bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uterine sarcomas versus leiomyomas: Gray‐scale and Doppler sonographic findings
Authors: Aviram Rami , Ochshorn Yifat , Markovitch Ofer , Fishman Ami , Cohen Ilan , Altaras Marco M. , Tepper Ron 
Published: December 2004

AbstractPurposeThe aim of the study was to evaluate the contribution of gray‐scale sonography and Doppler flow studies in differentiating between uterine sarcomas of different histologic types and leiomyomas.Patients and MethodsThe study included 111 patients, divided retrospectively into 2 groups: 98 patients with leiomyomas and 13 with postoperative diagnosis of uterine sarcoma. This latter group was further divided into a group of 6 patients with uterine leiomyosarcoma and 7 with malignant mixed mesodermal tumor. The gray‐scale sonograms and Doppler parameters in the 3 groups were compared.ResultsThe patients with leiomyomas were younger than those with sarcomas (52 years ± 11 versus 65 years ± 15, p < 0.05). No differences were noted between the 3 groups regarding gravidity, parity, symptoms upon admission, or findings during physical examination. The sonographic appearances of the leiomyomas were similar to those of the leiomyosarcomas, but in 6/7 cases, they were different from those of the malignant mixed mesodermal tumors. There was a significant difference between the mean resistance index in arterioles of the leiomyomas (0.59 ± 0.01) and that of the malignant mixed mesodermal tumors (0.41 ± 0.06) (P < 0.001) but not between those of the leiomyomas and the leiomyosarcomas (0.49 ± 0.18).ConclusionsDoppler flow studies may assist in differentiating between leiomyomas and malignant mixed mesodermal tumors but not between leiomyomas and leiomyosarcomas. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 33:10–13, 2005
Color Doppler sonographic findings in penile fracture
Authors: Kervancioglu Selim , Ozkur Ayhan , Bayram M. Metin 
Published: December 2004

AbstractWe performed color Doppler sonographic examination on 4 patients, 3 of whom had preliminary diagnoses of penile fracture and 1 of whom had undergone an operation due to penile fracture a year previously. Color Doppler sonography helped evaluate the relationships between the hematoma and the vascular structures and aided in differential diagnosis of the vascular injuries that may accompany tunical rupture (or have similar clinical presentations) and Mondor's disease; thus, this method has a crucial role in choosing the treatment approach. Color Doppler sonography may also assist in the follow‐up of patients after surgical or conservative treatment. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 33:38–42, 2005
Transrectal sonographic features of prostatic intraepithelial neoplasia: Correlation with pathologic findings
Authors: Özden Eriz , Göğüş Çağatay , Karamürsel Tamer , Baltacı Sümer , Küpeli Sadettin , Göğüş Orhan 
Published: December 2004

AbstractPurposeThis study was conducted to evaluate the transrectal sonographic (TRUS) features of prostatic intraepithelial neoplasia (PIN) by comparing the histopathologic results with TRUS findings in patients who had undergone TRUS‐guided prostate biopsy.MethodsFrom an initial set of 307 patients who underwent TRUS‐guided prostate biopsy, TRUS findings for 44 patients whose pathologic results were consistent with PIN were reviewed retrospectively. Among these 44 patients, 12 had only PIN, 20 PIN associated with prostatitis, and 12 PIN associated with prostate cancer foci. After exclusion of the foci that included PIN associated with prostatitis and PIN associated with prostate cancer at the same site, the pathologic results for the core specimens from the 100 PIN foci were correlated with TRUS findings according to their location. The sonographic features sought were hypoechoic areas and regions of heterogeneous echogenicity.ResultsPositive TRUS findings were detected in 43% of PIN and 36% of high‐grade PIN (HGPIN) focise. For the HGPIN foci with positive TRUS findings, the detected sonographic features were clusters of millimetric hypoechoic foci (CMHF) (53%), hypoechoic areas with well‐defined borders (27%), and heterogeneous echogenicity (20%) (not significant). The sensitivity of the presence of CMHF for the diagnosis of HGPIN was only 19%.ConclusionsTRUS‐detected CMHF may indicate HGPIN. Because of the limited sensitivity of this finding, TRUS detection of CMHF does not warrant biopsy, although these lesions warrant close monitoring. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 33:5–9, 2005
Prevalence of carotid artery stenosis in Taiwanese patients with one ischemic stroke
Authors: Tan Teng‐Yeow , Chang Ku‐Chou , Liou Chia‐Wei , Schminke Ulf 
Published: December 2004

