TABLE 1.

The Size, Organ/Tissue Enhancement, Biomarker Recognition, Relaxivity, and Dosages of Typical MRI Contrast Agents

Targeting or Not	Contrast Agents	Size	Organ/Tissue Enhancement	Biomarker Recognition	Per Gd3+, r1, mM–1 s–1	Field Strength, T	Temperature, °C	Dosage, μmol Gd/kg	References
Nontargeted contrast agents	Gd-DTPA	547 Da	Whole body, brain, CNS, kidney	None	3.5	1.5	20	100–200	71
	MS-325		Blood vessel	None	42	0.47	37	30	44, 72
	Gadomer-17	35 kDa	Blood vessel	None	17.3	0.47	40	25–100	73
	PAMAM-G4	59 kDa	Liver, kidney, blood vessel	None	29	1.5	20	30	15, 45
	NanoglobularMRI CAs (G3)	3.2 nm	Blood vessel, tumor, vasculature	None	10	3	RT	10–30	74
		27 kDa
	Gold nanoparticles	1.9 nm	Kidney, bladder	None	4.1	7	RT	[Gd3+] 5 mM, 300 μl	75
ProCA	ProCA1, ProCA1.affi, ProCA1.GRP	12 kDa	Kidney, liver, and tumor biomarkers	Nontarget, HER-2, GRPR	117	1.4	RT	2.4	64
		2–3 nm
Targeted contrast agents	EP-3533		Collagen-rich scar, collagen-rich liver	Collagen	18.7	0.47	37	25 μmol particle/kg, 20 μmol particle /kg	76, 77
	EP-3600		Myocardium	Collagen	21.3	1.4	37	12.3 μmol particle/kg	78
	Gd-DOTA-R832		Inflammation lesions in liver	VCAM-1	8.5	0.47	37	100	79
	Peptoid-(Gd)8-dendron	~8.6 kDa	Tumor	VEFGR2	13.8	0.54	37	8 μmol particle /kg, 32 μmol Gd/kg	80
	αvβ3-Integrin-targeted nanoparticles	270 nm	Tumor	αvβ3-integrin	20 (1,800,000)	0.47	40		81
		167 and 236 nm	Tumor	αvβ3-integrin				2 mL/kg, 0.2 nM	82
		273 nm	Tumor	integrin	19.1	0.47	37	3	83
					0.47 T
		273 nm	Angiogenesis in atherosclerosis	αvβ3-integrin	17.7	1.5		0.5 mL/kg	84
	bG4D-Gd-SA	4182 Da	Her-2 positive tumor	HER2 by multiple step				145	70
	Gd-perfluorocarbon nanoparticles	<250 nm	Vulnerable plaques	Fibrin	18			0.25–0.5 mL/kg	24
	Dendrimer nanoclusters	75–150 nm	Subcutaneous tumor xenografts	Folate receptor	12.3	1.4	40	300	22
	P947		Atherosclerotic plaques	MMPs, ACE, and APN					85

CNS, central nervous system; MRI CA, magnetic resonance imaging contrast agents; GRP, gastrin-releasing peptide; GRPR, gastrin-releasing peptide receptor; MMP, matrix metalloproteinases; ACE, angiotensin-converting enzyme; APN, aminopeptidases N