ρ mapping method. In vivo scans of 13 volunteers were acquired prospectively to validate the robustness of MS-T1ρ . RESULTS In the phantom study, the T1ρ values obtained with MS-T1ρ were in good agreement with the reference T1ρ values (R2 = 0.9991) and showed high consistency throughout all slices (coefficient of variation = 2.2 ± 2.43%). In the in vivo experiments, T1ρ maps were successfully acquired for all volunteers with no visually noticeable artifacts. There was no significant difference in T1ρ values between MS-T1ρ acquisitions and fully sampled acquisitions for all brain tissues (p-value > .05). In the intraclass correlation coefficient and Bland-Altman analyses, the accelerated T1ρ measurements show moderate to good agreement to the fully sampled reference values. CONCLUSION The proposed MS-T1ρ solution allows for high-resolution whole-brain T1ρ mapping within 4 minutes and may provide a potential tool for investigating neural diseases.
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Affiliation(s)
- Yanjie Zhu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Yuanyuan Liu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Leslie Ying
- Department of Biomedical Engineering and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, 14260, USA
| | - Zhilang Qiu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Qiegen Liu
- Department of Electronic Information Engineering, Nanchang University, Nanchang, Jiangxi, 330031, China
| | - Sen Jia
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Haifeng Wang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Xi Peng
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, 55905, USA
| | - Xin Liu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
| | - Dong Liang
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China
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17
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Ai QYH, Zhang H, Jiang B, So TY, Mo FKF, Qamar S, Chen W, King AD. Test-retest repeatability of T1rho (T1ρ) MR imaging in the head and neck. Eur J Radiol 2020; 135:109489. [PMID: 33395595 DOI: 10.1016/j.ejrad.2020.109489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 12/27/2022]
Abstract
PURPOSE T1rho imaging is a new quantitative MRI sequence for head and neck cancer and the repeatability for this region is unknown. This study aimed to evaluate the repeatability of quantitative T1rho imaging in the head and neck. MATERIALS AND METHODS T1rho imaging of the head and neck was prospectively performed in 15 healthy participants on three occasions. Scan 1 and 2 were performed with a time interval of 30 minutes (intra-session) and scan 3 was performed 14 days later (inter-session). T1rho values for normal tissues (parotid glands, palatine tonsils, pterygoid muscles, and tongue) were obtained on each scan. Intra-class coefficients (ICCs), within-subject coefficient of variances (wCoVs), and repeatability coefficient (RCs) of the intra-session scan (scan 1 vs 2) and inter-session scan (scan 1 vs 3) for the normal tissues were calculated. RESULTS The ICCs of T1rho values for normal tissues were almost perfect (0.83-0.97) for intra-session scans and were substantial (0.71-0.80) for inter-session scans. The wCoVs showed a small range (2.46%-3.30%) for intra-session scans, and slightly greater range (3.27%-6.51%) for inter-session scan. The greatest and lowest wCoVs of T1rho were found in the parotid gland and muscles, respectively. The T1rho RCs varied for all tissues between intra- and inter- sessions, and the greatest RC of 10.07 msec was observed for parotid gland on inter-session scan. CONCLUSION T1rho imaging is a repeatable quantitative MRI sequence in the head and neck but variances of T1rho values among tissues should be take into account during analysis.
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Affiliation(s)
- Qi Yong H Ai
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong.
| | - Huimin Zhang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Baiyan Jiang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Tiffany Y So
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Frankie K F Mo
- Department of Clinical Oncology, State Key Laboratory of Translational Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Sahrish Qamar
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
| | - Ann D King
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
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18
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Ai QYH, Chen W, So TY, Lam WKJ, Jiang B, Poon DMC, Qamar S, Mo FKF, Blu T, Chan Q, Ma BBY, Hui EP, Chan KCA, King AD. Quantitative T1ρ MRI of the Head and Neck Discriminates Carcinoma and Benign Hyperplasia in the Nasopharynx. AJNR Am J Neuroradiol 2020; 41:2339-2344. [PMID: 33122214 DOI: 10.3174/ajnr.a6828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 08/07/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE T1ρ imaging is a new quantitative MR imaging pulse sequence with the potential to discriminate between malignant and benign tissue. In this study, we evaluated the capability of T1ρ imaging to characterize tissue by applying T1ρ imaging to malignant and benign tissue in the nasopharynx and to normal tissue in the head and neck. MATERIALS AND METHODS Participants with undifferentiated nasopharyngeal carcinoma and benign hyperplasia of the nasopharynx prospectively underwent T1ρ imaging. T1ρ measurements obtained from the histogram analysis for nasopharyngeal carcinoma in 43 participants were compared with those for benign hyperplasia and for normal tissue (brain, muscle, and parotid glands) in 41 participants using the Mann-Whitney U test. The area under the curve of significant T1ρ measurements was calculated and compared using receiver operating characteristic analysis and the Delong test, respectively. A P < . 05 indicated statistical significance. RESULTS There were significant differences in T1ρ measurements between nasopharyngeal carcinoma and benign hyperplasia and between nasopharyngeal carcinoma and normal tissue (all, P < . 05). Compared with benign hyperplasia, nasopharyngeal carcinoma showed a lower T1ρ mean (62.14 versus 65.45 × ms), SD (12.60 versus 17.73 × ms), and skewness (0.61 versus 0.76) (all P < .05), but no difference in kurtosis (P = . 18). The T1ρ SD showed the highest area under the curve of 0.95 compared with the T1ρ mean (area under the curve = 0.72) and T1ρ skewness (area under the curve = 0.72) for discriminating nasopharyngeal carcinoma and benign hyperplasia (all, P < .05). CONCLUSIONS Quantitative T1ρ imaging has the potential to discriminate malignant from benign and normal tissue in the head and neck.
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Affiliation(s)
- Q Y H Ai
- From the Department of Imaging and Interventional Radiology (Q.Y.H.A., W.C., T.Y.S., B.J., S.Q., A.D.K.)
| | - W Chen
- From the Department of Imaging and Interventional Radiology (Q.Y.H.A., W.C., T.Y.S., B.J., S.Q., A.D.K.)
| | - T Y So
- From the Department of Imaging and Interventional Radiology (Q.Y.H.A., W.C., T.Y.S., B.J., S.Q., A.D.K.)
| | - W K J Lam
- Li Ka Shing Institute of Health Sciences (W.K.J.L., D.M.C.P., B.B.Y.M., E.P.H., K.C.A.C.).,State Key Laboratory of Translational Oncology (W.K.J.L., D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H., K.C.A.C.).,Department of Chemical Pathology (W.K.J.L., K.C.A.C.), State Key Laboratory in Oncology in South China, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, SAR
| | - B Jiang
- From the Department of Imaging and Interventional Radiology (Q.Y.H.A., W.C., T.Y.S., B.J., S.Q., A.D.K.)
| | - D M C Poon
- Li Ka Shing Institute of Health Sciences (W.K.J.L., D.M.C.P., B.B.Y.M., E.P.H., K.C.A.C.).,Department of Clinical Oncology (D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H.), State Key Laboratory in Oncology in South China, Sir Y.K. Pao Centre for Cancer, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, SAR.,State Key Laboratory of Translational Oncology (W.K.J.L., D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H., K.C.A.C.)
| | - S Qamar
- From the Department of Imaging and Interventional Radiology (Q.Y.H.A., W.C., T.Y.S., B.J., S.Q., A.D.K.)
| | - F K F Mo
- Department of Clinical Oncology (D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H.), State Key Laboratory in Oncology in South China, Sir Y.K. Pao Centre for Cancer, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, SAR.,State Key Laboratory of Translational Oncology (W.K.J.L., D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H., K.C.A.C.)
| | - T Blu
- Department of Electrical Engineering (T.B.), The Chinese University of Hong Kong, Hong Kong, SAR
| | - Q Chan
- Philips Healthcare (Q.C.), Hong Kong, SAR
| | - B B Y Ma
- Li Ka Shing Institute of Health Sciences (W.K.J.L., D.M.C.P., B.B.Y.M., E.P.H., K.C.A.C.).,Department of Clinical Oncology (D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H.), State Key Laboratory in Oncology in South China, Sir Y.K. Pao Centre for Cancer, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, SAR.,State Key Laboratory of Translational Oncology (W.K.J.L., D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H., K.C.A.C.)
| | - E P Hui
- Li Ka Shing Institute of Health Sciences (W.K.J.L., D.M.C.P., B.B.Y.M., E.P.H., K.C.A.C.).,Department of Clinical Oncology (D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H.), State Key Laboratory in Oncology in South China, Sir Y.K. Pao Centre for Cancer, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, SAR.,State Key Laboratory of Translational Oncology (W.K.J.L., D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H., K.C.A.C.)
| | - K C A Chan
- Li Ka Shing Institute of Health Sciences (W.K.J.L., D.M.C.P., B.B.Y.M., E.P.H., K.C.A.C.).,State Key Laboratory of Translational Oncology (W.K.J.L., D.M.C.P., F.K.F.M., B.B.Y.M., E.P.H., K.C.A.C.).,Department of Chemical Pathology (W.K.J.L., K.C.A.C.), State Key Laboratory in Oncology in South China, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, SAR
| | - A D King
- From the Department of Imaging and Interventional Radiology (Q.Y.H.A., W.C., T.Y.S., B.J., S.Q., A.D.K.)
