Image-guided localized proton magnetic resonance (MR) spectroscopy of intracranial tumors was performed to correlate spectral patterns and histologic findings. Thirty-six patients were examined prior to any specific treatment. Evaluation based on signal intensity ratios showed that all tumor spectra differed from spectra of healthy brain tissue. Ratios of creatine to choline-containing compounds (Cr/Cho) and nitrogen acetyl-aspartate to Cho (NAA/Cho) were reduced significantly in all tumor spectra compared with spectra of normal tissue in contralateral brain hemispheres (P less than .005). Noncerebral tumors typically showed a vanishing or missing NAA signal, strongly reduced Cr signal, and additional signals, assigned to alanine in meningiomas and lipids in metastases. In contrast, 11 gliomas of grades 2 and 3 exhibited NAA/Cho ratios and Cr/Cho ratios that were less than normal but that were significantly larger (P less than .01) than corresponding values in eight meningiomas. Ten glioblastomas displayed spectra with various signal ratios, so no significant differences between them and other tumor types could be established. In nine gliomas a clearly detectable lactate signal was present. However, no direct correlation between lactate level and histologic tumor grading was found.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1148/radiology.183.3.1584924 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cost-efficient behavioral modeling of antennas by means of global sensitivity analysis and dimensionality reduction.
Sci Rep
January 2025
Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, 80-233, Gdansk, Poland.
Computational tools, particularly electromagnetic (EM) solvers, are now commonplace in antenna design. While ensuring reliability, EM simulations are time-consuming, leading to high costs associated with EM-driven procedures like parametric optimization or statistical design. Various techniques have been developed to address this issue, with surrogate modeling methods garnering particular attention due to their potential advantages.
View Article and Find Full Text PDFData-driven modeling of background radiation structure utilizing matrix profile in nuclear security.
Sci Rep
January 2025
Department of Electrical and Computer Engineering, University of Texas at San Antonio, San Antonio, TX, 78249, USA.
The inherently stochastic nature of radiation emissions makes modeling background radiation structure a particularly challenging research area. In source identification scenarios, which are critical to nuclear security, the complexity of background radiation modeling is intensified by dynamically changing factors that influence radiation measurements. Consequently, accurately modeling and estimating background radiation can significantly improve our nuclear security capabilities by enhancing the detection of anomalies within radiation data.
View Article and Find Full Text PDFPower spectral analysis of voltage-gated channels in neurons.
Front Neuroinform
January 2025
Centre Borelli, Université Paris Cité, UMR 9010, CNRS, Paris, France.
This article develops a fundamental insight into the behavior of neuronal membranes, focusing on their responses to stimuli measured with power spectra in the frequency domain. It explores the use of linear and nonlinear (quadratic sinusoidal analysis) approaches to characterize neuronal function. It further delves into the random theory of internal noise of biological neurons and the use of stochastic Markov models to investigate these fluctuations.
View Article and Find Full Text PDFSources of Microstructure in Mammalian Cochlear Responses.
J Assoc Res Otolaryngol
January 2025
Caruso Department of Otolaryngology-Head & Neck Surgery, University of Southern California, Los Angeles, CA, USA.
Quasiperiodic fluctuations with frequency are observed in a variety of responses that either originate from or strongly depend on the cochlea's active mechanics. These spectral microstructures are unique and stable features of individual ears and have been most thoroughly studied in behavioral hearing thresholds and otoacoustic emissions (OAEs). While the exact morphology of the microstructure patterns may differ across measurement types, the patterns are interrelated and are thought to depend on common mechanisms.
View Article and Find Full Text PDF2D wrinkle assisted zigzag plasmonic chains for isotropic SERS enhancement.
Sci Rep
January 2025
Institute of Physical Chemistry and Polymer Physics, Leibniz-Institut für Polymerforschung Dresden e.V. (IPF), 01069, Dresden, Germany.
Template-assisted colloidal self-assembly has gained significant attention due to its flexibility and versatility. By precisely controlling the shape of the template, it is possible to achieve custom-designed nanoparticle assemblies. However, a major challenge remains in fabricating these templates over large areas at a low cost.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!