PT  - JOURNAL ARTICLE
AU  - Guobao Wang
AU  - Lorenzo Nardo
AU  - Mamta Parikh
AU  - Yasser G. Abdelhafez
AU  - Elizabeth Li
AU  - Benjamin A. Spencer
AU  - Jinyi Qi
AU  - Terry Jones
AU  - Simon R. Cherry
AU  - Ramsey D. Badawi
TI  - Total-Body PET Multiparametric Imaging of Cancer Using a Voxelwise Strategy of Compartmental Modeling
AID  - 10.2967/jnumed.121.262668
DP  - 2022 Aug 01
TA  - Journal of Nuclear Medicine
PG  - 1274--1281
VI  - 63
IP  - 8
4099  - http://jnm.snmjournals.org/content/63/8/1274.short
4100  - http://jnm.snmjournals.org/content/63/8/1274.full
SO  - J Nucl Med2022 Aug 01; 63
AB  - Quantitative dynamic PET with compartmental modeling has the potential to enable multiparametric imaging and more accurate quantification than static PET imaging. Conventional methods for parametric imaging commonly use a single kinetic model for all image voxels and neglect the heterogeneity of physiologic models, which can work well for single-organ parametric imaging but may significantly compromise total-body parametric imaging on a scanner with a long axial field of view. In this paper, we evaluate the necessity of voxelwise compartmental modeling strategies, including time delay correction (TDC) and model selection, for total-body multiparametric imaging. Methods: Ten subjects (5 patients with metastatic cancer and 5 healthy volunteers) were scanned on a total-body PET/CT system after injection of 370 MBq of 18F-FDG. Dynamic data were acquired for 60 min. Total-body parametric imaging was performed using 2 approaches. One was the conventional method that uses a single irreversible 2-tissue-compartment model with and without TDC. The second approach selects the best kinetic model from 3 candidate models for individual voxels. The differences between the 2 approaches were evaluated for parametric imaging of microkinetic parameters and the 18F-FDG net influx rate, Ki. Results: TDC had a nonnegligible effect on kinetic quantification of various organs and lesions. The effect was larger in lesions with a higher blood volume. Parametric imaging of Ki with the standard 2-tissue-compartment model introduced vascular-region artifacts, which were overcome by the voxelwise model selection strategy. Conclusion: The time delay and appropriate kinetic model vary in different organs and lesions. Modeling of the time delay of the blood input function and model selection improved total-body multiparametric imaging.