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Differentiation of multiple sclerosis lesions and low-grade brain tumors on MRS data: machine learning approaches. Neurol Sci 2021; 42:3389-3395. [PMID: 33411201 DOI: 10.1007/s10072-020-04950-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 11/28/2020] [Indexed: 10/22/2022]
Abstract
Some multiple sclerosis (MS) lesions may have great similarities with neoplastic brain lesions in magnetic resonance (MR) imaging and thus wrong diagnoses may occur. In this study, differentiation of MS and low-grade brain tumors was performed with computer-aided diagnosis (CAD) methods by magnetic resonance spectroscopy (MRS) data. MRS data belonging to 51 MS and 39 low-grade brain tumor patients were obtained. The feature extraction from MRS data was performed by the help of peak integration (PI) and full spectra (FS) methods and the most significant features were identified. For the classification step, artificial neural network (ANN), support vector machine (SVM), and linear discriminant analysis (LDA) methods were used and the differentiation between MS and brain tumor was performed automatically. Examining the results, one can conclude that data which belong to MS and low-grade brain tumor cases were automatically differentiated from each other with the help of ANN with 100% accuracy, 100% sensitivity, and 100% specificity. Using of MR spectroscopy and artificial intelligence methods may be useful as a complementary imaging technique to MR imaging in the differentiation of MS lesions and low-grade brain tumors.
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Dandıl E, Karaca S. Detection of pseudo brain tumors via stacked LSTM neural networks using MR spectroscopy signals. Biocybern Biomed Eng 2021. [DOI: 10.1016/j.bbe.2020.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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EkŞİ Z, ÇakiroĞlu M, Öz C, AralaŞmak A, Karadelİ HH, Özcan ME. Differentiation of relapsing-remitting and secondary progressive multiple sclerosis: a magnetic resonance spectroscopy study based on machine learning. ARQUIVOS DE NEURO-PSIQUIATRIA 2020; 78:789-796. [PMID: 33331515 DOI: 10.1590/0004-282x20200094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 06/04/2020] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Magnetic resonance imaging (MRI) is the most important tool for diagnosis and follow-up in multiple sclerosis (MS). The discrimination of relapsing-remitting MS (RRMS) from secondary progressive MS (SPMS) is clinically difficult, and developing the proposal presented in this study would contribute to the process. OBJECTIVE This study aimed to ensure the automatic classification of healthy controls, RRMS, and SPMS by using MR spectroscopy and machine learning methods. METHODS MR spectroscopy (MRS) was performed on a total of 91 participants, distributed into healthy controls (n=30), RRMS (n=36), and SPMS (n=25). Firstly, MRS metabolites were identified using signal processing techniques. Secondly, feature extraction was performed based on MRS Spectra. N-acetylaspartate (NAA) was the most significant metabolite in differentiating MS types. Lastly, binary classifications (healthy controls-RRMS and RRMS-SPMS) were carried out according to features obtained by the Support Vector Machine algorithm. RESULTS RRMS cases were differentiated from healthy controls with 85% accuracy, 90.91% sensitivity, and 77.78% specificity. RRMS and SPMS were classified with 83.33% accuracy, 81.81% sensitivity, and 85.71% specificity. CONCLUSIONS A combined analysis of MRS and computer-aided diagnosis may be useful as a complementary imaging technique to determine MS types.
