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Hojo E, Sui Y, Shan X, Zheng K, Rossman P, Manduca A, Powell GM, An KN, Zhao KD, Bauer BA, Ehman RL, Yin Z. MR elastography-based slip interface imaging (SII) for functional assessment of myofascial interfaces: A feasibility study. Magn Reson Med 2024; 92:676-687. [PMID: 38523575 PMCID: PMC11142878 DOI: 10.1002/mrm.30087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/26/2024]
Abstract
PURPOSE Abnormal adherence at functional myofascial interfaces is hypothesized as an important phenomenon in myofascial pain syndrome. This study aimed to investigate the feasibility of MR elastography (MRE)-based slip interface imaging (SII) to visualize and assess myofascial mobility in healthy volunteers. METHODS SII was used to assess local shear strain at functional myofascial interfaces in the flexor digitorum profundus (FDP) and thighs. In the FDP, MRE was performed at 90 Hz vibration to each index, middle, ring, and little finger. Two thigh MRE scans were performed at 40 Hz with knees flexed and extended. The normalized octahedral shear strain (NOSS) maps were calculated to visualize myofascial slip interfaces. The entropy of the probability distribution of the gradient NOSS was computed for the two knee positions at the intermuscular interface between vastus lateralis and vastus intermedius, around rectus femoris, and between vastus intermedius and vastus medialis. RESULTS NOSS map depicted distinct functional slip interfaces in the FDP for each finger. Compared to knee flexion, clearer slip interfaces and larger gradient NOSS entropy at the vastus lateralis-vastus intermedius interface were observed during knee extension, where the quadriceps are not passively stretched. This suggests the optimal position for using SII to visualize myofascial slip interface in skeletal muscles is when muscles are not subjected to any additional force. CONCLUSION The study demonstrated that MRE-based SII can visualize and assess myofascial interface mobility in extremities. The results provide a foundation for investigating the hypothesis that myofascial pain syndrome is characterized by changes in the mobility of myofascial interfaces.
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Affiliation(s)
- Emi Hojo
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Yi Sui
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Xiang Shan
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Keni Zheng
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Phillip Rossman
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Garret M. Powell
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Kai-Nan An
- Orthopedics Research, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Kristin D. Zhao
- Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Brent A. Bauer
- General Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Richard L. Ehman
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Ziying Yin
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
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Hirad AA, Mix D, Venkataraman A, Meyers SP, Mahon BZ. Strain concentration drives the anatomical distribution of injury in acute and chronic traumatic brain injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.22.595352. [PMID: 38826417 PMCID: PMC11142169 DOI: 10.1101/2024.05.22.595352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Brain tissue injury caused by mild traumatic brain injury (mTBI) disproportionately concentrates in the midbrain, cerebellum, mesial temporal lobe, and the interface between cortex and white matter at sulcal depths 1-12. The bio-mechanical principles that explain why physical impacts to different parts of the skull translate to common foci of injury concentrated in specific brain structures are unknown. A general and longstanding idea, which has not to date been directly tested in humans, is that different brain regions are differentially susceptible to strain loading11,13-15. We use Magnetic Resonance Elastography (MRE) in healthy participants to develop whole-brain bio-mechanical vulnerability maps that independently define which regions of the brain exhibit disproportionate strain concentration. We then validate those vulnerability maps in a prospective cohort of mTBI patients, using diffusion MRI data collected at three cross-sectional timepoints after injury: acute, sub-acute, chronic. We show that regions that exhibit high strain, measured with MRE, are also the sites of greatest injury, as measured with diffusion MR in mTBI patients. This was the case in acute, subacute, and chronic subgroups of the mTBI cohort. Follow-on analyses decomposed the biomechanical cause of increased strain by showing it is caused jointly by disproportionately higher levels of energy arriving to 'high-strain' structures, as well as the inability of 'high strain' structures to effectively disperse that energy. These findings establish a causal mechanism that explains the anatomy of injury in mTBI based on in vivo rheological properties of the human brain.
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Affiliation(s)
- Adnan A Hirad
- Department of Surgery, University of Rochester Medical Center, Rochester, NY, 1462, USA
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY 14642, USA
- Del Monte Neuroscience Institute, University of Rochester, NY, USA
| | - Doran Mix
- Department of Surgery, University of Rochester Medical Center, Rochester, NY, 1462, USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, 1462
| | - Arun Venkataraman
- Department of Physics and Astronomy, University of Rochester, NY, 14623, USA
| | - Steven P Meyers
- Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY, 1462, USA
- Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 1462, USA
| | - Bradford Z Mahon
- Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 1462, USA
- Department of Psychology, Carnegie Mellon University, Pittsburgh, PA 15206
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15206
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Le Y, Chen J, Rossman P, Bolster B, Kannengiesser S, Manduca A, Glaser K, Sui Y, Huston J, Yin Z, Ehman RL. Wavelet MRE: Imaging propagating broadband acoustic waves with wavelet-based motion-encoding gradients. Magn Reson Med 2024; 91:1923-1935. [PMID: 38098427 PMCID: PMC10950519 DOI: 10.1002/mrm.29972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/24/2023] [Accepted: 11/26/2023] [Indexed: 03/20/2024]
Abstract
PURPOSE To demonstrate a novel MR elastography (MRE) technique, termed here wavelet MRE. With this technique, broadband motion sensitivity is achievable. Moreover, the true tissue displacement can be reconstructed with a simple inverse transform. METHODS A wavelet MRE sequence was developed with motion-encoding gradients based on Haar wavelets. From the phase images' displacement was estimated using an inverse transform. Simulations were performed using a frequency sweep and a transient as ground-truth motions. A PVC phantom was scanned using wavelet MRE and standard MRE with both transient (one and 10 cycles of 90-Hz motion) and steady-state dual-frequency motion (30 and 60 Hz) for comparison. The technique was tested in a human brain, and motion trajectories were estimated for each voxel. RESULTS In simulation, the displacement information estimated from wavelet MRE closely matched the true motion. In the phantom test, the MRE phase data generated from the displacement information derived from wavelet MRE agreed well with standard MRE data. Testing of wavelet MRE to assess transient motion waveforms in the brain was successful, and the tissue motion observed was consistent with a previous study. CONCLUSION The uniform and broadband frequency response of wavelet MRE makes it a promising method for imaging transient, multifrequency motion, or motion with unknown frequency content. One potential application is measuring the response of brain tissue undergoing low-amplitude, transient vibrations as a model for the study of traumatic brain injury.
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Affiliation(s)
- Yuan Le
- Department of Radiology, Mayo Clinic, Rochester, MN
| | - Jun Chen
- Department of Radiology, Mayo Clinic, Rochester, MN
| | | | - Bradley Bolster
- MR Collaborations, Siemens Medical Solutions USA, Inc., Malvern, PA, USA
| | | | | | - Kevin Glaser
- Department of Radiology, Mayo Clinic, Rochester, MN
| | - Yi Sui
- Department of Radiology, Mayo Clinic, Rochester, MN
| | - John Huston
- Department of Radiology, Mayo Clinic, Rochester, MN
| | - Ziying Yin
- Department of Radiology, Mayo Clinic, Rochester, MN
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Shi X, Liu Y, Zhang Z, Tao B, Zhang D, Jiang Q, Chen G, Ma H, Feng Y, Xie J, Zheng X, Zhang J. The value of radiographic features in predicting postoperative facial nerve function in vestibular schwannoma patients: A retrospective study and nomogram analysis. CNS Neurosci Ther 2024; 30:e14526. [PMID: 37990346 PMCID: PMC11017437 DOI: 10.1111/cns.14526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/23/2023] Open
Abstract
OBJECTIVE The purpose of this study was to identify significant prognostic factors associated with facial paralysis after vestibular schwannoma (VS) surgery and develop a novel nomogram for predicting facial nerve (FN) outcomes. METHODS Retrospective data were retrieved from 355 patients who underwent microsurgery via the retrosigmoid approach for VS between December 2017 and December 2022. Univariate and multivariate logistic regression analysis were used to construct a radiographic features-based nomogram to predict the risk of facial paralysis after surgery. RESULTS Following a thorough screening process, a total of 185 participants were included. The univariate and multivariate logistic regression analysis revealed that tumor size (p = 0.005), fundal fluid cap (FFC) sign (p = 0.014), cerebrospinal fluid cleft (CSFC) sign (p < 0.001), and expansion of affected side of internal auditory canal (IAC) (p = 0.033) were independent factors. A nomogram model was constructed based on these indicators. When applied to the validation cohort, the nomogram demonstrated good discrimination and favorable calibration. Then we generated a web-based calculator to facilitate clinical application. CONCLUSION Tumor size, FFC and CSFC sign, and the expansion of the IAC, serve as good predictors of postoperative FN outcomes. Based on these factors, the nomogram model demonstrates good predictive performance.
