bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of spontaneous healing of chronic posterior cruciate ligament injury: Analysis of instability and magnetic resonance imaging
Authors: Jung Young‐Bok , Jung Ho‐Joong , Yang Jae Jun , Yang Dong‐Lyul , Lee Yong Seuk , Song In‐Sup , Lee Han Jun 
Published: May 2008

AbstractPurposeTo explore the healing process of the injured posterior cruciate ligament (PCL) by evaluating instability measurements and magnetic resonance imaging (MRI) findings.Materials and MethodsA retrospective cross‐sectional study of 46 cases of complete PCL tear who obtained MRI more than two months after injury.ResultsA total of 13 cases (28%) showed nearly normal PCL contour, 20 cases (44%) showed continuity but deformed PCL contour, and 13 cases (28%) showed discontinuity. The duration from injury to MRI was not directly correlated with continuity. However, the group that obtained MRI more than six months after injury showed more continuity than the group that obtained MRI within six months of the injury (P < 0.01). The group with nearly normal continuity showed better stability results in the KT‐1000 arthrometer and stress radiographs than the group with discontinuity (P < 0.05). The presence of other combined ligament injuries had a negative effect on regaining PCL continuity (P <0.05).ConclusionMore than two‐thirds (72%) of chronic PCL injury cases showed ligamentous continuity on MRI, especially when the injury had occurred more than six months before. Stability may improve as continuity is regained. The presence of other combined ligament injuries appears to prohibit spontaneous PCL healing. J. Magn. Reson. Imaging 2008;27:1336–1340. © 2008 Wiley‐Liss, Inc.
Apparent diffusion coefficient in pancreatic cancer: Characterization and histopathological correlations
Authors: Muraoka Noriaki , Uematsu Hidemasa , Kimura Hirohiko , Imamura Yoshiaki , Fujiwara Yasuhiro , Murakami Makoto , Yamaguchi Akio , Itoh Harumi 
Published: May 2008

AbstractPurposeTo clarify the components primarily responsible for diffusion abnormalities in pancreatic cancerous tissue.Materials and MethodsSubjects comprised 10 patients with surgically confirmed pancreatic cancer. Diffusion‐weighted (DW) echo‐planar imaging (b value = 0, 500 s/mm2) was employed to calculate the apparent diffusion coefficient (ADC). ADC values of cancer and noncancerous tissue were calculated. Furthermore, ADC values of the cancer were compared with histopathological results.ResultsThe mean (±standard deviation) ADC value was significantly lower for tumor (1.27 ± 0.52 × 10−3 mm2/s) than for noncancerous tissue (1.90 ± 0.41 × 10−3 mm2/s, P < 0.05). Histopathological examination showed similar proportions of fibrotic area, cellular component, necrosis, and mucin in each case. Regarding the density of fibrosis in cancer, three cases were classified in the loose fibrosis group and the remaining seven cases were classified in the dense fibrosis group. The mean ADC value was significantly higher in the loose fibrosis group (1.88 ± 0.39 × 10−3 mm2/s) than in the dense fibrosis group (1.01 ± 0.29 × 10−3 mm2/s, P < 0.05). In quantitative analysis, ADC correlated well with the proportion of collagenous fibers (r = −0.87, P < 0.05).ConclusionCollagenous fibers may be responsible for diffusion abnormalities in pancreatic cancer. J. Magn. Reson. Imaging 2008;27:1302–1308. © 2008 Wiley‐Liss, Inc.
Comparison of three physiologically‐based pharmacokinetic models for the prediction of contrast agent distribution measured by dynamic MR imaging
Authors: Barboriak Daniel P. , MacFall James R. , Viglianti Benjamin L. , Dewhirst DVM Mark W. 
Published: May 2008

