Figure 2.

Evaluation of the HI brain injury model by cranial ultrasonography. Representative images are shown for the sham operation group at 24 h after surgery (Sham) and for the hypoxic-ischemic brain damage group at 0 h (i.e., immediately after surgery; HIBD-0 h), 4 h (HIBD-4 h), 8 h (HIBD-8 h), 12 h (HIBD-12 h) and 24 h (HIBD-24 h) after surgery. L: left side; R: right side. Blood flow velocity in the right vertebrobasilar artery was increased at 4 h after modeling. Parts of the brain parenchyma in the HIBD group showed enhanced echogenicity at 24 h. The right vertebral artery exhibited stenosis in its proximal segment. Blood flow through the left vertebral artery regurgitated through the basilar artery to the right side; this phenomenon of blood stealing was not observed in the other groups.