Evaluation of hyperacute cerebral ischemia in rats using micro SPECT/CT / 中华核医学与分子影像杂志

ABSTRACT

Objective To assess the diagnostic value of 99Tcm-ECD SPECT for hyperacute cerebral ischemia using rats models.Methods A stable and permanent acute cerebral ischemia model using unilateral middle cerebral occlusion was tested in 24 healthy SD rats.The rats were randomly divided into 6 groups according to the time duration between imaging and induced-ischemia (1,2,3,4,5 and 6 h,respectively).The rats were sacrificed immediately after 99Tcm-ECD SPECT/CT imaging and then the brain tissue was dissected for triphenyl tetrazolium chloride (TTC) and HE staining.The count ratio of affected cortex to the contralateral cortex of ＜ 50％ was defined as ischemia on micro SPECT/CT.The volume of the ischemic area was calculated on both SPECT/CT and TTC images.Paired t test was used to determine the statistical difference between the volumes on SPECT/CT and TTC staining.Results The ischemia volume evaluated by TTC staining at 1,2,3,4,5 and 6 h after occlusion was (73.98 ± 27.76),(90.75 ±29.00),(135.00±40.83),(136.25±22.51),(158.50±32.72) and (168.00±32.75) mm3,respectively.The corresponding ischemia volume evaluated by micro SPECT/CT was (98.50 ± 27.77),(110.40±26.80),(157.00±36.82),(165.50±26.54),(175.75±31.16) and (177.25 ±34.33) mm3,respectively,which was concordant with that by TTC staining at each time point (t-1.681 to-0.390,all P ＞0.05).The ischemic area on micro SPECT/CT imaging was consistent with the pink area by TTC staining.The volume evaluated by micro SPECT/CT tended to be constant 3 h after the occlusion.The ischemia volume showed no significant difference among 3,4,5 and 6 h (all P ＞ 0.05).Conclusions Micro SPECT/CT may have an haemodynamic value for evaluating in vivo cerebral ischemia applied in a rat model.It might have clinical value for the evaluation and decision-making of ultra acute cerebral infarctions.