bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oncological and functional results of cryosurgical therapy of enchondromas and chondrosarcomas grade 1
Authors: van der Geest I.C.M. , de Valk M.H. , de Rooy J.W.J. , Pruszczynski M. , Veth R.P.H. , Schreuder H.W.B. 
Published: July 2008

AbstractBackground and ObjectivesCryosurgery using liquid nitrogen is used as adjuvant treatment after intralesional resection of bone tumours to induce cell death. It is applied to enlarge the oncological margins of resection and to reduce the local recurrence rate. The objective of this study is to analyze the oncological and functional results.MethodsWe studied the oncological and functional results of curettage and cryosurgery in 123 patients with 130 tumors. There were 75 enchondromas and 55 chondrosarcomas grade 1. The minimal follow‐up period for all patients was 2 years (range 24–119 months).ResultsDuring follow‐up one local recurrence of an active enchondroma and one local recurrence of an aggressive enchondroma occurred. They were treated with curettage and cryosurgery again. Both patients were disease‐free at minimum of 3 years follow‐up. No local recurrences after treatment of chondrosarcoma grade 1 were seen. Functional scores, according to the MSTS scoring system, showed an average score of 28 points (94%) at 2 years follow‐up. Post‐operative fractures were seen in 18 patients (14%).ConclusionsCurettage and cryosurgery for enchondroma and chondrosarcoma grade 1 has excellent oncological and functional results. The post‐operative management has been adjusted to reduce the number of fractures. J. Surg. Oncol. © 2008 Wiley‐Liss, Inc.
High expression of human nonmetastatic clone 23 type 1 in cancer of uterine cervix and its association with poor cell differentiation and worse overall survival
Authors: Hsu Chien‐Gang , Lin Long‐Yau , Ko Jiunn‐Liang , Yang Shun‐Fa , Chang Han , Lin Ching‐Yi , Tsai Hsiu‐Ting , Chen Shiuan‐Chih , Chen Shu‐Chen , Wang Po‐Hui 
Published: July 2008

AbstractBackground and ObjectivesThe role of human nonmetastatic clone 23 type 1 (nm23‐H1), a metastasis‐associated gene, is less clear‐cut in cancer of uterine cervix; therefore, we investigate its expression in cancer tissues and its correlation with clinicopathologic variables and survival of patients.MethodsThirty cervical cancer tissues and their normal counterparts were collected to evaluate quantitative nm23‐H1 mRNA expression. From them, 16 cancer and 16 normal tissues were collected and added with another 64 cancer tissues to construct a 96‐tissue core microarray for immunohistochemical study. We evaluated the relationships among nm23‐H1 immunostaining using semi‐quantitative H scores, clinicopathologic parameters, recurrence and survival in cervical cancer patients.ResultsNm23‐H1 mRNA expression and H score (median H scores: 2.0 vs. 0.3, P = 0.001) were higher in cervical cancer tissues than normal counterparts, respectively. Nm23‐H1 expression was significantly associated with depth of stromal invasion (P = 0.003), tumor diameter (P = 0.044) and cell differentiation (P = 0.025). Other than stage II, poor cell differentiation as well as positive parametrium invasion and lymph node metastasis, positive nm23‐H1 expression was significantly correlated with poor overall survival.ConclusionHigh nm23‐H1 expression is predictive of worse overall survival for cervical cancer patients. J. Surg. Oncol. © 2008 Wiley‐Liss, Inc.
Multiparametric analysis of amino acids and organic acids in rat brain tissues using GC/MS
Authors: Lin Jingchao , Su Mingming , Wang Xiaoyan , Qiu Yunping , Li Houkai , Hao Jin , Yang Hongzhou , Zhou Mingmei , Yan Chao , Jia Wei 
Published: July 2008

AbstractUsing design of experiment (DOE) theory coupled with multivariate statistical analysis, we have developed a simple and reliable GC/MS‐based analytical assay for simultaneous analysis of amino acids and organic acids in rat brain tissue samples. The process of water extraction (pH 10.0) was extensively evaluated using brain tissue samples and a set of 21 reference standards. Acceptable calibration curves were obtained over a wide concentration range, 0.2–35.0 μg/mL for standards and 15.0–2.4 mL/g (tissue) for brain tissue samples. The precision was mostly better than 10% for both the mixed standards and the brain tissue samples. The brain tissue samples exhibited good stability within 48 h with RSD generally less than 15%. Furthermore, the developed analytical method was successfully applied in distinguishing the subtle variation among different parts of the brain tissues, such as cerebral cortex, hippocampus, and thalamus.
Determination of primary biogenic amines in various food products using isocratic HPLC with 3‐(4‐chlorobenzoyl)‐quinoline‐2‐carboxaldehyde as a new precolumn fluorogenic reagent
Authors: Zhang Niu , Wang Hong , Guo Xiao‐Feng , Zhang Hua‐Shan 
Published: July 2008