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Subcortical T1-Rho MRI Abnormalities in Juvenile-Onset Huntington's Disease. Brain Sci 2020; 10:brainsci10080533. [PMID: 32784364 PMCID: PMC7463529 DOI: 10.3390/brainsci10080533] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 01/22/2023] Open
Abstract
Huntington’s disease (HD) is a fatal neurodegenerative disease caused by the expansion of cytosine-adenine-guanine (CAG) repeats in the huntingtin gene. An increased CAG repeat length is associated with an earlier disease onset. About 5% of HD cases occur under the age of 21 years, which are classified as juvenile-onset Huntington’s disease (JOHD). Our study aims to measure subcortical metabolic abnormalities in JOHD participants. T1-Rho (T1ρ) MRI was used to compare brain regions of 13 JOHD participants and 39 controls. Region-of-interest analyses were used to assess differences in quantitative T1ρ relaxation times. We found that the mean relaxation times in the caudate (p < 0.001), putamen (p < 0.001), globus pallidus (p < 0.001), and thalamus (p < 0.001) were increased in JOHD participants compared to controls. Furthermore, increased T1ρ relaxation times in these areas were significantly associated with lower volumes amongst participants in the JOHD group. These findings suggest metabolic abnormalities in brain regions previously shown to degenerate in JOHD. We also analyzed the relationships between mean regional T1ρ relaxation times and Universal Huntington’s Disease Rating Scale (UHDRS) scores. UHDRS was used to evaluate participants’ motor function, cognitive function, behavior, and functional capacity. Mean T1ρ relaxation times in the caudate (p = 0.003), putamen (p = 0.005), globus pallidus (p = 0.009), and thalamus (p = 0.015) were directly proportional to the UHDRS score. This suggests that the T1ρ relaxation time may also predict HD-related motor deficits. Our findings suggest that subcortical metabolic abnormalities drive the unique hypokinetic symptoms in JOHD.
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Johnson CP, Thedens DR, Kruger SJ, Magnotta VA. Three-Dimensional GRE T 1ρ mapping of the brain using tailored variable flip-angle scheduling. Magn Reson Med 2020; 84:1235-1249. [PMID: 32052489 DOI: 10.1002/mrm.28198] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/07/2020] [Accepted: 01/13/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE To introduce a new approach called tailored variable flip-angle (VFA) scheduling for SNR-efficient 3D T1ρ mapping of the brain using a magnetization-prepared gradient-echo sequence. METHODS Simulations were used to assess the relative SNR efficiency, quantitative accuracy, and spatial blurring of tailored VFA scheduling for T1ρ mapping of brain tissue compared with magnetization-prepared angle-modulated partitioned k-space spoiled gradient-echo snapshots (MAPSS), a state-of-the-art technique for accurate 3D gradient-echo T1ρ mapping. Simulations were also used to calculate optimal imaging parameters for tailored VFA scheduling versus MAPSS, without and with nulling of CSF. Four participants were imaged at 3T MRI to demonstrate the feasibility of tailored VFA scheduling for T1ρ mapping of the brain. Using MAPSS as a reference standard, in vivo data were used to validate the relative SNR efficiency and quantitative accuracy of the new approach. RESULTS Tailored VFA scheduling can provide a 2-fold to 4-fold gain in the SNR of the resulting T1ρ map as compared with MAPSS when using identical sequence parameters while limiting T1ρ quantification errors to 2% or less. In vivo whole-brain 3D T1ρ maps acquired with tailored VFA scheduling had superior SNR efficiency than is achievable with MAPSS, and the SNR efficiency improved with a greater number of views per segment. CONCLUSIONS Tailored VFA scheduling is an SNR-efficient GRE technique for 3D T1ρ mapping of the brain that provides increased flexibility in choice of imaging parameters compared with MAPSS, which may benefit a variety of applications.
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Affiliation(s)
- Casey P Johnson
- Veterinary Clinical Sciences Department, University of Minnesota, Saint Paul, MN, USA.,Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | | | | | - Vincent A Magnotta
- Department of Radiology, University of Iowa, Iowa City, IA, USA.,Department of Psychiatry, University of Iowa, Iowa City, IA, USA.,Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
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21
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Owusu N, Johnson CP, Kearney W, Thedens D, Wemmie J, Magnotta VA. R1ρ sensitivity to pH and other compounds at clinically accessible spin-lock fields in the presence of proteins. NMR IN BIOMEDICINE 2020; 33:e4217. [PMID: 31742802 PMCID: PMC7043777 DOI: 10.1002/nbm.4217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 09/05/2019] [Accepted: 10/07/2019] [Indexed: 05/08/2023]
Abstract
Numerous human diseases involve abnormal metabolism, and proton exchange is an effective source of magnetic resonance imaging (MRI) contrast for assessing metabolism. One MRI technique that capitalizes on proton exchange is R1 relaxation in the rotating frame (R1ρ ). Here, we investigated the sensitivity of R1ρ to various proton-exchange mechanisms at spin-lock pulses within Food and Drug Administration (FDA) safety guidelines for radiofrequency-induced heating. We systematically varied pH known to change the rate of proton exchange as well as the glucose and lysine concentrations, thus changing the number of amide, hydroxyl and amine exchangeable sites in a series of egg-white albumin phantoms. The resulting effects on quantitative relaxation time measurements of R1ρ , R1 and R2 were observed at 3 T. Using spin-lock amplitudes available for human imaging (less than 23.5 μT) at near physiologic temperatures, we found R1ρ was more sensitive to physiologic changes in pH than to changes in glucose and lysine concentrations. In addition, R1ρ was more sensitive to pH changes than R1 and R2 . Models of proton exchange fitted to the relaxation measurements suggest that amide groups were the primary source of pH sensitivity. Together, these experiments suggest an optimal spin-lock amplitude for measuring pH changes while not exceeding FDA-subject heating limitations.
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Affiliation(s)
- Nana Owusu
- Department of Radiology, University of Iowa, Iowa City, IA, USA
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
| | - Casey P. Johnson
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA
| | - William Kearney
- Department of Radiology, University of Iowa, Iowa City, IA, USA
| | - Dan Thedens
- Department of Radiology, University of Iowa, Iowa City, IA, USA
| | - John Wemmie
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
| | - Vincent A. Magnotta
- Department of Radiology, University of Iowa, Iowa City, IA, USA
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA
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22
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Ponto LLB, Magnotta VA, Menda Y, Moser DJ, Oleson JJ, Harlynn EL, DeVries SD, Wemmie JA, Schultz SK. Comparison of T 1Rho MRI, Glucose Metabolism, and Amyloid Burden Across the Cognitive Spectrum: A Pilot Study. J Neuropsychiatry Clin Neurosci 2020; 32:352-361. [PMID: 32283991 PMCID: PMC8717916 DOI: 10.1176/appi.neuropsych.19100221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The pathological cascades associated with the development of Alzheimer's disease (AD) have a common element: acidosis. T1rho MRI is a pH-sensitive measure, with higher values associated with greater neuropathological burden. The authors investigated the relationship between T1rho imaging and AD-associated pathologies as determined by available diagnostic imaging techniques. METHODS Twenty-seven participants (men, N=13, women, N=14; ages 55-90) across the cognitive spectrum (healthy control subjects [HCs] with normal cognition, N=17; participants with mild cognitive impairment [MCI], N=7; participants with mild AD, N=3) underwent neuropsychological testing, MRI (T1-weighted and T1rho [spin-lattice relaxation time in the rotating frame]), and positron emission tomography imaging ([11C]Pittsburg compound B for amyloid burden [N=26] and [18F]fluorodeoxyglucose for cerebral glucose metabolism [N=12]). The relationships between global T1rho values and neuropsychological, demographic, and imaging measures were explored. RESULTS Global mean and median T1rho were positively associated with age. After controlling for age, higher global T1rho was associated with poorer cognitive function, poorer memory function (immediate and delayed memory scores), higher amyloid burden, and more abnormal cerebral glucose metabolism. Regional T1rho values, when controlling for age, significantly differed between HCs and participants with MCI or AD in select frontal, cingulate, and parietal regions. CONCLUSIONS Higher T1rho values were associated with greater cognitive impairment and pathological burden. T1rho, a biomarker that varies according to a feature common to each cascade rather than one that is unique to a particular pathology, has the potential to serve as a metric of neuropathology, theoretically providing a measure for assessing pathological status and for monitoring the neurodegeneration trajectory.
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Affiliation(s)
| | - Vincent A. Magnotta
- Department of Radiology, Carver College of Medicine, University of Iowa,Department of Psychiatry, Carver College of Medicine, University of Iowa
| | - Yusuf Menda
- Department of Radiology, Carver College of Medicine, University of Iowa
| | - David J. Moser
- Department of Psychiatry, Carver College of Medicine, University of Iowa
| | - Jacob J. Oleson
- Department of Biostatistics, College of Public Health, University of Iowa
| | - Emily L. Harlynn
- Department of Radiology, Carver College of Medicine, University of Iowa
| | - Sean D. DeVries
- Department of Biostatistics, College of Public Health, University of Iowa
| | - John A. Wemmie
- Department of Psychiatry, Carver College of Medicine, University of Iowa
| | - Susan K. Schultz
- Department of Psychiatry, Carver College of Medicine, University of Iowa
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23
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Shaffer JJ, Mani M, Schmitz SL, Xu J, Owusu N, Wu D, Magnotta VA, Wemmie JA. Proton Exchange Magnetic Resonance Imaging: Current and Future Applications in Psychiatric Research. Front Psychiatry 2020; 11:532606. [PMID: 33192650 PMCID: PMC7542226 DOI: 10.3389/fpsyt.2020.532606] [Citation(s) in RCA: 4] [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: 02/04/2020] [Accepted: 09/02/2020] [Indexed: 12/20/2022] Open
Abstract
Proton exchange provides a powerful contrast mechanism for magnetic resonance imaging (MRI). MRI techniques sensitive to proton exchange provide new opportunities to map, with high spatial and temporal resolution, compounds important for brain metabolism and function. Two such techniques, chemical exchange saturation transfer (CEST) and T1 relaxation in the rotating frame (T1ρ), are emerging as promising tools in the study of neurological and psychiatric illnesses to study brain metabolism. This review describes proton exchange for non-experts, highlights the current status of proton-exchange MRI, and presents advantages and drawbacks of these techniques compared to more traditional methods of imaging brain metabolism, including positron emission tomography (PET) and MR spectroscopy (MRS). Finally, this review highlights new frontiers for the use of CEST and T1ρ in brain research.
