bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of [14C]ABT‐770, matrix metalloproteinase inhibitor (MMPI), labelled in the phenoxy ring
Authors: Raja Shirish N. 
Published: August 2003

AbstractThe MMPI [14C]ABT‐770 (1), N‐[(1S)‐1‐[(4,4‐Dimethyl‐2,5‐dioxo‐1‐imi‐dazolidinyl)methyl]]‐2‐[[4′‐(trifluoromethoxy)[1,1′‐biphenyl]‐4‐yl]oxy]ethyl]‐N‐hydroxyformamide was synthesized in 8 steps using 4‐bromophenol‐UL‐14C (10) as a starting material. The Carbon‐14 label was introduced in one of the metabolically stable biphenyl rings. The key sequence of the synthesis was a three‐step one‐pot reaction in which the hydantoin moiety was introduced, the imine oxidized and further hydrolyzed to get the penultimate precursor to [14C]ABT‐770 (1) in 56% yield. Copyright © 2003 John Wiley & Sons, Ltd.
Sub‐acute changes in lesion conspicuity and geometry following MR‐guided radiofrequency ablation
Authors: Lazebnik Roee S. , Weinberg Brent D. , Breen Michael S. , Lewin Jonathan S. , Wilson David L. 
Published: August 2003

AbstractPurposeTo evaluate MR signal and lesion zone volume evolution through the sub‐acute phase following image‐guided radiofrequency (RF) thermal ablation.Materials and MethodsFor many tissues, including muscle and liver, thermal lesions that result from RF heating have a characteristic two‐boundary appearance featuring an inner core (zone I) surrounded by a hyper‐intense margin (zone II) and normal tissue (zone III), found in both T2 and contrast enhanced (CE) T1‐weighted MR images, both immediately post‐ablation and four days later. First, we compared corresponding points between manually segmented zone boundaries apparent in T2‐ and CE T1‐weighted images. Second, we examined the contrast‐to‐noise ratio (CNR) between all zone combinations. Third, we quantified the volume of zone I, zone II, and the entire lesion using a three‐dimensional lesion geometry model fitted to segmented images.ResultsOn a slice‐by‐slice basis, no statistically significant differences were found between zone boundaries apparent in T2 and CE T1‐weighted images. The contrast to noise ratio (CNR) of zone I vs. zone II, zone I vs. background muscle, and zone II vs. background muscle was always equal or greater for T2‐weighted images than for CE T1‐weighted images. In addition, by day four, zone II significantly increased in intensity compared to background muscle. The median Zone I volume increase was 44.2% (42.6%) using T2 weighted images and 55.5% (68.7% interquartile range) using CE T1‐ weighted images. This expansion likely corresponds to an enlargement of the ablated, coagulative necrosis, region. The median Zone II volume increase was 15.0% (42.6%) using T2‐ weighted images 1.5% (38.8%) using CE T1‐weighted images.Conclusions1) There are no significant differences between the apparent zone boundaries in T2‐ and CE T1‐weighted images; 2) CNR is equal or greater for T2‐weighted images as compared to CE T1‐images; and 3) both the inner and outer lesion zone volumes typically increase several days post‐ablation. J. Magn. Reson. Imaging 2003;18:353–359. © 2003 Wiley‐Liss, Inc.
Single breath‐hold diffusion‐weighted imaging of the abdomen
Authors: Chow Lawrence C. , Bammer Roland , Moseley Michael E. , Sommer F. Graham 
Published: August 2003

