Abstract
The theoretical equations for paramagnetic contrast agent effects and the spin echo pulse sequence are combined to graph magnetic resonance (MR) intensity as a function of paramagnetic contrast agent concentration for various tissues. Analysis of the graphs and equations demonstrate several technical and clinical implications. These include: (1) positive enhancement is most likely to occur with short TEs and TRs; (2) changes in machine parameters TE and TR will change the concentration of agent at which the peak enhancing MR intensity will occur; (3) there is an absolute max-ium MR intensity that can be reached with contrast enhancement; (4) the maximum MR intensity reached with enhancement is dependent on the tissues’ T2 and, to a lesser degree, T1 relaxation times; (5) certain TE and TR combinations will cause no enhancement; (6) if positive enhancement does occur, it will usually occur only over a limited range of agent concentration; and (7) the tissues’ T1 relaxation time but not its T2 time determines whether positive enhancement will occur and the relative amount of enhancement.
Original language | English (US) |
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Pages (from-to) | 381-388 |
Number of pages | 8 |
Journal | Investigative radiology |
Volume | 23 |
Issue number | 5 |
DOIs | |
State | Published - May 1988 |
Externally published | Yes |
Keywords
- Contrast enhancement
- Contrast media
- Magnetic resonance imaging
- Nuclear magnetic resonance
- Paramagnetic agents
- Spin echo
ASJC Scopus subject areas
- General Medicine