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Affiliation(s)
- Joseph J Shaffer
- Department of Radiology, University of Iowa, Iowa City, IA, United States
| | - Merry Mani
- Department of Radiology, University of Iowa, Iowa City, IA, United States
| | - Samantha L Schmitz
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States
| | - Jia Xu
- Department of Radiology, University of Iowa, Iowa City, IA, United States
| | - Nana Owusu
- Department of Radiology, University of Iowa, Iowa City, IA, United States.,Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA, United States.,Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States
| | - Dee Wu
- Department of Radiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Vincent A Magnotta
- Department of Radiology, University of Iowa, Iowa City, IA, United States.,Department of Psychiatry, University of Iowa, Iowa City, IA, United States.,Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States
| | - John A Wemmie
- Department of Psychiatry, University of Iowa, Iowa City, IA, United States.,Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA, United States.,Department of Veterans Affairs Medical Center, Iowa City, IA, United States.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, United States.,Department of Neurosurgery, University of Iowa, Iowa City, IA, United States
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24
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Zhu Y, Liu Y, Ying L, Liu X, Zheng H, Liang D. Bio-SCOPE: fast biexponential T 1ρ mapping of the brain using signal-compensated low-rank plus sparse matrix decomposition. Magn Reson Med 2019; 83:2092-2106. [PMID: 31762102 DOI: 10.1002/mrm.28067] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 09/28/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022]
Abstract
PURPOSE To develop and evaluate a fast imaging method based on signal-compensated low-rank plus sparse matrix decomposition to accelerate data acquisition for biexponential brain T1ρ mapping (Bio-SCOPE). METHODS Two novel strategies were proposed to improve reconstruction performance. A variable-rate undersampling scheme was used with a varied acceleration factor for each k-space along the spin-lock time direction, and a modified nonlinear thresholding scheme combined with a feature descriptor was used for Bio-SCOPE reconstruction. In vivo brain T1ρ mappings were acquired from 4 volunteers. The fully sampled k-space data acquired from 3 volunteers were retrospectively undersampled by net acceleration rates (R) of 4.6 and 6.1. Reference values were obtained from the fully sampled data. The agreement between the accelerated T1ρ measurements and reference values was assessed with Bland-Altman analyses. Prospectively undersampled data with R = 4.6 and R = 6.1 were acquired from 1 volunteer. RESULTS T1ρ -weighted images were successfully reconstructed using Bio-SCOPE for R = 4.6 and 6.1 with signal-to-noise ratio variations <1 dB and normalized root mean square errors <4%. Accelerated and reference T1ρ measurements were in good agreement for R = 4.6 (T1ρ s : 18.6651 ± 1.7786 ms; T1ρ l : 88.9603 ± 1.7331 ms) and R = 6.1 (T1ρ s : 17.8403 ± 3.3302 ms; T1ρ l : 88.0275 ± 4.9606 ms) in the Bland-Altman analyses. T1ρ parameter maps from prospectively undersampled data also show reasonable image quality using the Bio-SCOPE method. CONCLUSION Bio-SCOPE achieves a high net acceleration rate for biexponential T1ρ mapping and improves reconstruction quality by using a variable-rate undersampling data acquisition scheme and a modified soft-thresholding algorithm in image reconstruction.
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Affiliation(s)
- Yanjie Zhu
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Yuanyuan Liu
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,University of Chinese Academy of Sciences, Beijing, China.,Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China
| | - Leslie Ying
- Department of Biomedical Engineering and Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, New York
| | - Xin Liu
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Dong Liang
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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25
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Bouhrara M, Rejimon AC, Cortina LE, Khattar N, Spencer RG. Four-angle method for practical ultra-high-resolution magnetic resonance mapping of brain longitudinal relaxation time and apparent proton density. Magn Reson Imaging 2019; 66:57-68. [PMID: 31730882 DOI: 10.1016/j.mri.2019.11.013] [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: 08/23/2019] [Revised: 11/09/2019] [Accepted: 11/10/2019] [Indexed: 10/25/2022]
Abstract
Changes in longitudinal relaxation time (T1) and proton density (PD) are sensitive indicators of microstructural alterations associated with various central nervous system diseases as well as brain maturation and aging. In this work, we introduce a new approach for rapid and accurate high-resolution (HR) or ultra HR (UHR) mapping of T1 and apparent PD (APD) of the brain with correction of radiofrequency field, B1, inhomogeneities. The four-angle method (FAM) uses four spoiled-gradient recalled-echo (SPGR) images acquired at different flip angles (FA) and short repetition times (TRs). The first two SPGR images are acquired at low-spatial resolution and used to accurately map the active B1+ field with the recently introduced steady-state double angle method (SS-DAM). The estimated B1+ map is used in conjunction with the two other SPGR images, acquired at HR or UHR, to map T1 and APD. The method is evaluated with numerical, phantom, and in-vivo imaging measurements. Furthermore, we investigated imaging acceleration methods to further shorten the acquisition time. Our results indicate that FAM provides an accurate method for simultaneous HR or UHR mapping of T1 and APD in human brain in clinical high-field MRI. Derived parameter maps without B1+correction suffer from large inaccuracies, but this issue is well-corrected through use of the SS-DAM. Furthermore, the use of SPGR imaging with short TR and phased-array coil acquisition permits substantial imaging acceleration and enables robust HR or UHR T1 and APD mapping in a clinically acceptable time frame, with whole brain coverage obtained in less than 2 min or 5 min, respectively. The method exhibits high reproducibility and benefits from the use of the conventional SPGR sequence, available in all preclinical and clinical MRI machines, and very simple modeling to address a critical outstanding issue in neuroimaging.
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Affiliation(s)
- Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
| | - Abinand C Rejimon
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Luis E Cortina
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Nikkita Khattar
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Richard G Spencer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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26
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Hu P, Sun J, Lv F, Pi B, Xu F, Han G, Hu X, Wang Y, Huang N, Wu X, Yang X. Diffusion-weighted imaging and variable flip angle T1 mapping: a supplement for image-guided biopsy in follow-up analysis of liver fibrosis. J Interv Med 2019; 1:150-156. [PMID: 34805843 PMCID: PMC8586563 DOI: 10.19779/j.cnki.2096-3602.2018.03.04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Purpose To evaluate the performance of diffusion-weighted imaging (DWI) and variable flip angle (VFA) T1 mapping as a supplement to image-guided biopsy in follow-up analysis of liver fibrosis. Materials and Methods This prospective study was approved by the institution's committee on human research, and written informed consent was provided from the enrolled patients. We investigated five MRI parameters of DWI and VFA T1 mapping, collected from 11 patients who underwent serial ultrasound image-guided biopsy with follow-up MRI within 1.5 years after treatment for liver fibrosis/cirrhosis. For each patient, four consecutive MRI examinations were conducted, including baseline MRI before treatment and three follow-up MRI examinations after treatment at each 0.5-year interval. ADC values at four b values and T1 relaxation times were correlated to pathology-confirmed liver fibrosis stages, which were subsequently divided into two groups, stages F2-3 and F4. The receiver operating characteristic (ROC) analysis and repeated measurement analysis of variance were used for statistical analysis. Results Among these ADC parameters, ADC value (b = 500 s/mm2) was the most consistent in differentiating between stage F2-3 and F4 liver fibrosis. Repeated measurement analysis showed that the intra-group and inter-group differences were 0.447 and 0.024, respectively. T1 relaxation time could not consistently differentiate between the F2-3 and F4 groups; however, it was repeatable, and the intra-group and inter-group differences were 0.410 and 0.042, respectively. Conclusion MRI-ADC value at a b value of 500 s/mm2 can be a promising biomarker for differentiating stages F2-3 and F4 liver fibrosis. A combination of this biomarker with repeatable T1 relaxation time may function as a non-invasive tool for follow-up liver fibrosis in patients who reject repeated image-guided biopsy.