AbstractPurposeTo generate high quality diffusion‐weighted images (DWI) and corresponding isotropic ADC maps of the abdomen with full organ (kidneys) coverage in a single breath‐hold.Materials and MethodsDWI was performed in 12 healthy subjects with an asymmetric, spin‐echo, single‐shot EPI readout on a system with high performance gradients (40 mT/minute). The isotropic diffusion coefficient 〈D〉 was measured from 〈D〉 maps and SNR was determined for both diffusion‐weighted and reference images in the liver, spleen, pancreas, and kidneys. In six patients, single‐axis diffusion encoding along three orthogonal axes (12 NEX) was employed to assess anisotropic diffusion in kidneys.ResultsThis technique yielded images of quality and resolution which compares favorably to that of prior work. SNR ranged from 27.0 in liver to 44.1 in kidneys for the diffusion‐weighted images, and from 19.6 in liver to 39.0 in kidneys in reference images. ADCs obtained in the renal medulla, renal cortex, liver, spleen, and pancreas were (2091 ± 55) × 10−6, (2580 ± 53) × 10−6, (1697 ± 52) × 10−6, (1047 ± 82) × 10−6, and (2605 ± 168) × 10−6 mm2/second, respectively (mean ± SE). Apparent diffusion coefficient (ADC) in the renal medulla and cortex were significantly different by paired t‐test (P = 4.22 × 10−10). Renal medulla and cortex yielded anisotropy indices (AI) of 0.129 and 0.067, respectively.Conclusions1) Single‐shot SE EPI DWI in the abdomen with this technique provides high quality images and 〈D〉 maps with full organ coverage in a single breath‐hold; 2) ADCs obtained in the renal medulla and cortex are significantly different; and 3) diffusion within the renal medulla is moderately anisotropic. J. Magn. Reson. Imaging 2003;18:377–382. © 2003 Wiley‐Liss, Inc.
Application of a B‐spline active surface technique to the measurement of cervical cord volume in multiple sclerosis from three‐dimensional MR images
Authors: Hickman Simon J. , Coulon Olivier , Parker Geoffrey J.M. , Barker Gareth J. , Stevenson Valerie L. , Chard Declan T. , Arridge Simon R. , Thompson Alan J. , Miller David H. 
Published: August 2003

AbstractPurposeTo evaluate the ability of a B‐spline active surface technique to detect cervical spinal cord atrophy due to multiple sclerosis (MS) compared with intensity‐based contouring.Materials and MethodsIn a previously reported study, the cervical spinal cords of 28 MS patients and 13 age‐matched controls were imaged with a volume‐acquired inversion‐prepared fast spoiled gradient echo sequence at baseline and after one year. The images were reanalyzed using the B‐spline technique and the results compared with the results obtained in the original report using intensity‐based contouring.ResultsThe mean cervical spinal cord volume determined by the active surface programme was 6487 mm3 in 28 patients compared with 7117 mm3 in controls (P = 0.002, corrected for age and gender). The patients' cervical spinal cord volumes were associated with expanded disability status scale scores (parameter estimate = −1.21 × 10−3, r2 = 0.39, P = 0.001). The patients' cervical spinal cord volumes did not decrease significantly over one year, unlike the mean cervical spinal cord areas at C2/3 calculated using intensity‐based contouring.ConclusionThe active surface technique can detect cervical spinal cord atrophy due to MS, which has functional significance. However, this methodology is less sensitive at detecting small serial changes compared with the previously reported method. J. Magn. Reson. Imaging 2003;18:368–371. © 2003 Wiley‐Liss, Inc.
Single‐shot spiral image acquisition with embedded z‐shimming for susceptibility signal recovery
Authors: Guo Hua , Song Allen W. 
Published: August 2003

