bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of multicoil breast arrays for parallel imaging
Authors: Marshall Helen , Devine Patrick M. , Shanmugaratnam Nishanthan , Fobel Ryan , Siegler Peter , Piron Cameron A. , Plewes Donald B. 
Published: January 2010

AbstractPurpose:To evaluate three multicoil breast arrays for both conventional and SENSE‐accelerated imaging.Materials and Methods:Two commercially available 8‐element coils and a prototype 16‐element coil were compared. One 8‐element array had adjustable coils located next to the breast tissue and the other had a fixed coil arrangement; both were designed to allow parallel imaging in the left–right direction. The 16‐element coil was designed to have coil sensitivity variation in both the left–right and superior–inferior directions, and also had adjustable coils. Their performance was assessed in terms of signal‐to‐noise ratio (SNR), g‐factor, and uniformity with a custom‐built phantom.Results:The 16‐element array with adjustable coils provided the highest SNR, while the 8‐element coil with a fixed coil arrangement had the best uniformity. All coils performed well for SENSE acceleration in the left–right direction. The 8‐element coils did not have the capability for acceleration in the superior–inferior direction across the whole volume. The 16‐element coil enabled acceleration in the superior–inferior direction in addition to the left–right direction.Conclusion:Smaller, adjustable coil elements located next to breast tissue can provide greater SNR than larger, fixed coil elements. A multicoil breast array with high intrinsic SNR and low g‐factors enables high‐quality parallel imaging. J. Magn. Reson. Imaging 2010; 31: 328–338. © 2010 Wiley‐Liss, Inc.
Decreased incidence of NSF in patients on dialysis after changing gadolinium contrast‐enhanced MRI protocols
Authors: Martin Diego R. , Krishnamoorthy Saravanan K. , Kalb Bobby , Salman Khalil N. , Sharma Puneet , Carew John D. , Martin Phillip A. , Chapman Arlene B. , Ray Gaye L. , Larsen Christian P. , Pearson Thomas C. 
Published: January 2010

AbstractPurpose:To retrospectively determine the incidence of nephrogenic systemic fibrosis (NSF) in patients on dialysis administered either a lower dose high‐relaxivity linear gadolinium‐chelate, gadobenate dimeglumine (MultiHance, MH), compared to a standard dose linear gadolinium chelate, gadodiamide (Omniscan, OM).Materials and Methods:This study was Health Insurance Portability and Accountability Act (HIPAA)‐compliant and Institutional Review Board (IRB)‐approved. As per institution standardized contrast‐enhanced magnetic resonance imaging (MRI) protocols, patients on dialysis were imaged using either MH, between 2/2007 to 9/2008, or OM between 10/2003 and 1/2007. Rates of NSF were compared using 95% score‐based confidence intervals (CI). The Wilcoxon rank sum test was used to test similarity/difference between contrast doses given to each patient group.Results:Overall, 312 patients on dialysis received OM and eight (2.6%) developed NSF (95% CI: 1.30%–4.98%). In all, 784 patients on dialysis received MH at a mean cumulative dose of 0.11 mmol/kg (0.05–0.75 mmol/kg) and no cases of NSF were identified (upper 95% confidence bound of 0.45%). The mean cumulative dose of OM was 0.16 mmol/kg (0.1–0.9 mmol/kg) for all patients and 0.28 mmol/kg (0.1–0.8 mmol/kg) for the patients with NSF. The median OM dose was greater in patients who developed NSF (P = 0.03), and was greater than the median MH dose (P < 0.005).Conclusion:NSF incidence in at‐risk patients receiving contrast‐enhanced MRI can be reduced after changing contrast administration protocols that includes changing the type and dose of contrast agent. J. Magn. Reson. Imaging 2010; 31: 440–446. © 2010 Wiley‐Liss, Inc.
High resolution noncontrast MRI of the hip
Authors: Potter Hollis G. , Schachar Jennifer 
Published: January 2010