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Affiliation(s)
- Peng Hu
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Jihong Sun
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China,Correspondence: Xiaoming Yang, MD, PhD, Image-Guided Bio-Molecular Interventions Research, Department of Radiology, University of Washington School of Medicine, 815 Mercer Street, Room S470, Seattle, WA 98109, USA, Tel: +1-206-685-6967; E-mail: . Jihong Sun MD, PhD, Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, Zhejiang 310016, China, Tel: +86-571-86006764; E-mail:
| | - Fangfang Lv
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Borui Pi
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Fangping Xu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Guocan Han
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Xi Hu
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Yue Wang
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | | | - Xia Wu
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China
| | - Xiaoming Yang
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou City 310016, Zhejiang Province, China,Image-Guided Bio-Molecular Interventions Research, Department of Radiology, University of Washington School of Medicine, Seattle, WA, USA 98109,Correspondence: Xiaoming Yang, MD, PhD, Image-Guided Bio-Molecular Interventions Research, Department of Radiology, University of Washington School of Medicine, 815 Mercer Street, Room S470, Seattle, WA 98109, USA, Tel: +1-206-685-6967; E-mail: . Jihong Sun MD, PhD, Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, Zhejiang 310016, China, Tel: +86-571-86006764; E-mail:
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Brain T1ρ mapping for grading and IDH1 gene mutation detection of gliomas: a preliminary study. J Neurooncol 2018; 141:245-252. [PMID: 30414094 DOI: 10.1007/s11060-018-03033-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/15/2018] [Indexed: 01/08/2023]
Abstract
INTRODUCTION The longitudinal relaxation time in the rotating frame (T1ρ) has proved to be sensitive to metabolism and useful in application to neurodegenerative diseases. However, few literature exists on its utility in gliomas. Thus, this study was conducted to explore the performance of T1ρ mapping in tumor grading and characterization of isocitrate dehydrogenase 1 (IDH1) gene mutation status of gliomas. METHODS Fifty-seven patients with gliomas underwent brain MRI and quantitative measurements of T1ρ and apparent diffusion coefficient (ADC) were recorded. Parameters were compared between high-grade gliomas (HGG) and low-grade gliomas (LGG) and between IDH1 mutant and wildtype groups. RESULTS HGG showed significantly higher T1ρ values in both the solid and peritumoral edema areas compared with LGG (P < 0.001 and P = 0.005, respectively), whereas no significant differences in the two areas were found for ADC (both P > 0.05). Receiver operating characteristic (ROC) curve analysis showed that T1ρ value in the solid area achieved the highest area under the ROC curve (AUC, 0.841) in grading with a sensitivity of 80.6% and a specificity of 81.0%. In the grade II/III glioma group, multivariate logistic regression showed that both tumor frontal lobe location (odds ratio [OR] 526.608; P = 0.045) and T1ρ value of the peritumoral edema area (OR 0.863; P = 0.037) were significant predictors of IDH1 mutation. Using the combination, the diagnostic sensitivity and specificity for IDH1 mutated gliomas were 93.3% and 88.9%, respectively. CONCLUSIONS Our study shows the feasibility of applying T1ρ mapping in assessing the histologic grade and IDH1 mutation status of gliomas.
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Zhu Y, Liu Y, Ying L, Peng X, Wang YXJ, Yuan J, Liu X, Liang D. SCOPE: signal compensation for low-rank plus sparse matrix decomposition for fast parameter mapping. Phys Med Biol 2018; 63:185009. [PMID: 30117434 DOI: 10.1088/1361-6560/aadb09] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Magnetic resonance (MR) parameter mapping is useful for many clinical applications. However, its practical utility is limited by the long scan time. To address this problem, this paper developed a novel image reconstruction method for fast MR parameter mapping. The proposed method (SCOPE) used a low-rank plus sparse model to reconstruct the parameter-weighted images from highly undersampled acquisitions. A signal compensation strategy was introduced to promote low rankness along the parametric direction and thus improve the reconstruction accuracy. Specifically, compensation was performed by multiplying the original signal by the inversion of the mono-exponential decay at each voxel. The performance of SCOPE was evaluated via quantitative T 1ρ mapping. The results of the simulation and in vivo experiments with acceleration factors from 3 to 5 are shown. The performance of SCOPE was verified via comparisons with several low-rank and sparsity-based methods. The experimental results showed that the T 1ρ maps obtained using SCOPE were more accurate than those obtained using competing methods and were comparable to the reference, even when the acceleration factor reached 5. SCOPE can greatly reduce the scan time of parameter mapping while still achieving high accuracy. This technique might therefore help facilitate fast MR parameter mapping in clinical use.
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Affiliation(s)
- Yanjie Zhu
- Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, People's Republic of China. Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States of America. These authors contributed equally to this work
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Jiang B, Chen W. On-resonance and off-resonance continuous wave constant amplitude spin-lock and T 1ρ quantification in the presence of B 1 and B 0 inhomogeneities. NMR IN BIOMEDICINE 2018; 31:e3928. [PMID: 29693744 DOI: 10.1002/nbm.3928] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 02/06/2018] [Accepted: 03/06/2018] [Indexed: 06/08/2023]
Abstract
Spin-lock MRI is a valuable diagnostic imaging technology, as it can be used to probe the macromolecule environment of tissues. Quantitative T1ρ imaging is one application of spin-lock MRI that is reported to be promising for a number of clinical applications. Spin-lock is often performed with a continuous RF wave at a constant RF amplitude either on resonance or off resonance. However, both on- and off-resonance spin-lock approaches are susceptible to B1 and B0 inhomogeneities, which results in image artifacts and quantification errors. In this work, we report a continuous wave constant amplitude spin-lock approach that can achieve negligible image artifacts in the presence of B1 and B0 inhomogeneities for both on- and off-resonance spin-lock. Under the adiabatic condition, by setting the maximum B1 amplitude of the adiabatic pulses equal to the B1 amplitude of spin-lock RF pulse, the spins are ensured to align along the effective field throughout the spin-lock process. We show that this results in simultaneous compensation of B1 and B0 inhomogeneities for both on- and off-resonance spin-lock. The relaxation effect during the entire adiabatic half passage (AHP) and reverse AHP, and the stationary solution of the Bloch-McConnell equation present at off-resonance frequency offset, are considered in the revised relaxation model. We demonstrate that these factors create a direct current component to the conventional relaxation model. In contrast to the previously reported dual-acquisition method, the revised relaxation model just requires one acquisition to perform quantification. The simulation, phantom, and in vivo experiments demonstrate that the proposed approach achieves superior image quality compared with the existing methods, and the revised relaxation model can perform T1ρ quantification with one acquisition instead of two.
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Affiliation(s)
- Baiyan Jiang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China
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Bouhrara M, Reiter DA, Bergeron CM, Zukley LM, Ferrucci L, Resnick SM, Spencer RG. Evidence of demyelination in mild cognitive impairment and dementia using a direct and specific magnetic resonance imaging measure of myelin content. Alzheimers Dement 2018; 14:998-1004. [PMID: 29679574 DOI: 10.1016/j.jalz.2018.03.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 02/22/2018] [Accepted: 03/01/2018] [Indexed: 12/30/2022]
Abstract
INTRODUCTION We investigated brain demyelination in aging, mild cognitive impairment (MCI), and dementia using a direct magnetic resonance imaging marker of myelin. METHODS Brains of young and old controls, and old subjects with MCI, Alzheimer's disease, or vascular dementia were scanned using our recently developed myelin water fraction (MWF) mapping technique, which provides greatly improved accuracy over previous comparable methods. Maps of MWF, a direct and specific myelin measure, and relaxation times and magnetization transfer ratio, indirect and nonspecific measures, were constructed. RESULTS MCI subjects showed decreased MWF compared with old controls. Demyelination was greater in Alzheimer's disease or vascular dementia. As expected, decreased MWF was accompanied by decreased magnetization transfer ratio and increased relaxation times. The young subjects showed greater myelin content than the old subjects. DISCUSSION We believe this to be the first demonstration of myelin loss in MCI, Alzheimer's disease, and vascular dementia using a method that provides a quantitative magnetic resonance imaging-based measure of myelin. Our findings add to the emerging evidence that myelination may represent an important biomarker for the pathology of MCI and dementia. This study supports the investigation of the role of myelination in MCI and dementia through use of this quantitative magnetic resonance imaging approach in clinical studies of disease progression, and relationship of functional status to myelination status. Furthermore, mapping MWF may permit myelin to serve as a therapeutic target in clinical trials.
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Affiliation(s)
- Mustapha Bouhrara
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
| | - David A Reiter
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Christopher M Bergeron
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Linda M Zukley
- Clinical Research Core, Office of the Scientific Director, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Luigi Ferrucci
- Translational Gerontology Branch, National Institutes of Health, Baltimore, MD, USA
| | - Susan M Resnick
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Richard G Spencer
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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Li YT, Huang H, Zhuo Z, Lu PX, Chen W, Wáng YXJ. Bi-phase age-related brain gray matter magnetic resonance T1ρ relaxation time change in adults. Magn Reson Imaging 2017; 39:200-205. [DOI: 10.1016/j.mri.2017.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 02/02/2017] [Accepted: 03/15/2017] [Indexed: 12/18/2022]
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Dong H, Hwang SM, Wendland M, You L, Clarke J, Inglis B. Ultralow-field and spin-locking relaxation dispersion in postmortem pig brain. Magn Reson Med 2017; 78:2342-2351. [PMID: 28164366 DOI: 10.1002/mrm.26621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 11/28/2016] [Accepted: 01/02/2017] [Indexed: 11/08/2022]
Abstract
PURPOSE To investigate tissue-specific differences, a quantitative comparison was made between relaxation dispersion in postmortem pig brain measured at ultralow fields (ULF) and spin locking at 7 tesla (T). The goal was to determine whether ULF-MRI has potential advantages for in vivo human brain imaging. METHODS Separate specimens of gray matter and white matter were investigated using an ULF-MRI system with superconducting quantum interference device (SQUID) signal detection to measure T1ULF at fields from 58.7 to 235.0 μT and using a commercial MRI scanner to measure T1ρ7T at spin-locking fields from 5.0 to 235.0 μT. RESULTS At matched field strengths, T1ρ7T is 50 to 100% longer than T1ULF. Furthermore, dispersion in T1ULF is close to linear between 58.7 and 235 µT, whereas dispersion in T1ρ7T is highly nonlinear over the same range. A subtle elbow in the T1ULF dispersion at approximately 140 µT is tentatively attributed to the local dipolar field of macromolecules. It is suggested that different relaxation mechanisms dominate each method and that ULF-MRI has a fundamentally different sensitivity to the macromolecular structure of neural tissue. CONCLUSIONS Ultralow-field MRI may offer distinct, quantitative advantages for human brain imaging, while simultaneously avoiding the severe heating limitation imposed on high-field spin locking. Magn Reson Med 78:2342-2351, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Hui Dong
- Department of Physics, University of California, Berkeley, California, USA.,State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences (CAS), Shanghai, China.,CAS Center for ExcelleNce in Superconducting Electronics (CENSE), Shanghai, China
| | - Seong-Min Hwang
- Department of Physics, University of California, Berkeley, California, USA.,Center for Biosignals, Korea Research Institute of Standards and Science, Daejeon, Republic of Korea
| | - Michael Wendland
- Berkeley Preclinical Imaging Core (BPIC) Facility, University of California, Berkeley, California, USA
| | - Lixing You
- Department of Physics, University of California, Berkeley, California, USA.,State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences (CAS), Shanghai, China.,CAS Center for ExcelleNce in Superconducting Electronics (CENSE), Shanghai, China
| | - John Clarke
- Department of Physics, University of California, Berkeley, California, USA
| | - Ben Inglis
- Henry H. Wheeler, Jr. Brain Imaging Center (BIC), University of California, Berkeley, California, USA
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Chen W. Artifacts correction for T1rho imaging with constant amplitude spin-lock. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 274:13-23. [PMID: 27842257 DOI: 10.1016/j.jmr.2016.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 10/16/2016] [Accepted: 11/04/2016] [Indexed: 06/06/2023]
Abstract
T1rho imaging with constant amplitude spin-lock is prone to artifacts in the presence of B1 RF and B0 field inhomogeneity. Despite significant technological progress, improvements on the robustness of constant amplitude spin-lock are necessary in order to use it for routine clinical practice. This work proposes methods to simultaneously correct for B1 RF and B0 field inhomogeneity in constant amplitude spin-lock. By setting the maximum B1 amplitude of the excitation adiabatic pulses equal to the expected constant amplitude spin-lock frequency, the spins become aligned along the effective field throughout the spin-lock process. This results in T1rho-weighted images free of artifacts, despite the spatial variation of the effective field caused by B1 RF and B0 field inhomogeneity. When the pulse is long, the relaxation effect during the adiabatic half passage may result in a non-negligible error in the mono-exponential relaxation model. A two-acquisition approach is presented to solve this issue. Simulation, phantom, and in-vivo scans demonstrate the proposed methods achieve superior image quality compared to existing methods, and that the two-acquisition method is effective in resolving the relaxation effect during the adiabatic half passage.
