bluuebunny/crossref_metadata_2025_split huggingface dataset:
Noncontrast SSFP pulmonary vein magnetic resonance angiography: Impact of off‐resonance and flow
Authors: Hu Peng , Stoeck Christian T. , Smink Jouke , Peters Dana C. , Ngo Long , Goddu Beth , Kissinger Kraig V. , Goepfert Lois A. , Chan Jonathan , Hauser Thomas H. , Rofsky Neil M. , Manning Warren J. , Nezafat Reza 
Published: October 2010

AbstractPurposeTo investigate pulmonary vein (PV) off‐resonance and blood flow as causes of signal void artifacts in noncontrast steady‐state‐free‐precession (SSFP) PV magnetic resonance angiography (MRA).Materials and MethodsPV blood off‐resonance was measured on 11 healthy adult subjects and 10 atrial fibrillation (AF) patients. Noncontrast PV MRA was performed using a 3D slab‐selective SSFP sequence at 1.5T on seven healthy subjects with signal profile shifts of 0–125 Hz. The time‐resolved blood flow velocity of the PVs was measured on five healthy subjects. The impact of flow was studied on six healthy subjects, on whom SSFP PV MRA was acquired twice with the electrocardiogram (ECG) trigger delay corresponding to low and high flow, respectively.ResultsThe PV off‐resonances were 97 ± 27 Hz, 65 ± 20 Hz, 74 ± 25 Hz, and 52 ± 17 Hz for right inferior, left inferior, right superior, and left superior PVs, respectively, on healthy subjects, and 74 ± 20 Hz, 38 ± 9 Hz, 51 ± 20 Hz, and 28 ± 11 Hz on AF patients (P<0.01 for all). The off‐resonance caused severe signal voids in the PVs. Signal acquired during mid‐diastole with high PV flow caused additional signal voids in the left atrium, which was reduced by setting the ECG trigger delay to late‐diastole.ConclusionPV off‐resonance and flow causes signal void artifacts in noncontrast 3D slab‐selective SSFP PV MRA. J. Magn. Reson. Imaging 2010;32:1255–1261. © 2010 Wiley‐Liss, Inc.
Reconstruction of 3D dynamic contrast‐enhanced magnetic resonance imaging using nonlocal means
Authors: Adluru Ganesh , Tasdizen Tolga , Schabel Matthias C. , DiBella Edward V.R. 
Published: October 2010

AbstractPurposeTo develop and test a nonlocal means‐based reconstruction algorithm for undersampled 3D dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) of tumors.Materials and MethodsWe propose a reconstruction technique that is based on the recently proposed nonlocal means (NLM) filter which can relax trade‐offs in spatial and temporal resolutions in dynamic imaging. Unlike the original application of NLM for image denoising, the MR reconstruction framework here can offer high‐quality images from undersampled k‐space data. The method is based on enforcing similarity constraints in terms of neighborhoods of pixels rather than individual pixels. The method was applied on undersampled 3D DCE imaging of breast and brain tumor datasets and the results were compared to sliding window reconstructions and to a compressed sensing method using total variation constraints on the images.ResultsUndersampling factors of up to five were obtained with the proposed approach while preserving the spatial and temporal characteristics. The NLM reconstruction method offered improved performance over the sliding window and the total variation constrained reconstruction techniques.ConclusionThe reconstruction framework here can give high‐quality images from undersampled DCE MRI data and has the potential to improve the quality of DCE tumor imaging. J. Magn. Reson. Imaging 2010;32:1217–1227. © 2010 Wiley‐Liss, Inc.
Improved aortic pulse wave velocity assessment from multislice two‐directional in‐plane velocity‐encoded magnetic resonance imaging
Authors: Westenberg Jos J.M. , de Roos Albert , Grotenhuis Heynric B. , Steendijk Paul , Hendriksen Dennis , van den Boogaard Pieter J. , van der Geest Rob J. , Bax Jeroen J. , Jukema J. Wouter , Reiber Johan H.C. 
Published: October 2010

