Search results for " Magnetic resonance"
showing 10 items of 2317 documents
Design and evaluation of a 32-channel phased-array coil for lung imaging with hyperpolarized 3-helium
2010
Imaging with hyperpolarized 3-helium is becoming an increasingly important technique for MRI diagnostics of the lung but is hampered by long breath holds (>20 sec), which are not always applicable in patients with severe lung disease like chronic obstructive pulmonary disease (COPD) or α-1-anti-trypsin deficiency. Additionally, oxygen-induced depolarization decay during the long breath holds complicates interpretation of functional data such as apparent diffusion coefficients. To address these issues, we describe and validate a 1.5-T, 32-channel array coil for accelerated 3He lung imaging and demonstrate its ability to speed up imaging 3He. A signal-to-noise ratio increase of up to a factor…
Stronger proprioceptive BOLD-responses in the somatosensory cortices reflect worse sensorimotor function in adolescents with and without cerebral pal…
2020
Graphical abstract
Imaging of calcified hepatic lesions: spectrum of diseases
2021
Hepatic calcifications have been increasingly identified over the past decade due to the widespread use of high-resolution Computed Tomography (CT) imaging. Calcifications can be seen in a vast spectrum of common and uncommon diseases, from benign to malignant, including cystic lesions, solid neoplastic masses, and inflammatory focal lesions. The purpose of this paper is to present an updated review of CT imaging findings of a wide range of calcified hepatic focal lesions, which can help radiologists to narrow the differential diagnosis.
Temozolomide and radiotherapy antitumor efficacy evaluation with magnetic resonance imaging and proton magnetic resonance spectroscopy in human gliom…
2008
International audience
Reinvestigation of the synthesis and evaluation of [N-methyl-11C]vorozole, a radiotracer targeting cytochrome P450 aromatase
2009
Abstract Introduction We reinvestigated the synthesis of [ N -methyl- 11 C]vorozole, a radiotracer for aromatase, and discovered the presence of an N -methyl isomer which was not removed in the original purification method. Herein we report the preparation and positron emission tomography (PET) studies of pure [ N -methyl- 11 C]vorozole. Methods Norvorozole was alkylated with [ 11 C]methyl iodide as previously described and also with unlabeled methyl iodide. A high-performance liquid chromatography (HPLC) method was developed to separate the regioisomers. Nuclear magnetic resonance (NMR) spectroscopy ( 13 C and 2D-nuclear Overhauser effect spectroscopy NMR) was used to identify and assign s…
Glutathione conjugation of trans-3,4-dihydroxy 1,2-epoxy l,2,3,4-tetrahydrobenzo[c]phenanthrene isomers by human glutathione transferases
1992
Each of the four stereoisomers of trans-3,4-dihydroxy 1,2-epoxy 1,2,3,4-tetrahydrobenzo[c]phenanthrene [(+)- and (-)-anti-BPhDE and (+)- and (-)-syn-BPhDE] has been incubated with the human glutathione transferase (GST) isoenzymes GST A1-1, GST M1-1 and GST P1-1, representing class alpha, mu and pi respectively, and glutathione (GSH). The conjugates formed were analyzed by HPLC and the results demonstrate that all GST isoenzymes catalyze the formation of GSH conjugates of all BPhDE isomers. However, a marked variation in catalytic efficiencies was observed (0.122-1.28/mM/s). These values are considerably lower than those previously estimated for the bay-region diol epoxides of benzo[a]pyren…
Accelerated T2-Weighted TSE Imaging of the Prostate Using Deep Learning Image Reconstruction: A Prospective Comparison with Standard T2-Weighted TSE …
2021
Multiparametric MRI (mpMRI) of the prostate has become the standard of care in prostate cancer evaluation. Recently, deep learning image reconstruction (DLR) methods have been introduced with promising results regarding scan acceleration. Therefore, the aim of this study was to investigate the impact of deep learning image reconstruction (DLR) in a shortened acquisition process of T2-weighted TSE imaging, regarding the image quality and diagnostic confidence, as well as PI-RADS and T2 scoring, as compared to standard T2 TSE imaging. Sixty patients undergoing 3T mpMRI for the evaluation of prostate cancer were prospectively enrolled in this institutional review board-approved study between O…
Whole-body magnetic resonance imaging in the diagnosis and follow-up of multicentric infantile myofibromatosis: A case report
2017
Myofibromatosis is an uncommon disorder of infancy, characterized by proliferation of myofibroblasts in solitary or multiple nodules. The clinical characteristics depend on the involved sites: Myofibromatosis may develop as a musculoskeletal form, with non-painful swellings and eventual mass effect symptoms, or as a generalized form with visceral involvement and organ failure. Prognosis and therapy vary between the abovementioned patterns. When there is no visceral involvement, the tumors may regress spontaneously; however, the visceral form may represent a lifethreatening condition with poor outcome and it requires aggressive management. Imaging assessment of disease spread is mandatory to…
MR-based biomarkers in the diagnosis and the evaluation of the therapeutic response to radiotherapy (ETRR) in prostatic carcinoma (PCa): Implementati…
2009
e16136 Background: ETRR in PCa remains a challenging task. New biomarkers in the form of metabolites, detected with Proton Magnetic Resonance Spectroscopy (1H-MRS), and quantitative Apparent Diffusion Coefficient (ADC), determined with Diffusion-Weighted Magnetic Resonance Imaging, could be of value in the ETRR for PCa. Methods: Twenty-one men with biopsy proven localized PCa were examined before external radiotherapy. 3D-1H-MRS was performed at 3.0T without endorectal coils. The delivered radiotherapy dose was 78 Gy in 39 fractions with 6 MV photons. MR follow-up examinations up to 36 months post-radiotherapy were performed. For the pre-clinical study, healthy rat prostate was studied in …
Cavitation of electron bubbles in liquid parahydrogen
2011
Within a finite-temperature density functional approach, we have investigated the structure of electron bubbles in liquid parahydrogen below the saturated vapour pressure, determining the critical pressure at which electron bubbles explode as a function of temperature. The electron-parahydrogen interaction has been modelled by a Hartree-type local potential fitted to the experimental value of the conduction band-edge for a delocalized electron in pH(2). We have found that the pressure for bubble explosion is, in absolute value, about a factor of two smaller than that of the homogeneous cavitation pressure in the liquid. Comparison with the results obtained within the capillary model shows t…