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Affiliation(s)
- Xudong Shi
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| | - Yuyang Liu
- Department of Neurosurgery920th Hospital of Joint Logistics Support ForceKunmingChina
| | - Zehan Zhang
- Department of Neurosurgerythe Air Force Hospital of Southern Theater CommandGuangzhouChina
| | - Bingyan Tao
- Department of Neurosurgery961th Hospital of Joint Logistics Support ForceQiqiharChina
| | - Ding Zhang
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| | - Qingyu Jiang
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| | - Guilin Chen
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| | - Hengchao Ma
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
- Medical School of Chinese PLABeijingChina
| | - Yaping Feng
- Department of Neurosurgery920th Hospital of Joint Logistics Support ForceKunmingChina
| | - Jiaxin Xie
- Department of Neurosurgery920th Hospital of Joint Logistics Support ForceKunmingChina
| | - Xuan Zheng
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
| | - Jun Zhang
- Department of Neurosurgery, The First Medical CentreChinese PLA General HospitalBeijingChina
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Rasmussen AM, Friismose AI, Mussmann B, Lagerstrand K, Harbo FSG, Jensen J. Repeatability of diffusion-based stiffness prediction - A healthy volunteer study. Radiography (Lond) 2024; 30:524-530. [PMID: 38262191 DOI: 10.1016/j.radi.2024.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 01/25/2024]
Abstract
INTRODUCTION The study investigated the repeatability of brain diffusion-based stiffness prediction (DWIstiff) in healthy volunteers. METHODS Thirty-one healthy volunteers were examined with DWIstiff using two different sets of b-values: b200-1500 s/mm2 (DWIstiff, 1500) and b200-1000 s/mm2 (DWIstiff, 1000). Each b-value set was scanned twice per imaging session without repositioning the participants. DWIstiff images were reconstructed from each set. Two observers delineated regions of interest (ROIs) on each DWIstiff image. The repeatability coefficient (RC), coefficient of variation (CV), inter- and intraobserver agreement were calculated. RESULTS After excluding three participants due to image artifacts, the study included twenty-eight volunteers (mean age (range)) 37 years (24-62), 10 males, 18 females). For DWIstiff, 1500, the lowest and the highest RCs were in the parietal lobe (0.52) and respectively the brain stem (1.17). The lowest RC for DWIstiff, 1000 was in the frontal lobe (0.42) and the highest in the brain stem (1.58). The CV for whole brain measurements was 3.83 % for DWIstiff, 1500 and 4.93 % for DWIstiff, 1000. The Bland‒Altman (BA) limits of agreement (LoA) for the intraobserver agreement of DWIstiff, 1500 were -0.90 to 1.06 and respectively -0.78 to 0.88 for DWIstiff, 1000. Regarding interobserver agreement, the LoA were -0.85 to 0.94 for DWIstiff, 1500 and -0.61 to 0.66 for DWIstiff, 1000. CONCLUSION DWIstiff is a precise technique with some observer dependence. Repeatability is higher for DWIstiff, 1000 s/mm2 than for DWIstiff 1500 s/mm2. IMPLICATIONS FOR PRACTICE Our findings suggest that DWIstiff can reliably detect stiffness changes larger than 4.93 % in healthy volunteers. Further studies should investigate whether the repeatability of DWIstiff may be affected by the presence of pathology such as a brain tumor.
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Affiliation(s)
- A-M Rasmussen
- Department of Radiology, Odense University Hospital, Odense, Denmark; Research and Innovation Unit of Radiology, University of Southern Denmark, Odense, Denmark
| | - A I Friismose
- Department of Radiology, Odense University Hospital, Odense, Denmark; Research and Innovation Unit of Radiology, University of Southern Denmark, Odense, Denmark.
| | - B Mussmann
- Department of Radiology, Odense University Hospital, Odense, Denmark; Research and Innovation Unit of Radiology, University of Southern Denmark, Odense, Denmark; Department of Life Sciences and Health, Radiography, Oslo Metropolitan University, Oslo, Norway
| | - K Lagerstrand
- Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden; Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - F S G Harbo
- Department of Radiology, Odense University Hospital, Odense, Denmark
| | - J Jensen
- Department of Radiology, Odense University Hospital, Odense, Denmark; Research and Innovation Unit of Radiology, University of Southern Denmark, Odense, Denmark
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Ahmed ANA. Preoperative Magnetic Resonance Elastography (MRE) of Skull Base Tumours: A Review. Indian J Otolaryngol Head Neck Surg 2023; 75:4173-4178. [PMID: 37974805 PMCID: PMC10645913 DOI: 10.1007/s12070-023-03955-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/08/2023] [Indexed: 11/19/2023] Open
Abstract
Conventional magnetic resonance imaging (MRI) can detect tumors consistency, but it can't predict tumor stiffness or adherence of the tumor to nearby structures. Magnetic resonance elastography (MRE) is a known non-invasive MRI based imaging technique used to assess the viscoelasticity of the tissues particularly liver fibrosis. This study discussed the importance of preoperative MRE in skull base tumors and the future implications of this new imaging modality. We did review of the English literature (by searching PubMed) regarding the use of MRE in preoperative assessment of skull base tumours stiffness and adherence to surrounding tissues. Recent research demonstrated that MRE can detect the stiffness and adherence of skull base tumors to surrounding structures by recording the spread of mechanical waves in the different tissues. In addition to non-radiation exposure, this technique is fast and can be incorporated into the conventional (MRI) study. MRE can palpate skull base tumours by imaging, allowing the stiffness of the tumour to be assessed. Preoperative assessment of brain tumours consistency, stiffness, and adherence to surrounding tissues is critical to avoid injury of important nearby structures and better preoperative patient counselling regarding surgical approach (endoscopic or open), operative time, and suspected surgical complications. However, the accuracy of MRE is less in small and highly vascular tumors. Also, MRE can't accurately detect tumour-brain adherence, but the new modality (slip-interface imaging) can. Hence, adding MRE to the conventional MRI study may help in preoperative diagnosis and treatment of skull base tumours.
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Affiliation(s)
- Ahmed Nabil Abdelhamid Ahmed
- Department of Otorhinolaryngology, Faculty of Medicine, Ain Shams University, 6th Nile Valley Street, Hadayek Alkoba, Cairo, 11331 Egypt
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Liu X, Wang Y, Han T, Liu H, Zhou J. Preoperative surgical risk assessment of meningiomas: a narrative review based on MRI radiomics. Neurosurg Rev 2022; 46:29. [PMID: 36576657 DOI: 10.1007/s10143-022-01937-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/08/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
Meningiomas are one of the most common intracranial primary central nervous system tumors. Regardless of the pathological grading and histological subtypes, maximum safe resection is the recommended treatment option for meningiomas. However, considering tumor heterogeneity, surgical treatment options and prognosis often vary greatly among meningiomas. Therefore, an accurate preoperative surgical risk assessment of meningiomas is of great clinical importance as it helps develop surgical treatment strategies and improve patient prognosis. In recent years, an increasing number of studies have proved that magnetic resonance imaging (MRI) radiomics has wide application values in the diagnostic, identification, and prognostic evaluations of brain tumors. The vital importance of MRI radiomics in the surgical risk assessment of meningiomas must be apprehended and emphasized in clinical practice. This narrative review summarizes the current research status of MRI radiomics in the preoperative surgical risk assessment of meningiomas, focusing on the applications of MRI radiomics in preoperative pathological grading, assessment of surrounding tissue invasion, and evaluation of tumor consistency. We further analyze the prospects of MRI radiomics in the preoperative assessment of meningiomas angiogenesis and adhesion with surrounding tissues, while pointing out the current challenges of MRI radiomics research.
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Affiliation(s)
- Xianwang Liu
- Department of Radiology, Lanzhou University Second Hospital, Chengguan District, Cuiyingmen No.82, Lanzhou, 730030, People's Republic of China
- Second Clinical School, Lanzhou University, Lanzhou, People's Republic of China
- Key Laboratory of Medical Imaging of Gansu Province, Lanzhou, People's Republic of China
- Gansu International Scientific and Technological Cooperation Base of Medical Imaging Artificial Intelligence, Lanzhou, People's Republic of China
| | - Yuzhu Wang
- Second Clinical School, Lanzhou University, Lanzhou, People's Republic of China
- Key Laboratory of Medical Imaging of Gansu Province, Lanzhou, People's Republic of China
| | - Tao Han
- Department of Radiology, Lanzhou University Second Hospital, Chengguan District, Cuiyingmen No.82, Lanzhou, 730030, People's Republic of China
- Second Clinical School, Lanzhou University, Lanzhou, People's Republic of China
- Key Laboratory of Medical Imaging of Gansu Province, Lanzhou, People's Republic of China
- Gansu International Scientific and Technological Cooperation Base of Medical Imaging Artificial Intelligence, Lanzhou, People's Republic of China
| | - Hong Liu
- Department of Radiology, Lanzhou University Second Hospital, Chengguan District, Cuiyingmen No.82, Lanzhou, 730030, People's Republic of China
- Second Clinical School, Lanzhou University, Lanzhou, People's Republic of China
- Key Laboratory of Medical Imaging of Gansu Province, Lanzhou, People's Republic of China
- Gansu International Scientific and Technological Cooperation Base of Medical Imaging Artificial Intelligence, Lanzhou, People's Republic of China
| | - Junlin Zhou
- Department of Radiology, Lanzhou University Second Hospital, Chengguan District, Cuiyingmen No.82, Lanzhou, 730030, People's Republic of China.
- Second Clinical School, Lanzhou University, Lanzhou, People's Republic of China.
- Key Laboratory of Medical Imaging of Gansu Province, Lanzhou, People's Republic of China.
- Gansu International Scientific and Technological Cooperation Base of Medical Imaging Artificial Intelligence, Lanzhou, People's Republic of China.
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Li Y, Gao Q, Chen N, Zhang Y, Wang J, Li C, He X, Jiao Y, Zhang Z. Clinical studies of magnetic resonance elastography from 1995 to 2021: Scientometric and visualization analysis based on CiteSpace. Quant Imaging Med Surg 2022; 12:5080-5100. [PMID: 36330182 PMCID: PMC9622435 DOI: 10.21037/qims-22-207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/11/2022] [Indexed: 02/05/2023]
Abstract
BACKGROUND To assess the knowledge framework around magnetic resonance elastography (MRE) and to explore MRE research hotspots and emerging trends. METHODS The Science Citation Index Expanded of the Web of Science Core Collection was searched on 22 October 2021 for MRE-related studies published between 1995 and 2021. Excel 2016 and CiteSpace V (version 5.8.R3) were used to analyze the downloaded data. RESULTS In all, 1,236 articles published by 726 authors from 540 institutions in 40 countries were included in this study. The top 10 authors published 57.6% of all included articles. The 3 most productive countries were the USA (n=631), Germany (n=202), and France (n=134), and the 3 most productive institutions were the Mayo Clinic (n=240), Charité (n=131), and the University of Illinois (n=56). The USA and the Mayo Clinic had the highest betweenness centrality among countries and institutions, respectively, and played an important role in the field of MRE. In this study, the 24,347 distinct references were clustered into 48 categories via reasonable clustering using specific keywords, forming the knowledge framework. Among the 294 co-occurring keywords, "hepatic fibrosis", "stiffness", "skeletal muscle", "acoustic strain wave", "in vivo", and "non-invasive assessment" were research hotspots. "Diagnostic performance", "diagnostic accuracy", "hepatic steatosis", "chronic hepatitis B", "radiation force impulse", "children", and "echo" were frontier topics. CONCLUSIONS Scientometric and visualized analysis of MRE can provide information regarding the knowledge framework, research hotspots, frontier areas, and emerging trends in this field.
