Reconstruction of input functions from a dynamic PET image with sequential administration of 15O2 and H215O for noninvasive and ultra-rapid measurement of CBF, OEF, and CMRO2

• Published in: Journal of cerebral blood flow and metabolism Vol. 38; no. 5; pp. 780 - 792
• Main Authors: Kudomi, Nobuyuki, Maeda, Yukito, Yamamoto, Hiroyuki, Yamamoto, Yuka, Hatakeyama, Tetsuhiro, Nishiyama, Yoshihiro
• Format: Journal Article
• Language: English
• Published: Sage UK: London, England SAGE Publications 09.06.2017
• Subjects: Original
• ISSN: 0271-678X; 1559-7016
• DOI: 10.1177/0271678X17713574

CBF, OEF, and CMRO 2 images can be quantitatively assessed using PET. Their image calculation requires arterial input functions, which require invasive procedure. The aim of the present study was to develop a non-invasive approach with image-derived input functions (IDIFs) using an image from an ultra-rapid O 2 and C 15 O 2 protocol. Our technique consists of using a formula to express the input using tissue curve with rate constants. For multiple tissue curves, the rate constants were estimated so as to minimize the differences of the inputs using the multiple tissue curves. The estimated rates were used to express the inputs and the mean of the estimated inputs was used as an IDIF. The method was tested in human subjects ( n  = 24). The estimated IDIFs were well-reproduced against the measured ones. The difference in the calculated CBF, OEF, and CMRO 2 values by the two methods was small (<10%) against the invasive method, and the values showed tight correlations ( r  = 0.97). The simulation showed errors associated with the assumed parameters were less than ∼10%. Our results demonstrate that IDIFs can be reconstructed from tissue curves, suggesting the possibility of using a non-invasive technique to assess CBF, OEF, and CMRO 2 .