bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coumestrol promotes proliferation and osteoblastic differentiation in rat bone marrow stromal cells
Authors: Wu Xiao‐tao , Wang Bin , Wei Ji‐nan 
Published: January 2009

AbstractAlthough the effects of coumestrol on osteoblasts and osteoclasts can be summarized as increasing the bone density and preventing bone resorption, direct and detailed effects of coumestrol on bone marrow stromal cells remain obscure. In the present study, the effects of coumestrol on proliferation and osteoblastic differentiation of rat bone marrow stromal cells (BMSCs) have been investigated; the regulative effect of coumestrol on BMSCs and skeletal system has also been discussed. The results showed that treatment with coumestrol increased cellular activities (analyzed by MTT assay), alkaline phosphatase (ALP), type I collagen and osteocalcin (OCN) activity as well as the protein and gene expression of OPG, gene expression ratio of OPG/RANKL and gene expression of estrogen receptor α(ERα). These results demonstrate that phytoestrogen coumestrol has a direct enhancing effect on the proliferation and osteogenic differentiation of bone marrow stromal cells, which would lead to stimulation of bone formation, and it can also protect the whole skeletal system by regulating OPG/RANKL expression, and these effects may be mediated by ERα. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The influence of chromatic components on extended depth of field imaging
Authors: Navas Javier , Martín Joaquín 
Published: January 2009

AbstractThe analysis of variance is one of the most commonly used algorithms for detecting focalized zones in digital images and is an entry point to extended focalization techniques beyond those established by optical laws. This article analyses the dependence of the red, green, and blue (RGB) and lightness, hue, and saturation (LHS) components when used as the basis for applying an algorithm to obtain images with extended depth of field. Also, an algorithm developed by the authors is described and the dependence of the final result is shown according to the chromatic components used as the variables. Finally, a methodology is defined based on the study of second variance in relation to the number of images and pixels of the chromatic coordinates to decide which to use as the basis for the calculation. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
Detection of pollen grains in multifocal optical microscopy images of air samples
Authors: Landsmeer Sander H. , Hendriks Emile A. , de Weger Letty A. , Reiber Johan H.C. , Stoel Berend C. 
Published: January 2009

AbstractPollen is a major cause of allergy and monitoring pollen in the air is relevant for diagnostic purposes, development of pollen forecasts, and for biomedical and biological researches. Since counting airborne pollen is a time‐consuming task and requires specialized personnel, an automated pollen counting system is desirable. In this article, we present a method for detecting pollen in multifocal optical microscopy images of air samples collected by a Burkard pollen sampler, as a first step in an automated pollen counting procedure. Both color and shape information was used to discriminate pollen grains from other airborne material in the images, such as fungal spores and dirt. A training set of 44 images from successive focal planes (stacks) was used to train the system in recognizing pollen color and for optimization. The performance of the system has been evaluated using a separate set of 17 image stacks containing 65 pollen grains, of which 86% was detected. The obtained precision of 61% can still be increased in the next step of classifying the different pollen in such a counting system. These results show that the detection of pollen is feasible in images from a pollen sampler collecting ambient air. This first step in automated pollen detection may form a reliable basis for an automated pollen counting system. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
Mapping of T1‐values and Gadolinium‐concentrations in MRI as indicator of disease activity in luminal Crohn's disease: A feasibility study
Authors: Horsthuis Karin , Nederveen Aart J. , de Feiter Marijn‐Willem , Lavini Cristina , Stokkers Pieter C.F. , Stoker Jaap 
Published: January 2009

AbstractPurposeTo determine the feasibility of T1‐mapping and calculation of Gadolinium‐values in luminal Crohn's Disease (CD).Materials and MethodsNine patients with active CD were included. For each patient disease activity was determined, based on endoscopic and histopathological results. The Crohn's Disease Endoscopic Index of Severity (CDEIS), the Harvey‐Bradshaw index (HBI) and C‐reactive protein (CRP) were also determined as reference standards. T1‐measurements were performed before and after intravenous administration of Gadodiamide in 14 slices in a single breath‐hold using the Look‐Locker (LL) sequence in combination with a segmented three‐dimensional Turbo Field Echo sequence. A Region of Interest (ROI) was drawn around inflamed bowel loops and the mean Gadolinium‐concentration within the ROI was calculated. Gadolinium‐concentrations were compared between patients with mild and marked disease, as determined by the reference standards.ResultsMean Gadolinium‐concentrations were higher in bowel loops of patients with more active disease, as defined by endoscopic and histopathological examination, CRP, and HBI.ConclusionBy using a breath‐hold LL sequence in the bowel quantitative assessment of contrast agent concentration is possible, thus permitting objective evaluation of physiological changes in actively inflamed tissue in an area that suffers from motion problems. J. Magn. Reson. Imaging 2009;29:488–493. © 2009 Wiley‐Liss, Inc.
MR study of the effect of infarct size and location on left ventricular functional and microstructural alterations in porcine models
Authors: Wu Yin , Chan Carmen W. , Nicholls John M. , Liao Songyan , Tse Hung‐Fat , Wu Ed X. 
Published: January 2009