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Affiliation(s)
- Ziya EkŞİ
- Sakarya University, Department of Computer Engineering, Sakarya, Turkey
| | - Murat ÇakiroĞlu
- Sakarya University, Department of Mechatronic Engineering, Sakarya, Turkey
| | - Cemil Öz
- Sakarya University, Department of Computer Engineering, Sakarya, Turkey
| | - Ayse AralaŞmak
- Memorial Bahçelievler Hospital, Department of Radiology, Istanbul, Turkey
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Application of MR morphologic, diffusion tensor, and perfusion imaging in the classification of brain tumors using machine learning scheme. Neuroradiology 2019; 61:757-765. [PMID: 30949746 DOI: 10.1007/s00234-019-02195-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 02/27/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE While MRI is the modality of choice for the assessment of patients with brain tumors, differentiation between various tumors based on their imaging characteristics might be challenging due to overlapping imaging features. The purpose of this study was to apply a machine learning scheme using basic and advanced MR sequences for distinguishing different types of brain tumors. METHODS The study cohort included 141 patients (41 glioblastoma, 38 metastasis, 50 meningioma, and 12 primary central nervous system lymphoma). A computer-assisted classification scheme, combining morphologic MRI, perfusion MRI, and DTI metrics, was developed and used for tumor classification. The proposed multistep scheme consists of pre-processing, ROI definition, features extraction, feature selection, and classification. Feature subset selection was performed using support vector machines (SVMs). Classification performance was assessed by leave-one-out cross-validation. Given an ROI, the entire classification process was done automatically via computer and without any human intervention. RESULTS A binary hierarchical classification tree was chosen. In the first step, selected features were chosen for distinguishing glioblastoma from the remaining three classes, followed by separation of meningioma from metastasis and PCNSL, and then to discriminate PCNSL from metastasis. The binary SVM classification accuracy, sensitivity and specificity for glioblastoma, metastasis, meningiomas, and primary central nervous system lymphoma were 95.7, 81.6, and 91.2%; 92.7, 95.1, and 93.6%; 97, 90.8, and 58.3%; and 91.5, 90, and 96.9%, respectively. CONCLUSION A machine learning scheme using data from anatomical and advanced MRI sequences resulted in high-performance automatic tumor classification algorithm. Such a scheme can be integrated into clinical decision support systems to optimize tumor classification.
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Lin MC, Li CZ, Hsieh CC, Hong KT, Lin BJ, Lin C, Tsai WC, Lee CH, Lee MG, Chung TT, Tang CT, Ju DT, Ma HI, Liu MY, Chen YH, Hueng DY. Preoperative grading of intracranial meningioma by magnetic resonance spectroscopy (1H-MRS). PLoS One 2018; 13:e0207612. [PMID: 30452483 PMCID: PMC6242682 DOI: 10.1371/journal.pone.0207612] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 11/02/2018] [Indexed: 11/30/2022] Open
Abstract
Although proton magnetic resonance spectroscopy (1H-MRS) is a common method for the evaluation of intracranial meningiomas, controversy exists regarding which parameter of 1H-MRS best predicts the histopathological grade of an intracranial meningioma. In this study, we evaluated the results of pre-operative 1H-MRS to identify predictive factors for high-grade intracranial meningioma. Thirteen patients with World Health Organization (WHO) grade II-III meningioma (confirmed by pathology) were defined as high-grade; twenty-two patients with WHO grade I meningioma were defined as low-grade. All patients were evaluated by 1H-MRS before surgery. The relationships between the ratios of metabolites (N-acetylaspartate [NAA], creatine [Cr], and choline [Cho]) and the diagnosis of high-grade meningioma were analyzed. According to Mann-Whitney U test analysis, the Cho/NAA ratio in cases of high-grade meningioma was significantly higher than in cases of low-grade meningioma (6.34 ± 7.90 vs. 1.58 ± 0.77, p<0.05); however, there were no differences in age, Cho/Cr, or NAA/Cr. According to conditional inference tree analysis, the optimal cut-off point for the Cho/NAA ration between high-grade and low-grade meningioma was 2.409 (sensitivity = 61.54%; specificity = 86.36%). This analysis of pre-operative 1H-MRS metabolite ratio demonstrated that the Cho/NAA ratio may provide a simple and practical predictive value for high-grade intracranial meningiomas, and may aid neurosurgeons in efforts to design an appropriate surgical plan and treatment strategy before surgery.
