. Author manuscript; available in PMC: 2009 Jul 30.

Published in final edited form as: Magn Reson Med. 2009 May;61(5):1059–1065. doi: 10.1002/mrm.21939

Table 2.

Principle of release monitoring of cargo molecules by MRI/MRS

	Molecular weight / size	Diffusion	MRI signal enhancement	MRS peak
Intact liposome	≈ 120 nm	±	− ^*1	*Broad* ^*2

Released GdDTPA-BMA	≈ 591 Da	+++	+++	N/A
Released 5-FU	130 Da	+++	N/A	*Narrow*
SPIO nanoparticle	40–70 nm	±	− ^*1	N/A ^*2

^*1

T₂ effect of SPIO particles dominates the positive T₁ contrast of GdDTPA, thus intact forms generate strong negative signal enhancement.

^*2

T₂* effect of SPIO broadens 5-FU peak, thus intact forms generate a broad resonance line.