AbstractPurposeTo compare the performance of three physiologically‐based pharmacokinetic (PBPK) models for predicting gadolinium contrast agent concentration‐time curves (Gd‐CTCs) obtained in superior sagittal sinus (SSS), cerebral cortex, and psoas muscle.Materials and MethodsThree published whole‐body PBPK models were modified to predict Gd‐CTCs in normal‐appearing tissue. The models differed in the number of organs modeled and total number of compartments, and were designated as the “well‐mixed,” “delay,” and “dispersion” models. The suitability of the three models to predict Gd‐CTC was studied using data from dynamic contrast‐enhanced MR perfusion imaging obtained at 1.5T from 10 patients with glioblastoma multiforme and at 3.0T from five patients with liver metastases.ResultsThe dispersion model produced better fits than the delay model in the SSS (P < 0.0001) and cerebral cortex (P < 0.0001), and better fits than the well‐mixed model in psoas muscle (P < 0.005). No model produced better fits than the dispersion model at any of the three locations.ConclusionIn this evaluation, the dispersion model was most robust for prediction of Gd‐CTCs derived from dynamic contrast‐enhanced (DCE)‐MRI. This represents a preliminary step in the development of a PBPK model useful for predicting Gd‐CTCs at a time resolution appropriate for dynamic MRI applications. J. Magn. Reson. Imaging 2008;27:1388–1398. © 2008 Wiley‐Liss, Inc.
Dynamic MRI, dynamic multidetector‐row computed tomography (MDCT), and coregistered 2‐[fluorine‐18]‐fluoro‐2‐deoxy‐D‐glucose–positron emission tomography (FDG‐PET)/CT: Comparative study of capability for management of pulmonary nodules
Authors: Ohno Yoshiharu , Koyama Hisanobu , Takenaka Daisuke , Nogami Munenobu , Maniwa Yoshimasa , Nishimura Yoshihiro , Ohbayashi Chiho , Sugimura Kazuro 
Published: May 2008

AbstractPurposeTo compare the nodule management capabilities of dynamic MRI, dynamic multidetector‐row computed tomography (MDCT) and coregistered positron emission tomography (PET)/CT.Materials and MethodsDynamic MRI, dynamic MDCT, PET, microbacterial, and pathological examinations were administered to 175 consecutive patients with 202 nodules (<30 mm in diameter). The final diagnoses resulted in the classification of 202 nodules into two groups: requiring further intervention and treatment (N = 163) and no further evaluation (N = 39) groups. Maximum relative enhancement and slope of enhancement ratio were calculated as dynamic MR indices. Maximum enhancement, net enhancement, slope of enhancement, and absolute loss of enhancement were calculated as dynamic CT indices. maximum value of standard uptake value (SUVmax) was measured on coregistered PET/CT. Receiver operating characteristics (ROC) analyses were performed to determine feasible threshold values for nodule management, and results were tested using McNemar's test.ResultsWhen feasibility threshold values were adopted for nodule management, the specificity (82.1%) and accuracy (93.6%) of the slope of the enhancement ratio were significantly higher than those of dynamic CT indices (P < 0.05) and SUVmax (P < 0.05).ConclusionDynamic MRI can play a more specific and/or accurate role for nodule management as compared with dynamic MDCT and coregistered PET/CT. J. Magn. Reson. Imaging 2008;27:1284–1295. © 2008 Wiley‐Liss, Inc.
MR factor analysis: Improved technology for the assessment of 2D dynamic structures of benign and malignant salivary gland tumors
Authors: Eida Sato , Ohki Masafumi , Sumi Misa , Yamada Toshiro , Nakamura Takashi 
Published: May 2008

