bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion‐weighted imaging of the liver: Optimizing b value for the detection and characterization of benign and malignant hepatic lesions
Authors: Goshima Satoshi , Kanematsu Masayuki , Kondo Hiroshi , Yokoyama Ryujiro , Kajita Kimihiro , Tsuge Yusuke , Watanabe Haruo , Shiratori Yoshimune , Onozuka Minoru , Moriyama Noriyuki 
Published: September 2008

AbstractPurposeTo determine the optimal b values required for diffusion‐weighted (DW) imaging of the liver in the detection and characterization of benign and malignant hepatic lesions.Materials and MethodsMR images obtained in 76 patients including 28 malignant hepatic lesions (21 hepatocellular carcinomas and 7 metastases) and 27 benign lesions (12 hemangiomas and 15 cysts) were reviewed. DW‐echo planner images (EPIs; b values with100, 200, 400, and 800 s/mm2) were reviewed solely first, and then with T2‐weighted EPIs (b = 0 s/mm2).ResultsSensitivity for malignant lesions (74%) was highest on DW‐EPIs with b value of 100 s/mm2 and T2‐weighted EPIs combined (P < 0.05), and sensitivity for benign lesions (87%) was highest on DW‐EPIs with b value of 800 s/mm2 and T2‐weighted EPIs (P < 0.05). Specificities were comparably high for all sequences. The Az values for malignant lesions were 0.94, 0.90, 0.87, and 0.89, and those for benign lesions were 0.91, 0.89, 0.87, and 0.94 on DW‐EPIs with b values of 100, 200, 400, and 800 and T2‐weighted EPIs combined, respectively. Hepatic cysts were clearly distinguished with the cutoff ADC value of 2.5 ×10−3 mm2/s using a b value of 400 s/mm2 or greater.ConclusionDW‐EPIs with middle b values were not required in the detection and characterization of benign and malignant hepatic lesions. J. Magn. Reson. Imaging 2008;28:691–697. © 2008 Wiley‐Liss, Inc.
Diffusion tensor imaging and fiber tractography of C6 rat glioma
Authors: Asanuma Taketoshi , Doblas Sabrina , Tesiram Yasvir A. , Saunders Debra , Cranford Rebecca , Pearson Jamie , Abbott Andrew , Smith Nataliya , Towner Rheal A. 
Published: September 2008

AbstractPurposeTo apply diffusion tensor images using 30 noncollinear directions for diffusion‐weighted gradient schemes to characterize diffusion tensor imaging (DTI) features associated with C6 glioma‐bearing rat brains, and ideally visualize fiber tractography datasets.Materials and MethodsFiber tractographies of normal male Fischer 344 rat brains were constructed from DTI datasets acquired with a 30 noncollinear diffusion gradient scheme. Cultured C6 cell were intracranially injected into the cortex of male Fischer 344 rats. The time course of the tumor growth was monitored with DTI and fiber tractography using diffusion‐weighting gradients in 30 noncollinear directions.ResultsFiber tractographies through the corpus callosum (CC) were easily visualized with the 30‐direction gradient scheme, and the fiber trajectories of the motor cortex and striatum were well represented in normal rats. Fiber tractography indicated that the neuronal fibers of the CC were compressed or disappeared by growing C6 glioma, which affected surrounding brain tissue.ConclusionWe have demonstrated in this study that fiber tractography with the 30 noncollinear diffusion gradient scheme method can be used to help provide a better understanding regarding the influence of a tumor on the surrounding regions of normal brain tissue in vivo. J. Magn. Reson. Imaging 2008;28:566–573. © 2008 Wiley‐Liss, Inc.
A dual‐projection respiratory self‐gating technique for whole‐heart coronary MRA
Authors: Lai Peng , Larson Andrew C. , Bi Xiaoming , Jerecic Renate , Li Debiao 
Published: September 2008

