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Zhao F, Zhou N, Wang JL, Zhou H, Zou LQ, Zhong WX, He J, Zheng CJ, Yan SX, Wáng YXJ. Collagen deposition in the liver is strongly and positively associated with T1rho elongation while fat deposition is associated with T1rho shortening: an experimental study of methionine and choline-deficient (MCD) diet rat model. Quant Imaging Med Surg 2020; 10:2307-2321. [PMID: 33269229 PMCID: PMC7596395 DOI: 10.21037/qims-20-651] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/22/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND A number of questions concerning the histological mechanism of elongated T1rho in liver fibrosis remain unanswered. Using a rat model of non-alcoholic fatty liver disease (NAFLD) induced with methionine and choline-deficient (MCD) diet, the primary aim of this study is to clarify whether collagen deposition per se causes liver T1rho elongation. METHODS There were 45 rats in the NAFLD model group and 8 rats in the control group. NAFLD model rats were fed MCD diet for 1, 2, 4, 6, 8, or 10 weeks, respectively. At the endpoint, the rats had in vivo MRI at 3.0 T and followed by histology. For T1rho data acquisition, a rotary echo spin-lock pulse was implemented in a three-dimensional fast field echo sequence with frequency selective fat suppression. The spin-lock frequency was set to 500 Hz, and the spin-lock times of 5, 10, 40, and 50 ms were used. Liver specimens were processed with hematoxylin-eosin staining for steatosis and inflammation evaluation, and Masson's trichrome staining for collagen visualization. The semiquantitative histopathological evaluation was based on NASH Clinical Research Network criteria. Histomorphometric analysis calculated percentages of fat and collagen accumulations in the livers. RESULTS A strong (r=0.82) and significant (P<0.0001) positive correlation between liver collagen content and liver T1rho was observed. Rats with no or minimal inflammation could have very long T1rho value. Among experimental rats without a positive fibrosis grading, five rats did not have an inflammation score (i.e., had minimal inflammation or no inflammation) while four had a positive inflammation score; the difference in liver T1rho between these two types of rats was minimal. Eight control rat livers and 15 stage-1 fibrosis rat livers were separated by liver T1rho completely. When four subgroups of experiment rats were selected where the liver collagen had a very narrow range within these subgroups, all these four subgroups showed a trend of negative correlation between liver fat and liver T1rho. CONCLUSIONS Collagen deposition in the live strongly contributes to liver T1rho elongation, while fat deposition contributes to T1rho shortening. In a well-controlled experimental setting, T1rho measure alone allows separation of healthy livers and stage-1 liver fibrosis in the MCD rat liver model.
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Affiliation(s)
- Feng Zhao
- Department of Radiation Oncology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Nan Zhou
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Ji-Li Wang
- Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua Zhou
- Department of Radiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Li-Qiu Zou
- Department of Radiology, The Sixth Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Wei-Xiang Zhong
- Department of Pathology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jian He
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Cun-Jing Zheng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Sen-Xiang Yan
- Department of Radiation Oncology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yì Xiáng J. Wáng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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Sharafi A, Baboli R, Zibetti M, Shanbhogue K, Olsen S, Block T, Chandarana H, Regatte R. Volumetric multicomponent T 1ρ relaxation mapping of the human liver under free breathing at 3T. Magn Reson Med 2019; 83:2042-2050. [PMID: 31724246 DOI: 10.1002/mrm.28061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 12/16/2022]
Abstract
PURPOSE To develop a 3D sequence for T1ρ relaxation mapping using radial volumetric encoding (3D-T1ρ -RAVE) and to evaluate the multi relaxation components in the liver of healthy controls and chronic liver disease (CLD) patients. METHODS Fat saturation and T1ρ preparation modules were followed by a train of gradient-echo acquisitions and T1 restoration delay. The series of T1ρ -weighted images were fitted using mono-exponential, bi-exponential, and stretched-exponential models. The repeatability and reproducibility of the proposed technique were evaluated on National Institute of Standards and Technology phantom by calculating the coefficient of variation between test-retest scans on the same scanner and between two different 3T scanners, respectively. Mann-Whitney U-test was performed to assess differences in T1ρ components among patients (n = 3) and a control group (n = 10). RESULTS The phantom study showed an error of 8.9% and 11.5% in mono T2 relaxation time measurement relative to the reference on 2 different scanners. The coefficient of variation for test-retest scans performed on the same scanner was 5.7% and 2.4% for scans performed on 2 scanners. The comparison between healthy controls and CLD patients showed a significant difference (P < .05) in mono relaxation time (P = .002), stretched-exponential relaxation parameter (P = .04). The Akaike information criteria C criterion showed 2.53 ± 0.9% (2.3 ± 0.3% for CLD) of the voxels are bi-exponential while in 65.3 ± 5.8% (81.2 ± 0.06% for CLD) of the liver voxels, the stretched-exponential model was preferred. CONCLUSION The 3D-T1ρ -RAVE sequence allows volumetric, multicomponent T1ρ assessment of the liver during free breathing and can distinguish between healthy volunteers and CLD patients.
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Affiliation(s)
- Azadeh Sharafi
- Department of Radiology, New York University School of Medicine, New York, New York
| | - Rahman Baboli
- Department of Radiology, New York University School of Medicine, New York, New York
| | - Marcelo Zibetti
- Department of Radiology, New York University School of Medicine, New York, New York
| | - Krishna Shanbhogue
- Department of Radiology, New York University School of Medicine, New York, New York
| | - Sonja Olsen
- Department of Medicine, New York University School of Medicine, New York, New York
| | - Tobias Block
- Department of Radiology, New York University School of Medicine, New York, New York.,Department of Radiology, University Hospital Basel, Basel, Switzerland
| | - Hersh Chandarana
- Department of Radiology, New York University School of Medicine, New York, New York
| | - Ravinder Regatte
- Department of Radiology, New York University School of Medicine, New York, New York
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Hu G, Liang W, Wu M, Lai C, Mei Y, Li Y, Xu J, Luo L, Quan X. Comparison of T1 Mapping and T1rho Values with Conventional Diffusion-weighted Imaging to Assess Fibrosis in a Rat Model of Unilateral Ureteral Obstruction. Acad Radiol 2019; 26:22-29. [PMID: 29705280 DOI: 10.1016/j.acra.2018.03.023] [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: 02/08/2018] [Revised: 03/14/2018] [Accepted: 03/19/2018] [Indexed: 12/14/2022]
Abstract
RATIONALE AND OBJECTIVES The aim of this study was to investigate the potential of magnetic resonance imaging (MRI) T1 mapping and T1 relaxation time in the rotating frame (T1rho) for assessment of renal fibrosis in a rat model of unilateral ureteral obstruction (UUO). MATERIALS AND METHODS UUO was created in 36 rats. Six rats were scanned at each of the six time points (on days 0, 1, 3, 5, 10, and 15 after UUO). The contralateral kidneys were examined as controls. Hematoxylin-eosin, Masson's trichrome, and alpha-smooth muscle actin (α-SMA) antibody staining assays were performed. MRI data obtained with a 3.0T scanner were analyzed with α-SMA expression and Masson's staining. RESULTS The T1 relaxation times and T1rho values increased, and the mean apparent diffusion coefficient (ADC) values decreased with time after UUO. Simple regression analysis indicated that the mean ADCs, T1 relaxation times, and T1rho values had strong correlations with the α-SMA expression levels (R2 = 0.34, R2 = 0.66, R2 = 0.71, respectively; P< .001) and positive Masson's staining (R2 = 0.38, R2 = 0.67, R2 = 0.65, respectively; P< .001). CONCLUSIONS The T1 mapping and T1rho parameters had better correlations with α-SMA expression and Masson's staining than ADC values.
