Fig. 4From: Cross-calibration of the Siemens mMR: easily acquired accurate PET phantom measurements, long-term stability and reproducibilityGradient effect in PET quantification caused by μ-map shifts (misregistrations). PET images of the mCT water phantom with an 8-mm horizontal shift of the μ-map (a) and a 10-mm opposite shift (b). c The horizontal profile plots (the red and blue overlays in a and b) through the PET imagesBack to article page