AbstractPurposeTo investigate the accuracy of a dual‐projection respiratory self‐gating (DP‐RSG) technique in dynamic heart position measurement and its feasibility for free‐breathing whole‐heart coronary MR angiography (MRA).Materials and MethodsA DP‐RSG method is proposed to enable accurate direct measurement of heart position by acquiring two whole‐heart projections. On 14 volunteers we quantitatively evaluated the efficacy of DP‐RSG by comparison with diaphragmatic navigator (NAV) and single‐projection‐based respiratory self‐gating (SP‐RSG) methods. For DP‐RSG we also compared center‐of‐mass and two profile‐matching algorithms in deriving heart motion. Coronary imaging was conducted on eight volunteers based on retrospective gating to preliminarily validate the effectiveness of DP‐RSG for whole‐heart coronary MRA. Comparison of vessel delineation was performed between images reconstructed using different gating methods.ResultsThe quantitative evaluation shows that DP‐RSG more accurately tracks heart motion than NAV with all gating window (GW) values and SP‐RSG approaches with GW ≥2.5 mm and profile‐matching algorithms are more reliable for motion derivation than center‐of‐mass calculations with GW ≥1.0 mm. Whole‐heart coronary MRA studies demonstrate the feasibility of using DP‐RSG to improve overall delineation of the coronary arteries.ConclusionDP‐RSG is a promising approach to better resolve respiratory motion for whole‐heart coronary MRA compared to conventional NAV and SP‐RSG. J. Magn. Reson. Imaging 2008;28:612–620. © 2008 Wiley‐Liss, Inc.
Dynamic changes in murine vessel geometry assessed by high‐resolution magnetic resonance angiography: A 9.4T study
Authors: Jacoby Christoph , Böring Yang Chul , Beck Andreas , Zernecke Alma , Aurich Volker , Weber Christian , Schrader Jürgen , Flögel Ulrich 
Published: September 2008

AbstractPurposeTo establish high‐resolution magnetic resonance angiography (MRA) protocols to monitor and quantify dynamic changes of vascular remodeling in pathologic mouse models.Materials and MethodsTime‐of‐flight (TOF) MRA of murine vessels was performed at 9.4T to monitor temporal alterations in the vessel structure in two frequently used injury models (wire denudation of carotid artery and femoral artery occlusion). Quantification of vessel morphology was performed with the use of in‐house‐developed software and validated by estimation of inter‐ and intraobserver variabilities and reproducibility, and by correlation with histological data.ResultsMRA‐based volume determination exhibited low intra‐ and interobserver variabilities and high reproducibility. Furthermore, good correlations with histological data were found four weeks after injury (R2 = 0.970). Two high‐resolution image series are presented to demonstrate the applicability of the technique: 1) the time course of a vessel stenosis that reopens by thrombus recanalization, and 2) the continuous restoration of blood flow by collateral vessel formation during arteriogenesis after induction of hindlimb ischemia.ConclusionWe describe high‐resolution MRA imaging protocols that are suitable for sensitively measuring the extent and time course of changes in vessel morphology in mice in a repetitive manner without any contrast agent. This methodology provides a reliable tool for noninvasive monitoring of vascular lesion development or neovascularization in transgenic mice. J. Magn. Reson. Imaging 2008;28:637–645. © 2008 Wiley‐Liss, Inc.
High‐spatial‐resolution three‐dimensional MR cholangiography using a high‐sampling‐efficiency technique (SPACE) at 3T: Comparison with the conventional constant flip angle sequence in healthy volunteers
Authors: Arizono Shigeki , Isoda Hiroyoshi , Maetani Yoji S. , Hirokawa Yuusuke , Shimada Kotaro , Nakamoto Yuji , Togashi Kaori 
Published: September 2008