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Affiliation(s)
- Weitian Chen
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong Special Administrative Region.
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Chu C, Zhou N, Zhang H, Dou X, Li M, Liu S, Zhu Y, Chen W, Chan Q, He J, Sun L, Zhou Z. Use of T1ρMR imaging in Sjögren's syndrome with normal appearing parotid glands: Initial findings. J Magn Reson Imaging 2016; 45:1005-1012. [PMID: 27726238 DOI: 10.1002/jmri.25494] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/11/2016] [Accepted: 09/12/2016] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To explore the feasibility of parotid spin-lattice relaxation time in the rotating frame (T1ρ) MR imaging in the diagnosis of Sjögren's syndrome (SS) without morphological changes of the parotid glands. MATERIALS AND METHODS The study enrolled 32 consecutive SS patients without morphological changes of parotid glands and 32 age- and gender-matched healthy volunteers who underwent parotid 3.0 Tesla MR imaging, including T1ρ sequences. Follow-up imaging was performed at 3 months. T1 signal intensities and T1ρ values of bilateral parotid glands were compared using paired samples t-test. Parotid T1 signal intensities and T1ρ values were compared using two independent samples t-test. Diagnostic performance of the parotid T1ρ values was evaluated by receiver operating characteristic analysis. The intraclass correlation coefficient (ICC) was calculated to evaluate the reproducibility of parotid T1ρ measurements. RESULTS There were no significant differences of T1 signal intensities and T1ρ values between bilateral parotid glands in SS patients and healthy volunteers (P = 0.170, 0.886 and 0.942, 0.229). The parotid T1ρ values of SS patients (96.47 ± 15.38 ms) were significantly higher than those of healthy volunteers (84.25 ± 6.11 ms) (P < 0.001), while there were no significant differences of T1 signal intensities between SS patients and healthy volunteers (P = 0.655). With a cutoff value of 88.02 ms, the sensitivity and specificity of the parotid T1ρ value was 75.0% and 100.0% in the diagnosis of SS. The reproducibility of parotid T1ρ measurement was excellent (ICC: 0.934-0.995). CONCLUSION Parotid T1ρ MR imaging held a potential role in diagnosing SS without morphological changes of parotid glands. LEVEL OF EVIDENCE 2 J. Magn. Reson. Imaging 2017;45:1005-1012.
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Affiliation(s)
- Chen Chu
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Nan Zhou
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Huayong Zhang
- Department of Rheumatology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Xin Dou
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Ming Li
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Song Liu
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Yun Zhu
- Department of Rheumatology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | | | | | - Jian He
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Lingyun Sun
- Department of Rheumatology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Zhengyang Zhou
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
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35
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Spear JT, Gore JC. New insights into rotating frame relaxation at high field. NMR IN BIOMEDICINE 2016; 29:1258-73. [PMID: 26866422 PMCID: PMC6935321 DOI: 10.1002/nbm.3490] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/07/2015] [Accepted: 12/30/2015] [Indexed: 05/03/2023]
Abstract
Measurements of spin-lock relaxation rates in the rotating frame (R1ρ ) at high magnetic fields afford the ability to probe not only relatively slow molecular motions, but also other dynamic processes, such as chemical exchange and diffusion. In particular, measurements of the variation (or dispersion) of R1ρ with locking field allow the derivation of quantitative parameters that describe these processes. Measurements in deuterated solutions demonstrate the manner and degree to which exchange dominates relaxation at high fields (4.7 T, 7 T) in simple solutions, whereas temperature and pH are shown to be very influential factors affecting the rates of proton exchange. Simulations and experiments show that multiple exchanging pools of protons in realistic tissues can be assumed to behave independently of each other. R1ρ measurements can be combined to derive an exchange rate contrast (ERC) that produces images whose intensities emphasize protons with specific exchange rates rather than chemical shifts. In addition, water diffusion in the presence of intrinsic susceptibility gradients may produce significant effects on R1ρ dispersions at high fields. The exchange and diffusion effects act independently of each other, as confirmed by simulation and experimentally in studies of red blood cells at different levels of oxygenation. Collectively, R1ρ measurements provide an ability to quantify exchange processes, to provide images that depict protons with specific exchange rates and to describe the microstructure of tissues containing magnetic inhomogeneities. As such, they complement traditional T1 or T2 measurements and provide additional insights from measurements of R1ρ at a single locking field. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- John T. Spear
- Correspondence to: J. T. Spear, Physics and Astronomy, Vanderbilt University Institute of Imaging Science, Nashville, TN 37232, USA.
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36
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Zhang H, Yang Q, Yu T, Chen X, Huang J, Tan C, Liang B, Guo H. Comparison of T2, T1rho, and diffusion metrics in assessment of liver fibrosis in rats. J Magn Reson Imaging 2016; 45:741-750. [PMID: 27527587 DOI: 10.1002/jmri.25424] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/02/2016] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To evaluate the value of T2 , T1 rho, and diffusion metrics in assessment of liver fibrosis in rats. MATERIALS AND METHODS Liver fibrosis in a rat model (n = 72) was induced by injection of carbon tetrachloride (CCl4 ) at 3T. T2 , T1 rho, and diffusion parameters (apparent diffusion coefficient (ADC), Dtrue ) via spin echo (SE) diffusion-weighted imaging (DWI) and stimulated echo acquisition mode (STEAM) DWI with three diffusion times (DT: 80, 106, 186 msec) were obtained in surviving rats with hepatic fibrosis (n = 52) and controls (n = 8). Liver fibrosis stage (F0-F6) was identified based on pathological results using the traditional liver fibrosis staging method for rodents. Nonparametric statistical methods and receiver operating characteristic (ROC) curve analysis were employed to determine the diagnostic accuracy. RESULTS Mean T2 , T1 rho, ADC, and Dtrue with DT = 186 msec correlated with the severity of fibrosis with r = 0.73, 0.83, -0.83, and -0.85 (all P < 0.001), respectively. The average areas under the ROC curve at different stages for T1 rho and diffusion parameters (DT = 186 msec) were larger than those of T2 and SE DWI (0.92, 0.92, and 0.92 vs. 0.86, 0.82, and 0.83). The corresponding average sensitivity and specificity for T1 rho and diffusion parameters with a long DT were larger (89.35 and 88.90, 88.36 and 89.97, 90.16 and 87.13) than T2 and SE DWI (90.28 and 79.93, 85.30 and 77.64, 78.21 and 82.41). The performances of T1 rho and Dtrue (DT = 186 msec) were comparable (average AUC: 0.92 and 0.92). CONCLUSION Among the evaluated sequences, T1 rho and STEAM DWI with a long DT may serve as superior imaging biomarkers for assessing liver fibrosis and monitoring disease severity. LEVEL OF EVIDENCE 1 J. Magn. Reson. Imaging 2017;45:741-750.