AbstractPurposeTo efficiently and effectively recover the susceptibility‐induced signal losses for functional MRI (fMRI) experiments.Materials and MethodsThe signal losses near air/tissue interfaces at the ventral brain regions introduce difficulties in the neuroimaging studies concerned with brain functions such as memory, emotion, and olfaction processes. The z‐shimming technique has been introduced in fMRI image acquisition to recover such losses. One significant drawback of such an approach is its time consuming nature. In this report, a single‐shot spiral imaging method, which combines spiral‐in and spiral‐out acquisitions along with embedded z‐shimming gradient, was proposed and implemented to achieve signal recovery without sacrificing temporal resolution.ResultsUsing the proposed method, final images were shown in the ventral brain regions. The images were acquired with a throughput of 16 slices/second and demonstrated effectiveness and efficiency in signal recovery near air/tissue interfaces.ConclusionUniform recovery can be achieved efficiently near air/tissue interfaces where susceptibility‐induced spatial gradients are pronounced. We anticipate that our method would be well suited for fMRI studies involving the ventral brain areas. J. Magn. Reson. Imaging 2003;18:389–395. © 2003 Wiley‐Liss, Inc.
The interrupted rim sign in acute cholecystitis: A method to identify the gangrenous form with MRI
Authors: Pedrosa Ivan , Guarise Alessandro , Goldsmith Jeffrey , Procacci Carlo , Rofsky Neil M. 
Published: August 2003

AbstractWe present the imaging findings on MR of a patient with acute gangrenous cholecystitis that demonstrated patchy enhancement of the gallbladder mucosa on gadolinium‐enhanced fat‐saturated T1‐weighted gradient echo images. This interrupted rim of mucosal enhancement correlated with patchy areas of necrosis and inflammation of the gallbladder mucosa on the histopathological examination. J. Magn. Reson. Imaging 2003;18:360–363. © 2003 Wiley‐Liss, Inc.
Assessment of normal, inflammatory, and tumor‐bearing lymph nodes with contrast‐enhanced interstitial magnetic resonance lymphography: Preliminary results in rabbits
Authors: Herborn Christoph U. , Vogt Florian M. , Lauenstein Thomas C. , Goyen Mathias , Dirsch Olaf , Corot Claire , Debatin Jörg F. , Ruehm Stefan G. 
Published: August 2003

AbstractPurposeTo assess different gadolinium (Gd)‐based contrast agents for interstitial magnetic resonance (MR) lymphography in normal, inflammatory, and tumor‐bearing lymph nodes in rabbits.Materials and MethodsThree paramagnetic contrast agents were assessed: a standard extracellular 0.5 M Gd‐chelate, gadoterate meglumine (Gd‐DOTA), and two macromolecular agents, P792 and P760 (all Guerbet, Aulnay‐sous‐Bois, France). A volume of 0.5 mL of each agent were injected subcutaneously into the dorsal footpads of six rabbits (three groups, 18 rabbits). Imaging was performed prior to as well as two weeks following induction of either reactive (complete Freund adjuvant) or tumorous (VX2 tumor) lymph nodes. T1‐weighted three‐dimensional gradient‐echo and maximum intensity projection (MIP) images were obtained up to 120 minutes as well as 24 hours after administration of the different compounds. Signal‐to‐noise ratios (SNRs) of enhancing lymph nodes were calculated. The different compounds were compared regarding nodal enhancement over time, depiction of regional nodes, and lymphatic vessels. Furthermore, enhancement patterns were compared between normal, inflammatory, and metastasized nodes.ResultsInguinal and iliac lymph nodes and lymph vessels revealed enhancement following interstitial injection of all evaluated compounds. For all agents, inflammatory lymph nodes revealed no significantly different SNRs compared to normal nodes (P > 0.2), whereas tumorous nodes showed signal voids and significantly lower SNRs (P < 0.05). Compared to P760 and P792, depiction of tumor‐bearing nodes with Gd‐DOTA was less reliable.ConclusionInterstitial MR lymphography with P760 and P792 allows differentiation of tumor‐bearing lymph nodes from reactive inflammatory and normal nodes based on a contrast uptake pattern assessed qualitatively as well as quantitatively.J. Magn. Reson. Imaging 2003;18:328–335. © 2003 Wiley‐Liss, Inc.
T1ρ‐relaxation mapping of human femoral‐tibial cartilage in vivo
Authors: Regatte Ravinder Reddy , Akella Sarma V.S. , Wheaton Andrew J. , Borthakur Arijitt , Kneeland J. Bruce , Reddy Ravinder 
Published: August 2003