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Abstract
Liver fibrosis is a hallmark of chronic liver disease characterized by the excessive accumulation of extracellular matrix proteins. Although liver biopsy is the reference standard for diagnosis and staging of liver fibrosis, it has some limitations, including potential pain, sampling variability, and low patient acceptance. Hence, there has been an effort to develop noninvasive imaging techniques for diagnosis, staging, and monitoring of liver fibrosis. Many quantitative techniques have been implemented on magnetic resonance imaging (MRI) for this indication. The most widely validated technique is magnetic resonance elastography, which aims to measure viscoelastic properties of the liver and relate them to fibrosis stage. Several additional MRI methods have been developed or adapted to liver fibrosis quantification. Diffusion-weighted imaging measures the Brownian motion of water molecules which is restricted by collagen fibers. Texture analysis assesses the changes in the texture of liver parenchyma associated with fibrosis. Perfusion imaging relies on signal intensity and pharmacokinetic models to extract quantitative perfusion parameters. Hepatocellular function, which decreases with increasing fibrosis stage, can be estimated by the uptake of hepatobiliary contrast agents. Strain imaging measures liver deformation in response to physiological motion such as cardiac contraction. T1ρ quantification is an investigational technique, which measures the spin-lattice relaxation time in the rotating frame. This article will review the MRI techniques used in liver fibrosis staging, their advantages and limitations, and diagnostic performance. We will briefly discuss future directions, such as longitudinal monitoring of disease, prediction of portal hypertension, and risk stratification of hepatocellular carcinoma.
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Wáng YXJ, Deng M, Lo GG, Liang D, Yuan J, Chen W. Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers. Acta Radiol 2018; 59:257-265. [PMID: 28679324 DOI: 10.1177/0284185117717764] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique's 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan-rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.
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Affiliation(s)
- Yì Xiáng J Wáng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
| | - Min Deng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
| | - Gladys G Lo
- Department of Diagnostic & Interventional Radiology, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR
| | - Dong Liang
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, PR China
| | - Jing Yuan
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
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Wáng YXJ, Deng M, Lin J, Kwok AWL, Liu EKW, Chen W. Age- and Gender-Associated Liver Physiological T1rho Dynamics Demonstrated with a Clinically Applicable Single-Breathhold Acquisition. SLAS Technol 2017; 23:179-187. [PMID: 29241024 DOI: 10.1177/2472630317747198] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To understand women's and men's physiological ranges of liver T1rho relaxation time measured with a single breathhold black blood sequence, this healthy volunteer study was conducted in 62 women (mean age, 38.9 y; range, 18-75 y) and 34 men (mean age, 44.7 y; range, 24-80 y). Approval from the institutional ethics committee was obtained. Magnetic resonance imaging was performed with a 3.0T scanner with six spin-lock times of 0, 10, 20, 25, 35, and 50 ms and a single breathhold of 12 s per slice acquisition. Six slices were acquired for each examination. The results demonstrated that the female liver T1rho value ranged between 35.07 and 51.97 ms and showed an age-dependent decrease, with younger women having a higher measurement. The male liver T1rho value ranged between 34.94 and 43.39 ms, with no evidential age dependence. Postmenopausal women had similar liver T1rho values as men. For women, there was a trend that the liver T1rho value could be 4% to 5% lower during the menstrual phase than during the nonmenstrual phase. For both women and men, no evidential association was seen between body mass index and liver T1rho.
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Affiliation(s)
- Yì Xiáng J Wáng
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
| | - Min Deng
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
| | - Jiang Lin
- 2 Department of Radiology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Anthony W L Kwok
- 3 Department of Orthopedics and Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
| | - Eric K W Liu
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
| | - Weitian Chen
- 1 Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong SAR
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Quantitative assessment of liver function with whole-liver T1rho mapping at 3.0T. Magn Reson Imaging 2017; 46:75-80. [PMID: 29109053 DOI: 10.1016/j.mri.2017.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 10/20/2017] [Accepted: 10/31/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVES To assess the segmental liver function in healthy subjects and liver cirrhosis (LC) patients with different Child-Pugh grades using whole-liver T1rho mapping at 3.0T. METHODS Thirty-three healthy volunteers and 33 patients with clinically diagnosed LC were examined using a three-dimensional (3D) whole-liver coverage T1rho mapping. T1rho maps were calculated from five respiratory-triggered sequences with different spin-lock durations (0, 10, 20, 40, and 60ms). The patients were classified into group A with Child-Pugh A cirrhosis and group B with Child-Pugh B or C cirrhosis. The hepatic T1rho values in different segments of the healthy volunteers and LC patients were compared, and receiver operating characteristic curves (ROC) were plotted to determine the performance of T1rho. RESULTS The median T1rho value of the patients (Child-Pugh class A: 47.07ms; Child-Pugh classes B and C: 51.09ms) was significantly higher than that of the healthy volunteers (39.37ms, P<0.001). No remarkable variations among different hepatic segments in LC patients with various Child-Pugh grades were found (P>0.05). The T1rho values of the liver parenchyma were significantly correlated with albumin (r=-0.590, P<0.001) and prothrombin time (r=0.601, P<0.001). The T1rho values in patients increased with an increase in the Child-Pugh classification (r=0.574, P<0.001). CONCLUSIONS The whole-liver coverage T1rho sequence at 3.0T was feasible for the assessment of segmental liver function. T1rho relaxation might be a potential biomarker for the estimation of liver function in LC patients.
