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Wada H, Shimauchi-Ohtaki H, Tosaka M, Kawashima T, Osawa T, Osawa S, Horiguchi K, Nakata S, Yoshimoto Y. Comparison of Early Postoperative Diffusion Weighted Magnetic Resonance Imaging Findings After Resection of Gliomas and Meningiomas. World Neurosurg 2024:S1878-8750(24)00512-6. [PMID: 38548056 DOI: 10.1016/j.wneu.2024.03.126] [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: 03/18/2024] [Accepted: 03/21/2024] [Indexed: 04/21/2024]
Abstract
OBJECTIVE Glioma and meningioma require vastly different surgical approaches, even if only involving a simple craniotomy procedure. Diffusion weighted imaging (DWI) is useful for the postoperative evaluation of ischemic damage. The present study evaluated the expected but unproven differences in DWI findings. METHODS A total of 41 patients with meningiomas and 63 with gliomas met the inclusion criteria for adult cases with superficial lesions treated through simple supratentorial craniotomy. Postoperative DWI findings of DWI-positive rate, DWI-positive area type, and relationship with neurological deficits were evaluated. RESULTS The DWI-positive rate (P = 0.01) and the proportion of rim-type lesions (P < 0.01) were significantly more common in gliomas. Patients with meningiomas and DWI-positive areas presented with higher rates of new neurological deficits (P < 0.01), and patients with meningiomas on the left side were more likely to develop new neurological deficits (P = 0.02). Patients with gliomas tended to develop new deficits with larger DWI-positive area volumes (P = 0.04). CONCLUSIONS Postoperative early DWI-positive rate and rim-type lesions are more common after glioma resection than meningioma resection. Larger volumes of DWI-positive areas may be associated with postoperative neurological symptoms in gliomas. DWI-positive finding is less common after meningioma than glioma resection but more likely to be associated with new neurological symptoms. These differences are important for adequate postoperative DWI evaluation of common supratentorial brain tumors.
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Affiliation(s)
- Hajime Wada
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Hiroya Shimauchi-Ohtaki
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
| | - Masahiko Tosaka
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Takahiro Kawashima
- Department of Neurosurgery, Tatebayashi Kosei General Hospital, Tatebayashi, Gunma, Japan
| | - Tadashi Osawa
- Department of Neurosurgery, Hidaka Hospital, Takasaki, Gunma, Japan
| | - Sho Osawa
- Department of Neurosurgery and Neuro-Oncology, National Cancer Center Hospital, Chuo-Ku, Tokyo, Japan
| | - Keishi Horiguchi
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Satoshi Nakata
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yuhei Yoshimoto
- Department of Neurosurgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
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Smith HJ. The history of magnetic resonance imaging and its reflections in Acta Radiologica. Acta Radiol 2021; 62:1481-1498. [PMID: 34657480 DOI: 10.1177/02841851211050857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The first reports in Acta Radiologica on magnetic resonance imaging (MRI) were published in 1984, four years after the first commercial MR scanners became available. For the first two years, all MR papers originated from the USA. Nordic contributions started in 1986, and until 2020, authors from 44 different countries have published MR papers in Acta Radiologica. Papers on MRI have constituted, on average, 30%-40% of all published original articles in Acta Radiologica, with a high of 49% in 2019. The MR papers published since 1984 document tremendous progress in several areas such as magnet and coil design, motion compensation techniques, faster image acquisitions, new image contrast, contrast-enhanced MRI, functional MRI, and image analysis. In this historical review, all of these aspects of MRI are discussed and related to Acta Radiologica papers.
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Affiliation(s)
- Hans-Jørgen Smith
- Department of Radiology and Nuclear Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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Geijer M, Thomsen HS. Change and consistency in Acta Radiologica over 100 years. Acta Radiol 2021; 62:1435-1442. [PMID: 34678081 PMCID: PMC8649460 DOI: 10.1177/02841851211054174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 11/15/2022]
Abstract
Acta Radiologica celebrates its 100th anniversary in 2021. In this article, the foundation of the journal and its editors are described. During 100 years, the manuscript structure changed from single-author verbose monographs to multi-author collaborations on statistically analyzed research subjects. The authorship changed from purely Nordic authors to a truly international cadre of authors, and the size of the journal increased considerably, in issues per year, printed pages, and published articles per year. The Foundation of Acta Radiologica has been able to give out two prizes, the Xenia Forsselliana and the Acta Radiologica International Scientific Prize for the best manuscripts each year. The increasing submissions of manuscripts is an indication that Acta Radiologica will continue to publish important scientific results for many years to come.
