bluuebunny/crossref_metadata_2025_split huggingface dataset:
MRI measurements of carotid plaque in the atherosclerosis risk in communities (ARIC) study: Methods, reliability and descriptive statistics
Authors: Wasserman Bruce A. , Astor Brad C. , Sharrett A. Richey , Swingen Cory , Catellier Diane 
Published: January 2010

AbstractPurpose:To measure carotid plaque components using MRI and estimate reliability in the population‐based Atherosclerosis Risk in Communities (ARIC) study.Materials and Methods:Contrast‐enhanced high‐resolution (0.51 × 0.58 × 2 mm3) MRI images were acquired through internal (ICA) and common carotid arteries (CCA) of 2066 ARIC participants at four sites. Sixty‐one exams were repeated and 164 pairs had repeated interpretations. Plaque component thicknesses, areas and volumes over eight slices (1.6‐cm segment) were measured. Intraplaque hemorrhage was recorded. Reliability was evaluated by intraclass correlations and κ statistics.Results:There were 1769 successful MRI exams (mean age 71 years; 57% females; 81% white; 19% African‐Americans). Repeat scan reliability was highest for CCA lumen area (0.94) and maximum wall thickness (0.89), ICA lumen area (0.89) and maximum wall thickness (0.77) and total wall volume (0.79), and lowest for small structures—core volume (0.30) and mean cap thickness (0.38). Overall reliability was primarily related to reader variability rather than scan acquisition. K's for presence of core, calcification and hemorrhage were fair to good. White men had the thickest plaques (average maximum ICA wall thickness = 2.3 mm) and the most cores (34%).Conclusion:The most important limiting factor for MRI measurements of plaque components is reader variability. Measurement error depends largely on the analyzed structure's size. J. Magn. Reson. Imaging 2010; 31: 406–415. © 2010 Wiley‐Liss, Inc.
Blood‐oxygen level dependent MRI measures of cerebrovascular reactivity using a controlled respiratory challenge: Reproducibility and gender differences
Authors: Kassner Andrea , Winter Jeff D. , Poublanc Julien , Mikulis David J. , Crawley Adrian P. 
Published: January 2010

AbstractPurpose:To evaluate the reproducibility and gender differences in cerebrovascular reactivity (CVR) measurements obtained using the blood‐oxygen level dependent (BOLD) response to controlled changes in end‐tidal partial pressure of carbon dioxide (PETCO2).Materials and Methods:We obtained ethical approval to image 19 healthy volunteers (10 men, 9 women) on a 1.5 Tesla (T) MRI scanner twice on two separate days using identical procedures. CVR images were generated by collecting BOLD MRI data during controlled changes in PETCO2 induced by a sequential gas delivery system.Results:Using the intraclass correlation coefficient (ICC), we demonstrated excellent within‐day CVR measures in gray matter (GM) (ICC = 0.92) and white matter (WM) (ICC = 0.88) regions, excellent between‐day reproducibility in GM (ICC = 0.81), and good between‐day reproducibility in the WM (ICC = 0.66). CVR values between men and women were significantly different in the GM and WM. Men exhibited a 22 ± 2% greater CVR in GM and a 17 ± 2% greater CVR in WM compared with females.Conclusion:Our results demonstrate the reliability of BOLD MRI CVR measurements obtained using a controlled cerebrovascular challenge. Using this technique, we also revealed significantly increased BOLD response to CO2 in males compared with females. J. Magn. Reson. Imaging 2010; 31: 298–304. © 2010 Wiley‐Liss, Inc.
Diffusion tensor MRI: Preliminary anisotropy measures and mapping of breast tumors
Authors: Partridge Savannah C. , Ziadloo Ali , Murthy Revathi , White Steven W. , Peacock Sue , Eby Peter R. , DeMartini Wendy B. , Lehman Constance D. 
Published: January 2010

