Introduction: Preoperative staging by imaging

In recent decades, the role of imaging in the local staging of rectal cancer has evolved. Whereas in the past, its role has been restricted mainly to endorectal ultrasound, it has recently extended to modern imaging such as CT and MRI. This chapter on "imaging and staging" will address the two most frequently used imaging methods in rectal cancer management: endorectal ultrasound (EUS) and magnetic resonance imaging (MRI). For each, experts in the field will elaborate on how these methods can identify the relevant risk factors for local recurrence and which protocol should be used to ensure a high-quality performance. In this section, the introduction, a helicopter view is given on the role of each method, EUS and MRI, in the context of clinical decision-making and its role put in perspective of one another. The introduction finalizes with recommendations for use in clinical practice.