Improving MRI contrast: Contrast agents
Learning objectives
After reading this chapter, you should be able to:
- Present the different fat signal suppression techniques
- Describe the advantages and disadvantages of STIR sequences, fat saturation, selective excitation of water
- Specify the different families of contrast agents
- Explain their action on relaxation time and contrast
- List their contraindications and main indications
- Explain magnetization transfer and how it can improve background suppression
Key points
Contrast agents
Contrast agent | Principles | Advantages / Applications | Contraindications / Adverse effects |
Gadolinium chelates | T1 reduction +++ T2 reduction | Enhanced T1-weighted signal Perfusion imaging Well tolerated | Allergy, pregnancy Renal/liver failure: Nephrogenic systemic fibrosis |
SPIO | Superparamagnetic iron oxides: T2* effect | SPIO: liver USPIO: ganglion | |
Manganese chelates | T1 effet | Liver and biliary imaging |
References
- Elster. Questions and answers in magnetic resonance imaging. 1994:ix, 278 p.
- McRobbie. MRI from picture to proton. 2003:xi, 359 p.
- NessAiver. All you really need to know about MRI physics. 1997.
- Kastler. Comprendre l'IRM. 2006.
- de Kerviler, Leroy-Willig. Fat suppression techniques in MRI: an update. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 1998;52(2):69-75.
- Gandhi, Brown. MR contrast agents for liver imaging: what, when, how. Radiographics. 2006 Nov-Dec;26(6):1621-36.
- Lin and Brown. MR contrast agents: Physical and pharmacologic basics. J Magn Reson Imaging. 2007 May;25(5):884-99.
- Sadowski, Bennett. Nephrogenic Systemic Fibrosis: Risk Factors and Incidence Estimation. Radiology. 2007 Jan 31.