AbstractPurposeTo establish an MR factor analysis technique for two‐dimensional (2D) MR dynamic structures of benign and malignant salivary gland tumors.Materials and MethodsDynamic contrast‐enhanced MRI using a surface coil was performed on 36 patients with benign (N = 24) or malignant (N = 12) salivary gland tumors. Signal intensity kinetics in each pixel of the tumors after contrast medium injections were semiautomatically categorized into four patterns (slow uptake, rapid uptake with high washout, rapid uptake with low washout, and flat). The 2D distributions of the kinetic patterns in the tumors were compared with the histological features of the corresponding parts of the excised tumors and with overall kinetics obtained by a conventional analysis.ResultsThe MR factor analysis technique allowed the pixel‐to‐pixel evaluation of the contrast enhancement kinetics of the salivary gland tumors. The 2D distributions of the time‐intensity curve (TIC) patterns correlated well with the histological features of the salivary gland tumors and allowed more detailed dynamic structures of the tumors compared with the results obtained by the conventional dynamic study analysis.ConclusionThe proposed MR factor analysis would be clinically feasible to diagnose salivary gland tumors and tumor‐like lesions. J. Magn. Reson. Imaging 2008;27:1256–1262. © 2008 Wiley‐Liss, Inc.
Evaluation of optimized inversion‐recovery fat‐suppression techniques for T2‐weighted abdominal MR imaging
Authors: Lauenstein Thomas C. , Sharma Puneet , Hughes Timothy , Heberlein Keith , Tudorascu Dana , Martin Diego R. 
Published: May 2008

AbstractPurposeTo test the theoretical benefits of a spectral attenuated inversion‐recovery (SPAIR) fat‐suppression (FS) technique in clinical abdominal MRI by comparison to conventional inversion‐recovery (IR) FS combined with T2‐weighted (T2W) partial Fourier single shot fast spin echo (SSFSE).Materials and Methods1.5T MRI studies of the abdomen were performed in 28 patients with liver lesions (hemangiomas n = 14; metastases n = 14). T2W sequences were acquired using IR and SPAIR SSFSE. Measurements included retroperitoneal and mesenteric fat signal‐to‐noise (SNR) to evaluate FS; liver lesion contrast‐to‐noise (CNR) to evaluate bulk water signal recovery effects; and bowel wall delineation to evaluate susceptibility and physiological motion effects.ResultsSPAIR‐SSFSE images produce significantly improved FS and liver lesion CNR. The mean SNR of the retroperitoneal and mesenteric fat for SPAIR SSFSE was 20.5 ± 10.2 (±1 SD) and 12.7 ± 6.2, compared to 43.2 ± 24.1 (P = 0.000006) and 29.3 ± 16.8 (P = 0.0000005) for IR‐SSFSE. SPAIR‐SSFSE images produced higher CNR for both hemangiomas CNR = 164 ± 88 vs. 126 ± 83 (P = 0.00005) and metastases CNR = 75 ± 27 vs. 53 ± 19 (P = 0.007). Bowel wall visualization was significantly improved using SPAIR‐SSFSE (P = 0.002).ConclusionThe theoretical benefits of SPAIR over conventional IR FS translate into significant multiple improvements that can be measured on clinical abdominal MRI scans. J. Magn. Reson. Imaging 2008;27:1448–1454. © 2008 Wiley‐Liss, Inc.
Equivalent cross‐relaxation rate imaging of axillary lymph nodes in breast cancer
Authors: Mastsushima Shigeru , Nishiofuku Hideyuki , Iwata Hiroji , Era Seiichi , Inaba Yoshitaka , Kinosada Yasutomi 
Published: May 2008

AbstractPurposeTo determine whether equivalent cross‐relaxation rate (ECR) imaging (ECRI) is a feasible method for optimization of axillary lymph node dissection (ALND) and thereby improve quality‐of‐life (QOL).Materials and MethodsA total of 50 breast cancer patients underwent ECRI, with off‐resonance saturation pulse at frequency offset of 5 ppm. ECR threshold values were determined to evaluate metastases to lymph nodes in the ALND group before examining the relationship between ECR value and cellular density. Metastases to lymph nodes of the sentinel lymph node biopsy (SLNB) group were evaluated based on the results of the ALND group.ResultsIn the ALND group, regions without metastases showed a higher cellular density and ECR value than those with metastases. The relationship of ECR value to cellular density formed two clusters according to the presence or absence of metastasis; cellular density was related to ECR value for both clusters. In the SLNB group, supposing a threshold ECR value of 80%, sensitivity and specificity were 88.2% and 100%, respectively.ConclusionECRI is a potentially useful method for cellular density imaging of axillary lymph nodes. ECRI provides active information that enables ALND to be avoided, thus improving QOL. J. Magn. Reson. Imaging 2008;27:1278–1283. © 2008 Wiley‐Liss, Inc.
MRI measurement of change in vascular parameters in the 9L rat cerebral tumor after dexamethasone administration
Authors: Ewing James R. , Brown Stephen L. , Nagaraja Tavarekere N. , Bagher‐Ebadian Hassan , Paudyal Ramesh , Panda Swayamprava , Knight Robert A. , Ding Guangliang , Jiang Quan , Lu Mei , Fenstermacher Joseph D. 
Published: May 2008