AbstractThe relatively thin cartilage of the hip joint, as well as its complex geometry, poses challenges for standardized, reproducible assessment of cartilage and the acetabular labrum. With appropriate pulse sequence parameters, however, accurate, reproducible assessment of cartilage and the labrum is feasible. More detailed evaluation of cartilage biochemistry may be obtained with techniques aimed at noninvasively evaluating the integrity of collagen and/or proteoglycan components in the articular cartilage. One of the benefits of noncontrast techniques lie in the ability to visualize the native synovium, and thereby detect the presence of synovial proliferative disorders, the clinical symptoms of which may mimic a labral tear or traumatic cartilage injury. Standard cartilage evaluation allows for the detection of surface delamination and osteoarthritis in the setting of femoroacetabular impingement, as well as subtle areas of subchondral collapse and secondary delamination of cartilage in the setting of osteonecrosis. This preserves the use of hip arthroscopy as a therapeutic rather than a diagnostic tool. J. Magn. Reson. Imaging 2010; 31: 268–278. ©2010 Wiley‐Liss, Inc.
Measuring perfusion and permeability in renal cell carcinoma with dynamic contrast‐enhanced MRI: A pilot study
Authors: Notohamiprodjo Mike , Sourbron Steven , Staehler Michael , Michaely Henrik J. , Attenberger Ulrike I. , Schmidt Gerwin P. , Boehm Holger , Horng Annie , Glaser Christian , Stief Christian , Reiser Maximilian F. , Herrmann Karin A. 
Published: January 2010

AbstractPurpose:To retrospectively assess an improved quantitative methodology with separate assessment of perfusion and permeability for characterization of primary renal cell carcinoma (RCC) and monitoring antiangiogenic treatment.Materials and Methods:Fifteen RCC patients before surgery, 6 RCC patients before and after neoadjuvant antiangiogenic therapy, and 15 patients without renal disease underwent dynamic contrast‐enhanced (DCE)‐MRI of the kidney with integrated retrospective respiratory triggering and an individual arterial input function. Tracer kinetic analysis was performed with a two‐compartment‐filtration‐model for the kidney data and a two‐compartment‐exchange‐model for the tumor data, providing four independent parameters: the perfusion‐parameters plasma flow (FP) and plasma volume (VP), and the permeability‐parameters extraction flow (FE) and extravascular‐extracellular volume (VE).Results:In tumors FP and FE were significantly lower than in normal kidneys. Tracer kinetic analysis displayed hemodynamic alteration caused by vessel infiltration or necrosis. Papillary RCC could be differentiated from clear‐cell variants by a distinct perfusion pattern. In antiangiogenically treated RCC VE was not significantly decreased, while the perfusion parameters VP and FP were significantly diminished.Conclusion:DCE‐MRI with integrated motion compensation enables evaluation of primary RCC and detects distinct perfusion patterns. Quantification with a two‐compartment‐exchange‐model produces a separate perfusion‐ and permeability characterization and may become a diagnostic tool to monitor antiangiogenic treatment. J. Magn. Reson. Imaging 2010; 31: 490–501. © 2010 Wiley‐Liss, Inc.
Measurement of brain iron distribution in Hallevorden‐Spatz syndrome
Authors: Szumowski Jerzy , Bas Erhan , Gaarder Kirsten , Schwarz Erwin , Erdogmus Deniz , Hayflick Susan 
Published: January 2010

AbstractPurpose:To investigate spatial distribution of iron accumulation in the globus pallidus (GP) in patients with Hallevorden‐Spatz syndrome (HSS) using phase imaging. We compared sensitivity of a phase imaging technique to relaxation rate measurement methods (R1,R2,R2*) for iron quantification.Materials and Methods:R1, R2, and R2* were measured in GP structure of the brain of eight pantothenate kinase‐associated neurodegeneration (PKAN) patients and a healthy volunteer using a 3T magnetic resonance imaging (MRI) scanner. The phase of gradient‐echo images was preprocessed to eliminate phase 2π wrapping and filtered to remove phase background variations. Phase gap across GP structure was used as a metric for iron effects quantification.Results:Among the relaxation rates the most sensitive to iron accumulation was the R2* rate. The R1 and R2 rates demonstrated only small variations in this group of subjects. Up to an order of magnitude phase gap changes were measured between one PKAN patient and an age‐matched healthy volunteer. Assuming that phase gap differences scale linearly with iron concentration we estimate that up to 2 mg Fe/g ww accumulates in GP of these patients.Conclusion:Our results demonstrate significantly higher sensitivity of the phase measurements for quantitative assessment of iron concentration compared to the relaxation rate measurements. Phase measurements could potentially be used for monitoring a progression and a response to therapy in PKAN. J. Magn. Reson. Imaging 2010; 31: 482–489. © 2010 Wiley‐Liss, Inc.
Comparison of gadodiamide‐enhanced MR angiography to intraarterial digital subtraction angiography for evaluation of renal artery stenosis: Results of a phase III multicenter trial
Authors: Garovic Vesna D. , Achauer Manuela A. , Kittner Thomas , Horák David , Sheng Rubin , Stanson Anthony W. 
Published: January 2010

