bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can physical activity modulate pancreatic cancer risk? a systematic review and meta‐analysis
Authors: O'Rorke Michael A. , Cantwell Marie M. , Cardwell Chris R. , Mulholland Helen G. , Murray Liam J. 
Published: October 2009

AbstractNumerous epidemiological studies have examined the association between physical activity and pancreatic cancer; however, findings from individual cohorts have largely not corroborated a protective effect. Among other plausible mechanisms, physical activity may reduce abdominal fat depots inducing metabolic improvements in glucose tolerance and insulin sensitivity, thereby potentially attenuating pancreatic cancer risk. We performed a systematic review to examine associations between physical activity and pancreatic cancer. Six electronic databases were searched from their inception through July 2009, including MEDLINE and EMBASE, seeking observational studies examining any physical activity measure with pancreatic cancer incidence/mortality as an outcome. A random effects model was used to pool individual effect estimates evaluating highest vs. lowest categories of activity. Twenty‐eight studies were included. Pooled estimates indicated a reduction in pancreatic cancer risk with higher levels of total (five prospective studies, RR: 0.72, 95% CI: 0.52–0.99) and occupational activity (four prospective studies, RR: 0.75, 95% CI: 0.59–0.96). Nonsignificant inverse associations were seen between risks and recreational and transport physical activity. When examining exercise intensity, moderate activity appeared more protective (RR: 0.79, 95% CI: 0.52–1.20) than vigorous activity (RR: 0.97, 95% CI: 0.85–1.11), but results were not statistically significant and the former activity variable incorporated marked heterogeneity. Despite indications of an inverse relationship with higher levels of work and total activity, there was little evidence of such associations with recreational and other activity exposures.
Probing the interaction between recombinant human myelin basic protein and caseins using surface plasmon resonance and diffusing wave spectroscopy
Authors: Al‐Ghobashy Medhat A. , Cucheval Aurelie , Williams Martin A. K. , Laible Götz , Harding David R. K. 
Published: October 2009

AbstractAn intrinsically unstructured human myelin basic protein (hMBP) was expressed in the milk of transgenic cows (TGmilk) and found exclusively associated with the casein micellar phase. The interaction between the recombinant protein and milk caseins was investigated using surface plasmon resonance (SPR). An anti‐human myelin basic protein antibody was covalently immobilized to the surface of the sensor chip. Subsequently the interaction between the recombinant protein (captured by this antibody) and caseins was studied in comparison to that noted with its human counterpart. Results showed a calcium‐mediated interaction between the recombinant protein and caseins. The order of magnitude of this interaction was in agreement with the number of phosphorylated residues carried by each type of casein (αs‐ > β‐ > κ‐casein). This selective interaction was not noted between the human protein and milk caseins indicating that the recombinant protein was phosphorylated to a higher extent than the human protein. The obtained results indicated that the co‐expression of the recombinant protein and caseins by the mammary gland along with the recombinant protein's ability to form calcium bridges played a key role in the association of the recombinant human myelin basic protein (rhMBP) with the casein micelles of milk. Despite this association between the recombinant protein and milk caseins, light scattering investigations using diffusing wave spectroscopy (DWS) showed no significant differences between the milks of the transgenic and the non‐transgenic control cows, with respect to both the average micelle size and surface charges. This was attributed to the low expression levels of the recombinant protein in milk. Copyright © 2009 John Wiley & Sons, Ltd.
Cross‐validation of magnetic resonance elastography and ultrasound‐based transient elastography: A preliminary phantom study
Authors: Oudry Jennifer , Chen Jun , Glaser Kevin J. , Miette Véronique , Sandrin Laurent , Ehman Richard L. 
Published: October 2009

AbstractPurpose:To cross‐validate two recent noninvasive elastographic techniques, ultrasound‐based transient elastography (UTE) and magnetic resonance elastography (MRE). As potential alternatives to liver biopsy, UTE and MRE are undergoing clinical investigations for liver fibrosis diagnosis and liver disease management around the world. These two techniques use tissue stiffness as a marker for disease state and it is important to do a cross‐validation study of both elastographic techniques to determine the consistency with which the two techniques can measure the mechanical properties of materials.Materials and Methods:In this study, 19 well‐characterized phantoms with a range of stiffness values were measured by two clinical devices (a Fibroscan and an MRE system based respectively on the UTE and MRE techniques) successively with the operators double‐blinded.Results:Statistical analysis showed that the correlation coefficient was r2 = 0.93 between MRE and UTE, and there was no evidence of a systematic difference between them within the range of stiffnesses examined.Conclusion:These two noninvasive methods, MRE and UTE, provide clinicians with important new options for improving patient care regarding liver diseases in terms of the diagnosis, prognosis, and monitoring of fibrosis progression, as well for evaluating the efficacy of treatment. J. Magn. Reson. Imaging 2009;30:1145–1150. © 2009 Wiley‐Liss, Inc.
Optimization of the contrast dose and injection rates in whole‐body MR angiography at 3.0T
Authors: Waugh Shelley A. , Ramkumar P. Guntur , Gandy Stephen J. , Nicholas R. Stephen , Martin Patricia , Belch Jill J.F. , Struthers Allan D. , Houston J. Graeme 
Published: October 2009