AbstractPurposeTo evaluate the accuracy and reproducibility of aortic pulse wave velocity (PWV) assessment by in‐plane velocity‐encoded magnetic resonance imaging (MRI).Materials and MethodsIn 14 patients selected for cardiac catheterization on suspicion of coronary artery disease and 15 healthy volunteers, PWV was assessed with multislice two‐directional in‐plane velocity‐encoded MRI (PWVi.p.) and compared with conventionally assessed PWV from multisite one‐directional through‐plane velocity‐encoded MRI (PWVt.p.). In patients, PWV was also obtained from intraarterially acquired pressure–time curves (PWVpressure), which is considered the gold standard reference method. In volunteers, PWVi.p. and PWVt.p. were obtained in duplicate in the same examination to test reproducibility.ResultsIn patients, PWVi.p. showed stronger correlation and similar variation with PWVpressure than PWVt.p. (Pearson correlation r = 0.75 vs. r = 0.58, and coefficient of variation [COV] = 10% vs. COV = 12%, respectively). In volunteers, repeated PWVi.p. assessment showed stronger correlation and less variation than repeated PWVt.p. (proximal aorta: r = 0.97 and COV = 10% vs. r = 0.69 and COV = 17%; distal aorta: r = 0.94 and COV = 12% vs. r = 0.90 and COV = 16%; total aorta: r = 0.97 and COV = 7% vs. r = 0.90 and COV = 13%).ConclusionPWVi.p. is an improvement over conventional PWVt.p. by showing higher agreement as compared to the gold standard (PWVpressure) and higher reproducibility for repeated MRI assessment. J. Magn. Reson. Imaging 2010;32:1086–1094. © 2010 Wiley‐Liss, Inc.
Diagnosis of colorectal hepatic metastases: Contrast‐enhanced ultrasonography versus contrast‐enhanced computed tomography versus superparamagnetic iron oxide‐enhanced magnetic resonance imaging with diffusion‐weighted imaging
Authors: Muhi Ali , Ichikawa Tomoaki , Motosugi Utaroh , Sou Hironobu , Nakajima Hiroto , Sano Katsuhiro , Kitamura Takatoshi , Faima Zareen , Fukushima Kimiyo , Araki Tsutomu , Iino Hiroshi , Mori Yoshiyuki , Fujii Hideki 
Published: October 2010

AbstractPurposeTo compare the diagnostic accuracy of contrast‐enhanced ultrasonography (CE‐US), contrast‐enhanced CT (CE‐CT), and superparamagnetic iron oxide‐enhanced MRI (SPIO‐MRI) with diffusion‐weighted imaging (DWI) in the evaluation of colorectal hepatic metastases.Materials and MethodsThirty‐six patients with colorectal cancers were prospectively enrolled and retrospectively evaluated. Of the 86 metastases identified, 16 were confirmed histologically and the remaining 70 were confirmed by follow‐up imaging. CE‐CT and SPIO‐MRI + DWI were independently evaluated by two readers, whereas CE‐US was evaluated by consensus reading of two different readers. Area under receiver operating characteristic curve (Az), sensitivities, and positive predictive values (PPVs) were calculated and compared.ResultsFor both readers, SPIO‐MRI+DWI had significantly greater Az (0.879 and 0.904) and sensitivity (78% and 87%) for all lesions compared with CE‐CT (0.779 and 0.793; 59% and 59%) and CE‐US (0.811; 69%), and significantly greater Az (0.783 and 0.837) and sensitivity (56% and 73%) for lesions ≤1 cm compared with CE‐CT (0.562 and 0.601; 20% and 22%) and CE‐US (0.66; 37%). For lesions >1 cm, there was no significant difference in Az, sensitivity and PPV between all the image sets.ConclusionSPIO‐MRI with DWI was the most reliable modality for evaluation of liver metastases particularly for lesions ≤1 cm. J. Magn. Reson. Imaging 2010;32:1132–1140. © 2010 Wiley‐Liss, Inc.
Association between serial dynamic contrast‐enhanced MRI and dynamic 18F‐FDG PET measures in patients undergoing neoadjuvant chemotherapy for locally advanced breast cancer
Authors: Partridge Savannah C. , Vanantwerp Risa K. , Doot Robert K. , Chai Xiaoyu , Kurland Brenda F. , Eby Peter R. , Specht Jennifer M. , Dunnwald Lisa K. , Schubert Erin K. , Lehman Constance D. , Mankoff David A. 
Published: October 2010

