Fig. 4

a-i. Patient in the neoadjuvant treatment group with mucinous rectal cancer. a-c: Staging FDG-PET/MRI before chemoradiotherapy. Anatomically matched nodal structure measuring 6.3 mm in short axis seen in a) transaxial T2-weighted sequence perpendicular to the tumour, b) FDG-PET/MRI with a T2-weighted MR sequence showing increased metabolic activity (above background) in the same nodal structure, and c) Static 3D MAC PET image. d-f: Restaging FDG-PET/MRI after chemoradiotherapy in the same patient. The selected and anatomically matched nodal structure now measures 2.9 mm in the short axis, seen in d) transaxial T2-weighted sequence perpendicular to the tumour and e) FDG-PET/MRI with a T2-weighted MR sequence, with no residual metabolic activity, and f) Static 3D MAC PET image. g-i: The same nodal structure in g) transaxial T1-weighted sequence MRI of the surgical specimen, h) in the finding-by-finding description using the photographed slices arrayed numerically, and i) at microscopy, using hematoxylin & eosin stain at 5x magnification where no residual malignant growth was seen. *Including the two nodal structures that proved to be EMVI at histopathology analysis. EMVI was not measured to size and is, therefore, not accounted for in the histopathological nodal structures