Radial magnetic resonance imaging (MRI) using a rotating radiofrequency (RF) coil at 9.4 T
The rotating radiofrequency coil (RRFC) has been developed recently as an alternative approach to multi‐channel phased‐array coils. The single‐element RRFC avoids inter‐channel coupling and allows a larger coil element with better B1 field penetration when compared with an array counterpart. However, dedicated image reconstruction algorithms require accurate estimation of temporally varying coil sensitivities to remove artefacts caused by coil rotation. Various methods have been developed to estimate unknown sensitivity profiles from a few experimentally measured sensitivity maps, but these methods become problemat...
Source: NMR in Biomedicine - December 27, 2017 Category: Radiology Authors: Mingyan Li, Ewald Weber, Jin Jin, Thimo Hugger, Yasvir Tesiram, Peter Ullmann, Simon Stark, Miguel Fuentes, Sven Junge, Feng Liu, Stuart Crozier Tags: RESEARCH ARTICLE Source Type: research
An eight ‐channel sodium/proton coil for brain MRI at 3 T
The purpose of this work is to illustrate a new coil decoupling strategy and its application to a transmit/receive sodium/proton phased array for magnetic resonance imaging (MRI) of the human brain. We implemented an array of eight triangular coils that encircled the head. The ensemble of coils was arranged to form a modified degenerate mode birdcage whose eight shared rungs were offset from the z‐axis at interleaved angles of ±30°. This key geometric modification resulted in triangular elements whose vertices were shared between next‐nearest neighbors, which provided a convenient location for counter‐wound decoupl...
Source: NMR in Biomedicine - December 27, 2017 Category: Radiology Authors: Karthik Lakshmanan, Ryan Brown, Guillaume Madelin, Yongxian Qian, Fernando Boada, Graham C. Wiggins Tags: RESEARCH ARTICLE Source Type: research
Assessment of the need for DCE MRI in the detection of dominant lesions in the whole gland: Correlation between histology and MRI of prostate cancer
The purpose of this study was to evaluate the utility of dynamic contrast‐enhanced magnetic resonance imaging (DCE MRI) in the detection of dominant prostate tumors with multi‐parametric MRI of the whole gland. Combined diffusion tensor imaging (DTI) and DCE MRI from 16 patients with biopsy‐proven prostate cancer and no previous treatment were acquired with a 3.0‐T MRI scanner prior to radical prostatectomy, and used to identify dominant tumors. MRI results were validated by whole‐mount histology. Paired t‐test and Wilcoxon test, logistic generalized linear mixed effect models and receiver operating characteris...
Source: NMR in Biomedicine - December 20, 2017 Category: Radiology Authors: Piotr Kozlowski, Silvia D. Chang, Edward C. Jones, S. Larry Goldenberg Tags: RESEARCH ARTICLE Source Type: research
Altered macromolecular pattern and content in the aging human brain
The resonances originating from proteins underlie those of metabolites in brain 1H nuclear magnetic resonance (NMR) spectra. These resonances have different physical properties from those of metabolites, such as shorter T1 and T2 relaxation time constants. The age dependence of the macromolecular pattern and content in the human brain was investigated with a focus on adults over 66 years of age using ultrahigh‐field in vivo magnetic resonance spectroscopy. Eighteen young and 23 cognitively normal older adults were studied at 7 T. Metabolite spectra were acquired in the occipital cortex and the posterior cingulate corte...
Source: NMR in Biomedicine - December 20, 2017 Category: Radiology Authors: Ma łgorzata Marjańska, Dinesh K. Deelchand, James S. Hodges, J. Riley McCarten, Laura S. Hemmy, Andrea Grant, Melissa Terpstra Tags: RESEARCH ARTICLE Source Type: research
Retrospective motion gating in cardiac MRI using a simultaneously acquired navigator
A simultaneous acquisition technique of image and navigator signals (simultaneously acquired navigator, SIMNAV) is proposed for cardiac magnetic resonance imaging (CMRI) in Cartesian coordinates. To simultaneously acquire both image and navigator signals, a conventional balanced steady‐state free precession (bSSFP) pulse sequence is modified by adding a radiofrequency (RF) pulse, which excites a supplementary slice for the navigator signal. Alternating phases of the RF pulses make it easy to separate the simultaneously acquired magnetic resonance data into image and navigator signals. The navigator signals of the propose...
Source: NMR in Biomedicine - December 20, 2017 Category: Radiology Authors: Byungjai Kim, Hyunseok Seo, Dongchan Kim, HyunWook Park Tags: RESEARCH ARTICLE Source Type: research
Utility of gradient recalled echo magnetic resonance imaging for the study of myelination in cuprizone mice treated with fingolimod
In this study, we evaluated the sensitivity of T2*, frequency shift and susceptibility measures to myelin levels in a cuprizone mouse model of demyelination. The model was supplemented with two different dosages of fingolimod, a drug known to positively affect demyelination. A decrease in grey–white matter contrast with the cuprizone diet was observed for T2*, frequency shift and susceptibility measures, together with myelin basic protein antibody findings. These results indicate that T2*, frequency shift and susceptibility measures have the potential to act as biomarkers for myelination. Susceptibility was found to be t...
Source: NMR in Biomedicine - December 20, 2017 Category: Radiology Authors: Laura Ziser, Naja Meyer ‐Schell, Nyoman D. Kurniawan, Robert Sullivan, David Reutens, Min Chen, Viktor Vegh Tags: RESEARCH ARTICLE Source Type: research
Non ‐invasive diagnosis and metabolic consequences of congenital portosystemic shunts in C57BL/6 J mice
This study demonstrates the suitability of magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) for the imaging of congenital portosystemic shunts (PSS) in mice, a vascular abnormality in which mesenteric blood bypasses the liver and is instead drained directly to the systemic circulation. The non‐invasive diagnosis performed in tandem with other experimental assessments permits further characterization of liver, whole‐body and brain metabolic defects associated with PSS. Magnetic resonance measurements were performed in a 26‐cm, horizontal‐bore, 14.1‐T magnet. MRA was obtained with a three...
