bluuebunny/crossref_metadata_2025_split huggingface dataset:
MRI in characterization of focal liver lesions: Comparison of T2 weighting by conventional spin‐echo and turbo spin‐echo sequences
Authors: Giovagnoni Andrea , Paci Enrico , Valeri Gianluca , Ercolani Paola , Gesuita Rosaria , Carle Flavia , Piga Andrea 
Published: March 2007

AbstractForty‐one patients with 61 proved focal liver lesions underwent MRI of the liver at 1.0 T, with the aim of evaluating the usefulness of turbo spin‐echo (TSE) sequences in characterizing focal liver lesions, by comparing them with conventional spin‐echo (CSE) sequences. Two different TSE protocols were employed, with constant echo time and varying repetition time: TSE‐S (3000 msec) and TSE‐L (5100 msec). All images were evaluated quantitatively (signal‐to‐noise ratio ‘SNR’) and qualitatively: because benign lesions were all liquid (12 cysts and 10 hemangiomas), they were well characterized morphologically on the basis of signal intensity.Mean SNR was significantly different between metastases and benign lesions (P < .0001) with all T2 sequences. Among the single T2 sequences tested, logistic regression analysis showed TSE‐L to have the best predictive ability of the nature of focal lesions, with a G value of 42.02, compared to 29.87 of TSE‐S and 25.55 of CSE second echo (SE II). The combination of TSE‐L with TSE‐S did not modify these results, whereas the combination of TSE‐L with CSE only resulted in slight improvement (G = 46.95). Comparison of the receiver operating characteristic (ROC) curves showed only SE II (area under the ROC curve of .8312) to be significantly inferior to the best single sequence, or TSE‐L (area under the ROC curve of .9176; P = .027). All sequences were equivalent in qualitative evaluation, with good reproducibility, sensitivity ranging from .94 to 1.0, and specificity ranging from .86 to .93.This study confirms the value of TSE sequences in characterization of focal liver lesions. Time of acquisition is strongly reduced with these sequences, whereas results are fairly similar to those obtained with CSE. TSE sequences could therefore replace CSE for the study of focal liver lesions.
Dynamic contrast‐enhanced breath‐hold MR imaging of thoracic malignancy using cardiac compensation
Authors: Low Russell N. , Sigeti Joel S. , Song S. Y. Thomas , Shimakawa Ann , Pelc Norbert J. 
Published: March 2007

AbstractThe purpose of this paper was to evaluate the use of dynamic gadopentetate dimeglumine‐enhanced, breath‐hold spoiled gradient‐recalled (SPGR) MR imaging with cardiac compensation (CMON) compared to spin‐echo MR imaging in patients with thoracic malignancy. We retrospectively reviewed MR images from 29 patients with thoracic tumors. MR imaging included axial electrocardiogram (ECG)‐gated T1‐weighted, fast spin echo (FSE) T2‐weighted, and contrast‐enhanced breath‐hold fast multiplanar SPGR imaging with CMON, which selects the phase‐encoding gradient based on the phase within the cardiac cycle. Images were reviewed for lung masses, mediastinal or hilar tumor, disease of the pleura, chest wall, and bones, and vascular compression or occlusion. Contrast‐enhanced fast multiplanar SPGR imaging with CMON produces images of the chest that are free of respiratory artifact and have diminished vascular pulsation artifact. ECG‐gated T1‐weighted images were preferred for depicting mediastinal and hilar tumor. The gadopentetate dimeglumine‐enhanced fast multiplanar SPGR images were useful for depicting chest wall tumor, vascular compression or thrombosis, osseous metastases, and in distinguishing a central tumor mass from peripheral lung consolidation. Pleural tumor was depicted best on the FSE T2‐weighted images and the contrast‐enhanced SPGR images. As an adjunct to spin echo T1‐weighted and T2‐weighted imaging, contrast‐enhanced fast multiplanar SPGR imaging with CMON is useful in the evaluation of thoracic malignancy.
The effect of image resolution on vessel signal in high‐resolution magnetic resonance angiography
Authors: Parker Dennis L. , Parker Daniel J. , Blatter Duane D. , Du Yiping P. , Goodrich Kenneth C. 
Published: March 2007

