Digitally quantifying cerebral hemorrhage using Photoshop and Image J.

A spectrophotometric hemoglobin assay is widely used to estimate the extent of brain hemorrhage by measuring the amount of hemoglobin in the brain. However, this method requires using the entire brain sample, leaving none for histology or other assays. Other widely used measures of gross brain hemorrhage are generally semi-quantitative and can miss subtle differences. Semi-quantitative brain hemorrhage scales may also be subject to bias. Here, we present a method to digitally quantify brain hemorrhage using Photoshop and Image J, and compared this method to the spectrophotometric hemoglobin assay. Male Sprague-Dawley rats received varying amounts of autologous blood injected into the cerebral hemispheres in order to generate different sized hematomas. 24h later, the brains were harvested, sectioned, photographed then prepared for the hemoglobin assay. From the brain section photographs, pixels containing hemorrhage were identified by Photoshop and the optical intensity was measured by Image J. Identification of hemorrhage size using optical intensities strongly correlated to the hemoglobin assay (R=0.94). We conclude that our method can accurately quantify the extent of hemorrhage. An advantage of this technique is that brain tissue can be used for additional studies.

99mTc-HYNIC-annexin V SPECT imaging of acute stroke and its response to neuroprotective therapy with anti-Fas ligand antibody.

PURPOSE: The first aim of the study was to determine whether (99m)Tc-HYNIC-annexin V, a marker of cellular stress and apoptosis, can detect ischemic injury in patients with acute stroke. Secondly, we wished to test radiolabeled annexin's ability to monitor therapy in a rodent model of focal ischemic injury. METHODS: SPECT imaging of patients was performed between 1 and 2 h after intravenous injection of 30 mCi (1,110 MBq) of tracer. Eight MFL4 (anti-FasL) antibody-treated (400 microg i.p. days 0 and 3) and 21 control adult male Sprague-Dawley rats underwent small animal SPECT imaging with 5-10 mCi (185-370 MBq) of tracer, 1 and 6 days after a 2-h intraluminal thread occlusion of the left middle cerebral artery. RESULTS: Two patients with acute stroke had regions of multifocal annexin uptake that correlated with sites of restricted diffusion on MRI. Anti-FasL antibody treatment significantly reduced annexin uptake by 92% with a 60% decrease in the number of caspase-8 staining (apoptotic) neurons on day 1. On day 6, treated animals had an 80% reduction in tracer uptake with a 75% decrease in infarct size as compared with controls. Annexin uptake in controls and treated animals (day 6) linearly correlated with infarct size (r (2)=0.603, p=0.0036) and the number of TUNEL-positive (apoptotic) nuclei (r (2)=0.728, p=0.00084). CONCLUSION: Annexin imaging shows foci of increased uptake at sites of ischemic injury in patients with acute stroke. Annexin imaging can assess the effects of therapy for ischemic cerebral injury in rats, suggesting its potential as a non-invasive indicator of drug efficacy in future clinical trials.

Detection of focal hypoxic-ischemic injury and neuronal stress in a rodent model of unilateral MCA occlusion/reperfusion using radiolabeled annexin V.

In this study we wished to determine whether technetium-99m annexin V, an in vivo marker of cellular injury and death, could be used to noninvasively monitor neuronal injury following focal middle cerebral artery (MCA) occlusion/reperfusion injury. Sixteen adult male Sprague-Dawley rats (along with four controls) underwent left (unilateral) MCA intraluminal beaded thread occlusion for 2 h followed by reperfusion. One hour following tail vein injection of 5-10 mCi of (99m)Tc-annexin V, animals underwent either single-photon emission computerized tomography (SPECT) or autoradiography followed by immunohistochemical analyses. There was abnormal, bilateral, multifocal uptake of (99m)Tc-annexin V in each cerebral hemisphere as seen by both SPECT and autoradiography at 4 h and 1, 3, and 7 days after initiation of occlusion. The average maximal annexin V uptake at 4 h was 310%+/-85% and 365%+/-151% above control values (P<0.006) within the right and left hemispheres, respectively, peaking on day 3 with values of 925%+/-734% and 1,194%+/-643% (P<0.03) that decreased by day 7 to 489%+/-233% and 785%+/-225% (P<0.01). Total lesional volume of the left hemisphere was 226%, 261%, and 451% ( P<0.03) larger than the right at 4, 24, and 72 h after injury, respectively. Annexin V localized to the cytoplasm of injured neurons ipsilateral to the site of injury as well as to otherwise normal-appearing neurons of the contralateral hemisphere as confirmed by dual fluorescent microscopy. It is concluded that there is abnormal bilateral, multifocal annexin V uptake, greater on the left than on the right side, within 4 h of unilateral left MCA ischemic injury and that the uptake peaks at 3 days and decreases by 7 days after injury. This pattern suggests that neuronal stress may play a role in the response of the brain to focal injury and be responsible for annexin V uptake outside the region of ischemic insult.