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Affiliation(s)
- Mats Geijer
- Department of Radiology, Institute of Clinical Sciences, 70712Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Radiology, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Henrik S Thomsen
- University of Copenhagen, Copenhagen University Hospital, Herlev & Gentofte, Herlev, Denmark
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Wáng YXJ. A reduction of perfusion can lead to an artificial elevation of slow diffusion measure: examples in acute brain ischemia MRI intravoxel incoherent motion studies. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:895. [PMID: 34164529 PMCID: PMC8184460 DOI: 10.21037/atm-21-1468] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Yì Xiáng J Wáng
- Department of Imaging and Interventional Radiology, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Hong Kong, China
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Magill ST, Nguyen MP, Aghi MK, Theodosopoulos PV, Villanueva-Meyer JE, McDermott MW. Postoperative diffusion-weighted imaging and neurological outcome after convexity meningioma resection. J Neurosurg 2021; 135:1008-1015. [PMID: 33513570 DOI: 10.3171/2020.8.jns193537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 08/10/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Convexity meningiomas are commonly managed with resection. Motor outcomes and predictors of new deficits after surgery are poorly studied. The objective of this study was to determine whether postoperative diffusion-weighted imaging (DWI) was associated with neurological deficits after convexity meningioma resection and to identify the risk factors for postoperative DWI restriction. METHODS A retrospective review of patients who had undergone convexity meningioma resection from 2014 to 2018 was performed. Univariate and multivariate logistic regressions were performed to identify variables associated with postoperative neurological deficits and a DWI signal. The amount of postoperative DWI signal was measured and was correlated with low apparent diffusion coefficient maps to confirm ischemic injury. RESULTS The authors identified 122 patients who had undergone a total of 125 operations for convexity meningiomas. The median age at surgery was 57 years, and 70% of the patients were female. The median follow-up was 26 months. The WHO grade was I in 62% of cases, II in 36%, and III in 2%. The most common preoperative deficits were seizures (24%), extremity weakness/paralysis (16%), cognitive/language/memory impairment (16%), and focal neurological deficit (16%). Following resection, 89% of cases had no residual deficit. Postoperative DWI showed punctate or no diffusion restriction in 78% of cases and restriction > 1 cm in 22% of cases. An immediate postoperative neurological deficit was present in 14 patients (11%), but only 8 patients (7%) had a deficit at 3 months postoperatively. Univariate analysis identified DWI signal > 1 cm (p < 0.0001), tumor diameter (p < 0.0001), preoperative motor deficit (p = 0.0043), older age (p = 0.0113), and preoperative embolization (p = 0.0171) as risk factors for an immediate postoperative deficit, whereas DWI signal > 1 cm (p < 0.0001), tumor size (p < 0.0001), and older age (p = 0.0181) were risk factors for deficits lasting more than 3 months postoperatively. Multivariate analysis revealed a DWI signal > 1 cm to be the only significant risk factor for deficits at 3 months postoperatively (OR 32.42, 95% CI 3.3-320.1, p = 0.0002). Further, estimated blood loss (OR 1.4 per 100 ml increase, 95% CI 1.1-1.7, p < 0.0001), older age (OR 1.1 per year older, 95% CI 1.0-1.1, p = 0.0009), middle third location in the sagittal plane (OR 16.9, 95% CI 1.3-216.9, p = 0.0026), and preoperative peritumoral edema (OR 4.6, 95% CI 1.2-17.7, p = 0.0249) were significantly associated with a postoperative DWI signal > 1 cm. CONCLUSIONS A DWI signal > 1 cm is significantly associated with postoperative neurological deficits, both immediate and long-lasting. Greater estimated blood loss, older age, tumor location over the motor strip, and preoperative peritumoral edema increase the risk of having a postoperative DWI signal > 1 cm, reflective of perilesional ischemia. Most immediate postoperative deficits will improve over time. These data are valuable when preoperatively communicating with patients about the risks of surgery and when postoperatively discussing prognosis after a deficit occurs.