AbstractIn this paper, the theoretical dependence of the signal of flowing fluids is considered in terms of the imaging parameters and the physical condition of the flowing fluid. For the vessel sizes, flow ranges, and imaging conditions studied, it is demonstrated that the fluid signal can be predicted from the solution of Bloch equations. For vessels on the order of the imaging resolution or smaller, the effects of the image resolution must be included.
Sonochemically produced fluorocarbon microspheres: A new class of magnetic resonance imaging agent
Authors: Webb Andrew G. , Wong Mike , Kolbeck Kenneth J. , Magin Richard L. , Suslick Kenneth S. 
Published: March 2007

AbstractWith the intent of increasing the signal‐to‐noise ratio (SNR) of fluorine magnetic resonance imaging and enabling new applications, we have developed a novel class of agents based on protein encapsulation of fluorocarbons. Microspheres formed by high‐intensity ultrasound have a gaussian size distribution with an average diameter of 2.5 μm. As with conventional emulsions, these microspheres target the reticuloendothelial system. However, our sonochemically produced microspheres, because of a high encapsulation efficiency, show increases in the SNR of up to 300% compared to commercially available emulsions. We also demonstrate an increase in the circulation life‐time of the microspheres within the bloodstream by more than 30‐fold with a chemical modification of the outer surface of the microsphere. Finally, by encapsulating mixtures of fluorocarbons that undergo solid/liquid phase transitions, we can map temperature in the reticuloendothelial system, with signal changes of approximately 20‐fold over a 5°C range.
HASTE MR imaging: Description of technique and preliminary results in the abdomen
Authors: Semelka Richard C. , Kelekis Nikolaos L. , Thomasson David , Brown Mark A. , Laub Gerhard A. 
Published: March 2007

AbstractHASTE (HAlf fourier Single‐shot Turbo spin‐Echo) is a single‐section T2‐weighted sequence that acquires images in less than 1 second. Images are breathing independent and possess a variety of other features useful for imaging the abdomen. The design of this technique is described. Clinical studies of 38 consecutive patients were performed using this technique. HASTE images were considered good in 28 and fair in 10 patients, including five patients who could not suspend respiration. Definition of liver and bowel was particularly clear.
Lesion volume measurement in multiple sclerosis: How important is accurate repositioning?
Authors: Gawne‐Cain Mary L. , Webb Stephanie , Tofts Paul , Miller David H. 
Published: March 2007

AbstractThis study was designed to estimate the contribution of repositioning inaccuracies to measured intracranial lesion volumes in multiple sclerosis (MS). Five patients with MS were each scanned 10 times, using spin‐echo imaging (2,000/34/90), contiguous 5‐mm slices, and different scanning positions. The maximum displacements from baseline were ±4° (AP rotation) and 3 mm (slice offset). Lesion volume was measured twice for each scan using a semiautomated contour technique. Measured lesion volumes ranged from 4,328 mm3 to 164,831 mm3. The mean intrarater coefficient of variation (CV) calculated for individual patients ranged from 1.1 to 4% (median, 1.7%). Using analysis of variance, the overall variance and CV due to altered scan position were greater than that due to rater error (repositioning CV 4.0%, intrarater CV 3.5%). The worst‐case difference between volumes in the same patient ranged from 8.9 to 32% (median, 9.9%). Both rater and repositioning errors were greater for smaller lesion volumes. The maximum potential error due to repositioning inaccuracies is of a similar magnitude to the 5 to 10% expected change in lesion volume over 1 year. This study justifies continued careful attention to accuracy in repositioning for serial MR studies in patients with MS.
Assessment of cerebral blood flow reserve using functional magnetic resonance imaging
Authors: Hedera Peter , Lai Song , Lewin Jonathan S. , Haacke E. Mark , Wu Dee , Lerner Alan J. , Friedland Robert P. 
Published: March 2007

AbstractImaging of activated brain areas based on changes of blood deoxyhemoglobin levels is now possible with MRI. Acetazolamide (ACZ) increases cerebral blood flow (CBF) without changing cerebral oxygen consumption; this results in signal changes observed in gradient echo MR images from the areas with an increase in CBF. We assessed signal changes after ACZ application in seven healthy subjects with a conventional 1.5‐T MRI scanner. The susceptibility‐sensitized three‐dimensional fast low‐angle shot (FLASH) sequence was used to visualize signal changes induced by ACZ. We analyzed anatomic localization of different ranges of detected signal changes. ACZ caused significant signal changes in the gray matter and at the edge of the cerebral cortex, the latter corresponding to draining surface veins. No significant differences were seen among different brain areas within the same slice. Using the maximum intensity projection technique, we were able to partially separate signal changes originating in draining veins from signal originating in the gray matter microvasculature. Signal changes from the microvessels reflect cerebrovascular reserve. Blood‐oxygen‐level‐dependent (BOLD) based MRI can evaluate CBF reserve with high spatial and temporal resolution. To assess cerebrovascular reserve, it is necessary to separate signal changes originating in large vessels from signal from brain microvasculature.
Hypogenetic lung syndrome: Functional and anatomic evaluation with magnetic resonance imaging and magnetic resonance angiography
Authors: Vrachliotis Thomas G. , Bis Kostaki G. , Shetty Anil N. , Simonetti Orlando , Madrazo Beatrice 
Published: March 2007