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Park JE, Han K, Sung YS, Chung MS, Koo HJ, Yoon HM, Choi YJ, Lee SS, Kim KW, Shin Y, An S, Cho HM, Park SH. Selection and Reporting of Statistical Methods to Assess Reliability of a Diagnostic Test: Conformity to Recommended Methods in a Peer-Reviewed Journal. Korean J Radiol 2017; 18:888-897. [PMID: 29089821 PMCID: PMC5639154 DOI: 10.3348/kjr.2017.18.6.888] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 07/28/2017] [Indexed: 12/13/2022] Open
Abstract
Objective To evaluate the frequency and adequacy of statistical analyses in a general radiology journal when reporting a reliability analysis for a diagnostic test. Materials and Methods Sixty-three studies of diagnostic test accuracy (DTA) and 36 studies reporting reliability analyses published in the Korean Journal of Radiology between 2012 and 2016 were analyzed. Studies were judged using the methodological guidelines of the Radiological Society of North America-Quantitative Imaging Biomarkers Alliance (RSNA-QIBA), and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiative. DTA studies were evaluated by nine editorial board members of the journal. Reliability studies were evaluated by study reviewers experienced with reliability analysis. Results Thirty-one (49.2%) of the 63 DTA studies did not include a reliability analysis when deemed necessary. Among the 36 reliability studies, proper statistical methods were used in all (5/5) studies dealing with dichotomous/nominal data, 46.7% (7/15) of studies dealing with ordinal data, and 95.2% (20/21) of studies dealing with continuous data. Statistical methods were described in sufficient detail regarding weighted kappa in 28.6% (2/7) of studies and regarding the model and assumptions of intraclass correlation coefficient in 35.3% (6/17) and 29.4% (5/17) of studies, respectively. Reliability parameters were used as if they were agreement parameters in 23.1% (3/13) of studies. Reproducibility and repeatability were used incorrectly in 20% (3/15) of studies. Conclusion Greater attention to the importance of reporting reliability, thorough description of the related statistical methods, efforts not to neglect agreement parameters, and better use of relevant terminology is necessary.
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Affiliation(s)
- Ji Eun Park
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Kyunghwa Han
- Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Yu Sub Sung
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Mi Sun Chung
- Department of Radiology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06973, Korea
| | - Hyun Jung Koo
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Hee Mang Yoon
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Young Jun Choi
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Seung Soo Lee
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Kyung Won Kim
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Youngbin Shin
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Suah An
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
| | - Hyo-Min Cho
- Korea Research Institute of Standards and Science, Daejeon 34113, Korea
| | - Seong Ho Park
- Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea
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Xie S, Li Q, Cheng Y, Zhang Y, Zhuo Z, Zhao G, Shen W. Impact of Liver Fibrosis and Fatty Liver on T1rho Measurements: A Prospective Study. Korean J Radiol 2017; 18:898-905. [PMID: 29089822 PMCID: PMC5639155 DOI: 10.3348/kjr.2017.18.6.898] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 04/15/2017] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE To investigate the liver T1rho values for detecting fibrosis, and the potential impact of fatty liver on T1rho measurements. MATERIALS AND METHODS This study included 18 healthy subjects, 18 patients with fatty liver, and 18 patients with liver fibrosis, who underwent T1rho MRI and mDIXON collections. Liver T1rho, proton density fat fraction (PDFF) and T2* values were measured and compared among the three groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the T1rho values for detecting liver fibrosis. Liver T1rho values were correlated with PDFF, T2* values and clinical data. RESULTS Liver T1rho and PDFF values were significantly different (p < 0.001), whereas the T2* (p = 0.766) values were similar, among the three groups. Mean liver T1rho values in the fibrotic group (52.6 ± 6.8 ms) were significantly higher than those of healthy subjects (44.9 ± 2.8 ms, p < 0.001) and fatty liver group (45.0 ± 3.5 ms, p < 0.001). Mean liver T1rho values were similar between healthy subjects and fatty liver group (p = 0.999). PDFF values in the fatty liver group (16.07 ± 10.59%) were significantly higher than those of healthy subjects (1.43 ± 1.36%, p < 0.001) and fibrosis group (1.07 ± 1.06%, p < 0.001). PDFF values were similar in healthy subjects and fibrosis group (p = 0.984). Mean T1rho values performed well to detect fibrosis at a threshold of 49.5 ms (area under the ROC curve, 0.855), had a moderate correlation with liver stiffness (r = 0.671, p = 0.012), and no correlation with PDFF, T2* values, subject age, or body mass index (p > 0.05). CONCLUSION T1rho MRI is useful for noninvasive detection of liver fibrosis, and may not be affected with the presence of fatty liver.
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Affiliation(s)
- Shuangshuang Xie
- Department of Radiology, Tianjin First Center Hospital, Tianjin 300192, China
| | - Qing Li
- Department of Radiology, Tianjin First Center Hospital, Tianjin 300192, China
| | - Yue Cheng
- Department of Radiology, Tianjin First Center Hospital, Tianjin 300192, China
| | - Yu Zhang
- Clinical Science, Philips Healthcare, Beijing 100600, China
| | - Zhizheng Zhuo
- Clinical Science, Philips Healthcare, Beijing 100600, China
| | - Guiming Zhao
- Department of Hepatology, Tianjin Second People's Hospital, Tianjin 300192, China
| | - Wen Shen
- Department of Radiology, Tianjin First Center Hospital, Tianjin 300192, China
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Okuaki T, Takayama Y, Nishie A, Ogino T, Obara M, Honda H, Miyati T, Van Cauteren M. T 1ρ mapping improvement using stretched-type adiabatic locking pulses for assessment of human liver function at 3 T. Magn Reson Imaging 2017; 40:17-23. [DOI: 10.1016/j.mri.2017.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/17/2017] [Accepted: 03/25/2017] [Indexed: 11/13/2022]
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Song H, Ruan D, Liu W, Stenger VA, Pohmann R, Fernández-Seara MA, Nair T, Jung S, Luo J, Motai Y, Ma J, Hazle JD, Gach HM. Respiratory motion prediction and prospective correction for free-breathing arterial spin-labeled perfusion MRI of the kidneys. Med Phys 2017; 44:962-973. [PMID: 28074528 DOI: 10.1002/mp.12099] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 12/14/2016] [Accepted: 12/27/2016] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Respiratory motion prediction using an artificial neural network (ANN) was integrated with pseudocontinuous arterial spin labeling (pCASL) MRI to allow free-breathing perfusion measurements in the kidney. In this study, we evaluated the performance of the ANN to accurately predict the location of the kidneys during image acquisition. METHODS A pencil-beam navigator was integrated with a pCASL sequence to measure lung/diaphragm motion during ANN training and the pCASL transit delay. The ANN algorithm ran concurrently in the background to predict organ location during the 0.7-s 15-slice acquisition based on the navigator data. The predictions were supplied to the pulse sequence to prospectively adjust the axial slice acquisition to match the predicted organ location. Additional navigators were acquired immediately after the multislice acquisition to assess the performance and accuracy of the ANN. The technique was tested in eight healthy volunteers. RESULTS The root-mean-square error (RMSE) and mean absolute error (MAE) for the eight volunteers were 1.91 ± 0.17 mm and 1.43 ± 0.17 mm, respectively, for the ANN. The RMSE increased with transit delay. The MAE typically increased from the first to last prediction in the image acquisition. The overshoot was 23.58% ± 3.05% using the target prediction accuracy of ± 1 mm. CONCLUSION Respiratory motion prediction with prospective motion correction was successfully demonstrated for free-breathing perfusion MRI of the kidney. The method serves as an alternative to multiple breathholds and requires minimal effort from the patient.
