The Method Of Quantification Measurement Of Cerebral Blood Flow With SPECT Using ～(99m)TC-ECD And Its Applications

Objective: 1, To establish a method on absolute measurement of cerebral blood flow with SPECT using 99mTc-ECD as imaging agent featured with stability, practicality, simpleness and easiness to be popularized in regular clinical activities. 2, To measure the values of regional cerebral blood flow on normal volunteers. 3, To assess clinical valuation of the approach of absolute measurement of regional cerebral blood flow.Materials and Method: 1, Subjects: 16 normal volunteers were divided into two age segments, The first segment includes 10 grown volunteers with 6 men and 4 women, aged 22~32years(mean 24.4 years); The second segment includes 6 children volunteers with 3 males and 3 females, aged from 5 to 16 years(mean 9.2 years). Patients include 33 subjects with two clear-cut different kinds of disorders, The first group includes 15 patients subjected with early syphilis, 5 males and 10 females, aged 19-36 years(mean 25.4 years). All 15 cases were excluded from diseases influencing cerebral blood flow including cardiac dysfunction, cervical vertebral, hypertension, systemic lupus erythematosus, angioma, stroke, dementia, epilepsy, transient ischemic attack, et al. The second group includes 18 patients suffered from epilepsy (6 males and 12 females), aged 5~15years(mean 9.6years). 4 cases in those had the history of asphyxiation during delivery. 2 cases had the history of head trauma. The others had no specific history that affect cerebral blood flow. 2, Imaging equipments: SPECT camera (AXIS PICKER) equipped with a low-energy high-resolution collimator. 3, Imaging agent: 99mTc-ECD, 99mTc is offered by Institute of Chinese Atomic Energy Research, and ECD is supplied by Institute of Chinese Nuclear Medicine Research. 4, Method: (1) Subjects Preparation: 400mg KClO4 for grown people and 200mg for children subjects. P.O, and 30min later, The patients lay supine on scintillgraphical bed with eyes closed, keeping low ambient noise, injected 99mTc-ECD1110MBq (30mCi) in the cubital vein of the right arm. (2) Data Acquisition: Planar dynamicscanning, Matrix: 128x128, 1s/Fx60, ZOOM Factor: 1 with a rectangular large-field gamma camera. 10 min after the injection of 99mTc-ECD, brain SPECT tomography was performed, Matrix: 128 x 128, Zoom factor: 1, Rotation angle: 6?projection, total 30 projections for each detector, along with low energy high resolution parallel collimators. (3),Data Analysis: Three ROIs were carefully drawn manually(right hemispheric tissue, left hemispheric tissue, and aortic arch), than smoothing 3 time-activity curves, shifting the hemispheric time-activity curve in order to match the peak time of both brain hemisphere and the aortic arch time-activity curves. Processing by self-programmed software, Ku value was first be resolved. Than BPI, mCBF will be produced respctively. At last, processing SPECT data, using Lassen correction to produce rCBF.Result: 1, Successfully established the method of absolute measurement of rCBF and obtained the normal values of rCBF on healthy volunteers in two common used age segments. 2, The rCBF values of patients suffered from the secondary syphilis have decreased diffusely. 3, The rCBF values of children patients with epilepsy have decreased in epileptogenic foci during interictal study.Conclusion: 1, Quantification measurement of cerebral blood flow can be carried out regularly in clinical activities with SPECT using 99mTc-ECD as imaging agent. 2, Quantification measurement of cerebral blood flow can be applied to direct the diagnosis and therapy on patients with early syphilis. 3, Quantification measurement of cerebral blood flow can be a promising tool for the identification of epiletogenic foci.