Magnetic resonance insights最新文献_第4页

Contrast-enhanced magnetic resonance imaging in pediatric patients: review and recommendations for current practice. 儿科患者的对比增强磁共振成像：回顾与当前实践建议。

Magnetic resonance insights Pub Date : 2013-10-20 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S12561

Ravi Bhargava, Gabriele Hahn, Wolfgang Hirsch, Myung-Joon Kim, Hans-Joachim Mentzel, Oystein E Olsen, Eira Stokland, Fabio Triulzi, Elida Vazquez

{"title":"Contrast-enhanced magnetic resonance imaging in pediatric patients: review and recommendations for current practice.","authors":"Ravi Bhargava, Gabriele Hahn, Wolfgang Hirsch, Myung-Joon Kim, Hans-Joachim Mentzel, Oystein E Olsen, Eira Stokland, Fabio Triulzi, Elida Vazquez","doi":"10.4137/MRI.S12561","DOIUrl":"10.4137/MRI.S12561","url":null,"abstract":"Magnetic resonance imaging (MRI), frequently with contrast enhancement, is the preferred imaging modality for many indications in children. Practice varies widely between centers, reflecting the rapid pace of change and the need for further research. Guide-line changes, for example on contrast-medium choice, require continued practice reappraisal. This article reviews recent developments in pediatric contrast-enhanced MRI and offers recommendations on current best practice. Nine leading pediatric radiologists from internationally recognized radiology centers convened at a consensus meeting in Bordeaux, France, to discuss applications of contrast-enhanced MRI across a range of indications in children. Review of the literature indicated that few published data provide guidance on best practice in pediatric MRI. Discussion among the experts concluded that MRI is preferred over ionizing-radiation modalities for many indications, with advantages in safety and efficacy. Awareness of age-specific adaptations in MRI technique can optimize image quality. Gadolinium-based contrast media are recommended for enhancing imaging quality. The choice of most appropriate contrast medium should be based on criteria of safety, tolerability, and efficacy, characterized in age-specific clinical trials and personal experience. ","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"6 ","pages":"95-111"},"PeriodicalIF":0.0,"publicationDate":"2013-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4089734/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32578636","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

Magnetic Resonance Imaging-derived Flow Parameters for the Analysis of Cardiovascular Diseases and Drug Development. 磁共振成像衍生的血流参数用于心血管疾病分析和药物开发。

Magnetic resonance insights Pub Date : 2013-08-26 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S12195

Dada O Michael, Awojoyogbe O Bamidele, Adesola O Adewale, Boubaker Karem

引用次数: 8

Understanding the morphological mismatch between magnetic susceptibility source and t2* image. 磁化率源与t2*图像在形态上的不匹配。

Magnetic resonance insights Pub Date : 2013-08-01 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S11920

Zikuan Chen, Vince Calhoun

{"title":"Understanding the morphological mismatch between magnetic susceptibility source and t2* image.","authors":"Zikuan Chen, Vince Calhoun","doi":"10.4137/MRI.S11920","DOIUrl":"https://doi.org/10.4137/MRI.S11920","url":null,"abstract":"Background and purpose: Recent research has shown that a T2* image (either magnitude or phase) is not identical to the internal spatial distribution of a magnetic susceptibility (χ) source. In this paper, we examine the reasons behind these differences by looking into the insights of T2*-weighted magnetic resonance imaging (T2*MRI) and provide numerical characterizations of the source/image mismatches by numerical simulations.Methods: For numerical simulations of T2*MRI, we predefine a 3D χ source and calculate the complex-valued T2* image by intravoxel dephasing in presence and absence of diffusion. We propose an empirical α-power model to describe the overall source/image transformation. For a Gaussian-shaped χ source, we numerically characterize the source/image morphological mismatch in terms of spatial correlation and FWHM (full width at half maximum).Results: In theory, we show that the χ-induced fieldmap is morphologically different from the χ source due to dipole effect, and the T2* magnitude image is related to the fieldmap by a quadratic transformation in the small phase angle regime, which imposes an additional morphological change. The numerical simulations with a Gaussian-shaped χ source show that a T2* magnitude image may suffer an overall source/image morphological shrinkage of 20% to 25% and that the T2* phase image is almost identical to the fieldmap thus maintaining a morphological mismatch from the χ source due to dipole effect.Conclusion: The morphological mismatch between a bulk χ source and its T2* image is caused by the 3D convolution during tissue magnetization (dipole effect), the nonlinearity of the T2* magnitude and phase calculation, and the spin diffusion effect. In the small phase angle regime, the T2* magnitude exhibits an overall morphological shrinkage, and the T2* phase image suffers a dipole effect but maintains the χ-induced fieldmap morphology.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"6 ","pages":"65-81"},"PeriodicalIF":0.0,"publicationDate":"2013-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/MRI.S11920","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32578634","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: 20

