MR features of high-pressure injection injuries caused by grease and paints.

OBJECTIVE

This study investigates the magnetic resonance (MR) features of high-pressure injection injuries (HPII) caused by grease and paints to detect the presence of foreign material and associated complications.

METHODS

Sixteen rat models with HPII were established by injecting industrial grease and marine paints (n = 8 each) into their thighs. All the rats underwent a 3.0 T MR scanning, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), Fat-suppressed T2-weighted imaging (FST2WI), Susceptibility-weighted imaging (SWI), and Diffusion-weighted imaging (DWI). Follow-up MR scanning was performed from 1st to 4th weeks.

RESULTS

Acute subcutaneous grease and paints appeared as different signal intensity characteristics (grease: T1WI ↑, T2WI =, FST2WI ↓, SWI ↓, DWI ↓; paints: T1WI ↑, T2WI ↑, FST2WI ↑↓, SWI ↓, DWI ↓). As time progressed, the signal intensity of HPII lesions caused by both grease and paints became inhomogeneous. Impurity components of the foreign material appeared as marked low signal intensity on SWI. The signal intensity on DWI significantly increased subsequently due to purulent fluids (confirmed surgically).

CONCLUSIONS

HPII caused by grease and paints have a characteristic appearance on MR imaging. SWI can detect impurity components of the foreign material, while DWI is highly sensitive to abscesses and helpful in monitoring infections.