bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved cerebellar tissue classification on magnetic resonance images of brain
Authors: Datta Sushmita , Tao Guozhi , He Renjie , Wolinsky Jerry S. , Narayana Ponnada A. 
Published: April 2009

AbstractPurposeTo develop and implement a method for improved cerebellar tissue classification on the MRI of brain by automatically isolating the cerebellum prior to segmentation.Materials and MethodsDual fast spin echo (FSE) and fluid attenuation inversion recovery (FLAIR) images were acquired on 18 normal volunteers on a 3 T Philips scanner. The cerebellum was isolated from the rest of the brain using a symmetric inverse consistent nonlinear registration of individual brain with the parcellated template. The cerebellum was then separated by masking the anatomical image with individual FLAIR images. Tissues in both the cerebellum and rest of the brain were separately classified using hidden Markov random field (HMRF), a parametric method, and then combined to obtain tissue classification of the whole brain. The proposed method for tissue classification on real MR brain images was evaluated subjectively by two experts. The segmentation results on Brainweb images with varying noise and intensity nonuniformity levels were quantitatively compared with the ground truth by computing the Dice similarity indices.ResultsThe proposed method significantly improved the cerebellar tissue classification on all normal volunteers included in this study without compromising the classification in remaining part of the brain. The average similarity indices for gray matter (GM) and white matter (WM) in the cerebellum are 89.81 (±2.34) and 93.04 (±2.41), demonstrating excellent performance of the proposed methodology.ConclusionThe proposed method significantly improved tissue classification in the cerebellum. The GM was overestimated when segmentation was performed on the whole brain as a single object. J. Magn. Reson. Imaging 2009;29:1035–1042. © 2009 Wiley‐Liss, Inc.
MRI of late microstructural and metabolic alterations in radiation‐induced brain injuries
Authors: Chan Kevin C. , Khong Pek‐lan , Cheung Matthew M. , Wang Silun , Cai Ke‐xia , Wu Ed X. 
Published: April 2009

AbstractPurposeTo evaluate the late effects of radiation‐induced damages in the rat brain by means of in vivo multiparametric MRI.Materials and MethodsThe right hemibrains of seven Sprague‐Dawley rats were irradiated with a highly collimated 6 MV photon beam at a single dose of approximately 28 Gy. Diffusion tensor imaging (DTI), proton MR spectroscopy (1H‐MRS), T2‐weighted imaging, and T1‐weighted imaging were performed to the same animals 12 months after radiation treatment.ResultsCompared with the contralateral side, a significantly higher percentage decrease in fractional anisotropy was observed in the ipsilateral fimbria of hippocampus (29%) than the external capsule (8%) in DTI, indicating the selective vulnerability of fimbria to radiation treatment. Furthermore, in1H‐MRS, significantly higher choline, glutamate, lactate, and taurine peaks by 24%, 25%, 87%, and 58%, respectively, were observed relative to creatine in the ipsilateral brain. Postmortem histology confirmed these white matter degradations as well as glial fibrillary acidic protein and glutamine synthetase immunoreactivity increase in the ipsilateral brain.ConclusionThe microstructural and metabolic changes in late radiation‐induced brain injuries were documented in vivo. These multiparametric MRI measurements may help understand the white matter changes and neurotoxicity upon radiation treatment in a single setting. J. Magn. Reson. Imaging 2009;29:1013–1020. © 2009 Wiley‐Liss, Inc.
Microperfusion‐induced elevation of ADC is suppressed after contrast in breast carcinoma
Authors: Yuen Sachiko , Yamada Kei , Goto Mariko , Nishida Kaori , Takahata Akiko , Nishimura Tsunehiko 
Published: April 2009