AbstractPurposeTo investigate the relationship between changes in vascularity and metabolic activity measured by dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI) and dynamic 18F‐FDG‐positron emission tomography (PET) in breast tumors undergoing neoadjuvant chemotherapy.Materials and MethodsPET and MRI examinations were performed in 14 patients with locally advanced breast cancer (LABC) before and after chemotherapy. Dynamic 18F‐FDG PET measures included 18F‐FDG transport rate constant from blood to tissue (K1) and metabolism flux constant (Ki). DCE‐MRI measures included initial peak enhancement (PE), signal enhancement ratio (SER), and tumor volume. Spearman rank‐order correlations were assessed between changes in PET and MRI parameters, and measures were compared between patients with and without pathologic complete response (pCR) by Mann–Whitney U‐test.ResultsChanges in glucose delivery (PET K1) were closely correlated with changes in tumor vascularity as reflected by DCE‐MRI SER (r = 0.83, P < 0.001). Metabolic changes in PET Ki showed moderate correlations with vascularity changes as reflected by SER (r = 0.71) and PE (r = 0.76), and correlated closely with MRI tumor volume (r = 0.79, P < 0.001). Decreases in K1, Ki, SER, and PE were greater for patients with pCR compared to those with residual disease (P < 0.05).ConclusionDynamic 18F‐FDG PET and DCE‐MRI tumor measures of tumor metabolism, vascularity, and volume were well correlated for assessing LABC response to neoadjuvant chemotherapy and significantly discriminated pathologic complete responders. Further work is necessary to assess the value of combined PET and MRI for evaluating tumor pharmacodynamics in response to novel therapy. J. Magn. Reson. Imaging 2010;32:1124–1131. © 2010 Wiley‐Liss, Inc.
Chemical shift imaging in the head and neck at 3T: Initial results
Authors: Yeung David K.W. , Fong Kwan‐Ying , Chan Queenie C.C. , King Ann D. 
Published: October 2010

AbstractPurposeTo determine the optimal method to correct air and tissue susceptibility differences in the head and neck to allow proton (1H) chemical shift imaging (CSI) to be performed at 3T.Materials and MethodsShimming protocols (iterative, first‐order, and second‐order) and perfluorocarbon (PFC) pads were evaluated using water peak linewidth measurements obtained from single‐voxel magnetic resonance spectroscopy (MRS) on a head and neck phantom. After optimization of the technique, CSI was then tested on 14 patients with head and neck tumors.ResultsSecond‐order shimming (water peak linewidth, 4.6 Hz) performed significantly (P < 0.001) better than first‐order (16.5 Hz) and iterative shimming (18 Hz) and the water peak linewidth was significantly reduced using PFC pads (P < 0.001). Using second‐order shimming and PFC pads, CSI was successful in 10 patients with nodal metastases (n = 8) and benign tumors (n = 2) and unsuccessful in four patients with primary tumors along the aerodigestive tract.ConclusionProton CSI can be successfully performed in the head and neck using second‐order shimming and PFC pads to correct air and tissue susceptibility differences. CSI was more successfully performed on nodal metastases, while CSI for primary tumors along the aerodigestive tract remains a challenge. J. Magn. Reson. Imaging 2010;32:1248–1254. © 2010 Wiley‐Liss, Inc.
Diffusion tensor imaging of liver fibrosis in an experimental model
Authors: Cheung Jerry S. , Fan Shu Juan , Gao Darwin S. , Chow April M. , Man Kwan , Wu Ed X. 
Published: October 2010

