Abstract
Fast field-cycling (FFC) MRI allows switching of the magnetic field during an imaging scan. FFC-MRI takes advantage of the T(1) dispersion properties of contrast agents to improve contrast, thus enabling more sensitive detection of the agent. A new contrast agent designed specifically for use with FFC was imaged using both a homebuilt FFC-MRI system and a 3 T Philips clinical MRI scanner. T(1) dispersion curves were obtained using a commercial relaxometer which showed large changes in relaxation rate between fields. A model of magnetization behaviour was used to predict optimum evolution times for the maximum T(1) contrast between samples at each field. Images were processed and analysed to create maps of R(1) values using a set of images at each field. The R(1) maps produced at two different fields were then subtracted from each other in order to create a map of ¿R(1) in which pixel values depend on the change in R(1) of the sample between the two fields. The dispersion properties of the agent resulted in higher contrast in a ¿R(1) image compared with a standard T(1)-weighted image.
Original language | English |
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Pages (from-to) | 105-115 |
Number of pages | 11 |
Journal | Physics in Medicine and Biology |
Volume | 56 |
Issue number | 1 |
Early online date | 30 Nov 2010 |
DOIs | |
Publication status | Published - 7 Jan 2011 |
Keywords
- algorithms
- animals
- chlorides
- contrast media
- heterocyclic compounds
- liposomes
- magnetic resonance imaging
- manganese compounds
- organometallic compounds
- phantoms, imaging
- reproducibility of results
- sensitivity and specificity
- time factors