Post-Operative Magnetic Resonance Imaging of Canine Cervical Spine After Ventral Slot Surgery; Evaluation of the Porcine-Derived Hemostatic Compound Spongostan™ Specific Imaging Features

Porcine-derived gelatin sponge SPONGOSTAN™ is an adjunct material routinely used in neurosurgery. This study aimed to describe its MRI features, since its imaging features are not available yet in veterinary medicine. Post-operative MR images of dogs that underwent decompressive ventral slot surgery following cervical intervertebral disc extrusion were retrospectively reviewed by three readers; inter-rater association was evaluated using the Spearman’s rank correlation coefficient. Seventy-eight cases were included. In 51% of cases, the hemostatic sponge appeared isointense in T1-W images compared to the semispinalis capitis muscle, and in the remaining 49% of the cases, it appeared iso-hypointense. On T2-W sequences, the material appeared hyperintense in 76% of cases, with signal intensity from hypointense to iso-hyperintense in the remaining 24%. On the GET2-W* sequences, the material appeared hypointense in 91% and iso-hypointense in 9% of cases. A peripheral hyperintense rim was described in 41%, 35% and 6% of T2-W, T1-W and GET2*-W images, respectively. A strong association was detected with a p-value < 0.05 and a correlation between 0.74 and 1. To conclude, based on the findings herein achieved, the association of hyperintensity in T2-W, hypointensity with signal void in GET2*-W images when compared to semispinalis capitis muscle and the presence of a peripheral hyperintense rim can be considered distinctive features for the hemostatic gelatin sponge called SPONGOSTAN™ to correctly identify this hemostatic product in post-operative MRI examinations.