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Raman MR, Kantarci K, Murray ME, Jack CR, Vemuri P. Imaging markers of cerebrovascular pathologies: Pathophysiology, clinical presentation, and risk factors. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2016; 5:5-14. [PMID: 28054023 PMCID: PMC5198884 DOI: 10.1016/j.dadm.2016.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cerebrovascular pathologies (CVPs) are common pathologies associated with age-related cognitive decline along with Alzheimer disease pathologies. The impact of CVP on the prevalence of dementia is increasingly being recognized. The goal of this review is to improve our understanding of the pathophysiological underpinnings and the multimodal magnetic resonance imaging and positron emission tomography imaging changes that are associated with the hallmarks of CVP. This knowledge will facilitate the development of early detection, intervention, and prevention strategies that may contribute to lowering the risk of dementia. In this review, we will first discuss currently known risk factors of CVPs including cardiovascular, lifestyle, genetic, sex differences, and head injury. Next, we will focus on the pathophysiology of CVPs and their impact on neurodegeneration and downstream cognitive impairment. Specifically, we will discuss three of the most common cerebrovascular lesions seen on MRI: white-matter hyperintensity, microbleeds, and infarcts. Finally, we will discuss the unanswered open questions in this field.
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Affiliation(s)
| | - Kejal Kantarci
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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Huang HM, Shih YY, Lin C. Formation of parametric images using mixed-effects models: a feasibility study. NMR IN BIOMEDICINE 2016; 29:239-247. [PMID: 26915793 DOI: 10.1002/nbm.3453] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/18/2015] [Accepted: 11/08/2015] [Indexed: 06/05/2023]
Abstract
Mixed-effects models have been widely used in the analysis of longitudinal data. By presenting the parameters as a combination of fixed effects and random effects, mixed-effects models incorporating both within- and between-subject variations are capable of improving parameter estimation. In this work, we demonstrate the feasibility of using a non-linear mixed-effects (NLME) approach for generating parametric images from medical imaging data of a single study. By assuming that all voxels in the image are independent, we used simulation and animal data to evaluate whether NLME can improve the voxel-wise parameter estimation. For testing purposes, intravoxel incoherent motion (IVIM) diffusion parameters including perfusion fraction, pseudo-diffusion coefficient and true diffusion coefficient were estimated using diffusion-weighted MR images and NLME through fitting the IVIM model. The conventional method of non-linear least squares (NLLS) was used as the standard approach for comparison of the resulted parametric images. In the simulated data, NLME provides more accurate and precise estimates of diffusion parameters compared with NLLS. Similarly, we found that NLME has the ability to improve the signal-to-noise ratio of parametric images obtained from rat brain data. These data have shown that it is feasible to apply NLME in parametric image generation, and the parametric image quality can be accordingly improved with the use of NLME. With the flexibility to be adapted to other models or modalities, NLME may become a useful tool to improve the parametric image quality in the future. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Husan-Ming Huang
- Medical Physics Research Center, Institute of Radiological Research, Chang Gung University and Chang Gung Memorial Hospital, Taoyuan City, Taiwan (ROC)
| | - Yi-Yu Shih
- Siemens Shenzhen Magnetic Resonance Ltd., Siemens MR Center, Shenzhen, People's Republic of China
| | - Chieh Lin
- Department of Nuclear Medicine, Linkou Chang Gung Memorial Hospital, Taoyuan City, Taiwan (ROC)
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Deveci OS, Celik AI, Ikikardes F, Ozmen C, Caglıyan CE, Deniz A, Bicakci K, Bicakci S, Evlice A, Demir T, Kanadasi M, Demir M, Demirtas M. The Incidence and the Risk Factors of Silent Embolic Cerebral Infarction After Coronary Angiography and Percutaneous Coronary Interventions. Angiology 2015; 67:433-7. [PMID: 26253467 DOI: 10.1177/0003319715599281] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Silent embolic cerebral infarction (SECI) is a major complication of coronary angiography (CAG) and percutaneous coronary intervention (PCI). Patients with stable coronary artery disease (CAD) who underwent CAG with or without PCI were recruited. Cerebral diffusion-weighted magnetic resonance imaging was