AbstractPurposeTo characterize changes in diffusion properties of liver using diffusion tensor imaging (DTI) in an experimental model of liver fibrosis.Materials and MethodsLiver fibrosis was induced in Sprague–Dawley rats (n = 12) by repetitive dosing of carbon tetrachloride (CCl4). The animals were examined with a respiratory‐gated single‐shot spin‐echo echo‐planar DTI protocol at 7 T before, 2 weeks after, and 4 weeks after CCl4 insult. Apparent diffusion coefficient (ADC), directional diffusivities (ADC// and ADC⟂), and fractional anisotropy (FA) were measured. Liver histology was performed with hematoxylin‐eosin staining and Masson's trichrome staining.ResultsSignificant decrease (P < 0.01) in ADC was found at 2 weeks (0.86 ± 0.09 × 10−3 mm2/s) and 4 weeks (0.74 ± 0.09 × 10−3 mm2/s) following CCl4 insult, as compared with that before insult (0.97 ± 0.08 × 10−3 mm2/s). Meanwhile, FA at 2 weeks (0.18 ± 0.03) after CCl4 insult was significantly lower (P < 0.01) than that before insult (0.26 ± 0.05), and subsequently normalized at 4 weeks (0.26 ± 0.07) after the insult. Histology showed collagen deposition, presence of intracellular fat vacuoles, and cell necrosis/apoptosis in livers with CCl4 insult.ConclusionDTI detected the progressive changes in water diffusivities and diffusion anisotropy of liver tissue in this liver fibrosis model. ADC and FA are potentially valuable in detecting liver fibrosis at early stages and monitoring its progression. Future human studies are warranted to further verify the applicability of DTI in characterizing liver fibrosis and to determine its role in clinical settings. J. Magn. Reson. Imaging 2010;32:1141–1148. © 2010 Wiley‐Liss, Inc.
Comparison of magnetic resonance imaging with transthoracic echocardiography in the diagnosis of ventricular septal defect‐associated coronary cusp prolapse
Authors: Yoshimura Norihiko , Hori Yoshiro , Horii Yousuke , Suzuki Hiroshi , Hasegawa Satoshi , Takahashi Masashi , Watanabe Hiroshi 
Published: October 2010

AbstractPurposeTo compare magnetic resonance imaging (MRI) with transthoracic echocardiography (TTE) in the diagnosis of coronary cusp prolapse (CCP) as a complication of ventricular septal defect (VSD).Materials and MethodsTwenty‐three patients (10 males, 13 females, mean age 9 years) with clinically suspected CCP were included in a retrospective study. Long and short axis cine images and electrocardiogram (ECG)‐gated axial T1‐weighted image MRI images were evaluated for deformity and protrusion of right and noncoronary cusps. We compared MRI and TTE results. We compared the agreement between MRI and TTE in outlet VSD and membranous VSD.ResultsOn MRI, 19 patients had right coronary cusp prolapse (RCCP), three had noncoronary cusp prolapse (NCCP), and one patient had RCCP and NCCP on MRI. Twenty‐two patients had RCCP on TTE and none had NCCP. Seventeen patients had outlet defects and six patients had a membranous defect at operation. All patients with an outlet VSD had RCCP on both MRI and TTE. The agreement between MRI and TTE in outlet VSD was better than in membranous VSD.ConclusionMRI results corresponded with TTE results in patients with outlet VSDs, but discordant results were observed in patients with membranous VSDs. J. Magn. Reson. Imaging 2010;32:1099–1103. © 2010 Wiley‐Liss, Inc.
Effects of formalin fixation on magnetic resonance indices in multiple sclerosis cortical gray matter
Authors: Schmierer Klaus , Thavarajah Janet R. , An Shu F. , Brandner Sebastian , Miller David H. , Tozer Daniel J. 
Published: October 2010