AbstractPurposeTo evaluate the image quality of high‐spatial‐resolution three‐dimensional magnetic resonance cholangiography (MRC) with a high‐sampling‐efficiency technique (sampling perfection with application optimized contrasts using different flip angle evolutions [SPACE]) in comparison with a conventional constant flip angle (FA) sequence at 3T.Materials and MethodsEighteen volunteers were examined on a 3T MR unit using MRC imaging performed with three different free‐breathing three‐dimensional T2‐weighted turbo spin‐echo (TSE) sequences: 1) SPACE (spatial resolution, 1.1 × 1.0 × 0.84 mm), 2) constant FA (1.1 × 1.0 × 0.84 mm), and 3) SPACE at a higher resolution (SPACE HR; 1.0 × 0.9 × 0.644 mm). A five‐point scale was used to compare overall image quality and visualization of the third branches of the bile duct (B2, B6, and B8). Depictions of cystic duct insertion and the highest order of bile duct visible were also compared.ResultsMRC with SPACE and SPACE HR sequences produced significantly better overall image quality than the constant FA sequence. In all analyses of duct visibility, SPACE and SPACE HR sequences showed higher scores than the constant FA sequence.ConclusionHigh‐resolution three‐dimensional MRC with SPACE at 3T allows high‐quality imaging of the biliary tract, and has the ability to depict nondilated intrahepatic bile ducts (IHBD) in healthy volunteers. J. Magn. Reson. Imaging 2008;28:685–690. © 2008 Wiley‐Liss, Inc.
Navigator‐triggered prospective acquisition correction (PACE) technique vs. conventional respiratory‐triggered technique for free‐breathing 3D MRCP: An initial prospective comparative study using healthy volunteers
Authors: Morita Satoru , Ueno Eiko , Suzuki Kazufumi , Machida Haruhiko , Fujimura Mikihiko , Kojima Shinya , Hirata Masami , Ohnishi Takahiro , Imura Chiaki 
Published: September 2008

AbstractPurposeTo confirm the superiority of the navigator‐triggered prospective acquisition correction (PACE) technique over the conventional respiratory‐triggered (RESP) technique, something that has been perceived experimentally but without definite evidence, for free‐breathing three‐dimensional (3D) magnetic resonance cholangiopancreatography (MRCP) using healthy volunteers.Materials and MethodsFree‐breathing 3D turbo spin‐echo MRCP using both PACE and RESP techniques were prospectively performed on 25 healthy volunteers. Quantitative analyses of acquisition time, signal‐to‐noise ratio, contrast‐to‐noise ratio, and contour sharpness index of each segment of the pancreaticobiliary tree were compared using the paired t‐test. Qualitative analyses on a five‐point scale (1, excellent; 5, poor) scored by two independent radiologists were compared using the Wilcoxon signed‐rank test.ResultsThe subjective image quality and contour sharpness index of each segment of the PACE technique were found to be significantly better than those for RESP (P < 0.05). No significant difference was observed with regard to signal‐to‐noise and contrast‐to‐noise ratios except for the pancreatic duct. No significant difference in acquisition times between PACE and RESP techniques was observed.ConclusionWe confirmed the superiority of the image quality of the PACE technique compared to conventional RESP technique for free‐breathing 3D MRCP in healthy volunteers. J. Magn. Reson. Imaging 2008;28:673–677. © 2008 Wiley‐Liss, Inc.
Evaluation of locally recurrent pelvic malignancy: Performance of T2‐ and diffusion‐weighted MRI with image fusion
Authors: Nishie Akihiro , Stolpen Alan H. , Obuchi Masao , Kuehn David M. , Dagit Aaron , Andresen Kelli 
Published: September 2008

