Figure 4.

The in vivo MRI of severe AP models in SD rats.

Notes: After the severe AP model in SD rats was established, the rats were injected with M-Gd-NL, Gd-NL, or Gd-DTPA via the tail veins (0.1 mmol/kg Gd-DTPA, 5 rats per group). MRI was obtained at a 3.0T unit (Magnetom Verio, Siemens Healthcare) using a 32-channel wrist coil. (A) The T₁ images of severe AP model were obtained at four time points (before treatment: pre-contrast; 5 min after injection: post 5 min; 60 min after injection: post 60 min; 120 min after injection: post 120 min) by turbo spin echo sequence. The ROIs, manually drawn in the pancreas images (red dotted lines), were used to determine the signal intensity of the pancreases after injection of the contrast agent. (B) For quantitative analysis, the T₁WI signal-to-noise ratio of the ROIs was used to determine the signal intensity of severe AP after injection of each contrast agent. All comparisons were performed between the two groups by one-way ANOVA with Newman–Keuls posttest. Data are expressed as mean ± standard deviation (n=5). *P<0.05; **P<0.01.

Abbreviations: Gd-DTPA, gadolinium-diethylenetriaminepentaacetic; Gd-NL, Gd-DTPA-loaded liposomes; M-Gd-NL, gadolinium-diethylenetriaminepentaacetic-loaded mannosylated liposomes; AP, acute pancreatitis; MRI, magnetic resonance imaging; ROIs, regions of interests; SD, Sprague Dawley; T₁WI, T₁-weighted.