Diagnostic use of neuro-spect quantified with 99mTc-ECD: A model based on normal data

Abstract

OBJECTIVEThe purpose of the present study was to prospectively quantify the normal limits of brain perfusion using specific software in a group of asymptomatic young volunteers submitted to single-photon emission tomography (SPECT) with 99mTc-ethyl cysteinate dimer (99mTc-ECD).METHODSWe used 15 MBq/kg of intravenous 99mTc-ECD in 30 healthy volunteers submitted to brief neuropsychological tests and a clinical questionnaire. These data were normalized relative to the cerebellum (Group 1) and to the brain cortex (Group 2). Statistical analysis was performed with Student's t-test. The average radioactivity was 6.5 million counts/study.RESULTSThe normalized (Group I) revealed an average value of 78.03%, with standard deviation (SD) of 4.07. Two volunteers in this group had slightly greater than two standard deviations from the mean. When we used (Group II), the average value was 71.01%, with a SD of 4.66. We observed a difference between groups of 9% (P<0.001).CONCLUSIONThe present study suggests normal cortical perfusional values for a group of young asymptomatic volunteers, utilizing 99mTc-ECD. This allows further quantification of neuro-SPECT data, specifically comparisons across patient populations. Furthermore, this method represents a new tool that can be used to further explore the field of neuroimaging, particularly neuropsychiatry.

Brain SPECT scans in students with specific learning disability

“…For the first or “baseline“ scan, the student was made to sit with eyes open in a quiet, dimly lit room for a period of 30–40 min and then injected intravenously with 20 mCi of 99m Tc labelled L, L-ethylcysteinate dimer ( 99m Tc-ECD), which has been widely used to study changes in relative rCBF using SPECT systems. [310] This technique is called brain perfusion, and it relies on the coupled behaviour of blood flow and metabolism, which is used as a marker of neuronal activity. [310] An hour later, the student was imaged on a dual-headed GE Infinia Hawkeye SPECT/CT.…”

“…[310] This technique is called brain perfusion, and it relies on the coupled behaviour of blood flow and metabolism, which is used as a marker of neuronal activity. [310] An hour later, the student was imaged on a dual-headed GE Infinia Hawkeye SPECT/CT.…”