title: Combination of early and delayed SPET imaging using technetium-99m ethyl cysteinate dimer immediately after local intra-arterial thrombolysis.
abstract: The aim of this study was to investigate the prognostic utility of post-treatment technetium-99m ethyl cysteinate dimer (99mTc-ECD) single-photon emission tomography (SPET) for predicting ischemic tissue outcome in cases involving embolic middle cerebral artery occlusion treated with local intra-arterial thrombolysis. We examined twenty-five patients with a moderately ischemic area determined using pretreatment technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) SPET, and with complete recanalization within 6 h. Post-treatment 99mTc-ECD SPET studies, consisting of scanning for 0.5-6.5 min (early scan) and 15-21 min (delayed scan) after tracer injection, were performed immediately after thrombolysis. The extent of the affected area outlined on pretreatment 99mTc-HMPAO SPET was used for the post-treatment early and delayed 99mTc-ECD SPET images, and the AR/CE ratio (ratio of affected regional activity to cerebellar activity) was calculated. The washout index of 99mTc-ECD in the affected area was also calculated by dividing the difference between the AR/CE ratio in the early and delayed images by the AR/CE ratio in the early image. Twelve patients without infarction or with small subcortical/basal ganglial infarction, ten with medium or large cortical infarction, and three with hemorrhage were identified by follow-up computed tomography. Although the AR/CE ratio in post-treatment early 99mTc-ECD SPET images was significantly higher in the hemorrhagic group than in the cortical infarction group, this value did not differentiate the reversible ischemia group from either the cortical infarction or the hemorrhagic group. The AR/CE ratio in post-treatment delayed 99mTc-ECD SPET images statistically differentiated the reversible ischemia group from both the cortical infarction and the hemorrhagic group. However, the difference between the cortical infarction and hemorrhagic groups was not statistically significant. The washout index of 99mTc-ECD statistically differentiated all three groups. This study demonstrated that a combination of early and delayed 99mTc-ECD SPET imaging performed immediately after thrombolysis predicts ischemic tissue outcome.
authors.affiliation: Department of Neurosurgery, Iwate Medical University, Uchimaru 19-1, Morioka, 020-8505, Japan. kuogasa@iwate-med.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Ogasawara
authors.forename: A
authors.initials: A
authors.lastname: Ogawa
authors.forename: H
authors.initials: H
authors.lastname: Konno
authors.forename: K
authors.initials: K
authors.lastname: Shibanai
authors.forename: M
authors.initials: M
authors.lastname: Doi
authors.forename: K
authors.initials: K
authors.lastname: Kuroda
authors.forename: T
authors.initials: T
authors.lastname: Yoshimoto
mesh_terms: D000328:Adult; D000368:Aged; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D015609:Organotechnetium Compounds; D010960:Plasminogen Activators / Q000627:therapeutic use; D011379:Prognosis; D019275:Radiopharmaceuticals; D011994:Recombinant Proteins / Q000627:therapeutic use; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D011994:Recombinant Proteins; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; C059659:technetium Tc 99m bicisate; D003545:Cysteine