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Affiliation(s)
- Youwei Li
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Qiang Gao
- Department of Gastroenterology and Hepatology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Na Chen
- Department of Otorhinolaryngology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Yuanfang Zhang
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Juan Wang
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Chang Li
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Xuan He
- Department of Radiology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Yang Jiao
- Department of Rehabilitation Psychology, Beijing Rehabilitation Hospital, Capital Medical University, Beijing, China
| | - Zongming Zhang
- Department of General Surgery, Beijing Electric Power Hospital, State Grid Corporation of China, Capital Medical University, Beijing, China
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Hersh AM, Weber-Levine C, Jiang K, Young L, Kerensky M, Routkevitch D, Tsehay Y, Perdomo-Pantoja A, Judy BF, Lubelski D, Theodore N, Manbachi A. Applications of elastography in operative neurosurgery: A systematic review. J Clin Neurosci 2022; 104:18-28. [PMID: 35933785 PMCID: PMC11023619 DOI: 10.1016/j.jocn.2022.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/30/2022]
Abstract
Elastography is an imaging technology capable of measuring tissue stiffness and consistency. The technology has achieved widespread use in the workup and management of diseases of the liver, breast, thyroid, and prostate. Although elastography is increasingly being applied in neurosurgery, it has not yet achieved widespread adoption and many clinicians remain unfamiliar with the technology. Therefore, we sought to summarize the range of applications and elastography modalities available for neurosurgery, report its effectiveness in comparison with conventional imaging methods, and offer recommendations. All full-text English-language manuscripts on the use of elastography for neurosurgical procedures were screened using the PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science databases. Thirty-two studies were included with 990 patients, including 21 studies on intracranial tumors, 5 on hydrocephalus, 4 on epilepsy, 1 on spinal cord compression, and 1 on adolescent scoliosis. Twenty studies used ultrasound elastography (USE) whereas 12 used magnetic resonance elastography (MRE). MRE studies were mostly used in the preoperative setting for assessment of lesion stiffness, tumor-brain adherence, diagnostic workup, and operative planning. USE studies were performed intraoperatively to guide resection of lesions, determine residual microscopic abnormalities, assess the tumor-brain interface, and study mechanical properties of tumors. Elastography can assist with resection of brain tissue, detection of microscopic lesions, and workup of hydrocephalus, among other applications under investigation. Its sensitivity often exceeds that of conventional MRI and ultrasound for identifying abnormal tissue and lesion margins.
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Affiliation(s)
- Andrew M Hersh
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Carly Weber-Levine
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Kelly Jiang
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Lisa Young
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Max Kerensky
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Denis Routkevitch
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Yohannes Tsehay
- Department of Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
| | | | - Brendan F Judy
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Daniel Lubelski
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Nicholas Theodore
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| | - Amir Manbachi
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Sun Y, Yang J, Li T, Gao K, Tong X. Nomogram for Predicting Facial Nerve Outcomes After Surgical Resection of Vestibular Schwannoma. Front Neurol 2022; 12:817071. [PMID: 35211077 PMCID: PMC8860821 DOI: 10.3389/fneur.2021.817071] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 12/28/2021] [Indexed: 11/24/2022] Open
Abstract
Objective The facial nerve (FN) outcomes after vestibular schwannoma surgery seriously affect the social psychology and quality of life of patients. More and more attention has been paid to the protection of FN function. This study aimed to identify significant prognostic factors for FN outcomes after vestibular schwannoma surgery and create a new nomogram for predicting the rates of poor FN outcomes. Methods Data from patients who had undergone operations for vestibular schwannoma between 2015 and 2020 were retrieved retrospectively and patients were divided into good and poor FN outcomes groups according to postoperative nerve function. The nomogram for predicting the risk of poor FN outcomes was constructed from the results of the univariate logistic regression analysis and the multivariate logistic regression analysis of the influencing factors for FN outcomes after surgical resection of vestibular schwannoma. Results A total of 392 participants were enrolled. The univariate logistic regression analysis revealed that age, tumor size, cystic features of tumors, cerebrospinal fluid (CSF) cleft sign, tumor adhesion to the nerve, learning curve, and FN position were statistically significant. The multivariate logistic regression analysis showed that age, tumor size, cystic features of tumors, CSF cleft sign, tumor adhesion to the nerve, learning curve, and FN position were independent factors. The nomogram model was constructed according to these indicators. At the last follow-up examination, a good FN outcome was observed in 342 patients (87.2%) and only 50 patients (12.8%) was presented with poor FN function. Application of the nomogram in the validation cohort still gave good discrimination [area under the curve (AUC), 0.806 (95% CI, 0.752–0.861)] and good calibration. Conclusion This study has presented a reliable and valuable nomogram that can accurately predict the occurrence of poor FN outcomes after surgery in patients. This tool is easy to use and could assist doctors in establishing clinical decision-making for individual patients.
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Affiliation(s)
- Yang Sun
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin, China
| | - Jianhua Yang
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin, China
| | - Tang Li
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin, China
| | - Kaiming Gao
- Department of Neurosurgery, Tianjin Huanhu Hospital, Tianjin, China
| | - Xiaoguang Tong
- Clinical College of Neurology, Neurosurgery and Neurorehabilitation, Tianjin Medical University, Tianjin, China.,Department of Neurosurgery, Tianjin Huanhu Hospital, Tianjin, China
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11
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Li M, Yin Z, Hu B, Guo N, Zhang L, Zhang L, Zhu J, Chen W, Yin M, Chen J, Ehman RL, Wang J. MR Elastography-Based Shear Strain Mapping for Assessment of Microvascular Invasion in Hepatocellular Carcinoma. Eur Radiol 2022; 32:5024-5032. [PMID: 35147777 DOI: 10.1007/s00330-022-08578-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 12/17/2022]
Abstract
OBJECTIVES To evaluate the potential of MR elastography (MRE)-based shear strain mapping to noninvasively predict the presence of microvascular invasion (MVI) in hepatocellular carcinoma (HCC). METHODS Fifty-nine histopathology-proven HCC patients with conventional 60-Hz MRE examinations (+/-MVI, n = 34/25) were enrolled retrospectively between December 2016 and October 2019, with one subgroup comprising 29/59 patients (+/-MVI, n = 16/13) who also underwent 40- and 30-Hz MRE examinations. Octahedral shear strain (OSS) maps were calculated, and the percentage of peritumoral interface length with low shear strain (i.e., a low-shear-strain length, pLSL, %) was recorded. For OSS-pLSL, differences between the MVI (+) and MVI (-) groups and diagnostic performance at different MRE frequencies were analyzed using the Mann-Whitney test and area under the receiver operating characteristic curve (AUC), respectively. RESULTS The peritumor OSS-pLSL was significantly higher in the MVI (+) group than in the MVI (-) group at the three frequencies (all p < 0.01). The AUC of peritumor OSS-pLSL for predicting MVI was good/excellent in all frequency groups (60-Hz: 0.73 (n = 59)/0.80 (n = 29); 40-Hz: 0.84; 30-Hz: 0.90). On further analysis of the 29 cases with all frequencies, the AUCs were not significantly different. As the frequency decreased from 60-Hz, the specificity of OSS increased at 40-Hz (53.8-61.5%) and further increased at 30-Hz (53.8-76.9%), and the sensitivity remained high at lower frequencies (100.0-93.8%) (all p > 0.05). CONCLUSIONS MRE-based shear strain mapping is a promising technique for noninvasively predicting the presence of MVI in patients with HCC, and the most recommended frequency for OSS is 30-Hz. KEY POINTS • MR elastography (MRE)-based shear strain mapping has the potential to predict the presence of microvascular invasion (MVI) in hepatocellular carcinoma preoperatively. • The low interface shear strain identified at tumor-liver boundaries was highly correlated with the presence of MVI.
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Affiliation(s)
- Mengsi Li
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Ziying Yin
- Department of Radiology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Bing Hu
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Ning Guo
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Linqi Zhang
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Lina Zhang
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Jie Zhu
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Wenying Chen
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Meng Yin
- Department of Radiology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Jun Chen
- Department of Radiology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Richard L Ehman
- Department of Radiology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Jin Wang
- Department of Radiology, the Third Affiliated Hospital, Sun Yat-Sen University (SYSU), No 600, Tianhe Road, Guangzhou, Guangdong, 510630, People's Republic of China.
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12
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Abstract
BACKGROUND Magnetic resonance elastography (MRE) allows noninvasive assessment of intracranial tumor mechanics and may thus be predictive of intraoperative conditions. Variations in the use of technical terms complicate reading of current literature, and there is need of a review using consolidated nomenclature. OBJECTIVES We present an overview of current literature on MRE relating to human intracranial neoplasms using standardized nomenclature suggested by the MRE guidelines committee. We then discuss the implications of the findings, and suggest approaches for future research. METHOD We performed a systematic literature search in PubMed, Embase, and Web of Science; the articles were screened for relevance and then subjected to full text review. Technical terms were consolidated. RESULTS We identified 12 studies on MRE in patients with intracranial tumors, including meningiomas, glial tumors including glioblastomas, vestibular schwannomas, hemangiopericytoma, central nervous system lymphoma, pituitary macroadenomas, and brain metastases. The studies had varying objectives that included prediction of intraoperative consistency, histological separation, prediction of adhesiveness, and exploration of the mechanobiology of tumor invasiveness and malignancy. The technical terms were translated using standardized nomenclature. The literature was highly heterogeneous in terms of image acquisition techniques, post-processing, and study design and was generally limited by small and variable cohorts. CONCLUSIONS MRE shows potential in predicting tumor consistency, adhesion, and mechanical homogeneity. Furthermore, MRE provides insight into malignant tumor behavior and its relation to tissue mechanics. MRE is still at a preclinical stage, but technical advances, improved understanding of soft tissue rheological impact, and larger samples are likely to enable future clinical introduction.
