bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of neuroimaging in promoting long‐term recovery from ischemic stroke
Authors: Seitz Rüdiger J. , Donnan Geoffrey A. 
Published: September 2010

AbstractHuman ischemic stroke is an acute disorder followed by a recovery period which may be of varying duration and mechanism. Imaging has created a means to explore the stroke process in vivo, particularly its underlying pathophysiology and recovery mechanisms. Evidence from multicenter studies has shown that, in the acute phase, arterial recanalization and reperfusion of ischemic brain tissue are the most important determinants of recovery. This is followed by functional and structural changes in the perilesional tissue and in large‐scale bihemispheric networks that continue with different dynamics for weeks to months. Proof‐of‐principle studies have revealed that the behavioral gains induced by rehabilitation are paralleled by changes in functional representations. This is supported by data from neuroimaging and electrophysiological studies early after stroke which have shown that dedicated training can induce changes in cerebral functional representations. Accordingly, there is clear evidence that neuroimaging has a significant potential for monitoring the hemodynamic, functional, and structural factors determining recovery from stroke. New imaging methods may provide relevant biomarkers for treatment decisions and therapeutic monitoring. By combining neuroimaging with electrophysiological measures, opportunities exist to develop neuroscience‐based strategies in rehabilitation. J. Magn. Reson. Imaging 2010;32:756–772. © 2010 Wiley‐Liss, Inc.
Characterization of cirrhotic nodules with gadoxetic acid‐enhanced magnetic resonance imaging: The efficacy of hepatocyte‐phase imaging
Authors: Chou Chen‐Te , Chen Yao‐Li , Su Wei‐Wen , Wu Hwa‐Koon , Chen Ran‐Chou 
Published: September 2010

AbstractPurposeTo evaluate the efficacy of hepatocyte‐phase imaging (HP) in characterization of focal hepatic lesions in cirrhotic liver using gadoxetic acid‐enhanced magnetic resonance imaging (MRI).MethodsA total of 66 nodules of 38 patients with liver cirrhosis undergoing gadoxetic acid‐enhanced MRI were prospectively enrolled in this study. The histological examination revealed 15 dysplastic nodules (DNs), 7 well‐differentiated hepatocellular carcinomas (wHCCs), and 44 moderately differentiated HCCs (mHCCs). Two imaging sets (Set A without HP, Set B with HP) were prepared to evaluate the efficacy of HP in lesion characterization.ResultsThe mean enhancement ratios (ERs) of mHCC were significantly increased in arterial phase followed by a subsequent decreased in hepatocyte phases. The mean ERs of wHCC were increased in dynamic study and followed by a plateau in the hepatocyte phase. The mean ERs of DNs were increased in dynamic study and hepatocyte phase. The mean liver‐to‐lesion contrasts of mHCCs were increased in arterial phase and HP (P < 0.05). wHCCs were only increased in HP (P < 0.05). DNs showed no significant difference in any phase (P > 0.05). There were seven additional HCCs that were detected in HP using imaging Set B compared to Set A. The diagnostic performance of Set B was significantly higher than that of Set A (P = 0.016).ConclusionThe combination of gadoxetic acid‐enhanced dynamic study and hepatocyte‐phase T1WI may provide better diagnostic performance than only dynamic study in characterization of focal lesions in cirrhotic liver. J. Magn. Reson. Imaging 2010;32:895–902. © 2010 Wiley‐Liss, Inc.
Measurement of gas transport kinetics in high‐frequency oscillatory ventilation (HFOV) of the lung using hyperpolarized 3He magnetic resonance imaging
Authors: Terekhov Maxim , Rivoire Julien , Scholz Alexander , Wolf Ursula , Karpuk Sergei , Salhi Zahir , Koebrich Rainer , David Matthias , Schreiber Laura Maria 
Published: September 2010