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Affiliation(s)
- Hao Song
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Dan Ruan
- Departments of Radiation Oncology, Biomedical Physics and Bioengineering, UCLA, Los Angeles, CA, 90095, USA
| | - Wenyang Liu
- Departments of Radiation Oncology, Biomedical Physics and Bioengineering, UCLA, Los Angeles, CA, 90095, USA
| | - V Andrew Stenger
- Department of Medicine, University of Hawai'i at Manoa, Honolulu, HI, 96813, USA
| | - Rolf Pohmann
- High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tubingen, Germany
| | | | - Tejas Nair
- DMC R&D Center, Samsung Electronics Inc., Seocho-gu, 06765, Seoul, Korea
| | - Sungkyu Jung
- Department of Statistics, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Jingqin Luo
- Department of Surgery, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Yuichi Motai
- Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Jingfei Ma
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - John D Hazle
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - H Michael Gach
- Departments of Radiation Oncology and Radiology, Washington University, St. Louis, MO, 63110, USA
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Unal E, Idilman IS, Karçaaltıncaba M. Multiparametric or practical quantitative liver MRI: towards millisecond, fat fraction, kilopascal and function era. Expert Rev Gastroenterol Hepatol 2017; 11:167-182. [PMID: 27937040 DOI: 10.1080/17474124.2017.1271710] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
New advances in liver magnetic resonance imaging (MRI) may enable diagnosis of unseen pathologies by conventional techniques. Normal T1 (550-620 ms for 1.5 T and 700-850 ms for 3 T), T2, T2* (>20 ms), T1rho (40-50 ms) mapping, proton density fat fraction (PDFF) (≤5%) and stiffness (2-3kPa) values can enable differentiation of a normal liver from chronic liver and diffuse diseases. Gd-EOB-DTPA can enable assessment of liver function by using postcontrast hepatobiliary phase or T1 reduction rate (normally above 60%). T1 mapping can be important for the assessment of fibrosis, amyloidosis and copper overload. T1rho mapping is promising for the assessment of liver collagen deposition. PDFF can allow objective treatment assessment in NAFLD and NASH patients. T2 and T2* are used for iron overload determination. MR fingerprinting may enable single slice acquisition and easy implementation of multiparametric MRI and follow-up of patients. Areas covered: T1, T2, T2*, PDFF and stiffness, diffusion weighted imaging, intravoxel incoherent motion imaging (ADC, D, D* and f values) and function analysis are reviewed. Expert commentary: Multiparametric MRI can enable biopsyless diagnosis and more objective staging of diffuse liver disease, cirrhosis and predisposing diseases. A comprehensive approach is needed to understand and overcome the effects of iron, fat, fibrosis, edema, inflammation and copper on MR relaxometry values in diffuse liver disease.
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Affiliation(s)
- Emre Unal
- a Liver Imaging Team, Department of Radiology , Hacettepe University School of Medicine , Ankara , Turkey.,b Department of Radiology , Zonguldak Ataturk State Hospital , Zonguldak , Turkey
| | - Ilkay Sedakat Idilman
- a Liver Imaging Team, Department of Radiology , Hacettepe University School of Medicine , Ankara , Turkey.,c Department of Radiology , Ankara Ataturk Education and Research Hospital , Ankara , Turkey
| | - Muşturay Karçaaltıncaba
- a Liver Imaging Team, Department of Radiology , Hacettepe University School of Medicine , Ankara , Turkey
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Petitclerc L, Sebastiani G, Gilbert G, Cloutier G, Tang A. Liver fibrosis: Review of current imaging and MRI quantification techniques. J Magn Reson Imaging 2016; 45:1276-1295. [PMID: 27981751 DOI: 10.1002/jmri.25550] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/27/2016] [Indexed: 12/13/2022] Open
Abstract
Liver fibrosis is characterized by the accumulation of extracellular matrix proteins such as collagen in the liver interstitial space. All causes of chronic liver disease may lead to fibrosis and cirrhosis. The severity of liver fibrosis influences the decision to treat or the need to monitor hepatic or extrahepatic complications. The traditional reference standard for diagnosis of liver fibrosis is liver biopsy. However, this technique is invasive, associated with a risk of sampling error, and has low patient acceptance. Imaging techniques offer the potential for noninvasive diagnosis, staging, and monitoring of liver fibrosis. Recently, several of these have been implemented on ultrasound (US), computed tomography, or magnetic resonance imaging (MRI). Techniques that assess changes in liver morphology, texture, or perfusion that accompany liver fibrosis have been implemented on all three imaging modalities. Elastography, which measures changes in mechanical properties associated with liver fibrosis-such as strain, stiffness, or viscoelasticity-is available on US and MRI. Some techniques assessing liver shear stiffness have been adopted clinically, whereas others assessing strain or viscoelasticity remain investigational. Further, some techniques are only available on MRI-such as spin-lattice relaxation time in the rotating frame (T1 ρ), diffusion of water molecules, and hepatocellular function based on the uptake of a liver-specific contrast agent-remain investigational in the setting of liver fibrosis staging. In this review, we summarize the key concepts, advantages and limitations, and diagnostic performance of each technique. The use of multiparametric MRI techniques offers the potential for comprehensive assessment of chronic liver disease severity. LEVEL OF EVIDENCE 5 J. MAGN. RESON. IMAGING 2017;45:1276-1295.
