===Choice of modality===
*'''[[MRI of rectal cancer]]''' is generally mandatory for both primary staging and restaging of a known rectal cancer.<ref name="Beets-TanLambregts2017"/>
*'''Endorectal ultrasound (EUS)''' is indicated for:<ref name="Beets-TanLambregts2017"/>
:* Staging for early tumours considered for local excision
:* Superior diagnostic performance for differentiating T1 from T2 tumors