AbstractPurposeTo investigate the effect of infarct size and location on left ventricular (LV) functional and microstructural alterations in well‐established porcine models.Materials and MethodsMyocardium infarction was induced in mini‐pigs at apical septum (Group 1, n = 6) or basal lateral wall (Group 2, n = 6) by permanent occlusion of the left anterior descending or left circumflex coronary artery, respectively. In vivo cardiac magnetic resonance (CMR) was performed 4 and 13 weeks later. Hearts were then excised and examined by ex vivo diffusion tensor imaging (DTI) for myocardium structural changes in infarct, adjacent and remote regions.ResultsLV ejection fractions correlated negatively with infarct sizes. Between week 4 and 13, Group 1 exhibited more changes in end‐systolic volume, LV mass, and ejection fraction, although it showed a smaller infarct volume percentage. Ex vivo results revealed the decreased water diffusion fractional anisotropy and increased diffusivities in infarct region in correlation with infarct size, but with no significant difference between the two groups. However, LV myocardial double‐helical fiber architecture was found to alter in Group 1, shifting more towards left‐handed direction as compared to controls.ConclusionPostinfarct LV functional and structural remodeling is affected by both infarct size and location. J. Magn. Reson. Imaging 2009;29:305–312. © 2009 Wiley‐Liss, Inc.
Relative apparent diffusion coefficient: Determination of reference site and validation of benefit for detecting metastatic lymph nodes in uterine cervical cancer
Authors: Park Sang Ok , Kim Jeong Kon , Kim Kyoung Ah , Park Bum‐Woo , Kim Namkug , Cho Gyunggoo , Choi Hyuk Jae , Cho Kyoung‐Sik 
Published: January 2009

AbstractPurposeTo determine the reference site for relative apparent diffusion coefficient (rADC) and to evaluate the benefit of rADC for detecting metastatic lymph nodes in uterine cervical cancer.Materials and MethodsTwo observers independently measured ADCs in the spleen, liver, renal cortex, lumbar spine, lumbar spinal cord, and gluteus maximus on diffusion‐weighted images (b value, 0 and 1000 mm/sec2) in 50 patients. The reference site for rADC was determined using the intra‐ and interobserver coefficient of variation (CV) of ADC in these organs. rADC was calculated by ADClesion/ADCreference site. The benefit of rADC over ADC was validated by comparing the area under the receiver operating curve for identifying metastatic lymph nodes in uterine cervical cancer in 130 patients.ResultsThe renal cortex was determined to be the reference site for rADC, as its CVs (intraobserver, 5%–7%; interobserver, 5%) were less than those of the other organs (P < 0.05). The ADC and rADC of metastatic lymph nodes (n = 29, ADC, 0.7483 × 10−3 mm2/sec; rADC, 0.3832) were less than those of nonmetastatic lymph nodes (n = 229, ADC, 0.9960 × 10−3 mm2/sec; rADC, 0.5383) (P < 0.05). The area under the receiver operating characteristics curve for differentiating metastatic from nonmetastatic lymph nodes was greater for rADC (0.914; 95% confidence interval [CI], 0.872–0.945) than for ADC (0.872; 95% CI, 0.825–0.910) (P = 0.007).ConclusionThe renal cortex is an appropriate reference site for rADC and rADC may improve the accuracy for diagnosing metastatic lymph nodes in uterine cervical cancer. J. Magn. Reson. Imaging 2009;29:383–390. © 2009 Wiley‐Liss, Inc.
Comparison of diffusion‐weighted MRI and 2‐[fluorine‐18]‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography (FDG‐PET) for detecting primary colorectal cancer and regional lymph node metastases
Authors: Ono Ken , Ochiai Reiji , Yoshida Tsuyoshi , Kitagawa Mami , Omagari Junichi , Kobayashi Hisashi , Yamashita Yasuyuki 
Published: January 2009

