An example of the missing head artefact shown as sagittal images. From left to right, low-dose CT scan as an anatomical reference through the middle of the patient's head, Astonish reconstruction, and Astonish reconstruction with a Hann filter. Both Astonish reconstructions are performed with scatter and attenuation correction. The missing head artefact is shown in the middle panel. The Hann filter recovers the head as shown in the right panel.