AbstractPurpose:To evaluate the efficacy and safety of 0.1 mmol/kg gadodiamide administration for contrast‐enhanced magnetic resonance angiography (MRA) in detecting hemodynamically relevant renal artery stenosis (RAS) when compared with intraarterial digital subtraction angiography (IA‐DSA) as the gold standard.Materials and Methods:In a multicenter, controlled study, 395 patients with suspected or known RAS were included. Three independent readers evaluated the MRA images. Two readers evaluated the IA‐DSA images and subsequently achieved consensus. The sensitivities and specificities of gadodiamide‐enhanced MRA were analyzed at the per‐patient and per‐vessel levels (exact 1‐sided binomial test at α = 0.025 with 95% confidence interval).Results:A total of 335 patients who had available standard of truth and MRA tests were included in the all‐subjects efficacy population: 55.5% (186/335) men and 44.5% women with a mean age of 63 ± 13 years (range 17–85 years). The sensitivities and specificities ranged from 81% to 86% for all independent readers at the per‐patient analysis based on subjects with the diagnostic images. Similar results were achieved with per‐vessel level analysis. Fewer than 1% of patients had adverse event associated with gadodiamide administration. There were no cases of nephrogenic systemic fibrosis (NSF) reported.Conclusion:Gadodiamide administration at the labeled dose of 0.1 mmol/kg for contrast‐enhanced MRA achieved equivalent results compared to IA‐DSA in evaluation of RAS and was well tolerated. J. Magn. Reson. Imaging 2010; 31: 390–397. © 2010 Wiley‐Liss, Inc.
Quantification of 3D regional myocardial wall thickening from gated magnetic resonance images
Authors: Prasad Mithun , Ramesh Amit , Kavanagh Paul , Tamarappoo Balaji K. , Nakazato Ryo , Gerlach James , Cheng Victor , Thomson Louise E.J. , Berman Daniel S. , Germano Guido , Slomka Piotr J. 
Published: January 2010

AbstractPurpose:To develop 3D quantitative measures of regional myocardial wall motion and thickening using cardiac magnetic resonance imaging (MRI) and to validate them by comparison to standard visual scoring assessment.Materials and Methods:In all, 53 consecutive subjects with short‐axis slices and mid‐ventricular 2‐chamber/4‐chamber views were analyzed. After correction for breath‐hold‐related misregistration, 3D myocardial boundaries were fitted to images and edited by an imaging cardiologist. Myocardial thickness was quantified at end‐diastole and end‐systole by computing the 3D distances using Laplace's equation. 3D thickening was represented using the standard 17‐segment polar coordinates. 3D thickening was compared with 3D wall motion and with expert visual scores (6‐point visual scoring of wall motion and wall thickening; 0 = normal; 5 = greatest abnormality) assigned by imaging cardiologists.Results:Correlation between ejection fraction and thickening measurements was (r = 0.84; P < 0.001) compared to correlation between ejection fraction and motion measurements (r = 0.86; P < 0.001). Good negative correlation between summed visual scores and global wall thickening and motion measurements were also obtained (rthick = −0.79; rmotion = −0.74). Additionally, overall good correlation between individual segmental visual scores with thickening/wall motion (rthick = −0.69; rmotion = −0.65) was observed (P < 0.0001).Conclusion:3D quantitative regional thickening and wall motion measures obtained from MRI correlate strongly with expert clinical scoring. J. Magn. Reson. Imaging 2010; 31: 317–327. © 2010 Wiley‐Liss, Inc.
PC HYPR flow: A technique for rapid imaging of contrast dynamics
Authors: Velikina Julia V. , Johnson Kevin M. , Wu Yijing , Samsonov Alexey A. , Turski Patrick , Mistretta Charles A. 
Published: January 2010

AbstractPurpose:To improve spatial and temporal resolution and signal‐to‐noise ratio (SNR) in three‐dimensional (3D) radial contrast‐enhanced (CE) time‐resolved MR angiography by means of a novel hybrid phase contrast (PC) and CE MRA acquisition and HYPR reconstruction (PC HYPR Flow).Materials and Methods:PC HYPR Flow consists of a CE exam immediately followed by a PC scan used to constrain the HYPR reconstruction of the time series. Temporal resolution of the new method was studied in computer simulations. The feasibility of the new technique was studied in healthy subjects and patients with brain arteriovenous malformations and in a canine model of aneurysms.Results:Simulations demonstrated preservation of contrast agent dynamics in proximal vessels, showing better performance than peer methods for acceleration up to 20 in 2D. In vivo, PC HYPR Flow yielded 3D time series with frame rate of 0.5 s and significantly outperformed two peer methods by means of a major increase in spatial resolution (0.8 × 0.8 × 0.8 mm3) and arterial/venous ratio, while maintaining necessary temporal waveform fidelity and high SNR.Conclusion:This initial study indicates that PC HYPR Flow simultaneously provides 3D isotropic sub‐millimeter spatial resolution, sub‐second temporal reconstruction windows and high SNR level, which may benefit a wide range of CE MRA applications. J. Magn. Reson. Imaging 2010; 31: 447–456. © 2010 Wiley‐Liss, Inc.
Topography mapping of whole body adipose tissue using A fully automated and standardized procedure
Authors: Würslin Christian , Machann Jürgen , Rempp Hansjörg , Claussen Claus , Yang Bin , Schick Fritz 
Published: January 2010

