bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ascorbate decreases Fabry cerebral hyperperfusion suggesting a reactive oxygen species abnormality: An arterial spin tagging study
Authors: Moore David F. , Ye Frank , Brennan Marie‐Luise , Gupta Surya , Barshop Bruce A. , Steiner Robert D. , Rhead William J. , Brady Roscoe O. , Hazen Stanley L. , Schiffmann Raphael 
Published: September 2004

AbstractPurposeTo test the hypothesis that reactive oxygen species contribute to the cerebral hyperperfusion in Fabry disease.Material and MethodsWe examined the effect of intravenous injection of ascorbate on cerebral blood flow (CBF) using magnetic resonance arterial spin tagging. Nineteen patients with Fabry disease and 15 control subjects were studied as part of a randomized double‐blind placebo‐controlled trial of enzyme replacement therapy (ERT).ResultsVertebro‐basilar hyperperfusion was observed in patients with Fabry disease. A decrease in systemic ascorbate levels relative to healthy controls was found in the patients. CBF decreased after ascorbate infusion in both control subjects and patients treated with ERT. The placebo group had a significantly delayed decrease in the CBF response after ascorbate infusion. Myeloperoxidase levels were elevated in Fabry patients, consistent with ongoing inflammatory processes in these patients.ConclusionIncreased CBF in Fabry disease may be related to increased production of reactive oxygen species, while low plasma ascorbate levels suggests a global redox imbalance. These abnormalities were improved by ERT. These observations have implications regarding oxidative processes contributing to accelerated atherosclerosis in Fabry disease. J. Magn. Reson. Imaging 2004;20:674–683. Published 2004 Wiley‐Liss, Inc.
On flow effects in balanced steady‐state free precession imaging: Pictorial description, parameter dependence, and clinical implications
Authors: Markl Michael , Pelc Norbert J. 
Published: September 2004

AbstractPurposeTo present a pictorial description of the origin of flow effects in balanced steady‐state free precession (SSFP) imaging that can result in considerable frequency offset‐dependent signal changes originating from outflow of spins that can still contribute to the total SSFP signal (out‐of‐slice contributions), to analyze the parameter dependence and slice broadening associated with outflow effects, and to illustrate clinical implications such as frequency offset‐dependent flow artifacts and spatial misencoding.Materials and MethodsComputer simulations were used to create a pictorial description of flow effects that illustrates the origin and parameter dependence of the observed signal changes and links their frequency dependency to the phase distribution of spins flowing in and out of the imaging slice. Slice broadening associated with out‐of‐slice contributions and flow‐related signal enhancement was characterized by an effective slice thickness, which depends on flow rate, the T2* decay of signal magnitude from spins that have left the imaging slice, and the ratio of the net out‐of‐slice magnetization relative to the thickness of the imaging slice.ResultsBoth simulated SSFP signal intensities and effective slice broadening vary with flip angle and demonstrate a nonlinear dependence on inflow. Simulations with bloodlike T1 and T2 show that the effective slice thickness can be as large as 15 times the prescribed slice thickness. These effects can have significant clinical implications such as large frequency offset‐dependent signal enhancement, pulsatile flow artifacts, and spatial misrepresentation of blood signal that has already left the imaging slice.ConclusionFlow‐related signal changes in SSFP imaging exhibit highly complex parameter dependence, which predominantly has to be associated with frequency offset‐dependent outflow effects and a resulting broadening of the slice thickness. J. Magn. Reson. Imaging 2004;20:697–705. © 2004 Wiley‐Liss, Inc.
The influence of myocardial blood flow and volume of distribution on late Gd‐DTPA kinetics in ischemic heart failure
Authors: Klein Christoph , Nekolla Stephan G. , Balbach Thomas , Schnackenburg Bernhard , Nagel Eike , Fleck Eckart , Schwaiger Markus 
Published: September 2004