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13
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Lilaj L, Herthum H, Meyer T, Shahryari M, Bertalan G, Caiazzo A, Braun J, Fischer T, Hirsch S, Sack I. Inversion-recovery MR elastography of the human brain for improved stiffness quantification near fluid-solid boundaries. Magn Reson Med 2021; 86:2552-2561. [PMID: 34184306 DOI: 10.1002/mrm.28898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 05/10/2021] [Accepted: 06/02/2021] [Indexed: 12/31/2022]
Abstract
PURPOSE In vivo MR elastography (MRE) holds promise as a neuroimaging marker. In cerebral MRE, shear waves are introduced into the brain, which also stimulate vibrations in adjacent CSF, resulting in blurring and biased stiffness values near brain surfaces. We here propose inversion-recovery MRE (IR-MRE) to suppress CSF signal and improve stiffness quantification in brain surface areas. METHODS Inversion-recovery MRE was demonstrated in agar-based phantoms with solid-fluid interfaces and 11 healthy volunteers using 31.25-Hz harmonic vibrations. It was performed by standard single-shot, spin-echo EPI MRE following 2800-ms IR preparation. Wave fields were acquired in 10 axial slices and analyzed for shear wave speed (SWS) as a surrogate marker of tissue stiffness by wavenumber-based multicomponent inversion. RESULTS Phantom SWS values near fluid interfaces were 7.5 ± 3.0% higher in IR-MRE than MRE (P = .01). In the brain, IR-MRE SNR was 17% lower than in MRE, without influencing parenchymal SWS (MRE: 1.38 ± 0.02 m/s; IR-MRE: 1.39 ± 0.03 m/s; P = .18). The IR-MRE tissue-CSF interfaces appeared sharper, showing 10% higher SWS near brain surfaces (MRE: 1.01 ± 0.03 m/s; IR-MRE: 1.11 ± 0.01 m/s; P < .001) and 39% smaller ventricle sizes than MRE (P < .001). CONCLUSIONS Our results show that brain MRE is affected by fluid oscillations that can be suppressed by IR-MRE, which improves the depiction of anatomy in stiffness maps and the quantification of stiffness values in brain surface areas. Moreover, we measured similar stiffness values in brain parenchyma with and without fluid suppression, which indicates that shear wavelengths in solid and fluid compartments are identical, consistent with the theory of biphasic poroelastic media.
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Affiliation(s)
- Ledia Lilaj
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Helge Herthum
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Tom Meyer
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Mehrgan Shahryari
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Gergely Bertalan
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Alfonso Caiazzo
- Weierstrass Institute for Applied Analysis and Stochastics, Berlin, Germany
| | - Jürgen Braun
- Institute of Medical Informatics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas Fischer
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sebastian Hirsch
- Berlin Center for Advanced Neuroimaging, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Ingolf Sack
- Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
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14
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Teixeira BCDA, Constanzo F, Sens P, Ramina R, Escuissato DL. Brainstem hyperintensity in patients with vestibular schwannoma is associated with labyrinth signal on magnetic resonance imaging but not vestibulocochlear tests. Neuroradiol J 2021; 34:180-186. [PMID: 33325805 PMCID: PMC8165906 DOI: 10.1177/1971400920980165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Focal hyperintensity in the dorsal brainstem (HDB) has been described in large cerebellopontine angle tumours and is thought to represent vestibular nuclei degeneration, but its functional significance has not been thoroughly investigated. Our aim was to analyse its relationship to imaging characteristics of the tumour and inner-ear structures and to vestibulocochlear functional tests. METHODS We retrospectively reviewed 54 patients with a histological diagnosis of vestibular schwannoma (VS). Magnetic resonance imaging tumour characteristics (size, cystic composition and distance from the cochlear aperture), signal intensity ratio of the cochlea and vestibule in fluid-attenuated inversion recovery (FLAIR) and fast imaging employing steady-state acquisition (FIESTA)/fast spin-echo imaging with variable flip angles (CUBE) and vestibulocochlear function tests (audiometry, auditory brainstem response (ABR) and video head impulse testing (vHIT)) were obtained. Statistical analyses were performed to evaluate their relation to focal HDB. RESULTS Focal HDB was found in 22% of VS. It was significantly associated with large (p < 0.001) and cystic (p = 0.004) tumours and also with tumours located further from the cochlear aperture (p = 0.039). The signal intensity ratio of the cochlea on FLAIR was higher in patients with HDB (p < 0.014), but this difference was not observed in FIESTA/CUBE (p = 0.981). Audiometry, ABR and vHIT results did not significantly differ in patients with HDB, but ABR results were worse in patients with higher cochlear signal intensity on FLAIR sequences (p = 0.026). CONCLUSIONS Focal HDB in patients with VS was associated with increased signal intensity ratio of the cochlea on FLAIR in patients with VS but not directly to the results of vestibulocochlear function tests.
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Affiliation(s)
- Bernardo Corrêa de Almeida Teixeira
- Department of Neuroradiology, Neurological Institute of Curitiba (INC), Brazil
- Department of Internal Medicine, Federal University of Paraná (UFPR), Brazil
| | - Felipe Constanzo
- Department of Neurosurgery, Neurological Institute of Curitiba (INC), Brazil
| | - Patricia Sens
- Department of Otorhinolaryngology, Neurological Institute of Curitiba (INC), Brazil
| | - Ricardo Ramina
- Department of Neurosurgery, Neurological Institute of Curitiba (INC), Brazil
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15
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Yin Z, Lu X, Cohen Cohen S, Sui Y, Manduca A, Van Gompel JJ, Ehman RL, Huston J. A new method for quantification and 3D visualization of brain tumor adhesion using slip interface imaging in patients with meningiomas. Eur Radiol 2021; 31:5554-5564. [PMID: 33852045 DOI: 10.1007/s00330-021-07918-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 02/12/2021] [Accepted: 03/19/2021] [Indexed: 01/02/2023]
Abstract
OBJECTIVES To develop an objective quantitative method to characterize and visualize meningioma-brain adhesion using MR elastography (MRE)-based slip interface imaging (SII). METHODS This retrospective study included 47 meningiomas (training dataset: n = 35; testing dataset: n = 12) with MRE/SII examinations. Normalized octahedral shear strain (NOSS) values were calculated from the acquired MRE displacement data. The change in NOSS at the tumor boundary (ΔNOSSbdy) was computed, from which a 3D ΔNOSSbdy map of the tumor surface was created and the probability distribution of ΔNOSSbdy over the entire tumor surface was calculated. Statistical features were calculated from the probability histogram. After eliminating highly correlated features, the capability of the remaining feature for tumor adhesion classification was assessed using a one-way ANOVA and ROC analysis. RESULTS The magnitude and location of the tumor adhesion can be visualized by the reconstructed 3D ΔNOSSbdy surface map. The entropy of the ΔNOSSbdy histogram was significantly different between adherent tumors and partially/completely non-adherent tumors in both the training (AUC: 0.971) and testing datasets (AUC: 0.900). Based on the cutoff values obtained from the training set, the ΔNOSSbdy entropy in the testing dataset yielded an accuracy of 0.83 for distinguishing adherent versus partially/non-adherent tumors, and 0.67 for distinguishing non-adherent versus completely/partially adherent tumors. CONCLUSIONS SII-derived ΔNOSSbdy values are useful for quantification and classification of meningioma-brain adhesion. The reconstructed 3D ΔNOSSbdy surface map presents the state and location of tumor adhesion in a "clinician-friendly" manner, and can identify meningiomas with a high risk of adhesion to adjacent brain parenchyma. KEY POINTS • MR elastography (MRE)-based slip interface imaging shows promise as an objective tool to preoperatively discriminate meningiomas with a high risk of intraoperative adhesion. • Measurement of the change of shear strain at meningioma boundaries can provide quantitative metrics depicting the state of adhesion at the tumor-brain interface. • The surface map of tumor adhesion shows promise in assisting precise adhesion localization, using a comprehensible, "clinician-friendly" 3D visualization.
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Affiliation(s)
- Ziying Yin
- Department of Radiology, Mayo Clinic, 200 First St SW, Opus 2-149, Rochester, MN, 55905, USA.
| | - Xin Lu
- Department of Radiology, Mayo Clinic, 200 First St SW, Opus 2-149, Rochester, MN, 55905, USA
| | | | - Yi Sui
- Department of Radiology, Mayo Clinic, 200 First St SW, Opus 2-149, Rochester, MN, 55905, USA
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Jamie J Van Gompel
- Department of Neurosurgery, Mayo Clinic, Rochester, MN, USA.,Department of Otorhinolaryngology, Mayo Clinic, Rochester, MN, USA
| | - Richard L Ehman
- Department of Radiology, Mayo Clinic, 200 First St SW, Opus 2-149, Rochester, MN, 55905, USA
| | - John Huston
- Department of Radiology, Mayo Clinic, 200 First St SW, Opus 2-149, Rochester, MN, 55905, USA
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16
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Arani A, Manduca A, Ehman RL, Huston Iii J. Harnessing brain waves: a review of brain magnetic resonance elastography for clinicians and scientists entering the field. Br J Radiol 2021; 94:20200265. [PMID: 33605783 PMCID: PMC8011257 DOI: 10.1259/bjr.20200265] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Brain magnetic resonance elastography (MRE) is an imaging technique capable of accurately and non-invasively measuring the mechanical properties of the living human brain. Recent studies have shown that MRE has potential to provide clinically useful information in patients with intracranial tumors, demyelinating disease, neurodegenerative disease, elevated intracranial pressure, and altered functional states. The objectives of this review are: (1) to give a general overview of the types of measurements that have been obtained with brain MRE in patient populations, (2) to survey the tools currently being used to make these measurements possible, and (3) to highlight brain MRE-based quantitative biomarkers that have the highest potential of being adopted into clinical use within the next 5 to 10 years. The specifics of MRE methodology strategies are described, from wave generation to material parameter estimations. The potential clinical role of MRE for characterizing and planning surgical resection of intracranial tumors and assessing diffuse changes in brain stiffness resulting from diffuse neurological diseases and altered intracranial pressure are described. In addition, the emerging technique of functional MRE, the role of artificial intelligence in MRE, and promising applications of MRE in general neuroscience research are presented.
