High Relaxivity Contrast Agents for MRI and Molecular Imaging

  • S. Aime
  • A. Barge
  • E. Gianolio
  • R. Pagliarin
  • L Silengo
  • L Tei
Part of the Ernst Schering Research Foundation Workshop book series (SCHERING FOUND, volume 49)

6.5 Concluding Remarks

Gd(III) chelates have played an important role in the development of clinical applications of MRI technique by adding relevant physiological information to the superb anatomical resolution attainable with this imaging modality.

More is still expected with the currently available contrast agents, especially in the field of dynamic contrast enhancement protocols reporting on changes of the vascular permeability associated with the staging and therapeutic follow-up of important pathologies. However, the major challenges are in the emerging field of molecular imaging where the competition with other imaging modalities can be very tight. Targeting of thrombi and atherosclerotic plaques by peptides functionalized with Gd(III) chelates appears to be the next goal for industrial research. The possibility of identifying and characterizing vulnerable plaques will certainly represent an important task. Clearly, there is a need for new ideas for enhancing the attainable relaxivity at higher fields as the 3-T indication for clinical imagers seems to be quite established. Moreover, it will be necessary to improve the efficiency of the available delivery systems and, possibly, to exploit suitable amplification procedures in order to reach the sensitivity required for the visualization of target molecules present at low concentrations.

The results herein surveyed show that there are several routes for cell entrapment of paramagnetic Gd-agents at concentrations sufficient for MRI visualization. The huge work carried out in a number of laboratories in the last two decades for the development of Gd-based MRI contrast agents provides an excellent platform for designing a new generation of probes for molecular imaging applications. Though one should not underestimate the difficulties that will arise when going from in vitro experiments to in vivo animal studies, we think that the available results suggest that Gd-chelates will have an important role in the armory of imaging probes for cellular and molecular imaging applications.


Contrast Agent Magnetic Resonance Imaging Contrast Agent Relaxation Enhancement Water Exchange Rate Exchange Lifetime 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • S. Aime
    • 1
  • A. Barge
    • 1
  • E. Gianolio
    • 1
  • R. Pagliarin
    • 2
  • L Silengo
    • 3
  • L Tei
    • 4
  1. 1.Dipartimento di Chimica I.F.M. e Centro per il Molecular ImagingUniversità di TorinoTurinItaly
  2. 2.Dipartimento di Chimica Organica e IndustrialeUniversità di MilanoMilanItaly
  3. 3.Dipartimento di Genetica, Biologia e BiochimicaUniversità di TorinoTurinItaly
  4. 4.Dipartimento di Medicina InternaUniversità di TorinoTurinItaly

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