AbstractPurpose:To obtain quantitative measures of human body fat compartments from whole body MR datasets for the risk estimation in subjects prone to metabolic diseases without the need of any user interaction or expert knowledge.Materials and Methods:Sets of axial T1‐weighted spin‐echo images of the whole body were acquired. The images were segmented using a modified fuzzy c‐means algorithm. A separation of the body into anatomic regions along the body axis was performed to define regions with visceral adipose tissue present, and to standardize the results. In abdominal image slices, the adipose tissue compartments were divided into subcutaneous and visceral compartments using an extended snake algorithm. The slice‐wise areas of different tissues were plotted along the slice position to obtain topographic fat tissue distributions.Results:Results from automatic segmentation were compared with manual segmentation. Relatively low mean deviations were obtained for the class of total tissue (4.48%) and visceral adipose tissue (3.26%). The deviation of total adipose tissue was slightly higher (8.71%).Conclusion:The proposed algorithm enables the reliable and completely automatic creation of adipose tissue distribution profiles of the whole body from multislice MR datasets, reducing whole examination and analysis time to less than half an hour. J. Magn. Reson. Imaging 2010; 31: 430–439. © 2010 Wiley‐Liss, Inc.
3 tesla MRI of patients with a vagus nerve stimulator: Initial experience using a T/R head coil under controlled conditions
Authors: Gorny Krzysztof R. , Bernstein Matt A. , Watson Robert E. 
Published: January 2010

AbstractPurpose:To assess safety of clinical MRI of the head in patients with implanted model 100, 102, and 103 vagus nerve stimulation (VNS) Therapy Systems (Cyberonics, Inc., Houston, TX) in 3.0 Tesla MRI (GE Healthcare, Milwaukee, WI).Materials and Methods:The distributions of the radiofrequencyB1+‐field produced by the clinically used transmit/receive (T/R) head coil (Advanced Imaging Research Incorporated, Cleveland, OH) and body coil were measured in a head and shoulders phantom. These measurements were supplemented by temperature measurements on the lead tips and the implantable pulse generator (IPG) of the VNS devices in a head and torso phantom with the same two coils. Clinical 3T MRI head scans were then acquired under highly controlled conditions in a series of 17 patients implanted with VNS.Results:Phantom studies showed only weakB1+fields at the location of the VNS IPG and leads for MRI scans using the T/R head coil. The MRI‐related heating on a VNS scanned in vitro at 3T was also found to be minimal (0.4–0.8°C at the leads, negligible at the IPG). The patient MRI examinations were completed successfully without any adverse incidents. No patient reported any heating, discomfort, or any other unusual sensation.Conclusion:Safe clinical MRI head scanning of patients with implanted VNS is shown to be feasible on a GE Signa Excite 3T MRI system using one specific T/R head coil. These results apply to this particular MRI system configuration. Extrapolation or generalization of these results to more general or less controlled imaging situations without supporting data of safety is highly discouraged. J. Magn. Reson. Imaging 2010; 31: 475–481. © 2010 Wiley‐Liss, Inc.
Hepatocellular carcinoma: Assessment of response to transarterial chemoembolization with image subtraction
Authors: Kim Sooah , Mannelli Lorenzo , Hajdu Cristina H. , Babb James S. , Clark Timothy W.I. , Hecht Elizabeth M. , Taouli Bachir 
Published: January 2010