AbstractA simple HPLC approach has been successfully established for the sensitive determination of six biogenic amines (BAs) in food samples. The method involves derivatization with 3‐(4‐chlorobenzoyl)‐quinoline‐2‐carboxaldehyde newly synthesized as a new fluorogenic reagent followed by LC isocratic elution mode. The optimization of both derivatization and separation conditions is carefully studied. Related analyses of the eluted compounds, in the presence of MeOH/THF/H2O (78:2.5:19.5 v/v/v) as a mobile phase containing 8 mM, pH 6.0 phosphate buffer solution, have been carried out on a C18 column. The LOD (S/N = 3) of 2.5 nM, RSD value from 1.0 to 5.1% in peak areas, and good response linearity (R2 >0.9936) are provided with fluorescence detection at λex/λem = 480/545 nm. Obviously, recovery ranging from 95 to 107% in this method demonstrates its accuracy for determination of histamine, tyramine, 2‐phenylethylamine, putrescine, cadaverine, and spermidine in the storage fish sample. Thus, the present method could be developed to monitor BAs in fish, cucumber, and spinach samples.
Spatial distribution of RF‐induced E‐fields and implant heating in MRI
Authors: Nordbeck Peter , Fidler Florian , Weiss Ingo , Warmuth Marcus , Friedrich Michael T. , Ehses Philipp , Geistert Wolfgang , Ritter Oliver , Jakob Peter M. , Ladd Mark E. , Quick Harald H. , Bauer Wolfgang R. 
Published: July 2008

AbstractThe purpose of this study was to assess the distribution of RF‐induced E‐fields inside a gel‐filled phantom of the human head and torso and compare the results with the RF‐induced temperature rise at the tip of a straight conductive implant, specifically examining the dependence of the temperature rise on the position of the implant inside the gel. MRI experiments were performed in two different 1.5T MR systems of the same manufacturer. E‐field distribution inside the liquid was assessed using a custom measurement system. The temperature rise at the implant tip was measured in various implant positions and orientations using fluoroptic thermometry. The results show that local E‐field strength in the direction of the implant is a critical factor in RF‐related tissue heating. The actual E‐field distribution, which is dependent on phantom/body properties and the MR‐system employed, must be considered when assessing the effects of RF power deposition in implant safety investigations. Magn Reson Med 60:312–319, 2008. © 2008 Wiley‐Liss, Inc.
Fast, exact k‐space sample density compensation for trajectories composed of rotationally symmetric segments, and the SNR‐optimized image reconstruction from non‐Cartesian samples
Authors: Mitsouras Dimitris , Mulkern Robert V. , Rybicki Frank J. 
Published: July 2008

AbstractA recently developed method for exact density compensation of non uniformly arranged samples relies on the analytically known cross‐correlations of Fourier basis functions corresponding to the traced k‐space trajectory. This method produces a linear system whose solution represents compensated samples that normalize the contribution of each independent element of information that can be expressed by the underlying trajectory. Unfortunately, linear system‐based density compensation approaches quickly become computationally demanding with increasing number of samples (i.e., image resolution). Here, it is shown that when a trajectory is composed of rotationally symmetric interleaves, such as spiral and PROPELLER trajectories, this cross‐correlations method leads to a highly simplified system of equations. Specifically, it is shown that the system matrix is circulant block‐Toeplitz so that the linear system is easily block‐diagonalized. The method is described and demonstrated for 32‐way interleaved spiral trajectories designed for 256 image matrices; samples are compensated non iteratively in a few seconds by solving the small independent block‐diagonalized linear systems in parallel. Because the method is exact and considers all the interactions between all acquired samples, up to a 10% reduction in reconstruction error concurrently with an up to 30% increase in signal to noise ratio are achieved compared to standard density compensation methods. Magn Reson Med 60:339–349, 2008. © 2008 Wiley‐Liss, Inc.
Ischemia‐induced changes of intracellular water diffusion in rat glioma cell cultures
Authors: Trouard Theodore P. , Harkins Kevin D. , Divijak Joseph L. , Gillies Robert J. , Galons Jean‐Philippe 
Published: July 2008