AbstractPurposeTo demonstrate in the rat 9L cerebral tumor model that repeated MRI measurements can quantitate acute changes in the blood‐brain distribution of Gadomer after dexamethasone administration.Materials and MethodsA total of 16 Fischer 344 rats were studied at 7T, 15 days after cerebral implantation of a 9L tumor. MRI procedures employed a T‐One by Multiple Read Out Pulses (TOMROP) sequence to estimate R1 (R1 = 1/T1) at 145‐second intervals before and after administration of Gadomer (Bayer), a macromolecular contrast agent (CA). Two baseline studies preceded Gadomer administration and 10 subsequent R1 maps tracked CA concentration in blood and brain for 25 minutes. Thereafter, either dexamethasone (N = 10) or normal saline (N = 6) was administered intravenously. A total of 90 minutes later a second series of 12 TOMROP measurements of Gadomer distribution was performed. The influx constant, K1, plasma distribution volume, vD, backflux constant, kb, and interstitial space, ve, were determined, and the test‐retest differences of each of four vascular parameters were calculated.ResultsDexamethasone decreased K1 approximately 60% (P = 0.02), lowered kb and vD (P = 0.03 and P < 0.01, respectively), and marginally but insignificantly decreased ve.ConclusionThis noninvasive MRI technique can detect drug effects on blood‐brain transfer constants of CAs within two hours of administration. J. Magn. Reson. Imaging 2008;27:1430–1438. © 2008 Wiley‐Liss, Inc.
Late structural alterations of cerebral white matter in long‐term survivors of childhood leukemia
Authors: Dellani Paulo R. , Eder Stefan , Gawehn Joachim , Vucurevic Goran , Fellgiebel Andreas , Müller Matthias J. , Schmidberger Heinz , Stoeter Peter , Gutjahr Peter 
Published: May 2008

AbstractPurposeTo look for the presence and age‐dependence of late structural alterations of otherwise normal‐appearing cerebral gray and white matter after radiation and chemotherapy in adult survivors of acute lymphoblastic leukemia (ALL) during childhood.Materials and MethodsIn a group of 13 adult survivors 17–37 years old, who had been treated by total brain radiation (18–24 Gy) and chemotherapy 16–28 years ago, prospective MR examinations including diffusion tensor imaging (DTI) were performed. Evaluation included volumetry, calculation of mean diffusivity (MD) and fractional anisotropy (FA), and comparison of results to an age‐matched control group.ResultsDTI showed significantly reduced FA values in the temporal lobes (difference of 0.069 units, P < 0.001), hippocampi (difference of 0.033 units, P < 0.001), and thalami (difference of 0.046 units, P = 0.001), which were accompanied by significant white matter volume loss (difference of 92 cm3, P < 0.001). Significant elevations of MD were limited to the temporal white matter (difference of 42 × 10−6 mm2/s, P = 0.005). Global and frontal white matter MD correlated negatively to increasing age of the survivors (P < 0.01).ConclusionWith regard to structural white matter alterations, adult long‐term survivors of childhood ALL, who had received total brain radiation and chemotherapy, apparently show the same overall age dependence as controls. Follow‐up studies are needed for confirmation. J. Magn. Reson. Imaging 2008;27:1250–1255. © 2008 Wiley‐Liss, Inc.
Differential interictal activity of the precuneus/posterior cingulate cortex revealed by resting state functional MRI at 3T in generalized vs. Partial seizure
Authors: Lui Su , Ouyang Luo , Chen Qin , Huang Xiaoqi , Tang Hehan , Chen Huafu , Zhou Dong , Kemp Graham J. , Gong Qiyong 
Published: May 2008