performed for SECI within 24 hours. Clinical and angiographic characteristics were compared between patients with and without SECI. Silent embolic cerebral infarction occurred in 12 (12%) of the 101 patients. Age, total cholesterol, SYNTAX score (SS), and coronary artery bypass history were greater in the SECI(+) group (65 ± 10 vs 58 ± 11 years,P= .037; 223 ± 85 vs 173 ± 80 mg/dL,P= .048; 30.1 ± 2 vs 15 ± 3,P< .001; 4 [33.3%] vs 3 [3.3%],P= .005). The SECI was more common in the PCI group (8/24 vs 4/77,P= .01). On subanalysis, the SS was significantly higher in the SECI(+) patients in both the CAG and the PCI groups (29.3 ± 1.9 vs 15 ± 3,P< .01; 30.5 ± 1.9 vs 15.1 ± 3.2,P< .001, respectively). The risk of SECI after CAG and PCI increases with the complexity of CAD (represented by the SS). The SS is a predictor of the risk of SECI, a complication that should be considered more often after CAG.
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Affiliation(s)
- Onur Sinan Deveci
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Aziz Inan Celik
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Firat Ikikardes
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Caglar Ozmen
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Caglar Emre Caglıyan
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Ali Deniz
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Kenan Bicakci
- Faculty of Medicine, Department of Radiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Sebnem Bicakci
- Faculty of Medicine, Department of Neurology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Ahmet Evlice
- Faculty of Medicine, Department of Neurology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Turgay Demir
- Faculty of Medicine, Department of Neurology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Mehmet Kanadasi
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Mesut Demir
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
| | - Mustafa Demirtas
- Faculty of Medicine, Department of Cardiology, Cukurova University, Balcali Hospital, Adana, Turkey
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Lee H, Cohen OS, Rosenmann H, Hoffmann C, Kingsley PB, Korczyn AD, Chapman J, Prohovnik I. Cerebral white matter disruption in Creutzfeldt-Jakob disease. AJNR Am J Neuroradiol 2012; 33:1945-50. [PMID: 22576896 DOI: 10.3174/ajnr.a3125] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Human prion diseases are known to cause gray matter degeneration in specific cerebral structures, but evidence for white matter involvement is scarce. We used DTI to test the hypothesis that white matter integrity is disrupted in human CJD during the early stages of the disease. MATERIALS AND METHODS Twenty-one patients with the E200K variant of CJD and 19 controls participated in DTI studies conducted on a 1.5T MR imaging scanner. The data were quantitatively analyzed and mapped with a voxelwise TBSS method. RESULTS We found significant reductions of FA in patients with CJD in distinct and functionally relevant white matter pathways, including the corticospinal tract, internal capsule, external capsule, fornix, and posterior thalamic radiation. Moreover, these FA deficits increased with disease duration, and were mainly determined by increase of radial diffusivity, suggesting elevated permeability of axonal membranes. CONCLUSIONS The findings suggest that some of the symptoms of CJD may be caused by a functional dysconnection syndrome, and that the leukoencephalopathy is progressive and detectable fairly early in the course of the disease.
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Affiliation(s)
- H Lee
- Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA
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10
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Li TQ, Wahlund LO. The search for neuroimaging biomarkers of Alzheimer's disease with advanced MRI techniques. Acta Radiol 2011; 52:211-22. [PMID: 21498351 DOI: 10.1258/ar.2010.100053] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The aim of this review is to examine the recent literature on using advanced magnetic resonance imaging (MRI) techniques for finding neuroimaging biomarkers that are sensitive to the detection of risks for Alzheimer's disease (AD). Since structural MRI techniques, such as brain structural volumetry and voxel-based morphometry (VBM), have been widely used for AD studies and extensively reviewed, we will only briefly touch on the topics of volumetry and morphometry. The focus of the current review is about the more recent developments in the search for AD neuroimaging biomarkers with functional MRI (fMRI), resting-state functional connectivity MRI (fcMRI), diffusion tensor imaging (DTI), arterial spin-labeling (ASL), and magnetic resonance spectroscopy (MRS).