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Affiliation(s)
- Hui Zhang
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, Beijing, China
| | - Qihua Yang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Taihui Yu
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xiaodong Chen
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, Beijing, China.,Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.,Department of Radiology, Affiliated hospital of Guangdong Medical College, Guangdong, China
| | - Jingwen Huang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Cui Tan
- Department of Pathology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Biling Liang
- Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Hua Guo
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, Beijing, China
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Schuenke P, Koehler C, Korzowski A, Windschuh J, Bachert P, Ladd ME, Mundiyanapurath S, Paech D, Bickelhaupt S, Bonekamp D, Schlemmer HP, Radbruch A, Zaiss M. Adiabatically prepared spin-lock approach for T1ρ-based dynamic glucose enhanced MRI at ultrahigh fields. Magn Reson Med 2016; 78:215-225. [DOI: 10.1002/mrm.26370] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/12/2016] [Accepted: 07/14/2016] [Indexed: 12/23/2022]
Affiliation(s)
- Patrick Schuenke
- German Cancer Research Center (DKFZ); Division of Medical Physics in Radiology; Heidelberg Germany
| | - Christina Koehler
- German Cancer Research Center (DKFZ); Division of Radiology; Heidelberg Germany
| | - Andreas Korzowski
- German Cancer Research Center (DKFZ); Division of Medical Physics in Radiology; Heidelberg Germany
| | - Johannes Windschuh
- German Cancer Research Center (DKFZ); Division of Medical Physics in Radiology; Heidelberg Germany
| | - Peter Bachert
- German Cancer Research Center (DKFZ); Division of Medical Physics in Radiology; Heidelberg Germany
| | - Mark E. Ladd
- German Cancer Research Center (DKFZ); Division of Medical Physics in Radiology; Heidelberg Germany
| | | | - Daniel Paech
- German Cancer Research Center (DKFZ); Division of Radiology; Heidelberg Germany
| | | | - David Bonekamp
- German Cancer Research Center (DKFZ); Division of Radiology; Heidelberg Germany
| | | | - Alexander Radbruch
- German Cancer Research Center (DKFZ); Division of Radiology; Heidelberg Germany
| | - Moritz Zaiss
- German Cancer Research Center (DKFZ); Division of Medical Physics in Radiology; Heidelberg Germany
- Max-Planck-Institute for Biological Cybernetics; Tübingen Baden-Württemberg Germany
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38
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Gilani IA, Sepponen R. Quantitative rotating frame relaxometry methods in MRI. NMR IN BIOMEDICINE 2016; 29:841-861. [PMID: 27100142 DOI: 10.1002/nbm.3518] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 01/21/2016] [Accepted: 02/18/2016] [Indexed: 06/05/2023]
Abstract
Macromolecular degeneration and biochemical changes in tissue can be quantified using rotating frame relaxometry in MRI. It has been shown in several studies that the rotating frame longitudinal relaxation rate constant (R1ρ ) and the rotating frame transverse relaxation rate constant (R2ρ ) are sensitive biomarkers of phenomena at the cellular level. In this comprehensive review, existing MRI methods for probing the biophysical mechanisms that affect the rotating frame relaxation rates of the tissue (i.e. R1ρ and R2ρ ) are presented. Long acquisition times and high radiofrequency (RF) energy deposition into tissue during the process of spin-locking in rotating frame relaxometry are the major barriers to the establishment of these relaxation contrasts at high magnetic fields. Therefore, clinical applications of R1ρ and R2ρ MRI using on- or off-resonance RF excitation methods remain challenging. Accordingly, this review describes the theoretical and experimental approaches to the design of hard RF pulse cluster- and adiabatic RF pulse-based excitation schemes for accurate and precise measurements of R1ρ and R2ρ . The merits and drawbacks of different MRI acquisition strategies for quantitative relaxation rate measurement in the rotating frame regime are reviewed. In addition, this review summarizes current clinical applications of rotating frame MRI sequences. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Irtiza Ali Gilani
- Brain Research Unit, Department of Neuroscience and Biomedical Engineering, Aalto University, Aalto, Finland
- Advanced Magnetic Imaging Center, Aalto University, Aalto, Finland
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Raimo Sepponen
- Department of Electronics, School of Electrical Engineering, Aalto University, Aalto, Finland
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Yang Q, Yu T, Yun S, Zhang H, Chen X, Cheng Z, Zhong J, Huang J, Okuaki T, Chan Q, Liang B, Guo H. Comparison of multislice breath-hold and 3D respiratory triggeredT1ρ imaging of liver in healthy volunteers and liver cirrhosis patients in 3.0 T MRI. J Magn Reson Imaging 2016; 44:906-13. [PMID: 27149283 DOI: 10.1002/jmri.25253] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 03/06/2016] [Indexed: 01/09/2023] Open
Affiliation(s)
- Qihua Yang
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Taihui Yu
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Su Yun
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Hui Zhang
- Center for Biomedical Imaging Research; Department of Biomedical Engineering; Tsinghua University; Beijing China
| | - Xiaodong Chen
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Ziliang Cheng
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Jinglian Zhong
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Jingwen Huang
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | | | | | - Biling Liang
- Sun Yat-Sen Memorial Hospital; Guang Zhou Guang Dong China
| | - Hua Guo
- Center for Biomedical Imaging Research; Department of Biomedical Engineering; Tsinghua University; Beijing China
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40
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Wáng YXJ, Zhang Q, Li X, Chen W, Ahuja A, Yuan J. T1ρ magnetic resonance: basic physics principles and applications in knee and intervertebral disc imaging. Quant Imaging Med Surg 2015; 5:858-85. [PMID: 26807369 PMCID: PMC4700236 DOI: 10.3978/j.issn.2223-4292.2015.12.06] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 12/06/2015] [Indexed: 12/15/2022]
Abstract
T1ρ relaxation time provides a new contrast mechanism that differs from T1- and T2-weighted contrast, and is useful to study low-frequency motional processes and chemical exchange in biological tissues. T1ρ imaging can be performed in the forms of T1ρ-weighted image, T1ρ mapping and T1ρ dispersion. T1ρ imaging, particularly at low spin-lock frequency, is sensitive to B0 and B1 inhomogeneity. Various composite spin-lock pulses have been proposed to alleviate the influence of field inhomogeneity so as to reduce the banding-like spin-lock artifacts. T1ρ imaging could be specific absorption rate (SAR) intensive and time consuming. Efforts to address these issues and speed-up data acquisition are being explored to facilitate wider clinical applications. This paper reviews the T1ρ imaging's basic physic principles, as well as its application for cartilage imaging and intervertebral disc imaging. Compared to more established T2 relaxation time, it has been shown that T1ρ provides more sensitive detection of proteoglycan (PG) loss at early stages of cartilage degeneration. T1ρ has also been shown to provide more sensitive evaluation of annulus fibrosis (AF) degeneration of the discs.
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Zhao F, Yuan J, Lu G, Zhang LH, Chen ZY, Wáng YXJ. T1ρ relaxation time in brain regions increases with ageing: an experimental MRI observation in rats. Br J Radiol 2015; 89:20140704. [PMID: 26529226 DOI: 10.1259/bjr.20140704] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE T1ρ variation is associated with neurodegenerative diseases. This study aims to observe T1ρ relaxation time changes in rat brains associated with normal ageing in Sprague-Dawley (SD) rats, Wistar Kyoto (WKY) rats and spontaneously hypertension rats (SHRs). METHODS 18 male SD rats, 11 male WKY rats and 11 male SHRs were used. T1ρ measurement was performed at 3-T MR with a spin-lock frequency of 500 Hz. SD rats were scanned at the ages of 5, 8, 10 and 15 months. SHRs and WKY rats were scanned at the ages of 6, 9 and 12 months. RESULTS For SD rats, T1ρ at the thalamus, hippocampus and frontal cortices increased significantly from 5 to 15 months (p < 0.05). For the WKY rats and SHRs, the T1ρ values in the thalamus, hippocampus and frontal cortices also increased significantly from 6 to 12 months (p < 0.05). Furthermore, T1ρ in the thalamus, hippocampus and frontal cortices of SHRs were consistently higher than those of WKY rats at the ages of 6, 9 and 12 months (p < 0.05). The percentage regional T1ρ differences between WKY rats and SHRs did not change during ageing. CONCLUSION An increase in T1ρ was associated with age-related changes of the rat brain. ADVANCES IN KNOWLEDGE An age-related and hypertension-related T1ρ increase in rat brain regions was observed in the thalamus, hippocampus and frontal cortical regions of the rat brain.
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Affiliation(s)
- Feng Zhao
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
| | - Jing Yuan
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.,2 Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong
| | - Gang Lu
- 3 Division of Neurosurgery, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
| | - Li H Zhang
- 4 School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Zhi Y Chen
- 5 Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Yì-Xiáng J Wáng
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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Hu G, Zhang X, Liang W, Zhong X, Chan Q, Lin X, Lin T, Li Y, Quan X. Assessment of liver fibrosis in rats by MRI with apparent diffusion coefficient and T1 relaxation time in the rotating frame. J Magn Reson Imaging 2015; 43:1082-9. [PMID: 26497954 DOI: 10.1002/jmri.25084] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/14/2015] [Indexed: 12/19/2022] Open
Abstract
PURPOSE To explore the value of T1 relaxation times in the rotating frame (T1 ρ or T1 rho) for evaluating liver fibrosis stage, compared to apparent diffusion coefficients (ADCs). MATERIALS AND METHODS Liver fibrosis in model rats (n = 50) was produced by carbon tetrachloride (CCl4 ) injection. Five rats died during the experiment. Surviving model rats (n = 45) and controls (n = 15) were subjected to 3.0T MRI and the ADCs (b-values: 0, 800 s/mm(2) ) and T1 ρ values were determined. Liver fibrosis stage (F0-F4) was defined based on METAVIR scoring. Nonparametric statistical methods and receiver operating characteristic (ROC) curve analyses were employed to determine diagnostic accuracy. RESULTS Mean ADC and T1 ρ associated negatively (r = -0.732 P < 0.001) and positively (r = 0.863 P < 0.001), respectively, with severity of fibrosis stage. Analysis of ROC curves for fibrosis staging showed that the area under the curve (AUC) for T1 ρ (stage F0 vs. F1-F4 = 0.976, stage F0-F1 vs. F2-F4 = 0.920, stage F0-F2 vs. F3-F4 = 0.938, and stage F0-F3 vs. F4 = 0.931) was larger than that for ADCs (0.917, 0.924, 0.842, and 0.781, respectively). CONCLUSION ADC and T1 ρ values correlate with liver fibrosis stage. The performance of the T1 ρ parameter was superior to that of the ADC parameter in the differentiation of liver fibrosis stages in a CCl4 rat model.