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Affiliation(s)
- Léonie Petitclerc
- Department of Radiology, Radio-Oncology and Nuclear Medicine, Université de Montréal, Montreal, Quebec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada
| | - Giada Sebastiani
- Department of Gastroenterology and Hepatology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Guillaume Gilbert
- Department of Radiology, Radio-Oncology and Nuclear Medicine, Université de Montréal, Montreal, Quebec, Canada.,MR Clinical Science, Philips Healthcare Canada, Markham, Ontario, Canada
| | - Guy Cloutier
- Department of Radiology, Radio-Oncology and Nuclear Medicine, Université de Montréal, Montreal, Quebec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada.,Institute of Biomedical Engineering, Université de Montréal, CP 6128, Succursale Centre-ville, Montréal, Québec, Canada.,Laboratory of Biorheology and Medical Ultrasonics, CRCHUM, 900 Saint-Denis, Montréal, Québec, Canada
| | - An Tang
- Department of Radiology, Radio-Oncology and Nuclear Medicine, Université de Montréal, Montreal, Quebec, Canada.,Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, Quebec, Canada.,Institute of Biomedical Engineering, Université de Montréal, CP 6128, Succursale Centre-ville, Montréal, Québec, Canada
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14
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Deng M, Chen SZ, Yuan J, Chan Q, Zhou J, Wáng YXJ. Chemical Exchange Saturation Transfer (CEST) MR Technique for Liver Imaging at 3.0 Tesla: an Evaluation of Different Offset Number and an After-Meal and Over-Night-Fast Comparison. Mol Imaging Biol 2016; 18:274-82. [PMID: 26391991 DOI: 10.1007/s11307-015-0887-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE This study seeks to explore whether chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) can detect liver composition changes between after-meal and over-night-fast statuses. PROCEDURES Fifteen healthy volunteers were scanned on a 3.0-T human MRI scanner in the evening 1.5-2 h after dinner and in the morning after over-night (12-h) fasting. Among them, seven volunteers were scanned twice to assess the scan-rescan reproducibility. Images were acquired at offsets (n = 41, increment = 0.25 ppm) from -5 to 5 ppm using a turbo spin echo (TSE) sequence with a continuous rectangular saturation pulse. Amide proton transfer-weighted (APTw) and GlycoCEST signals were quantified with the asymmetric magnetization transfer ratio (MTRasym) at 3.5 ppm and the total MTRasym integrated from 0.5 to 1.5 ppm from the corrected Z-spectrum, respectively. To explore scan time reduction, CEST images were reconstructed using 31 offsets (with 20% time reduction) and 21 offsets (with 40% time reduction), respectively. RESULTS For reproducibility, GlycoCEST measurements in 41 offsets showed the smallest scan-rescan mean measurements variability, indicated by the lowest mean difference of -0.049% (95% limits of agreement, -0.209 to 0.111%); for APTw, the smallest mean difference was found to be 0.112% (95% limits of agreement, -0.698 to 0.921%) in 41 offsets. Compared with after-meal, both GlycoCEST measurement and APTw measurement under different offset number decreased after 12-h fasting. However, as the offsets number decreased (41 offsets vs. 31 offsets vs. 21 offsets), GlycoCEST map and APTw map became more heterogeneous and noisier. CONCLUSION Our results show that CEST liver imaging at 3.0 T has high sensitivity for fasting.
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Affiliation(s)
- Min Deng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
| | - Shu-Zhong Chen
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR
| | - Jing Yuan
- Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong SAR
| | - Queenie Chan
- MR Clinical Science, Philips Healthcare Greater China, Shanghai, China
| | - Jinyuan Zhou
- Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Yì-Xiáng J Wáng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
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15
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Koon CM, Zhang X, Chen W, Chu ESH, San Lau CB, Wáng YXJ. Black blood T1rho MR imaging may diagnose early stage liver fibrosis: a proof-of-principle study with rat biliary duct ligation model. Quant Imaging Med Surg 2016; 6:353-363. [PMID: 27709071 DOI: 10.21037/qims.2016.08.11] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND To explore black blood T1rho (T1ρ) liver imaging and investigate the earliest stage when biliary duct ligation (BDL) induced liver fibrosis can be diagnosed. METHODS MR was performed at 3 Tesla. A T1ρ prepared 2D fast spin echo (FSE) sequence with acquisition of four spin lock times (TSLs: 1, 10, 30, and 50 msec) and spin-lock frequency of 500 Hz was applied. Inherent black blood effect of FSE and double inversion recovery (DIR) achieved blood signal suppression, and 3 axial sections per liver were obtained. Male Sprague-Dawley rats were scanned at baseline (n=32), and on day-3 (n=13), day-5 (n=11), day-7 (n=10), day-10 (n=4) respectively after BDL. Hematoxylin-eosin (HE) and picrosirius red staining liver histology was obtained at these time points. RESULTS The physiological liver parenchyma T1ρ was 38.38±1.53 msec (range, 36.05-41.53 msec). Liver T1ρ value elevated progressively after BDL. On day-10 after BDL all experimental animals can be separated from normal liver based on T1ρ measurement with lowest value being 42.82 msec. Day-7 and day-10 liver resembled METAVIR stage-F1/F2 fibrosis, and fibrous area counted for 0.22%±0.13% and 0.38%±0.44% of liver parenchyma area, respectively. CONCLUSIONS This study provides the first proof-of-principle that T1ρ might diagnose early stage liver fibrosis.