AbstractPurposeEthnic differences in the distribution of atherosclerosis in the brain‐supplying vessels are well described. However, only scarce data exist on the prevalence of extracranial carotid artery stenosis in Taiwanese patients who have had a single ischemic stroke.MethodsColor‐coded duplex sonography was used to evaluate the carotid arteries in a hospital‐based study on 276 consecutive first‐time Taiwanese stroke patients. Significant atherosclerotic lesions of the internal carotid arteries (ICA) were defined as a stenosis of more than 50% or an occlusion.ResultsThe prevalence of significant carotid lesions was 6% (35/552) in the entire cohort and 8% (17/224) in patients with hemispheric strokes. Among patients with large‐artery atheroscleroses, according to criteria of the Trial of Org 10172 in Acute Stroke Treatment, only 27% had significant extracranial ICA disease whereas 69% had intracranial vessel stenoses. Older patients tended to have more severe ICA lesions, while other risk factors were not correlated with carotid stenosis.ConclusionThe prevalence of more than 50% ICA stenosis was low in Taiwanese patients with first hemispheric ischemic strokes, indicating that it is not a major cause of ischemic stroke in this population. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 33:1–4, 2005
Sonography in diagnosis and follow‐up of serosal eosinophilic gastroenteritis treated with corticosteroid
Authors: Buljevac Mladen , Crnčević Urek Marija , Štoos‐Veić Tajana 
Published: December 2004

AbstractAn 18‐year‐old patient presented with abdominal pain, nausea, and low‐grade fever. Sonography showed ascites in the region of the terminal ileum, and the presence of peritoneal nodules suggested peritoneal inflammation. Cytologic analysis of ascites revealed numerous eosinophils. Sonographic visualization of nodular peritoneal deposits associated with eosinophilic ascites permitted the diagnosis of the serosal form of eosinophilic gastroenteritis. The absence of mucosal and muscular involvement in the bowel wall was confirmed by endoscopy and CT. Two weeks of 20 mg/day oral prednisolone led to relief of the patient's symptoms, with normalization of laboratory parameters and sonographic findings. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 33:43–46, 2005
Calibration of gradient propagation delays for accurate two‐dimensional radiofrequency pulses
Authors: Davies Nigel P. , Jezzard Peter 
Published: December 2004

AbstractHardware‐related delays between the requested and actual start times of the gradient waveforms on each physical axis are of particular importance for multidimensional selective excitation in which the synchronization of gradient and radiofrequency (RF) waveforms is critical. A method is proposed for the accurate calibration of gradient propagation delays to optimize the spatial accuracy of 2D RF pulses, although the results may also be used to reduce artifacts in other MR techniques. The sensitivity of 2D RF pulses to uncorrected time shifts between the gradient and RF waveforms was exploited to calibrate accurately the propagation delays on each physical gradient axis. This was achieved using a technique that relates the effect of gradient delays in the component waveforms of a constant‐angular rate spiral k‐space trajectory 2D RF pulse to the spatial location of the subsequent excitation profile. Comparison was also made with a procedure based on a previously described k‐space plotting method, showing broad agreement, but with some discrepancies that illustrate the value of a self‐referenced correction method for multidimensional RF pulses. Magn Reson Med 53:231–236, 2005. © 2004 Wiley‐Liss, Inc.
Analysis and correction of gradient nonlinearity and B0 inhomogeneity related scaling errors in two‐dimensional phase contrast flow measurements
Authors: Peeters Johannes M. , Bos Clemens , Bakker Chris J. G. 
Published: December 2004