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Affiliation(s)
- Arvin Arani
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Armando Manduca
- Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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17
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Herthum H, Dempsey SCH, Samani A, Schrank F, Shahryari M, Warmuth C, Tzschätzsch H, Braun J, Sack I. Superviscous properties of the in vivo brain at large scales. Acta Biomater 2021; 121:393-404. [PMID: 33326885 DOI: 10.1016/j.actbio.2020.12.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 12/28/2022]
Abstract
There is growing awareness that brain mechanical properties are important for neural development and health. However, published values of brain stiffness differ by orders of magnitude between static measurements and in vivo magnetic resonance elastography (MRE), which covers a dynamic range over several frequency decades. We here show that there is no fundamental disparity between static mechanical tests and in vivo MRE when considering large-scale properties, which encompass the entire brain including fluid filled compartments. Using gradient echo real-time MRE, we investigated the viscoelastic dispersion of the human brain in, so far, unexplored dynamic ranges from intrinsic brain pulsations at 1 Hz to ultralow-frequency vibrations at 5, 6.25, 7.8 and 10 Hz to the normal frequency range of MRE of 40 Hz. Surprisingly, we observed variations in brain stiffness over more than two orders of magnitude, suggesting that the in vivo human brain is superviscous on large scales with very low shear modulus of 42±13 Pa and relatively high viscosity of 6.6±0.3 Pa∙s according to the two-parameter solid model. Our data shed light on the crucial role of fluid compartments including blood vessels and cerebrospinal fluid (CSF) for whole brain properties and provide, for the first time, an explanation for the variability of the mechanical brain responses to manual palpation, local indentation, and high-dynamic tissue stimulation as used in elastography.
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18
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MR Elastography. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00058-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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19
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Ariyurek C, Tasdelen B, Ider YZ, Atalar E. SNR Weighting for Shear Wave Speed Reconstruction in Tomoelastography. NMR IN BIOMEDICINE 2021; 34:e4413. [PMID: 32956538 DOI: 10.1002/nbm.4413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 08/31/2020] [Accepted: 09/06/2020] [Indexed: 06/11/2023]
Abstract
In tomoelastography, to achieve a final wave speed map by combining reconstructions obtained from all spatial directions and excitation frequencies, the use of weights is inevitable. Here, a new weighting scheme, which maximizes the signal-to-noise ratio (SNR) of the final wave speed map, has been proposed. To maximize the SNR of the final wave speed map, the use of squares of estimated SNR values of reconstructed individual maps has been proposed. Therefore, derivations of the SNR of the reconstructed wave speed maps have become necessary. Considering the noise on the complex MRI signal, the SNR of the reconstructed wave speed map was formulated by an analytical approach assuming a high SNR, and the results were verified using Monte Carlo simulations (MCSs). It has been assumed that the noise remains approximately Gaussian when the image SNR is high enough, despite the nonlinear operations in tomoelastography inversion. Hence, the SNR threshold was determined by comparing the SNR computed by MCSs and analytical approximations. The weighting scheme was evaluated for accuracy, spatial resolution and SNR performances on simulated phantoms. MR elastography (MRE) experiments on two different phantoms were conducted. Wave speed maps were generated for simulated 3D human abdomen MRE data and experimental human abdomen MRE data. The simulation results demonstrated that the SNR-weighted inversion improved the SNR performance of the wave speed map by a factor of two compared to the performance of the original (i.e., amplitude-weighted) reconstruction. In the case of a low SNR, no bias occurred in the wave speed map when SNR weighting was used, whereas 10% bias occurred when the original weighting (i.e., amplitude weighting) was used. Thus, while not altering the accuracy or spatial resolution of the wave speed map with the proposed weighting method, the SNR of the wave speed map has been significantly improved.
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Affiliation(s)
- Cemre Ariyurek
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Bilal Tasdelen
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
| | - Yusuf Ziya Ider
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
| | - Ergin Atalar
- Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
- National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey
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20
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MR elastography of liver: current status and future perspectives. Abdom Radiol (NY) 2020; 45:3444-3462. [PMID: 32705312 DOI: 10.1007/s00261-020-02656-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 07/06/2020] [Accepted: 07/09/2020] [Indexed: 02/08/2023]
Abstract
Non-invasive evaluation of liver fibrosis has evolved over the last couple of decades. Currently, elastography techniques are the most widely used non-invasive methods for clinical evaluation of chronic liver disease (CLD). MR elastography (MRE) of the liver has been used in the clinical practice for nearly a decade and continues to be widely accepted for detection and staging of liver fibrosis. With MRE, one can directly visualize propagating shear waves through the liver and an inversion algorithm in the scanner automatically converts the shear wave properties into an elastogram (stiffness map) on which liver stiffness can be calculated. The commonly used MRE method, two-dimensional gradient recalled echo (2D-GRE) sequence has produced excellent results in the evaluation of liver fibrosis in CLD from various etiologies and newer clinical indications continue to emerge. Advances in MRE technique, including 3D MRE, automated liver elasticity calculation, improvements in shear wave delivery and patient experience, are promising to provide a faster and more reliable MRE of liver. Innovations, including evaluation of mechanical parameters, such as loss modulus, displacement, and volumetric strain, are promising for comprehensive evaluation of CLD as well as understanding pathophysiology, and in differentiating various etiologies of CLD. In this review, the current status of the MRE of liver in CLD are outlined and followed by a brief description of advanced techniques and innovations in MRE of liver.
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Li J, Venkatesh SK, Yin M. Advances in Magnetic Resonance Elastography of Liver. Magn Reson Imaging Clin N Am 2020; 28:331-340. [PMID: 32624152 DOI: 10.1016/j.mric.2020.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Magnetic resonance elastography (MRE) is the most accurate noninvasive technique in diagnosing fibrosis and cirrhosis in patients with chronic liver disease (CLD). The accuracy of hepatic MRE in distinguishing the severity of disease has been validated in studies of patients with various CLDs. Advanced hepatic MRE is a reliable, comfortable, and inexpensive alternative to liver biopsy for disease diagnosing, progression monitoring, and clinical decision making in patients with CLDs. This article summarizes current knowledge of the technical advances and innovations in hepatic MRE, and the clinical applications in various hepatic diseases.
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Affiliation(s)
- Jiahui Li
- Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA
| | | | - Meng Yin
- Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA.
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22
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Eliezer M, Poillon G, Maquet C, Gillibert A, Horion J, Marie JP, Guichard JP, Magne N, Attyé A. Sensorineural hearing loss in patients with vestibular schwannoma correlates with the presence of utricular hydrops as diagnosed on heavily T2-weighted MRI. Diagn Interv Imaging 2019; 100:259-268. [PMID: 30773403 DOI: 10.1016/j.diii.2019.01.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/08/2019] [Accepted: 01/13/2019] [Indexed: 12/31/2022]
Abstract
PURPOSE The purpose of this study was to assess whether the volume of the vestibular endolymphatic space correlates with the degree of hearing loss using heavily T2-weighted fast imaging employing steady-state acquisition with cycle phase (FIESTA-C) MRI. MATERIALS AND METHODS A total of 23 patients with vestibular schwannoma, as diagnosed on typical image findings, who underwent FIESTA-C MRI were included. There were 13 women and 10 men with a mean age of 63.5±9.3 (SD) years (range: 49-88years). Two radiologists independently evaluated the volume of the utricle and saccule. Correlation between tumor volume, vestibular endolymphatic space volume and degree of hearing loss - as evaluated with the levels of pure-tone average and speech recognition threshold - were searched for. RESULTS The mean saccular, utricular and tumor volumes were 3.17±1.1 (SD) mm3 (range: 1.45-5.7mm3), 14.55±5 (SD) mm3; (range: 6.6-23.9mm3) and 17.4±5.5 (SD) mm3; (range: 8.3-25.4mm3), respectively. There was a moderate correlation between the volume of the utricle and the degree of hearing loss as evaluated with the levels of pure-tone average (rho=0.5; P=0.015) and speech recognition threshold (rho=0.58; P=0.004). There were no significant correlations between saccular and tumor volumes and the degree of hearing loss. CONCLUSION The volume of the utricle in patients with obstructive vestibular schwannoma moderately correlates with the degree of hearing loss.
