title: Magnetic resonance imaging of rectal cancer: staging and restaging evaluation.
abstract: Magnetic resonance imaging is used to non-invasively stage and restage rectal adenocarcinomas. Accurate staging is important as the depth of tumor extension and the presence or absence of lymph node metastases determines if an individual will undergo preoperative neoadjuvant chemoradiation. Accurate description of tumor location is important for presurgical planning. The relationship of the tumor to the anal sphincter in addition to the depth of local invasion determines the surgical approach used for resection. High-resolution T2-weighted imaging is the primary sequence used for initial staging. The addition of diffusion-weighted imaging improves accuracy in the assessment of treatment response on restaging scans. Approximately 10%-30% of individuals will experience a complete pathologic response following chemoradiation with no residual viable tumor found in the resected specimen at histopathologic assessment. In some centers, individuals with no residual tumor visible on restaging MR who are thought to be at high operative risk are monitored with serial imaging and a "watch and wait" approach in lieu of resection. Normal rectal anatomy, MR technique utilized for staging and restaging scans, and TMN staging are reviewed. An overview of surgical techniques used for resection including newer, minimally invasive endoluminal techniques is included.
authors.affiliation: Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA. courtney.coursey@emoryhealthcare.org.
authors.forename: Courtney C
authors.initials: CC
authors.lastname: Moreno
authors.affiliation: Department of Surgery, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Sullivan
authors.affiliation: Department of Medical Imaging, The University of Arizona School of Medicine, Tucson, AZ, 85724, USA.
authors.forename: Bobby T
authors.initials: BT
authors.lastname: Kalb
authors.affiliation: Department of Pathology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: Russell G
authors.initials: RG
authors.lastname: Tipton
authors.affiliation: Department of Pathology, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: Krisztina Z
authors.initials: KZ
authors.lastname: Hanley
authors.affiliation: Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: Hiroumi D
authors.initials: HD
authors.lastname: Kitajima
authors.affiliation: Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: W Thomas
authors.initials: WT
authors.lastname: Dixon
authors.affiliation: Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Votaw
authors.affiliation: Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: John N
authors.initials: JN
authors.lastname: Oshinski
authors.affiliation: Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, 30322, USA.
authors.forename: Pardeep K
authors.initials: PK
authors.lastname: Mittal
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000473:pathology*; D012007:Rectum / Q000473:pathology; D015203:Reproducibility of Results
keywords: Magnetic resonance imaging; Rectal adenocarcinoma; Rectal cancer staging