AbstractPurposeTo determine the mechanism of enhancement of contrast‐enhanced MRI (ceMRI) in chronic ischemic myocardium. While ceMRI can identify scar tissue in chronic ischemic myocardium, the mechanism of enhancement is not completely understood.Materials and MethodsA total of 11 patients with ischemic heart failure (ejection fraction [EF] 28 ± 9%) were imaged with ceMRI and positron emission tomography (PET) to measure myocardial blood flow (MBF). Longitudinal relaxation rate (T1) of blood, normal tissue, and scar tissue defined by ceMRI was determined before and two to 50 minutes after contrast (Look Locker technique), and the partition coefficient (λ) and volume of distribution (VD) were calculated.ResultsIn scar and viable tissue, T1 was significantly different over the whole period after contrast, but not before contrast. However, T1 of scar and blood were similar five to 15 minutes post contrast, making the detection of subendocardial defects difficult. λ reached an initial steady state in viable tissue, but was delayed (20 minutes) in scar tissue. VD in scar was double that of viable tissue (0.54 ± 0.01 vs. 0.29 ± 0.02, respectively) indicating an increased interstitial space. Contrast wash‐in kinetics correlated moderately with MBF (r = –0.36), but well with the combination of MBF and VD (r = 0.59).ConclusionLate myocardial contrast kinetics depend on both MBF and VD; however the increased VD seems to be the main mechanism for the late enhancement effect. J. Magn. Reson. Imaging 2004;20:588–594. © 2004 Wiley‐Liss, Inc.
Comparison of dynamic gadolinium‐enhanced and ferumoxides‐enhanced MRI of the liver on high‐ and low‐field scanners
Authors: Limanond Piyaporn , Raman Steven S. , Sayre James , Lu David S.K. 
Published: September 2004

AbstractPurposeTo compare the performance of dynamic gadolinium‐enhanced and ferumoxides‐enhanced MRI in the detection and characterization of hepatic lesions, on 1.5‐T and 0.2‐T magnetsMaterials and MethodsIn 41 patients (23 men, 18 women), 52 hepatic MR examinations were performed and retrospectively analyzed; 39 and 13 examinations were performed on 1.5‐T and 0.2‐T magnets, respectively. A total of 33 of 41 patients had known malignancies, and 31 of 33 patients had biopsy of at least one lesion. First, a combination of unenhanced T2‐weighted sequences and gradient‐echo T1‐weighted sequences were performed. Then, dynamic gadolinium‐enhanced (0.1 mmol/kg) T1 GRE sequences were obtained, followed by intravenous drip infusion of ferumoxides (10 μmol/kg). The T2‐weighted sequences were then repeated. The unenhanced and gadolinium‐enhanced images (the Gd set) were reviewed separately from the unenhanced and ferumoxides‐enhanced images (the ferumoxides set) by two abdominal imagers. The reviewers were blinded to clinical history and reviewed the individual studies in each set randomly. Each detected lesion was scored on a five‐point scale for characterization scores: nonsolid (1 or 2), indeterminate (3), or solid (4 or 5). A consensus review was then performed correlating all available pathology, imaging, clinical findings, and follow‐up to act as a gold standard. Receiver‐operating‐characteristic (ROC) curves were generated and both area‐under‐the‐curve (Az values) and sensitivity values were calculated. Significance of Az and sensitivity differences was assessed using standard Z‐test and chi‐square.ResultsOf 270 lesions detected by consensus, 211 were on 1.5‐T and 59 were on 0.2‐T scanners. The accuracy (Az values) of lesion detection overall, of both readers, was greater for the ferumoxides set than for the Gd set (reader 1: 0.95 vs. 0.89 (P < 0.05); reader 2: 0.91 vs. 0.78 (P < 0.05)). Az values for both readers were greater on the ferumoxides set for both the 1.5‐T scans and the 0.2‐T scans. Out of 270 lesions detected, 231 were characterized by consensus review as solid (185) or nonsolid (46). There was a significant improvement in lesion characterization for both readers on the GD set compared with the ferumoxides set on both high and low field scanners (Az reader 1: 0.99 vs. 0.96 (P < 0.05); Az reader 2: 0.99 vs. 0.95 (P < 0.05)), respectively.ConclusionAt both 1.5‐T and 0.2‐T, ferumoxides‐enhanced sequences were better for lesion detection, while gadolinium‐enhanced sequences were better for lesion characterization, respectively. J. Magn. Reson. Imaging 2004;20:640–647. © 2004 Wiley‐Liss, Inc.
Dose optimization of mannitol solution for small bowel distension in MRI
Authors: Ajaj Waleed , Goehde Susanne C. , Schneemann Hubert , Ruehm Stefan G. , Debatin Jörg F. , Lauenstein Thomas C. 
Published: September 2004

