A comparison of readout segmented EPI and interleaved EPI in high-resolution diffusion weighted imaging
To provide a comprehensive understanding of multi-shot EPI diffusion imaging methods by comparing Readout segmented EPI (RS-EPI) and interleaved EPI (iEPI). (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 23, 2017 Category: Radiology Authors: Yishi Wang, Xiaodong Ma, Zhe Zhang, Erpeng Dai, Ha-Kyu Jeong, Bin Xie, Chun Yuan, Hua Guo Tags: Original contribution Source Type: research
White matter structural integrity and transcranial Doppler blood flow pulsatility in normal aging
Cerebrovascular diseases underlie many forms of age-related cognitive impairment and the mechanism linking the two is hypothesized to involve adverse changes in white matter (WM) integrity. Despite being systemic, small vessel disease does not uniformly affect WM. We performed voxel-wise analysis of MRI images to examine the association between fractional anisotropy (FA) — a diffusion tensor measure of WM structural integrity — and pulsatility index (PI) — a transcranial Doppler ultrasound measure of abnormal arterial flow — in adults over the age of 70years who were free of stroke and dementia. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 20, 2017 Category: Radiology Authors: Roman Fleysher, Michael L Lipton, Olga Noskin, Tatjana Rundek, Richard Lipton, Carol A. Derby Tags: Original contribution Source Type: research
Diffusion kurtosis imaging with the breath-hold technique for staging hepatic fibrosis: A preliminary study
To evaluate the potential of diffusion kurtosis imaging (DKI) analysis with the breath-hold technique to assess the stage or classify hepatic fibrosis. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 20, 2017 Category: Radiology Authors: Daisuke Yoshimaru, Toshiaki Miyati, Yuichi Suzuki, Yuhki Hamada, Nozomi Mogi, Ayumu Funaki, Ayumi Tabata, Atsuko Masunaga, Masahiko Shimada, Maki Tobari, Takayoshi Nishino Tags: Original contribution Source Type: research
White Matter Structural Integrity and Trans-Cranial Doppler Blood Flow Pulsatility in Normal Aging
Cerebrovascular diseases underlie many forms of age-related cognitive impairment and the mechanism linking the two is hypothesized to involve adverse changes in white matter (WM) integrity. Despite being systemic, small vessel disease does not uniformly affect WM. We performed voxel-wise analysis of MRI images to examine the association between fractional anisotropy (FA) — a diffusion tensor measure of WM structural integrity — and pulsatility index (PI) — a transcranial Doppler ultrasound measure of abnormal arterial flow — in adults over the age of 70 years who were free of stroke and dementia. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 20, 2017 Category: Radiology Authors: Roman Fleysher, Michael L Lipton, Olga Noskin, Tatjana Rundek, Richard Lipton, Carol A. Derby Source Type: research
Linearization improves the repeatability of quantitative dynamic contrast-enhanced MRI
The purpose of this study was to compare the repeatabilities of the linear and nonlinear Tofts and reference region models (RRM) for dynamic contrast-enhanced MRI (DCE-MRI). (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 15, 2017 Category: Radiology Authors: Kyle M. Jones, Mark D. Pagel, Julio C árdenas-Rodríguez Tags: Original contribution Source Type: research
Identification of ghost artifact using texture analysis in pediatric spinal cord diffusion tensor images
Ghost artifacts are a major contributor to degradation of spinal cord diffusion tensor images. A multi-stage post-processing pipeline was designed, implemented and validated to automatically remove ghost artifacts arising from reduced field of view diffusion tensor imaging (DTI) of the pediatric spinal cord. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 15, 2017 Category: Radiology Authors: Mahdi Alizadeh, Chris J. Conklin, Devon M. Middleton, Pallav Shah, Sona Saksena, Laura Krisa, J ürgen Finsterbusch, Scott H. Faro, M.J. Mulcahey, Feroze B. Mohamed Source Type: research
Nonrigid motion compensation in compressed sensing reconstruction of cardiac cine MRI
In this work, a robust nonrigid motion compensation approach, is applied to the compressed sensing reconstruction of dynamic cardiac cine MRI sequences. Respiratory and cardiac motion separation coupled with a registration algorithm is used to provide accurate reconstruction of dynamic cardiac images. The proposed scheme employs a variable splitting based optimization strategy to enable joint motion estimation along with reconstruction. We define the recovery as an energy minimization scheme utilizing an objective function that combines data consistency, spatial smoothness, and motion penalties. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 14, 2017 Category: Radiology Authors: Azar Tolouee, Javad Alirezaie, Paul Babyn Tags: Original contribution Source Type: research
An interleaved sequence for simultaneous magnetic resonance angiography (MRA), susceptibility weighted imaging (SWI) and quantitative susceptibility mapping (QSM)
To image the entire vasculature of the brain with complete suppression of signal from background tissue using a single 3D excitation interleaved rephased/dephased multi-echo gradient echo sequence. This ensures no loss of signal from fast flow and provides co-registered susceptibility weighted images (SWI) and quantitative susceptibility maps (QSM) from the same scan. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 14, 2017 Category: Radiology Authors: Yongsheng Chen, Saifeng Liu, Sagar Buch, Jiani Hu, Yan Kang, E. Mark Haacke Tags: Technical note Source Type: research
Evaluation of dynamic contrast-enhanced MRI biomarkers for stratified cancer medicine: How do permeability and perfusion vary between human tumours?