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Affiliation(s)
- Meng-Chi Lin
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Department of Surgery, Zuoying Branch, Kaohsiung Arm Force General Hospital, Kaohsiung, Taiwan
| | - Chiao-Zhu Li
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Department of Surgery, Kaohsiung Arm Force General Hospital, Kaohsiung, Taiwan
| | - Chih-Chuan Hsieh
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Department of Surgery, Zuoying Branch, Kaohsiung Arm Force General Hospital, Kaohsiung, Taiwan
| | - Kun-Ting Hong
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Bon-Jour Lin
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chin Lin
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Wen-Chiuan Tsai
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chiao-Hua Lee
- Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Man-Gang Lee
- Department of Surgery, Kaohsiung Arm Force General Hospital, Kaohsiung, Taiwan
| | - Tzu-Tsao Chung
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chi-Tun Tang
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Da-Tong Ju
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-I Ma
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ming-Ying Liu
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yuan-Hao Chen
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Dueng-Yuan Hueng
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
- Department of Biochemistry, National Defense Medical Center, Taipei, Taiwan
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan
- * E-mail:
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Kaur T, Saini BS, Gupta S. An optimal spectroscopic feature fusion strategy for MR brain tumor classification using Fisher Criteria and Parameter-Free BAT optimization algorithm. Biocybern Biomed Eng 2018. [DOI: 10.1016/j.bbe.2018.02.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Lin Y, Yuan F, Chen S. Leptomeningeal carcinomatosis 9 years after nodule resection for pulmonary carcinoma in situ: MRS and pathological studies. J Neurooncol 2017. [PMID: 28631192 DOI: 10.1007/s11060-017-2526-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Yiqi Lin
- Department of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Second Road, Huangpu District, Shanghai, 200025, China
| | - Fei Yuan
- Department of Pathology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Sheng Chen
- Department of Neurology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Second Road, Huangpu District, Shanghai, 200025, China.
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Abrol S, Kotrotsou A, Salem A, Zinn PO, Colen RR. Radiomic Phenotyping in Brain Cancer to Unravel Hidden Information in Medical Images. Top Magn Reson Imaging 2017; 26:43-53. [PMID: 28079714 DOI: 10.1097/rmr.0000000000000117] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Radiomics is a new area of research in the field of imaging with tremendous potential to unravel the hidden information in digital images. The scope of radiology has grown exponentially over the last two decades; since the advent of radiomics, many quantitative imaging features can now be extracted from medical images through high-throughput computing, and these can be converted into mineable data that can help in linking imaging phenotypes with clinical data, genomics, proteomics, and other "omics" information. In cancer, radiomic imaging analysis aims at extracting imaging features embedded in the imaging data, which can act as a guide in the disease or cancer diagnosis, staging and planning interventions for treating patients, monitor patients on therapy, predict treatment response, and determine patient outcomes.
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Affiliation(s)
- Srishti Abrol
- *Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center †Department of Neurosurgery, Baylor College of Medicine ‡Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX
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Abstract
Metabolic imaging enhances understanding of disease metabolisms and holds great potential as a measurement tool for evaluating disease prognosis and treatment effectiveness. Advancement of techniques, such as magnetic resonance spectroscopy, positron emission tomography, and mass spectrometry, allows for improved accuracy for quantification of metabolites and present unique possibilities for use in clinic. This article reviews and discusses literature reports of metabolic imaging in humans published since 2010 according to disease type, including cancer, degenerative disorders, psychiatric disorders, and others, as well as the current application of the various related techniques.