AbstractPurposeTo protect the patient with acute respiratory distress syndrome from ventilator associated lung injury (VALI) high‐frequency oscillatory ventilation (HFOV) is used. Clinical experience has proven that HFOV is an efficient therapy when conventional artificial ventilation is insufficient. However, the optimal settings of HFOV parameters, eg, tidal volumes, pressure amplitudes and frequency for maximal lung protection, and efficient gas exchange are not established unambiguously.MethodsIn this work magnetic resonance imaging (MRI) with hyperpolarized 3He was employed to visualize the redistribution of gas within the cadaver pig lung during HFOV. The saturated slice method was used to characterize fast gas kinetics.ResultsThe strong differences in kinetics were observed for HFOV‐driven gas exchange in comparison with diffusive gas transport (apnea). The significant regional and HFOV frequency dependence was detected for washout and gas exchange within the lungs. Gas redistribution was much faster in posterior than in anterior parts of the lungs during HFOV, in contrast to minor differences with an opposite trend observed in apnea.ConclusionThe method shows significant potential for visualization and quantification of gas redistribution under HFOV and may help in optimization of the parameters to improve the clinical effect of HFOV for patients. J. Magn. Reson. Imaging 2010;32:887–894. © 2010 Wiley‐Liss, Inc.
Diffusion tensor tractography demonstration of partially injured spinal cord tracts in a patient with posttraumatic brown sequard syndrome
Authors: Rajasekaran Shanmughanathan , Kanna Rishi Mugesh , Karunanithi Rajamanickam , Shetty Ajoy Prasad 
Published: September 2010

AbstractThe authors report the utility of diffusion tensor tractography in demonstrating the partially severed spinal cord tracts on one side with normal, intact, distally traceable tracts on the opposite side in a patient with posttraumatic Brown Sequard syndrome. A 30‐year‐old man presented with typical clinical features of a hemisection injury of the thoracic spinal cord, 2 months after he had sustained a back stab injury. Routine MRI showed T2 hyperintense zones in the thoracic spinal cord at the level of T5. We did axial single shot echo planar diffusion tensor imaging with a 1.5 Tesla MR machine. Tractography effectively depicted the injured spinal cord tracts on the left side with normal intact tracts on the right side, which could be traced distally. The fractional anisotropy and apparent diffusion coefficient values showed significant changes at the level of injury. Tractographic demonstration of human spinal cord injury is reported for the first time. J. Magn. Reson. Imaging 2010;32:978–981. © 2010 Wiley‐Liss, Inc.
Dynamic susceptibility contrast perfusion weighted imaging in grading of nonenhancing astrocytomas
Authors: Morita Naomi , Wang Sumei , Chawla Sanjeev , Poptani Harish , Melhem Elias R. 
Published: September 2010

AbstractPurposeTo evaluate if the relative tumor blood volume (rTBV) using dynamic susceptibility contrast magnetic resonance imaging (DSC‐MRI) can aid in distinguishing low‐ from high‐grade nonenhancing astrocytomas.Materials and MethodsSeventeen patients with histologically proven astrocytomas underwent MRI including DSC‐MRI. Maximum TBV regions of interest were recorded from each neoplasm and normalized to contralateral normal white matter. Demographic features, diagnostic MRI findings including tumor volumes, and the normalized rTBV ratios were compared between low‐grade (I and II, LGA, n = 6) and high‐grade (III) astrocytomas (HGA, n = 11) using Mann–Whitney's U‐test and receiver operating characteristic (ROC) analysis.ResultsMaximum rTBV ratios were statistically higher for HGA (1.11 ± 0.13) than LGA (0.66 ± 0.17, P < 0.005) with the best cutoff threshold at 0.94 (sensitivity of 90.9%, specificity of 100%). Differences in mean age and tumor volume on fluid‐attenuated inversion recovery (FLAIR) imaging between the two groups did not reach statistical difference (P = 0.22, 0.36).ConclusionThe addition of DSC‐MRI can aid in accurate grading of nonenhancing astrocytomas with high sensitivity and specificity. J. Magn. Reson. Imaging 2010;32:803–808. © 2010 Wiley‐Liss, Inc.
Late gadolinium enhancement of acute myocardial infarction in mice at 7T: Cine‐FLASH versus inversion recovery
Authors: Protti Andrea , Sirker Alexander , Shah Ajay M. , Botnar Rene 
Published: September 2010