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Affiliation(s)
- Chi-Man Koon
- Institute of Chinese Medicine, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;; State Key Laboratory of Phytochemistry and Plant Resources in West China, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Xin Zhang
- Institute of Chinese Medicine, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;; State Key Laboratory of Phytochemistry and Plant Resources in West China, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Weitian Chen
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
| | - Eagle Siu Hong Chu
- Institute of Digestive Disease and Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
| | - Clara Bik San Lau
- Institute of Chinese Medicine, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;; State Key Laboratory of Phytochemistry and Plant Resources in West China, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Yì-Xiáng J Wáng
- Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China
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16
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Wang L, Yuan J, Zhang SJ, Gao M, Wang YC, Wang YX, Ju S. MyocardialT1rho mapping of patients with end-stage renal disease and its comparison withT1mapping andT2mapping: A feasibility and reproducibility study. J Magn Reson Imaging 2016; 44:723-31. [PMID: 26889749 DOI: 10.1002/jmri.25188] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/22/2016] [Indexed: 02/02/2023] Open
Affiliation(s)
- Lin Wang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital; Medical School of Southeast University; Nanjing China
| | - Jing Yuan
- Medical Physics and Research Department; Hong Kong Sanatorium & Hospital; Happy Valley Hong Kong SAR China
| | - Shi-Jun Zhang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital; Medical School of Southeast University; Nanjing China
| | - Min Gao
- Department of Nephology, Zhongda Hospital; Medical School of Southeast University; Nanjing China
| | - Yuan-Cheng Wang
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital; Medical School of Southeast University; Nanjing China
| | - Yi-Xiang Wang
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital; the Chinese University of Hong Kong; Shatin Hong Kong SAR China
| | - Shenghong Ju
- Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital; Medical School of Southeast University; Nanjing China
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17
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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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18
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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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Chemical exchange saturation transfer (CEST) MR technique for in-vivo liver imaging at 3.0 tesla. Eur Radiol 2015; 26:1792-800. [PMID: 26334509 DOI: 10.1007/s00330-015-3972-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/04/2015] [Accepted: 08/06/2015] [Indexed: 02/08/2023]
Abstract
PURPOSE To evaluate Chemical Exchange Saturation Transfer (CEST) MRI for liver imaging at 3.0-T. MATERIALS AND METHODS Images were acquired at offsets (n = 41, increment = 0.25 ppm) from -5 to 5 ppm using a TSE sequence with a continuous rectangular saturation pulse. Amide proton transfer-weighted (APTw) and GlycoCEST signals were quantified as the asymmetric magnetization transfer ratio (MTRasym) at 3.5 ppm and the total MTRasym integrated from 0.5 to 1.5 ppm, respectively, from the corrected Z-spectrum. Reproducibility was assessed for rats and humans. Eight rats were devoid of chow for 24 hours and scanned before and after fasting. Eleven rats were scanned before and after one-time CCl4 intoxication. RESULTS For reproducibility, rat liver APTw and GlycoCEST measurements had 95 % limits of agreement of -1.49 % to 1.28 % and -0.317 % to 0.345 %. Human liver APTw and GlycoCEST measurements had 95 % limits of agreement of -0.842 % to 0.899 % and -0.344 % to 0.164 %. After 24 hours, fasting rat liver APTw and GlycoCEST signals decreased from 2.38 ± 0.86 % to 0.67 ± 1.12 % and from 0.34 ± 0.26 % to -0.18 ± 0.37 % respectively (p < 0.05). After CCl4 intoxication rat liver APTw and GlycoCEST signals decreased from 2.46 ± 0.48 % to 1.10 ± 0.77 %, and from 0.34 ± 0.23 % to -0.16 ± 0.51 % respectively (p < 0.05). CONCLUSION CEST liver imaging at 3.0-T showed high sensitivity for fasting as well as CCl4 intoxication. KEY POINTS • CEST MRI of in-vivo liver was demonstrated at clinical 3 T field strength. • After 24-hour fasting, rat liver APTw and GlycoCEST signals decreased significantly. • After CCl4 intoxication both rat liver APTw and GlycoCEST signals decreased significantly. • Good scan-rescan reproducibility of liver CEST MRI was shown in healthy volunteers.
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Pandit P, Rivoire J, King K, Li X. Accelerated T1ρ acquisition for knee cartilage quantification using compressed sensing and data-driven parallel imaging: A feasibility study. Magn Reson Med 2015; 75:1256-61. [PMID: 25885368 DOI: 10.1002/mrm.25702] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/25/2015] [Accepted: 02/27/2015] [Indexed: 01/20/2023]
Abstract
PURPOSE Quantitative T1ρ imaging is beneficial for early detection for osteoarthritis but has seen limited clinical use due to long scan times. In this study, we evaluated the feasibility of accelerated T1ρ mapping for knee cartilage quantification using a combination of compressed sensing (CS) and data-driven parallel imaging (ARC-Autocalibrating Reconstruction for Cartesian sampling). METHODS A sequential combination of ARC and CS, both during data acquisition and reconstruction, was used to accelerate the acquisition of T1ρ maps. Phantom, ex vivo (porcine knee), and in vivo (human knee) imaging was performed on a GE 3T MR750 scanner. T1ρ quantification after CS-accelerated acquisition was compared with non CS-accelerated acquisition for various cartilage compartments. RESULTS Accelerating image acquisition using CS did not introduce major deviations in quantification. The coefficient of variation for the root mean squared error increased with increasing acceleration, but for in vivo measurements, it stayed under 5% for a net acceleration factor up to 2, where the acquisition was 25% faster than the reference (only ARC). CONCLUSION To the best of our knowledge, this is the first implementation of CS for in vivo T1ρ quantification. These early results show that this technique holds great promise in making quantitative imaging techniques more accessible for clinical applications.
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Affiliation(s)
- Prachi Pandit
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Julien Rivoire
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | | | - Xiaojuan Li
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
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21
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Lu PX, Huang H, Yuan J, Zhao F, Chen ZY, Zhang Q, Ahuja AT, Zhou BP, Wáng YXJ. Decreases in molecular diffusion, perfusion fraction and perfusion-related diffusion in fibrotic livers: a prospective clinical intravoxel incoherent motion MR imaging study. PLoS One 2014; 9:e113846. [PMID: 25436458 PMCID: PMC4250077 DOI: 10.1371/journal.pone.0113846] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/02/2014] [Indexed: 12/21/2022] Open
Abstract
Purpose This study was aimed to determine whether pure molecular-based diffusion coefficient (D) and perfusion-related diffusion parameters (perfusion fraction f, perfusion-related diffusion coefficient D*) differ in healthy livers and fibrotic livers through intra-voxel incoherent motion (IVIM) MR imaging. Material and Methods 17 healthy volunteers and 34 patients with histopathologically confirmed liver fibrosis patients (stage 1 = 14, stage 2 = 8, stage 3& 4 = 12, METAVIR grading) were included. Liver MR imaging was performed at 1.5-T. IVIM diffusion weighted imaging sequence was based on standard single-shot DW spin echo-planar imaging, with ten b values of 10, 20, 40, 60, 80, 100, 150, 200, 400, 800 sec/mm2 respectively. Pixel-wise realization and regions-of-interest based quantification of IVIM parameters were performed. Results D, f, and D* in healthy volunteer livers and patient livers were 1.096±0.155 vs 0.917±0.152 (10−3 mm2/s, p = 0.0015), 0.164±0.021 vs 0.123±0.029 (p<0.0001), and 13.085±2.943 vs 9.423±1.737 (10−3 mm2/s, p<0.0001) respectively, all significantly lower in fibrotic livers. As the fibrosis severity progressed, D, f, and D* values decreased, with a trend significant for f and D*. Conclusion Fibrotic liver is associated with lower pure molecular diffusion, lower perfusion volume fraction, and lower perfusion-related diffusion. The decrease of f and D* in the liver is significantly associated liver fibrosis severity.