AbstractPurposeTo investigate the effect of gadolinium (Gd)‐DTPA on the apparent diffusion coefficient (ADC) of breast carcinoma and to analyze the relationship between pre/postcontrast ADC and the degree of contrast enhancement.Materials and MethodsNineteen histopathologically confirmed breast carcinomas (mean size = 22 mm) were analyzed. Their ADCs before and after contrast administration were measured. The contrast‐to‐noise ratios (CNRs) of the tumors were measured on fat‐suppressed 3D T1‐weighted images in precontrast, early, and late postcontrast phases. These results were correlated with the measured ADC values.ResultsA significant decrease in the measured ADC was noted after contrast administration (−23%, P = 0.01). Lesions with relatively high ADC before contrast (>1.3 × 10−3 mm2/sec; n = 12) demonstrated a larger degree of ADC reduction (mean 34%) than lesions with low ADC (≤1.3 × 10−3 mm2/sec; n = 7) (mean 4.5%). When an early postcontrast image was used as a surrogate marker of malignant potential, we found a significant inverse correlation with postcontrast ADC (γ = −0.57, P = 0.02).ConclusionPostcontrast ADC exhibited lower values than precontrast ADC, which is thought to reflect suppression of the microperfusion‐induced effect on diffusion‐weighted imaging. Postcontrast ADC may be a better indicator than precontrast ADC to reflect malignant potential of tumors. J. Magn. Reson. Imaging 2009;29:1080–1084. © 2009 Wiley‐Liss, Inc.
Fast dixon‐based multisequence and multiplanar MRI for whole‐body detection of cancer metastases
Authors: Ma Jingfei , Costelloe Colleen M. , Madewell John E. , Hortobagyi Gabriel N. , Green Marjorie C. , Cao Guang , Sun Fei , Kundra Vikas 
Published: April 2009

AbstractPurposeTo develop and demonstrate the feasibility of multisequence and multiplanar MRI for whole‐body cancer detection.Materials and MethodsTwo fast Dixon‐based sequences and a diffusion‐weighted sequence were used on a commercially available 1.5 T scanner for whole‐body cancer detection. The study enrolled 19 breast cancer patients with known metastases and in multistations acquired whole‐body axial diffusion‐weighted, coronal T2‐weighted, axial/sagittal pre‐ and postcontrast T1‐weighted, as well as triphasic abdomen images. Three radiologists subjectively scored Dixon images of each series for overall image quality and fat suppression uniformity on a 4‐point scale (1 = poor, 2 = fair, 3 = good, and 4 = excellent).ResultsEighteen of the 19 patients completed the whole‐body MRI successfully. The mean acquisition time and overall patient table time were 46 ± 3 and 69 ± 5 minutes, respectively. The average radiologists' scores for overall image quality and fat suppression uniformity were both 3.4 ± 0.5. The image quality was consistent between patients and all completed whole‐body examinations were diagnostically adequate.ConclusionWhole‐body MRI offering essentially all the most optimal tumor‐imaging sequences in a typical 1‐hour time slot can potentially become an appealing “one‐stop‐shop” for whole‐body cancer imaging. J. Magn. Reson. Imaging 2009;29:1154–1162. © 2009 Wiley‐Liss, Inc.
MRI features of cellular angiomyofibroma with pathologic correlation
Authors: Koo Phillip J. , Goykhman Igor , Lembert Larissa , Nunes Linda W. 
Published: April 2009

AbstractWithin the spectrum of extratesticular mesenchymal tumors in the scrotum and perineum lies cellular angiofibroma, also known as angiomyofibroblastoma‐like tumor, a rare lesion originally described to almost exclusively occur in the vulva, perineum, and pelvis of women. We report a case of this tumor, with an adjacent scrotal lipoma, occurring in a 60‐year‐old male who presented to our department with a firm palpable scrotal mass. To our knowledge, the MRI findings of this entity have yet to be described in the radiological literature. We present the MRI features of cellular angiofibroma that are consistent with the pathological characteristics of this entity—a benign cellular and fibrous tumor with prominent vascularity. J. Magn. Reson. Imaging 2009;29:1195–1198. © 2009 Wiley‐Liss, Inc.
Image artifacts in concurrent transcranial magnetic stimulation (TMS) and fMRI caused by leakage currents: Modeling and compensation
Authors: Weiskopf Nikolaus , Josephs Oliver , Ruff Christian C. , Blankenburg Felix , Featherstone Eric , Thomas Anthony , Bestmann Sven , Driver Jon , Deichmann Ralf 
Published: April 2009