AbstractDiffusion‐weighted MRI is commonly used in the diagnosis and evaluation of ischemic stroke because of the rapid decrease observed in the apparent diffusion coefficient (ADC) of tissue water following ischemia. Although this observation has been clinically useful for many years, the biophysical mechanisms underlying the reduction of tissue ADC are still unknown. To help elucidate these mechanisms, we have employed a novel three‐dimensional (3D) hollow‐fiber bioreactor (HFBR) perfused cell culture system that enables cells to be grown to high density and studied via MRI and MRS. By infusing contrast media into the HFBR, signals from intracellular water and extracellular water are spectroscopically resolved and can be investigated individually. Diffusion measurements carried out on C6 glioma HFBR cell cultures indicate that ischemia‐induced cellular swelling results in an increase in the ADC of intracellular water from 0.35 μm2/ms to approximately 0.5 μm2/ms (diffusion time = 25 ms). Magn Reson Med 60:258–264, 2008. © 2008 Wiley‐Liss, Inc.
Quantitative evaluation of oxygenation in venous vessels using T2‐Relaxation‐Under‐Spin‐Tagging MRI
Authors: Lu Hanzhang , Ge Yulin 
Published: July 2008

AbstractNoninvasive measurement of cerebral venous oxygenation can serve as a tool for better understanding fMRI signals and for clinical evaluation of brain oxygen homeostasis. In this study a novel technique, T2‐Relaxation‐Under‐Spin‐Tagging (TRUST) MRI, is developed to estimate oxygenation in venous vessels. This method uses the spin labeling principle to automatically isolate pure blood signals from which T2 relaxation times are determined using flow‐insensitive T2‐preparation pulses. The blood T2 is then converted to blood oxygenation using a calibration plot. In vivo experiments gave a baseline venous oxygenation of 64.8 ± 6.3% in sagittal sinus in healthy volunteers (n = 24). Reproducibility studies demonstrated that the standard deviation across trials was 2.0 ± 1.1%. The effects of repetition time and inversion time selections were investigated. The TRUST technique was further tested using various physiologic challenges. Hypercapnia induced an increase in venous oxygenation by 13.8 ± 1.1%. On the other hand, caffeine ingestion resulted in a decrease in oxygenation by 7.0 ± 1.8%. Contrast agent infusion (Gd‐DTPA, 0.1 mmol/kg) reduced venous blood T2 by 11.2 ms. The results of this study show that TRUST MRI is a useful technique for quantitative assessment of blood oxygenation in the brain. Magn Reson Med 60:357–363, 2008. © 2008 Wiley‐Liss, Inc.
Convertible manganese contrast for molecular and cellular MRI
Authors: Shapiro Erik M. , Koretsky Alan P. 
Published: July 2008

AbstractWe describe here the use of inorganic manganese based particles as convertible MRI agents. As has been demonstrated with iron oxide particles, manganese oxide and manganese carbonate particles can be internalized within phagocytotic cells, being subsequently shuttled to endosomes and/or lysosomes. As intact particles, only susceptibility‐induced MRI contrast is exhibited, most often seen as dark contrast in susceptibility‐weighted images. Modulation of MRI contrast is accomplished by the selective degradation of these particles within the endosomal and lysosomal compartments of cells. Upon particle deconstruction in the endosomes and lysosomes, the dissolved Mn2+ acts as a T1 agent, eliciting bright contrast in T1‐weighted images. This modulation of MRI contrast is demonstrated both in vitro in cells in culture, and also in vivo, in rat brain. These particles are the potential building blocks for an entire class of new environmentally responsive MRI contrast agents. Magn Reson Med 60:265–269, 2008. © 2008 Wiley‐Liss, Inc.
Using GRAPPA to improve autocalibrated coil sensitivity estimation for the SENSE family of parallel imaging reconstruction algorithms
Authors: Hoge W. Scott , Brooks Dana H. 
Published: July 2008

