bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro investigation of pacemaker lead heating induced by magnetic resonance imaging: Role of implant geometry
Authors: Calcagnini Giovanni , Triventi Michele , Censi Federica , Mattei Eugenio , Bartolini Pietro , Kainz Wolfgang , Bassen Howard I. 
Published: September 2008

AbstractPurposeTo evaluate the effect of the geometry of implantable pacemakers (PMs) on lead heating induced by magnetic resonance imaging (MRI).Materials and MethodsIn vitro experiments were conducted with two different setups, using fluoroptic probes to measure the temperature increase. The first experiment consisted of a rectangular box filled with a gelled saline and a pacemaker with its leads. This box was exposed in an MRI birdcage coil to a sinusoidal 64‐MHz field with a calibrated whole‐body specific absorption rate (WB‐SAR) of 1 W/kg. The highest SAR and temperature increase (3000 W/kg, 12°C) occurred for the implant configuration having the largest area. The second experimental setup consisted of a human‐shaped torso filled with gelled saline. In this setup the PM and its lead were exposed to a real MRI scanner, using clinical sequences with WB‐SAR up to 2 W/kg.ResultsWe found that higher heating occurs for configurations with longer exposed lead lengths and that right chest PMs showed the highest temperature and local SAR (11.9°C, 2345 W/kg), whereas the left chest PMs were less heated (6.3°C, 1362 W/kg). Implant geometry, exposed lead length, and lead area must be considered in the wide variation of temperature increases induced by MRI.ConclusionsThe amount of MRI‐induced lead tip heating depends strongly on implant geometry, particularly the lead area, exposed lead length, and position of the implant in the phantom. Critical lead tip heating was found for the longer leads. Therefore, to minimize MRI‐induced lead tip heating, the PM lead should be as short as possible. J. Magn. Reson. Imaging 2008;28:879–886. © 2008 Wiley‐Liss, Inc.
Evaluation of motion correction effect and image quality with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) and parallel imaging acquisition technique in the upper abdomen
Authors: Hirokawa Yuusuke , Isoda Hiroyoshi , Maetani Yoji S. , Arizono Shigeki , Shimada Kotaro , Togashi Kaori 
Published: September 2008

AbstractPurposeTo evaluate motion correction effect and image quality in the upper abdomen with the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) (BLADE) and parallel imaging acquisition technique.Materials and MethodsA total of 50 consecutive patients underwent abdominal MR imaging. Fat‐saturated T2‐weighted turbo spin‐echo sequences were obtained by respiratory triggering. The subjects were examined with three different conditions of echo train length (ETL), blade width, and percent k‐space coverage in the same scanning time: 19/30/100%, 30/30/100%, and 30/52/175%, which were designated as L/C(1), L/C(2), and L/C(3), respectively. The parallel imaging acquisition technique was used to either reduce ETL from 30 to 19 in L/C(1) or increase k‐space coverage from 100% to 175% in L/C(3) compared with L/C(2). Motion and streak artifacts, and overall image quality were evaluated visually by two radiologists, independently.ResultsMotion and streak artifacts were mostly reduced in L/C(3) condition. The L/C(3) image also gave the best overall image quality compared with other conditions (P < 0.001). The inter‐rater reliability for each evaluation agreed well.ConclusionIn upper abdominal BLADE MRI, it was possible to reduce image artifacts and obtain better image quality by increasing the k‐space coverage with parallel imaging in the same scanning time. J. Magn. Reson. Imaging 2008;28:957–962. © 2008 Wiley‐Liss, Inc.
Magnetic resonance imaging and spectroscopy for monitoring liver steatosis
Authors: Cowin Gary J. , Jonsson Julie R. , Bauer Judith D. , Ash Susan , Ali Azmat , Osland Emma J. , Purdie David M. , Clouston Andrew D. , Powell Elizabeth E. , Galloway Graham J. 
Published: September 2008

