Magnetic resonance insights最新文献_第5页

Improvements in a Mouse Model of Alzheimer's Disease Through SOD2 Overexpression are Due to Functional and Not Structural Alterations. SOD2过表达对阿尔茨海默病小鼠模型的改善是功能性而非结构性改变所致

Magnetic resonance insights Pub Date : 2012-03-29 DOI: 10.4137/MRI.S9352

Brittany R Bitner, Carlos J Perez-Torres, Lingyun Hu, Taeko Inoue, Robia G Pautler

引用次数: 0

Detection of Amide and Aromatic Proton Resonances of Human Brain Metabolites Using Localized Correlated Spectroscopy Combined with Two Different Water Suppression Schemes. 结合两种不同的水抑制方案的局部相关光谱法检测人脑代谢物的酰胺和芳香质子共振

Magnetic resonance insights Pub Date : 2010-06-15 DOI: 10.4137/MRI.S4739

Rajakumar Nagarajan, Saadallah Ramadan, M Albert Thomas

{"title":"Detection of Amide and Aromatic Proton Resonances of Human Brain Metabolites Using Localized Correlated Spectroscopy Combined with Two Different Water Suppression Schemes.","authors":"Rajakumar Nagarajan, Saadallah Ramadan, M Albert Thomas","doi":"10.4137/MRI.S4739","DOIUrl":"10.4137/MRI.S4739","url":null,"abstract":"The purpose of the study was to demonstrate the J-coupling connectivity network between the amide, aliphatic, and aromatic proton resonances of metabolites in human brain using two-dimensional (2D) localized correlated spectroscopy (L-COSY). Two different global water suppression techniques were combined with L-COSY, one before and another after localizing the volume of interest (VOI). Phantom solutions containing several cerebral metabolites at physiological concentrations were evaluated initially for sequence optimization. Nine healthy volunteers were scanned using a 3T whole body MRI scanner. The VOI for 2D L-COSY was placed in the right occipital white/gray matter region. The 2D cross and diagonal peak volumes were measured for several metabolites such as N-acetyl aspartate (NAA), creatine (Cr), free choline (Ch), glutamate/glutamine (Glx), aspartate (Asp), myo-inositol (mI), GABA, glutathione (GSH), phosphocholine (PCh), phosphoethanolamine (PE), tyrosine (Tyr), lactate (Lac), macromolecules (MM) and homocarnosine (Car). Using the pre-water suppression technique with L-COSY, the above mentioned metabolites were clearly identifiable and the relative ratios of metabolites were calculated. In addition to detecting multitude of aliphatic resonances in the high field region, we have demonstrated that the amide and aromatic resonances can also be detected using 2D L-COSY by pre water suppression more reliably than the post-water suppression.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"2010 4","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2010-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3086031/pdf/nihms286047.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29861460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Increased Human Wildtype Tau Attenuates Axonal Transport Deficits Caused by Loss of APP in Mouse Models. 在小鼠模型中，增加人类野生型Tau可减弱APP缺失引起的轴突运输缺陷。

Magnetic resonance insights Pub Date : 2010-01-01 DOI: 10.4137/mri.s5237

Karen D B Smith, Erica Peethumnongsin, Han Lin, Hui Zheng, Robia G Pautler

{"title":"Increased Human Wildtype Tau Attenuates Axonal Transport Deficits Caused by Loss of APP in Mouse Models.","authors":"Karen D B Smith, Erica Peethumnongsin, Han Lin, Hui Zheng, Robia G Pautler","doi":"10.4137/mri.s5237","DOIUrl":"https://doi.org/10.4137/mri.s5237","url":null,"abstract":"Amyloid precursor protein (APP) is implicated in axonal elongation, synaptic plasticity, and axonal transport. However, the role of APP on axonal transport in conjunction with the microtubule associated protein tau continues to be debated. Here we measured in vivo axonal transport in APP knockout mice with Manganese Enhanced MRI (MEMRI) to determine whether APP is necessary for maintaining normal axonal transport. We also tested how overexpression and mutations of tau affect axonal transport in the presence or absence of APP. In vivo axonal transport reduced significantly in the absence of functional APP. Overexpression of human wildtype tau maintained normal axonal transport and resulted in a transient compensation of axonal transport deficits in the absence of APP. Mutant R406Wtau in combination with the absence of APP compounded axonal transport deficits and these deficits persisted with age. These results indicate that APP is necessary for axonal transport, and overexpression of human wildtype tau can compensate for the absence of APP at an early age.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"4 ","pages":"11-18"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/mri.s5237","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29270850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 28

DANCING WITH THE ELECTRONS: TIME-DOMAIN AND CW IN VIVO EPR IMAGING. 与电子共舞:时域和连续波在体电磁共振成像。

