Fast PET Preview Image Reconstruction, Streaming, and Visualization During Data Acquisition: A Preliminary Study.

PET acquisition and reconstruction are time-consuming. A PET preview image is commonly reconstructed at the end of data acquisition of each bed-position frame in the step-and-shoot mode. We propose a scheme to reconstruct, stream, and visualize the PET preview image during acquisition to provide quasi-real-time visual feedback. As acquisition proceeds, event data are processed continuously by a backprojection method using time-of-flight kernels while corrections are applied only for sensitivity, time span, and decay. A preview update can be scheduled by frame or by a configured time interval. To create a preview image, the 3-dimensional volume of the current segment is knit with other existing segments. The knitted volume is projected onto a 2-dimensional plane, and the resultant gray-scale image is streamed to a display component for visualization. By using fast and simple reconstruction and correction, the described scheme balances processing speed and image quality to provide early and frequent visual feedback. Results show that the preview creation, streaming, and visualization time are shorter than the acquisition time for a typical whole-body study. Fast feedback is achieved during PET acquisition, which provides clinicians with an indication of data acquisition and an estimation of image quality and allows early corrective measure and image quality control if necessary.