AbstractPurposeTo compare noninvasive MRI and magnetic resonance spectroscopy (MRS) methods with liver biopsy to quantify liver fat content.Materials and MethodsQuantification of liver fat was compared by liver biopsy, proton MRS, and MRI using in‐phase/out‐of‐phase (IP/OP) and plus/minus fat saturation (±FS) techniques. The reproducibility of each MR measure was also determined. An additional group of overweight patients with steatosis underwent hepatic MRI and MRS before and after a six‐month weight‐loss program.ResultsA close correlation was demonstrated between histological assessment of steatosis and measurement of intrahepatocellular lipid (IHCL) by MRS (rs = 0.928, P < 0.0001) and MRI (IP/OP rs = 0.942, P < 0.0001; FS rs = 0.935, P < 0.0001). Following weight reduction, four of five patients with >5% weight loss had a decrease in IHCL of ≥50%.ConclusionThese findings suggest that standard MRI protocols provide a rapid, safe, and quantitative assessment of hepatic steatosis. This is important because MRS is not available on all clinical MRI systems. This will enable noninvasive monitoring of the effects of interventions such as weight loss or pharmacotherapy in patients with fatty liver diseases. J. Magn. Reson. Imaging 2008;28:937–945. © 2008 Wiley‐Liss, Inc.
Three‐dimensional fast spoiled gradient‐echo dual echo (3D‐FSPGR‐DE) with water reconstruction: Preliminary experience with a novel pulse sequence for gadolinium‐enhanced abdominal MR imaging
Authors: Low Russell N. , Panchal Neeraj , Vu Anthony T. , Knowles Adrian , Estkowski Lloyd , Slavens Zachary , Ma Jingfei 
Published: September 2008

AbstractPurposeTo compare three‐dimensional fast spoiled gradient‐echo dual‐echo (3D‐FSPGR‐DE) with water reconstruction to conventional 3D‐FSPGR for gadolinium‐enhanced abdominal imaging.Materials and MethodsSixty‐five patients underwent abdominal MRI on a 1.5T GE‐HDx MR scanner using gadolinium‐enhanced 3D‐FSPGR and 3D‐FSPGR‐DE imaging. Qualitatively, FSPGR‐DE and 3D‐FSPGR images were reviewed side by side for normal anatomic structures, artifacts, and image quality. The images were reviewed separately for abnormalities of abdominal organs. Receiver operating characteristic (ROC) curve analysis was performed. Quantitative analysis measured mean signal intensity of liver, spleen, aorta, liver lesions, and noise.ResultsObservers preferred FSPGR‐DE for evaluating liver, vessels, muscles, and subcutaneous tissues. Fat suppression was superior on FSPGR‐DE in 63 (0.97) and 61 (0.94) of 65 cases for two observers. FSPGR‐DE showed less susceptibility artifact in 47 (0.72) and 41 (0.63) cases, better signal in edge slices in 60 (0.92) and 60 (0.92) cases, less phase artifact in 42 (0.65) and 45 (0.69) cases, and less parallel imaging artifact in 13 (0.20) and 10 (0.15) cases. Images were equivalent for depicting abdominal findings with no difference in the area under the ROC curve. FSPGR‐DE images showed a 20%, 29%, and 34% increase in liver, splenic, and aortic signal, respectively, and a 45% and 62% increase in liver‐lesion contrast and contrast‐to‐noise ratio (CNR), respectively.ConclusionGadolinium‐enhanced 3D‐FSPGR‐DE with water reconstruction provides volumetric abdominal imaging with superior image quality, more homogeneous fat suppression, reduced artifacts, and improved image signal and homogeneity. J. Magn. Reson. Imaging 2008;28:946–956. © 2008 Wiley‐Liss, Inc.
Steady‐state free‐precession (SSFP) cine MRI in distinguishing normal and bicuspid aortic valves
Authors: Gleeson Tadhg G. , Mwangi Irene , Horgan Stephen J. , Cradock Andrea , Fitzpatrick Patricia , Murray John G. 
Published: September 2008

AbstractPurposeTo assess the diagnostic sensitivity and specificity of double‐oblique true fast imaging with steady‐state precession (SSFP) cine MRI in distinguishing normal and bicuspid aortic valves.Materials and MethodsEchocardiograms on patients referred for MRI of the heart and thoracic aorta over a four‐year period were reviewed retrospectively. A total of 17 patients with bicuspid aortic valve were identified and compared to 21 randomly chosen control patients. All patients had double‐oblique SSFP (True FISP) cine MRI of the aortic valve independently assessed by two radiologists in a blinded fashion, and graded as bicuspid or normal. Image quality was graded as 1, 2, or 3. Discordance was resolved by consensus.ResultsA total of 38 cases were reviewed (27 men, 11 women; age range = 15–67 years, mean = 25.33 years). Interobserver agreement was 0.97 (36/38 cases). One case of normal tricuspid valve was reported as bicuspid by both readers (false‐positive). All cases in which disparity arose were rated suboptimal by both readers (grade 2 or 3). Consensus review yielded sensitivity = 100%, specificity = 95.2%, positive predictive value = 94.4%, and negative predictive value = 100%; overall diagnostic accuracy was 97.36%. Interobserver agreement was 0.97.ConclusionDouble‐oblique TrueFISP cine MR imaging of the aortic valve is 100% sensitive and 95% specific in distinguishing normal and bicuspid aortic valves. J. Magn. Reson. Imaging 2008;28:873–878. © 2008 Wiley‐Liss, Inc.
Specific absorption rate studies of the parallel transmission of inner‐volume excitations at 7T
Authors: Zelinski Adam C. , Angelone Leonardo M. , Goyal Vivek K. , Bonmassar Giorgio , Adalsteinsson Elfar , Wald Lawrence L. 
Published: September 2008

