bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of chondromalacia of the patella with axial inversion recovery–fast spin‐echo imaging
Authors: Lee Sang Hoon , Suh Jin‐Suck , Cho Jaemin , Kim Seong Joon , Kim Sung Jae 
Published: August 2002

AbstractThe purpose of our study was to assess the accuracy of inversion recovery–fast spin‐echo (IR‐FSE) imaging for the evaluation of chondromalacia of the patella. Eighty‐six patients were included, they underwent magnetic resonance (MR) examination and subsequent knee arthroscopy. Medial and lateral facets of the patella were evaluated separately. Axial images were obtained by using IR‐FSE (TR/TE/TI = 3000/25/150 msec; echo train length, 8; 4‐mm thickness; 12‐cm field of view; 512 × 256 matrix; two, number of excitations) with a 1.5‐T MR machine. MR interpretation of chondromalacia was made on the basis of the arthroscopic grading system. Of a total of 172 facets graded, arthroscopy revealed chondromalacia in 14 facets with various grades (G0, 158; G1, 1; G2, 3; G3, 6; G4, 4). Sensitivity, specificity, and accuracy in the chondromalacia grades were 57.1%, 93.0%, and 90.1%, respectively. There was one false‐negative case (G4) and 11 false‐positive cases (G1, eight; G2, two; G3, one). Sensitivity and specificity corrected by one grade difference were improved to 85.7% and 98.1%, respectively. When cartilage changes were grouped into early (corresponding to grade 1 and 2) and advanced (grade 3 and 4) diseases, sensitivity and specificity of the early and advanced diseases were 75% and 94% and 80% and 99%, respectively. IR‐FSE imaging of the knee revealed high specificity but low sensitivity for the evaluation of chondromalacia of the patella. J. Magn. Reson. Imaging 2001;13:412–416. © 2001 Wiley‐Liss, Inc.
Post‐radiotherapy contrast enhancement changes in fast dynamic MRI of cervical carcinoma
Authors: Boss Erik A. , Massuger Leon F.A.G. , Pop Luc A.M. , Verhoef Lia C.G. , Huisman Henk‐Jan , Boonstra Henk , Barentsz Jelle O. 
Published: August 2002

AbstractThis pilot study determines fast dynamic gadolinium enhanced MRI contrast enhancement parameters (onset of enhancement and time to peak enhancement) before and after radiotherapy in 10 cervical carcinoma patients. Before radiotherapy, onset of enhancement and time to peak enhancement were early, with a median of 4.5 and 5.2 seconds, respectively. High‐grade tumors showed early enhancement, compared with low‐grade. After radiotherapy, contrast enhancement patterns differed. In survivors, onset of enhancement after radiotherapy was later than before radiotherapy. In non‐survivors, onset of enhancement after radiotherapy was still early. The median difference in onset of enhancement before and after radiotherapy in survivors and non‐survivors was an increase of 3.2 and a decrease of 1.1 seconds, respectively. Early onset of enhancement after radiotherapy was a better predictor for survival than a high‐signal intensity zone on post radiotherapy unenhanced T1/T2‐weighted MRI. It is concluded that enhancement parameters from fast dynamic Gd‐enhanced MR images can provide additional functional information with regard to tumor vascularization, and may have prognostic significance. It complements clinical examination and unenhanced MRI in determining the effectiveness of radiotherapy treatment in cervical carcinoma. Future studies will focus on the clinical utility and improvements of the estimation of contrast‐enhanced parameters with this new technique. J. Magn. Reson. Imaging 2001;13:600–606. © 2001 Wiley‐Liss, Inc.
Effect of lung inflation on arterial spin labeling signal in MR perfusion imaging of human lung
Authors: Mai Vu M. , Chen Qun , Bankier Alexander A. , Blake Michael , Hagspiel Klaus D. , Knight‐Scott Jack , Berr Stuart S. , Edelman Robert R. 
Published: August 2002

AbstractThe effect of lung inflation on arterial spin‐labeling signal in lung perfusion is investigated. Arterial spin‐labeling schemes, called alternation of selective inversion pulse (ASI) and its hybrid (HASI), which uses blood water as an endogenous, freely diffusible tracer, were applied to magnetic resonance (MR) perfusion imaging of the lung. Perfusion‐weighted images of the lung from nine healthy volunteers were obtained at different time delays. There was a significant signal difference in ASI images acquired at different respiratory phases. Greater signal enhancement has been observed when the volunteers performed breath holding on end expiration than on end inspiration. This is in agreement with the normal physiologic effect of lung inflation on the pressure‐flow relationship of pulmonary vasculature. ASI and HASI perfusion‐weighted images show similar lung features and image quality. Preliminary results from pulmonary embolism patients indicate that arterial spin labeling is sensitive for the detection of areas of perfusion deficit. J. Magn. Reson. Imaging 2001;13:954–959. © 2001 Wiley‐Liss, Inc.
A multielement RF coil for MRI guidance of interventional devices
Authors: Zhang Qiang , Wendt Michael , Aschoff Andrik J. , Lewin Jonathan S. , Duerk Jeffrey L. 
Published: August 2002

