Positive Contrast Imaging of SPIO Nanoparticles

Table 1

Advantages and disadvantages of the currently used positive contrast imaging methods with SPIO nanoparticles.

	Perturbation of magnetic field gradient based methods		Proton precession frequency based methods				Phase (postprocessing) based methods
	GRASP	iDQC	SR-SPSP	ORS	IRON	SSFP	PSM	SWI	SGM/PGM
Effective and sensitive	Fair	Low	Fair	Fair	Fair	Fair	High	High	High
Sensitivity to field inhomogeneity	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Sensitivity to susceptibility gradients	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Suppression of background signal	Poor	Good	Fair	Fair	Fair	Fair	Poor	Fair	Fair
Suppression of water signal	Poor	Good	Good	Good	Fair	Good	Poor	Fair	Fair
Signal-to-noise ratio	Fair	Low	High	High	High	High	Fair	Fair	High
Intrinsic drawback	Low sensitivity in high field	Require long TE	Two acquisitions required	Spurious signals from field inhomogeneity