Measuring restriction sizes using diffusion weighted magnetic resonance imaging: a review. 使用扩散加权磁共振成像测量限制尺寸:综述。

Magnetic resonance insights Pub Date : 2013-05-19 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S11149

Melanie Martin

引用次数: 18

MR Spectroscopic Imaging of Peripheral Zone in Prostate Cancer Using a 3T MRI Scanner: Endorectal versus External Phased Array Coils. 使用3T MRI扫描仪对前列腺癌外周区的磁共振成像:直肠内与外部相控阵线圈。

Magnetic resonance insights Pub Date : 2013-05-15 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S10861

Rajakumar Nagarajan, Daniel Ja Margolis, Steven S Raman, David Ouellette, Manoj K Sarma, Robert E Reiter, M Albert Thomas

{"title":"MR Spectroscopic Imaging of Peripheral Zone in Prostate Cancer Using a 3T MRI Scanner: Endorectal versus External Phased Array Coils.","authors":"Rajakumar Nagarajan, Daniel Ja Margolis, Steven S Raman, David Ouellette, Manoj K Sarma, Robert E Reiter, M Albert Thomas","doi":"10.4137/MRI.S10861","DOIUrl":"https://doi.org/10.4137/MRI.S10861","url":null,"abstract":"Magnetic resonance spectroscopic imaging (MRSI) detects alterations in major prostate metabolites, such as citrate (Cit), creatine (Cr), and choline (Ch). We evaluated the sensitivity and accuracy of three-dimensional MRSI of prostate using an endorectal compared to an external phased array \"receive\" coil on a 3T MRI scanner. Eighteen patients with prostate cancer (PCa) who underwent endorectal MR imaging and proton (1H) MRSI were included in this study. Immediately after the endorectal MRSI scan, the PCa patients were scanned with the external phased array coil. The endorectal coil-detected metabolite ratio [(Ch+Cr)/Cit] was significantly higher in cancer locations (1.667 ± 0.663) compared to non-cancer locations (0.978 ± 0.420) (P < 0.001). Similarly, for the external phased array, the ratio was significantly higher in cancer locations (1.070 ± 0.525) compared to non-cancer locations (0.521 ± 0.310) (P < 0.001). The sensitivity and accuracy of cancer detection were 81% and 78% using the endorectal 'receive' coil, and 69% and 75%, respectively using the external phased array 'receive' coil. ","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"6 ","pages":"51-8"},"PeriodicalIF":0.0,"publicationDate":"2013-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/MRI.S10861","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32578632","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: 3

Magnetic resonance in the detection of breast cancers of different histological types. 磁共振在不同组织学类型乳腺癌检测中的应用。

Magnetic resonance insights Pub Date : 2013-04-30 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S10640

Rebecca M Mayrhofer, Hsiao Piau Ng, Thomas C Putti, Philip W Kuchel

引用次数: 11

Effect of object orientation angle on t2* image and reconstructed magnetic susceptibility: numerical simulations. 物体取向角对t2*像和重构磁化率的影响:数值模拟。