AbstractPurposeTo investigate the behavior of whole‐head and local specific absorption rate (SAR) as a function of trajectory acceleration factor and target excitation pattern due to the parallel transmission (pTX) of spatially tailored excitations at 7T.Materials and MethodsFinite‐difference time domain (FDTD) simulations in a multitissue head model were used to obtain B1+ and electric field maps of an eight‐channel transmit head array. Local and average SAR produced by 2D‐spiral‐trajectory excitations were examined as a function of trajectory acceleration factor, R, and a variety of target excitation parameters when pTX pulses are designed for constant root‐mean‐square excitation pattern error.ResultsMean and local SAR grow quadratically with flip angle and more than quadratically with R, but the ratio of local to mean SAR is not monotonic with R. SAR varies greatly with target position, exhibiting different behaviors as a function of target shape and size for small and large R. For example, exciting large regions produces less SAR than exciting small ones for R ≥4, but the opposite trend occurs when R <4. Furthermore, smoother and symmetric patterns produce lower SAR.ConclusionMean and local SAR vary by orders of magnitude depending on acceleration factor and excitation pattern, often exhibiting complex, nonintuitive behavior. To ensure safety compliance, it seems that model‐based validation of individual target patterns and corresponding pTX pulses is necessary. J. Magn. Reson. Imaging 2008;28:1005–1018. © 2008 Wiley‐Liss, Inc.
Initial clinical experience with a new MRI vacuum‐assisted breast biopsy device
Authors: Mahoney Mary C. 
Published: September 2008

AbstractPurposeTo report initial clinical experience with a new previously unreported vacuum‐assisted device (EnCor MR, SenoRx, Aliso Viejo, CA) for magnetic resonance imaging (MRI)‐guided breast biopsy and to compare this device with previously reported technologies.Materials and MethodsA prospective study of MRI‐guided vacuum‐assisted breast biopsies using the EnCor device was undertaken. Lesions targeted for biopsy were occult on mammography, ultrasound, and physical examination. Histologic results were obtained for all cases. Patients with benign, concordant results underwent clinical and imaging follow‐up. Cases with discordant, high‐risk, or malignant results were referred for surgical biopsy.ResultsA total of 55 biopsies were performed in 47 patients. All biopsies were technically successful. Histologic results yielded malignancy in 10 (10/55, 18%) of the 55 lesions and high‐risk or atypical lesions in 7 (7/55, 13%) of the cases. All of these patients have had surgical follow‐up, with four (4/55, 7%) underestimations. There were three (3/55, 5%) discordant cases. 35 (35/55, 64%) lesions yielded benign concordant results. Of these, six (6/35, 17%) lesions were removed surgically, with confirmation of the MR‐guided biopsy results. Twenty (20/35, 57%) lesions have undergone at least 6‐month follow‐up MRI, with resolution or stability of the MRI findings.ConclusionThe EnCor breast biopsy device has comparable results to those previously reported for other MRI‐guided vacuum‐assisted technologies. J. Magn. Reson. Imaging 2008;28:900–905. © 2008 Wiley‐Liss, Inc.
Dynamic perfusion MRI: Capability for evaluation of disease severity and progression of pulmonary arterial hypertension in patients with connective tissue disease
Authors: Ohno Yoshiharu , Koyama Hisanobu , Nogami Munenobu , Takenaka Daisuke , Matsumoto Sumiaki , Onishi Yumiko , Matsumoto Keiko , Murase Kenya , Sugimura Kazuro 
Published: September 2008