AbstractPurpose:To assess the diagnostic accuracy of image subtraction compared with nonsubtracted images obtained with contrast‐enhanced T1‐weighted imaging (CE T1WI) for the diagnosis of hepatocellular carcinoma (HCC) necrosis after transarterial chemoembolization (TACE), using liver explant as the reference standard.Materials and Methods:Thirty‐four patients who underwent TACE within 90 days of liver transplantation and CE MRI scans were assessed by two independent observers who determined the percentage of tumor necrosis using nonsubtracted and subtracted postcontrast phases. Histopathologic percentage of necrosis was retrospectively determined by an experienced pathologist. Spearman rank correlation test was used to correlate the percentages of necrosis from MR evaluation and from pathology. Receiver operating characteristics curve analysis was performed to determine the performance of subtracted versus nonsubtracted datasets for the diagnosis of complete tumor necrosis.Results:There were 57 HCCs (mean size, 2.4 cm; range, 1.2–4.2 cm) diagnosed at explant and identified on MRI, including 16 completely necrotic HCCs. Subtraction demonstrated better interobserver agreement than nonsubtraction dataset for the diagnosis of tumor necrosis. There was a strong correlation between image subtraction and histopathologic assessment of necrosis (r = 0.80–0.86, depending on the phase, P < 0.0001). Subtraction demonstrated significantly higher sensitivity and accuracy for the diagnosis of complete tumor necrosis compared with nonsubtracted dataset.Conclusion:Image subtraction enables accurate assessment of necrosis of HCC after TACE with the best accuracy observed at the arterial phase. J. Magn. Reson. Imaging 2010; 31: 348–355. © 2010 Wiley‐Liss, Inc.
Correlations between in vivo 1H MRS and ex vivo 1H HRMAS metabolite measurements in adult human gliomas
Authors: Opstad Kirstie S. , Wright Alan J. , Bell B. Anthony , Griffiths John R. , Howe Franklyn A. 
Published: January 2010

AbstractPurpose:To assess how accurately ex vivo high‐resolution magic angle spinning (HRMAS) proton magnetic resonance spectroscopy (1H MRS) from small biopsy tissues relate to in vivo 1H MRS (from larger tumor volumes) in human astrocytomas.Materials and Methods:In vivo (PRESS, TE = 30 msec) and ex vivo (presaturation) 1H spectra of 17 human astrocytomas (4 grade II, 1 grade III and 12 glioblastomas) were quantified using LCModel. Concentrations of 11 metabolites and 2 lipid/macromolecules were retrospectively compared, with histogram analysis of the in vivo MRI data used to evaluate tumor heterogeneity.Results:For homogeneous‐appearing tumors, significant correlations were found between in vivo and ex vivo 1H MRS concentrations of those metabolites known to be metabolically stable in postmortem tissues (eg, creatine, myo‐inositol, total cholines, and the ≈1.3 and 0.9 ppm lipids). Anaerobic glycolysis during biopsy surgical removal depletes the tissue of glucose, increasing alanine and lactate, and resulted in no correlation between these in vivo and ex vivo metabolite concentrations.Conclusion:Within defined limitations, ex vivo astrocytoma biopsy HRMAS 1H spectra have similar metabolic profiles to that obtained in vivo and therefore detailed ex vivo characterization of glioma biopsies can directly relate to the original tumor. J. Magn. Reson. Imaging 2010; 31: 289–297. © 2010 Wiley‐Liss, Inc.
Improved blood suppression in three‐dimensional (3D) fast spin‐echo (FSE) vessel wall imaging using a combination of double inversion‐recovery (DIR) and diffusion sensitizing gradient (DSG) preparations
Authors: Makhijani Mahender K. , Hu Houchun H. , Pohost Gerry M. , Nayak Krishna S. 
Published: January 2010

AbstractPurpose:To provide improved blood suppression in three‐dimensional inner‐volume fast spin‐echo (3D IV‐FSE) carotid vessel wall imaging by using a hybrid preparation consisting of double inversion‐recovery (DIR) and diffusion sensitizing gradients (DSG).Materials and Methods:Multicontrast black‐blood MRI is widely used for vessel wall imaging and characterization of atherosclerotic plaque composition. Blood suppression is difficult when using 3D volumetric imaging techniques. DIR approaches do not provide robust blood suppression due to incomplete replacement of blood spins, and DSG approaches compromise vessel wall signal, reducing the lumen‐wall contrast‐to‐noise ratio efficiency (CNReff). In this work a hybrid DIR+DSG preparation is developed and optimized for blood suppression, vessel wall signal preservation, and vessel‐wall contrast in 3D IV‐FSE imaging. Cardiac gated T1‐weighted carotid vessel wall images were acquired in five volunteers with 0.5 × 0.5 × 2.5 mm3 spatial resolution in 80 seconds.Results:Data from healthy volunteers indicate that the proposed method yields a statistically significant (P < 0.01) improvement in blood suppression and lumen‐wall CNReff compared to standard DIR and standard DSG methods alone.Conclusion:A combination of DIR and DSG preparations can provide improved blood suppression and lumen‐wall CNReff for 3D IV‐FSE vessel wall imaging. J. Magn. Reson. Imaging 2010; 31: 398–405. © 2010 Wiley‐Liss, Inc.