Source: NMR in Biomedicine - December 20, 2017 Category: Radiology Authors: Ana Francisca Soares, Hongxia Lei Tags: RESEARCH ARTICLE Source Type: research
Issue Information
No abstract is available for this article. (Source: NMR in Biomedicine)
Source: NMR in Biomedicine - December 18, 2017 Category: Radiology Tags: ISSUE INFORMATION Source Type: research
Cover Image, Volume 31, Issue 1
The cover image, by Byeong‐Yeul Lee et al., is based on the Research Article Interleaved 31P MRS imaging of human frontal and occipital lobes using dual RF coils in combination with single‐channel transmitter–receiver and dynamic B0shimming, DOI: 10.1002/nbm.3842. (Source: NMR in Biomedicine)
Source: NMR in Biomedicine - December 18, 2017 Category: Radiology Authors: Byeong ‐Yeul Lee, Xiao‐Hong Zhu, Myung Kyun Woo, Gregor Adriany, Scott Schillak, Wei Chen Tags: COVER IMAGE Source Type: research
Diffusion ‐weighted imaging features of breast tumours and the surrounding stroma reflect intrinsic heterogeneous characteristics of molecular subtypes in breast cancer
Breast cancer heterogeneity is the main obstacle preventing the identification of patients with breast cancer with poor prognoses and treatment responses; however, such heterogeneity has not been well characterized. The purpose of this retrospective study was to reveal heterogeneous patterns in the apparent diffusion coefficient (ADC) signals in tumours and the surrounding stroma to predict molecular subtypes of breast cancer. A dataset of 126 patients with breast cancer, who underwent preoperative diffusion‐weighted imaging (DWI) on a 3.0‐T image system, was collected. Breast images were segmented into regions compris...
Source: NMR in Biomedicine - December 15, 2017 Category: Radiology Authors: Ming Fan, Ting He, Peng Zhang, Hu Cheng, Juan Zhang, Xin Gao, Lihua Li Tags: RESEARCH ARTICLE Source Type: research
High ‐resolution hyperpolarized metabolic imaging of the rat heart using k–t PCA and k–t SPARSE
The purpose of this work was to increase the resolution of hyperpolarized metabolic imaging of the rat heart with accelerated imaging using k–t principal component analysis (k–t PCA) and k–t compressed sensing (k–t SPARSE). Fully sampled in vivo datasets were acquired from six healthy rats after the injection of hyperpolarized [1‐13C]pyruvate. Data were retrospectively undersampled and reconstructed with either k–t PCA or k–t SPARSE. Errors of signal–time curves of pyruvate, lactate and bicarbonate were determined to compare the two reconstruction algorithms for different undersampling factors R. Prospectiv...
Source: NMR in Biomedicine - December 15, 2017 Category: Radiology Authors: Patrick Wespi, Jonas Steinhauser, Grzegorz Kwiatkowski, Sebastian Kozerke Tags: RESEARCH ARTICLE Source Type: research
The follow ‐up of progressive hypertrophic cardiomyopathy using magnetic resonance rotating frame relaxation times
Magnetic resonance rotating frame relaxation times are an alternative non‐contrast agent choice for the diagnosis of chronic myocardial infarct. Fibrosis typically occurs in progressive hypertrophic cardiomyopathy. Fibrosis has been imaged in myocardial infarcted tissue using rotating frame relaxation times, which provides the possibility to follow up progressive cardiomyopathy without contrast agents. Mild and severe left ventricular hypertrophy were induced in mice by transverse aortic constriction, and the longitudinal rotating frame relaxation times (T1ρ) and relaxation along the fictitious field (TRAFF2, TRAFF3) we...
Source: NMR in Biomedicine - December 15, 2017 Category: Radiology Authors: Muhammad Arsalan Khan, Hanne Laakso, Svetlana Laidinen, Sanna Kettunen, Tommi Heikura, Seppo Yl ä‐Herttuala, Timo Liimatainen Tags: RESEARCH ARTICLE Source Type: research
The two faces of enhanced stroma: Stroma acts as a tumor promoter and a steric obstacle
NMR in Biomedicine, EarlyView. (Source: NMR in Biomedicine)
Source: NMR in Biomedicine - December 7, 2017 Category: Radiology Source Type: research
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NMR in Biomedicine, Ahead of Print. (Source: NMR in Biomedicine)
Source: NMR in Biomedicine - December 7, 2017 Category: Radiology Source Type: research
The two faces of enhanced stroma: Stroma acts as a tumor promoter and a steric obstacle
In addition to genetic, morphological and biochemical alterations in cells, a key feature of the malignant progression of cancer is the stroma, including cancer cell motility as well as the emergence of metastases. Our current knowledge with regard to the biophysically driven experimental approaches of cancer progression indicates that mechanical aberrations are major contributors to the malignant progression of cancer. In particular, the mechanical probing of the stroma is of great interest. However, the impact of the tumor stroma on cellular motility, and hence the metastatic cascade leading to the malignant progression ...
Source: NMR in Biomedicine - December 7, 2017 Category: Radiology Authors: Claudia Tanja Mierke, Frank Sauer, Steffen Grosser, Stefanie Puder, Tony Fischer, Josef Alfons K äs Tags: SPECIAL ISSUE REVIEW ARTICLE Source Type: research