AbstractPurpose:To investigate whether diffusion tensor imaging (DTI) measures of anisotropy in breast tumors are different from normal breast tissue and can improve the discrimination between benign and malignant lesions.Materials and Methods:The study included 81 women with 105 breast lesions (76 malignant, 29 benign). DTI was performed during breast MRI examinations, and fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured for breast lesions and normal tissue in each subject. FA and ADC were compared between cancers, benign lesions, and normal tissue by univariate and multivariate analyses.Results:The FA of carcinomas (mean ± SD: 0.24 ± 0.07) was significantly lower than normal breast tissue in the same subjects (0.29 ± 0.07; P < 0.0001). Multiple logistic regression showed that FA and ADC were each independent discriminators of malignancy (P < 0.0001), and that FA improved discrimination between cancer and normal tissue over ADC alone. However, there was no difference in FA between malignant and benign lesions (P = 0.98).Conclusion:Diffusion anisotropy is significantly lower in breast cancers than normal tissue, which may reflect alterations in tissue organization. Our preliminary results suggest that FA adds incremental value over ADC alone for discriminating malignant from normal tissue but does not help with distinguishing benign from malignant lesions. J. Magn. Reson. Imaging 2010; 31: 339–347. © 2010 Wiley‐Liss, Inc.
Visualization of deep veins and detection of deep vein thrombosis (DVT) with balanced turbo field echo (b‐TFE) and contrast‐enhanced T1 fast field echo (CE‐FFE) using a blood pool agent (BPA)
Authors: Enden Tone , Storås Tryggve H. , Negård Anne , Haig Ylva , Sandvik Leiv , Gjesdal Kjell‐Inge , Sandset Per Morten , Kløw Nils‐Einar 
Published: January 2010

AbstractPurpose:To assess image quality, vessel visualization, preliminary diagnostic properties, and interobserver variability of a novel balanced turbo field echo (b‐TFE) sequence and contrast‐enhanced T1 fast field echo (CE‐FFE) sequence with blood pool agent (BPA).Materials and Methods:A total of 15 healthy volunteers and six patients with ultrasound‐verified proximal deep vein thrombosis (DVT) were examined from the inferior vena cava (IVC) to the proximal calf veins.Results:The great majority of deep veins were completely visualized on both sequences. In healthy volunteers the IVC was completely visualized in five b‐TFE and 11 CE‐FFE scans, and partially in seven b‐TFE and four CE‐FFE scans (P = 0.008). Poorest image quality was in the pelvis. Contrast‐to‐noise ratio (CNR) was higher on b‐TFE compared to CE‐FFE, with significant difference in calf images (P = 0.036). Sensitivity was 100% for proximal DVT with both methods. Specificity was 70% (CE‐FFE) and 80% (b‐TFE) for proximal femoral DVT; 100% in distal femoral. Interobserver reliability was kappa 1.0 (b‐TFE), 0.9 (CE‐FFE) for proximal, and overall poor for distal DVT.Conclusion:Contrast‐enhancement did not add valuable information in visualizing deep veins of the lower limbs compared to b‐TFE, though the IVC was slightly better visualized. Diagnostic properties and interobserver reliability of both sequences were good for proximal DVT and poor for distal DVT. J. Magn. Reson. Imaging 2010; 31: 416–424. © 2010 Wiley‐Liss, Inc.
Diagnostic value of T2‐weighted imaging for the detection of superficial cranial artery inflammation in giant cell arteritis
Authors: Geiger Julia , Bley Thorsten , Uhl Markus , Frydrychowicz Alex , Langer Mathias , Markl Michael 
Published: January 2010

