Characteristics of wooden intraocular foreign body by magnetic resonance imaging in rabbits

OBJECTIVE: Intraocular foreign body (IOFB), a frequent cause of ocular trauma, causes serious damage to the eyes. This study was designed to elaborate and compare the characteristics of different magnetic resonance imaging (MRI) sequences in detecting wooden IOFBs in rabbits. METHODS: The right vitreous of 24 healthy rabbits was randomly implanted with diverse wooden foreign bodies (diameter φ = 0.2 mm). The T(1)-weighted imaging (T(1)WI), T(2)-weighted imaging (T(2)WI), proton density-weighted imaging (PDWI), and susceptibility-weighted imaging (SWI) sequences were applied individually 2 weeks after the implantation. RESULTS: IOFBs were detected as linear low signals on T(1)WI, T(2)WI, PDWI, and SWI (SWI image). The detectable rates of poplar wood with a length of 0.5 mm were 0%, 50%, 0%, and 67% for T(1)WI, T(2)WI, PDWI, and SWI, respectively. SWI and T(2)WI sequences exhibited higher sensitivity than T(1)WI and PDWI. The detectable rates of the first three SWI sequences (magnitude, phase, and SWI) were all 67%, which was higher than that of the minimum intensity projection sequence (33%). CONCLUSION: MRI is practicable in the diagnosis of wooden IOFBs. SWI and T(2)WI are optimal for the integrated diagnosis of wooden IOFBs and could be used for diagnosis and immediate treatment.