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Affiliation(s)
- Pu-Xuan Lu
- Department of Radiology, The Shenzhen No. 3 People's Hospital, Guangdong Medical College, Shenzhen, China
| | - Hua Huang
- Department of Radiology, The Shenzhen No. 3 People's Hospital, Guangdong Medical College, Shenzhen, China
| | - Jing Yuan
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| | - Feng Zhao
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| | - Zhi-Yi Chen
- Laboratory of Ultrasound Molecular Imaging, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qinwei Zhang
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| | - Anil T. Ahuja
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| | - Bo-Ping Zhou
- Department of Hepatology, The Shenzhen No. 3 People's Hospital, Guangdong Medical College, Shenzhen, China
| | - Yì-Xiáng J. Wáng
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
- * E-mail:
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22
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Wang L, Regatte RR. T₁ρ MRI of human musculoskeletal system. J Magn Reson Imaging 2014; 41:586-600. [PMID: 24935818 DOI: 10.1002/jmri.24677] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 06/03/2014] [Indexed: 12/21/2022] Open
Abstract
Magnetic resonance imaging (MRI) offers the direct visualization of the human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium, etc. Conventional MRI techniques based on T1 - and T2 -weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage, with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article we focus on cartilage biochemical composition, basic principles of T1ρ MRI, implementation of T1ρ pulse sequences, biochemical validation, and summarize the potential applications of the T1ρ MRI technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we also review the potential advantages, challenges, and future prospects of T1ρ MRI for widespread clinical translation.
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Affiliation(s)
- Ligong Wang
- Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, Suzhou, Jiangsu, China
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Wang YXJ, Yuan J. Evaluation of liver fibrosis with T1ρ MR imaging. Quant Imaging Med Surg 2014; 4:152-5. [PMID: 24914415 DOI: 10.3978/j.issn.2223-4292.2014.04.04] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 04/17/2014] [Indexed: 01/11/2023]
Affiliation(s)
- Yi-Xiang J Wang
- 1 Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China ; 2 CUHK Shenzhen Research Institute, Shenzhen 518057, China
| | - Jing Yuan
- 1 Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China ; 2 CUHK Shenzhen Research Institute, Shenzhen 518057, China
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24
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Zhu Y, Zhang Q, Liu Q, Wang YXJ, Liu X, Zheng H, Liang D, Yuan J. PANDA-T1ρ: Integrating principal component analysis and dictionary learning for fast T1ρ mapping. Magn Reson Med 2014; 73:263-72. [PMID: 24554439 DOI: 10.1002/mrm.25130] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 12/24/2022]
Abstract
PURPOSE Long scanning time greatly hinders the widespread application of spin-lattice relaxation in rotating frame (T1ρ) in clinics. In this study, a novel method is proposed to reconstruct the T1ρ-weighted images from undersampled k-space data and hence accelerate the acquisition of T1ρ imaging. METHODS The proposed approach (PANDA-T1ρ) combined the benefit of PCA and dictionary learning when reconstructing image from undersampled data. Specifically, the PCA transform was first used to sparsify the image series along the parameter direction and then the sparsified images were reconstructed by means of dictionary learning and finally solved the images. A variation of PANDA-T1ρ was also developed for the heavy noise case. Numerical simulation and in vivo experiments were carried out with the accelerating factor from 2 to 4 to verify the performance of PANDA-T1ρ. RESULTS The reconstructed T1ρ maps using the PANDA-T1ρ method were found to be comparable to the reference at all verified acceleration factors. Moreover, the variation exhibited better performance than the original version when the k-space data were contaminated by heavy noise. CONCLUSION PANDA-T1ρ can significantly reduce the scanning time of T1ρ by integrating PCA and dictionary learning and provides better parameter estimation than the state-of-art methods for a fixed acceleration factor.
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Affiliation(s)
- Yanjie Zhu
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China.,Shenzhen Key Laboratory for MRI, Shenzhen, Guangdong, China
| | - Qinwei Zhang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Qiegen Liu
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China.,Shenzhen Key Laboratory for MRI, Shenzhen, Guangdong, China.,Department of Electronic Information Engineering, Nanchang University, Nanchang, Jiangxi, China
| | - Yi-Xiang J Wang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Xin Liu
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China.,Shenzhen Key Laboratory for MRI, Shenzhen, Guangdong, China
| | - Hairong Zheng
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China
| | - Dong Liang
- Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, Guangdong, China.,Shenzhen Key Laboratory for MRI, Shenzhen, Guangdong, China
| | - Jing Yuan
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.,CUHK Shenzhen Research Institute, Shenzhen, Guangdong, China
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25
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Johnson CP, Thedens DR, Magnotta VA. Precision-guided sampling schedules for efficient T1ρ mapping. J Magn Reson Imaging 2014; 41:242-50. [PMID: 24474423 DOI: 10.1002/jmri.24518] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 11/01/2013] [Indexed: 02/02/2023] Open
Abstract
PURPOSE To describe, assess, and implement a simple precision estimation framework for optimization of spin-lock time (TSL) sampling schedules for quantitative T1ρ mapping using a mono-exponential signal model. MATERIALS AND METHODS A method is described for estimating T1ρ precision, and a cost function based on the precision estimates is evaluated to determine efficient TSL sampling schedules. The validity of the framework was tested by imaging a phantom with various sampling schedules and comparing theoretical and experimental precision values. The method utility was demonstrated with in vivo T1ρ mapping of brain tissue using a similar procedure as the phantom experiment. To assist investigators, optimal sampling schedules are tabulated for various tissue types and an online calculator is implemented. RESULTS Theoretical and experimental precision values followed similar trends for both the phantom and in vivo experiments. The mean absolute percentage error (MAPE) of theoretical estimates of T1ρ map signal-to-noise ratio (SNR) was typically 5% in the phantom experiment and 33% in the in vivo demonstration. In both experiments, optimal TSL schedules yielded greater T1ρ map SNR efficiency than typical schedules. CONCLUSION The framework can be used to improve the imaging efficiency of T1ρ mapping protocols and to guide selection of imaging parameters.