AbstractPurpose:To evaluate the diagnostic value of T2‐weighted radial MR imaging for the detection of superficial cranial arteries' inflammatory involvement in patients with giant cell arteritis (GCA).Materials and Methods:Forty‐three patients with suspected giant cell arteritis underwent 3 Tesla (T) high‐field MRI. T2‐weighted inversion recovery (IR) fast spin echo images with radial sampling (BLADE‐technique) were acquired and compared with postcontrast T1‐weighted spin echo images.Results:T2‐weighted images revealed mural edema in the superficial cranial arteries in 11 patients in concordance with severe inflammatory contrast enhancement in T1‐weighted images (grade 4 in a 4‐point ranking scale). Excellent correlation (r = 0.82; P < 0.001) of measured wall thickness in T1‐ and T2‐weighted images was achieved.Conclusion:The results of this study indicate the potential of radial T2 weighted imaging for a first detection of inflammatory changes in the small superficial cranial arteries without the need for contrast medium. Future studies are needed to evaluate the influence of spatial resolution of the T2 images and to improve the detection of moderate GCA related changes in vessel inflammation. J. Magn. Reson. Imaging 2010; 31: 470–474. © 2010 Wiley‐Liss, Inc.
Overlap syndrome of autoimmune chronic liver diseases: MRI findings
Authors: Hyslop W. Brian , Kierans Andrea S. , Leonardou Polytimi , Fritchie Karen , Darling Jama , Elazazzi Mohamed , Semelka Richard C. 
Published: January 2010

AbstractPurpose:To describe the MR findings of overlap syndromes of autoimmune chronic liver diseases.Methods:Review of clinical and radiological databases between March 2001 and July 2008 for patients with a clinical diagnosis and liver biopsy features compatible with overlap syndrome who had also undergone an abdominal MRI yielded 15 adult patients. MR features of overlap syndrome were reviewed by two radiologists by consensus. Two radiologists independently reviewed the studies in a blinded fashion for primary sclerosing cholangitis (PSC)‐type or non‐PSC‐type features to assess interobserver agreement.Results:PSC‐type and non‐PSC‐type overlap syndrome had distinctive MR features. In the consensus review, all 12 patients with PSC‐type overlap syndrome were correctly identified. Imaging findings included central macroregeneration (N = 9), peripheral atrophy (N = 7), biliary duct beading (N = 12), biliary dilation (N = 10), or a combination of all four findings (N = 7). The presence of any of the first three features had 100% specificity for a PSC‐type overlap syndrome. Patients with non‐PSC‐type overlap (N = 3) showed relatively normal liver morphology (N = 3) and minimal biliary ductal dilatation in one patient. There was good interobserver agreement (kappa = 0.76).Conclusion:Patients with serologic or pathologic evidence of AIH or PBC with imaging features of PSC may have PSC‐type overlap syndrome. J. Magn. Reson. Imaging 2010; 31: 383–389. © 2010 Wiley‐Liss, Inc.
T1‐weighted–SPACE dark blood whole body magnetic resonance angiography (DB‐WBMRA): Initial experience
Authors: Mihai Georgeta , Chung Yiu‐Cho , Merchant Ali , Simonetti Orlando P. , Rajagopalan Sanjay 
Published: January 2010

AbstractPurpose:To evaluate the feasibility of the dark blood fast spin echo (FSE) T1‐weighted–Sampling Perfection with Application of optimized Contrasts using different flip angle Evolution (T1w‐SPACE) sequence in assessing whole body arterial wall information from the extracranial carotids to the popliteal artery.Materials and Methods:Twenty‐eight subjects were subjected to noncontrast, dark blood whole body magnetic resonance angiography (DB‐WBMRA) using a T1w‐SPACE sequence optimized for each of the individual stations: carotid artery, thoracic aorta, abdominal aorta, and thigh/superficial femoral artery (SFA). Image quality/vessel wall visualization and the time required to image the four stations were evaluated. Two observers checked the reproducibility of vessel wall depiction by performing quantitative measurements in registered initial and repeat studies (six subjects) of vessel wall and lumen area at 17 locations along the arterial tree.Results:In 25 of the 28 scanned subjects, dark blood arterial images acquired in approximately 1 hour total imaging time allowed whole body arterial vessel wall visualization. Quantitative measurements showed high correlation between the initial and repeat studies for each of the observers as well as high interobserver reproducibility (r > 0.95; P < 0.01).Conclusion:DB‐WBMRA using T1w‐SPACE is feasible and can be performed with a high degree of reliability. J. Magn. Reson. Imaging 2010; 31: 502–509. © 2010 Wiley‐Liss, Inc.
MRI assessment of pacing induced ventricular dyssynchrony in an isolated human heart
Authors: Eggen Michael D. , Bateman Michael G. , Rolfes Christopher D. , Howard Stephen A. , Swingen Cory M. , Iaizzo Paul A. 
Published: January 2010