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Affiliation(s)
- Tie-Qiang Li
- Karolinska Huddinge – Medical Physics, Stockholm
| | - Lars-Olof Wahlund
- Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden
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Robertson RL, Glasier CM. Diffusion-weighted imaging of the brain in infants and children. Pediatr Radiol 2007; 37:749-68. [PMID: 17589837 DOI: 10.1007/s00247-007-0515-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 03/30/2007] [Accepted: 04/27/2007] [Indexed: 01/12/2023]
Abstract
During the last decade, diffusion-weighted imaging (DWI) has become an important tool in the evaluation of a variety of disorders of the central nervous system in children. DWI relies on variability in the diffusivity of water molecules in the presence of a supplemental diffusion-sensitizing gradient to produce image contrast. Pathologic states alter the diffusion characteristics of brain water in a reproducible fashion. In this review, the DWI appearances of a number of common abnormalities of the brain in infants and children are presented.
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Affiliation(s)
- Richard L Robertson
- Department of Radiology, Main 2, Children's Hospital Boston, 300 Longwood Ave., Boston, MA 02115, USA.
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12
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Reiche W, Hagen T, Schuchardt V, Billmann P. Diffusion-weighted MR imaging improves diagnosis of CNS lymphomas. Clin Neurol Neurosurg 2007; 109:92-101. [PMID: 16644103 DOI: 10.1016/j.clineuro.2006.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2005] [Revised: 03/13/2006] [Accepted: 03/15/2006] [Indexed: 10/24/2022]
Abstract
The frequency of CNS lymphomas is increasing in immunocompetent as well as in immunocompromised patients and its incidence accounts for approximately 1-2% of all primary cerebral neoplasms. It is a challenge to recognize CNS lymphomas by MR imaging as early as possible in order to dispose an optimal therapy. The aim of this report is to demonstrate, how diffusion-weighted MR imaging improves the accuracy of the differential diagnosis of CNS lymphomas.
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Affiliation(s)
- Werner Reiche
- Institute of Radiology, Lahr-Ettenheim Clinical Center, 77933 Lahr, Germany.
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13
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Gregory DG, Pelak VS, Bennett JL. Diffusion-weighted magnetic resonance imaging and the evaluation of cortical blindness in preeclampsia. Surv Ophthalmol 2003; 48:647-50. [PMID: 14609710 DOI: 10.1016/j.survophthal.2003.08.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cortical blindness is an uncommon, but dramatic, complication of preeclampsia. We present a case in which diffusion-weighted magnetic resonance imaging played a critical role in determining the etiology of the cortical blindness and its subsequent management.
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Affiliation(s)
- Darren G Gregory
- Department of Ophthalmology, Rocky Mountain Lions Eye Institute, University of Colorado Health Sciences Center, Denver, Colorado, USA
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Abstract
The ability of the adult brain to form new connections in areas denervated by a lesion (axonal sprouting) is more widespread than previously thought, but mechanisms remain unknown. We have previously demonstrated an unexpected, robust axonal sprouting of contralateral corticostriatal neurons into the denervated striatum after ischemic cortical lesions. We now take advantage of marked differences in the degree of axonal sprouting from contralateral homotypic cortex after two types of cortical lesions to define the role of neuronal activity in this response. Thermal-ischemic lesions (TCL) of sensorimotor cortex, which induce axonal sprouting, produced two sequential patterns of low-frequency, synchronized neuronal activity that are not seen after similarly sized aspiration lesions, which do not induce axonal sprouting. An early rhythm of synchronous neuronal activity occurred in perilesion cortex on day 1 after lesion, with a frequency range of 0.2-2 Hz. A later pattern of activity occurred on days 2 and 3 after lesion, with a frequency range of 0.1-0.4 Hz. This second rhythm synchronized neuronal activity across widespread areas, including the cortical areas that contain the cell bodies of the sprouting axons. TTX was used to block this patterned neuronal activity and determine whether axonal sprouting was prevented. Chronic TTX infusion into the lesion site blocked the synchronous neuronal activity after TCL as well as axonal sprouting. Thus, both after different types of lesions and in the blockade experiments axonal sprouting was strongly correlated with synchronous neuronal activity, suggesting a role for this activity in anatomical reorganization after brain lesion in the adult.