AbstractPurposeTo examine the usefulness of diffusion‐weighted MRI (DW‐MRI) for the detection of both primary colorectal cancer and regional lymph node metastases, and compare its performance with 2‐[fluorine‐18]‐fluoro‐2‐deoxy‐D‐glucose positron emission tomography (FDG‐PET) in the same patients.Materials and MethodsWe studied 25 patients with known colorectal cancer. All underwent both DW‐MRI and FDG‐PET studies. The images were retrospectively assessed by visual inspection and the imaging findings were compared with histopathological findings on surgical specimens.ResultsOf the 27 primary colorectal lesions surgically excised in 25 patients, 23 (85.2%) were true‐positive on both DW‐MRI and FDG‐PET. Two cancers were false‐negative on DW‐MRI but true‐positive on FDG‐PET, and two were false‐negative on both DW‐MRI and FDG‐PET. With respect to the detectability of metastatic lymph nodes, DW‐MRI and FDG‐PET manifested a sensitivity of 80% (8/10) and 30.0% (3/10), a specificity of 76.9% (10/13) and 100% (13/13), and an accuracy of 78.3% (18/23) and 69.6% (16/23), respectively.ConclusionDW‐MRI is inferior to FDG‐PET for the detection of primary lesions, but superior for the detection of lymph node metastases. J. Magn. Reson. Imaging 2009;29:336–340. © 2009 Wiley‐Liss, Inc.
Prediction of locally recurrent prostate cancer after radiation therapy: Incremental value of 3T diffusion‐weighted MRI
Authors: Kim Chan Kyo , Park Byung Kwan , Lee Hyun Moo 
Published: January 2009

AbstractPurposeTo prospectively evaluate the incremental value of diffusion‐weighted imaging (DWI) with apparent diffusion coefficient (ADC) maps in addition to T2‐weighted imaging (T2WI) for predicting locally recurrent prostate cancer in patients with biochemical failure after radiation therapy.Materials and MethodsThirty‐six consecutive patients with an increased prostate‐specific antigen level after radiation therapy underwent 3T MRI followed by transrectal biopsy. The MRI findings and biopsy results were correlated in sextant prostate sectors of peripheral zones (PZs). Two radiologists in consensus reviewed T2WI and combined T2WI and DWI with ADC maps, and rated the likelihood of recurrent cancer on a five‐point scale. ADC values were calculated for recurrent cancer and benign tissue.ResultsOf 216 sectors, 65 prostate sectors (30%) were positive for cancer in 18 patients. For predicting recurrent cancer, combined T2WI and DWI showed a greater sensitivity compared to T2WI (P < 0.001). A significantly greater area under the receiver operating characteristics curve (Az) was determined for combined T2WI and DWI (Az = 0.879, P < 0.01) as compared to T2WI (Az = 0.612). Mean ADC values between recurrent cancer and benign tissue showed a statistically significant difference (P < 0.01).ConclusionFor predicting locally recurrent prostate cancer after radiation therapy, the use of combined T2WI and DWI showed a better diagnostic performance compared to T2WI. J. Magn. Reson. Imaging 2009;29:391–397. © 2009 Wiley‐Liss, Inc.
Evaluation of measurement uncertainties in human diffusion tensor imaging (DTI)‐derived parameters and optimization of clinical DTI protocols with a wild bootstrap analysis
Authors: Zhu Tong , Liu Xiaoxu , Gaugh Michelle D. , Connelly Patrick R. , Ni Hongyan , Ekholm Sven , Schifitto Giovanni , Zhong Jianhui 
Published: January 2009