AbstractPurposeTo evaluate the performance of T2‐ and diffusion‐weighted magnetic resonance imaging (MRI) with image fusion for detection of locally recurrent pelvic malignancy.Materials and MethodsThe study group consisted of 28 patients (27 female, 1 male) who underwent pelvic MRI at 1.5 T after treatment of pelvic malignancy. MR images were reviewed independently by three blinded readers. The performance of the four sequences for detecting local recurrence was evaluated using receiver operating characteristic analysis: T2‐weighted fast spin‐echo (FSE), diffusion‐weighted echo‐planar imaging (DWI), dynamic contrast‐enhanced (DCE) fat‐suppressed T1‐weighted spoiled gradient echo (SPGR), and T2‐DWI with image fusion, the latter created using OsiriX Medical Imaging Software.ResultsLocal recurrence was confirmed at biopsy in 16 patients. Twelve patients showed no evidence of recurrence on two consecutive MRI studies. The Az value for T2‐DWI with image fusion (0.949) was statistically greater than that for T2‐weighted FSE (0.849) (P < 0.05). The sensitivity and specificity was 87.5% and 47.2%, respectively, for T2‐weighted FSE, 100.0% and 50.0% for DWI, 95.8% and 58.3% for DCE fat‐suppressed T1‐weighted SPGR, and 93.8% and 72.2% for T2‐DWI with image fusion.ConclusionFor depicting locally recurrent pelvic malignancy, T2‐DWI with image fusion outperforms standard T2‐weighted FSE and DWI and is comparable to DCE fat‐suppressed T1‐weighted SPGR. J. Magn. Reson. Imaging 2008;28:705–713. © 2008 Wiley‐Liss, Inc.
Investigation and optimization of parameter accuracy in dynamic contrast‐enhanced MRI
Authors: Cheng Hai‐Ling Margaret 
Published: September 2008

AbstractPurposeTo present a modified pharmacokinetic model for improved parameter accuracy and to investigate the influence of an inaccurate arterial input function (AIF) on dynamic contrast‐enhanced (DCE)‐MRI parameter estimates of the transfer constant (Ktrans), blood volume (vp), and interstitial volume (ve).Materials and MethodsTissue uptake curves were simulated over a large range of physiological values and analyzed for different AIF measurement errors and temporal resolutions. The AIF measurement was assumed to be inaccurate in the bolus amplitude (rapid sampling) or susceptible to unknown temporal offsets (slow sampling with biexponential decay fit).ResultsThe modified model adequately reduces errors in parameter estimates arising from transit time effects. An error in the AIF bolus amplitude results in an inversely proportional error in Ktrans and vp; ve remains robust. More consistent error in Ktrans (≈20% underestimation) was obtained using a biexponential AIF, at the expense of severely underestimating vp.ConclusionWhile an accurate, high temporal resolution AIF is essential for estimating vp, a biexponential AIF acquired at low temporal resolution (<20 seconds) provides robust estimates of ve and results in a Ktrans underestimation comparable to that from a 25% error in the initial AIF bolus amplitude. J. Magn. Reson. Imaging 2008;28:736–743. © 2008 Wiley‐Liss, Inc.
Dynamic contrast‐enhanced (DCE) derived transfer coefficient (ktrans) is a surrogate marker of matrix metalloproteinase 9 (MMP‐9) expression in brain tuberculomas
Authors: Haris Mohammad , Husain Nuzhat , Singh Anup , Awasthi Rishi , Singh Rathore Ram Kishore , Husain Mazhar , Gupta Rakesh K. 
Published: September 2008

AbstractPurposeTo correlate dynamic contrast‐enhanced (DCE) MRI derived perfusion indices with immunohistochemically obtained vascular endothelial growth factor (VEGF) and matrix metalloproteinase‐9 (MMP‐9) in a cellular fraction of brain tuberculomas (BT).Materials and MethodsThirteen BT patients underwent DCE MRI. Perfusion indices (cerebral blood volume [CBV], transfer coefficient [ktrans] and leakage [ve]) maps were generated for the quantitative analysis. The CBV was corrected for the leaky blood–brain barrier (BBB). The relative CBV (rCBV), ktrans, and ve were calculated by placing 10 regions of interest (ROIs) showing the highest values in the lesion. The percentage area of VEGF and percentage area of MMP‐9 and microvessel density (MVD) were quantified from 10 fields per lesion with maximal expression of the excised BT. Pearson correlation analysis between physiological indices and quantitative VEGF, MMP‐9, and MVD was performed for each ROI.ResultsThe average value of rCBV, ktrans, ve, VEGF, MMP‐9, and MVD were 3.53 ± 0.37, 2.04 ± 0.40 min−1, 0.71 ± 0.09, 12.51 ± 2.56, 18.09 ± 2.06, 10.87 ± 1.99, respectively. The ktrans (r = 0.918, P < 0.001) and ve (r = 0.899, P < 0.001) showed significant correlation with MMP‐9, while rCBV correlated significantly with MVD (r = 0.962, P < 0.001) and VEGF (r = 0.868, P < 0.001).ConclusionWe conclude that the expression of MMP‐9, a marker of BBB disruption and disease activity in BT correlates with DCE‐derived ktrans and thus has the potential to be used as its surrogate marker. J. Magn. Reson. Imaging 2008;28:588–597. © 2008 Wiley‐Liss, Inc.
Agreement between different input image types in brain atrophy measurement in multiple sclerosis using SIENAX and SIENA
Authors: Neacsu Veronica , Jasperse Bas , Korteweg Tijmen , Knol Dirk L. , Valsasina Paola , Filippi Massimo , Barkhof Frederik , Rovaris Marco , Vrenken Hugo 
Published: September 2008