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Affiliation(s)
- M Eliezer
- Department of Neuroradiology, Rouen University Hospital, 76000 Rouen, France; Department of Neuroradiology, Hôpital Lariboisière, 75010 Paris, France.
| | - G Poillon
- Department of Neuroradiology, Rouen University Hospital, 76000 Rouen, France
| | - C Maquet
- Department of Head And Neck Surgery, Rouen University Hospital, 76000 Rouen, France
| | - A Gillibert
- Department of Biostatistics, Rouen University Hospital, 76000 Rouen, France
| | - J Horion
- Department of Neuroradiology, Rouen University Hospital, 76000 Rouen, France
| | - J-P Marie
- Department of Head And Neck Surgery, Rouen University Hospital, 76000 Rouen, France
| | - J-P Guichard
- Department of Neuroradiology, Hôpital Lariboisière, 75010 Paris, France
| | - N Magne
- Department of Neuroradiology, Rouen University Hospital, 76000 Rouen, France
| | - A Attyé
- Department of Neuroradiology, Rouen University Hospital, 76000 Rouen, France; Department of Neuroradiology and MRI, Grenoble Alpes University Hospital, SFR RMN neurosciences, 38000 Grenoble, France
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Bertalan G, Guo J, Tzschätzsch H, Klein C, Barnhill E, Sack I, Braun J. Fast tomoelastography of the mouse brain by multifrequency single‐shot MR elastography. Magn Reson Med 2018; 81:2676-2687. [DOI: 10.1002/mrm.27586] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 10/04/2018] [Accepted: 10/07/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Gergely Bertalan
- Department of Radiology Charité–Universitätsmedizin Berlin, Campus Charité MitteBerlin Germany
| | - Jing Guo
- Department of Radiology Charité–Universitätsmedizin Berlin, Campus Charité MitteBerlin Germany
| | - Heiko Tzschätzsch
- Department of Radiology Charité–Universitätsmedizin Berlin, Campus Charité MitteBerlin Germany
| | - Charlotte Klein
- Department of Neurology Charité–Universitätsmedizin Berlin, Campus Charité MitteBerlin Germany
| | - Eric Barnhill
- Department of Radiology Charité–Universitätsmedizin Berlin, Campus Charité MitteBerlin Germany
| | - Ingolf Sack
- Department of Radiology Charité–Universitätsmedizin Berlin, Campus Charité MitteBerlin Germany
| | - Jürgen Braun
- Institute of Medical Informatics Charité–Universitätsmedizin Berlin, Campus Benjamin FranklinBerlin Germany
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Yin Z, Romano AJ, Manduca A, Ehman RL, Huston J. Stiffness and Beyond: What MR Elastography Can Tell Us About Brain Structure and Function Under Physiologic and Pathologic Conditions. Top Magn Reson Imaging 2018; 27:305-318. [PMID: 30289827 PMCID: PMC6176744 DOI: 10.1097/rmr.0000000000000178] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Brain magnetic resonance elastography (MRE) was developed on the basis of a desire to "palpate by imaging" and is becoming a powerful tool in the investigation of neurophysiological and neuropathological states. Measurements are acquired with a specialized MR phase-contrast pulse sequence that can detect tissue motion in response to an applied external or internal excitation. The tissue viscoelasticity is then reconstructed from the measured displacement. Quantitative characterization of brain viscoelastic behaviors provides us an insight into the brain structure and function by assessing the mechanical rigidity, viscosity, friction, and connectivity of brain tissues. Changes in these features are associated with inflammation, demyelination, and neurodegeneration that contribute to brain disease onset and progression. Here, we review the basic principles and limitations of brain MRE and summarize its current neuroanatomical studies and clinical applications to the most common neurosurgical and neurodegenerative disorders, including intracranial tumors, dementia, multiple sclerosis, amyotrophic lateral sclerosis, and traumatic brain injury. Going forward, further improvement in acquisition techniques, stable inverse reconstruction algorithms, and advanced numerical, physical, and preclinical validation models is needed to increase the utility of brain MRE in both research and clinical applications.
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Affiliation(s)
- Ziying Yin
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN
| | | | - Armando Manduca
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN
- Departments of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN
| | - Richard L. Ehman
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN
| | - John Huston
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN
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Abstract
The mechanical properties of soft tissues are closely associated with a variety of diseases. This motivates the development of elastography techniques in which tissue mechanical properties are quantitatively estimated through imaging. Magnetic resonance elastography (MRE) is a noninvasive phase-contrast MR technique wherein shear modulus of soft tissue can be spatially and temporally estimated. MRE has recently received significant attention due to its capability in noninvasively estimating tissue mechanical properties, which can offer considerable diagnostic potential. In this work, recent technology advances of MRE, its future clinical applications, and the related limitations will be discussed.
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Affiliation(s)
- Huiming Dong
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Richard D. White
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Arunark Kolipaka
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, 43210, USA
- Department of Internal Medicine-Division of Cardiology, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
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Lokesh B, Ten Dam AM, de Korte CL, Thittai AK. Understanding the Contrast Mechanism in Rotation Elastogram: A Parametric Study. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1860-1872. [PMID: 29801975 DOI: 10.1016/j.ultrasmedbio.2018.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 06/08/2023]
Abstract
Ultrasound elastography has been found to be useful in different clinical applications. For example, in breast imaging, axial strain elastography provides information related to tissue stiffness, which is used to characterize breast lesions as either benign or malignant. In addition, these lesions also differ in their bonding properties. Benign breast lesions are loosely bonded and malignant breast lesions are firmly bonded to the surrounding tissues. Therefore, only benign breast lesions will rotate/slip on the application of deformation. This rotation of lesions can be visualized with rotation elastography, which utilizes axial and lateral shear strain components. The contrast obtained in rotation elastography depends on various mechanical as well as ultrasound elastography parameters. However, there is no reported work that provides an understanding of the influence of these parameters on the visualized rotation contrast. In this work, the authors studied the rotation contrast by varying the mechanical parameters such as the inclusion b/a ratio, relative inclusion-background Young's modulus, amount of applied deformation and orientation of the inclusion. First, the authors performed finite-element analysis to understand the fundamental rotation contrast of the inclusion. Next, rotation elastograms obtained from ultrasound simulations in Field II and experiments on tissue-mimicking phantoms were investigated. Mean contrast was used as a metric to evaluate the quality of rotation elastograms in finite-element analysis, and contrast-to-noise ratio was used in Field II simulations and phantom experiments. The results indicate that rotation contrast was observed only in the case of loosely bonded inclusions. Further, the rotation contrast was found to depend on the inclusion asymmetry and its orientation with respect to the axis of deformation. Interestingly, it was found that a loosely bonded inclusion contrasts with surrounding tissue in rotation elastography, even in the absence of any inclusion-background modulus contrast.
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Affiliation(s)
- Basavarajappa Lokesh
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Anne M Ten Dam
- Medical Ultrasound Imaging Center (MUSIC 766), Radboud University Medical Center, Nijmegen, The Netherlands; Physics of Fluids Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Chris L de Korte
- Medical Ultrasound Imaging Center (MUSIC 766), Radboud University Medical Center, Nijmegen, The Netherlands; Physics of Fluids Group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Arun K Thittai
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India.
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Abstract
Liver stiffness is now a well-established noninvasive biomarker for assessing fibrosis in chronic liver disease. MRI-based and ultrasound-based dynamic elastography techniques have been introduced for assessment of liver stiffness and useful in clinical staging of hepatic fibrosis. Several different elastography techniques are now available with each method having inherent strengths and limitations. The published literature generally indicates that MR elastography has a higher diagnostic performance and fewer technical failures than ultrasound-based elastography techniques in assessing hepatic fibrosis. There is also significant potential to further develop elastography techniques to implement multiparametric methods that have promise for distinguishing between processes such as inflammation, fibrosis, venous congestion, and portal hypertension that can result in increased liver stiffness. In this commentary, we compare MR and ultrasound elastography methods and their utility in clinical practice.
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Yin Z, Sui Y, Trzasko JD, Rossman PJ, Manduca A, Ehman RL, Huston J. In vivo characterization of 3D skull and brain motion during dynamic head vibration using magnetic resonance elastography. Magn Reson Med 2018; 80:2573-2585. [PMID: 29774594 DOI: 10.1002/mrm.27347] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 04/08/2018] [Accepted: 04/13/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE To introduce newly developed MR elastography (MRE)-based dual-saturation imaging and dual-sensitivity motion encoding schemes to directly measure in vivo skull-brain motion, and to study the skull-brain coupling in volunteers with these approaches. METHODS Six volunteers were scanned with a high-performance compact 3T-MRI scanner. The skull-brain MRE images were obtained with a dual-saturation imaging where the skull and brain motion were acquired with fat- and water-suppression scans, respectively. A dual-sensitivity motion encoding scheme was applied to estimate the heavily wrapped phase in skull by the simultaneous acquisition of both low- and high-sensitivity phase during a single MRE exam. The low-sensitivity phase was used to guide unwrapping of the high-sensitivity phase. The amplitude and temporal phase delay of the rigid-body motion between the skull and brain was measured, and the skull-brain interface was visualized by slip interface imaging (SII). RESULTS Both skull and brain motion can be successfully acquired and unwrapped. The skull-brain motion analysis demonstrated the motion transmission from the skull to the brain is attenuated in amplitude and delayed. However, this attenuation (%) and delay (rad) were considerably greater with rotation (59 ± 7%, 0.68 ± 0.14 rad) than with translation (92 ± 5%, 0.04 ± 0.02 rad). With SII the skull-brain slip interface was not completely evident, and the slip pattern was spatially heterogeneous. CONCLUSION This study provides a framework for acquiring in vivo voxel-based skull and brain displacement using MRE that can be used to characterize the skull-brain coupling system for understanding of mechanical brain protection mechanisms, which has potential to facilitate risk management for future injury.
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Affiliation(s)
- Ziying Yin
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Yi Sui
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Joshua D Trzasko
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Phillip J Rossman
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Richard L Ehman
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - John Huston
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota
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Han G, Eriten M. Effect of relaxation-dependent adhesion on pre-sliding response of cartilage. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172051. [PMID: 29892390 PMCID: PMC5990745 DOI: 10.1098/rsos.172051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
Possible links between adhesive properties and the pre-sliding (static) friction response of cartilage are not fully understood in the literature. The aims of this study are to investigate the relation between adhesion and relaxation time in articular cartilage, and the effect of relaxation-dependent adhesion on the pre-sliding response of cartilage. Adhesion tests were performed to evaluate the work of adhesion of cartilage at different relaxation times. Friction tests were conducted to identify the pre-sliding friction response of cartilage at relaxation times corresponding to adhesion tests. The pre-sliding friction response of cartilage was systematically linked to the work of adhesion and contact conditions by a slip-based failure model. It was found that the work of adhesion increases with relaxation time. Also, the work of adhesion is linearly correlated to the resistance to slip-based failure. In addition, as the work of adhesion increases, the adhered (stick) area at the moment of failure increases, and the propagation rate of the annular slip (crack) area towards its centre increases. These findings offer a mechanistic explanation of the pre-sliding friction behaviour and stick-slip response of soft hydrated interfaces such as articular cartilage and hydrogels. In addition, the linear correlation between adhesion and threshold to slip-based failure enables estimation of the adhesive strength of such interfaces directly from the pre-sliding friction response (e.g. shear wave elastography).