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Affiliation(s)
- Casey P Johnson
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA
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26
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Zhao F, Yuan J, Deng M, Lu PX, Ahuja AT, Wang YXJ. Further exploration of MRI techniques for liver T1rho quantification. Quant Imaging Med Surg 2014; 3:308-15. [PMID: 24404445 DOI: 10.3978/j.issn.2223-4292.2013.12.10] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 12/22/2013] [Indexed: 01/20/2023]
Abstract
With biliary duct ligation and CCl4 induced rat liver fibrosis models, recent studies showed that MR T1rho imaging is able to detect liver fibrosis, and the degree of fibrosis is correlated with the degree of elevation of the T1rho measurements, suggesting liver T1rho quantification may play an important role for liver fibrosis early detection and grading. It has also been reported it is feasible to obtain consistent liver T1rho measurement for human subjects at 3 Tesla (3 T), and preliminary clinical data suggest liver T1rho is increased in patients with cirrhosis. In these previous studies, T1rho imaging was used with the rotary-echo spin-lock pulse for T1rho preparation, and number of signal averaging (NSA) was 2. Due to the presence of inhomogeneous B0 field, artifacts may occur in the acquired T1rho-weighted images. The method described by Dixon et al. (Magn Reson Med 1996;36:90-4), which is a hard RF pulse with 135° flip angle and same RF phase as the spin-locking RF pulse is inserted right before and after the spin-locking RF pulse, has been proposed to reduce sensitivity to B0 field inhomogeneity in T1rho imaging. In this study, we compared the images scanned by rotary-echo spin-lock pulse method (sequence 1) and the pulse modified according to Dixon method (sequence 2). When the artifacts occurred in T1rho images, we repeated the same scan until satisfactory. We accepted images if artifact in liver was less than 10% of liver area by visual estimation. When NSA =2, the breath-holding duration for data acquisition of one slice scanning was 8 sec due to a delay time of 6,000 ms for magnetization restoration. If NSA =1, the duration was shortened to be 2 sec. In previous studies, manual region of interest (ROI) analysis of T1rho map was used. In this current study, histogram analysis was also applied to evaluate liver T1rho value on T1rho maps. MRI data acquisition was performed on a 3 T clinical scanner. There were 29 subjects with 61 examinations obtained. Liver T1rho values obtained by sequence 1 (NSA =2) and sequence 2 (NSA =2) showed similar values, i.e., 43.1±2.1 ms (range: 38.6-48.0 ms, n=40 scans) vs. 43.5±2.5 ms (range: 39.0-47.7 ms,
n=12 scans, P=0.74) respectively. For the six volunteers scanned with both sequences in one session, the intraclass correlation coefficient (ICC) was 0.939. Overall, the success rate of obtaining satisfactory images per acquisition was slightly over 50% for both sequence 1 and sequence 2. Satisfactory images can usually be obtained by asking the volunteer subjects to better hold their breath. However, sequence 2 did not increase the scan success rate. For the nine subjects scanned by sequence 2 with both NSA =2 and NSA =1 during one session, the ICC was 0.274, demonstrated poor agreement. T1rho measurement by ROI method and histogram had an ICC of 0.901 (P>0.05), demonstrated very good agreement. We conclude that by including 135° flip angle before and after the spin-locking RF pulse, the rate of artifacts occurring did not decrease. On the other hand, sequence 1 and sequence 2 measured similar T1rho value in healthy liver. While reducing the breath-holding duration significantly, NSA =1 did not offer satisfactory signal-to-noise ratio. Histogram measurement can be adopted for future studies.
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Affiliation(s)
- Feng Zhao
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Jing Yuan
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China; ; Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, Guangdong Province, China
| | - Min Deng
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Pu-Xuan Lu
- Department of Radiology, The Shenzhen Third People's Hospital, Shenzhen, Guangdong Province, China
| | - Anil T Ahuja
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
| | - Yi-Xiang J Wang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong, China
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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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Wang YXJ, Zhao F, Yuan J, Mok GS, Ahuja AT, Griffith JF. Accelerated T1rho relaxation quantification in intervertebral disc using limited spin-lock times. Quant Imaging Med Surg 2013; 3:54-8. [PMID: 23482987 DOI: 10.3978/j.issn.2223-4292.2013.02.09] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 02/24/2013] [Indexed: 11/14/2022]
Abstract
OBJECTIVE T1rho relaxation measurement has the potential to identify early biochemical changes in the intervertebral disc. Traditionally, multiple spin-lock times (SLT), often ~5 SLTs, are used to ensure the accuracy and robustness of T1rho mapping. It will be advantageous to use fewer SLT points if comparable accuracy of T1rho mapping can be achieved. In this study, the feasibility of using 3 SLT points to measure intervertebral disc T1rho relaxation time is explored. MATERIALS AND METHODS The lumbar spine of 12 subjects (age range: 30-75 years, disc =60) were studied on 3-T MRI. For T1rho measurement, a rotary echo spin-lock pulse was implemented in a 3D balanced fast field echo (b-FFE) sequence. Spin-lock frequency was set as 500 Hz and the SLTs of 1, 10, 20, 40, and 60 ms were acquired. T1rho maps were generated by fitting each pixel's intensity as a function of SLT using a non-negative least-square fitting algorithm. Images were analysed in the mid-sagittal section. T1rho maps were re-constructed using all 5 SLT points of 1, 10, 20, 40, and 60 ms, and three SLT points of 1, 20, and 60 ms respectively. ROIs included nucleus pulposus (NP), anterior annulus fibrosus (AF) and posterior annulus fibrosus. Values of anterior AF and posterior AF were averaged as the value for AF. Agreement of T1rho measurements using different SLT points was assessed using intra-class correlation coefficient (ICC) on absolute agreement as well as Bland and Altman plot. RESULTS There was no significant difference for T1rho values by 5-SLT measurement and 3-SLT measurement in both NP (P=0.63) and AF (P=0.31). The ICC for 5-SLT T1rho measurement vs. 3-SLT T1rho measurement was 0.991 and 0.981 respectively for NP and AF T1rho time. The Bland and Altman plots for the comparison showed a mean difference of 3.14 and 1.83 for NP and AF respectively. Polling the T1rho values for NP and AF in 60 discs together, the ICC for 5-SLT T1rho measurement vs. 3-SLT T1rho measurement was 0.993, and the Bland and Altman analysis showed a mean difference of 2.56. CONCLUSIONS This study suggests that adopting 3 SLTs of 1, 20, and 60 ms can be an acceptable alternative for the disc T1rho measurement.
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Affiliation(s)
- Yi-Xiang J Wang
- Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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