AbstractPurposeTo demonstrate the in vivo feasibility of measuring spin‐lattice relaxation time in the rotating frame (T1ρ); and T1ρ‐dispersion in human femoral cartilage. Furthermore, we aimed to compute the baseline T1ρ‐relaxation times and spin‐lock contrast (SLC) maps on healthy volunteers, and compare relaxation times and signal‐to‐noise ratio (SNR) with corresponding T2‐weighted images.Materials and MethodsAll MR imaging experiments were performed on a 1.5 T GE Signa scanner (GEMS, Milwaukee, WI) using a custom built 15‐cm transmit‐receive quadrature birdcage radio‐frequency (RF) coil. The T1ρ‐prepared magnetization was imaged with a single‐slice two‐dimensional fast spin‐echo (FSE) pulse sequence preencoded with a three‐pulse cluster consisting of two hard 90° pulses and a low power spin‐lock pulse. T1ρ‐dispersion imaging was performed by varying the spin‐lock frequency from 100 to 500 Hz in five steps in addition to varying the length of the spin‐lock pulse.ResultsThe average T1ρ‐relaxation times in the weight‐bearing (WB) and nonweight‐bearing (NWB) regions of the femoral condyle were 42.2 ± 3.6 msec and 55.7 ± 2.3 msec (mean ± SD, N = 5, P < 0.0001), respectively. In the same regions, the corresponding T2‐relaxation times were 31.8 ± 1.5 msec and 37.6 ± 3.6 msec (mean ± SD, N = 5, P < 0.0099). T1ρ‐weighted images have ∼20%–30% higher SNR than the corresponding T2‐weighted images for similar echo time. The average SLC in the WB region of femoral cartilage was 30 ±4.0%. Furthermore, SLC maps provide better contrast between fluid and articular surface of femoral‐tibial joint than T1ρ‐maps. The T1ρ‐relaxation times varied from 32 msec to 42 msec (∼31%) in the WB and 37 msec to 56 msec (∼51%) in NWB regions of femoral condyle, respectively, in the frequency range 0–500 Hz (T1ρ‐dispersion).ConclusionThe feasibility of performing in vivo T1ρ relaxation mapping in femoral cartilage at 1.5T clinical scanner without exceeding Food and Drug Administration (FDA) limits on specific absorption rate (SAR) of RF energy was demonstrated. J. Magn. Reson. Imaging 2003;18:336–341. © 2003 Wiley‐Liss, Inc.
Spatial resolution of numerical models of man and calculated specific absorption rate using the FDTD method: A study at 64 MHz in a magnetic resonance imaging coil
Authors: Collins Christopher M. , Smith Michael B. 
Published: August 2003

AbstractPurposeTo examine how fine a model resolution is necessary for calculation of specific energy absorption rate (SAR) for the human head in regions as small as 1 g.Materials and MethodsHere we perform a simple study comparing the maximum SAR averaged over any 1 cm3 and SAR averaged over the entire head for several models of the same human head within the same radiofrequency coil, but with spatial resolutions varying from 8–100 Yee cells per cm3.ResultsOver the range of model resolutions from 8–100 Yee cells per cm3, there is only a 16% variation in maximum SAR in any 1 cm3 of tissue in the head, and only a 7% variation in SAR averaged over the entire head.ConclusionWhile it is always desirable to perform SAR calculations with the greatest possible accuracy, in calculations of the maximum SAR levels in any 1 cm3 of tissue, spatial resolutions greater than 5 mm may not yield notably different results than those with a spatial resolution of 5 mm. J. Magn. Reson. Imaging 2003;18:383–388. © 2003 Wiley‐Liss, Inc.
Quantitative T2 in the occipital lobe: The role of the CPMG refocusing rate
Authors: Stefanovic Bojana , Sled John G. , Pike G. Bruce 
Published: August 2003