AbstractPurpose:To optimize the contrast agent dose and delivery rate used in a novel whole‐body magnetic resonance angiography (MRA) protocol using a 3.0T MR scanner.Materials and Methods:Six groups of 20 consenting volunteers underwent whole‐body MRA, with each group receiving a different contrast dose and contrast delivery rate. The arterial tree was divided into 16 segments and the image quality at each of the anatomical locations, covering the whole body, was assessed. Qualitative analysis was carried out using a scoring assessment of image quality, and quantitative assessments were performed by measuring contrast‐to‐noise (CNR) and a signal‐to‐noise (SNR) index.Results:Reducing the contrast dose from 40 mL to 25 mL was found to significantly increase the CNR in several vessels of interest in the arterial tree. There was also a significant increase in the qualitative image quality score (P < 0.001).Conclusion:This study demonstrates that reducing the contrast dose at 3.0T can result in an increase in the CNR in the vessels of interest without significantly affecting the SNR. J. Magn. Reson. Imaging 2009;30:1059–1067. © 2009 Wiley‐Liss, Inc.
High‐b‐value diffusion‐weighted MR imaging of hepatocellular lesions: Estimation of grade of malignancy of hepatocellular carcinoma
Authors: Muhi Ali , Ichikawa Tomoaki , Motosugi Utaroh , Sano Katsuhiro , Matsuda Masanori , Kitamura Takatoshi , Nakazawa Tadao , Araki Tsutomu 
Published: October 2009

AbstractPurpose:To evaluate the effectiveness of diffusion‐weighted magnetic resonance imaging (DWI) in estimating the grade of malignancy of hepatocellular carcinoma.Materials and Methods:Dynamic contrast‐enhanced computed tomography (CE‐CT) and DWI (b value, 1000 s/mm2) were performed on 73 patients. Using DW images, the lesions were classified as “visible” or “invisible.” The apparent diffusion coefficient (ADC) of the lesions was measured. Furthermore, the lesions were classified as hypervascular or iso‐hypovascular using arterial phase CE‐CT images. The image findings for each lesion type were compared.Results:The 73 patients had 98 hepatocellular lesions, of which 12 were histologically diagnosed as dysplastic nodules; 39, well‐differentiated HCCs; 33, moderately differentiated HCCs; and 14, poorly differentiated HCCs. The mean ADC values of moderately poorly‐differentiated HCCs were significantly lower than well‐differentiated HCCs and dysplastic nodules (P < 0.01). On DW images, >90% of moderately (30/33) and poorly differentiated HCCs (13/14) were visible, while 51% of well‐differentiated HCCs (20/39) and all dysplastic nodules were invisible. Of 22 iso‐hypovascular lesions, 4 were visible on DW images and were poorly differentiated HCCs, whereas 18 were invisible and were dysplastic nodules (12/18) or well‐differentiated HCCs (6/18).Conclusion:A combination of hypovascularity and visibility on DW images can help distinguish poorly differentiated HCCs from low‐grade hepatocellular lesions (dysplastic nodules and well‐differentiated HCCs). J. Magn. Reson. Imaging 2009;30:1005–1011. © 2009 Wiley‐Liss, Inc.
Utility of phase contrast MR imaging for assessment of pulmonary flow and pressure estimation in patients with pulmonary hypertension: Comparison with right heart catheterization and echocardiography
Authors: Nogami Munenobu , Ohno Yoshiharu , Koyama Hisanobu , Kono Atsushi , Takenaka Daisuke , Kataoka Toshiya , Kawai Hiroya , Kawamitsu Hideaki , Onishi Yumiko , Matsumoto Keiko , Matsumoto Sumiaki , Sugimura Kazuro 
Published: October 2009

