Background: Cerebral blood flow (CBF) quantitation using technetium-99m hexamethylpropyleneamine oxime (99mTc-HMPAO) generally requires assessment of input function by arterial blood sampling, which would be invasive for small animals. We therefore performed chest dynamic planar imaging, instead of arterial blood sampling, to estimate the input function and establish noninvasive quantitation method of rat CBF using the image-derived input function.
Results: Integrated radioactivity concentration in the heart-blood pool on planar images (AUCBlood-planar) was identical to that in arterial blood samples (AUCBlood-sampling). Radioactivity concentration in the brain determined by SPECT imaging (CBrain-SPECT) was identical to that using brain sampling (CBrain-sampling). Noninvasively calculated CBF obtained by dividing CBrain-SPECT by AUCBlood-planar was well correlated with conventionally estimated CBF obtained by dividing CBrain-sampling by AUCBlood-sampling.
Conclusion: Rat CBF could be noninvasively quantitated using 99mTc-HMPAO chest dynamic planar imaging and head SPECT imaging without arterial blood sampling.
Keywords: 99mTc-HMPAO; Cerebral blood flow; Image-derived input function; Planar imaging; Rat.