Magnetic resonance insights Pub Date : 2008-09-24 DOI: 10.4137/mri.s1131

Sankaran Subramanian, Murali C Krishna

{"title":"DANCING WITH THE ELECTRONS: TIME-DOMAIN AND CW IN VIVO EPR IMAGING.","authors":"Sankaran Subramanian, Murali C Krishna","doi":"10.4137/mri.s1131","DOIUrl":"https://doi.org/10.4137/mri.s1131","url":null,"abstract":"The progress in the development of imaging the distribution of unpaired electrons in living systems and the functional and the potential diagnostic dimensions of such an imaging process, using Electron Paramagnetic Resonance Imaging (EPRI), is traced from its origins with emphasis on our own work. The importance of EPR imaging stems from the fact that many paramagnetic probes show oxygen dependent spectral broadening. Assessment of in vivo oxygen concentration is an important factor in radiation oncology in treatment-planning and monitoring treatment-outcome. The emergence of narrow-line trairylmethyl based, bio-compatible spin probes has enabled the development of radiofrequency time-domain EPRI. Spectral information in time-domain EPRI can be achieved by generating a time sequence of T(2)* or T(2) weighted images. Progress in CW imaging has led to the use of rotating gradients, more recently rapid scan with direct detection, and a combination of all the three. Very low field MRI employing Dynamic Nuclear polarization (Overhauser effect) is also employed for monitoring tumor hypoxia, and re-oxygenation in vivo. We have also been working on the co-registration of MRI and time domain EPRI on mouse tumor models at 300 MHz using a specially designed resonator assembly. The mapping of the unpaired electron distribution and unraveling the spectral characteristics by using magnetic resonance in presence of stationary and rotating gradients in indeed 'dancing with the (unpaired) electrons', metaphorically speaking.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"2 ","pages":"43-74"},"PeriodicalIF":0.0,"publicationDate":"2008-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/mri.s1131","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30230669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Gender Differences in Musculoskeletal Lipid Metabolism as Assessed by Localized Two-Dimensional Correlation Spectroscopy. 用局部二维相关光谱评估肌肉骨骼脂质代谢的性别差异。

Magnetic resonance insights Pub Date : 2008-09-03

S Sendhil Velan, Nicholas Said, Kartik Narasimhan, Cyrus Papan, Ali Bahu, John Austin Vargo, Raymond R Raylman, M Albert Thomas, Vazhaikkurichi M Rajendran, Richard G Spencer, Stephen E Alway

{"title":"Gender Differences in Musculoskeletal Lipid Metabolism as Assessed by Localized Two-Dimensional Correlation Spectroscopy.","authors":"S Sendhil Velan, Nicholas Said, Kartik Narasimhan, Cyrus Papan, Ali Bahu, John Austin Vargo, Raymond R Raylman, M Albert Thomas, Vazhaikkurichi M Rajendran, Richard G Spencer, Stephen E Alway","doi":"","DOIUrl":"","url":null,"abstract":"Gender differences in lipid metabolism are poorly understood and difficult to study using conventional approaches. Magnetic resonance spectroscopy (MRS) permits non-invasive investigation of lipid metabolism. We employed novel two-dimensional MRS techniques to quantify intramyocellular (IMCL) and extramyocellular (EMCL) lipid compartments and their degree of unsaturation in normal weight adult male and female subjects. Using muscle creatine (Cr) for normalization, a statistically significant (p < 0.05) increase in IMCL/Cr (7.8 ± 1.6) and EMCL/Cr (22.5 ± 3.6) for female subjects was observed (n=8), as compared to IMCL/Cr (5.9 ± 1.7) and EMCL/Cr (18.4 ± 2.64) for male subjects. The degree of unsaturation within IMCL and EMCL was lower in female subjects, 1.3 ± 0.075 and 1.04 ± 0.06, respectively, as compared to that observed in males (n=8), 1.5 ± 0.08 and 1.12 ± 0.03, respectively (p < 0.05 male vs female for both comparisons). We conclude that certain salient gender differences in lipid metabolism can be assessed noninvasively by advanced MRS approaches.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"2008 2","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2008-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4216805/pdf/nihms73064.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32792914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Gender Differences in Musculoskeletal Lipid Metabolism as Assessed by Localized Two-Dimensional Correlation Spectroscopy. 用局部二维相关光谱评估肌肉骨骼脂质代谢的性别差异。

Magnetic resonance insights Pub Date : 2008-09-03 DOI: 10.4137/MRI.S958

S. Velan, Nicholas Said, Kartik Narasimhan, C. Papan, A. Bahu, J. Vargo, R. Raylman, M. Thomas, V. Rajendran, R. Spencer, S. Alway

{"title":"Gender Differences in Musculoskeletal Lipid Metabolism as Assessed by Localized Two-Dimensional Correlation Spectroscopy.","authors":"S. Velan, Nicholas Said, Kartik Narasimhan, C. Papan, A. Bahu, J. Vargo, R. Raylman, M. Thomas, V. Rajendran, R. Spencer, S. Alway","doi":"10.4137/MRI.S958","DOIUrl":"https://doi.org/10.4137/MRI.S958","url":null,"abstract":"Gender differences in lipid metabolism are poorly understood and difficult to study using conventional approaches. Magnetic resonance spectroscopy (MRS) permits non-invasive investigation of lipid metabolism. We employed novel two-dimensional MRS techniques to quantify intramyocellular (IMCL) and extramyocellular (EMCL) lipid compartments and their degree of unsaturation in normal weight adult male and female subjects. Using muscle creatine (Cr) for normalization, a statistically significant (p < 0.05) increase in IMCL/Cr (7.8 ± 1.6) and EMCL/Cr (22.5 ± 3.6) for female subjects was observed (n=8), as compared to IMCL/Cr (5.9 ± 1.7) and EMCL/Cr (18.4 ± 2.64) for male subjects. The degree of unsaturation within IMCL and EMCL was lower in female subjects, 1.3 ± 0.075 and 1.04 ± 0.06, respectively, as compared to that observed in males (n=8), 1.5 ± 0.08 and 1.12 ± 0.03, respectively (p < 0.05 male vs female for both comparisons). We conclude that certain salient gender differences in lipid metabolism can be assessed noninvasively by advanced MRS approaches.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"2008 2 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2008-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/MRI.S958","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70711244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Role of Magnetic Resonance in Understanding the Pathogenesis of Hepatic Encephalopathy. 磁共振在了解肝性脑病发病机制中的作用。

Magnetic resonance insights Pub Date : 2008-01-01 DOI: 10.4137/mri.s973

A Huda, R K Gupta, N Rajakumar, M A Thomas

引用次数: 0