AbstractPurposeTo investigate myocardial infarction (MI), late gadolinium (Gd) enhancement (LGE), cardiovascular magnetic resonance imaging (CMRI) is used as the current gold standard for the in vivo diagnosis in patients and preclinical studies. While inversion recovery (IR) fast gradient echo LGE imaging is the preferred technique at clinical field strengths it remains to be investigated which is the best sequence at higher field strength. We therefore compared the IR technique against cine fast low shot angle (cine‐FLASH) for the quantification of MI size in mice at 7T in vivo.Materials and MethodsFive mice were used to optimize cine‐FLASH and IR parameters. Nine mice were subsequently imaged with optimized parameters using both techniques 2–3 days after MI and ≈30 minutes post Gd injection.ResultsThe difference in infarct size values was within 3.3% between the two CMRI techniques and within 7.5% of histological values by Bland–Altman analysis. Contrast‐to‐noise‐ratio between infarcted and normal tissue as well as blood was higher for cine‐FLASH with the additional benefit of a 2‐time‐fold shorter scan time than with the IR method. Furthermore, left ventricular function/volumes could be calculated from cine‐FLASH images before as well as after Gd injection.ConclusionIn conclusion, cine‐FLASH LGE MRI represents an attractive alternative to IR LGE MRI for infarct size assessment in mice at high field strengths because it provides similar accuracy while being more robust, faster, and less user dependent. J. Magn. Reson. Imaging 2010;32:878–886. © 2010 Wiley‐Liss, Inc.
Mixed‐bandwidth acquisitions: Signal‐to‐noise ratio and signal‐to‐noise efficiency
Authors: Choli Morwan , Jakob Peter M. , Loeffler Ralf B. , Hillenbrand Claudia M. 
Published: September 2010

AbstractPurposeTo evaluate signal‐to‐noise ratio (SNR) and SNR efficiency in mixed‐bandwidth acquisition (MBA). SNR efficiency describes the achievable SNR per unit time and is a basic aspect in clinical applications to optimize work flow.Materials and MethodsCorresponding simulations were performed and predictions of the theory verified in phantom experiments and volunteers. Specifically, SNR and SNR efficiencies were compared for an MBA fast low‐angle shot (MBA‐FLASH) sequence and traditional single‐bandwidth acquisitions.Results:MBAs result in an SNR penalty compared to single‐bandwidth acquisitions for a given sampling time. Furthermore, the nonuniform distribution of noise characteristics in k‐space introduced by MBA sequences caused potential changes in noise texture of the image.ConclusionOverall, the MBA‐FLASH imaging experiments in phantoms and healthy volunteers support the feasibility of using dual or multiple bandwidth acquisitions, which may be important in alternative imaging schemes that combine multiple acquisition techniques. J. Magn. Reson. Imaging 2010;32:997–1002. © 2010 Wiley‐Liss, Inc.
Diffusion tensor tractography of the human brain cortico‐ponto‐cerebellar pathways: A quantitative preliminary study
Authors: Kamali Arash , Kramer Larry A. , Frye Richard E. , Butler Ian J , Hasan Khader M. 
Published: September 2010