Solid tumours exhibit enhanced vessel permeability and fenestrated endothelium to varying degree, but it is unknown how this varies in patients between and within tumour types. Dynamic contrast-enhanced (DCE) MRI provides a measure of perfusion and permeability, the transfer constant Ktrans, which could be employed for such comparisons in patients. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 14, 2017 Category: Radiology Authors: Ross A. Little, Herv é Barjat, Jennifer I. Hare, Mary Jenner, Yvonne Watson, Susan Cheung, Katherine Holliday, Weijuan Zhang, James P.B. O'Connor, Simon T. Barry, Sanyogitta Puri, Geoffrey J.M. Parker, John C. Waterton Tags: Original contribution Source Type: research
Non-contrast quantitative pulmonary perfusion using flow alternating inversion recovery at 3T: A preliminary study
To demonstrate the initial feasibility of non-contrast quantitative pulmonary perfusion imaging at 3T using flow alternating inversion recovery (FAIR), and to evaluate the intra-session and inter-session reliability of FAIR measurements at 3T. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 14, 2017 Category: Radiology Authors: Joshua S. Greer, Christopher D. Maroules, Orhan K. Oz, Suhny Abbara, Ronald M. Peshock, Ivan Pedrosa, Ananth J. Madhuranthakam Tags: Original contribution Source Type: research
Diffusion tensor imaging of spinal cord parenchyma lesion in rat with chronic spinal cord injury
Adequate evaluation of spinal cord parenchyma and accurate identification of injury range are considered two premises for the research and treatment of chronic spinal cord injury (SCI). Diffusion tensor imaging (DTI) provides information about water diffusion in spinal cord, and thus makes it possible to realize these premises. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 14, 2017 Category: Radiology Authors: Can Zhao, Jia-Sheng Rao, Xiao-Jiao Pei, Jian-Feng Lei, Zhan-Jing Wang, Wen Zhao, Rui-Han Wei, Zhao-Yang Yang, Xiao-Guang Li Tags: Original contribution Source Type: research
Efficient Operator Splitting Algorithm for Joint Sparsity-Regularized SPIRiT-based Parallel MR Imaging Reconstruction
Self-consistent parallel imaging (SPIRiT) is an auto-calibrating model for the reconstruction of parallel magnetic resonance imaging, which can be formulated as a regularized SPIRiT problem. The Projection Over Convex Sets (POCS) method was used to solve the formulated regularized SPIRiT problem. However, the quality of the reconstructed image still needs to be improved. Though methods such as NonLinear Conjugate Gradients (NLCG) can achieve higher spatial resolution, these methods always demand very complex computation and converge slowly. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 8, 2017 Category: Radiology Authors: Jizhong Duan, Yu Liu, Peiguang Jing Source Type: research
Is breast MRI a helpful additional diagnostic test in suspicious mammographic microcalcifications?
Microcalcifications are a common finding in mammography and usually require invasive procedures to diagnose or exclude malignancy. As many microcalcifications are due to benign lesions, we wanted to assess whether breast MRI as an additional diagnostic tool may be used to distinguish benign from malignant in this setting. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 6, 2017 Category: Radiology Authors: Pascal A.T. Baltzer, Barbara Bennani-Baiti, Alexander St öttinger, Alexander Bumberger, Panagiotis Kapetas, Paola Clauser Tags: Original contribution Source Type: research
Estimation of physiological sources of nonlinearity in blood oxygenation level-dependent contrast signals
Blood oxygenation level-dependent (BOLD) contrast appears through a variation in the transverse relaxation rate of magnetic resonance signals induced by neurovascular coupling and is known to have nonlinear characteristics along echo time (TE) due to the intra-vasculature. However, the physiological causes of this nonlinearity are unclear. We attempted to estimate the physiological information related to the nonlinearity of BOLD signals by using a two-compartment model. For this purpose, we used a multi-echo gradient-echo echo-planar imaging sequence and developed a computational method to estimate the physiological inform...
Source: Magnetic Resonance Imaging - November 6, 2017 Category: Radiology Authors: Daehun Kang, Yul-Wan Sung, Satoshi Shioiri Tags: Original contribution Source Type: research
Magnetic Resonance Imaging with RF Encoding on Curved Natural Slices
While the idea of using spatial encoding fields (SEM) for image formation has been proven, conventional wisdom still holds that a magnetic resonance imaging (MRI) system begins with a highly uniform magnetic field. In particular, radio frequency (RF) encoding MRIs designed and tested to date have largely used uniform magnetic fields. Here we demonstrate magnetic resonance imaging in a magnetic field with a built-in gradient that gives non-planar slices – curved surfaces – when the nuclear spins are excited with narrow band RF pulses. (Source: Magnetic Resonance Imaging)
Source: Magnetic Resonance Imaging - November 3, 2017 Category: Radiology Authors: Gordon E. Sarty, Logi Vidarrson Source Type: research