AbstractPurposeTo investigate the dependence of occipital gray and white matter T2 on the Carr‐Purcell‐Meiboom‐Gill (CPMG) refocusing interval, thereby testing the basis of a novel functional magnetic resonance imaging (fMRI) method for blood volume quantification, and addressing recent questions surrounding T2 contrast in the occipital lobe.Materials and MethodsA CPMG sequence with 1 × 1 × 5 mm3 resolution was used to quantify T2 in a single axial slice at the midlevel of the occipital lobe in 23 healthy adult volunteers. Refocusing intervals of 8, 11, and 22 msec were compared. A Bayesian classifier was used to classify a 1 × 1 × 1 mm3 T1‐weighted three‐dimensional data set into gray matter, white matter, and cerebrospinal fluid, with an average 95% a posteriori probability used as the threshold for inclusion into a tissue‐specific region of interest (ROI).ResultsThe usual T2 contrast between the gray and white matter (i.e., T2GM > T2WM) was observed, with a highly significant effect of tissue type on the estimated T2 (P < 10−5). The observed T2 gradually decreased with increasing refocusing interval, for a decrease of 3.3 ± 1.5 msec in gray matter and 3.0 ± 1.5 msec in white matter between the 8 and 22 msec refocusing interval acquisitions.ConclusionThe observed T2 shortening is consistent with the effect of the dramatic decrease in T2 of partly deoxygenated blood on this range of refocusing rates. J. Magn. Reson. Imaging 2003;18:302–309. © 2003 Wiley‐Liss, Inc.
Dynamic contrast enhanced perfusion MRI in mycosis fungoides
Authors: Law Meng , Teicher Noah , Zagzag David , Knopp Edmond A. 
Published: August 2003

AbstractMycosis fungoides is a malignant, cutaneous lymphoma of T‐helper (TH or CD4+) cells. At presentation, the disease is usually limited to the skin, with lesions that resemble eczema or psoriasis. Neurologic involvement is uncommon. This case demonstrates the conventional MRI and dynamic contrast enhanced perfusion MRI findings in intracerebral mycosis fungoides. T1‐weighted spin echo imaging demonstrated a lesion with slightly decreased signal within the body of the corpus callosum. The lesion was isointense with grey matter on axial T2‐weighted imaging. Following administration of contrast, there was patchy heterogeneous enhancement. Multiple relative cerebral blood volume (rCBV) measurements were made and the minimum rCBV was 0.30 with the maximum rCBV being 1.61. The mean rCBV was 0.81 ± 0.49 (average of 10 measurements and standard deviation). J. Magn. Reson. Imaging 2003;18:364–367. © 2003 Wiley‐Liss, Inc.
Enhanced gray and white matter contrast of phase susceptibility‐weighted images in ultra‐high‐field magnetic resonance imaging
Authors: Abduljalil Amir M. , Schmalbrock Petra , Novak Vera , Chakeres Donald W. 
Published: August 2003

AbstractPurposeTo evaluate if magnetic susceptibility sensitive phase postprocessed images can be used to enhance the inherent brain/gray white matter contrast in gradient echo (GE) images at 8‐Tesla (T) magnetic resonance (MR).Materials and MethodsPhase and magnitude images of high‐resolution GE MR 8‐T images were created. Comparisons were made between the magnitude, the product of the magnitude and phase, and pure phase images.ResultsThe pure phase images significantly improved the contrast between the gray and white matter structures. In general, the higher the iron content or subvoxel field inhomogeneities, the higher was the contrast, and the greater were the resultant phase shifts. The phase images best demonstrated anatomy that was not apparent on the standard magnitude images.ConclusionPhase imaging can significantly improve the demonstration of the internal anatomical brain structures over standard magnitude GE imaging techniques at high field. J. Magn. Reson. Imaging 2003;18:284–290. © 2003 Wiley‐Liss, Inc.
Inflow effect in first‐pass cardiac and renal MRI
Authors: Ivancevic Marko K. , Zimine Ivan , Foxall David , Lecoq Guillaume , Righetti Alberto , Didier Dominique , Vallée Jean‐Paul 
Published: August 2003