AbstractPurposeTo characterize and eliminate a new type of image artifact in concurrent transcranial magnetic stimulation and functional MRI (TMS‐fMRI) caused by small leakage currents originating from the high‐voltage capacitors in the TMS stimulator system.Materials and MethodsThe artifacts in echo‐planar images (EPI) caused by leakage currents were characterized and quantified in numerical simulations and phantom studies with different phantom‐coil geometries. A relay‐diode combination was devised and inserted in the TMS circuit that shorts the leakage current. Its effectiveness for artifact reduction was assessed in a phantom scan resembling a realistic TMS‐fMRI experiment.ResultsThe leakage‐current‐induced signal changes exhibited a multipolar spatial pattern and the maxima exceeded 1% at realistic coil‐cortex distances. The relay‐diode combination effectively reduced the artifact to a negligible level.ConclusionThe leakage‐current artifacts potentially obscure effects of interest or lead to false‐positives. Since the artifact depends on the experimental setup and design (eg, amplitude of the leakage current, coil orientation, paradigm, EPI parameters), we recommend its assessment for each experiment. The relay‐diode combination can eliminate the artifacts if necessary. J. Magn. Reson. Imaging 2009;29:1211–1217. © 2009 Wiley‐Liss, Inc.
Non‐contrast‐enhanced MR portography with time‐spatial labeling inversion pulses: Comparison of imaging with three‐dimensional half‐fourier fast spin‐echo and true steady‐state free‐precession sequences
Authors: Shimada Kotaro , Isoda Hiroyoshi , Okada Tomohisa , Kamae Toshikazu , Arizono Shigeki , Hirokawa Yuusuke , Shibata Toshiya , Togashi Kaori 
Published: April 2009

AbstractPurposeTo compare and evaluate images acquired with two different MR angiography (MRA) sequences, three‐dimensional (3D) half‐Fourier fast spin‐echo (FSE) and 3D true steady‐state free‐precession (SSFP) combined with two time‐spatial labeling inversion pulses (T‐SLIPs), for selective and non‐contrast‐enhanced (non‐CE) visualization of the portal vein.Materials and MethodsTwenty healthy volunteers were examined using half‐Fourier FSE and true SSFP sequences on a 1.5T MRI system with two T‐SLIPs, one placed on the liver and thorax, and the other on the lower abdomen. For quantitative analysis, vessel‐to‐liver contrast (Cv‐l) ratios of the main portal vein (MPV), right portal vein (RPV), and left portal vein (LPV) were measured. The quality of visualization was also evaluated.ResultsIn both pulse sequences, selective visualization of the portal vein was successfully conducted in all 20 volunteers. Quantitative evaluation showed significantly better Cv‐l at the RPVs and LPVs in half‐Fourier FSE (P < 0.0001). At the MPV, Cv‐l was better in true SSFP, but was not statistically different. Visualization scores were significantly better only at branches of segments four and eight for half‐Fourier FSE (P = 0.001 and 0.03, respectively).ConclusionBoth 3D half‐Fourier FSE and true SSFP scans with T‐SLIPs enabled selective non‐CE visualization of the portal vein. Half‐Fourier FSE was considered appropriate for intrahepatic portal vein visualization, and true SSFP may be preferable when visualization of the MPV is required. J. Magn. Reson. Imaging 2009;29:1140–1146. © 2009 Wiley‐Liss, Inc.
Diminished visibility of cerebral venous vasculature in multiple sclerosis by susceptibility‐weighted imaging at 3.0 Tesla
Authors: Ge Yulin , Zohrabian Vahe M. , Osa Etin‐Osa , Xu Jian , Jaggi Hina , Herbert Joseph , Haacke E. Mark , Grossman Robert I. 
Published: April 2009

AbstractMultiple sclerosis (MS) is a disease of the central nervous system characterized by widespread demyelination, axonal loss and gliosis, and neurodegeneration; susceptibility‐weighted imaging (SWI), through the use of phase information to enhance local susceptibility or T2* contrast, is a relatively new and simple MRI application that can directly image cerebral veins by exploiting venous blood oxygenation. Here, we use high‐field SWI at 3.0 Tesla to image 15 patients with clinically definite relapsing‐remitting MS and to assess cerebral venous oxygen level changes. We demonstrate significantly reduced visibility of periventricular white matter venous vasculature in patients as compared to control subjects, supporting the concept of a widespread hypometabolic MS disease process. SWI may afford a noninvasive and relatively simple method to assess venous oxygen saturation so as to closely monitor disease severity, progression, and response to therapy. J. Magn. Reson. Imaging 2009;29:1190–1194. © 2009 Wiley‐Liss, Inc.
Improved vessel delineation in keyhole time‐resolved contrast‐enhanced MR angiography using a gadolinium doped flush
Authors: Beranek‐Chiu Jan , Froehlich John M. , Wentz Klaus U. , Doert Alexis N. , Zollikofer Christoph L. , Eckhardt Boris P. 
Published: April 2009