AbstractA case of hypogenetic lung syndrome is described in which anatomic and functional information was obtained with use of ECG‐triggered turbo (fast) spin‐echo, cine, velocity‐encoded cine, and contrast‐enhanced magnetic resonance angiography (MRA) sequences. To the best of our knowledge, a complete functional and anatomic study of hypogenetic lung syndrome with MRI has not been previously reported.
A solid reusable endorectal receiver coil for magnetic resonance imaging of the prostate: Design, use, and comparison with an inflatable endorectal coil
Authors: Desouza Nandita M. , Gilderdale David J. , Puni Rakesh , Coutts Glyn A. , Young Ian R. 
Published: March 2007

AbstractWe have designed a solid endorectal receiver coil for MRI of the prostate. The coil provided an improved signal‐to‐noise ratio up to 5 cm from its surface when compared with a standard pelvic phased array. This preliminary report describes 16 patients who were imaged using this coil, seven of whom had been examined previously with a balloon‐design endorectal coil. Patient tolerance of these coils was compared. The solid coil was easy to insert and quick to set up because it did not require external tuning and matching. It avoided uncomfortable rectal distension experienced with the balloon coil as well as susceptibility artifacts from air in the balloon. In addition, it could be sterilized and reused.
Fast MR imaging techniques: Impact in the abdomen
Authors: Mitchell Donald G. 
Published: March 2007

AbstractThe increased efficiency of MRI data acquisition has had a substantial impact on clinical MRI of the abdomen. Five particular applications that have thus been affected include breath‐hold imaging of liver lesions (including detection, characterization, and biopsy), MR cholangiopan‐ creatography, practical chemical shift imaging (including liver and adrenal glands), dynamic imaging after contrast media injection, and MR angiography.
CT and MRI of stroke
Authors: Bahn Mark M. , Oser Allen B. , Cross Dewitte T. 
Published: March 2007

AbstractA review of the CT and MRI features of stroke imaging is presented. The pathophysiology of stroke is discussed as a basis for understanding the neuroimaging findings. Neuroimaging is divided according to the time interval between ictus and imaging: hyperacute, acute, subacute, and chronic. Newer MR stroke imaging techniques such as perfusion imaging and diffusion‐weighted imaging are presented.
The role of T2‐weighted fast‐spin‐echo imaging in the diagnosis of meniscal tears
Authors: White Lawrence M. , Schweitzer Mark E. , Johnson William J. , Amster Bernard J. , Oliveri Marcelino P. , Russell Karen 
Published: March 2007

AbstractThe objective of this study was to compare the accuracy of T2‐weighted fast‐spin‐echo (FSE) and intermediate‐weighted spin‐echo (SE) MR imaging in the detection of meniscal tears. Seventy‐six patients (152 menisci) who had arthroscopic surgery after MR imaging of the knee were studied. MR imaging included intermediate‐weighted SE and T2‐weighted FSE sequences. The use of intermediate‐weighted conventional SE images, T2‐weighted FSE images, and a combination of both sequences were evaluated in the detection of meniscal tears. T2‐weighted FSE imaging was slightly less accurate than intermediate‐weighted SE imaging in the diagnosis of meniscal tears. Interpretation of the menisci using both intermediate‐weighted SE and T2‐weighted FSE imaging did not improve the accuracy over intermediate‐weighted imaging evaluated in isolation.
Chondromalacia of the knee: Evaluation with a fat‐suppression three‐dimensional SPGR imaging after intravenous contrast injection
Authors: Suh Jin‐Suck , Cho Jae‐Hyun , Shin Kyoo‐Ho , Kim Sung Jae 
Published: March 2007

