Fig. 1

Representative imaging. a demonstrates maximum intensity projections (MIPs) of two patients imaged with ¹⁸F-FDG and ¹⁸F-GE-180. The two left images are of a patient who has increased right knee joint uptake with ¹⁸F-FDG, not seen with ¹⁸F-GE-180, which is also demonstrated on axial and coronal fused images in b. The images with ¹⁸F-GE-180 demonstrate a typical pattern of physiological uptake with marrow uptake in the proximal femurs and diffuse muscle uptake. The two right images of Fig. a are of a separate patient who demonstrates marked uptake within the marrow down to the proximal tibiae with ¹⁸F-GE-180. A similar but less intense uptake is seen with ¹⁸F-FDG and is presumed related to a reactive marrow. c are coronal and sagittal images of a patient with increased uptake in the medial aspects of both knee joints which is much more marked with ¹⁸F-FDG, compared to ¹⁸F-GE-180. The ¹⁸F-GE-180 images also demonstrate increased muscle and marrow uptake. The scale on all figures is SUV (g/mL)