AbstractTwo strategies are widely used in parallel MRI to reconstruct subsampled multicoil image data. SENSE and related methods employ explicit receiver coil spatial response estimates to reconstruct an image. In contrast, coil‐by‐coil methods such as GRAPPA leverage correlations among the acquired multicoil data to reconstruct missing k‐space lines. In self‐referenced scenarios, both methods employ Nyquist‐rate low‐frequency k‐space data to identify the reconstruction parameters. Because GRAPPA does not require explicit coil sensitivities estimates, it needs considerably fewer autocalibration signals than SENSE. However, SENSE methods allow greater opportunity to control reconstruction quality though regularization and thus may outperform GRAPPA in some imaging scenarios. Here, we employ GRAPPA to improve self‐referenced coil sensitivity estimation in SENSE and related methods using very few auto‐calibration signals. This enables one to leverage each methods' inherent strength and produce high quality self‐referenced SENSE reconstructions. Magn Reson Med 60:462–467, 2008. © 2008 Wiley‐Liss, Inc.
Rapid magnetic resonance quantification on the brain: Optimization for clinical usage
Authors: Warntjes J.B.M. , Leinhard O. Dahlqvist , West J. , Lundberg P. 
Published: July 2008

AbstractA method is presented for rapid simultaneous quantification of the longitudinal T1 relaxation, the transverse T2 relaxation, the proton density (PD), and the amplitude of the local radio frequency B1 field. All four parameters are measured in one single scan by means of a multislice, multiecho, and multidelay acquisition. It is based on a previously reported method, which was substantially improved for routine clinical usage. The improvements comprise of the use of a multislice spin‐echo technique, a background phase correction, and a spin system simulation to compensate for the slice‐selective RF pulse profile effects. The aim of the optimization was to achieve the optimal result for the quantification of magnetic resonance parameters within a clinically acceptable time. One benchmark was high‐resolution coverage of the brain within 5 min. In this scan time the measured intersubject standard deviation (SD) in a group of volunteers was 2% to 8%, depending on the tissue (voxel size = 0.8 × 0.8 × 5 mm). As an example, the method was applied to a patient with multiple sclerosis in whom the diseased tissue could clearly be distinguished from healthy reference values. Additionally it was shown that, using the approach of synthetic MRI, both accurate conventional contrast images as well as quantification maps can be generated based on the same scan. Magn Reson Med 60:320–329, 2008. © 2008 Wiley‐Liss, Inc.
Assessment of liver viscoelasticity using multifrequency MR elastography
Authors: Asbach Patrick , Klatt Dieter , Hamhaber Uwe , Braun Jürgen , Somasundaram Rajan , Hamm Bernd , Sack Ingolf 
Published: July 2008

AbstractMR elastography (MRE) allows the noninvasive assessment of the viscoelastic properties of human organs based on the organ response to oscillatory shear stress. Shear waves of a given frequency are mechanically introduced and the propagation is imaged by applying motion‐sensitive gradients. An experiment was set up that introduces multifrequency shear waves combined with broadband motion sensitization to extend the dynamic range of MRE from one given frequency to, in this study, four different frequencies. With this approach, multiple wave images corresponding to the four driving frequencies are simultaneously acquired and can be evaluated with regard to the dispersion of the complex modulus over the respective frequency. A viscoelastic model based on two shear moduli and one viscosity parameter was used to reproduce the experimental wave speed and wave damping dispersion. The technique was applied in eight healthy volunteers and eight patients with biopsy‐proven high‐grade liver fibrosis (grade 3–4). Fibrotic liver had a significantly higher (P < 0.01) viscosity (14.4 ± 6.6 Pa · s) and elastic moduli (2.91 ± 0.84 kPa; 4.83 ± 1.77 kPa) than the viscosity (7.3 ± 2.3 Pa · s) and elastic moduli (1.16 ± 0.28 kPa; 1.97 ± 0.30 kPa) of normal volunteers. Multifrequency MRE is well suited for the noninvasive differentiation of normal and fibrotic liver as it allows the measurement of rheologic material properties. Magn Reson Med 60:373–379, 2008. © 2008 Wiley‐Liss, Inc.
The application of 23Na double‐quantum‐filter (DQF) NMR spectroscopy for the study of spinal disc degeneration
Authors: Ooms Kristopher J. , Cannella Marco , Vega Alexander J. , Marcolongo Michele , Polenova Tatyana 
Published: July 2008