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Affiliation(s)
- Taylor L. Fuss
- Departments of Radiology and Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, 02114 USA
| | - Leo L. Cheng
- Departments of Radiology and Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, 02114 USA
- Corresponding Author: Leo L. Cheng, PhD, 149 13 Street, CNY-6, Charlestown, MA 02129, Ph.617-724-6593, Fax.617-726-5684,
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Nachimuthu DS, Baladhandapani A. Multidimensional texture characterization: on analysis for brain tumor tissues using MRS and MRI. J Digit Imaging 2015; 27:496-506. [PMID: 24496552 DOI: 10.1007/s10278-013-9669-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
This paper investigates the efficacy of automated pattern recognition methods on magnetic resonance data with the objective of assisting radiologists in the clinical diagnosis of brain tissue tumors. In this paper, the sciences of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are combined to improve the accuracy of the classifier, based on the multidimensional co-occurrence matrices to assess the detection of pathological tissues (tumor and edema), normal tissues (white matter - WM and gray matter - GM), and fluid (cerebrospinal fluid - CSF). The results show the ability of the classifier with iterative training to automatically and simultaneously recover tissue-specific spectral and structural patterns and achieve segmentation of tumor and edema and grading of high and low glioma tumor. Here, extreme learning machine - improved particle swarm optimization (ELM-IPSO) neural network classifier is trained with the feature descriptions in brain magnetic resonance (MR) spectra. This has the characteristics of varying the normal spectral pattern associated with tumor patterns along with imaging features. Validation was performed considering 35 clinical studies. The volumetric features extracted from the vectors of this matrix articulate some important elementary structures, which along with spectroscopic metabolite ratios discriminate the tumor grades and tissue classes. The quantitative 3D analysis reveals significant improvement in terms of global accuracy rate for automatic classification in brain tissues and discriminating pathological tumor tissue from structural healthy brain tissue.
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Alic L, Niessen WJ, Veenland JF. Quantification of heterogeneity as a biomarker in tumor imaging: a systematic review. PLoS One 2014; 9:e110300. [PMID: 25330171 PMCID: PMC4203782 DOI: 10.1371/journal.pone.0110300] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 09/15/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Many techniques are proposed for the quantification of tumor heterogeneity as an imaging biomarker for differentiation between tumor types, tumor grading, response monitoring and outcome prediction. However, in clinical practice these methods are barely used. This study evaluates the reported performance of the described methods and identifies barriers to their implementation in clinical practice. METHODOLOGY The Ovid, Embase, and Cochrane Central databases were searched up to 20 September 2013. Heterogeneity analysis methods were classified into four categories, i.e., non-spatial methods (NSM), spatial grey level methods (SGLM), fractal analysis (FA) methods, and filters and transforms (F&T). The performance of the different methods was compared. PRINCIPAL FINDINGS Of the 7351 potentially relevant publications, 209 were included. Of these studies, 58% reported the use of NSM, 49% SGLM, 10% FA, and 28% F&T. Differentiation between tumor types, tumor grading and/or outcome prediction was the goal in 87% of the studies. Overall, the reported area under the curve (AUC) ranged from 0.5 to 1 (median 0.87). No relation was found between the performance and the quantification methods used, or between the performance and the imaging modality. A negative correlation was found between the tumor-feature ratio and the AUC, which is presumably caused by overfitting in small datasets. Cross-validation was reported in 63% of the classification studies. Retrospective analyses were conducted in 57% of the studies without a clear description. CONCLUSIONS In a research setting, heterogeneity quantification methods can differentiate between tumor types, grade tumors, and predict outcome and monitor treatment effects. To translate these methods to clinical practice, more prospective studies are required that use external datasets for validation: these datasets should be made available to the community to facilitate the development of new and improved methods.