AbstractPurposeTo estimate the effect of the inflow effect on the arterial input function in vivo in cardiac and renal MR perfusion imaging using fast gradient echo (GRE) sequences and contrast media.Materials and MethodsThe MR exam protocol was designed to acquire images at different phases of the cardiac cycle. The arterial input was thus influenced by various blood flow velocities.ResultsIt was found that the inflow effect was negligible in the left ventricle of the heart, while it was significantly higher in the aorta for the kidney perfusion measurement. This was principally due to the higher through‐the‐plane component of the blood flow velocity in the aorta than in the left ventricle.ConclusionThe inflow effect can be neglected in the heart cavity, but should be taken into account in renal perfusion. J. Magn. Reson. Imaging 2003;18:372–376. © 2003 Wiley‐Liss, Inc.
Fat suppression strategies in enhanced MR imaging of the breast: Comparison of SPIR and water excitation sequences
Authors: Niitsu Mamoru , Tohno Eriko , Itai Yuji 
Published: August 2003

AbstractPurposeTo compare two fat suppression techniques of spectrally‐selective inversion pulse (spectral presaturation with inversion recovery—SPIR) and spectral‐spatial excitation pulse of water excitation (WE) for contrast‐enhanced MR imaging of the breast.Materials and MethodsForty women with histologically‐proven breast cancer were examined. Both pulse types were applied to postcontrast, axial, three‐dimensional field echo sequence. Contrast noise ratios (CNR) of lesion‐to‐breast parenchyma, lesion‐to‐fat, and parenchyma‐to‐fat were determined. Qualitative image analysis using a four‐point scale was also performed by two observers.ResultsAll the CNR values of obtained with WE techniques were significantly higher than those with SPIR. Qualitative analysis indicated that the WE images were statistically superior for the lesion‐to‐breast parenchyma contrast while being slightly inferior to the SPIR images for fat suppression homogeneity without statistical significance.ConclusionCompared to SPIR, the WE technique suppressed the subcutaneous fat signal more potently and improved the contrast of the enhanced breast lesion against the parenchyma and the subcutaneous fat. WE will be a powerful fat suppression strategy for enhanced MR imaging of the breast. J. Magn. Reson. Imaging 2003;18:310–314. © 2003 Wiley‐Liss, Inc.
Three‐dimensional analysis of the geometry of individual multiple sclerosis lesions: Detection of shape changes over time using spherical harmonics
Authors: Goldberg‐Zimring Daniel , Achiron Anat , Guttmann Charles R.G. , Azhari Haim 
Published: August 2003

AbstractPurposeTo suggest a quantitative method for assessing the temporal changes in the geometry of individual multiple sclerosis (MS) lesions in follow‐up studies of MS patients.Materials and MethodsComputer simulated and in vivo magnetic resonance (MR) imaged MS lesions were studied. Ten in vivo MS lesions were identified from sets of axial MR images acquired from a patient scanned consecutively for 24 times during a one‐year period. Each of the lesions was segmented and its three‐dimensional surface approximated using spherical harmonics (SH). From the obtained SH polynomial coefficients, indices of shape were defined, and analysis of the temporal changes in each lesion's geometry throughout the year was performed by determining the mean discrete total variation of the shape indices.ResultsThe results demonstrate that most of the studied lesions undergo notable geometrical changes with time. These changes are not necessarily associated with similar changes in size/volume. Furthermore, it was found that indices corresponding to changes in lesion shape could be 1.4 to 8.0 times higher than those corresponding to changes in the lesion size/volume.ConclusionQuantitative three‐dimensional shape analysis can serve as a new tool for monitoring MS lesion activity and study patterns of MS lesion evolution over time. J. Magn. Reson. Imaging 2003;18:291–301. © 2003 Wiley‐Liss, Inc.