AbstractPurposeTo investigate whether multiple sclerosis (MS) atrophy can be assessed by SIENA and SIENAX software using other image types from MS research protocols than T1‐weighted images without contrast agent, which are not always available.Materials and MethodsWe selected 46 MS patients with identical magnetic resonance imaging (MRI) protocols at two timepoints. We calculated normalized brain volume (NBV) using SIENAX, and percentage brain volume change (PBVC) using SIENA, from T1‐weighted images with and without contrast agent, T2‐weighted images, and (calculated) pseudo‐T1‐weighted images. Relative agreement of the results was assessed using variance component estimation.ResultsRelative agreement with T1‐weighted images without contrast agent was good for T1‐weighted images with contrast agent (ICC = 0.86 for NBV, ICC = 0.77 for PBVC), and reasonably good for pseudo‐T1 and T2‐weighted images (T2: ICC = 0.72 for NBV, 0.58 for PBVC; pseudo‐T1: ICC = 0.68 for NBV, 0.83 for PBVC).ConclusionBrain atrophy can be studied using SIENA and SIENAX if T1‐weighted images without contrast agent are not available. T1‐weighted images with contrast agent should be used if available. Otherwise, pseudo‐T1 and T2‐weighted images seem acceptable and accessible alternatives. The use of these other images will greatly improve research possibilities, especially regarding older datasets. J. Magn. Reson. Imaging 2008;28:559–565. © 2008 Wiley‐Liss, Inc.
Apparent diffusion coefficient values in peripheral and transition zones of the prostate: Comparison between normal and malignant prostatic tissues and correlation with histologic grade
Authors: Tamada Tsutomu , Sone Teruki , Jo Yoshimasa , Toshimitsu Shinya , Yamashita Takenori , Yamamoto Akira , Tanimoto Daigo , Ito Katsuyoshi 
Published: September 2008

AbstractPurposeTo investigate the utility of apparent diffusion coefficient (ADC) values for discriminating tumor in patients with prostate cancer from normal prostatic tissues in healthy adult men, and to identify correlations between ADC and histologic grade of prostate cancer.Materials and MethodsA total of 125 healthy male volunteers (mean age, 60 years; range, 50–86 years) and 90 prostate cancer patients (mean age, 71 years; range, 51–88 years) underwent diffusion‐weighted imaging (DWI) of the prostate with a single‐shot echo‐planar imaging sequence using b‐factors of 0 and 800 sec/mm2. ADC was measured from two locations in the peripheral zone (PZ) and two locations in the central gland (CG) in normal subjects, and tumor locations of PZ or transition zone (TZ) in patients with prostate cancer.ResultsMean ADC values of tumor regions in both PZ (1.02 ± 0.25 × 10−3 mm2/sec) and TZ (0.94 ± 0.21 × 10−3 mm2/sec) were significantly lower than those in the corresponding normal regions (1.80 ± 0.27 × 10−3 mm2/sec and 1.34 ± 0.14 × 10−3 mm2/sec, respectively) (P < 0.0001 each). Furthermore, a significant negative correlation was identified between ADC in PZ cancer and tumor Gleason score (ρ = −0.497, P < 0.0001).ConclusionADC values appear to provide acceptable diagnostic accuracy in both PZ and TZ. J. Magn. Reson. Imaging 2008;28:720–726. © 2008 Wiley‐Liss, Inc.
Evaluation of cardiac biventricular segmentation from multiaxis MRI data: A multicenter study
Authors: Lötjönen Jyrki M.P. , Järvinen Vesa M. , Cheong Benjamin , Wu Edwin , Kivistö Sari , Koikkalainen Juha R. , Mattila Jussi J.O. , Kervinen Helena M. , Muthupillai Raja , Sheehan Florence H. , Lauerma Kirsi 
Published: September 2008