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15
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Adami A, Thijs V, Tong DC, Beaulieu C, Moseley ME, Yenari MA. Use of diffusion weighted MRI to predict the occurrence and severity of hemorrhagic transformation in a rabbit model of embolic stroke. Brain Res 2002; 944:32-9. [PMID: 12106663 DOI: 10.1016/s0006-8993(02)02704-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Severe hemorrhagic transformation (HT) is an important complication of thrombolytic therapy. A method to identify stroke victims destined to severe HT could improve the patient selection and thus the safety of such treatment. In this study, we investigated whether very early serial diffusion weighted magnetic resonance imaging (DWI) could predict the occurrence of HT in an embolic model of experimental stroke. We tested the hypothesis that the ischemic brains with very low initial apparent diffusion coefficients (ADC) are destined to severe early (<or=5.5 h) HT. We retrospectively analyzed DWI scans of 45 New Zealand white rabbits subjected to thromboembolic stroke and treated with thrombolysis. DWI was obtained 0.5, 2, 3 and 5 h after embolization. Various thrombolytics were administered 1 h post embolization. The percentage of pixels within the ischemic hemisphere with ADC values below 550 x 10(-6) mm(2)/s was calculated and then compared to the severity of HT observed on gross brain sections at 5.5 h. As early as 30 min after embolization, ischemic brains destined to severe HT exhibited a significantly greater percentage of pixels below the cut-off value compared to those without HT: severe HT: 25%, 18.75-37.25% vs. no HT: 12%, 5.00-16.00% (median, 25th-75th %, P<0.001). Petechial HT when percentages were in the intermediate range. Quantitative analysis of initial ADC value might identify individual stroke patients at risk of severe HT.
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Affiliation(s)
- Alessandro Adami
- Department of Neurology and Neurological Sciences, Stanford University, CA 94305-5487, USA
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Chen ZG, Li TQ, Hindmarsh T. Diffusion tensor trace mapping in normal adult brain using single-shot EPI technique. A methodological study of the aging brain. Acta Radiol 2001. [PMID: 11552881 DOI: 10.1034/j.1600-0455.2001.420504.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To quantify age-related changes of the average diffusion coefficient value in normal adult brain using orientation-independent diffusion tensor trace mapping and to address the methodological influences on diffusion quantification. MATERIAL AND METHODS Fifty-four normal subjects (aged 20-79 years) were studied on a 1.5-T whole-body MR medical unit using a diffusion-weighted single-shot echo-planar imaging technique. Orientation-independent diffusion tensor trace maps were constructed for each subject using diffusion-weighted MR measurements in four different directions using a tetrahedral gradient combination pattern. The global average (including cerebral spinal fluid) and the tissue average of diffusion coefficients in adult brains were determined by analyzing the diffusion coefficient distribution histogram for the entire brain. Methodological influences on the measured diffusion coefficient were also investigated by comparing the results obtained using different experimental settings. RESULTS Both global and tissue averages of the diffusion coefficient are significantly correlated with age (p<0.03). The global average of the diffusion coefficient increases 3% per decade after the age of 40, whereas the increase in the tissue average of diffusion coefficient is about 1% per decade. Experimental settings for self-diffusion measurements, such as data acquisition methods and number of b-values, can slightly influence the statistical distribution histogram of the diffusion tensor trace and its average value. CONCLUSION Increased average diffusion coefficient in adult brains with aging are consistent with findings regarding structural changes in the brain that have been associated with aging. The study also demonstrates that it is desirable to use the same experimental parameters for diffusion coefficient quantification when comparing between different subjects and groups of interest.
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Affiliation(s)
- Z G Chen
- Karolinska MR Research Center, Department of Neuroradiology, Karolinska Hospital, Stockholm, Sweden
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Abstract
Concussed athletes may have documented incapacitating postconcussive symptoms, neuropsychological deficits, and consequent important changes in their lives and sport, yet the majority of neuroimaging attempts reveal few findings to account for these signs and symptoms. In this paper, we explore new techniques in the neuroimaging of concussion including diffusion-weighted magnetic resonance imaging and functional brain imaging technology.