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Affiliation(s)
- Genwen Hu
- Department of Medical Image Center, Shenzhen Bao'an Maternal and Child Health Hospital, Shenzhen, Guangdong Province, China.,Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xuhui Zhang
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Wen Liang
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xing Zhong
- Department of Medical Image Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong Province, China
| | | | - Xiaoying Lin
- Department of Medical Image Center, Shenzhen Bao'an Maternal and Child Health Hospital, Shenzhen, Guangdong Province, China
| | - Ting Lin
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yufa Li
- Department of Pathology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xianyue Quan
- Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
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Abstract
The spin-lattice relaxation time constant in rotating frame (T1rho) is useful for assessment of the properties of macromolecular environment inside tissue. Quantification of T1rho is found promising in various clinical applications. However, T1rho imaging is prone to image artifacts and quantification errors, which remains one of the greatest challenges to adopt this technique in routine clinical practice. The conventional continuous wave spin-lock is susceptible to B1 radiofrequency (RF) and B0 field inhomogeneity, which appears as banding artifacts in acquired images. A number of methods have been reported to modify T1rho prep RF pulse cluster to mitigate this effect. Adiabatic RF pulse can also be used for spin-lock with insensitivity to both B1 RF and B0 field inhomogeneity. Another source of quantification error in T1rho imaging is signal evolution during imaging data acquisition. Care is needed to affirm such error does not take place when specific pulse sequence is used for imaging data acquisition. Another source of T1rho quantification error is insufficient signal-to-noise ratio (SNR), which is common among various quantitative imaging approaches. Measurement of T1rho within an ROI can mitigate this issue, but at the cost of reduced resolution. Noise-corrected methods are reported to address this issue in pixel-wise quantification. For certain tissue type, T1rho quantification can be confounded by magic angle effect and the presence of multiple tissue components. Review of these confounding factors from inherent tissue properties is not included in this article.
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Affiliation(s)
- Weitian Chen
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, China
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44
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Singh A, Reddy D, Haris M, Cai K, Rajender Reddy K, Hariharan H, Reddy R. T1ρ MRI of healthy and fibrotic human livers at 1.5 T. J Transl Med 2015; 13:292. [PMID: 26350896 PMCID: PMC4562204 DOI: 10.1186/s12967-015-0648-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 08/21/2015] [Indexed: 01/06/2023] Open
Abstract
Background Liver fibrosis is a public health problem worldwide. There is a need of noninvasive imaging based methods for better diagnosis of this disease. In the current study, we aim to evaluate the potential of T1ρ MRI technique in detecting and characterizing different grades of liver fibrosis in vivo in humans. Methods Healthy subjects and patients with liver fibrosis were prospectively recruited for T1ρ MRI of liver on a 1.5 T MR scanner. Single slice T1ρ weighted images were acquired at different spin lock duration (0, 10, 20 and 30 ms) with spin lock amplitude of 500 Hz in a single breath-hold. Additionally, liver’s T1ρ images were acquired from five healthy subjects on the same day (n = 2) and different day (n = 2) sessions for test–retest study. Liver biopsy samples from patients were obtained and used to calculate the METAVIR score to define the stage of fibrosis and inflammation grade. T1ρ maps were generated followed by computation of mean and standard deviation (SD) values. Coefficient of variation (COV) of T1ρ values between two MRI scans was computed to determine reproducibility in liver. T test was used to compare T1ρ values between healthy and fibrotic liver. Pearson correlation was performed between stages of liver fibrosis and T1ρ values. Results The mean (SD) T1ρ value among subject with healthy liver was 51.04 (3.06) ms. The COV of T1ρ values between two repetitions in the same day session was 0.83 ± 0.8 % and in different day session was 5.4 ± 2.7 %. T1ρ values in fibrotic liver were significantly higher compared to those of healthy liver (p < 0.05). A statically significant correlation between stages of fibrosis and T1ρ values was observed (r = 0.99, p < 0.05). Inflammation score for one patient was 2 and for remaining patients it was 1. Conclusions Proposed T1ρ pulse sequence design and protocol enabled acquisition of a single slice T1ρ weighted images in a single breath-hold and hence mitigated breathing motion related artifacts. Preliminary results have shown the sensitivity of T1ρ values to changes induced by liver fibrosis, and may potentially be used as a clinical biomarker to delineate the stages of liver fibrosis. Further, studies on a large number of subjects are required to validate the observations of the current study. Nevertheless, T1ρ imaging can be easily setup on a clinical scanner to monitor the progression of liver fibrosis and to the evaluate efficacy of anti-fibrotic drugs.
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Affiliation(s)
- Anup Singh
- Department of Radiology, CMROI, University of Pennsylvania, Philadelphia, PA, USA. .,Center for Biomedical Engineering, Indian Institute of Technology Delhi, Block-II, Room No. 389, Hauz Khas, Delhi, 110016, India.
| | - Damodar Reddy
- Department of Radiology, CMROI, University of Pennsylvania, Philadelphia, PA, USA
| | - Mohammad Haris
- Department of Radiology, CMROI, University of Pennsylvania, Philadelphia, PA, USA.,Research Branch, Sidra Medical and Research Center, Doha, Qatar
| | - Kejia Cai
- Department of Radiology, CMROI, University of Pennsylvania, Philadelphia, PA, USA.,Department of Radiology, University of Illinois at Chicago, Chicago, IL, USA
| | - K Rajender Reddy
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hari Hariharan
- Department of Radiology, CMROI, University of Pennsylvania, Philadelphia, PA, USA
| | - Ravinder Reddy
- Department of Radiology, CMROI, University of Pennsylvania, Philadelphia, PA, USA
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45
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Granziera C, Daducci A, Donati A, Bonnier G, Romascano D, Roche A, Bach Cuadra M, Schmitter D, Klöppel S, Meuli R, von Gunten A, Krueger G. A multi-contrast MRI study of microstructural brain damage in patients with mild cognitive impairment. NEUROIMAGE-CLINICAL 2015; 8:631-9. [PMID: 26236628 PMCID: PMC4511616 DOI: 10.1016/j.nicl.2015.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 05/25/2015] [Accepted: 06/07/2015] [Indexed: 11/05/2022]
Abstract
Objectives The aim of this study was to investigate pathological mechanisms underlying brain tissue alterations in mild cognitive impairment (MCI) using multi-contrast 3 T magnetic resonance imaging (MRI). Methods Forty-two MCI patients and 77 healthy controls (HC) underwent T1/T2* relaxometry as well as Magnetization Transfer (MT) MRI. Between-groups comparisons in MRI metrics were performed using permutation-based tests. Using MRI data, a generalized linear model (GLM) was computed to predict clinical performance and a support-vector machine (SVM) classification was used to classify MCI and HC subjects. Results Multi-parametric MRI data showed microstructural brain alterations in MCI patients vs HC that might be interpreted as: (i) a broad loss of myelin/cellular proteins and tissue microstructure in the hippocampus (p ≤ 0.01) and global white matter (p < 0.05); and (ii) iron accumulation in the pallidus nucleus (p ≤ 0.05). MRI metrics accurately predicted memory and executive performances in patients (p ≤ 0.005). SVM classification reached an accuracy of 75% to separate MCI and HC, and performed best using both volumes and T1/T2*/MT metrics. Conclusion Multi-contrast MRI appears to be a promising approach to infer pathophysiological mechanisms leading to brain tissue alterations in MCI. Likewise, parametric MRI data provide powerful correlates of cognitive deficits and improve automatic disease classification based on morphometric features. Forty-two MCI patients and 77 HC underwent multi-contrast quantitative MRI. MCI patients showed T1/T2* increase and MTR decrease in the hippocampus. MCI patients exhibited T1 increase in WM and T2* decrease in the pallidus. MRI metrics accurately predicted memory and executive function in patients. SVM classified MCI patients with 75% accuracy using volumetric/parametric MRI.