AbstractPurposeTo characterize, using functional MRI (fMRI), the pattern of active brain regions in the resting state in patients with epilepsy.Materials and MethodsWe studied 28 patients with epilepsy, divided into a partial seizure (PS; N = 9) and a generalized seizure group (GS; N = 19), and 34 control subjects. Resting state fMRI was performed using a GE 3T scanner by collecting 200 volumes of echo‐planar imaging (EPI) images with subjects relaxed, eyes closed. Data were processed using a modification of the method of Fransson (Hum Brain Mapp 2005;26:15–29), which reveals information on regional low‐frequency Blood Oxygenation Level Dependent (BOLD) signal oscillations in the resting state without any a priori hypothesis. The significant active areas in brain were identified with both individual and group analysis.ResultsControls showed active regions in the precuneus/posterior cingulate cortex (PCC) and medial prefrontal cortex (MPFC)/ventral anterior cingulate cortex (vACC), theregions associated with the brain “default mode.” Similar active regions were observed in PS, whereas GS showed no significant activation of precuneus/PCC.ConclusionIn GS, the lack of activation in precuneus/PCC may partly account for their more severe interictal deficits, compared to PS, in cognitive functions such as concentration and memory. J. Magn. Reson. Imaging 2008;27:1214–1220. © 2008 Wiley‐Liss, Inc.
Improvement of vessel visibility in time‐of‐flight MR angiography of the brain
Authors: Shonai Takaharu , Carpenter Jeffrey S. , Lemieux Susan K. , Harada Kuniaki , Omori Kazumi , Kaneko Nobuaki , Fukushima Takanori 
Published: May 2008

AbstractPurposeTo improve vessel visibility in time‐of‐flight MR angiography (TOF‐MRA) by careful consideration of coil choice, coil position, and frequency offset and profile of the nonspatially selective chemical shift selective (CHESS) presaturation pulse.Materials and MethodsThe effects of both the CHESS and the excitation radiofrequency (RF) pulses on flow signal and signals from stationary substances were evaluated by changing the spatial area where RF pulses were applied to upstream flow in a flow phantom and in human subjects. The difference between the eight‐channel phased‐array receive‐only coil and the transmit–receive coil was evaluated.ResultsThe CHESS pulse suppresses the flow signal over a wider frequency range than the signals from stationary substances, especially when using the body coil for transmission. Even without presaturation pulse, the excitation pulse slightly suppressed the flow signal. Adjusting the position of the transmit–receive coil relative to the head improved these TOF‐MRA images. The results were better than those obtained with the eight‐channel coil.ConclusionThe excitation and the nonspatially selective CHESS pulses degraded the flow signal. Our results suggest that reduced spatial extent of RF pulse application to upstream flow can improve image quality of TOF‐MRA. This result can be implemented on conventional scanners. J. Magn. Reson. Imaging 2008;27:1362–1370. © 2008 Wiley‐Liss, Inc.
Fully automatic segmentation of the brain from T1‐weighted MRI using Bridge Burner algorithm
Authors: Mikheev Artem , Nevsky Gregory , Govindan Siddharth , Grossman Robert , Rusinek Henry 
Published: May 2008

