Improved Clinical Workflow for Whole-Body Patlak Parametric Imaging Using Two Short Dynamic Acquisitions.

Objective: We sought to explore the feasibility of shorter acquisition times using two short dynamic scans for a multiparametric PET study and the influence of quantitative performance in shortened dynamic PET.

Methods: Twenty-one patients underwent whole-body dynamic F-FDG PET/CT examinations on a PET/CT (Siemens Biograph Vision) with a total scan time of 75 min using continuous bed motion for Patlak multiparametric imaging. Two sets of Patlak multiparametric images were produced: the standard MR and DV images (MR- and DV-) and two short dynamic MR and DV images (MR- and DV-), which were generated by a 0-75 min post injection (p.i.) dynamic PET series and a 0-6 min + 60-75 min p.i. dynamic PET series, respectively. The maximum, mean, and peak values of the standard and two short dynamic multiparametric acquisitions were obtained and compared using Passing-Bablok regression and Bland-Altman analysis.

Results: High correlations were obtained between MR- and MR-, and between DV- and DV- for both normal organs and all lesions (0.962 ≦ Spearman's rho ≦ 0.982, < 0.0001). The maximum, mean, and peak values of the standard and two short dynamic multiparametric acquisitions were also in agreement. For normal organs, the Bland-Altman plot showed that the mean bias of MRmax, MRmean, and MRpeak was -0.002 (95% CI: -0.032-0.027), -0.002 (95% CI: -0.026-0.023), and -0.002 (95% CI: -0.026-0.022), respectively. The mean bias of DVmax, DVmean, and DVpeak was -3.3 (95% CI: -24.8-18.2), -1.4 (95% CI: -12.1-9.2), and -2.3 (95% CI: -15-10.4), respectively. For lesions, the Bland-Altman plot showed that the mean bias of MRmax, MRmean, and MRpeak was -0.009 (95% CI: -0.056-0.038), -0.004 (95% CI: -0.039-0.031), and -0.004 (95% CI: -0.036-0.028), respectively. The mean bias of DVmax, DVmean, and DVpeak was -8.4 (95% CI: -42.6-25.9), -4.8 (95% CI: -20.2-10.6), and -4.0 (95% CI: -23.7-15.6), respectively.

Conclusions: This study demonstrates the feasibility of using two short dynamic scans that include the first 0-6 min and 60-75 min scans p.i. for Patlak multiparametric images, which can increase patient throughout for parametric analysis.