AbstractPurposeTo prospectively assess the influence of a gadolinium doped saline flush compared with a pure saline flush on the image quality of the supra‐aortic vessels using time‐resolved contrast‐enhanced MR angiography (4D CE‐MRA) in a randomized double blind clinical trial.Materials and MethodsTwenty‐two patients scheduled for contrast‐enhanced craniocerebral MRI underwent a supplemental 4D CE‐MRA covering the carotids to the superior sinus consisting of 30 dynamics of a T1‐weighted 3D gradient‐echo sequence (FFE) in sagittal direction. The temporal resolution of 1.1 s per dataset was achieved using the keyhole technique with the reference scan acquired at the end. Immediately after the intravenous (IV) injection of 0.1 mmol Gd/kg body weight of gadoterate, our patients received a 50‐mL flush consisting either of a 0.9% saline solution (n = 11) or doped with 50 mM gadolinium (n = 11; total Gd: 0.11 mmol/kg) at a flow‐rate of 2 mL/s. Vessel delineation, image quality, signal‐to‐noise‐ (SNR) and contrast‐to‐noise (CNR) ratios over time were compared.ResultsBoth vessel delineation (internal carotid artery [ICA]: slopesaline = 308.5; slopeGd = 528.9; P = 0.006; superior sagittal sinus [SSS]: slopesaline = 505.3; slopeGd = 674.9; P = 0.007) and CNR (ICA: CNRsaline = 57.3; CNRGd = 80.55; P = 0.0417; SSS: CNRsaline = 74.15; CNRGd = 117.4; P = 0.0331) of the ICA and SSS were significantly increased using the gadolinium doped flush.ConclusionA low concentrated gadolinium flush in comparison to a pure saline flush improves significantly vessel contrast and their delineation in time‐resolved CE‐MRA using the keyhole technique. J. Magn. Reson. Imaging 2009;29:1147–1153. © 2009 Wiley‐Liss, Inc.
Climate and weather factors modulating river flows in southern Angola
Authors: Jury Mark 
Published: April 2009

AbstractThe large‐scale circulation and thermodynamic fields that modulate the flow of the Kavango River in southern Angola during austral summer are studied. According to composite patterns constructed from National Center for Environmental Prediction (NCEP) data, enhanced river flow is associated with an anomalous wave train of upper level winds that emanate from the North Atlantic. Sea‐surface temperatures (SST) show a warm‐north/cool‐south Atlantic dipole condition as the Kavango River rises. Correlations are analysed with respect to the Kavango River flow and a 0 lag value of − 0.41 is found for the upper zonal wind over the North Atlantic. Rainfall over the African Sahel region is positively linked with Kavango River flow at 6 month lead time (r = + 0.34). The work is extended to the event scale and it is found that winds draw tropical moisture over southern Angola in response to an anomalous low‐high pair and bifurcated subtropical jet stream. A continental scale sea breeze circulation amplifies the convection during afternoons. Knowledge of run‐off into Namibia is critical to the management and planning of water resources in the northern Kalahari savanna. Copyright © 2009 Royal Meteorological Society
Real‐time molecular assessment on oxidative injury of single cells using Raman spectroscopy
Authors: Chang Wei‐Tien , Lin Hung‐Lung , Chen Hung‐Che , Wu Yao‐Ming , Chen Wen‐Jone , Lee Yuan‐Teh , Liau Ian 
Published: April 2009

AbstractOxidative stress is encountered in many biological systems; the resultant oxidative injury plays a significant role in the pathogenesis of diverse diseases. Conventional measurements on oxidative injury are employed almost exclusively on a large population of cells either by counting the fraction of cell death or by observing the fluorometric change resulting from exogenous reagents, thereby lacking in molecular detail and temporal specificity. In this work we combine laser tweezers and Raman spectroscopy to observe the response of single cells to oxidative stress. By measuring the temporal changes of vibrational spectra of single optically trapped cells, we demonstrate a molecular‐level assessment of cellular oxidative injury in real time, both qualitatively and quantitatively, without the introduction of exogenous reagents. The main experimental findings are supported by the observation of Raman spectra of intermediates and downstream products. The abrogation of the above changes by ascorbic acid further illustrates the therapeutic effect of antioxidants against cellular oxidative injury. This approach is extensible to studies exploring the biochemical transformation of single cells or intracellular organelles in response to various chemical or physical stimuli. With the aid of ‘molecular fingerprints’, single‐cell Raman spectroscopy exhibits a great potential for accessing the chemical aspects of cellular bioactivity, yielding insight into pathophysiological processes and assisting the development of novel therapeutic interventions against diseases. Copyright © 2009 John Wiley & Sons, Ltd.
Combined use of HMF and furosine to assess fresh honey quality
Authors: Morales Valle , Sanz María Luz , Martín‐Álvarez Pedro J , Corzo Nieves 
Published: April 2009

