Fig. 3From: An automatic pipeline for PET/MRI attenuation correction validation in the brainMR to CT-based PET attenuation correction relative (a–c) and absolute (d–f) bias in two synthetic spherical lesions inserted at two brain locations. Lesions were reconstructed with (a and d) and without (b and e) the background activity and from the corresponding spherical ROIs in the original PET images (c and f)Back to article page