AbstractPurposeTo quantify measurement uncertainties of fractional anisotropy, mean diffusivity, and principal eigenvector orientations in human diffusion tensor imaging (DTI) data acquired with common clinical protocols using a wild bootstrap analysis, and to establish optimal scan protocols for clinical DTI acquisitions.Materials and MethodsA group of 13 healthy volunteers were scanned using three commonly used DTI protocols with similar total scan times. Two important parameters—the number of unique diffusion gradient directions (NUDG) and the ratio of the total number of diffusion‐weighted (DW) images to the total number of non‐DW images (DTIR)—were analyzed in order to investigate their combined effects on uncertainties of DTI‐derived parameters, using results from both the Monte Carlo simulation and the wild bootstrap analysis of uncertainties in human DTI data.ResultsThe wild bootstrap analysis showed that uncertainties in human DTI data are significantly affected by both NUDG and DTIR in many brain regions. These results agree with previous predictions based on error‐propagations as well as results from simulations.ConclusionOur results demonstrate that within a clinically feasible DTI scan time of about 10 minutes, a protocol with number of diffusion gradient directions close to 30 provides nearly optimal measurement results when combined with a ratio of the total number of DW images over non‐DW images equal to six. Wild bootstrap can serve as a useful tool to quantify the measurement uncertainty from human DTI data. J. Magn. Reson. Imaging 2009;29:422–435. © 2009 Wiley‐Liss, Inc.
Interleaved T1 and T2 relaxation time mapping for cardiac applications
Authors: Blume Ulrike , Lockie Timothy , Stehning Christian , Sinclair Stephen , Uribe Sergio , Razavi Reza , Schaeffter Tobias 
Published: January 2009

AbstractPurposeTo diagnose acute myocardial infarction (MI) with MRI, T1‐weighted and T2‐weighted images are required to detect necrosis and edema. The calculation of both T1 and T2 maps can be relevant for quantitative diagnosis. In this work, we present a simultaneous quantification of T1‐T2 relaxation times of a short‐axis view of the heart in a single scan.Materials and MethodsAn electrocardiograph (ECG)‐triggered, navigator‐gated, interleaved T1 and T2 mapping sequence was implemented for the quantification of the T1 and T2 values of phantoms, healthy volunteers, and three patients with acute MI. The proposed acquisition scheme consisted of an interleaved two‐dimensional (2D) steady‐state free precession (SSFP) sequence with three different modules: an inversion‐recovery (IR) sequence with multiple time delays, followed by a delay of one cardiac cycle for magnetization recovery and a T2‐preparation pulse with multiple echo‐times for T2 quantification.ResultsMeasurements of in vivo relaxation times were in good agreement with literature values. The interleaved sequence was able to measure T1 and T2 relaxation times of the myocardium.ConclusionThe interleaved sequence acquires data for the calculation of T1 and T2 maps in only one scan without the need for registration. This technique has the potential to differentiate between acute and chronic MI by estimating the concentration of gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) in the necrotic tissue and to assess the extent of edema from T2 maps. J. Magn. Reson. Imaging 2009;29:480–487. © 2009 Wiley‐Liss, Inc.
Contiguous‐slice zonally oblique multislice (CO‐ZOOM) diffusion tensor imaging: Examples of in vivo spinal cord and optic nerve applications
Authors: Dowell Nicholas G. , Jenkins Thomas M. , Ciccarelli Olga , Miller David H. , Wheeler‐Kingshott Claudia A.M. 
Published: January 2009

AbstractPurposeTo describe and demonstrate a new technique that allows diffusion tensor imaging of small structures such as the spinal cord (SC) and optic nerve (ON) with contiguous slices and reduced image distortions using a narrow field of view (FOV).Materials and MethodsImages were acquired with a modified single‐shot echo‐planar imaging (EPI) sequence that contains a refocusing radio frequency (RF) pulse in the presence of the phase‐encoding (rather than slice‐select) gradient. As a result, only a narrow volume may be both excited and refocused, removing the problem of signal aliasing for narrow FOVs. Two variants of this technique were developed: cardiac gating is included in the study of the SC to reduce pulsation artifacts, whereas inversion‐recovery (IR) cerebrospinal fluid (CSF) suppression is utilized in the study of the ON to eliminate partial volume effects. The technique was evaluated with phantoms, and mean diffusivity (MD) and fractional anisotropy (FA) measurements were made in the SC and ON of two healthy volunteers.ResultsThe technique provides contiguous‐slice, reduced‐FOV images that do not suffer from aliasing and have reduced magnetic susceptibility artifacts. MD and FA values determined here lie within the ranges quoted in the literature.ConclusionContiguous‐slice zonally orthogonal multislice (CO‐ZOOM‐EPI is a new technique for diffusion‐weighted imaging of small structures such as the ON and SC with high resolution and reduced distortions due to susceptibility variations. This technique is able to acquire contiguous slices that may allow further nerve‐tracking analyses. J. Magn. Reson. Imaging 2009;29:454–460. © 2009 Wiley‐Liss, Inc.
T2 detection of tumor invasion within segmented components of glioblastoma multiforme
Authors: McMillan Kathryn M. , Ehtesham Moneeb , Stevenson Charles B. , Edgeworth Michael L. , Thompson Reid C. , Price Ronald R. 
Published: January 2009