AbstractAccurate localization of minimally invasive devices is critical to the success of interventional procedures. Device orientation and tip position are two of the most important pieces of information needed to define device location for magnetic resonance imaging (MRI)‐guided interventional procedures. While a single one‐element micro coil incorporated into an interventional device has proven to be effective in some applications, it can only supply tip position information. However, multiple positions on the device are necessary to also determine its orientation. For this purpose, a novel single micro coil design with three separate winding elements that provides both the device orientation and tip position is described in this study. Definition of MR scan planes, by using the device orientation and the target tissue location, permits automatic tracking of the insertion of the device. Furthermore, devices that include this coil design are permitted to bend to a limited extent. This makes the micro coil design appropriate for many flexible interventional devices. Reliable near‐real‐time tracking of three points on an interventional device is demonstrated on a 0.2T MRI system with modest gradient performance. Phantom and in vivo animal experiments are used to demonstrate the utility of this new coil design. J. Magn. Reson. Imaging 2001;14:56–62. © 2001 Wiley‐Liss, Inc.
Moving‐table reduced‐dose gadolinium‐enhanced three‐dimensional magnetic resonance angiography: Velocity‐dependent method with three‐phase gadolinium infusion
Authors: Kita Miho , Mitani Yasuyuki , Tanihata Hirohiko , Kita Keisuke , Sato Morio , Takizawa Osamu , Laub Gerhard 
Published: August 2002

AbstractThe purpose of this study was to develop a method for reducing gadolinium dose and suppressing venous overlap in moving‐table three‐dimensional (3D) magnetic resonance (MR) angiography from the abdomen to the feet. Thirty‐one patients underwent three‐phase infusion of 16–18 mL of gadolinium: infusion rates and imaging times were determined after taking into account mean blood flow velocity, so that image acquisition was synchronized with peak arterial enhancement at both the first and third stations (velocity‐dependent method). Twenty‐three other patients underwent slow infusion of 38 mL of gadolinium with fixed acquisition time (high‐dose method). The image quality for the two methods was compared. The velocity‐dependent method produced good image quality with significantly less venous overlap than the high‐dose method, especially in the below‐the‐knee region (P < .001). The velocity‐dependent method provides satisfactory MR angiograms using 16–18 mL of gadolinium in patients having various blood flow velocities. J. Magn. Reson. Imaging 2001;14:319–328. © 2001 Wiley‐Liss, Inc.
Dobutamine stress cine‐MRI of cardiac function in the hearts of adult cardiomyocyte‐specific VEGF knockout mice
Authors: Williams Simon‐Peter , Gerber Hans‐Peter , Giordano Frank J. , Peale Franklin V. , Bernstein Lisa J. , Bunting Stuart , Chien Kenneth R. , Ferrara Napoleone , van Bruggen Nicholas 
Published: August 2002

AbstractA mouse model of non‐necrotic vascular deficiency in the adult heart was studied using cine‐magnetic resonance imaging (MRI) and other techniques. The mice lacked cardiomyocyte‐derived vascular endothelial growth factor (VEGF) following a targeted knockout in the ventricular cardiomyocytes. Quantitative endothelial labeling showed that the capillary density was significantly reduced in the hearts of knockout mice. Gene expression patterns suggested that they were hypoxic. Semiautomated MR image analysis was employed to obtain both global and regional measurements of left ventricular function at 10 or more time points through the cardiac cycle. MRI measurements showed a marked reduction in ejection fraction both at rest and under low‐ and high‐dose dobutamine stress. Regional wall thickness, thickening, and displacement were all attenuated in the knockout mice. A prolonged high‐dose dobutamine challenge was monitored by MRI. A maximal response was sustained for 90 minutes, suggesting that it did not depend on endogenous glycogen stores. J. Magn. Reson. Imaging 2001;14:374–382. © 2001 Wiley‐Liss, Inc.
Three‐dimensional MR pulmonary perfusion imaging and angiography with an injection of a new blood pool contrast agent B‐22956/1
Authors: Zheng Jie , Carr James , Harris Katherine , Saker Mark B. , Cavagna Friedrich M. , Maggioni Fabio , Laub Gerhard , Li Debiao , Finn J. Paul 
Published: August 2002

