A number of studies using single-photon emission tomography (SPET) have shown perfusion changes with age in several cortical and subcortical areas, which might distort the results of perfusion imaging studies of neuropsychiatric disorders. Technetium-99m labelled ethyl cysteinate dimer (ECD) and hexamethylpropylene amine oxime (HMPAO) are both used as markers of cerebral perfusion, but have different pharmacokinetics and retention patterns. The aim of this study was to determine whether age and gender effects on perfusion SPET differ depending on whether 99mTc-HMPAO or 99mTc-ECD is used. Forty-five subjects (20 male and 25 female, mean age 52.8±6.6 years) were assigned to 99mTc-HMPAO SPET (HMPAO group), and 39 subjects (24 male and 15 female, mean age 52.6±6.7 years) to 99mTc-ECD SPET (ECD group). SPET images were obtained about 10 min after intravenous injection of approximately 800 MBq 99mTc-HMPAO or 99mTc-ECD using the same SPET scanner. Three-dimensional volumetric magnetic resonance imaging was performed to as7sess morphological changes in the grey matter. All image processing and statistical analyses were performed using SPM99 software. An area in the right anterior frontal lobe showed an increase in perfusion with age only in the HMPAO group, whereas areas in the bilateral retrosplenial cortex showed decreases in perfusion with age only in the ECD group; neither group showed corresponding changes in the grey matter. The present study shows that different effects of age on perfusion are observed depending on whether 99mTc-HMPAO and 99mTc-ECD is used. This suggests that the results of perfusion SPET are differently confounded depending on the tracer used, and that perfusion SPET with these tracers has limitations when used in research on subtle perfusion changes.
|Number of pages||9|
|Journal||European journal of nuclear medicine and molecular imaging|
|Publication status||Published - 2003 Nov|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging