bluuebunny/crossref_metadata_2025_split huggingface dataset:
Traditional Japanese diet and prostate cancer
Authors: Mori Mitsuru , Masumori Naoya , Fukuta Fumimasa , Nagata Yoshie , Sonoda Tomoko , Sakauchi Fumio , Ohnishi Hirofumi , Nojima Masanori , Tsukamoto Taiji 
Published: December 2008

AbstractThe traditional Japanese diet has been suggested by some researchers to be associated with a decreased risk of prostate cancer (PCa). In this paper, we assumed the following three characteristics of the traditional Japanese diet high in soybean products, high in fish, and low in red meat. Isoflavones, polyunsaturated long chain (n – 3) fatty acids, and saturated fatty acids were thought to be micronutrients in biological etiology relevant to soybean products, fish, and red meat, respectively. Analytical epidemiological studies on the risk of PCa were identified using the MEDLINE database from 1998 to 2007. Some published studies showed a negative association of soybean products and isoflavones to PCa risk, an inverse association for fish or polyunsaturated long chain (n – 3) fatty acids such as eicosapentaenic acid (EPA) and docosahexaenoic acid (DHA) with PCa risk, and a positive association of red meat or saturated fatty acids with PCa risk, respectively. In conclusion, although it is possible that the traditional Japanese diet may reduce the risk of PCa through a combination of characteristics such as being high in soybean products, high in fish, and low in red meat, further well‐designed epidemiological studies such as nested case‐control studies with nutritional analyses of blood samples are needed to confirm this association.
On the steady‐state properties of actual flip angle imaging (AFI)
Authors: Nehrke Kay 
Published: December 2008

AbstractAFI (actual flip angle imaging) represents an interesting approach to map the B1 transmit fields by measuring the spatial variations of the effective flip angle. However, the accuracy of the technique relies on the adequate spoiling of transverse magnetization. In the present work configuration theory was employed to develop a proper RF and gradient spoiling scheme for the AFI technique, making the sequence robust against off‐resonance without the need of large spoiling gradients. Furthermore, numerical simulations were performed to predict the steady‐state signals and, hence, the accuracy of the AFI technique as a function of the sequence and tissue parameters. It is shown that the spoiling properties of the sequence are mainly defined by the phase shift increment ϕ of the RF pulses and the diffusion sensitivity resulting from the unbalanced gradients of the sequence. Adequate spoiling may be achieved for a reasonable range of tissue parameters and flip angles for moderate spoiling gradients if a favorable value for ϕ is chosen. Phantom and in vivo head imaging experiments show an excellent agreement with the theoretical predictions, indicating that the proper operating range of the approach may be reliably predicted by the theory. Magn Reson Med 61:84–92, 2009. © 2008 Wiley‐Liss, Inc.
Rapid monitoring of oxygenation by 19F magnetic resonance imaging: Simultaneous comparison with fluorescence quenching
Authors: Jordan Bénédicte F. , Cron Greg O. , Gallez Bernard 
Published: December 2008

AbstractThe aim of this study was to develop an MRI fluorocarbon oximetry technique using snapshot inversion recovery and compare it with fluorescence quenching fiber‐optic probe oximetry (OxyLite) performed simultaneously in experimental mouse tumors. The oxygen reporter probe hexafluorobenzene (HFB) was injected directly into the tumors, along with the insertion of the OxyLite probe. Tumor oxygenation (pO2) was modified using carbogen or lethal doses of the anesthetic gas. MRI pO2 maps were generated in 1.5 min with an in‐plane spatial resolution of 1.88 mm. MRI and OxyLite showed consistent baseline and postmortem pO2 values. Increases in tumor pO2 during carbogen breathing showed similar kinetics for the two methods. The pO2 values observed using the OxyLite corresponded with relatively hypoxic values observed by MRI. The apparent discrepancy between mean values might be due to the difference in sampling volumes of the techniques and the observation of multiple locations using 19F MRI versus a single location using the large optical fiber. Overall, the present method provides a rapid way to map the tumor oxygenation and is particularly suitable to monitor acute changes of pO2 in tumors. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.
Virtual coil concept for improved parallel MRI employing conjugate symmetric signals
Authors: Blaimer Martin , Gutberlet Marcel , Kellman Peter , Breuer Felix A. , Köstler Herbert , Griswold Mark A. 
Published: December 2008

AbstractA new approach for utilizing conjugate k‐space symmetry for improved parallel MRI performance is presented. By generating virtual coils containing conjugate symmetric k‐space signals from actual coils, additional image‐ and coil‐phase information can be incorporated into the reconstruction process for parallel acquisition techniques. In that way the reconstruction conditions are improved, resulting in less noise enhancement. In particular in combination with generalized autocalibrating partially parallel acquisitions (GRAPPA), the virtual coil concept represents a practical approach since no explicit spatial phase information is required. In addition, the influence of phase variations originating from the complex receiver coils as well as from the background is investigated. It is shown that there exist background phase distributions yielding an optimized pMRI reconstruction. Magn Reson Med 61:93–102, 2009. © 2008 Wiley‐Liss, Inc.
Multiecho dixon fat and water separation method for detecting fibrofatty infiltration in the myocardium
Authors: Kellman Peter , Hernando Diego , Shah Saurabh , Zuehlsdorff Sven , Jerecic Renate , Mancini Christine , Liang Zhi‐Pei , Arai Andrew E. 
Published: December 2008

AbstractConventional approaches for fat and water discrimination based on chemical‐shift fat suppression have reduced ability to characterize fatty infiltration due to poor contrast of microscopic fat. The multiecho Dixon approach to water and fat separation has advantages over chemical‐shift fat suppression: 1) water and fat images can be acquired in a single breathhold, avoiding misregistration; 2) fat has positive contrast; 3) the method is compatible with precontrast and late‐enhancement imaging, 4) less susceptible to partial‐volume effects, and 5) robust in the presence of background field variation; and 6) for the bandwidth implemented, chemical‐shift artifact is decreased. The proposed technique was applied successfully in all 28 patients studied. This included 10 studies with indication of coronary artery disease (CAD), of which four cases with chronic myocardial infarction (MI) exhibited fatty infiltration; 13 studies to rule out arrhythmogenic right ventricular cardiomyopathy (ARVC), of which there were three cases with fibrofatty infiltration and two confirmed with ARVC; and five cases of cardiac masses (two lipomas). The precontrast contrast‐to‐noise ratio (CNR) of intramyocardial fat was greatly improved, by 240% relative to conventional fat suppression. For the parameters implemented, the signal‐to‐noise ratio (SNR) was decreased by 30% relative to conventional late enhancement. The multiecho Dixon method for fat and water separation provides a sensitive means of detecting intramyocardial fat with positive signal contrast. Magn Reson Med 61:215–221, 2009. © 2008 Wiley‐Liss, Inc.
k‐t FOCUSS: A general compressed sensing framework for high resolution dynamic MRI
Authors: Jung Hong , Sung Kyunghyun , Nayak Krishna S. , Kim Eung Yeop , Ye Jong Chul 
Published: December 2008

AbstractA model‐based dynamic MRI called k‐t BLAST/SENSE has drawn significant attention from the MR imaging community because of its improved spatio‐temporal resolution. Recently, we showed that the k‐t BLAST/SENSE corresponds to the special case of a new dynamic MRI algorithm called k‐t FOCUSS that is optimal from a compressed sensing perspective. The main contribution of this article is an extension of k‐t FOCUSS to a more general framework with prediction and residual encoding, where the prediction provides an initial estimate and the residual encoding takes care of the remaining residual signals. Two prediction methods, RIGR and motion estimation/compensation scheme, are proposed, which significantly sparsify the residual signals. Then, using a more sophisticated random sampling pattern and optimized temporal transform, the residual signal can be effectively estimated from a very small number of k‐t samples. Experimental results show that excellent reconstruction can be achieved even from severely limited k‐t samples without aliasing artifacts. Magn Reson Med 61:103–116, 2009. © 2008 Wiley‐Liss, Inc.
STAR and STARFIRE for flow‐dependent and flow‐independent noncontrast carotid angiography
Authors: Koktzoglou Ioannis , Edelman Robert R. 
Published: December 2008