AbstractInitial evaluation of a new blood pool agent, B‐22956/1, for pulmonary imaging was performed in five domestic pigs with artificial embolism. Pre‐embolism 3D pulmonary perfusion images were first acquired by injecting an extravascular agent, gadoteridol. The pulmonary arteries of the pigs were then occluded by the artificial emboli. Post‐embolism perfusion scans were subsequently performed by injecting B‐22956/1. Additional post‐embolism high‐spatial‐resolution angiograms were also acquired. Parenchyma perfusion deficits were well depicted in the post‐embolism perfusion maps. The post‐embolism angiography clearly revealed the location and extent of the filling defects in the pulmonary vessels. Signal intensities of perfusion maps on the normal parenchyma were significantly improved (30%) by using B‐22956/1, in comparison with perfusion images using gadoteridol (P < 0.01). Many pulmonary angiograms with approximately equal contrast could be obtained even at 22 minutes after the injection of B‐22956/1. Our initial results indicate that blood pool agent B‐22956/1 may provide opportunities for whole‐lung‐coverage perfusion mapping and additional high‐resolution target angiograms after a single injection. J. Magn. Reson. Imaging 2001;14:425–432. © 2001 Wiley‐Liss, Inc.
Time‐to‐echo optimization for spin echo magnetic resonance imaging of liver metastasis using superparamagnetic iron oxide particles
Authors: Alger Jeffry R. , Harreld Julie H. , Chen Sloane , Mintorovitch Jan , Lu David S.K. 
Published: August 2002

AbstractSuperparamagnetic iron oxide (SPIO) particles are used as a contrast agent in liver magnetic resonance imaging (MRI). SPIO particles exert their greatest influence on T2‐weighted MR signal intensity. The time‐to‐echo (TE) value that provides optimal contrast has not been systematically studied over the range of clinically relevant field strengths. The purpose of this study was to quantitatively evaluate the TE dependence of the post‐SPIO tumor to liver contrast‐to‐noise ratio (CNR). The hypothesis was that there is a TE that provides an optimal CNR. Subjects having probable metastatic hepatic lesions secondary to colorectal carcinoma were studied. Pre‐ and post‐SPIO images were acquired at TE‐effective (TEeff) equal to 46, 76, and 106 msec by using a turbo spin echo pulse sequence at 0.2 T and 1.5 T. The CNR for all lesions greater than 1 cm in diameter was determined in pre‐ and post‐SPIO images. A paired statistical design was used to identify TE‐related CNR dependencies. The primary findings were as follows. (1) CNR differences attributable to TEeff variation over the range of 46–106 msec were less than 34%. For 0.2 T, TEeff = 46 msec yielded a statistically significantly greater CNR than did TEeff = 76 or 106 msec. The same was true at the higher field strength, but differences were not significant. (2) Signal‐to‐noise measures suggested that SPIO reduced the lesion signal. (3) Post‐SPIO CNR was significantly greater at 1.5 T than at 0.2 T. The observations indicate that over the field strength range of 0.2–1.5 T, CNR differences attributable to the TEeff variation, while being statistically significant in some cases, are small relative to those resulting from the SPIO administration. J. Magn. Reason. Imaging 2001;14:586–594, 2001. © 2001 Wiley‐Liss, Inc.
T1 measurements in cell cultures: A new tool for characterizing contrast agents at 1.5T
Authors: Schmalbrock Petra , Hines Jennifer V. , Lee Shu‐Ming , Ammar Ghada M. , Kwok Edmund Wing‐Chi 
Published: August 2002

AbstractThe objective of this work was to assess the feasibility and accuracy of T1 and relaxivity measurements in cell cultures using 1.5T magnetic resonance imaging (MRI) with the long‐term goal to develop a tool for evaluation of novel paramagnetic agents in a realistic macromolecular environment. This initial study was carried out using MCF‐7 cells treated with independently determined concentrations of Gd‐DTPA. Two cell culture systems were evaluated: cell pellets and single layers of cells grown on microporous inserts. High‐resolution T1 measurements of cell cultures were acquired with two dimensional Inversion Recovery Fast Spin Echo (2D‐IR‐FSE), three dimensional Inversion Recovery Fast Spin Echo (3D‐IR‐FSE), and 3D‐SPGR sequences. The T1 and relaxivity accuracy of these sequences was confirmed with aqueous Gd‐DTPA samples of known concentration. Relaxivities of 1.71 ± 0.15 [mM−1second−1] and 1.55 ± 0.50 [mM−1second−1] were measured in the cell pellets and cell monolayers, respectively, and were different from the value of 4.3 [mM−1second−1] for Gd‐DTPA in water. Both cell pellets and monolayers are suitable for initial assessment of novel MR contrast agents. J. Magn. Reson. Imaging 2001;14:636–648. © 2001 Wiley‐Liss, Inc.
Electrospray tandem mass spectrometric study of ferrocene carbamate ester derivatives of saturated primary, secondary and tertiary alcohols
Authors: Quirke J. Martin E. , Van Berkel Gary J. 
Published: August 2002

