Fig. 3

Blooming artefact. a Sagittal PD-weighted MR image of the knee in a patient with D-TGCT demonstrates multiple low signal intensity synovial lesions posterior to the PCL, along the posterior cortex of the femoral metaphysis and in the collapsed suprapatellar recess. b Sagittal T2- gradient echo weighted MR image of the knee showing blooming artefact: the low signal intensity synovial lesions containing hemosiderin increase in size and are ill defined, appearing as cloud-like dark areas. c Schematic illustration of hemosiderin signal intensities on gradient echo (GRE) weighted sequences versus T1- and T2-weighted sequences. Gradient echo images show increased size of the hemosiderin foci with irregular margins, this is called “blooming”