title: New surgical technique reduces the susceptibility artefact at air-tissue interfaces on in vivo cerebral MRI in the Göttingen minipig.
abstract: Advanced and exclusive software solutions are offered to reduce susceptibility artefacts on MRI echo-planar sequences. We present a straightforward surgical technique to reduce the cortical distortion and signal loss that normally occur using diffusion tensor imaging (DTI) of the Göttingen minipig brain. Pronounced pneumatisation of the minipig cranium causes considerable susceptibility artefacts at the air/tissue interface around the frontal sinuses. Five Göttingen minipigs had burr holes drilled through the outer lamina of the skull bilaterally at the level of bregma. The underlying frontal sinuses were filled with a suspension of an MRI-compatible alginate. DTI was obtained before and after placing the medium in the sinus, quantifying the change using mutual information and Wilcoxon's rank-sum test. Fibertracking algorithms were applied to visualize the effect of treatment. We showed that the susceptibility artefacts were reduced at the air, bone and brain interfaces and that major cortical fiberbundles could be reliably visualized. This study demonstrated that DTI fibertracking of cortical bundles in experimental animals with extensive skull pneumatisation is feasible even when advanced software is unavailable.
authors.affiliation: Center for Experimental Neuroscience (CENSE), Department of Neurosurgery, University Hospital of Aarhus, DK-8000 Aarhus C, Denmark. frosendal@hotmail.com
authors.forename: Frederikke
authors.initials: F
authors.lastname: Rosendal
authors.forename: Jesper
authors.initials: J
authors.lastname: Frandsen
authors.forename: M Mallar
authors.initials: MM
authors.lastname: Chakravarty
authors.forename: Carsten Reidies
authors.initials: CR
authors.lastname: Bjarkam
authors.forename: Michael
authors.initials: M
authors.lastname: Pedersen
authors.forename: Ryan
authors.initials: R
authors.lastname: Sangill
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Sørensen
mesh_terms: D000388:Air; D000464:Alginates; D000465:Algorithms; D000818:Animals; D016477:Artifacts; D001921:Brain / Q000473:pathology*; D003287:Contrast Media; D003399:Craniotomy / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005626:Frontal Sinus / Q000473:pathology / Q000601:surgery; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D007091:Image Processing, Computer-Assisted; D007257:Information Theory; D008279:Magnetic Resonance Imaging / Q000379:methods; D012886:Skull / Q000473:pathology / Q000601:surgery*; D013552:Swine; D013556:Swine, Miniature
chemical_list: D000464:Alginates; D003287:Contrast Media; D006603:Hexuronic Acids; D020723:Glucuronic Acid