A Brief Review of Edema-Adjusted Infarct Volume Measurement Techniques for Rodent Focal Cerebral Ischemia Models with Practical Recommendations

Abstract

Background—Determining cerebral infarction volume is an important part of preclinical studies to deter‐
mine the benefit of potential therapies on stroke outcome. A well-known problem in determining the actual
infarction volume of rodent models is the presence of edema. Because of this, algorithms must be utilized
to obtain the edema-adjusted (EA)-infarct volume. Different methods based on 2,3,5-triphenyltetrazolium
hydrochloride (TTC) staining have been published describing algorithms to determine the EA-infarct vol‐
ume.
Materials and Methods—Simulated models of infarction and corresponding swelling were employed to
determine which absolute method of calculation (Lin et al., Reglodi et al., or Belayev et al.) is the most
accurate in calculating the absolute EA-infarct volume.
Results—The Reglodi and Belayev methods were statistically more accurate in measuring EA-infarct vol‐
ume than Lin’s method, p = 0.0078. Though there was no significant difference between Reglodi’s and
Belayev’s methods for the EA-infarction volume calculation, Reglodi’s approach was closer to the groundtruth infarct volume while also being simpler and more straightforward to use.
Conclusion—We recommend that Reglodi’s method, that is EA-infarct volume = infarct volume × (con‐
tralateral hemisphere/ipsilateral hemisphere), to be used in calculating EA-infarct volume in TTC stained
rodent brains. Further, factors such as inhomogeneous infarction distribution in a given brain slice can also
contribute to the error in volume calculation. Therefore, the average of the infarct area obtained from ante‐
rior and posterior views of a given slice should be used to account for the variation. Considering different
factors, we have provided a summary recommendation for calculating the infarction volume.