AbstractPurposeTo investigate the utility of diffusion tensor tractography at 1mm slice thickness to map and quantify the whole trajectory of different cortico‐ponto‐cerebellar pathways of the healthy adult human brain.Materials and MethodsThis work was approved by the local Institutional Review Board, and was Health Insurance Portability and Accountability Act (HIPAA) compliant. Five healthy right‐handed men (age range, 24–37 years) were studied and written informed consent was obtained. Diffusion tensor imaging data acquired with 1‐mm slice thickness at a 3.0 Tesla (T) clinical MRI scanner were prepared and analyzed using tractography methods to reconstruct the cortico‐ponto‐cerebellar pathways which included the fronto‐ponto‐cerebellar, parieto‐ponto‐cerebellar, occipito‐ponto‐cerebellar, and temporo‐ponto‐cerebellar tracts.ResultsWe demonstrate the feasibility of tractographic mapping and quantification of the four cortico‐ponto‐cerebellar system components based on their cortical connections in the healthy human brain using DTI data with thin 1‐mm sections.ConclusionIn vivo quantification of different cortico‐ponto‐cerebellar pathways based on cortical connection is feasible, using 1‐mm slices at 3.0T. J. Magn. Reson. Imaging 2010;32:809–817. © 2010 Wiley‐Liss, Inc.
Comparison of enhancement patterns of histologically confirmed hepatocellular carcinoma between gadoxetate‐ and ferucarbotran‐enhanced magnetic resonance imaging
Authors: Okada Masahiro , Imai Yasuharu , Kim Tonsok , Kogita Sachiyo , Takamura Manabu , Kumano Seishi , Onishi Hiromitsu , Hori Masatoshi , Fukuda Kazuto , Hayashi Norio , Wakasa Kenichi , Sakamoto Michiie , Murakami Takamichi 
Published: September 2010

AbstractPurposeTo compare enhancenent patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) between gadoxetate‐ and ferucarbotran‐enhanced MRI.Materials and MethodsPatients recruited from ultrasound surveillance for HCC in chronic liver diseases were enrolled in this prospective study approved by institutional review board. Thirty‐six patients with 37 histologically proven HCC, including 22 well‐differentiated HCCs (wHCC), 15 moderately to poorly differentiated HCCs (mpHCCs), and 4 DNs, underwent gadoxetate‐enhanced and ferucarbotran‐enhanced MRI. We compared hepatobiliary phase image of gadoxetate‐enhanced MRI with ferucarbotran‐enhanced MR image regarding signal intensity of HCC and DN relative to surrounding liver parenchyma. We calculated contrast ratios between tumor and liver on pre‐enhancement, hepatobiliary phase of gadoxetate‐enhanced MRI and ferucarbotran‐enhanced MRI.ResultsOn ferucarbotran‐enhanced MRI, all mpHCCs showed hyper‐intensity, while 14 wHCCs (14/22;63%) showed iso‐intensity. On hepatobiliary phase of gadoxetate‐enhanced MRI, 13 mpHCCs (13/15;86%) and 20 wHCCs (20/22;91%) showed hypo‐intensity. Two DNs and the other two showed iso‐ and hypo‐intensity, respectively, on gadoxetate‐enhanced MRI, whereas all DNs revealed iso‐intensity on ferucarbotran‐enhanced MRI. Gadoxetate‐postcontrast ratio was significantly lower than ferucarbotran‐postcontrast ratio in wHCC (P = 0.015).ConclusionThe uptake function of hepatocytes that are targeted by gadoxetate is more sensitive than that of Kupffer cells targeted by ferucarbotran in stepwise hepatocarcinogenesis. J. Magn. Reson. Imaging 2010;32:903–913. © 2010 Wiley‐Liss, Inc.
Single‐dose time‐resolved contrast enhanced hybrid MR angiography in diagnosis of peripheral arterial disease: Compared with digital subtraction angiography
Authors: Wang Chun‐Chieh , Liang Huei‐Lung , Hsiao Chia‐Chi , Chen Matt Chiung‐Yu , Wu To‐Ho , Wu Chieh‐Jen , Huang Jer‐Shyung , Lin Yih‐Huei , Pan Huay‐Ben 
Published: September 2010