AbstractSignal Targeting with Alternating Radiofrequency (STAR) and STAR and Flow‐Independent Relaxation Enhancement (STARFIRE) are noncontrast methods for flow‐dependent and flow‐independent magnetic resonance angiography (MRA). The methods rely on the acquisition and complex subtraction of two image sets alternately labeled by spatially selective or spatially nonselective inversion radio frequency (RF) pulses. Experimental results show that the RF labeling period affects the extent of the carotid vessels seen with STAR imaging, and the conspicuity of cerebrospinal fluid (CSF) and fat in the STARFIRE images. Both methods were found to provide more detailed depiction of the carotid arteries than the alternative noncontrast MRA technique of time‐of‐flight (TOF) angiography. Magn Reson Med 61:117–124, 2009. © 2008 Wiley‐Liss, Inc.
3D blood flow characteristics in the carotid artery bifurcation assessed by flow‐sensitive 4D MRI at 3T
Authors: Harloff A. , Albrecht F. , Spreer J. , Stalder A.F. , Bock J. , Frydrychowicz A. , Schöllhorn J. , Hetzel A. , Schumacher M. , Hennig J. , Markl M. 
Published: December 2008

AbstractTo determine three‐dimensional (3D) blood flow patterns in the carotid bifurcation, 10 healthy volunteers and nine patients with internal carotid artery (ICA) stenosis ≥50% were examined by flow‐sensitive 4D MRI at 3T. Absolute and mean blood velocities, pulsatility index (PI), and resistance index (RI) were measured in the common carotid arteries (CCAs) by duplex sonography (DS) and compared with flow‐sensitive 4D MRI. Furthermore, 3D MRI blood flow patterns in the carotid bifurcation of volunteers and patients before and after recanalization were graded by two independent readers. Blood flow velocities measured by MRI were 31–39% lower than in DS. However, PI and RI differed by only 13–16%. Rating of 3D flow characteristics in the ICA revealed consistent patterns for filling and helical flow in volunteers. In patients with ICA stenosis, 3D blood flow visualization was successfully employed to detect markedly altered filling and helical flow patterns (forward‐moving spiral flow) in the ICA bulb and to evaluate the effect of revascularization, which restored filling and helical flow. Our results demonstrate the feasibility of flow‐sensitive 4D MRI for the quantification and 3D visualization of physiological and pathological flow patterns in the carotid artery bifurcation. Magn Reson Med 61:65–74, 2009. © 2008 Wiley‐Liss, Inc.
Imaging and analysis of lenticulostriate arteries using 7.0‐Tesla magnetic resonance angiography
Authors: Kang Chang‐Ki , Park Cheol‐Wan , Han Jae‐Yong , Kim Sang‐Hoon , Park Chan‐A , Kim Kyoung‐Nam , Hong Suk‐Min , Kim Young‐Bo , Lee Kendall H. , Cho Zang‐Hee 
Published: December 2008

AbstractThe purpose of this study was to analyze human lenticulostriate arteries (LSAs) obtained non‐invasively by 7.0‐T MRI. A three‐dimensional time‐of‐flight (3D TOF) magnetic resonance angiography (MRA) technique was used with an investigational 7.0‐T MRI scanner with a radio‐frequency coil that was optimized and designed for angiographic purposes. We obtained images from 16 healthy volunteers (8 males and 8 females, mean age 21 ± 2.7 years). For direct comparison of LSA images with digital subtraction angiography (DSA), we also obtained 7.0‐T MRA and DSA images from one patient, a 27‐year‐old woman with a posterior fossa arteriovenous malformation (AVM). We then analyzed the characteristics of LSAs using a custom data analysis method with MatLab for quantitative analysis. Analysis of LSA images included shape and number of branches and origins, findings that are essential and useful for quantification of LSA abnormalities in both healthy controls and patients. Ultra–high‐field MRA provided clear anatomic delineation of the LSAs, thereby suggesting that 7.0‐T MRA may be a promising technique for microvascular imaging of the LSAs. Magn Reson Med 61:136–144, 2009. © 2008 Wiley‐Liss, Inc.
Aortic vessel wall magnetic resonance imaging at 3.0 Tesla: A reproducibility study of respiratory navigator gated free‐breathing 3D black blood magnetic resonance imaging
Authors: Roes Stijntje D. , Westenberg Jos J.M. , Doornbos Joost , van der Geest Rob J. , Angelié Emmanuelle , de Roos Albert , Stuber Matthias 
Published: December 2008