AbstractThe fragmentation pathways and mechanisms for 27 ferrocene carbamate esters of saturated alkyl primary, secondary and tertiary alcohols were investigated using energy‐resolved electrospray tandem mass spectrometry (ES‐MS/MS). The mechanisms that control the formation and abundance of the three product ions common to all the derivatives, which appear at m/z 201, 227 and 245, were elucidated. Plotting the relative abundances of the three product ions versus a range of center‐of‐mass collision energies provided a graphical representation of the behavior of the fragmentation process that was directly comparable from compound to compound. As a result, it was possible to compare product ion spectra of the different derivatives to distinguish among different alcohol structural types. Straight‐chain primary alcohols were easily distinguished from tertiary alcohols. Both of these structural types, including positional isomers, produced product ion spectra that were distinct from those of β‐branched primary alcohols, or acyclic secondary alcohols or cyclic secondary alcohols. The latter three alcohol types display similar product ion spectra and therefore cannot be distinguished from one another on the basis of these spectra alone. Published in 2001 by John Wiley & Sons, Ltd.
Determination of polychlorodibenzo‐p‐dioxins and polychlorodibenzofurans by gas chromatography/tandem mass spectrometry and gas chromatography/triple mass spectrometry in a quadrupole ion trap
Authors: Helen C. , Lemasle M. , Laplanche A. , Genin E. 
Published: August 2002

AbstractThe determination of tetra‐ to octachlorodibenzo‐p‐dioxins and tetra‐ to octachlorodibenzofurans (PCCD/Fs) by high‐resolution gas chromatography/tandem mass spectrometry (HRGC/MS/MS) and high‐resolution gas chromatography/triple mass spectrometry (HRGC/MS3) in a quadrupole ion trap, equipped with an external ion source, is presented. MS/MS involves a typical four‐step process, namely ionization, parent ion isolation, collision‐induced dissociation (CID) and mass analysis of the daughter ions. For the MS3 experiment, the MS/MS scan function is used with the addition of selected daughter ion isolation, their CID and the mass analysis of second‐generation product ions called ‘grand‐daughter ions.’ For both methods, the energies necessary for the CID of the 17 PCDD/Fs were determined and optimized using multiple scan functions with different CID amplitudes. The CID efficiency, defined as the signal ratio of fragment ions detected from the major dissociation channels to molecular ions isolated, was 1.15–2.40 V for parent ion dissociation (MS/MS) and 1.05–1.50 V for daughter ion dissociation (MS3) and for all the chloro congeners. The same sensitivity (1 pg µl−1) can be reached with both the MS/MS and MS3 methods and linear responses were obtained between 1 and 100 pg µl−1 injected. Copyright © 2001 John Wiley & Sons, Ltd.
Structure characterization of flavonoid O‐diglycosides by positive and negative nano‐electrospray ionization ion trap mass spectrometry
Authors: Cuyckens Filip , Rozenberg Raoul , de Hoffmann Edmond , Claeys Magda 
Published: August 2002

AbstractIsomeric flavonoid O‐diglycosides were analyzed by positive and negative nano‐electrospray ionization (ESI) ion trap mass spectrometry (ITMS) in order to evaluate whether the two most common interglycosidic linkage types, i.e. 1 → 2 and 1 → 6, found for glycosides containing a rhamnosylglucose glycan part can be differentiated. In the positive ion mode the degree of internal glucose residue loss was found to be strongly dependent on the aglycone type and was very pronounced for aglycones of the flavanone type. The relative abundance of the Y‐type ions formed by fragmentation at glycosidic bonds only allows one to infer the interglycosidic linkage types in the case of flavone O‐diglycosides. In contrast, the negative ion mode makes a clear differentiation between a rutinoside (1 → 6) and a neohesperidoside (1 → 2) glycan residue possible for all aglycone types. The neohesperidose‐containing compounds could be characterized by additional product ions. When the compounds were dissolved in pure methanol a molecular radical ion was found to be the base peak in nano‐ESI. Copyright © 2001 John Wiley & Sons, Ltd.
A B‐TOF mass spectrometer for the analysis of ions with extreme high start‐up energies
Authors: Lezius M. 
Published: August 2002

