Department of Medical Physics, Kagawa University, Kagawa, Japan.
Department of Radiology, Kagawa University Hospital, Kagawa, Japan.
J Cereb Blood Flow Metab. 2018 May;38(5):780-792. doi: 10.1177/0271678X17713574. Epub 2017 Jun 9.
CBF, OEF, and CMRO 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 and CO 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 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.
CBF、OEF 和 CMRO 图像可以使用 PET 进行定量评估。其图像计算需要动脉输入函数，这需要有创性程序。本研究的目的是开发一种使用超快速 O 和 CO 协议图像的非侵入性方法，即图像衍生输入函数 (IDIF)。我们的技术包括使用一个公式，用组织曲线的速率常数来表示输入。对于多个组织曲线，通过最小化使用多个组织曲线的输入之间的差异来估计速率常数。估计的速率用于表示输入，估计输入的平均值用作 IDIF。该方法在人体受试者（n=24）中进行了测试。估计的 IDIF 与测量的 IDIF 很好地吻合。与有创方法相比，两种方法计算的 CBF、OEF 和 CMRO 值的差异较小（<10%），且相关性较强（r=0.97）。模拟结果表明，与假设参数相关的误差小于约 10%。我们的结果表明，IDIF 可以从组织曲线重建，这表明使用非侵入性技术评估 CBF、OEF 和 CMRO 的可能性。