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Affiliation(s)
- Guebum Han
- Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
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Kamal N, Reddy RK, Kohli G, Lee HJ, Ying YLM, Jyung RW, Liu JK. The Role of Fast Imaging Employing Steady-State Acquisition (FIESTA) Magnetic Resonance Imaging for Assessment of Delayed Enhancement of Fat Graft Packing on Postoperative Imaging After Vestibular Schwannoma Surgery. World Neurosurg 2018; 114:e1066-e1072. [PMID: 29605696 DOI: 10.1016/j.wneu.2018.03.147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 03/20/2018] [Accepted: 03/21/2018] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To investigate the role and efficacy of fast imaging employing steady-state acquisition (FIESTA) imaging in distinguishing fat graft enhancement from residual or recurrent tumor after vestibular schwannoma (VS) surgery. METHODS A retrospective study of 33 patients who underwent VS resection via the retrosigmoid or translabyrinthine approach with fat graft reconstruction was performed. Magnetic resonance imaging (MRI) was collected at different time points: preoperative, immediate postoperative (24-48 hours), delayed postoperative (3-6 months after surgery), and yearly postoperative. The image sets contained T1, T2, fat-suppressed T1-weighted with gadolinium, and FIESTA. The radiographs were analyzed for tumor recurrence by the primary neurosurgeon and an independent blinded neuroradiologist. If fat-suppressed T1-weighted images demonstrated postoperative enhancement in the resection bed, a comparison was made with FIESTA imaging. RESULTS At 3-6 months postoperatively and at 1 year and beyond, 28 (84.8%) and 33 (100%) of patients, respectively, displayed delayed enhancement of the fat graft on postgadolinium fat-suppressed T1-weighted MRI. The enhancement seen on postgadolinium, fat-suppressed, T1-weighted MRI consistently correlated with the characteristic fat graft signal on FIESTA imaging and not tumor recurrence. FIESTA imaging was able to distinguish residual tumor from enhancing fat graft compared with postgadolinium, fat-suppressed, T1-weighted MRI (P < 0.0001) due to distinctive signaling patterns. CONCLUSIONS FIESTA is an effective tool in discerning fat graft enhancement from residual or recurrent tumor on delayed postoperative imaging after VS resection. Fat graft used in reconstruction consistently enhances on delayed postoperative postgadolinium, fat-suppressed, T1-weighted imaging, which correlates with the fat graft signal seen on FIESTA images.
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Affiliation(s)
- Naveed Kamal
- Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Renuka K Reddy
- Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA; Department of Otolaryngology-Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Gurkirat Kohli
- Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Huey-Jen Lee
- Department of Radiology, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Yu-Lan Mary Ying
- Department of Otolaryngology-Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA; Center for Skull Base and Pituitary Surgery, Rutgers Neurological Institute of New Jersey, Newark, New Jersey, USA
| | - Robert W Jyung
- Department of Otolaryngology-Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA; Center for Skull Base and Pituitary Surgery, Rutgers Neurological Institute of New Jersey, Newark, New Jersey, USA
| | - James K Liu
- Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA; Department of Otolaryngology-Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA; Center for Skull Base and Pituitary Surgery, Rutgers Neurological Institute of New Jersey, Newark, New Jersey, USA.
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Hetzer S, Birr P, Fehlner A, Hirsch S, Dittmann F, Barnhill E, Braun J, Sack I. Perfusion alters stiffness of deep gray matter. J Cereb Blood Flow Metab 2018; 38:116-125. [PMID: 28151092 PMCID: PMC5757437 DOI: 10.1177/0271678x17691530] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Viscoelastic properties of the brain reflect tissue architecture at multiple length scales. However, little is known about the relation between vital tissue functions, such as perfusion, and the macroscopic mechanical properties of cerebral tissue. In this study, arterial spin labelling is paired with magnetic resonance elastography to investigate the relationship between tissue stiffness and cerebral blood flow (CBF) in the in vivo human brain. The viscoelastic modulus, | G*|, and CBF were studied in deep gray matter (DGM) of 14 healthy male volunteers in the following sub-regions: putamen, nucleus accumbens, hippocampus, thalamus, globus pallidus, and amygdala. CBF was further normalized by vessel area data to obtain the flux rate q which is proportional to the perfusion pressure gradient. The striatum (represented by putamen and nucleus accumbens) was distinct from the other DGM regions by displaying markedly higher stiffness and perfusion values. q was a predictive marker for DGM stiffness as analyzed by linear regression | G*| = q·(4.2 ± 0.6)kPa·s + (0.80 ± 0.06)kPa ( R2 = 0.92, P = 0.006). These results suggest a high sensitivity of MRE in DGM to perfusion pressure. The distinct mechano-vascular properties of striatum tissue, as compared to the rest of DGM, may reflect elevated perfusion pressure, which could explain the well-known susceptibility of the putamen to hemorrhages.
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Affiliation(s)
- Stefan Hetzer
- 1 Berlin Center for Advanced Neuroimaging, Charité - Universitätsmedizin Berlin, Berlin, Germany.,2 Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Patric Birr
- 3 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Andreas Fehlner
- 3 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Sebastian Hirsch
- 4 Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Florian Dittmann
- 3 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Eric Barnhill
- 3 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jürgen Braun
- 4 Institute of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ingolf Sack
- 3 Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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Murphy MC, Huston J, Ehman RL. MR elastography of the brain and its application in neurological diseases. Neuroimage 2017; 187:176-183. [PMID: 28993232 DOI: 10.1016/j.neuroimage.2017.10.008] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 12/13/2022] Open
Abstract
Magnetic resonance elastography (MRE) is an imaging technique for noninvasively and quantitatively assessing tissue stiffness, akin to palpation. MRE is further able assess the mechanical properties of tissues that cannot be reached by hand including the brain. The technique is a three-step process beginning with the introduction of shear waves into the tissue of interest by applying an external vibration. Next, the resulting motion is imaged using a phase-contrast MR pulse sequence with motion encoding gradients that are synchronized to the vibration. Finally, the measured displacement images are mathematically inverted to compute a map of the estimated stiffness. In the brain, the technique has demonstrated strong test-retest repeatability with typical errors of 1% for measuring global stiffness, 2% for measuring stiffness in the lobes of the brain, and 3-7% for measuring stiffness in subcortical gray matter. In healthy volunteers, multiple studies have confirmed that stiffness decreases with age, while more recent studies have demonstrated a strong relationship between viscoelasticity and behavioral performance. Furthermore, several studies have demonstrated the sensitivity of brain stiffness to neurodegeneration, as stiffness has been shown to decrease in multiple sclerosis and in several forms of dementia. Moreover, the spatial pattern of stiffness changes varies among these different classes of dementia. Finally, MRE is a promising tool for the preoperative assessment of intracranial tumors, as it can measure both tumor consistency and adherence to surrounding tissues. These factors are important predictors of surgical difficulty. In brief, MRE demonstrates potential value in a number of neurological diseases. However, significant opportunity remains to further refine the technique and better understand the underlying physiology.
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Affiliation(s)
- Matthew C Murphy
- Department of Radiology, Mayo Clinic, Rochester, MN, United States.
| | - John Huston
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
| | - Richard L Ehman
- Department of Radiology, Mayo Clinic, Rochester, MN, United States
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Rai SKR, Mancarella C, Goel AH. Brain Tumor Interface Dissection Technique with Surgical Blade from Laboratory to Neurosurgical Operating Room. World Neurosurg 2017; 100:601-606. [DOI: 10.1016/j.wneu.2017.01.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 01/12/2017] [Accepted: 01/16/2017] [Indexed: 11/27/2022]
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Kennedy P, Macgregor LJ, Barnhill E, Johnson CL, Perrins M, Hunter A, Brown C, van Beek EJR, Roberts N. MR elastography measurement of the effect of passive warmup prior to eccentric exercise on thigh muscle mechanical properties. J Magn Reson Imaging 2017; 46:1115-1127. [PMID: 28218814 PMCID: PMC5600114 DOI: 10.1002/jmri.25642] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/06/2017] [Indexed: 01/19/2023] Open
Abstract
Purpose To investigate the effect of warmup by application of the thermal agent Deep Heat (DH) on muscle mechanical properties using magnetic resonance elastography (MRE) at 3T before and after exercise‐induced muscle damage (EIMD). Materials and Methods Twenty male participants performed an individualized protocol designed to induce EIMD in the quadriceps. DH was applied to the thigh in 50% of the participants before exercise. MRE, T2‐weighted MRI, maximal voluntary contraction (MVC), creatine kinase (CK) concentration, and muscle soreness were measured before and after the protocol to assess EIMD effects. Five participants were excluded: four having not experienced EIMD and one due to incidental findings. Results Total workload performed during the EIMD protocol was greater in the DH group than the control group (P < 0.03), despite no significant differences in baseline MVC (P = 0.23). Shear stiffness |G*| increased in the rectus femoris (RF) muscle in both groups (P < 0.03); however, DH was not a significant between‐group factor (P = 0.15). MVC values returned to baseline faster in the DH group (5 days) than the control group (7 days). Participants who displayed hyperintensity on T2‐weighted images had a greater stiffness increase following damage than those without: RF; 0.61 kPa vs. 0.15 kPa, P < 0.006, vastus intermedius; 0.34 kPa vs. 0.03 kPa, P = 0.06. Conclusion EIMD produces increased muscle stiffness as measured by MRE, with the change in |G*| significantly increased when T2 hyperintensity was present. DH did not affect CK concentration or soreness; however, DH participants produced greater workload during the EIMD protocol and exhibited accelerated MVC recovery. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1115–1127.