Magnetic resonance insights Pub Date : 2013-02-28 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S11425

Zikuan Chen, Vince Calhoun

引用次数: 8

Mathematical Modeling and Data Analysis of NMR Experiments using Hyperpolarized (13)C Metabolites. 超极化(13)C代谢物核磁共振实验的数学建模和数据分析。

Magnetic resonance insights Pub Date : 2013-02-24 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S11084

Guilhem Pagès, Philip W Kuchel

引用次数: 15

Safety and efficacy of gadobutrol-enhanced MRI in patients aged under 2 years-a single-center, observational study. gadobutrol增强MRI在2岁以下患者中的安全性和有效性-一项单中心观察性研究。

Magnetic resonance insights Pub Date : 2013-02-06 eCollection Date: 2013-01-01 DOI: 10.4137/MRI.S10996

Ravi Bhargava, Michelle Noga

引用次数: 14

Characterization of Intra-myocellular Lipids using 2D Localized Correlated Spectroscopy and Abdominal Fat using MRI in Type 2 Diabetes. 2型糖尿病患者心肌细胞内脂质二维定位相关光谱和腹部脂肪MRI表征

Magnetic resonance insights Pub Date : 2012-10-15 DOI: 10.4137/MRI.S10489

Preethi Srikanthan, Aparna Singhal, Cathy C Lee, Rajakumar Nagarajan, Neil Wilson, Christian K Roberts, Theodore J Hahn, M Albert Thomas

{"title":"Characterization of Intra-myocellular Lipids using 2D Localized Correlated Spectroscopy and Abdominal Fat using MRI in Type 2 Diabetes.","authors":"Preethi Srikanthan, Aparna Singhal, Cathy C Lee, Rajakumar Nagarajan, Neil Wilson, Christian K Roberts, Theodore J Hahn, M Albert Thomas","doi":"10.4137/MRI.S10489","DOIUrl":"https://doi.org/10.4137/MRI.S10489","url":null,"abstract":"A major goal of this pilot study was to quantify intramyocellular lipids (IMCL), extramyocellular lipids (EMCL), unsaturation index (UI) and metabolites such as creatine (Cr), choline (Ch) and carnosine (Car), in the soleus muscle using two-dimensional (2D) localized correlated spectroscopy (L-COSY). Ten subjects with type 2 diabetes (T2D), controlled by lifestyle management alone, and 9 healthy control subjects, were studied. In T2D patients only, the following measurements were obtained: body mass index (BMI); waist circumference (WC); abdominal visceral and subcutaneous fat quantified using breath-held magnetic resonance imaging (MRI); a fasting blood draw for assessment of glucose, insulin, and estimation of homeostasis model assessment of insulin resistance (HOMA-IR), HbA1c, and high-sensitivity c-reactive protein (hs-CRP). Analysis of the soleus muscle 2D L-COSY spectral data showed significantly elevated IMCL ratios with respect to Cr and decreased IMCL UI in T2D when compared to healthy subjects (P < 0.05). In T2D subjects, Pearson correlation analysis showed a positive correlation of IMCL/Cr with EMCL/Cr (0.679, P < 0.05) and HOMA-IR (0.633, P < 0.05), and a non-significant correlation of visceral and subcutaneous fat with magnetic resonance spectroscopy (MRS) and other metrics. Characterization of muscle IMCL and EMCL ratios, UI, and abdominal fat, may be useful for the noninvasive assessment of the role of altered lipid metabolism in the pathophysiology of T2D, and for assessment of the effects of future therapeutic interventions designed to alter metabolic dysfunction in T2D.","PeriodicalId":74096,"journal":{"name":"Magnetic resonance insights","volume":"5 ","pages":"29-36"},"PeriodicalIF":0.0,"publicationDate":"2012-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4137/MRI.S10489","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31290655","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: 24