AbstractPurposeTo use T2‐weighted images to detect tumor invasion when comparing normal individuals to groups of gliomablastoma multiforme (GBM) patients with varying levels of CXCR4, a chemokine receptor that promotes tumor migration.Materials and MethodsT2‐weighted images were acquired preoperatively in 22 treatment‐naïve GBM patients. Two groups were formed based on the expression levels of CXCR4. A third group of normal volunteers was used for comparison. Each image was segmented to obtain four different clusters for tissue types identified as white matter, basal ganglia, gray matter/edema and cerebrospinal fluid (CSF)/tumor. Signal intensity histograms were formed for each cluster and compared between groups.ResultsIn every cluster the GBM groups displayed significantly higher standard deviations of intensity distributions when compared to normal subjects. Significant differences in skewness were found between normal subjects and GBM patients in the white matter, basal ganglia, and CSF/tumor. Further, when the two groups of GBM patients were compared the CXCR4‐high group was found to have a significant shift in the median intensity values in the cluster containing gray matter and peritumoral edema.ConclusionT2 signal intensity histograms in normal subjects differ significantly from those obtained from GBM groups, suggesting widespread dissemination of disease. J. Magn. Reson. Imaging 2009;29:251–257. © 2009 Wiley‐Liss, Inc.
Spleen R2 and R2* in iron‐overloaded patients with sickle cell disease and thalassemia major
Authors: Brewer Casey J. , Coates Thomas D. , Wood John C. 
Published: January 2009

AbstractPurposeTo evaluate the magnetic properties of the spleen in chronically transfused, iron‐overloaded patients with sickle cell disease (SCD) and thalassemia major (TM) and to compare splenic iron burdens to those in the liver, heart, pancreas, and kidneys.Materials and MethodsA retrospective analysis of 63 TM and 46 SCD patients was performed. Spleen R2 and R2* values were calculated from spin‐echo and gradient‐echo images collected between April 2004 and September 2007.ResultsThe spleen showed a different R2–R2* relationship than that previously established for the liver. At high iron concentrations (R2* > 300 Hz), spleen R2 was lower than predicted for liver. The proportion of splenic to hepatic iron content was greater in SCD patients compared with TM patients (23.8% vs. 13.8%). A weak association was found between splenic and liver iron—this association was stronger in SCD patients. Little correlation was found between splenic iron and extrahepatic R2* values.ConclusionFor spleen and liver tissue with the same R2* value, splenic R2 was significantly lower than hepatic R2, particularly for R2* > ≈300 Hz. Splenic iron levels have little predictive value for R2* values of heart, pancreas, and kidney. J. Magn. Reson. Imaging 2009;29:357–364. © 2009 Wiley‐Liss, Inc.
Evaluation of the translational and rotational forces acting on a highly ferromagnetic orthopedic spinal implant in magnetic resonance imaging
Authors: McComb Christie , Allan David , Condon Barrie 
Published: January 2009

AbstractPurposeTo assess the translational and rotational forces acting on a highly ferromagnetic orthopedic spinal implant in 1.5T and 3.0T magnetic resonance (MR) systems.Materials and MethodsThe translational forces and rotational forces, or torques, acting on the implant were measured using existing methods and assessed using the guidelines produced by the American Society for Testing and Materials (ASTM).ResultsThe measured translational forces were many times greater than for any other orthopedic implant previously recorded in the literature and, based on deflection angle criteria, would be considered unsafe in both MR systems. However, due to the rigid fixation of orthopedic implants in bone, implant migration is considered highly unlikely. Several constituent components of the implant were subjected to large torques, in some cases an order of magnitude greater than the corresponding torque due to gravity. However, the counterbalancing effect of the configuration of the combined implant results in a net torque that is less than the torque due to gravity.ConclusionThe translational and rotational forces acting on the implant in both 1.5T and 3.0T MR systems are substantial, but based on theoretical considerations are unlikely to result in implant migration or rotation. J. Magn. Reson. Imaging 2009;29:449–453. © 2009 Wiley‐Liss, Inc.