AbstractPhase contrast flow measurements will be increasingly biased at eccentric positions, where nonlinearity of gradients and inhomogeneity of the main field become important. In theory, they scale the result of phase contrast flow values in two ways: incorrect velocity encoding of moving spins and geometric distortion of the vessel cross‐sectional area. A flow phantom, consisting of a 3D grid of interconnected tubes, was used to determine the spatial dependence of the associated scaling factors, which demonstrate that scaling errors in flow can be as large as 20% within the examined volume of 336 × 336 × 336 mm3. The same phantom was also used to determine and minimize concomitant gradient effects. Correction of the off‐center flow values with the local scaling factors and the concomitant gradient phase improves the measurement accuracy substantially, both in the flow phantom and in a volunteer study. Magn Reson Med 53:126–133, 2005. © 2004 Wiley‐Liss, Inc.
Accelerating MR diffusion tensor imaging via filtered reduced‐encoding projection‐reconstruction
Authors: Jiang Yi , Hsu Edward W. 
Published: December 2004

AbstractMR diffusion tensor imaging (DTI) is a promising tool for characterizing the microstructure of ordered tissues. However, its practical applications are hampered by relatively low signal‐to‐noise‐ratio and spatial and temporal resolution. Reduced‐encoding imaging (REI) via k‐space sharing with constrained reconstruction has previously been shown to be effective for accelerating DTI, although the implementation was based on rectilinear k‐space sampling. Due to the intrinsic oversampling of central k‐space and allowance for isotropic downsampling, projection‐reconstruction (PR) imaging may be better suited for REI. In this study, regularization procedures, including radial filtering and baseline signal correction to adequately reconstruct reduced encoded PR imaging data, are investigated. The proposed filtered reduced‐encoding projection‐reconstruction (FREPR) technique is applied to DTI tissue fiber orientation and fractional anisotropy (FA) measurements. Results show that FREPR offers improved reconstructions of the reduced encoded images and on an equal total scan‐time basis provides more accurate fiber orientation and FA measurements compared to rectilinear k‐space sampling‐based REI methods or a control experiment consisting of only fully encoded images. These findings suggest a potentially significant role of FREPR in accelerating repeated imaging and improving the data acquisition‐time efficiency of DTI experiments. Magn Reson Med 53:93–102, 2005. © 2004 Wiley‐Liss, Inc.
Use of phased array coils for a determination of absolute metabolite concentrations
Authors: Natt Oliver , Bezkorovaynyy Vitaliy , Michaelis Thomas , Frahm Jens 
Published: December 2004

AbstractThis work describes the use of phased array coils for a quantification of absolute metabolite concentrations. The method is demonstrated for single‐voxel localized proton MRS of human brain with an eight‐element receive‐only head coil. It is based on the transmitter reference amplitude of the body coil used for RF transmission. A relative sensitivity of every element of the phased array coil is derived from a combination of two reference scans without water suppression that correspond to either the body coil in transmit‐receive mode or the phased array coil in conjunction with body coil excitation. Experimental results were obtained at 2.9 T for both phantoms and 12 human subjects in different locations of gray and white matter. The data demonstrate that the procedure is technically robust and without a penalty in measuring time. Moreover, it takes full advantage of the signal‐to‐noise gain for quantitative proton MRS and may be extended to other phased array coils without the need for a recalibration. Magn Reson Med 53:3–8, 2005. © 2004 Wiley‐Liss, Inc.
Successful intramuscular neurotization is dependent on the denervation period. A histomorphological study of the gracilis muscle in rats
Authors: Keilhoff Gerburg , Fansa Hisham 
Published: December 2004