AbstractTwenty‐one MRI studies with a fat‐suppression three‐dimensional spoiled gradient‐recalled echo in a steady state (3D SPGR) pulse sequence after intravenous contrast injection were evaluated to assess the accuracy in depicting chondromalacia of the knee. On the basis of MR images, chondromalacia and its grade were determined in each of five articular cartilage regions (total, 105 regions) and then the results were compared to arthroscopic findings. The sensitivity, specificity, and accuracy of MRI were 70%, 99%, and 93%, respectively. MR images depicted 7 of 11 lesions of arthroscopic grade 1 or 2 chondromalacia, and seven of nine lesions of arthroscopic grade 3 or 4 chondromalacia. The cartilage abnormalities in all cases appeared as focal lesions with high signal intensity. Intravenous contrast‐injection, fat‐suppression 3D SPGR imaging showed high specificity in excluding cartilage abnormalities and may be considered as an alternative to intra‐articular MR arthrography when chondromalacia is suspected.
Theory and application of static field inhomogeneity effects in gradient‐echo imaging
Authors: Reichenbach Jürgen R. , Venkatesan Ramesh , Yablonskiy Dmitriy A. , Thompson Michael R. , Lai Song , Haacke E. Mark 
Published: March 2007

AbstractThe influence of local static magnetic field inhomogeneities on gradient‐echo imaging is discussed and the underlying theoretical aspects are reviewed. A high‐resolution approach is suggested to suppress image distortion and restore signal loss due to spin dephasing. Acquisition of three‐dimensional data sets not only overcomes part of the limitations associated with gradient echoes but also makes it possible to extract local information about the strength or direction of background gradients and relative susceptibility changes between different tissues. Applications of the suggested approach in the human brain for anatomical imaging as well as for extraction of physical and physiological parameters are presented and discussed.
Contrast‐enhanced MRA in pre‐embolization assessment of a pulmonary arteriovenous malformation
Authors: Vrachliotis Thomas G. , Bis Kostaki G. , Kirsch Matthias J. , Shetty Anil N. 
Published: March 2007

AbstractWe describe a case of a single pulmonary vascular malformation studied with a new contrast‐enhanced three‐dimensional MRA technique. Images provided the interventional radiologist with a pre‐embolization road map from which information regarding the number and size of feeding and draining vessels was obtained accurately and noninvasively.
Nutritional comparison of fresh, frozen, and canned fruits and vegetables II. Vitamin A and carotenoids, vitamin E, minerals and fiber
Authors: Rickman Joy C , Bruhn Christine M , Barrett Diane M 
Published: March 2007

AbstractIn this second part of our review, we examine the literature for changes in carotenoids, vitamin E, minerals, and fiber due to processing, storage, and cooking of fresh, frozen, and canned fruits and vegetables. While inconsistencies in methodology and reporting methods complicate interpretation of the data, the results show that these nutrients are generally similar in comparable fresh and processed products. The higher levels of carotenoids typically found in canned as compared to fresh products may be attributed to either reporting results on a wet rather than dry weight basis, greater extractability, or differences in cultivars. There are relatively few studies on processing, storage, and cooking effects on vitamin E in fruits and vegetables. Further research is needed to understand nutritional changes in those few fruits and vegetables rich in vitamin E, such as tomatoes. Minerals and fiber are generally stable to processing, storage, and cooking, but may be lost in peeling and other removal steps during processing. Mineral uptake (e.g., calcium) or addition (e.g., sodium) during processing can change the natural mineral composition of a product. Sodium concerns in canned food can be addressed by choosing products with no salt added. Since nutrient content varies considerably by commodity, cultivar, and postharvest treatments, inclusion of a wide variety of fruits and vegetables in the diet is encouraged. Copyright © 2007 Society of Chemical Industry
Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds
Authors: Rickman Joy C , Barrett Diane M , Bruhn Christine M 
Published: March 2007

AbstractThe first of a two‐part review of the recent and classical literature reveals that loss of nutrients in fresh products during storage and cooking may be more substantial than commonly perceived. Depending on the commodity, freezing and canning processes may preserve nutrient value. The initial thermal treatment of processed products can cause loss of water‐soluble and oxygen‐labile nutrients such as vitamin C and the B vitamins. However, these nutrients are relatively stable during subsequent canned storage owing to the lack of oxygen. Frozen products lose fewer nutrients initially because of the short heating time in blanching, but they lose more nutrients during storage owing to oxidation. Phenolic compounds are also water‐soluble and oxygen‐labile, but changes during processing, storage and cooking appear to be highly variable by commodity. Further studies would facilitate the understanding of the changes in these phytochemicals. Changes in moisture content during storage, cooking and processing can misrepresent changes in nutrient content. These findings indicate that exclusive recommendations of fresh produce ignore the nutrient benefits of canned and frozen products. Nutritional comparison would be facilitated if future research would express nutrient data on a dry weight basis to account for changes in moisture. Copyright © 2007 Society of Chemical Industry
Chemical fingerprint and quantitative analysis of Fructus Psoraleae by high‐performance liquid chromatography
Authors: Qiao Chun‐Feng , Han Quan‐Bin , Song Jing‐Zheng , Mo Shi‐Fu , Kong Ling‐Dong , Kung Hsiang‐Fu , Xu Hong‐Xi 
Published: March 2007

