Extended ISIS sequences insensitive to T(1) smearing.

Magn Reson Med

Department of Radiation Physics, Göteborg University, Sahlgrenska University Hospital, Göteborg, Sweden.

Published: October 2000

Image selected in vivo spectroscopy (ISIS) is a volume selection method often used for in vivo (31)P MRS, since it is suitable for measurements of substances with short T(2). However, ISIS can suffer from significant signal contributions caused by T(1) smearing from regions outside the VOI. A computer model was developed to simulate this contamination. The simulation results for the ISIS experiment order implemented in our MR system (ISIS-0) were in agreement with results obtained from phantom measurements. A new extended ISIS experiment order (E-ISIS) was developed, consisting of four "optimal" ISIS experiment orders (ISIS-1 to ISIS-4) performed consecutively with dummy ISIS experiments in between. The simulation results show that contamination due to T(1) smearing is, effectively, eliminated with E-ISIS and is significantly lower than for ISIS-0 and ISIS-1. E-ISIS offers increased accuracy for quantitative and qualitative determination of substances studied using in vivo MRS. Hence, E-ISIS can be valuable for both clinical and research applications.

Download full-text PDF

Source
http://dx.doi.org/10.1002/1522-2594(200010)44:4<546::aid-mrm8>3.0.co;2-7DOI Listing

Publication Analysis

Top Keywords

isis experiment
12
extended isis
8
experiment order
8
isis
6
isis sequences
4
sequences insensitive
4
insensitive smearing
4
smearing image
4
image selected
4
selected vivo
4

Similar Publications

Phenomenological Modeling of Antibody Response from Vaccine Strain Composition.

Antibodies (Basel)

January 2025

Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.

The elicitation of broadly neutralizing antibodies (bnAbs) is a major goal of vaccine design for highly mutable pathogens, such as influenza, HIV, and coronavirus. Although many rational vaccine design strategies for eliciting bnAbs have been devised, their efficacies need to be evaluated in preclinical animal models and in clinical trials. To improve outcomes for such vaccines, it would be useful to develop methods that can predict vaccine efficacies against arbitrary pathogen variants.

View Article and Find Full Text PDF

Protecting monoclonal antibodies via competitive interfacial adsorption of nonionic surfactants.

J Colloid Interface Sci

December 2024

Biological Physics Laboratory, Department of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK. Electronic address:

Hypothesis: Bioengineered monoclonal antibodies (mAbs) have gained significant recognition as medical therapies. However, during processing, storage and use, mAbs are susceptible to interfacial adsorption and desorption, leading to structural deformation and aggregation, and undermining their bioactivity. To suppress antibody surface adsorption, nonionic surfactants are commonly used in formulation.

View Article and Find Full Text PDF

Hypothesis: Nanoscale characterisation of the self-associated species formed by amphiphilic pharmaceuticals in aqueous solution carries relevance across their entire journey from development through to manufacture - relevant, therefore, not only as regards formulation of the drug products as medicines, but also potentially relevant to their bioavailability, activity, and clinical side effects. Such knowledge and understanding, however, can only be fully secured by applying a range of experimental and theoretical methodologies.

Experiments: Herein, we apply a synergistic combination of solubility, surface tension, SANS, NMR and UV spectroscopic studies, together with MD simulation and QM calculations, to investigate the meso-structures of propranolol hydrochloride aggregates in bulk aqueous solutions, at concentrations spanning 2.

View Article and Find Full Text PDF

Quasi-One-Dimensional Spin Dynamics in a Molecular Spin Liquid System.

Phys Rev Lett

December 2024

RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan.

The molecular triangular lattice system, β^{'}-EtMe_{3}Sb[Pd(dmit)_{2}]_{2}, is considered as a candidate material for the quantum spin liquid state, although ongoing debates arise from recent controversial results. Here, the results of electron spin resonance and muon-spin relaxation measurements on β^{'}-EtMe_{3}Sb[Pd(dmit)_{2}]_{2} are presented. Both results indicate characteristic behaviors related to quasi-one-dimensional spin dynamics, whereas the direction of anisotropy found in electron spin resonance is in contradiction with previous theories.

View Article and Find Full Text PDF

ABX-type hybrid organic-inorganic structures have recently emerged as a new class of meltable materials. Here, by the use of phenylphosphonium derivatives as A cation, we study liquid- and glass-forming behavior of a new family of hybrid structures, (RPhP)[Mn(dca)] (R = Me, Et, Ph; dca = dicyanamide). These new compounds melt at 196-237 °C () and then vitrify upon cooling to room temperature, forming glasses.

View Article and Find Full Text PDF

Want 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!