AbstractTo characterize the extent to which reinnervation potential depends on the duration of denervation, intramuscular neurotization of the gracilis muscle was performed either immediately or 2, 4, 6, and 8 weeks after transection of the obturator nerve. For neurotization, the sciatic nerve was split into three fascicle groups and fixed intramuscularly. Muscle morphology after 6 weeks of regeneration was identified with anti‐myosin immunohistochemistry and NADH staining. Newly formed motor endplates were characterized using acetylcholinesterase staining and electron microscopy. Wet muscle weight ratio indicated the functional state of synapses. Depending on the denervation period, three levels of regenerative outcome were evident. Best results were seen after immediate neurotization or after 2 weeks of denervation. Regeneration, although at a significantly lower level, also occurred after denervation periods of 4 and 6 weeks. Regeneration following neurotization after 8 weeks of denervation was negligible. Quantity and quality of motor endplate formation depended on the denervation period. Thus, in special clinical situations intramuscular neurotization within a distinct time window provides a good reconstructive option. Muscle Nerve, 2005
Motor evoked potentials (MEP) and evoked pressure curves (EPC) from the urethral compressive musculature (UCM) by functional magnetic stimulation in healthy volunteers and patients with neurogenic incontinence
Authors: Schmid Daniel M. , Curt A. , Hauri D. , Schurch B. 
Published: December 2004

AbstractAimsThe aim of this study is to assess neurogenic lesions of the somatomotor efferent nervous pathway to the urethral compressive musculature (UCM) by means of motor evoked potentials (MEP) and simultaneously recorded evoked pressure curves (EPC).MethodsNine healthy subjects and 33 patients (15 spinal cord injury, 14 cauda equina lesion, and 4 multiple sclerosis (MS)) with neurogenic urinary incontinence were prospectively examined by means of urodynamics and electrophysiology. MEP responses from the UCM were evoked after transcranial (tc) and lumbosacral (ls) single pulse magnetic stimulation. A ratio out of tc/ls latencies was calculated to distinguish between central (i.e., spinal) and peripheral lesions. The mechanical UCM pressure responses ( = EPC) were recorded simultaneously with electromyographic (EMG) recordings using a microtip pressure transducer catheter with integrated bipolar surface electrodes.ResultsIn nine healthy subjects the central latency was 19.0 msec, the peripheral latency was 4.25 msec, and the ratio was 4.4. In patients with incomplete spinal cord lesion the central latency was significantly delayed (22.7 msec), whereas the peripheral latency was normal. The ratio (5.5) was increased. Thirteen of these 15 patients suffered from neurogenic incontinence. Patients with a complete spinal lesion showed no UCM reaction after tc stimulation, whereas peripheral responses were normal. Patients with MS showed significantly prolonged central latencies (25.5 msec). The increased ratio of 6.0 indicated a spinal lesion. Ten patients with incomplete cauda equina lesions and urinary incontinence had normal central latencies but prolonged peripheral latencies of 6.7 msec. The ratio of 3.4 indicated a lesion of the sacral caudal roots. In patients with complete cauda injury neither central nor peripheral responses could be evoked. Tc evoked mechanical pressure responses (i.e., contractions) from the UCM could only be recorded in intact or incompletely injured spinal and peripheral motor nervous pathways, whereas they could be evoked after ls stimulation only in cases with partially preserved sacral caudal roots independent of a spinal lesion.ConclusionsMEP and EPC from the UCM proved to be a well tolerated diagnostic tool in patients with neurogenic incontinence that distinguished central and peripheral lesions of the motor efferent pathways to the UCM. © 2004 Wiley‐Liss, Inc.
A high‐fidelity numerical method for the simulation of compressible flows in cylindrical geometries
Authors: Keiderling F. , Müller S. B. , Kleiser L. 
Published: December 2004