AbstractFructus Psoraleae, a widely used traditional Chinese medicine, is well known as a health supplement ingredient. In our study, an improved and comprehensive HPLC fingerprint of Fructus Psoraleae was established. Two important new benzofuran glycosides, psoralenoside and isopsoralenoside, were identified as characteristic constituents for the first time. HPLC separation was performed on an RP‐C8 column. The mobile phase was acetonitrile and 0.1% acetic acid solution with linear gradient change of acetonitrile from 10 to 82% in 40 min. The flow rate was 1.0 mL/min, and the detection wavelength was set at 310 nm. The HPLC chromatograms of twenty‐six samples from different regions of China showed a similar pattern. Twelve peaks were selected as characteristic peaks and further identified as psoralenoside, isopsoralenoside, psoralen, isopsoralen, bavachromene, corylifolin, corylin, psoralidin, isobavachalcone, bavachinin, corylifol A, and bakuchiol, respectively. Nine of them were simultaneously quantitatively analyzed for the first time. A more comprehensive analytical method was established for the fingerprint of Fructus Psoraleae. It is very useful for authentication and quality assessment of the crude drug.
Studies on degradation of imazalil enantiomers in soil using capillary electrophoresis
Authors: Chu Bao‐Lin , Guo Bao‐Yuan , Peng Zhenlei , Wang Zhihua , Guo Guangsheng , Lin Jin‐Ming 
Published: March 2007

AbstractA scheme was demonstrated to elucidate the degradation behaviors of the two enantiomers of the fungicide imazalil in soil using cyclodextrin‐modified capillary zone electrophoresis. The separation buffer was 50 mmol/L NaH2PO4, 5 mmol/L (NH4)H2PO4, and 5 mmol/L β‐cyclodextrin (pH 3.0). The limits of detection of this CE method were 0.24 and 0.26 μg/mL for (–)‐ and (+)‐imazalil, respectively. Five different soil conditions were investigated in laboratory microcosms: under sunlight; in darkness; under UV irradiation; in sterilized soil; and in soil with wheat planted in it. Radiation, microorganisms, and uptake by wheat benefited the degradation of imazalil in this study. The half‐lives (t1/2) of imazalil in soil under the above conditions were 20, 30.5, 11, 27.5, and 21.5 days, respectively. The degradation rate of imazalil in soil under the five different sets of conditions decreased in the order: UV irradiation > sunlight > soil with wheat planted in it > sterilized soil > soil kept in darkness. Imazalil in soil (pH 8.2, slightly alkaline) collected in the suburbs showed non‐enantioselective degradation.
Rapid qualitative and quantitative analyses of flavanone aglycones in Fructus aurantii by HPLC ion‐trap MS
Authors: Zhou Da‐yong , Xu Qing , Xue Xing‐ya , Zhang Fei‐fang , Jing Yu , Liang Xin‐miao 
Published: March 2007

AbstractIT‐MS operated in the positive mode was applied for the rapid characterization/quantification of the flavanones in extracts from Fructus aurantii. APCI‐MS and CID MS/MS provide unequivocal molecular weight (MW) data of these compounds and useful information about their structures (diagnostic fragment ions). Main fragment pathways include neutral losses of H2O, C2H2O, and B‐ring as well as a retro‐Diels‐Alder (RDA) fragment giving rise to [1,3A + H]+, [1,3B + H]+, and [1,4B–H2 + H]+ ions, which form the characteristic MS/MS “fingerprint” of flavanone aglycones. When screening extracts of F. aurantii for flavanone aglycones, eight target compounds were characterized using this fingerprint. Meanwhile, ESI‐MS in full‐scan mode was developed and validated for the quantification of the main flavanone aglycones in F. aurantii. This method is simple, accurate, fast and requires only 16 min per sample for direct detection and quantification of naringenin and hesperetin. All the results and these characteristic fragments showed that the IT‐MS is a powerful tool for the structural characterization and quantitative determination of flavanone aglycones.