AbstractThis study demonstrates the capabilities of MRI in the assessment of cardiac pacing induced ventricular dyssynchrony, and the findings support the need for employing more physiological pacing. A human donor heart deemed non‐viable for transplantation, was reanimated using an MR compatible, four‐chamber working perfusion system. The heart was imaged using a 1.5T MR scanner while being paced from the right ventricular apex (RVA) via an epicardial placed lead. Four‐chamber, short‐axis, and tagged short‐axis cines were acquired in order to track wall motion and intramyocardial strain during pacing. The results of this study revealed that the activation patterns of the left ventricle (LV) during RVA pacing demonstrated intraventricular dyssynchrony; as the left ventricular mechanical activation proceeded from the septum and anterior wall to the lateral wall, with the posterior wall being activated last. As such, the time difference to peak contraction between the septum and lateral wall was ∼125 msec. Likewise, interventricular dyssynchrony was demonstrated from the four‐chamber cine as the time difference between the peak LV and RV free wall motion was 180 msec. With the ongoing development of MR safe and MR compatible pacing systems, we can expect MRI to be added to the list of imaging modalities used to optimize cardiac resynchronization therapy (CRT) and/or alternate site pacing. J. Magn. Reson. Imaging 2010; 31: 466–469. © 2010 Wiley‐Liss, Inc.
Improved fat–water reconstruction algorithm with graphics hardware acceleration
Authors: Johnson David H. , Narayan Sreenath , Flask Chris A. , Wilson David L. 
Published: January 2010

AbstractPurpose:To develop a fast and robust Iterative Decomposition of water and fat with Echo Asymmetry and Least‐squares (IDEAL) reconstruction algorithm using graphics processor unit (GPU) computation.Materials and Methods:The fat–water reconstruction was expedited by vectorizing the fat–water parameter estimation, which was implemented on a graphics card to evaluate potential speed increases due to data‐parallelization. In addition, we vectorized and compared Brent's method with golden section search for the optimization of the unknown field inhomogeneity parameter (ψ) in the IDEAL equations. The algorithm was made more robust to fat–water ambiguities using a modified planar extrapolation (MPE) of ψ algorithm. As compared to simple planar extrapolation (PE), the use of an averaging filter in MPE made the reconstruction more robust to neighborhoods poorly fit by a two‐dimensional plane.Results:Fat–water reconstruction time was reduced by up to a factor of 11.6 on a GPU as compared to CPU‐only reconstruction. The MPE algorithms incorrectly assigned fewer pixels than PE using careful manual correction as a gold standard (0.7% versus 4.5%; P < 10−4). Brent's method used fewer iterations than golden section search in the vast majority of pixels (6.8 ± 1.5 versus 9.6 ± 1.6 iterations).Conclusion:Data sets acquired on a high field scanner can be quickly and robustly reconstructed using our algorithm. A GPU implementation results in significant time savings, which will become increasingly important with the trend toward high resolution mouse and human imaging. J. Magn. Reson. Imaging 2010; 31: 457–465. © 2010 Wiley‐Liss, Inc.
Study of the features of proton MR spectroscopy (1H‐MRS) on amyotrophic lateral sclerosis
Authors: Han Jing , Ma Lin 
Published: January 2010