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Affiliation(s)
- Lejla Alic
- Biomedical Imaging Group Rotterdam, Department of Radiology and Medical Informatics, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Intelligent Imaging, Netherlands Organization for Applied Scientific Research (TNO), The Hague, The Netherlands
| | - Wiro J. Niessen
- Biomedical Imaging Group Rotterdam, Department of Radiology and Medical Informatics, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- Imaging Physics, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands
| | - Jifke F. Veenland
- Biomedical Imaging Group Rotterdam, Department of Radiology and Medical Informatics, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
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Yang G, Raschke F, Barrick TR, Howe FA. Manifold Learning in MR spectroscopy using nonlinear dimensionality reduction and unsupervised clustering. Magn Reson Med 2014; 74:868-78. [PMID: 25199640 DOI: 10.1002/mrm.25447] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/12/2014] [Accepted: 08/18/2014] [Indexed: 01/03/2023]
Abstract
PURPOSE To investigate whether nonlinear dimensionality reduction improves unsupervised classification of (1) H MRS brain tumor data compared with a linear method. METHODS In vivo single-voxel (1) H magnetic resonance spectroscopy (55 patients) and (1) H magnetic resonance spectroscopy imaging (MRSI) (29 patients) data were acquired from histopathologically diagnosed gliomas. Data reduction using Laplacian eigenmaps (LE) or independent component analysis (ICA) was followed by k-means clustering or agglomerative hierarchical clustering (AHC) for unsupervised learning to assess tumor grade and for tissue type segmentation of MRSI data. RESULTS An accuracy of 93% in classification of glioma grade II and grade IV, with 100% accuracy in distinguishing tumor and normal spectra, was obtained by LE with unsupervised clustering, but not with the combination of k-means and ICA. With (1) H MRSI data, LE provided a more linear distribution of data for cluster analysis and better cluster stability than ICA. LE combined with k-means or AHC provided 91% accuracy for classifying tumor grade and 100% accuracy for identifying normal tissue voxels. Color-coded visualization of normal brain, tumor core, and infiltration regions was achieved with LE combined with AHC. CONCLUSION The LE method is promising for unsupervised clustering to separate brain and tumor tissue with automated color-coding for visualization of (1) H MRSI data after cluster analysis.
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Affiliation(s)
- Guang Yang
- Neurosciences Research Centre, Cardiovascular and Cell Sciences Institute, St. George's University of London, London, UK
| | - Felix Raschke
- Neurosciences Research Centre, Cardiovascular and Cell Sciences Institute, St. George's University of London, London, UK
| | - Thomas R Barrick
- Neurosciences Research Centre, Cardiovascular and Cell Sciences Institute, St. George's University of London, London, UK
| | - Franklyn A Howe
- Neurosciences Research Centre, Cardiovascular and Cell Sciences Institute, St. George's University of London, London, UK
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Svolos P, Kousi E, Kapsalaki E, Theodorou K, Fezoulidis I, Kappas C, Tsougos I. The role of diffusion and perfusion weighted imaging in the differential diagnosis of cerebral tumors: a review and future perspectives. Cancer Imaging 2014; 14:20. [PMID: 25609475 PMCID: PMC4331825 DOI: 10.1186/1470-7330-14-20] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 03/20/2014] [Indexed: 12/31/2022] Open
Abstract
The role of conventional Magnetic Resonance Imaging (MRI) in the detection of cerebral tumors has been well established. However its excellent soft tissue visualization and variety of imaging sequences are in many cases non-specific for the assessment of brain tumor grading. Hence, advanced MRI techniques, like Diffusion-Weighted Imaging (DWI), Diffusion Tensor Imaging (DTI) and Dynamic-Susceptibility Contrast Imaging (DSCI), which are based on different contrast principles, have been used in the clinical routine to improve diagnostic accuracy. The variety of quantitative information derived from these techniques provides significant structural and functional information in a cellular level, highlighting aspects of the underlying brain pathophysiology. The present work, reviews physical principles and recent results obtained using DWI/DTI and DSCI, in tumor characterization and grading of the most common cerebral neoplasms, and discusses how the available MR quantitative data can be utilized through advanced methods of analysis, in order to optimize clinical decision making.
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Tsai SY, Wang WC, Lin YR. Comparison of sagittal and transverse echo planar spectroscopic imaging on the quantification of brain metabolites. J Neuroimaging 2014; 25:167-174. [PMID: 24593139 DOI: 10.1111/jon.12087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 11/25/2013] [Accepted: 12/06/2013] [Indexed: 11/29/2022] Open
Abstract
PURPOSE We quantitatively compared sagittal and transverse echo planar spectroscopic imaging (EPSI) on the quantification of metabolite concentrations with consideration of tissue variation. A quantification strategy is proposed to collect the necessary information for quantification of concentrations in a minimized acquisition time. METHODS Six transverse and six sagittal EPSI data were collected on healthy volunteers. Metabolite concentrations of N-acetyl-aspartate (NAA), total creatine (tCr), total choline (tCho), myo-inositol (mI), and glutamate and glutamine complex (Glx) were quantified using water scaling with partial volume and relaxation correction. Linear regression analysis was performed to extract concentrations in gray matter (GM) and white matter (WM). The inter- and intrasubject coefficients of variance (CV) were estimated. RESULTS Concentrations and fitting errors of sagittal and transverse EPSI were at same level. GM to WM contrast of concentrations was found in NAA, tCr, and tCho. The intersubject CVs revealed greater variability in the sagittal EPSI than in the transverse EPSI. The intrasubject CVs of the transverse EPSI were below 5% for NAA, tCr, and tCho. CONCLUSION We showed that quantified concentrations of sagittal and transverse EPSI after partial volume correction are comparable and reproducible. The proposed quantification strategy can be conveniently adapted into various MRI protocols.
