Abstract: Objective · To detect and evaluate the hypothalamic infarction in middle cerebral artery occlusion (MCAO) model rat. Methods · For 15 Sprague-Dawley rats weighed 200–250 g, aged 6–8 months, their right middle cerebral artery was occluded for 90 mina silicon-coated 4–0 nylon filament and reperfused. Sprague-Dawley rats underwent diffusion weighted MR imaging (DWI) scanning (at 1 h and 24 h after reperfusion) and 2, 3, 5-triphenyl tetrazolium chloride (TTC) staining (at 24 h after reperfusion) to determine the hypothalamic and cerebral infarct volume. The relationship between hypothalamic infarct volume and cerebral infarction volume was analyzedDWI scanning. The results of TTC staining were compared with those of 24 h DWI scanning. Results · Fifteen Sprague-Dawley rats successfully received intraluminal MCAO/reperfusion procedures. The incidences of hypothalamic infarction on brain DWI scanning and TTC staining were 100% and 40% at 24 h after reperfusion, respectively. Therefore, DWI scanning was more sensitive than TTC staining to detect hypothalamic injury (P0.001). The hypothalamic infarct volume on DWI scanning was (8.59±2.89) mm3 and (11.65±3.19) mm3 at 1 h and 24 h after reperfusion, respectively. On DWI scanning, hypothalamic and cerebral infarct volume at 24 h after reperfusion were correlated with each other significantly (r0.573, P0.025), so were the increases of hypothalamic and cerebral infarct volume (r0.554, P0.032) 1 h to 24 h. Conclusion · DWI scanning was more sensitive thanTTC staining todetect hypothalamic injury in intraluminal transient MCAO model. Hypothalamic and cerebral infarct volume were correlated with each other.

Key words: middle cerebral artery occlusion (MCAO), reperfusion model, hypothalamic infarction, diffusion weighted MR imaging (DWI), 2,3, 5-triphenyl tetrazoliumchloride (TTC) staining