Thomas Kampf1, Christian Herbert Ziener1,
Peter Michael Jakob1,2, Wolfgang Rudolf Bauer3
1Experimental Physics 5, University of
Wuerzburg, Wuerzburg, Bavaria, Germany; 2Research Center for
Magnetic Resonance Bavaria (MRB), Wuerzburg, Bavaria, Germany; 3Medical
Clinic and Polyclinic 1, University of Wuerzburg, Wuerzburg, Bavaria, Germany
Contrast
agents (CA) are commonly used to alter the contrast in MR data. Thus,
profound knowledge of the CAs influence on the MR signal is important. In
this work the effect of CA internalization is studied numerically. The
simulations show that the simple linear relationship between the
concentration of the CA and the relaxation rate is not preserved if the CA is internalized in a small part
of the volume. This leads to a decreased apparent relaxivity. Furthermore an
upper limit for the averaged relaxation rate was observed for a given volume
fraction and size of the CA containing compartment.