AbstractPurpose:To compare the utility of phase contrast MR imaging (PC‐MRI) for assessment of pulmonary flow and pressure estimation with that of right heart catheterization and echocardiography (cardiac US) in patients with pulmonary arterial hypertension (PAH).Materials and Methods:Twenty consecutive patients with suspected PAH underwent PC‐MRI, cardiac US, and right heart catheterization. In each patient, PC‐MRI was acquired by cine 2D‐PC method on a 1.5 Tesla scanner, and stroke volume (SV) and pulmonary arterial systolic pressure (PASP) were assessed by using the modified Bernoulli's equation. To evaluate the agreements of SV and PASP among the three methods, correlations and limits of agreement among the three methods were statistically assessed by using the Bland‐Altman's analyses.Results:The correlations and limits of agreement for SV and PASP between PC‐MRI and catheterization (r = 0.96, r2 = 0.94, 1.1 ± 6.9 mL and r = 0.94, r2 = 0.88, −3.2 ± 14.5 mmHg, respectively) were better than between cardiac US and catheterization (r = 0.01, r2 < 0.01, 8.9 ± 42.1 mL and r = 0.86, r2 = 0.72, −5.9 ± 27.7 mmHg, respectively).Conclusion:PC‐MRI is more compatible with right heart catheterization than cardiac US in pulmonary flow and pressure estimation. J. Magn. Reson. Imaging 2009;30:973–980. © 2009 Wiley‐Liss, Inc.
Imaging of the walls of saccular cerebral aneurysms with double inversion recovery black‐blood sequence
Authors: Park Ji Kang , Lee Chang Sub , Sim Ki Bum , Huh Ji Soon , Park Jung Cheol 
Published: October 2009

AbstractIn this study, we evaluated the wall of saccular cerebral aneurysms (SCAs) using two‐dimensional double inversion recovery black‐blood sequence (BBDI). We examined 14 patients with an unruptured SCA (USCA). The BBDI was peripheral‐pulse gated, and was acquired during the mid‐diastolic period. We evaluated whether the aneurysmal wall could be visualized with BBDI, and the wall thickness in the neck and dome portion of the aneurysm was measured in cases with acceptable imaging quality. BBDI demonstrated the USCA walls in ten patients. In four patients, the USCA walls were poorly delineated from the adjacent brain parenchyma or cerebrospinal fluid. The mean aneurysm size was 8.0 mm. The mean thickness of the aneurysmal wall in the neck portion was 0.60 ± 0.13 mm in 10 cases. The mean thickness at the dome portion was 0.46 ± 0.05 mm in five cases. In this study, BBDI revealed some portion of the USCA wall, despite the limited spatial and contrast resolution for delineation of the entire USCA wall. In our opinion, this technique may be used as an additional imaging tool for the evaluation of the aneurysmal wall. J. Magn. Reson. Imaging 2009;30:1179–1183. © 2009 Wiley‐Liss, Inc.
Diffusion‐weighted imaging of human carotid artery using 2D single‐shot interleaved multislice inner volume diffusion‐weighted echo planar imaging (2D ss‐IMIV‐DWEPI) at 3T: Diffusion measurement in atherosclerotic plaque
Authors: Kim Seong‐Eun , Jeong Eun‐Kee , Shi Xian‐Feng , Morrell Glen , Treiman Gerald S. , Parker Dennis L. 
Published: October 2009

AbstractPurpose:To determine if 2D single‐shot interleaved multislice inner volume diffusion‐weighted echo planar imaging (ss‐IMIV‐DWEPI) can be used to obtain quantitative diffusion measurements that can assist in the identification of plaque components in the cervical carotid artery.Materials and Methods:The 2D ss‐DWEPI sequence was combined with interleaved multislice inner volume region localization to obtain diffusion weighted images with 1 mm in‐plane resolution and 2 mm slice thickness. Eleven subjects, six of whom have carotid plaque, were studied with this technique. The apparent diffusion coefficient (ADC) images were calculated using DW images with b = 10 s/mm2 and b = 300 s/mm2.Results:The mean ADC measurement in normal vessel wall of the 11 subjects was 1.28 ± 0.09 × 10−3 mm2/s. Six of the 11 subjects had carotid plaque and ADC measurements in plaque ranged from 0.29 to 0.87 × 10−3 mm2/s. Of the 11 common carotid artery walls studied (33 images), at least partial visualization of the wall was obtained in all ADC images, more than 50% visualization in 82% (27/33 images), and full visualization in 18% (6/33 images).Conclusion:2D ss‐IMIV‐DWEPI can perform diffusion‐weighted carotid magnetic resonance imaging (MRI) in vivo with reasonably high spatial resolution (1 × 1 × 2 mm3). ADC values of the carotid wall and plaque are consistent with similar values obtained from ex vivo endarterectomy specimens. The spread in ADC values obtained from plaque indicate that this technique could form a basis for plaque component identification in conjunction with other MRI/MRA techniques. J. Magn. Reson. Imaging 2009;30:1068–1077. © 2009 Wiley‐Liss, Inc.
Effect of contrast media on single‐shot echo planar imaging: Implications for abdominal diffusion imaging
Authors: Gulani Vikas , Willatt Jonathan M. , Blaimer Martin , Hussain Hero K. , Duerk Jeffrey L. , Griswold Mark A. 
Published: October 2009