AbstractPurposeTo investigate changes in magnetic resonance imaging (MRI) indices following formalin fixation of postmortem multiple sclerosis (MS) cortical gray matter (CGM). Postmortem MS brain is being used to establish pathological correlates of changes detected using MRI, with recent emphasis on CGM. Fixation induces tissue alterations that may confound inference of in vivo observations from MRI/histology correlation studies.Materials and MethodsT2‐weighted scans were obtained alongside quantitative T1, magnetization transfer ratio (MTR), and macromolecular proton fraction (fB) measurements before and after formalin fixation of 15 postmortem brain samples. Type and size of CGM lesions (CGML) was identified on sections immunostained for myelin basic protein.ResultsMRI indices obtained in unfixed MS CGM were similar to values obtained in subjects with MS in vivo. Fixation led to reduction in T1 (617 msec [standard deviation = 114] vs. 1156 msec [216]) and MTR (24.1 [3.3] percent units [pu] vs. 29.1 [2.5] pu) and increase in fB (5.4 [0.7] pu vs. 3.2 [2.3] pu) (all P < 0.01). The proportion of CGM affected by demyelination did not alter the MRI data.ConclusionMRI indices in the CGM are significantly altered following tissue fixation. J. Magn. Reson. Imaging 2010;32:1054–1060. © 2010 Wiley‐Liss, Inc.
Breaking rules for the right reasons? An investigation of pro‐social rule breaking
Authors: Dahling Jason J. , Chau Samantha L. , Mayer David M. , Gregory Jane B. 
Published: October 2010

SummaryPro‐social rule breaking (PSRB) is a form of constructive deviance characterized by volitional rule breaking in the interest of the organization or its stakeholders. Over the course of three studies, we developed a generalizable measure of PSRB and placed it in a nomological network with personality, workplace perceptions, counterproductive behaviors, and task and contextual performance ratings made by supervisors and coworkers. Results indicate that PSRB is negatively related to task performance ratings across both sources despite its pro‐social motivation intended to help the organization. Potential directions for future research concerning reactions to constructive deviance are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Can testate amoeba‐based palaeohydrology be extended to fens?
Authors: Payne Richard J. 
Published: October 2010

AbstractNumerous palaeoecological studies have used testate amoeba analysis to reconstruct Holocene hydrological change in peatlands, and thereby past climatic change. Current studies have been almost exclusively restricted to ombrotrophic bogs and the period since the fen–bog transition. Although the critical link between peatland surface wetness and climate is less direct in minerotrophic peatlands, such records may still be of value where there are few others, particularly if multiple records can be derived and inter‐compared. Expanding the temporal and spatial scope of testate amoeba‐based palaeohydrology to minerotrophic peatlands requires studies to establish the primacy of hydrology and the efficacy of transfer functions across a range of sites. This study analyses testate amoeba data from wetlands spanning the trophic gradient in the eastern Mediterranean region. Results demonstrate that different types of wetlands have distinctly different amoeba communities, but hydrology remains the most important environmental control (despite water table depth being measured at different times for different sites). Interestingly, Zn and Fe emerge as significant environmental variables in a subset of sites with geochemical data. Testate amoeba–hydrology transfer functions perform well in cross‐validation but frequently perform poorly when applied to other sites, particularly with sites of a different nutrient status. It may be valid to use testate amoebae to reconstruct hydrological change from minerotrophic peatlands with an applicable transfer function; however, it may not be appropriate to use testate amoebae to reconstruct hydrological change through periods of ecosystem evolution, particularly the fen–bog transition. In practice, the preservation of amoeba shells is likely to be a key problem for palaeoecological reconstruction from fens. Copyright © 2010 John Wiley & Sons, Ltd.
Genetic alterations of K‐ras may reflect prognosis in stage III colon cancer patients below 60 years of age
Authors: Onozato Wataru , Yamashita Keishi , Yamashita Kazuya , Kuba Tatsuru , Katoh Hiroshi , Nakamura Takatoshi , Sato Takeo , Ihara Atsushi , Okayasu Isao , Watanabe Masahiko 
Published: October 2010

