Molecular Magnetic Resonance Imaging with Contrast Agents for Assessment of Inflammatory Bowel Disease: A Systematic Review

Table 2

The applications of molecular contrast agents MRI in IBD-related model.

NPs	Material	Field strength	Sequences	Enhancement^a	Administration	Procedures
MNPs	Ferumoxides [9]	9.4 T	T1WI	Intestinal wall T1WI (↓)	iv	Long enhancement sustained time, quantitative analysis
	SHU 555C [10]	2.4 T	T1WI, T2WI, T2	Mucosa T1WI (↑), deep colon wall T1WI (↓) &T2WI (↓)	iv	Quantitative analysis
	Nanotex [11]	7 T	T1WI	Colon wall T1WI (↓)	iv	Integration of diagnosis and treatment
	CN-ICG-IO [12]	3 T	T2WI	NA^b	po	Oral administration, potential to monitor inflammation and targeted delivery
Gd-related NPs	Gd-FITC-SLN [13]	3.0 T	T1WI	Focal lesion; T1WI (↑)	pr	Targeted imaging through intestinal absorption, low Gd deposition, quickly metabolized
	Gd in chitosan nanoparticles [14]	3.0 T	T1W	Mucosa T1WI (↑)^b	pr	Targeted imaging through intestinal absorption, low Gd deposition
	PEG-coated Gd in PBNPs [15]	1.5 T	T1WI	NA^b	po	Potential to monitor inflammation or targeted delivery, low Gd deposition, oral administration
PFC	PFC emulsion [16]	11.7 T	T1WI	Special^19F signal in focal lesion	iv	Quantitative analysis; not affected by bowel movements or the existence of air pocket

CN-ICG-IO, casein-coated indocyanine green-loaded iron oxide nanoparticle; FITC, fluorescein isothiocyanate; Gd, gadolinium; iv, intravenously; MNPs, magnetic nanoparticles; NA, not available; NPs, nanoparticles; PBNPs, Prussian blue nanoparticles; PEG, polyethylene glycol; PFC, perfluorocarbon; po, per os; pr, per rectum; T1WI, T1-weighted image; T2WI, T2-weighted image. Notes: ^aMNPs have both T1W and T2W effect, and these show the major effect with suitable dose in corresponding experiments; ^bhealthy animals were used in the experiment; (↑) signal increased; (↓) signal decreased.