AbstractDegenerative disc disease is an irreversible process that leads to a loss of mechanical integrity and back pain in millions of people. In this report, 23Na double‐quantum‐filtered (DQF) NMR spectroscopy is used to study disc tissues in two stages of degeneration. Initial results indicate that the 23Na DQF signal may be useful for determining the degree of degeneration. The spectral analysis reveals the presence of sodium environments with different residual quadrupolar couplings and T2 relaxation times that we attribute to different regions, or compartments, corresponding to different biochemical regions in the tissue. In general it is found that there are compartments with no residual quadrupolar couplings, compartments with moderate couplings (200 to 1000 Hz), and compartments with couplings ranging from 1500 to 3000 Hz. The results indicate that 23Na DQF NMR spectroscopy provides a probe of the degenerative state of the intervertebral disc tissues, and might hold potential as a novel diagnostic method for detection of disc degeneration. Magn Reson Med 60:246–252, 2008. © 2008 Wiley‐Liss, Inc.
Diffusion‐weighted radial fast spin‐echo for high‐resolution diffusion tensor imaging at 3T
Authors: Sarlls Joelle E. , Pierpaoli Carlo 
Published: July 2008

AbstractThere is a need for an imaging sequence that can provide high‐resolution diffusion tensor images at 3T near air–tissue interfaces. By employing a radial fast spin‐echo (FSE) collection in conjunction with magnitude filtered back‐projection reconstruction, high‐resolution diffusion‐weighted images can be produced without susceptibility artifacts. However, violation of the Carr‐Purcell‐Meiboom‐Gill (CPMG) condition of diffusion prepared magnetization is a prominent problem for FSE trains that is magnified at higher fields. The unique aspect of violating the CPMG condition in trajectories that oversample the center of k‐space and the implications for choosing the solution are examined. For collecting diffusion‐weighted radial‐FSE data at 3T we propose mixed‐CPMG phase cycling of RF refocusing pulses combined with a 300% wider refocusing than excitation slice. It is shown that this approach produces accurate diffusion values in a phantom, and can be used to collect undistorted, high‐resolution diffusion tensor images of the human brain. Magn Reson Med 60:270–276, 2008. © 2008 Wiley‐Liss, Inc.
DWI of the spinal cord with reduced FOV single‐shot EPI
Authors: Saritas Emine Ulku , Cunningham Charles H. , Lee Jin Hyung , Han Eric T. , Nishimura Dwight G. 
Published: July 2008

AbstractSingle‐shot echo‐planar imaging (ss‐EPI) has not been used widely for diffusion‐weighted imaging (DWI) of the spinal cord, because of the magnetic field inhomogeneities around the spine, the small cross‐sectional size of the spinal cord, and the increased motion in that area due to breathing, swallowing, and cerebrospinal fluid (CSF) pulsation. These result in artifacts with the usually long readout duration of the ss‐EPI method. Reduced field‐of‐view (FOV) methods decrease the required readout duration for ss‐EPI, thereby enabling its practical application to imaging of the spine. In this work, a reduced FOV single‐shot diffusion‐weighted echo‐planar imaging (ss‐DWEPI) method is proposed, in which a 2D spatially selective echo‐planar RF excitation pulse and a 180° refocusing pulse reduce the FOV in the phase‐encode (PE) direction, while suppressing the signal from fat simultaneously. With this method, multi slice images with higher in‐plane resolutions (0.94 × 0.94 mm2 for sagittal and 0.62 × 0.62 mm2 for axial images) are achieved at 1.5 T, without the need for a longer readout. Magn Reson Med 60:468–473, 2008. © 2008 Wiley‐Liss, Inc.
Zigzag sampling for improved parallel imaging
Authors: Breuer Felix A. , Moriguchi Hisamoto , Seiberlich Nicole , Blaimer Martin , Jakob Peter M. , Duerk Jeffrey L. , Griswold Mark A. 
Published: July 2008

AbstractConventional Cartesian parallel MRI methods are limited to the sensitivity variations provided by the underlying receiver coil array in the dimension in which the data reduction is carried out, namely, the phase‐encoding directions. However, in this work an acquisition strategy is presented that takes advantage of sensitivity variations in the readout direction, thus improving the parallel imaging reconstruction process. This is achieved by employing rapidly oscillating phase‐encoding gradients during the actual readout. The benefit of this approach is demonstrated in vivo using various zigzag‐shaped gradient trajectory designs. It is shown that zigzag type sampling, in analogy to CAIPIRINHA, modifies the appearance of aliasing in 2D and 3D imaging, thereby utilizing additional sensitivity variations in the readout direction directly resulting in improved parallel imaging reconstruction performance. Magn Reson Med 60:474–478, 2008. © 2008 Wiley‐Liss, Inc.