AbstractPurposeTo validate a volumetric biventricular segmentation solution for multiaxis cardiac magnetic resonance (CMR) images.Materials and MethodsThe study population comprised 40 subjects. Biventricular end‐diastolic and ‐systolic phases were segmented from both short‐axis and horizontal long‐axis or transaxial cine CMR images. Segmentation was based on fitting nonrigidly a 3D surface model to multiaxis CMR images. Five segmentations were performed: two manual segmentations by experts, automatic segmentation, and two segmentations where a user was allowed to correct errors in the automatic segmentation for 2 minutes and without time limits. Volumetry, distance measures, and visual grading were used to evaluate the quality of the segmentation.ResultsNo difference was observed between automatic and manual segmentations in volumetric measures of the ventricles. The manual segmentation performed better for left‐ventricular myocardial volume. The distance between surfaces as well as visual analysis did not show differences between automatic and manual segmentation for the endocardial border of the left ventricle but some corrections are needed for the right ventricle.ConclusionFully automatic segmentation produces good results in the assessment of left ventricular volume andendocardial border. Two minutes of user interaction are needed to obtain accurate results for the right ventricle. J. Magn. Reson. Imaging 2008;28:626–636. © 2008 Wiley‐Liss, Inc.
Titchmarsh–Weyl m ‐functions for second‐order Sturm–Liouville problems with two singular endpoints
Authors: Fulton Charles 
Published: September 2008

AbstractIn this paper we consider some cases of Sturm–Liouville problems with two singular endpoints at x = 0 and x = ∞ which have a simple spectrum, and show that the simplicity of the spectrum can be built into the definition of a Titchmarsh–Weyl m ‐function from which the eigenfunction expansion can be constructed. The use of initial conditions at a point interior to the interval (0,∞) is avoided in favor of Frobenius solutions near the regular singular point x = 0. In contrast to the classical theory associated with a regular left endpoint, the growth behaviour of the associated spectral functions can be on the order of λβ for any β ∈ (0,∞). Application of the theory to the Bessel equation on (0,∞) and to the radial part of the separated hydrogen atom on (0,∞) is given. In the case of the hydrogen atom a single Titchmarsh–Weyl m ‐function is obtained which completely describes both the discrete negative spectrum and the continuous positive spectrum. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pharmacological and therapeutic secrets of plant and brain (endo)cannabinoids
Authors: Hanuš Lumír Ondřej 
Published: September 2008

AbstractResearch on the chemistry and pharmacology of cannabinoids and endocannabinoids has reached enormous proportions, with approximately 15,000 articles onCannabis sativa L. and cannabinoids and over 2,000 articles on endocannabinoids. The present review deals with the history of theCannabis sativa L. plant, its uses, constituent compounds and their biogeneses, and similarity to compounds fromRadulaspp. In addition, details of the pharmacology of natural cannabinoids, as well as synthetic agonists and antagonists are presented. Finally, details regarding the pioneering isolation of the endocannabinoid anandamide, as well as the pharmacology and potential therapeutic uses of endocannabinoid congeners are presented. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 2, 213–271, 2009