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Affiliation(s)
- C Granziera
- Department of Clinical Neurosciences, CHUV, Lausanne, VD, Switzerland ; Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland
| | - A Daducci
- STI IEL LTS5, EPFL, Lausanne, VD, Switzerland
| | - A Donati
- Service of Old-Age Psychiatry, Department of Psychiatry, CHUV, Lausanne, VD, Switzerland
| | - G Bonnier
- Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland
| | - D Romascano
- Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland
| | - A Roche
- Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland
| | - M Bach Cuadra
- Department of Radiology, CHUV, Lausanne, VD, Switzerland ; Signal Processing Core, Center for Biomedical Imaging, CHUV, Lausanne, VD, Switzerland
| | - D Schmitter
- Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland
| | - S Klöppel
- Department of Psychiatry and Psychotherapy, Section of Gerontopsychiatry, Department of Neurology, University Medical Center, Freiburg, Germany
| | - R Meuli
- Department of Radiology, CHUV, Lausanne, VD, Switzerland
| | - A von Gunten
- Service of Old-Age Psychiatry, Department of Psychiatry, CHUV, Lausanne, VD, Switzerland
| | - G Krueger
- Advanced Clinical Imaging Technology, EPFL, Lausanne, VD, Switzerland ; Heathcare IM S AW, Siemens Schweiz AG, Renens, VD, Switzerland
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46
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Gonyea JV, Watts R, Applebee A, Andrews T, Hipko S, Nickerson JP, Thornton L, Filippi CG. In vivo quantitative whole‐brain T
1
rho MRI of multiple sclerosis. J Magn Reson Imaging 2015; 42:1623-30. [DOI: 10.1002/jmri.24954] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 05/04/2015] [Accepted: 05/05/2015] [Indexed: 11/12/2022] Open
Affiliation(s)
- Jay V. Gonyea
- Department of RadiologyUniversity of Vermont College of MedicineBurlington Vermont USA
| | - Richard Watts
- Department of RadiologyUniversity of Vermont College of MedicineBurlington Vermont USA
| | - Angela Applebee
- Department of Neurological SciencesUniversity of Vermont College of MedicineBurlington Vermont USA
| | - Trevor Andrews
- Department of RadiologyUniversity of Vermont College of MedicineBurlington Vermont USA
- Philips HealthTechCleveland Ohio USA
| | - Scott Hipko
- Department of RadiologyUniversity of Vermont College of MedicineBurlington Vermont USA
| | - Joshua P. Nickerson
- Department of RadiologyUniversity of Vermont College of MedicineBurlington Vermont USA
| | - Lindsay Thornton
- Department of RadiologyUniversity of FloridaGainesville Florida USA
| | - Christopher G. Filippi
- Department of Neurological SciencesUniversity of Vermont College of MedicineBurlington Vermont USA
- Department of RadiologyNorth Shore University Hospital‐Long Island JewishNew York New York USA
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47
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Wassef SN, Wemmie J, Johnson CP, Johnson H, Paulsen JS, Long JD, Magnotta VA. T1ρ imaging in premanifest Huntington disease reveals changes associated with disease progression. Mov Disord 2015; 30:1107-14. [PMID: 25820773 DOI: 10.1002/mds.26203] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 01/23/2015] [Accepted: 01/26/2015] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Imaging biomarkers sensitive to Huntington's disease (HD) during the premanifest phase preceding motor diagnosis may accelerate identification and evaluation of potential therapies. For this purpose, quantitative MRI sensitive to tissue microstructure and metabolism may hold great potential. We investigated the potential value of T1ρ relaxation to detect pathological changes in premanifest HD (preHD) relative to other quantitative relaxation parameters. METHODS Quantitative MR parametric mapping was used to assess differences between 50 preHD subjects and 26 age- and sex-matched controls. Subjects with preHD were classified into two progression groups based on their CAG-age product (CAP) score; a high and a low/moderate CAP group. Voxel-wise and region-of-interest analyses were used to assess changes in the quantitative relaxation times. RESULTS T1ρ showed a significant increase in the relaxation times in the high-CAP group, as compared to controls, largely in the striatum. The T1ρ changes in the preHD subjects showed a significant relationship with CAP score. No significant changes in T2 or T2* relaxation times were found in the striatum. T2* relaxation changes were found in the globus pallidus, but no significant changes with disease progression were found. CONCLUSION These data suggest that quantitative T1ρ mapping may provide a useful marker for assessing disease progression in HD. The absence of T2 changes suggests that the T1ρ abnormalities are unlikely owing to altered water content or tissue structure. The established sensitivity of T1ρ to pH and glucose suggests that these factors are altered in HD perhaps owing to abnormal mitochondrial function.
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Affiliation(s)
- Shafik N Wassef
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA.,SINAPSE, Iowa Neuroimaging Consortium, Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA
| | - John Wemmie
- Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA.,Department of Neurosurgery, University of Iowa, Iowa City, Iowa, USA.,Veterans Affairs Hospital Center, Iowa City, IA, USA
| | - Casey P Johnson
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA
| | - Hans Johnson
- SINAPSE, Iowa Neuroimaging Consortium, Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA
| | - Jane S Paulsen
- Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA.,Department of Neurology, University of Iowa, Iowa City, Iowa, USA.,Department of Psychology, University of Iowa, Iowa City, Iowa, USA
| | - Jeffrey D Long
- Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA.,Department of Biostatistics, University of Iowa, Iowa City, Iowa, USA
| | - Vincent A Magnotta
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA.,Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA.,Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
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48
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Yee S, Gao JH. Effects of spin-lock field direction on the quantitative measurement of spin-lattice relaxation time constant in the rotating frame (T1ρ) in a clinical MRI system. Med Phys 2014; 41:122301. [PMID: 25471977 DOI: 10.1118/1.4900607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate whether the direction of spin-lock field, either parallel or antiparallel to the rotating magnetization, has any effect on the spin-lock MRI signal and further on the quantitative measurement of T1ρ, in a clinical 3 T MRI system. METHODS The effects of inverted spin-lock field direction were investigated by acquiring a series of spin-lock MRI signals for an American College of Radiology MRI phantom, while the spin-lock field direction was switched between the parallel and antiparallel directions. The acquisition was performed for different spin-locking methods (i.e., for the single- and dual-field spin-locking methods) and for different levels of clinically feasible spin-lock field strength, ranging from 100 to 500 Hz, while the spin-lock duration was varied in the range from 0 to 100 ms. RESULTS When the spin-lock field was inverted into the antiparallel direction, the rate of MRI signal decay was altered and the T1ρ value, when compared to the value for the parallel field, was clearly different. Different degrees of such direction-dependency were observed for different spin-lock field strengths. In addition, the dependency was much smaller when the parallel and the antiparallel fields are mixed together in the dual-field method. CONCLUSIONS The spin-lock field direction could impact the MRI signal and further the T1ρ measurement in a clinical MRI system.
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Affiliation(s)
- Seonghwan Yee
- Department of Radiation Oncology, Beaumont Health System, Royal Oak, Michigan 48073
| | - Jia-Hong Gao
- Center for MRI Research, Peking University, Beijing 100871, China
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49
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Allkemper T, Sagmeister F, Cicinnati V, Beckebaum S, Kooijman H, Kanthak C, Stehling C, Heindel W. Evaluation of fibrotic liver disease with whole-liver T1ρ MR imaging: a feasibility study at 1.5 T. Radiology 2013; 271:408-15. [PMID: 24475807 DOI: 10.1148/radiol.13130342] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE To test at 1.5 T whether T1ρ magnetic resonance (MR) imaging of fibrotic liver disease is feasible, to investigate whether liver T1ρ imaging allows assessment of the severity of liver cirrhosis, and to assess the normal liver T1ρ range in healthy patients. MATERIALS AND METHODS This prospective study was approved by the institutional ethics committee. Written informed consent was obtained. Healthy volunteers (n = 25) and patients (n = 34) with cirrhosis underwent whole-liver T1ρ MR imaging at 1.5 T. Mean T1ρ values were calculated from liver regions of interest. Mean T1ρ values were correlated to clinical data and histopathologic analysis by analysis of variance. Receiver operating characteristic curves were calculated to determine the accuracy of mean T1ρ values for the assessment of Child-Pugh class. RESULTS Mean T1ρ values of volunteers (mean, 40.9 msec ± 2.9 [standard deviation]; range, 33.9-46.3 msec) were significantly lower than those of patients who were Child-Pugh class A (P < .004), B (P < .001), or C (P < .001), and significant differences were found between each Child-Pugh stage (A vs B, P < .002; B vs C, P < .009; A vs C, P < .001). Liver cirrhosis was confirmed via histologic analysis in all patients with liver biopsy. Mean T1ρ values did not correlate with necroinflammatory activity (r = 0.31; P = .23), degree of steatosis (r = -0.016; P = .68), or presence of iron load (r = 0.22; P = .43). Mean T1ρ values performed well by assessing the Child-Pugh stage, with receiver operating characteristic areas of 0.95-0.98. Intraclass correlation coefficient values ranged between 0.890 and 0.987, which indicated excellent imaging and reimaging reproducibility and interobserver and intraobserver variability. CONCLUSION Whole-liver T1ρ MR imaging at 1.5 T to detect and assess human liver cirrhosis is feasible. Further investigation and optimization of this technique are warranted to cover the entire spectrum of fibrotic liver disease.
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Affiliation(s)
- Thomas Allkemper
- From the Departments of Clinical Radiology (T.A., F.S., C.S., W.H.) and Transplant Medicine (V.C., S.B.), University of Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany; Philips Medical Systems, Hamburg, Germany (H.K.); and Fraunhofer MEVIS, Institute for Medical Image Computing, Bremen, Germany (C.K.)
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50
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Watts R, Andrews T, Hipko S, Gonyea JV, Filippi CG. In vivo whole-brain T1-rho mapping across adulthood: Normative values and age dependence. J Magn Reson Imaging 2013; 40:376-82. [DOI: 10.1002/jmri.24358] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/31/2013] [Indexed: 11/08/2022] Open
Affiliation(s)
- Richard Watts
- UVM MRI Center for Biomedical Imaging; University of Vermont College of Medicine; Burlington Vermont USA
- Department of Radiology; Fletcher-Allen Healthcare; Burlington Vermont USA
| | - Trevor Andrews
- UVM MRI Center for Biomedical Imaging; University of Vermont College of Medicine; Burlington Vermont USA
- Department of Radiology; Fletcher-Allen Healthcare; Burlington Vermont USA
- Philips Healthcare; Cleveland Ohio USA
| | - Scott Hipko
- UVM MRI Center for Biomedical Imaging; University of Vermont College of Medicine; Burlington Vermont USA
| | - Jay V. Gonyea
- UVM MRI Center for Biomedical Imaging; University of Vermont College of Medicine; Burlington Vermont USA
| | - Christopher G. Filippi
- UVM MRI Center for Biomedical Imaging; University of Vermont College of Medicine; Burlington Vermont USA
- Department of Radiology; Fletcher-Allen Healthcare; Burlington Vermont USA
- Department of Neurology; Fletcher-Allen Healthcare; Burlington Vermont USA
- Department of Radiology; Columbia University Medical Center; New York USA
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