Accurate total-body Ki parametric imaging with shortened dynamic 18 F-FDG PET scan durations via effective data processing.

Abstract

Total-body dynamic positron emission tomography (dPET) imaging using 18 F-fluorodeoxyglucose(18 F-FDG) has received widespread attention in clinical oncology. However, the conventionally required scan duration of approximately 1 h seriously limits the application and promotion of this imaging technique. In this study, we investigated the possibility and feasibility of shortening the total-body dynamic scan duration to 30min post-injection (PI) with the help of a novel Patlak data processing algorithm for accurate Ki estimations of tumor lesions. Total-body dPET images acquired by uEXPLORER (United Imaging Healthcare Inc.) using 18 F-FDG of 15 patients with different tumor types were analyzed in this study. Dynamic images were reconstructed into 25 frames with a specific temporal dividing protocol for the scan data acquired 1 h PI. Patlak analysis-based Ki parametric imaging was conducted based on the imaging data corresponding to the first 30min PI, during which a Patlak data processing method based on cubic Hermite interpolation was applied. The resultant Ki images acquired by 30min dynamic PET data and the standard 1 h Ki images were compared in terms of visual imaging effect, region signal-to-noise ratio, and Ki estimation accuracy to evaluate the performance of the proposed Ki imaging method with a shortened scan duration. With the help of Patlak data processing, acceptable Ki parametric images were obtained from dynamic PET data acquired with a scan duration of 30min PI. Compared with Ki images obtained from unprocessed Patlak data, the resulting images from the proposed method performed better in terms of noise reduction. Moreover, Bland-Altman plot and Pearson correlation coefficient analysis showed that that 30min Ki images obtained from the processed Patlak data had higher accuracy for tumor lesions. Satisfactory Ki parametric images with high tumor accuracy can be acquired from dynamic imaging data corresponding to the first 30min PI. Patlak data processing can help achieve higher Ki imaging quality and higher accuracy regarding tumor lesion Ki values. Clinically, it is possible to shorten the dynamic scan duration of 18 F-FDG PET to 30min to acquire an accurate tumor Ki and further effective tumor detection with uEXPLORER scanners.