AbstractPurposeTo optimize the dose of a hydro solution containing 2.5% mannitol and 0.2% locust bean gum (LBG) for small bowel MRI in terms of bowel distension and patient acceptance.Materials and MethodsA total of 10 healthy volunteers ingested a hydro solution containing 2.5% mannitol and 0.2% LBG. Four different volumes (1500, 1200, 1000, and 800 ml) were assessed on four different examination days. Small bowel distension was quantified on coronal two‐dimensional TrueFISP images by measuring the diameter of eight bowel loops throughout the jejunum and the ileum. In addition, volunteer acceptance was evaluated for every single examination by using a questionnaire.ResultsOptimal distension was obtained with either, 1000, 1200, or 1500 ml, with no statistically significant differences in distension between these groups. Administration of 800 ml led to significantly less distension of the small bowel. Significantly less side effects were noted using either 800 or 1000 ml compared to using larger volumes.ConclusionWe recommend a dose of 1000 ml mannitol/LBG solution as an oral contrast agent for optimal bowel distension and minimal side effects. J. Magn. Reson. Imaging 2004;20:648–653. © 2004 Wiley‐Liss, Inc.
An accurate and robust method for unsupervised assessment of abdominal fat by MRI
Authors: Positano Vincenzo , Gastaldelli Amalia , Sironi Anna maria , Santarelli Maria Filomena , Lombardi Massimo , Landini Luigi 
Published: September 2004

AbstractPurposeTo describe and evaluate an automatic and unsupervised method for assessing the quantity and distribution of abdominal adipose tissue by MRI.Material and MethodsA total of 20 patients underwent whole‐abdomen MRI. A total of 32 transverse T1‐weighted images were acquired from each subject. The data collected were transferred to a dedicated workstation and analyzed by both our unsupervised method and a manual procedure. The proposed methodology allows the automatic processing of MRI axial images, segmenting the adipose tissue by fuzzy clustering approach. The use of an active contour algorithm on image masks provided by the fuzzy clustering algorithm allows the separation of subcutaneous fat from visceral fat. Finally, an automated procedure based on automatic image histogram analysis identifies the visceral fat.ResultsThe accuracy, reproducibility, and speed of our automatic method were compared with the state‐of‐the‐art manual approach. The unsupervised analysis correlated well with the manual analysis, and was significantly faster than manual tracing. Moreover, the unsupervised method was not affected by intraobserver and interobserver variability.ConclusionThe results obtained demonstrate that the proposed method can provide the volume of subcutaneous adipose tissue, visceral adipose tissue, global adipose tissue, and the ratio between subcutaneous and visceral fat in an unsupervised and effective manner. J. Magn. Reson. Imaging 2004;20:684–689. © 2004 Wiley‐Liss, Inc.
Diffusion tensor eigenvector directional color imaging patterns in the evaluation of cerebral white matter tracts altered by tumor
Authors: Field Aaron S. , Alexander Andrew L. , Wu Yu‐Chien , Hasan Khader M. , Witwer Brian , Badie Behnam 
Published: September 2004

AbstractPurposeTo categorize the varied appearances of tumor‐altered white matter (WM) tracts on diffusion tensor eigenvector directional color maps.Materials and MethodsDiffusion tensor imaging (DTI) was obtained preoperatively in 13 patients with brain tumors ranging from benign to high‐grade malignant, including primary and metastatic lesions, and maps of apparent diffusion coefficient (ADC), fractional anisotropy (FA), and major eigenvector direction were generated. Regions of interest (ROIs) were drawn within identifiable WM tracts affected by tumor, avoiding grossly cystic and necrotic regions, known fiber crossings, and gray matter. Patterns of WM tract alteration were categorized on the basis of qualitative analysis of directional color maps and correlation analysis of ADC and FA.ResultsFour basic patterns of WM alteration were identified: 1) normal or nearly normal FA and ADC, with abnormal tract location or tensor directions attributable to bulk mass displacement, 2) moderately decreased FA and increased ADC with normal tract locations and tensor directions, 3) moderately decreased FA and increased ADC with abnormal tensor directions, and 4) near isotropy. FA and ADC were inversely correlated for Patterns 1–3 but did not discriminate edema from infiltrating tumor. However, in the absence of mass displacement, infiltrating tumor was found to produce tensor directional changes that were not observed with vasogenic edema, suggesting the possibility of discrimination on the basis of directional statistics.ConclusionTumor alteration of WM tracts tends to produce one of four patterns on FA and directional color maps. Clinical application of these patterns must await further study. J. Magn. Reson. Imaging 2004;20:555–562. © 2004 Wiley‐Liss, Inc.
In vivo 4.0‐T magnetic resonance investigation of spinal cord inflammation, demyelination, and axonal damage in chronic‐progressive experimental allergic encephalomyelitis
Authors: Cook Lisa L. , Foster Paula J. , Mitchell J. Ross , Karlik Stephen J. 
Published: September 2004