AbstractThe purpose of this study was to evaluate a free‐breathing three‐dimensional (3D) dual inversion‐recovery (DIR) segmented k‐space gradient‐echo (turbo field echo [TFE]) imaging sequence at 3T for the quantification of aortic vessel wall dimensions. The effect of respiratory motion suppression on image quality was tested. Furthermore, the reproducibility of the aortic vessel wall measurements was investigated. Seven healthy subjects underwent 3D DIR TFE imaging of the aortic vessel wall with and without respiratory navigator. Subsequently, this sequence with respiratory navigator was performed twice in 10 healthy subjects to test its reproducibility. The signal‐to‐noise (SNR), contrast‐to‐noise ratio (CNR), vessel wall sharpness, and vessel wall volume (VWV) were assessed. Data were compared using the paired t‐test, and the reproducibility of VWV measurements was evaluated using intraclass correlation coefficients (ICCs). SNR, CNR, and vessel wall sharpness were superior in scans performed with respiratory navigator compared to scans performed without. The ICCs concerning intraobserver, interobserver, and interscan reproducibility were excellent (0.99, 0.94, and 0.95, respectively). In conclusion, respiratory motion suppression substantially improves image quality of 3D DIR TFE imaging of the aortic vessel wall at 3T. Furthermore, this optimized technique with respiratory motion suppression enables assessment of aortic vessel wall dimensions with high reproducibility. Magn Reson Med 61:35–44, 2009. © 2008 Wiley‐Liss, Inc.
Regularized sensitivity encoding (SENSE) reconstruction using bregman iterations
Authors: Liu Bo , King Kevin , Steckner Michael , Xie Jun , Sheng Jinhua , Ying Leslie 
Published: December 2008

AbstractIn parallel imaging, the signal‐to‐noise ratio (SNR) of sensitivity encoding (SENSE) reconstruction is usually degraded by the ill‐conditioning problem, which becomes especially serious at large acceleration factors. Existing regularization methods have been shown to alleviate the problem. However, they usually suffer from image artifacts at high acceleration factors due to the large data inconsistency resulting from heavy regularization. In this paper, we propose Bregman iteration for SENSE regularization. Unlike the existing regularization methods where the regularization function is fixed, the method adaptively updates the regularization function using the Bregman distance at different iterations, such that the iteration gradually removes the aliasing artifacts and recovers fine structures before the noise finally comes back. With a discrepancy principle as the stopping criterion, our results demonstrate that the reconstructed image using Bregman iteration preserves both sharp edges lost in Tikhonov regularization and fines structures missed in total variation (TV) regularization, while reducing more noise and aliasing artifacts. Magn Reson Med 61:145–152, 2009. © 2008 Wiley‐Liss, Inc.
3D cine displacement‐encoded MRI of pulsatile brain motion
Authors: Soellinger Michaela , Rutz Andrea K. , Kozerke Sebastian , Boesiger Peter 
Published: December 2008

AbstractPulsatile brain motion is considered to be an important mechanical link between blood and cerebrospinal fluid (CSF) dynamics. Like many severe brain diseases, different types of hydrocephalus are associated with impairment of these dynamics. In this work a cine displacement‐encoded imaging method employing stimulated echoes (DENSE) and a three‐dimensional (3D) segmented echo‐planar imaging (EPI) readout for brain motion measurements in all three spatial directions is presented. Displacement‐encoded data sets of 12 healthy volunteers were analyzed with respect to reproducibility, periodicity, and intra‐ as well as intersubject physiological consistency. In addition, displacement values were compared with data derived from phase‐contrast (PC) velocity measurements in a subset of all measured subjects. Using DENSE, displacements as low as 0.01 mm could be detected and observation of the 3D pulse pressure wave propagation was possible. Among other parameters, peak displacements in the central brain regions were measured: feet–head (FH): thalamus (0.13 ± 0.01 mm); right–left (RL): thalamus (0.06 ± 0.01 mm); and anterior–posterior (AP): caudate nucleus (0.05 ± 0.01 mm). Magn Reson Med 61:153–162, 2009. © 2008 Wiley‐Liss, Inc.
Functional brain mapping at 9.4T using a new MRI‐compatible electrode chronically implanted in rats
Authors: Dunn Jeff F. , Tuor Ursula I. , Kmech Jonn , Young Nicole A. , Henderson Amy K. , Jackson Jesse C. , Valentine Pamela A. , Teskey G. Campbell 
Published: December 2008

