Advanced Functional Tumor Imaging and Precision Nuclear Medicine Enabled by Digital PET Technologies

Figure 2

Intraindividual comparison in a patient scanned on the cPET/CT (Gemini 64 ToF, Philips Healthcare, Cleveland, Ohio, USA) system and a precommercial release dPET/CT (Vereos, Philips Healthcare, Cleveland, Ohio, USA) system using different reconstruction matrix/voxel volume sizes with a 3D line-of-response TOF blob-based algorithm [5, 17, 22, 23]. The patient was intravenously given a standard dose of 485 MBq of ¹⁸F-FDG and then underwent imaging on the dPET/CT system at 50 min and the cPET/CT system at 76 min after injection. Both cPET and dPET emission scans were acquired with 90 s per bed position. Although there is a discrete ¹⁸F-FDG-avid lesion noted in the right hilar region on both cPET and dPET images, there is a subcentimeter lesion in the right supraclavicular region which is only apparent on dPET images and becomes more conspicuous (and more suspicious) with higher definition image reconstructions. (a) Maximum intensity projection images from standard definition cPET (matrix size = 144 × 144, voxel volume = 4 mm³), standard definition dPET (144 × 144, 4 mm³), high definition dPET (288 × 288, 2 mm³), and ultrahigh definition dPET (576 × 576, 1 mm³). Point spread function and Gaussian filtering were applied to both high definition and ultrahigh definition dPET reconstructed images but not to standard definition dPET or cPET images. (b) Axial images from standard definition cPET, standard definition dPET, high definition dPET, and ultrahigh definition dPET taken at the level of the lesion in the right supraclavicular region. Region-of-interest analysis of the right supraclavicular lesion demonstrates FDG avidity similar to background on the cPET whereas the conspicuity and values increase with higher definition dPET. This case illustrates the capability of dPET technology to substantially improve lesion detectability, lesion characterization, and diagnostic confidence.

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