AbstractWeak magnetic deflection is combined with two acceleration stage time‐of‐flight mass spectrometry and subsequent position‐sensitive ion detection. The experimental method, called B‐TOF mass spectrometry, is described with respect to its theoretical background and some experimental results. It is demonstrated that the technique has distinct advantages over other approaches, with special respect to the identification and analysis of very highly energetic ions with an initially large energy broadening (up to 1 MeV) and with high charge states (up to 30+). Similar energetic targets are a common case in intense laser–matter interaction processes found during laser ablation, laser–cluster and laser–molecule interaction and fast particle and x‐ray generation from laser‐heated plasma. Copyright © 2002 John Wiley & Sons, Ltd.
Sequence evolution and cross‐reactive antibody responses to hypervariable region 1 in acute hepatitis C virus infection*
Authors: Hjalmarsson Sandra , Blomberg Jonas , Grillner Lena , Pipkorn Rüdiger , Allander Tobias 
Published: August 2002

AbstractHepatitis C virus (HCV) infection may result in acute resolving or chronic infection. Patients that clear the infection have a more vigorous cellular immune response and an early humoral response to the hypervariable region 1 (HVR1) of the E2 envelope protein. To analyse further the properties of the early anti‐HVR1 response, cross‐reactivity of anti‐HVR1 responses was assessed in five patients with acute HCV infection, who were infected by the same virus strain during a nosocomial outbreak . The sequence evolution of HVR1 was examined in sequential serum samples up to 37 months post infection. Peptides were synthesised corresponding to the obtained HVR1 sequences and unrelated HVR1 sequences, and antibody reactivity to the peptides in sequential sera was investigated by ELISA. The results suggest an association between specific gaps in humoral immunity and the HVR1 sequence evolution during early infection. Possible interpretations of this phenomenon include immune escape mechanisms or suppression of specific anti‐HVR1 antibodies. J. Med. Virol. 64:117–124, 2001. © 2001 Wiley‐Liss, Inc.
Genetic analysis of recent Taiwanese isolates of a variant of coxsackievirus A24
Authors: Lin Kuei‐Hsiang , Chern Chi‐Liang , Chu Pei‐Yu , Chang Cheng‐Hsien , Wang Heng‐Lin , Sheu Min‐Muh , Huang Wen‐Loong , Pongsuwanna Yaowapa , Yamamoto Seigo , Yoshino Syuji , Ishiko Hiroaki , Takeda Naokazu 
Published: August 2002

AbstractEpidemics of acute hemorrhagic conjunctivitis (AHC) caused by a variant of coxsackievirus A24 (CA24v) reappeared in Taiwan in 1990 and 1994, following the first two epidemics of 1985–86 and 1988–89. To analyze the genetic diversity of recent CA24v in Taiwan, 7 Taiwanese strains isolated during the 1990–94 period were studied together with one Japanese and two Thai strains isolated in 1993. A fragment of 674 nucleotides between the carboxy terminal 3A and the amino terminal 3D polymerase, including the entire 3C protease (3Cpro), was amplified by a reverse transcription‐polymerase chain reaction (RT‐PCR) and the nucleotide sequences were determined. In the 549 nucleotides (183 amino acids) of the entire 3Cpro, we found nucleotide differences at 80 positions between 10 strains and the prototype strain, EH24/70, one of the earliest strains of CA24v. Most of the nucleotide changes were synonymous substitutions and only nine amino acid changes were found. The nucleotide sequence homologies among 71 strains worldwide were 88–100%. These 71 nucleotide sequences were then analyzed by Neighbor‐joining method and phylogenetically separated into three distinct genotypes. Genotype I consisted of early strains isolated in 1970–71 from Singapore and Hong Kong. Genotype II included isolates from Singapore and Thailand obtained in 1975. Genotype III comprised strains from the eastern hemisphere isolated in 1985–94 from Japan, Taiwan, China, Hong Kong, Thailand, Singapore, Pakistan and Ghana. They were further divided chronologically into six clusters. The recent isolates from Taiwan obtained in 1985/1986, 1988/1989 and 1990–94 were classified into genotype III Clusters 1, 5, and 6 respectively. The evolutionary rate was re‐estimated to be 3 × 10− 3 30 years after the emergence of the virus. J. Med. Virol. 64:269–274, 2001. © 2001 Wiley‐Liss, Inc.