AbstractThere is a need for acute and chronic stimulation of the brain within the MRI for studies of epilepsy, as well as deep brain stimulation for movement and behavioral disorders. This work describes the production and characteristics of carbon fiber–based electrodes for acute and chronic stimulation in the brain. Increasing MRI field strengths are making it increasingly difficult to introduce foreign objects without a susceptibility artifact. We describe the production of, and the characteristics of carbon fiber–based electrodes. These are biocompatible and can be implanted for chronic studies. We show the use of these electrodes at 9.4T for studying functional activation. Data are presented showing regional connectivity. Activation not only occurs near the electrode, but at sites distant and often contralateral to the electrode. In addition, there were sites showing strong negative activation to stimulation both with direct stimulation and during a kindling‐associated seizure. Magn Reson Med 61:222–228, 2009. © 2008 Wiley‐Liss, Inc.
A Bayesian hierarchical model for the analysis of a longitudinal dynamic contrast‐enhanced MRI oncology study
Authors: Schmid Volker J. , Whitcher Brandon , Padhani Anwar R. , Taylor N. Jane , Yang Guang‐Zhong 
Published: December 2008

AbstractImaging in clinical oncology trials provides a wealth of information that contributes to the drug development process, especially in early phase studies. This article focuses on kinetic modeling in DCE‐MRI, inspired by mixed‐effects models that are frequently used in the analysis of clinical trials. Instead of summarizing each scanning session as a single kinetic parameter—such as medianktransacross all voxels in the tumor ROI–we propose to analyze all voxel time courses from all scans and across all subjects simultaneously in a single model. The kinetic parameters from the usual nonlinear regression model are decomposed into unique components associated with factors from the longitudinal study; e.g., treatment, patient, and voxel effects. A Bayesian hierarchical model provides the framework to construct a data model, a parameter model, as well as prior distributions. The posterior distribution of the kinetic parameters is estimated using Markov chain Monte Carlo (MCMC) methods. Hypothesis testing at the study level for an overall treatment effect is straightforward and the patient‐ and voxel‐level parameters capture random effects that provide additional information at various levels of resolution to allow a thorough evaluation of the clinical trial. The proposed method is validated with a breast cancer study, where the subjects were imaged before and after two cycles of chemotherapy, demonstrating the clinical potential of this method to longitudinal oncology studies. Magn Reson Med 61:163–174, 2009. © 2008 Wiley‐Liss, Inc.
Inherent fat cancellation in complementary spatial modulation of magnetization
Authors: Fahmy Ahmed S. , Basha Tamer A. , Osman Nael F. 
Published: December 2008

AbstractAn efficient fat suppression method is presented for MR tagging with complementary spatial modulation of magnetization (CSPAMM). In this method, the complementary modulation is applied to the water content of the tissues, while in‐phase modulation is applied to the fat content. Therefore, during image reconstruction, the subtraction of the acquired images increases the tagging contrast of the water while cancels the tagging lines of the fat. Compared with the existing fat suppression techniques, the proposed method allows imaging with higher temporal resolution and shorter echo‐time without increasing the scan time. The feasibility of applying the method on 1.5 Tesla (T) and 3.0T scanners has been tested using MR phantom and human volunteers. Magn Reson Med 61:234–238, 2009. © 2008 Wiley‐Liss, Inc.
Comparison of normal tissue R1 and R modulation by oxygen and carbogen
Authors: O'Connor James P.B. , Naish Josephine H. , Jackson Alan , Waterton John C. , Watson Yvonne , Cheung Sue , Buckley David L. , McGrath Deirdre M. , Buonaccorsi Giovanni A. , Mills Samantha J. , Roberts Caleb , Jayson Gordon C. , Parker Geoff J.M. 
Published: December 2008

AbstractMagnetic resonance imaging has shown promise for evaluating tissue oxygenation. In this study differences in the tissue longitudinal relaxation rate (R1) and effective transverse relaxation rate (R), induced by inhalation of pure oxygen and carbogen, were evaluated in 10 healthy subjects. Significant reductions in R1 were demonstrated following both oxygen and carbogen inhalation in the spleen (both P < 0.001), liver (P = 0.002 air vs. oxygen; P = 0.001 air vs. carbogen), skeletal muscle (both P < 0.001), and renal cortex (P = 0.005 air vs. oxygen; P = 0.008 air vs. carbogen). No significant change in R occurred following pure oxygen in any organ. However, a significant increase in R was observed in the spleen (P < 0.001), liver (P = 0.001), skeletal muscle (P = 0.026), and renal cortex (P = 0.001) following carbogen inhalation, an opposite effect to that observed in many studies of tumor pathophysiology. Changes in R1 and R were independent of the gas administration order in the spleen and skeletal muscle. These findings suggest that the R1 and R responses to hyperoxic gases are independent biomarkers of oxygen physiology. Magn Reson Med 61:75–83, 2009. © 2008 Wiley‐Liss, Inc.