AbstractBACKGROUND: The quality of honey can be affected by practices such as adulteration, inadequate storage or the application of severe heat treatments. Because hydroxymehylfurfural (HMF) is an indicator of honey freshness and furosine (ε‐2‐furoylmethyl lysine) has proved to be a useful chemical indicator of the progress of the Maillard reaction in foods, the aim of this work was to assess their usefulness as indicators of fresh honey quality. The effect of heat treatment, storage and adulteration with different types of syrups on HMF and furosine content has been studied.RESULTS: In fresh honey, HMF and furosine values ranged from 0.9 to 14.6 mg kg−1 of product and from 3.06 to 12.06 g kg−1 of protein, respectively. Heating of honey samples with different pH (3.76 and 5.14) produced slight increases in HMF content and negligible changes were detected in furosine values. The storage of fresh honey for 2 years caused a high increase in the HMF level, reaching values above EU limits. However, furosine showed a different behavior depending on the type of honey sample. Adulteration assays using different syrups produced an increase in HMF and a decrease of furosine values by dilution effect. HMF content of adulterated honey samples with syrup of known origin did not exceed EU limits.CONCLUSION: These results show the influence of long periods of storage or adulteration, using different percentages of corn or invert sugar syrups, on HMF and furosine content of fresh honey. This seems to indicate that the combination of HMF and furosine may be useful for evaluating the quality of fresh honey. Copyright © 2009 Society of Chemical Industry
Theoretical study of the O + HSO reaction
Authors: Ballester M. Y. , Varandas A. J. C. 
Published: April 2009

AbstractA quasi‐classical trajectory study of the title reaction is reported using a global, double, many‐body expansion potential energy surface for HSO2. Calculations are presented for specific translational energies and rovibrational states of the reactants, showing that formations of H + SO2 and HS + O2 are the most favored processes, although other products are also formed. The reaction is predicted to be barrier free and its mechanism is discussed, with reaction rate constants also being reported. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 455–462, 2009
Self‐organized colloidal crystals for photonics and laser applications
Authors: Furumi S. , Fudouzi H. , Sawada T. 
Published: April 2009

AbstractWe present an overview of recent developments in the fabrication and uses of colloidal crystals (CCs) for photonics and laser applications. Microparticles with a diameter in the range from 10 nm to 10 μm often have an intrinsic capability to spontaneously organize themselves from a colloidal suspension into 3D lattice structures. Such highly ordered 3D architectures of microparticles are called colloidal crystals (CCs). The CC structures have received tremendous attention as one of the facile and high‐throughput fabrication techniques of photonic crystals (PCs). We introduce here interesting precedents not only of diverse techniques of high‐quality CC structures, but also of their versatile applications in optical sensors responding to various external stimuli. This review also highlights a new potential use of the CCs as low‐threshold laser devices. We believe that a wide variety of CC architectures will play leading roles in the next generation of optoelectronic devices.
Synthesis of PVP‐coated silver nanoparticles and their biological activity towards human mesenchymal stem cells
Authors: Kittler S. , Greulich C. , Köller M. , Epple M. 
Published: April 2009

AbstractSilver nanoparticles were prepared by the polyol process, i.e. by the reduction of silver nitrate with ethylene glycol in the presence of polyvinylpyrrolidone, PVP. Thereby, the silver nanoparticles were colloidally stabilized by the polymer. The synthesis of nanoparticles of different size and shape (cubes, rods and spheres) was possible by changing the reaction conditions such as reagent ratio and temperature. The silver nanoparticles were characterized by dynamic light scattering (DLS), zeta‐potential measurements, UV‐spectroscopy, and scanning electron microscopy (SEM). The biological activity of spherical PVP‐coated silver nanoparticles (about 100 nm diameter) was tested on human mesenchymal stem cells (hMSC) in comparison with equivalent amounts of silver ions (silver acetate). hMSC were treated with silver concentrations in the range of 50 ng mL‐1 to 50 μg mL‐1 for 7 days under cell culture conditions. Cytotoxic cell reactions occurred at ≥2.5 μg Ag mL‐1 for nanoparticles and ≥1 μg Ag mL‐1 for silver acetate, indicating a critical role of the silver ions for toxic reactions.