AbstractPurpose:The goal of this study was to determine the effect of contrast media on the signal behavior of single‐shot echo planar imaging (ssEPI) used for abdominal diffusion imaging.Materials and Methods:The signal of an ssEPI spin echo sequence in a water phantom with varying concentrations of gadolinium was modeled with Bloch equations and the predicted behavior validated on a phantom at 1.5T. Six volunteers were given gadolinium contrast and signal intensity (SI) time courses for regions of interest (ROIs) in the liver, pancreas, spleen, renal cortex, and medulla were analyzed. Student's t‐test was used to compare precontrast SI to 0, 1, 4, 5, 10, and 13 minutes following contrast.Results:The results show that following contrast ssEPI SI goes through a nadir, recovering differently for each organ. Maximal contrast‐related signal losses relative to precontrast signal are 20%, 20%, 53%, and 67% for the liver, pancreas, renal cortex, and medulla, respectively. The SIs remain statistically below the precontrast values for 5, 4, and 1 minute for the pancreas, liver, and spleen, and for all times measured for the renal cortex and medulla.Conclusion:Abdominal diffusion imaging should be performed prior to contrast due to adverse effects on the signal in ssEPI. J. Magn. Reson. Imaging 2009;30:1203–1208. © 2009 Wiley‐Liss, Inc.
Relationship of temporal resolution to diagnostic performance for dynamic contrast enhanced MRI of the breast
Authors: El Khouli Riham H. , Macura Katarzyna J. , Barker Peter B. , Habba Mohamed R. , Jacobs Michael A. , Bluemke David A. 
Published: October 2009

AbstractPurpose:To investigate the relationship between temporal resolution of dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) and classification of breast lesions as benign versus malignant.Materials and Methods:Patients underwent T1‐weighted DCE MRI with 15 s/acquisition temporal resolution using 1.5 Tesla (n = 48) and 3.0T (n = 33) MRI scanners. Seventy‐nine patients had pathologically proven diagnosis and 2 had 2 years follow‐up showing no change in lesion size. The temporal resolution of DCE MRI was systematically reduced as a postprocessing step from 15 to 30, 45, and 60 s/acquisition by eliminating intermediate time points. Average wash‐in and wash‐out slopes, wash‐out percentage changes, and kinetic curve shape (persistently enhancing, plateau, or wash‐out) were compared for each temporal resolution. Logistic regression and receiver operating characteristic (ROC) curve analysis were used to compare kinetic parameters and diagnostic accuracy.Results:Sixty patients (74%) had malignant lesions and 21 patients (26%) had benign lesions. All temporal‐resolution parameters significantly predicted benign versus malignant diagnosis (P < 0.05). However, 45 s/acquisition and higher temporal‐resolution datasets showed higher accuracy than the 60 s/acquisition dataset by ROC curve analysis (0.72 versus 0.69 for average wash‐in slope; 0.85 versus 0.82, for average wash‐out slope; and 0.88 versus 0.80 for kinetic curve shape assessment, for 45 s/acquisition versus 60 s/acquisition temporal‐resolution datasets, respectively (P = 0.027).Conclusion:DCE MRI data with at least 45‐s temporal resolution maximized the agreement between the kinetic parameters and correct classification of benign versus malignant diagnosis. J. Magn. Reson. Imaging 2009;30:999–1004. © 2009 Wiley‐Liss, Inc.
Minimization of Nyquist ghosting for echo‐planar imaging at ultra‐high fields based on a “negative readout gradient” strategy
Authors: van der Zwaag Wietske , Marques José P. , Lei Hongxia , Just Nathalie , Kober Tobias , Gruetter Rolf 
Published: October 2009

