Preparation of fixed mouse brains for MRI.
In fixed mouse brain magnetic resonance images, a high prevalence of fixation artifacts have been observed. Of more than 1700 images of fixed brains acquired at our laboratory, fixation artifacts were present in approximately 30%. In this study, two of these artifacts are described and their causes are identified. A hyperintense rim around the brain is observed when using perfusates reconstituted from powder and delivered at a high flow rate. It is proposed that these perfusion conditions cause blockage of the capillary beds and an increase in pressure that ruptures the vessels, resulting in a blister of liquid below the dura mater. Secondly, gray-white matter contrast inversion is observed when too short a fixation time or too low a concentration of fixative is used, resulting in inadequate fixation. The deleterious consequences of these artifacts for quantitative data analysis are discussed, and precautions for their prevention are provided.
Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada. lcahill@phenogenomics.ca
Lindsay S
LS
Cahill
Christine L
CL
Laliberté
Jacob
J
Ellegood
Shoshana
S
Spring
Jacqueline A
JA
Gleave
Matthijs C van
MC
Eede
Jason P
JP
Lerch
R Mark
RM
Henkelman
D000818:Animals; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D051379:Mice; D008810:Mice, Inbred C57BL; D016707:Tissue Fixation / Q000379:methods*