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Affiliation(s)
- Shang-Yueh Tsai
- Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan.,Mind, Brain and Learning Center, National Chengchi University, Taipei, Taiwan
| | - Woan-Chyi Wang
- Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan
| | - Yi-Ru Lin
- Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan
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Differential diagnosis of intracranial meningiomas based on magnetic resonance spectroscopy. Neurol Neurochir Pol 2013; 47:247-55. [PMID: 23821422 DOI: 10.5114/ninp.2013.32998] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND PURPOSE To determine in vivo magnetic resonance spectroscopy (MRS) characteristics of intracranial meningiomas and to assess MRS reliability in meningioma grading and discrimination from tumours of similar radiological appearance, such as lymphomas, schwannomas and haemangiopericytomas. MATERIAL AND METHODS Analysis of spectra of 14 patients with meningiomas, 6 with schwannomas, 2 with lymphomas, 2 with haemangiopericytomas and 17 control spectra taken from healthy hemispheres. RESULTS All the patients with meningiomas had a high Cho signal (long TE). There were very low signals of Naa and Cr in the spectra of 10 patients. A reversed Ala doublet was seen only in 2 cases. Four patients had a negative Lac signal, whereas 3 had high Lac-Lip spectra. Twelve spectra showed high Cho signals (short TE). In one case the Cho signal was extremely low. All spectra displayed a very low Cr signal, but high Glx and Lac-Lip signals. Ala presence was found only in 3 patients. The mean Cho/Cr ratio (PRESS) was 5.97 (1.12 in normal brain, p < 0.05). Lac-Lip was present in all the meningiomas (STEAM). The Ala signal was seen only in 2 spectra with long TE and in 3 sequences of the short TE sequences. There were both β/γ-Glx and α-Glx/glutathione signals in all 14 meningiomas. CONCLUSIONS MRS is unable to discriminate low and high grade meningiomas. The method seems to be helpful in discriminating lymphomas (absent Glx signal), schwannomas (mI signal in the short TE sequences) and haemangiopericytomas (presence of mI band) from meningiomas.
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Bauer S, Wiest R, Nolte LP, Reyes M. A survey of MRI-based medical image analysis for brain tumor studies. Phys Med Biol 2013; 58:R97-129. [PMID: 23743802 DOI: 10.1088/0031-9155/58/13/r97] [Citation(s) in RCA: 301] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
MRI-based medical image analysis for brain tumor studies is gaining attention in recent times due to an increased need for efficient and objective evaluation of large amounts of data. While the pioneering approaches applying automated methods for the analysis of brain tumor images date back almost two decades, the current methods are becoming more mature and coming closer to routine clinical application. This review aims to provide a comprehensive overview by giving a brief introduction to brain tumors and imaging of brain tumors first. Then, we review the state of the art in segmentation, registration and modeling related to tumor-bearing brain images with a focus on gliomas. The objective in the segmentation is outlining the tumor including its sub-compartments and surrounding tissues, while the main challenge in registration and modeling is the handling of morphological changes caused by the tumor. The qualities of different approaches are discussed with a focus on methods that can be applied on standard clinical imaging protocols. Finally, a critical assessment of the current state is performed and future developments and trends are addressed, giving special attention to recent developments in radiological tumor assessment guidelines.
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Affiliation(s)
- Stefan Bauer
- Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.
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