AbstractPurposeTo validate Bridge Burner, a new brain segmentation algorithm based on thresholding, connectivity, surface detection, and a new operator of constrained growing.Materials and MethodsT1‐weighted MR images were selected at random from three previous neuroimaging studies to represent a spectrum of system manufacturers, pulse sequences, subject ages, genders, and neurological conditions. The ground truth consisted of brain masks generated manually by a consensus of expert observers. All cases were segmented using a common set of parameters.ResultsBridge Burner segmentation errors were 3.4% ± 1.3% (volume mismatch) and 0.34 ± 0.17 mm (surface mismatch). The disagreement among experts was 3.8% ± 2.0% (volume mismatch) and 0.48 ± 0.49 mm (surface mismatch). The error obtained using the brain extraction tool (BET), a widely used brain segmentation program, was 8.3% ± 9.1%. Bridge Burner brain masks are visually similar to the masks generated by human experts. Areas affected by signal intensity nonuniformity artifacts were occasionally undersegmented, and meninges and large sinuses were often falsely classified as the brain tissue. Segmentation of one MRI dataset takes seven seconds.ConclusionThe new fully automatic algorithm appears to provide accurate brain segmentation from high‐resolution T1‐weighted MR images. J. Magn. Reson. Imaging 2008;27:1235–1241. © 2008 Wiley‐Liss, Inc.
Sex differences in language processing: Functional MRI methodological considerations
Authors: Harrington Greg S. , Farias Sarah Tomaszewski 
Published: May 2008

AbstractPurposeTo evaluate the influence of both analysis methods and tasks used in the determination of language related sex differences. Previous neuroimaging studies evaluating sex differences in language processing have been inconsistent.Materials and MethodsThe current study compared FMRI activation between men and women on a variety of language tasks using different types of individual (laterality and activation volume) and group analyses to evaluate the effects of task and methodology. Forty subjects completed five language tasks, 19 men and 21 women.ResultsGroup analyses revealed greater activation for men compared with women in the left pars orbitalis while women showed greater activation within the right insula. With individual analyses, there were no significant sex differences in laterality using two large regions of interest (ROIs) covering the inferior frontal and temporoparietal regions; however, there were significant sex effects within small, specific ROIs (insula, middle temporal and pars opercularis, triangularis, and orbitalis). When holding the task constant, some methods (for example different ROIs within individual analyses) revealed sex differences while others methods did not, indicating a dependence on methodology.ConclusionThe results partly explain why FMRI studies evaluating language related sex effects have been inconsistent. J. Magn. Reson. Imaging 2008;27:1221–1228. © 2008 Wiley‐Liss, Inc.
Temporal evolution of MR perfusion in neonatal hypoxic‐ischemic encephalopathy
Authors: Wintermark Pia , Moessinger Adrien C. , Gudinchet François , Meuli Reto 
Published: May 2008

AbstractPurposeTo illustrate the evolution of brain perfusion‐weighted magnetic resonance imaging (PWI‐MRI) in severe neonatal hypoxic‐ischemic (HI) encephalopathy, and its possible relation to further neurodevelopmental outcome.Materials and MethodsTwo term neonates with HI encephalopathy underwent an early and a late MRI, including PWI. They were followed until eight months of age. A total of three “normal controls” were also included. Perfusion maps were obtained, and relative cerebral blood flow (rCBF) and cerebral blood volume (rCBV) values were measured.ResultsCompared to normal neonates, a hyperperfusion (increased rCBF and rCBV) was present on early scans in the whole brain. On late scans, hyperperfusion persisted in cortical gray matter (normalization of rCBF and rCBV ratios in white matter and basal ganglia, but not in cortical gray matter). Diffusion‐weighted imaging (DWI) was normalized, and extensive lesions became visible on T2‐weighted images. Both patients displayed very abnormal outcome: Patient 2 with the more abnormal early and late hyperperfusion being the worst.ConclusionPWI in HI encephalopathy did not have the same temporal evolution as DWI, and remained abnormal for more than one week after injury. This could be a marker of an ongoing mechanism underlying severe neonatal HI encephalopathy. Evolution of PWI might help to predict further neurodevelopmental outcome. J. Magn. Reson. Imaging 2008;27:1229–1234. © 2008 Wiley‐Liss, Inc.