Feasibility of 99Tcm-HL91 single photon emission computed tomography and CT imaging in detecting hypoxic brain tissue following hypertensive cerebral hemorrhage / 中国组织工程研究

ABSTRACT

BACKGROUND: The presence of ischemic penumbra in hypertensive cerebral hemorrhage is the hot spot and still controversial. The value of 4,9-diaza-2, 3, 10, 10-tetramethydodecan-2, 11-dione dioxime (HL91) tagged with 99Tcm on detecting the hypoxic brain tissue surrounding the hypertensive cerebral hemorrhage nidus, which represents the penumbra is still waited for confirmation.OBJECTIVE: To investigate the value of 99Tcm-HL91 single photon emission computed tomography (SPECT)/CT imaging on detecting hypoxic tissue in the patients with hypertensive cerebral hemorrhage.DESIGN: Control study.SETTING: Department of Neurology, Jiangmen Municipal Central Hospital, Guangdong Province.PARTICIPANTS: This series included 22 patients with hypertensive cerebral hemorrhage examined between March 2004 and March 2005 in Jiangmen Municipal Central Hospital. All cases revealed sudden onset of the disease, presented with the history of hypertension. These patients were diagnosed with hypertension after admission. The hemorrhage occurred in the anterior circulation territory in all cases and the volume of hemorrhage ranged from 10 mL to 63 mL. Minimally invasive stereotaxic aspiration was performed in 3 cases, craniotomy debridement in 1 case, and expectant treatment in the remaining cases. The period of time from the symptom onset to the examination was form 12 hours to 1.5 years, including more than 1 month in 5 cases. Control group consisted of 6 cases were clinically diagnosed with melancholia and anxiety disorders. Cerebral hemorrhage and acute cerebral infarction were ruled out by integrated CT scan in these 6 cases.METHODS: All 22 patients with hypertensive cerebral hemorrhage and 6 normal controls underwent 99Tcm-HL91 SPECT imaging and combined with CT scan.MAIN OUTCOME MEASURES: ① Identification of radioactive concentrations at one side of the peripheral zone of the lesions by visual analysis on two consecutive slices at two different axial directions were considered aspositive hypoxic imaging. ② The other was ROI semi-quantification measuring radiocounting ratio (R) between the region of visible radioactive concentrations, the center of the nidus, and their contralateral mirror region. R ＜ 0.8 or R ＞ 1.2 was considered to be abnormal. ③ Hypoxic region was defined by integrated CT fused imaging, and its volume was calculated using Xelerix workstation. The volume of the hypoxic tissue and hemorrhage was computed by Duotian formula length of the maximum cross-section of the hemorrhage × width × slice number × 1/2.RESULTS: All 28 patients were involved in the final analysis. ① Perihemorrhagic radioactive concentrations which represented positive hypoxic imaging was revealed on 99Tcm-HL91 SPECT imaging in 18 cases out of 22 patients with cerebral hemorrhage, and positive rate was 77.78%. Bilateral cerebral hemisphere showed symmetric negative imaging in 6 cases of the control group. ② The fused SPECT/CT images revealed hypoxic region was around the intracerebral hemorrhage, small portion was within the nidus of hemorrhage with irregular shape. R value was 1.75±0.10 in perihemorrhagic hypoxic region in 18 cases with positive imaging, and R value was 1.05±0.11 in the basal ganglia in the control group. There was statistically significant difference between the two groups (P ＜ 0.01). ③ There was a positive linear correlation between maximum volume of hematom and hypoxia volume (correlation coefficient r=0.7517, P ＜ 0.01).CONCLUSION: Relying on the mechanism about demonstrating the hypoxic tissue on fused SPECT/CT imaging, the hypoxic tissue would represent the penumbra may exist in the territories located around the cerebral hemorrhage. The positive territories may be reversible, I.e. The important portion of the penumbra. 99Tcm-HL91 SPECT/CT imaging can detect the hypoxic tissue surrounding the cerebral hemorrhage. The volume of hypoxic tissue is correlated with the hemorrhagic volume. The procedure is promising and could be applied in clinic.