AbstractPurposeTo prospectively study the diagnostic performance of hybrid single‐dose contrast‐enhanced MRA of peripheral arterial disease (PAD), with digital subtraction angiography (DSA) as the reference standard.Materials and MethodsHybrid MRA, combining time resolved imaging of contrast kinetics and two‐station bolus‐chase sequences, of lower limb was performed in 31 PAD patients (21 men, 10 women; mean age, 72 years) with two separate gadobenate dimeglumine (8 mL) injections in each sequence. Two independent blinded readers analyzed the vascular stenosis (32 segments in each limb). Sensitivity, specificity, and accuracy in all vascular segments and segments below popliteal artery were calculated. Interobserver agreements on MRA and intermodality agreements between MRA and DSA were calculated by using k statistics.ResultsSensitivity, specificity, and accuracy of the hybrid MRA with regard to hemodynamically significant stenosis in all vascular segments were 92%, 97%, and 95% for reader 1, and 90%, 92%, and 92%, for reader 2, respectively. The interobsever agreements on MRA were good (k = 0.77–0.74) for all‐grade stenosis, and excellent (k = 0.82–0.81) for hemadynamically significant stenosis. The intermodality agreements are good to excellent (k = 0.73–0.94).ConclusionSingle‐dose hybrid MRA is a safe and reliable noninvasive alternative to conventional DSA in the assessment of PAD patients. J. Magn. Reson. Imaging 2010;32:935–942. © 2010 Wiley‐Liss, Inc.
Increase in blood–brain barrier permeability, oxidative stress, and activated microglia in a rat model of blast‐induced traumatic brain injury
Authors: Readnower Ryan D. , Chavko Mikulas , Adeeb Saleena , Conroy Michael D. , Pauly James R. , McCarron Richard M. , Sullivan Patrick G. 
Published: September 2010

AbstractTraumatic brain injury (TBI) as a consequence of exposure to blast is increasingly prevalent in military populations, with the underlying pathophysiological mechanisms mostly unknown. In the present study, we utilized an air‐driven shock tube to investigate the effects of blast exposure (120 kPa) on rat brains. Immediately following exposure to blast, neurological function was reduced. BBB permeability was measured using IgG antibody and evaluating its immunoreactivity in the brain. At 3 and 24 hr postexposure, there was a transient significant increase in IgG staining in the cortex. At 3 days postexposure, IgG immunoreactivity returned to control levels. Quantitative immunostaining was employed to determine the temporal course of brain oxidative stress following exposure to blast. Levels of 4‐hydroxynonenal (4‐HNE) and 3‐nitrotyrosine (3‐NT) were significantly increased at 3 hr postexposure and returned to control levels at 24 hr postexposure. The response of microglia to blast exposure was determined by autoradiographic localization of 3H‐PK11195 binding. At 5 days postexposure, increased binding was observed in the contralateral and ipsilateral dentate gyrus. These regions also displayed increased binding at 10 days postexposure; in addition to these regions there was increased binding in the contralateral ventral hippocampus and substantia nigra at this time point. By using antibodies against CD11b/c, microglia morphology characteristic of activated microglia was observed in the hippocampus and substantia nigra of animals exposed to blast. These results indicate that BBB breakdown, oxidative stress, and microglia activation likely play a role in the neuropathology associated with TBI as a result of blast exposure. © 2010 Wiley‐Liss, Inc.
Effects of intermittent hydrostatic pressure and BMP‐2 on osteoarthritic human chondrocyte metabolism in vitro
Authors: Smith R.L. , Lindsey D.P. , Dhulipala L. , Harris A.H.S. , Goodman S.B. , Maloney W.J. 
Published: September 2010