AbstractPurposeTo image and dissect the lumbar spinal cord of guinea pigs with chronic‐progressive experimental allergic encephalomyelitis (CP‐EAE) and directly correlate the pathology to the magnetic resonance (MR) image data obtained at 4 T and determine if these MR contrasts can accurately differentiate a specific type of pathology from control tissue.Materials and MethodsThe amount of inflammation, demyelination, and axonal pathology were quantified in the whole cord cross sections. The signal intensities (SIs) for 228 individual regions of interest (ROIs) (normal‐appearing white matter (NAWM) and tissue containing inflammation with or without demyelination) were measured directly from the corresponding area on the MR images.ResultsConventional MR contrast SIs and magnetization transfer ratio (MTR) were related to the degree of demyelination and presence of inflammation. MTR and proton density‐weighted (PDw) SIs were both moderately related to axonal density. The SIs for NAWM and in lesions containing both cellular infiltrates and demyelination in all conventional MR contrast images were also increased, whereas the MTR was decreased when compared to control tissue.ConclusionThe SIs from the conventional MR contrasts and MTR at 4 T were sensitive to the presence of disease within CP‐EAE spinal cord, but were not specific to the underlying pathology. J. Magn. Reson. Imaging 2004;20:563–571. © 2004 Wiley‐Liss, Inc.
Delayed hyper‐enhancement of myocardium in hypertrophic cardiomyopathy with asymmetrical septal hypertrophy: Comparison with global and regional cardiac MR imaging appearances
Authors: Amano Yasuo , Takayama Morimasa , Takahama Katsuya , Kumazaki Tatuso 
Published: September 2004

AbstractPurposeTo evaluate the relationship between delayed hyper‐enhancement of the myocardium and global and regional cardiac abnormalities in hypertrophic cardiomyopathy (HCM) with asymmetrical septal hypertrophy using magnetic resonance (MR) imaging.Materials and MethodsTwenty‐three patients with HCM with asymmetrical septal hypertrophy were examined using a 1.5‐T MR unit. Contrast‐enhanced inversion‐recovery gradient‐echo imaging was performed to observe the myocardial damages associated with HCM. Balanced steady‐state free precession imaging was performed to assess regional wall abnormalities and ejection fraction, and black‐blood fast spin‐echo imaging was performed to assess left atrial diameter.ResultsDelayed hyper‐enhancement of the myocardium was primarily observed in the interventricular septal wall. Septal walls with the higher transmural extent of delayed hyper‐enhancement were significantly thicker at end‐diastole and end‐systole (P < 0.05), and tended to show a decreased percentage systolic wall thickening (P = 0.079). There were no differences in theses values between non‐enhancing septal walls and septal walls with the transmural extent < 50%.ConclusionThe high transmural extent of delayed hyper‐enhancement of the myocardium may reflect the severe myocardial damage associated with the regional hypertrophy and hypokinesia in HCM. J. Magn. Reson. Imaging 2004;20:595–600. © 2004 Wiley‐Liss, Inc.
Long‐term imaging effects in rat liver after a single injection of an iron oxide nanoparticle based MR contrast agent
Authors: Briley‐Sæbø Karen , Hustvedt Svein‐Olaf , Haldorsen Anita , Bjørnerud Atle 
Published: September 2004