AbstractPurpose:To study the features of proton magnetic resonance spectroscopy (1H‐MRS) on amyotrophic lateral sclerosis (ALS) and its relation with clinical scale.Materials and Methods:Fifteen patients with definite or probable ALS and 15 age‐ and gender‐matched normal controls were enrolled. 1H‐MRS was performed on a 3.0 Tesla GE imaging system (GE Healthcare, Milwaukee, WI). TE‐averaged Point Resolved Selective Spectroscopy was used. N‐acetylaspartate (NAA), creatine (Cr), Glu, and Glx (glutamate + glutamine) values of the motor cortex and posterior limb of internal capsule were acquired. The t‐test was used to compare differences between groups, and the correlations between the above values and clinical scale were analyzed.Results:The motor area and posterior limb of the internal capsule of ALS patients had lower NAA/Cr (1.91 ± 0.34, 1.53 ± 0.17) compared with normal subjects (2.23 ± 0.33, 1.66 ± 0.07), and the differences between groups were statistically significant (P < 0.01, 0.01). ALS patients had higher Glu/Cr (0.34 ± 0.05, 0.29 ± 0.06) and Glx/Cr (0.40 ± 0.04, 0.33 ± 0.06) compared with normal subjects (0.30 ± 0.03, 0.25 ± 0.04) and (0.32 ± 0.05, 0.26 ± 0.03), and the differences between groups were statistically significant (P < 0.01, 0.01). The Norris scale was negatively correlated with Glx/Cr of primary motor cortex by lineal correlation analysis (r = −0.75), and this correlation had statistical significance (F = 16.60; P = 0.001).Conclusion:Neuronal loss and Glu+Gln increase can be detected by using proton MRS in ALS patients. 1H‐MRS is an useful tool in reflecting the characteristic changes of metabolite in ALS. J. Magn. Reson. Imaging 2010; 31: 457–465. © 2010 Wiley‐Liss, Inc.
Enhancement of liver parenchyma after injection of hepatocyte‐specific MRI contrast media: A comparison of gadoxetic acid and gadobenate dimeglumine
Authors: Filippone Antonella , Blakeborough Anthony , Breuer Josy , Grazioli Luigi , Gschwend Simone , Hammerstingl Renate , Heinz‐Peer Gertraud , Kittner Thomas , Laghi Andrea , Leen Edward , Lencioni Riccardo , Lucidarme Olivier , Remplik Philipp , Robinson Philip J. , Ruehm Stefan G. , Schaefer Fritz , Stoupis Christoforos , Tombach Bernd , Valette Pierre‐Jean , Zech Christoph J. , Huppertz Alexander 
Published: January 2010

AbstractPurpose:To compare enhancement of liver parenchyma in MR imaging after injection of hepatocyte‐specific contrast media.Materials and Methods:Patients (n = 295) with known/suspected focal liver lesions randomly received 0.025 mmol gadoxetic acid/kg body weight or 0.05 mmol gadobenate dimeglumine/kg body weight by means of bolus injection. MR imaging was performed before and immediately after injection, and in the delayed phase at approved time points (20 min after injection of gadoxetic acid and 40 min after injection of gadobenate dimeglumine). The relative liver enhancement for the overall population and a cirrhotic subgroup was compared in T1‐weighted GRE sequences. An independent radiologist performed signal intensity measurements. Enhancement ratios were compared using confidence intervals (CIs).Results:The relative liver enhancement in the overall population was superior with gadoxetic acid (57.24%) versus gadobenate dimeglumine (32.77%) in the delayed‐imaging phase. The enhancement ratio between the contrast media was statistically significant at 1.75 (95% CI: 1.46–2.13). In the delayed phase, the enhancement of cirrhotic liver with gadoxetic acid (57.00%) was comparable to that in the overall population. Enhancement with gadobenate dimeglumine was inferior in cirrhotic liver parenchyma (26.85%).Conclusion:In the delayed, hepatocyte‐specific phase, liver enhancement after injection of gadoxetic acid was superior to that obtained with gadobenate dimeglumine. J. Magn. Reson. Imaging 2010; 31: 356–364. © 2010 Wiley‐Liss, Inc.
Quantifying in vivo hemodynamic response to exercise in patients with intermittent claudication and abdominal aortic aneurysms using cine phase‐contrast MRI
Authors: Tenforde Adam S. , Cheng Christopher P. , Suh Ga‐Young , Herfkens Robert J. , Dalman Ronald L. , Taylor Charles A. 
Published: January 2010