AbstractPurposeGenetic alterations that are closely associated with patient prognosis can be landmarks of definitive therapeutic targets as well as useful biomarkers in human cancer clinics.MethodsThree hundred seventy‐eight colorectal cancer (CRC) patients were examined for K‐ras mutations by single‐strand conformation polymorphism (SSCP), with a subsequent 144 young colon cancer (YCC) patients added to validate its prognostic significance.ResultsK‐ras mutations were identified in 161 (43%) of the 378 CRC patients and were significantly associated with tumor location (colon vs. rectum; 80/218 = 37% vs. 81/160 = 51%; P = 0.0068) and age (≥60 vs. <60; 103/220 = 47% vs. 58/158 = 37%; P = 0.049). The incidence of K‐ras mutations was 30% in YCC patients as compared to 55% in elderly rectal cancer patients (P = 0.0004). K‐ras mutations significantly correlated with a worse prognosis (P = 0.0014) only in 73 curatively resected YCC with stages I–III, but not in other CRCs, which was further validated in the independent set of the corresponding 144 YCC patients (P = 0.024). Both univariate and multivariate analyses identified K‐ras mutations as an independent prognostic factor (HR = 5.5, P = 0.029; HR = 3.6, P = 0.011) in both learning and validation sets of the curatively resected YCC with stages I–III, respectively, and the prognostic relevance was marked in stage III YCC patients (P = 0.002), but not in stages I, II, and IV.ConclusionIn curative YCC, K‐ras mutations could have excellent prognostic value. Hence, the K‐ras mutation status could be a good indicator to predict the clinical outcome in curatively resected stage III YCC patients, and K‐ras pathway inhibition may be a relevant therapeutic target in CRC, excluding YCC patients with no K‐ras mutation. J. Surg. Oncol. 2011;103:25–33. © 2010 Wiley‐Liss, Inc.
Conformal radiofrequency ablation of hepatocellular carcinoma with a multi‐pin bipolar system
Authors: Peng Zhen‐Wei , Liang Hui‐Hong , Chen Min‐Shan , Zhang Yao‐Jun , Zhang Ya‐Qi , Lau Wan Y. 
Published: October 2010

AbstractBackgroundTo retrospectively evaluate the effectiveness and safety of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) with a multi‐pin bipolar system.MethodsBetween August 2005 and December 2006, 18 patients with 30 HCCs (3.40 ± 1.24 cm, range 1.30–6.0 cm; median number of treated lesions is two per patient, range, 1–3) underwent percutaneous RFA with a multi‐pin bipolar system under ultrasound guidance. The primary end‐point were treatment efficacy, major and minor complications, and the secondary end‐point were overall survival and tumor‐free survival.ResultsComplete ablation with conformed shape to the index tumor was achieved in 16 of 18 patients, and 28 of the 30 tumors were completely ablated. On follow‐up, local and distant intrahepatic tumor progression rates were 12.5% (2 of 16 patients) and 62.5% (10 of 16 patients). There was no patient who developed extrahepatic metastasis. There were no major complications. The 1‐, 2‐year overall survival rates for all patients were 83.3%, 55.6%, respectively, and the corresponding tumor‐free survivals were 50.0%, 22.2%, respectively.ConclusionRFA with a multi‐pin bipolar system was effective and safe for HCC. A large ablation volume could be achieved which conformed to the shape of the index tumor. J. Surg. Oncol. 2011;103:69–74. © 2010 Wiley‐Liss, Inc.