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Affiliation(s)
- K M Johnston
- Department of Neurosurgery, McGill University, Montreal, Quebec, Canada
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Johnston KM, Lassonde M, Ptito A. A contemporary neurosurgical approach to sport-related head injury: the McGill concussion protocol. J Am Coll Surg 2001; 192:515-24. [PMID: 11294409 DOI: 10.1016/s1072-7515(01)00797-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- K M Johnston
- Department of Neurosurgery, McGill University Health Center and McGill Sport Medicine, Montreal, Quebec, Canada
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Floyd TF, Cheung AT, Stecker MM. Postoperative neurologic assessment and management of the cardiac surgical patient. Semin Thorac Cardiovasc Surg 2000; 12:337-48. [PMID: 11154729 DOI: 10.1053/stcs.2000.20040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The neurologic evaluation of patients in the immediate postoperative period and postanesthetic state is unique and challenging. Neurologic assessment is complicated by the lingering residual effects of anesthetics as well as by the effects of narcotic analgesics, anxiolytics, and muscle relaxants, especially in ventilated patients. In this review we examine the suspected causes, clinical manifestations, diagnostic options, and intervention schemes for the common neurologic syndromes seen after cardiac operations.
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Affiliation(s)
- T F Floyd
- Department of Anesthesia, University of Pennsylvania, Philadelphia, PA 19104-4283, USA
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Tong DC, Albers GW. Diffusion and perfusion magnetic resonance imaging for the evaluation of acute stroke: potential use in guiding thrombolytic therapy. Curr Opin Neurol 2000; 13:45-50. [PMID: 10719649 DOI: 10.1097/00019052-200002000-00009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recent data indicate that diffusion/perfusion weighted imaging could eventually play a significant role in acute stroke management, particularly in determining the suitability of acute stroke patients for thrombolytic therapy. The evidence supporting these uses is reviewed, and the future role of diffusion and perfusion weighted imaging in acute stroke management is discussed.
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Affiliation(s)
- D C Tong
- Department of Neurology, Stanford University Medical Center, California, USA.
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Anderson RE, Li TQ, Hindmarsh T, Settergren G, Vaage J. Increased extracellular brain water after coronary artery bypass grafting is avoided by off-pump surgery. J Cardiothorac Vasc Anesth 1999; 13:698-702. [PMID: 10622652 DOI: 10.1016/s1053-0770(99)90123-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To determine if coronary artery bypass graft (CABG) surgery without cardiopulmonary bypass (CPB) avoids the brain swelling known to occur after CPB, to quantify these brain water compartment changes, and to identify the water shifts as due to intracellular or extracellular water. DESIGN Prospective, controlled, and blinded. SETTING Cardiac surgical unit in a university teaching hospital. SUBJECTS Patients scheduled for CABG who were assigned to conventional (n = 10) or off-pump (n = 7) surgery according to their coronary anatomy. INTERVENTIONS Magnetic resonance imaging (MRI) examinations were performed 1 day before surgery and 1 hour and 1 week after CABG surgery. MAIN OUTCOME MEASURES Extracellular and intracellular water homeostasis was described quantitatively by calculating the averaged apparent diffusion coefficient of brain water using diffusion-weighted MRI. Blinded visual ordering of the images from the three examinations was performed according to brain size using conventional MRI. RESULTS The average diffusion coefficient of brain water increased 4.7%+/-1.5% immediately after CABG with CPB and normalized after 1 week but did not change after CABG without CPB. No focal ischemic changes were seen in either group, and no gross neurologic deficits were observed. Visual analysis showed consistent brain swelling after CPB and variable changes in those operated without CPB. CONCLUSION Changes consistent with increased extracellular brain water seen after CABG with CPB were not observed in patients undergoing CABG without CPB. The clinical significance of brain water changes and increased brain water content after surgery with CPB remains undefined.
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Affiliation(s)
- R E Anderson
- Department of Cardiothoracic Anaesthetics and Intensive Care, Karolinska MR Research Center, Karolinska Hospital, Stockholm, Sweden
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