AbstractPurposeTo prospectively evaluate the capability of dynamic perfusion MRI for assessment of disease severity and progression to pulmonary arterial hypertension (PAH) in connective tissue disease (CTD) patients.Materials and MethodsIn all, 18 gender‐ and age‐matched CTD patients without and with PAH and nine healthy volunteers underwent dynamic perfusion MRI, Doppler echocardiography, and pulmonary function test. Disease severity of CTD was assessed in terms of diffusing capacity for carbon monoxide (%DLCO) and estimated systolic pulmonary arterial pressure (sPAP), and progression of PAH in terms of pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). From calculated pulmonary perfusion parameter maps, means of pulmonary blood flow (mPBF), pulmonary blood volume (mPBV), and mean transit time (mMTT) were determined as averages of all region of interest (ROI) measurements. To determine disease severity in CTD, all parameters were statistically correlated with sPAP and %DLCO. To determine progression to PAH, all parameters were statistically correlated with mPAP and PVR.ResultsAll pulmonary perfusion parameters correlated significantly with sPAP and %DLCO (P < 0.05). mPBF and mPBV correlated significantly with mPAP and moderately with PVR (P < 0.05).ConclusionDynamic perfusion MRI can be used for assessment of disease severity and progression of PAH in CTD patients. J. Magn. Reson. Imaging 2008;28:887–899. © 2008 Wiley‐Liss, Inc.
Multicenter trial: Comparison of two different formulations and application systems of low‐dose nasal midazolam for routine magnetic resonance imaging of claustrophobic patients
Authors: Tschirch Frank T.C. , Suter Katja , Froehlich Johannes M. , Studler Ueli , Nidecker Andreas , Eckhardt Boris , Beranek‐Chiu Jan , Surber Christian , Weishaupt Dominik 
Published: September 2008

AbstractPurposeTo prospectively assess and compare two formulations and methods of administration of low‐dose nasal midazolam for the treatment of claustrophobic patients undergoing magnetic resonance imaging (MRI) as part of a multicenter Phase III trial.Materials and MethodsIn all, 108 consecutive adult claustrophobic patients were randomly assigned to one of two treatment groups (multidose group: MDG, unit‐dose group: UDG). MDG encompassed 55 patients who received intranasally a 0.5% midazolam formulation into each nostril (total dose, 1.0 mg), whereas the 53 patients in UDG received a 1% midazolam formulation into only one nostril (total dose, 1.0 mg). This initial dose could be repeated once. Patient tolerance and anxiety were assessed using a questionnaire and a visual analog scale immediately before and after MRI. Image quality was evaluated using a five‐point scale.ResultsIn all, 53/55 MR examinations (96%) with MDG and 52/53 (98%) with UDG were completed successfully. The dose of 1 mg had to be repeated significantly less often in UDG compared to MDG (4/53, 8% vs. 13/55, 24%; P = 0.003). The image quality of all MR examinations was rated good to excellent, and slightly better in UDG (P = 0.045).ConclusionNasally applied low‐dose midazolam is a patient‐friendly solution to facilitate MRI of claustrophobicpatients. The nasal spray of UDG is superior to that of MDG with a necessity of additional dosing. J. Magn. Reson. Imaging 2008;28:866–872. © 2008 Wiley‐Liss, Inc.
Kidney transplantation: Structural and functional evaluation using MR Nephro‐Urography
Authors: Kalb Bobby , Martin Diego R. , Salman Khalil , Sharma Puneet , Votaw John , Larsen Christian 
Published: September 2008

AbstractEnd‐stage‐renal disease (ESRD) is a major health issue in the United States, and the Medicare costs of ESRD totaled nearly $21 billion in 2005. Renal transplantation has emerged as the treatment of choice in this patient population, providing improved quality of life and lower healthcare costs compared with other treatment options. Imaging evaluation of a graft kidney plays a critical role in the postoperative care of the renal transplant patient. In the past, diagnostic evaluation of the transplant kidney has depended upon a combination of ultrasonography, computed tomography, MRI, and biopsy, used in conjunction with the patient's clinical presentation. However, new and developing advances in MR technology has lead to the development of MR Nephro‐Urography (MRNU), which provides both anatomic and functional evaluation of the kidney in a single examination. It is expected that the increasing use of MRNU will have a significant impact on the management of renal transplant patients. This review describes MRNU methodology, examines known posttransplant complications, and highlights the utility of MRNU as a comprehensive imaging examination to diagnose both surgical and medical complications of the transplant kidney. J. Magn. Reson. Imaging 2008;28:805–822. © 2008 Wiley‐Liss, Inc.
Diurnal variations of precipitation during the warm season over China
Authors: Yin Shuiqing , Chen Deliang , Xie Yun 
Published: September 2008