AbstractPurpose:To evaluate rest and exercise hemodynamics in patients with abdominal aortic aneurysms (AAA) and peripheral occlusive disease (claudicants) using phase‐contrast MRI.Materials and Methods:Blood velocities were acquired by means of cardiac‐gated cine phase‐contrast in a 0.5 Tesla (T) open MRI. Volumetric flow was calculated at the supraceliac (SC), infrarenal (IR), and mid‐aneurysm (MA) levels during rest and upright cycling exercise using an MR‐compatible exercise cycle.Results:Mean blood flow increased during exercise (AAA: 130%, Claudicants: 136% of resting heart rate) at the SC and IR levels for AAA participants (2.6 ± 0.6 versus 5.8 ± 1.6 L/min, P < 0.001 and 0.8 ± 0.4 versus 5.1 ± 1.7 L/min, P < 0.001) and claudicants (2.3 ± 0.5 versus 4.5 ± 0.9 L/min, P < 0.005 and 0.8 ± 0.2 versus 3.3 ± 0.9 L/min, P < 0.005). AAA participants had a significant decrease in renal and digestive blood flow from rest to exercise (1.8 ± 0.7 to 0.7 ± 0.6 L/min, P < 0.01). The decrease in renal and digestive blood flow during exercise correlated with daily activity level for claudicants (R = 0.81).Conclusion:Abdominal aortic hemodynamic changes due to lower extremity exercise can be quantified in patients with AAA and claudication using PC‐MRI. The redistribution of blood flow during exercise was significant and different between the two disease states. J. Magn. Reson. Imaging 2010; 31: 425–429. © 2010 Wiley‐Liss, Inc.
Comparison of two different injection rates of gadoxetic acid for arterial phase MRI of the liver
Authors: Chung Sang‐Hoon , Kim Myeong‐Jin , Choi Jin‐Young , Hong Hye‐Suk 
Published: January 2010

AbstractPurpose:To compare two different injection rates for gadoxetic acid‐enhanced hepatic arterial phase images on hepatic dynamic MRI.Materials and Methods:Hepatic arterial phase images were obtained after an intravenous bolus injection of gadoxetic acid at a rate of 1 mL/second in 62 patients and 2 mL/second in 64 patients on a 3 Tesla MR scanner using a test‐bolus injection method. The signal‐to‐noise ratios (SNR) of the liver, portal vein, hepatic vein, aorta, spleen and pancreas were measured. The contrast‐to‐noise ratio (CNR) of hypervascular hepatic tumors was calculated. Two radiologists independently scored items to evaluate image quality of hepatic arterial phase and detected hypervascular hepatocellular carcinoma (HCC).Results:The SNR of the aorta on the arterial phase images was significantly higher in the 1 mL/second group (235.43 ± 82.59) than in the 2 mL/second group (190.94 ± 96.90, P < 0.05). The SNRs of the liver, spleen and pancreas, the CNRs of hypervascular hepatic tumors, the detection rate of hypervascular HCC and subjective ratings for the optimal arterial enhancement were comparable between the two groups.Conclusion:Injection rates of 2 mL/second and 1 mL/second provided comparable image qualities on arterial phase images of hepatic dynamic MRI using gadoxetic acid. J. Magn. Reson. Imaging 2010; 31: 365–372. © 2010 Wiley‐Liss, Inc.