Dynamic whole-body PET imaging: principles, potentials and applications

Abstract

Purpose In this article, we discuss dynamic whole-body (DWB) positron emission tomography (PET) as an imaging tool with significant clinical potential, in relation to conventional standard uptake value (SUV) imaging. Background DWB PET involves dynamic data acquisition over an extended axial range, capturing tracer kinetic information that is not available with conventional static acquisition protocols. The method can be performed within reasonable clinical imaging times, and enables generation of multiple types of PET images with complementary information in a single imaging session. Importantly, DWB PET can be used to produce multi-parametric images of (i) Patlak slope (influx rate) and (ii) intercept (referred to sometimes as Bdistribution volume^), while also providing (iii) a conventional 'SUV-equivalent' image for certain protocols. Results We provide an overview of ongoing efforts (primarily focused on FDG PET) and discuss potential clinically relevant applications. Conclusion Overall, the framework of DWB imaging [applicable to both PET/CT(computed tomography) and PET/MRI (magnetic resonance imaging)] generates quantitative measures that may add significant value to conventional SUV imagederived measures, with limited pitfalls as we also discuss in this work.

Impact of Tissue Classification in MRI-Guided Attenuation Correction on Whole-Body Patlak PET/MRI

“…Our previous studies have proposed and validated a WB dynamic PET acquisition protocol for routine clinical imaging [17][18][19][20][21][22][23]. It is feasible to combine SUV and Patlak K i WB PET imaging in clinical oncology within a single clinical acceptable scanning time [30].…”

“…However, conventional SUV PET imaging only presents the three-dimensional (3D) spatial distribution of a tracer's activity concentration averaged over a single time frame of a PET acquisition. Recently, there has been increasing interest in dynamic WB Patlak-derived net uptake rate constant (K i ) PET imaging owing to its ability to estimate K i parametric images across the whole human body as a complement to standard-of-care SUV imaging [17][18][19][20][21][22][23]. Unlike static acquisitions and the SUV metric, dynamic PET imaging allows for tracking of the four-dimensional (4D) spatio-temporal distribution of the tracer uptake post-injection, thereby enabling the estimation of the tracer's K i value which may be of high clinical importance for certain types of malignancy.…”

“…Our previous studies reported on a clinically feasible WB dynamic PET acquisition protocol using both indirect and direct 4D Patlak reconstruction methods [17][18][19][20][21][22][23]. The purpose of the present study is to investigate the impact of four-tissue class segmentation in MRI-guided attenuation correction of SUV and Patlak K i images to assess the feasibility of WB Patlak PET/MRI.…”

Improvement of image quality in PET using post-reconstruction hybrid spatial-frequency domain filtering

“…Filtering parameter optimization and fine tuning could be achieved more effectively when the frequency response of the filter is limited independent of the frequency content of the input image. These features make the hybrid approach a versatile tool for denoising of PET images with different tracers presenting with various spatial and temporal distributions, For instance, in dynamic or low-dose PET imaging (Karakatsanis et al 2016, Yan et al 2016, Rahmim et al 2018 where the low SNR induces severe bias and large variance in estimates of physiological parameters, image denoising capable of preserving the spatial resolution and quantitative accuracy is highly desirable. In this regard, the hybrid approach appears to be an effective denoising technique owing to its relatively high quantitative accuracy and improved SNR.…”

Whole‐body parametric PET imaging will replace conventional image‐derived PET metrics in clinical oncology

“…As my opponent notes in supporting Dr. Carson's idea of using dynamic scanning during the uptake phase, more studies are required to determine when dynamic whole‐body scans will prove beneficial. Commercial manufacturers are also starting to make multi‐pass continuous bed motion acquisition protocols available so that dynamic whole‐body PET will be increasingly feasible in the clinic. With this capability available, we can expect to see a rapid increase in the number of whole‐body dynamic studies that will provide evidence for the potential impact of whole‐body dynamic studies.…”