Comparison of single-scatter simulation and Monte Carlo single-scatter simulation on Philips Ingenuity TF PET/MR

Scatter correction is an essential data correction in quantitative PET imaging. In this work, a prototype of single scatter simulation using fast Monte-Carlo method (MC-SSS) for scatter estimate scaling instead of tail fitting was evaluated concurrently with the existing single-scatter simulation (SSS) algorithm. Reconstructions with both MC-SSS and SSS were performed on phantom and patient data collected with the Philips Ingenuity TF PET/MR scanner. Activity values and line profiles were measured in the phantom studies while patient studies were evaluated in terms of contrast differences, artifact reduction and time-activity-curve (TAC) consistency. The phantom studies show that MC-SSS and SSS do not result in large systematic over- or underestimation of scatter, with mean difference up to 5.7 %, where MC-SSS produces systematically higher values. In patient studies, an improvement in image contrast and TAC consistency is seen with the MC-SSS over SSS. MC-SSS effectively eliminates scatter artifacts near the bladder compared to SSS. In specific conditions, where tail fitting quality of SSS might not be optimal, MC-SSS outperforms SSS, as seen in the patient study.