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Affiliation(s)
- Paul Kennedy
- Clinical Research Imaging Centre (CRIC), Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK.,Translational and Molecular Imaging Institute (TMII), Icahn School of Medicine at Mount Sinai, New York, USA
| | - Lewis J Macgregor
- Health and Exercise Research Group, School of Sport, University of Stirling, UK
| | - Eric Barnhill
- Department of Radiological Science, Charité-Universitätsmedizin, Berlin, Germany
| | - Curtis L Johnson
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Michael Perrins
- Clinical Research Imaging Centre (CRIC), Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Angus Hunter
- Health and Exercise Research Group, School of Sport, University of Stirling, UK
| | - Colin Brown
- The Mentholatum Company Ltd, East Kilbride, Glasgow, UK
| | - Edwin J R van Beek
- Clinical Research Imaging Centre (CRIC), Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Neil Roberts
- Clinical Research Imaging Centre (CRIC), Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
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Yin Z, Hughes JD, Trzasko JD, Glaser KJ, Manduca A, Van Gompel J, Link MJ, Romano A, Ehman RL, Huston J. Slip interface imaging based on MR-elastography preoperatively predicts meningioma-brain adhesion. J Magn Reson Imaging 2017; 46:1007-1016. [PMID: 28194925 PMCID: PMC5600107 DOI: 10.1002/jmri.25623] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/16/2016] [Accepted: 12/18/2016] [Indexed: 01/26/2023] Open
Abstract
Purpose To investigate the ability of slip interface imaging (SII), a recently developed magnetic resonance elastography (MRE)‐based technique, to predict the degree of meningioma–brain adhesion, using findings at surgery as the reference standard. Materials and Methods With Institutional Review Board approval and written informed consent, 25 patients with meningiomas >2.5 cm in maximal diameter underwent preoperative SII assessment. Intracranial shear motions were introduced using a soft, pillow‐like head driver and the resulting displacement field was acquired with an MRE pulse sequence on 3T MR scanners. The displacement data were analyzed to determine tumor–brain adhesion by assessing intensities on shear line images and raw as well as normalized octahedral shear strain (OSS) values along the interface. The SII findings of shear line images, OSS, and normalized OSS were independently and blindly correlated with surgical findings of tumor adhesion by using the Cohen's κ coefficient and chi‐squared test. Results Neurosurgeons categorized the surgical plane as extrapial (no adhesion) in 15 patients, mixed in four, and subpial (adhesion) in six. Both shear line images and OSS agreed with the surgical findings in 18 (72%) cases (fair agreement, κ = 0.37, 95% confidence interval [CI]: 0.05–0.69), while normalized OSS was concordant with the surgical findings in 23 (92%) cases (good agreement, κ = 0.86, 95% CI: 0.67–1). The correlation between SII predictions (shear line images, OSS, and normalized OSS) and the surgical findings were statistically significant (chi‐squared test, P = 0.02, P = 0.02, and P < 0.0001, respectively). Conclusion SII preoperatively evaluates the degree of meningioma–brain adhesion noninvasively, allowing for improved prediction of surgical risk and tumor resectability. Level of Evidence: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1007–1016.
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Affiliation(s)
- Ziying Yin
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Joshua D Hughes
- Department of Neurosurgery, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Joshua D Trzasko
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Kevin J Glaser
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Armando Manduca
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Jamie Van Gompel
- Department of Neurosurgery, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Michael J Link
- Department of Neurosurgery, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Anthony Romano
- Naval Research Laboratory, Code 7160, Washington, DC, USA
| | - Richard L Ehman
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - John Huston
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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Marupudi NI, Altinok D, Goncalves L, Ham SD, Sood S. Apparent diffusion coefficient mapping in medulloblastoma predicts non-infiltrative surgical planes. Childs Nerv Syst 2016; 32:2183-2187. [PMID: 27406557 DOI: 10.1007/s00381-016-3168-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/04/2016] [Indexed: 11/30/2022]
Abstract
INTRODUCTION An appropriate surgical approach for posterior fossa lesions is to start tumor removal from areas with a defined plane to where tumor is infiltrating the brainstem or peduncles. This surgical approach minimizes risk of damage to eloquent areas. Although magnetic resonance imaging (MRI) is the current standard preoperative imaging obtained for diagnosis and surgical planning of pediatric posterior fossa tumors, it offers limited information on the infiltrative planes between tumor and normal structures in patients with medulloblastomas. Because medulloblastomas demonstrate diffusion restriction on apparent diffusion coefficient map (ADC map) sequences, we investigated the role of ADC map in predicting infiltrative and non-infiltrative planes along the brain stem and/or cerebellar peduncles by medulloblastomas prior to surgery. METHODS Thirty-four pediatric patients with pathologically confirmed medulloblastomas underwent surgical resection at our facility from 2004 to 2012. An experienced pediatric neuroradiologist reviewed the brain MRIs/ADC map, assessing the planes between the tumor and cerebellar peduncles/brain stem. An independent evaluator documented surgical findings from operative reports for comparison to the radiographic findings. The radiographic findings were statistically compared to the documented intraoperative findings to determine predictive value of the test in identifying tumor infiltration of the brain stem cerebellar peduncles. RESULTS Twenty-six patients had preoperative ADC mapping completed and thereby, met inclusion criteria. Mean age at time of surgery was 8.3 ± 4.6 years. Positive predictive value of ADC maps to predict tumor invasion of the brain stem and cerebellar peduncles ranged from 69 to 88 %; negative predictive values ranged from 70 to 89 %. Sensitivity approached 93 % while specificity approached 78 %. CONCLUSIONS ADC maps are valuable in predicting the infiltrative and non-infiltrative planes along the tumor and brain stem interface in medulloblastomas. Inclusion and evaluation of ADC maps in preoperative evaluation can assist in surgical resection planning in patients with medulloblastoma.
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Affiliation(s)
- Neena I Marupudi
- Department of Neurosurgery, Wayne State University, Children's Hospital of Michigan, Detroit, MI, USA
| | - Deniz Altinok
- Department of Pediatric Radiology, Wayne State University, Children's Hospital of Michigan, Detroit, MI, USA
| | - Luis Goncalves
- Department of Pediatric Radiology, Wayne State University, Children's Hospital of Michigan, Detroit, MI, USA
| | - Steven D Ham
- Department of Neurosurgery, Wayne State University, Children's Hospital of Michigan, Detroit, MI, USA
| | - Sandeep Sood
- Department of Neurosurgery, Wayne State University, Children's Hospital of Michigan, Detroit, MI, USA.
- Pediatric Neurosurgery, Children's Hospital of Michigan, 3901 Beaubien St., 2nd Floor, Detroit, MI, 48201, USA.
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Fehlner A, Hirsch S, Weygandt M, Christophel T, Barnhill E, Kadobianskyi M, Braun J, Bernarding J, Lützkendorf R, Sack I, Hetzer S. Increasing the spatial resolution and sensitivity of magnetic resonance elastography by correcting for subject motion and susceptibility-induced image distortions. J Magn Reson Imaging 2016; 46:134-141. [DOI: 10.1002/jmri.25516] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 10/05/2016] [Indexed: 12/13/2022] Open
Affiliation(s)
- Andreas Fehlner
- Department of Radiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Sebastian Hirsch
- Institute of Medical Informatics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Martin Weygandt
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
| | - Thomas Christophel
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
| | - Eric Barnhill
- Department of Radiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Mykola Kadobianskyi
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
| | - Jürgen Braun
- Institute of Medical Informatics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Johannes Bernarding
- Institute of Biometry and Medical Informatics; Otto-von-Guericke University; Magdeburg Germany
| | - Ralf Lützkendorf
- Institute of Biometry and Medical Informatics; Otto-von-Guericke University; Magdeburg Germany
| | - Ingolf Sack
- Department of Radiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Stefan Hetzer
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
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Kofahl AL, Theilenberg S, Bindl J, Ulucay D, Wild J, Napiletzki S, Schu-Schätter B, Vohlen A, Pintea B, Finsterbusch J, Hattingen E, Urbach C, Maier K. Combining rheology and MRI: Imaging healthy and tumorous brains based on mechanical properties. Magn Reson Med 2016; 78:930-940. [PMID: 27699841 DOI: 10.1002/mrm.26477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 08/22/2016] [Accepted: 09/01/2016] [Indexed: 11/10/2022]
Abstract
PURPOSE It is well known that pathological changes in tissue alter its mechanical properties. This holds also true for brain tissue. In case of the brain, however, obtaining information about these properties is hard due to the surrounding cranial bone. In this paper a novel technique to create an imaging contrast based on the aforementioned properties is presented. METHODS The method is based on an excitation of the brain induced by a short fall. The response of the brain tissue is measured using a motion sensitive MRI sequence. RESULTS The new method is tested by measurements on phantom material as well as on healthy volunteers. In a proof of principle experiment the capability of the approach to identify local alterations in the mechanical properties is shown by means of measurements on meningioma patients. CONCLUSION The presented results show the feasibility of the novel method. Even in this early state of the proposed method, comparisons of measurements on meningioma patients with intraoperative palpation suggest that meningioma tissue responds differently to the excitation depending on their mechanical properties. Magn Reson Med 78:930-940, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Anna-Lisa Kofahl
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | | | - Jakob Bindl
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Deniz Ulucay
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Judith Wild
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Sylvia Napiletzki
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Birgit Schu-Schätter
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Alexandra Vohlen
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Bogdan Pintea
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Jürgen Finsterbusch
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Elke Hattingen
- Department of Neuroradiology, University Hospital Bonn, Bonn, Germany
| | - Carsten Urbach
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
| | - Karl Maier
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Bonn, Germany
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