AbstractPurposeThis study examined effects of intermittent hydrostatic pressure (IHP) and a chondrogenic growth factor, bone morphogenetic protein‐2 (BMP‐2), on anabolic, catabolic, and other metabolic markers in human osteoarthritic (OA) chondrocytes in vitro.MethodsArticular chondrocytes, isolated from femoral OA cartilage and maintained in high‐density monolayer culture, were examined for effects of BMP‐2 and IHP on gene expression of matrix‐associated proteins (aggrecan, type II collagen, and SOX9) and catabolic matrix metalloproteinases (MMP‐2 and MMP‐3) and culture medium levels of the metabolic markers MMP‐2, nitric oxide (NO), and glycosaminoglycan (GAG). The results were analyzed using a mixed linear regression model to investigate the effects of load and growth factor concentration.ResultsIHP and BMP‐2 modulated OA chondrocyte metabolism in accordance with growth factor concentration independently, without evidence of synergism or antagonism. Each type of stimulus acted independently on anabolic matrix gene expression. Type II collagen and SOX9 gene expression were stimulated by both IHP and BMP‐2 whereas aggrecan was increased only by BMP‐2. IHP exhibited a trend to decrease MMP‐2 gene expression as a catabolic marker whereas BMP‐2 did not. NO production was increased by addition of BMP‐2 and IHP exhibited a trend for increased levels. GAG production was increased by BMP‐2.ConclusionsThis study confirmed the hypothesis that human OA chondrocytes respond to a specific type of mechanical load, IHP, through enhanced articular cartilage macromolecule gene expression and that IHP, in combination with a chondrogenic growth factor BMP‐2, additively enhanced matrix gene expression without interactive effects. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:361–368, 2011
Ultrasound propagation velocity and broadband attenuation can help evaluate the healing process of an experimental fracture
Authors: Barbieri Giuliano , Barbieri Cláudio Henrique , Mazzer Nilton , Pelá Carlos Alberto 
Published: September 2010

AbstractUltrasonometry seems to have a future for the evaluation of fracture healing. Ultrasound propagation velocity (USPV) significantly decreases at the same time that bone diameter decreases as healing takes place, thus approaching normal values. In this investigation, both USPV and broadband ultrasound attenuation (BUA) were measured using a model of a transverse mid‐diaphyseal osteotomy of sheep tibiae. Twenty‐one sheep were operated and divided into three groups of seven, according to the follow‐up period of 30, 60, and 90 days, respectively. The progress of healing of the osteotomy was checked with monthly conventional radiographs. The animals were killed at the end of the period of observation of each group, both operated‐upon and intact tibiae being resected and submitted to the measurement of underwater transverse and direct contact transverse and longitudinal USPV and BUA at the osteotomy site. The intact left tibia of the 21 animals was used for control, being examined on a symmetrical diaphyseal segment. USPV increased while BUA decreased with the progression of healing, with significant differences between the operated and untouched tibiae and between the periods of observation, for most of the comparisons. There was a strong negative correlation between USPV and BUA. Both USPV and BUA directly reflect and can help predict the healing of fractures, but USPV alone can be used as a fundamental parameter. Ultrasonometry may be of use in clinical application to humans provided adequate adaptations can be developed. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:444–451, 2011
Resonance Raman spectroscopy and theoretical study on the photodissociation dynamics of formanilide in S3 state
Authors: Pei Kemei , Li Fanglong , Dong Xiaohui , Zheng Xuming 
Published: September 2010

AbstractResonance Raman spectra were obtained for formanilide (FA) in acetonitrile solution with 239.5‐ and 245.9‐nm excitation wavelengths in resonance with the S3 state, and density functional theory (DFT) was used to elucidate the electronic transitions and resonance Raman spectra of FA. The spectra indicate that, in the Franck–Condon region, photodissociation dynamics has a multidimensional character with the motions mainly along the CO stretching υ8, the ring CC stretch υ9, the NH wag and ring CCH in‐plane bend υ11, the NH wag and ring CCH in‐plane bend υ12, ring CC stretch and ring CCH in‐plane bend υ16, the NH wag and ring CCH in‐plane bend υ17, the ring CCH in‐plane bend υ18, and the ring trigonal bend υ24. The excited‐state dynamics of the S3 state is discussed, and the results are compared with those previously reported for benzamide (BA) to examine the N‐ or C‐terminal‐substituted aromatic effect of the peptide bond. Copyright © 2010 John Wiley & Sons, Ltd.