Importance of gated CT acquisition for the quantitative improvement of the gated PET/CT in moving phantom

Abstract

In respiratory motion, PET acquisition in the static mode underestimated the radioactivity and overestimated the dimensions. Neither SCT nor ACT improved these errors. Although PET acquisition in the gated mode improved the quantification of PET/CT images, the additional gated CT acquisition using 4DCT is required for further improvement.

The influence of respiratory motion on the cumulative SUV-volume histogram and fractal analyses of intratumoral heterogeneity in PET/CT imaging

“…In the histograms, the peaks were broad and unclear because of the smearing of radioactivity due to respiratory motion. The peaks could not be separated from each other and thus the resulting CSH curves of the 3 phantoms showed a similar pattern [12,13,17]. In the fractal analysis, the FDs of the HO and HE1 phantoms did not differ from each other and were smaller than that of the HE2 phantom.…”

“…The amplitude of respiratory motion of 2 cm was chosen because the average amplitude of normal free breathing in the cranio-caudal direction was reported to be smaller than 2 cm [16]. In addition, we also selected 2 cm as the amplitude for simulating normal free breathing in our previous study [17].…”

Use of FDG-PET in Radiation Treatment Planning for Thoracic Cancers

“…Respiratory-gated PET imaging is currently expected to improve the quantification of PET [68]. Sakaguchi et al reported that gated imaging acquisition improved the quality of FDG-PET imaging in a moving phantom model [69]. Daouk et al evaluated 48 pulmonary nodules in 43 patients by respiratory-gated PET and ungated method [70].…”