AbstractPurpose:To improve the traditional Nyquist ghost correction approach in echo planar imaging (EPI) at high fields, via schemes based on the reversal of the EPI readout gradient polarity for every other volume throughout a functional magnetic resonance imaging (fMRI) acquisition train.Materials and Methods:An EPI sequence in which the readout gradient was inverted every other volume was implemented on two ultrahigh‐field systems. Phantom images and fMRI data were acquired to evaluate ghost intensities and the presence of false‐positive blood oxygenation level‐dependent (BOLD) signal with and without ghost correction. Three different algorithms for ghost correction of alternating readout EPI were compared.Results:Irrespective of the chosen processing approach, ghosting was significantly reduced (up to 70% lower intensity) in both rat brain images acquired on a 9.4T animal scanner and human brain images acquired at 7T, resulting in a reduction of sources of false‐positive activation in fMRI data.Conclusion:It is concluded that at high B0 fields, substantial gains in Nyquist ghost correction of echo planar time series are possible by alternating the readout gradient every other volume. J. Magn. Reson. Imaging 2009;30:1171–1178. © 2009 Wiley‐Liss, Inc.
Impact of papillary and trabecular muscles on quantitative analyses of cardiac function in hypertrophic cardiomyopathy
Authors: Han Yuchi , Osborn Eric A. , Maron Martin S. , Manning Warren J. , Yeon Susan B. 
Published: October 2009

AbstractPurpose:To examine the impact of cardiovascular magnetic resonance (CMR) partitioning methods on volumetric analysis in hypertrophic cardiomyopathy (HCM) patients. The standard CMR method for partitioning ventricular myocardium from ventricular cavity includes the myocardial papillary and trabecular muscles in the cavity volume. This approach may misrepresent ventricular mass and volume in patients with HCM due to large papillary muscles and extensive trabeculations.Materials and Methods:Ventricular volume and mass analyses were performed in 30 patients with HCM using the standard method and a detailed method that excluded papillary and trabecular muscles from the left ventricular (LV) volume while including them in LV mass. We also analyzed the degree of mitral regurgitation and compared the results with Doppler echocardiography in a subgroup of 12 patients. Interobserver variability was assessed.Results:The detailed method yielded 17% higher indexed LV mass, 20% lower indexed LV diastolic volume, 13% higher LV ejection fraction (EF) (all P < 0.0001). The resultant mitral regurgitant volumes using the detailed method had less discrepancy with Doppler echocardiography results compared with the results from the standard methods. Interobserver variability was similar by both methods.Conclusion:For patients with HCM, a detailed analysis in which the ventricular papillary and trabecular muscles are excluded from LV volume is preferred. J. Magn. Reson. Imaging 2009;30:1197–1202. © 2009 Wiley‐Liss, Inc.
7 Tesla MR imaging of the human eye in vivo
Authors: Richdale Kathryn , Wassenaar Peter , Teal Bluestein Katharine , Abduljalil Amir , Christoforidis John A. , Lanz Titus , Knopp Michael V. , Schmalbrock Petra 
Published: October 2009

AbstractPurpose:To develop a protocol which optimizes contrast, resolution and scan time for three‐dimensional (3D) imaging of the human eye in vivo using a 7 Tesla (T) scanner and custom radio frequency (RF) coil.Materials and Methods:Initial testing was conducted to reduce motion and susceptibility artifacts. Three‐dimensional FFE and IR‐TFE images were obtained with variable flip angles and TI times. T1 measurements were made and numerical simulations were performed to determine the ideal contrast of certain ocular structures. Studies were performed to optimize resolution and signal‐to‐noise ratio (SNR) with scan times from 20 s to 5 min.Results:Motion and susceptibility artifacts were reduced through careful subject preparation. T1 values of the ocular structures are in line with previous work at 1.5T. A voxel size of 0.15 × 0.25 × 1.0 mm3 was obtained with a scan time of approximately 35 s for both 3D FFE and IR‐TFE sequences. Multiple images were registered in 3D to produce final SNRs over 40.Conclusion:Optimization of pulse sequences and avoidance of susceptibility and motion artifacts led to high quality images with spatial resolution and SNR exceeding prior work. Ocular imaging at 7T with a dedicated coil improves the ability to make measurements of the fine structures of the eye. J. Magn. Reson. Imaging 2009;30:924–932. © 2009 Wiley‐Liss, Inc.