Impact of tissue photon attenuation in small animal cardiac PET imaging

Nobuyuki Hayakawa, Tomohiko Yamane, Anahi Paula Arias-Loza, Tetsuya Shinaji, Hiroshi Wakabayashi, Constantin Lapa, Rudolf A. Werner, Mehrbod Som Som Javadi, Theo Pelzer, Takahiro Higuchi

Research output: Contribution to journalArticle

Abstract

Objectives Tissue photon attenuation is one of the essential artifacts requiring correction in clinical cardiac positron emission tomography (PET) imaging. However, due to small body size its impact on diagnostic accuracy in small rodents is considered to be limited or even ignorable. The present cardiac PET study compares lean and obese rats to determine the influence of tissue attenuation on quantitative assessment as well as regional tracer distribution. Methods A dedicated small animal PET system equipped with a 57Co rotating source for transmission was used. To assess the impact of tissue attenuation in rats with different body sizes, cardiac 18F­FDG -PET studies for Zucker diabetic fatty rats (obese rats) and Zucker lean rats (lean rats) were performed. The radiotracer activity reduction by attenuation was compared between the two groups. Regional tracer distribution calculated with and without attenuation correction was also assessed. Results The chest diameter was significantly longer in obese than in lean rats (5.6 ± 0.3 cm in obese and 4.5 ± 0.2 cm in lean rats, p < 0.0001). Whereas the activity reduction by attenuation was significantly greater in obese than in lean rats (44.1 ± 2.5% and 5.1 ± 3.1%, p < 0.0001), the regional variation of tissue attenuation among the ventricular walls was minimal in both lean (p = 0.73) and obese rats (p = 0.65). Conclusion Attenuation correction is indispensable for accurate comparison of cardiac tracer activity between animals with different body size, whereas it can be omitted for evaluation of regional tracer distribution.

Original languageEnglish (US)
Pages (from-to)257-260
Number of pages4
JournalInternational Journal of Cardiology
Volume227
DOIs
Publication statusPublished - Jan 15 2017

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Keywords

  • Attenuation correction
  • Cardiac PET
  • Small animal
  • Tissue photon attenuation

ASJC Scopus subject areas

  • Medicine(all)
  • Cardiology and Cardiovascular Medicine

Cite this

Hayakawa, N., Yamane, T., Arias-Loza, A. P., Shinaji, T., Wakabayashi, H., Lapa, C., ... Higuchi, T. (2017). Impact of tissue photon attenuation in small animal cardiac PET imaging. International Journal of Cardiology, 227, 257-260. https://doi.org/10.1016/j.ijcard.2016.11.119