Department of Nuclear Medicine, Netherlands Cancer Institute, Amsterdam, The Netherlands.
Department of Physics, Netherlands Cancer Institute, Amsterdam, The Netherlands.
J Appl Clin Med Phys. 2020 Sep;21(9):272-277. doi: 10.1002/acm2.12991. Epub 2020 Aug 13.
The goal of this study was to find the optimal combination of collimator, photopeak and scatter correction for Lutetium ( Lu) SPECT/CT imaging.
Three experiments [sphere-to-background ratios (SBR) 50:1, 10:1, and 2:1] were performed with the NEMA Image Quality phantom filled with Lu-trichloride. SPECT/CT acquisitions were performed with the medium-energy low-penetration (MELP) collimator and Tc/Krypton collimator. For each acquisition six reconstructions, all with attenuation correction (AC), were made: the 113-keV photopeak only, the 208-keV photopeak only and both photopeaks combined, each with or without scatter correction (SC). Image quality was assessed using contrast-to-noise ratios (CNR), quantification accuracy by means of recovery coefficients (RCs) and the spatial resolution using line profiles.
With SBR 50:1 and 10:1, both collimators met the Rose criterion (CNR > 5), whereas the MELP collimator showed a higher CNR for the 2:1 ratio. The RC was higher with the MELP collimator, most explicit after the 208-keV AC/SC reconstruction for all acquisitions. The line profiles showed a better spatial resolution for the MELP collimator and the 208-keV AC/SC reconstructions.
Lu SPECT/CT image quality and quantification was most optimal when acquired with the MELP collimator and reconstructed using the 208-keV photopeak, with AC and SC.
本研究旨在寻找镥（Lu）SPECT/CT 成像中准直器、光电峰和散射校正的最佳组合。
用填充 Lu 三氯化物的 NEMA 图像质量体模进行了三个实验[球对背景比（SBR）为 50:1、10:1 和 2:1]。使用中能低穿透性（MELP）准直器和 Tc/氪准直器进行 SPECT/CT 采集。对于每次采集，都进行了六种具有衰减校正（AC）的重建：仅使用 113keV 光电峰、仅使用 208keV 光电峰以及同时使用两种光电峰，每种光电峰都具有或不具有散射校正（SC）。使用对比噪声比（CNR）评估图像质量，使用恢复系数（RC）评估定量准确性，使用线轮廓评估空间分辨率。
在 SBR 为 50:1 和 10:1 时，两种准直器均符合罗斯标准（CNR>5），而 MELP 准直器在 SBR 为 2:1 时显示出更高的 CNR。RC 随 MELP 准直器的升高而升高，在所有采集后进行的 208keV AC/SC 重建后表现得更为明显。线轮廓显示 MELP 准直器和 208keV AC/SC 重建的空间分辨率更好。
当使用 MELP 准直器采集并使用 208keV 光电峰、AC 和 SC 进行重建时，Lu SPECT/CT 的图像质量和定量最佳。