AbstractPurposeTo investigate the duration of liver R2* enhancement and pharmacokinetics following administration of an iron oxide nanoparticle in a rat model.Materials and MethodsRats were injected with 0, 1, 2, or 5 mg Fe/kg of NC100150 Injection, and quantitative in vivo 1/T2* liver measurements were obtained between 1 and 133 days after injection. The concentration of NC100150 Injection was determined by relaxometry methods in ex vivo rat liver homogenate.ResultsAt all dose levels, 1/T2* remained greater than control values up to 63 days after injection. In the highest dose group, 1/T2* was above control levels during the entire 133 day time‐course investigated. There were no quantifiable amounts of NC100150 Injection present 63 days after injection in any of the dose groups. The half‐life of NC100150 Injection in rat liver was dose dependent. For the lowest dose group, the degradation of the particles could be defined by a mono‐exponential function with a half‐life of eight days. For the 2 and 5 mg Fe/kg dose groups, the degradation was bi‐exponential with a fast initial decay of seven to eight days followed by a slow terminal decay of 43–46 days.ConclusionNC100150 Injection exhibits prolonged 1/T2* enhancement in rat liver. The liver enhancement persisted at time points when the concentration of iron oxide particles present in the liver was below method detection limits. The prolonged 1/T2* enhancement is likely a result of the particle breakdown products and the induction of ferritin and hemosiderin with increasing iron cores/loading factors. J. Magn. Reson. Imaging 2004;20:622–631. © 2004 Wiley‐Liss, Inc.
Efficacy of 904 nm gallium arsenide low level laser therapy in the management of chronic myofascial pain in the neck: A double‐blind and randomize‐controlled trial
Authors: Gur Ali , Sarac Aysegul Jale , Cevik Remzi , Altindag Ozlem , Sarac Serdar 
Published: September 2004

AbstractBackground and ObjectivesA prospective, double‐blind, randomized, and controlled trial was conducted in patients with chronic myofascial pain syndrome (MPS) in the neck to evaluate the effects of infrared low level 904 nm Gallium‐Arsenide (Ga‐As) laser therapy (LLLT) on clinical and quality of life (QoL).Study Design/Patients and MethodsThe study group consisted of 60 MPS patients. Patients were randomly assigned to two treatment groups: Group I (actual laser; 30 patients) and Group II (placebo laser; 30 patients). LLLT continued daily for 2 weeks except weekends. Follow‐up measures were evaluated at baseline, 2, 3, and 12 weeks. All patients were evaluated with respect to pain at rest, pain at movement, number of trigger points (TP), the Neck Pain and Disability Visual Analog Scale (NPAD), Beck depression Inventory (BDI), and the Nottingham Health Profile (NHP).ResultsIn active laser group, statistically significant improvements were detected in all outcome measures compared with baseline (P < 0.01) while in the placebo laser group, significant improvements were detected in only pain score at rest at the 1 week later of the end of treatment. The score for self‐assessed improvement of pain was significantly different between the active and placebo laser groups (63 vs. 19%) (P < 0.01).ConclusionThis study revealed that short‐period application of LLLT is effective in pain relief and in the improvement of functional ability and QoL in patients with MPS. Lasers Surg. Med. 35:229–235, 2004. © 2004 Wiley‐Liss, Inc.
Laser and novel light source treatments for psoriasis
Authors: Tournas Joshua A. , Lowe Nicholas J. , Yamauchi Paul S. 
Published: September 2004

AbstractBackground and ObjectivesThere are many treatment modalities for psoriasis including topical therapy, ultraviolet light therapy, systemic agents, and more recently the advent of the biologic agents.Study Design/Materials and MethodsIn addition, selective treatment using lasers and light sources that target the individual psoriatic plaques have also been employed.Results/ConclusionThis article will highlight and review the employment of laser‐assisted devices in the treatment of plaque psoriasis. Lasers Surg. Med. 35:165–173, 2004. © 2004 Wiley‐Liss, Inc.
Comparison of red and green laser doppler imaging of blood flow
Authors: Murray Andrea K. , Gorodkin Rachel E. , Moore Tonia L. , Gush Rodney J. , Herrick Ariane L. , King Terence A. 
Published: September 2004

AbstractBackground and ObjectivesLaser Doppler imaging (LDI) of perfusion has been performed with a novel green wavelength (532 nm) for comparison with a HeNe laser (633 nm), the aim being validation of the green laser wavelength as a research tool.Study Design/Materials and MethodsThe effect of wavelength and power on images was investigated and perfusion response following both finger occlusion and local heating of the dorsum were examined as reproducible stimuli for clinical studies.ResultsThe most striking difference between red and green LDI is the absence of veins on green LDI, which are seen with red LDI. Differences have been quantified using vein LDI profiles. Differences were found between blood flow responses imaged by red and green LDI (3 and 5 mW, respectively) for occlusion and heat stimuli. Results are discussed in the context of light penetration.ConclusionsRed and green wavelengths appear to image different components of the microcirculation. Lasers Surg. Med. 35:191–200, 2004. © 2004 Wiley‐Liss, Inc.