AbstractA wide range of flows of practical interest occur in cylindrical geometries. In order to simulate such flows, an available compact finite‐difference simulation code [1] was adapted by introducing a mapping that expresses cylindrical coordinates as generalized coordinates. This formulation is conservative and avoids problems associated with the classical formulation of the Navier‐Stokes equations in cylindrical coordinates. The coordinate singularity treatment follows [2] and is modified for generalized coordinates. To retain high‐order numerical accuracy, a Fourier spectral method is employed in the azimuthal direction combined with mode clipping to alleviate time‐step restrictions due to a very fine grid spacing near the singularity at the axis (r = 0). An implementation of this scheme was successfully validated by a simulation of a tripolar vortex formation and by comparison with linear stability theory. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Partial Differential Algebraic Dynamic Model of a Molten Carbonate Fuel Cell
Authors: Sternberg Kati , Chudej Kurt , Pesch Hans Josef 
Published: December 2004

AbstractFuel cells convert chemical energy of hydrogen directly into electrical energy providing a clean and highly efficient source of electricity. In this paper we present a partial differential algebraic equation model that describes the gas flow, temperature and electrical potential depending on the reaction kinetics in a molten carbonate fuel cell.Furthermore we will present results for the numerical simulation of this time dependent two dimensional model. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Categorical View to Structural Complexity
Authors: Aparecida dos Santos Leal Liara , Moraes Claudio Dalcidio , Vieira Toscani Laira 
Published: December 2004

AbstractIn the present work we are interested in to provide a universal language for supporting formalisms to specify the approximation hierarchy system for an abstract NP‐hard optimization problem. This work grew from the idea of providing a categorical view of structural complexity to optimization problems. The direction is aimed towards actually exploring the connections among the structural complexity aspects and categorical concepts, which may be viewed in a high‐level, in a structuralistic sense. After introducing the optimization problems categories OPTS and OPT, as well as related questions, a formal system modelling the approximation hierarchy of a given optimization problem is provided, based on categorical shape theory. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of Aeroelastic Instabilities for Systems with Random Parameters
Authors: Löhr Michael , Dinkler Dieter 
Published: December 2004

AbstractThis paper presents a method for the numerical investigation of aeroelastic systems considering random properties of aerodynamic forces. The numerical analysis of aeroelastic instabilities is based on an eigenvalue problem with random coefficients, thus enabling the analysis of the random characteristics of critical wind velocities, respectively. The aerodynamic coefficients are treated as normally distributed random variables. An expansion in terms of a polynomial chaos scheme is applied in order to describe the statistical properties of the critical wind velocities. Hence, the reliability of structures against aeroelastic vibration phenomena can be estimated. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A decomposition approach for optimal control problems with integer innerpoint state constraints
Authors: Glocker Markus 
Published: December 2004

AbstractA large class of optimal control problems for hybrid dynamic systems can be formulated as mixed‐integer optimal control problems (MIOCPs). A decomposition approach is suggested to solve a special subclass of MIOCPs with mixed integer inner point state constraints. It is the intrinsic combinatorial complexity of the discrete variables in addition to the high nonlinearity of the continuous optimal control problem that forms the challenges in the theoretical and numerical solution of MIOCPs.During the solution procedure the problem is decomposed at the inner time points into a multiphase problem with mixed integer boundary constraints and phase transitions at unknown switching points. Due to a discretization of the state space at the switching points the problem can be decoupled into a family of continuous optimal control problems (OCPs) and a problem similar to the asymmetric group traveling salesman problem (AGTSP).The OCPs are transcribed by direct collocation to large‐scale nonlinear programming problems, which are solved efficiently by an advanced SQP method. The results are used as weights for the edges of the graph of the corresponding TSP‐like problem, which is solved by a Branch‐and‐Cut‐and‐Price (BCP) algorithm.The proposed approach is applied to a hybrid optimal control benchmark problem for a motorized traveling salesman. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Two Phase Mixture Model based on Bone Observation
Authors: Kühn R.‐R. , Hauger W. , Staat M. , Sponagel S. 
Published: December 2004

AbstractAn optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff's law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)