AbstractThe spatial distribution and seasonal change of diurnal variations of precipitation during the warm season (May–September) over China were analysed using hourly data from 62 rain gauges during 1954–2001. Nocturnal precipitation predominates for the stations over the Tibetan Plateau as well as in south‐west and north‐west China. For stations to the east of about 110°E, daytime precipitation predominates in the northern and southern parts, whereas nocturnal precipitation predominates in the middle and lower reaches of the Yangtze River and the North China Plain. Further, the magnitude of diurnal variations first decreases and then increases from the south towards the north. Two stations located close to the Bohai Bay manifest morning maxima. The significant diurnal variations in vertical circulation (stronger during the day and weaker at night), the meso‐local‐scale mountain‐valley winds, and the nighttime cooling of cloud tops could be the processes behind the nocturnal rain in the western part of China (to the west of about 110°E). Daytime precipitation in the eastern part of China (to the east of about 110°E) could be attributed to the moist convection connected with solar heating. The morning peaks for stations in the middle and lower reaches of the Yangtze River and the North China Plain and the magnitude changing pattern in the eastern part seem to be connected with the advance and retreat of the East Asian summer monsoon. The morning maxima at coastal stations may be mainly attributed to the local land–sea breeze. The seasonal changes of diurnal variations for the western part of China are relatively small, with nighttime precipitation maxima remaining fairly constant during the warm season. This part is not directly influenced by the monsoon. For most of the stations in the eastern part, morning peaks tend to be strengthened/weakened along with the East Asian monsoon's advancing/retreating. Copyright © 2008 Royal Meteorological Society
Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2003–2004
Authors: Harvey David J. 
Published: September 2008

AbstractThis review is the third update of the original review, published in 1999, on the application of matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings the topic to the end of 2004. Both fundamental studies and applications are covered. The main topics include methodological developments, matrices, fragmentation of carbohydrates and applications to large polymeric carbohydrates from plants, glycans from glycoproteins and those from various glycolipids. Other topics include the use of MALDI MS to study enzymes related to carbohydrate biosynthesis and degradation, its use in industrial processes, particularly biopharmaceuticals and its use to monitor products of chemical synthesis where glycodendrimers and carbohydrate–protein complexes are highlighted. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:273–361, 2009
Clinical and genetic characterization of a large Dutch family with primary focal dystonia
Authors: Contarino Maria Fiorella , Berger‐Plantinga Elles , Foncke Elisabeth M.J. , Ritz Katja , Mellema Jonke , Baas Frank , Speelman Johannes D. , Tijssen Marina A.J. 
Published: September 2008

AbstractWe describe a large family with a primary focal dystonia from a small Dutch village on a former island. Twenty‐four individuals spanning three generations were examined by two movement‐disorder neurologists. Two other movement‐disorder neurologists evaluated the videos independently. Subjects were classified as “affected,” “possibly affected,” or “not affected.” A diagnosis was defined if all the neurologists agreed on the definition. Eight definitely affected and four possibly affected subjects were detected. Clinical presentation consisted of mild cranio‐cervical‐brachial dystonia. Mean age at onset was 45.5 years (range, 39–56). Mean BFMDRS motor score was 4.4 (range, 1–8). Mean TWSTRS score (part I) was 11.3 (range, 8–23). Mutations in DYT1 gene and in the ε‐sarcoglycan (SGCE) genes were not detected. We could not find linkage to the dominant DYT6, DYT7, DYT13, or the recessive DYT16 loci. The identification and accurate clinical evaluation of large dystonia families not linked to known genes is crucial for further advancement in molecular genetic characterization of focal dystonia. © 2008 Movement Disorder Society
The relationships among self‐esteem, stress, coping, eating behavior, and depressive mood in adolescents
Authors: Martyn‐Nemeth Pamela , Penckofer Sue , Gulanick Meg , Velsor‐Friedrich Barbara , Bryant Fred B. 
Published: September 2008

AbstractThe prevalence of adolescent overweight is significant, almost 25% in some minorities, and often is associated with depressive symptoms. Psychological and psychosocial factors as well as poor coping skills have been correlated with unhealthy eating and obesity. The purpose of this study was to examine relationships among self‐esteem, stress, social support, and coping; and to test a model of their effects on eating behavior and depressive mood in a sample of 102 high school students (87% minority). Results indicate that (a) stress and low self‐esteem were related to avoidant coping and depressive mood, and that (b) low self‐esteem and avoidant coping were related to unhealthy eating behavior. Results suggest that teaching adolescents skills to reduce stress, build self‐esteem, and use more positive approaches to coping may prevent unhealthy eating and subsequent obesity, and lower risk of depressive symptoms. © 2008 Wiley Periodicals, Inc. Res Nurs Health 32:96–109, 2009