title: Usefulness of hydrogel-CT for detecting and staging of rectosigmoid colon cancer.
abstract: OBJECTIVE
  To demonstrate the usefulness of hydrogel-CT for detecting and staging of rectosigmoid colon cancer.
  
  
  METHODS
  Fifty-four patients with rectosigmoid colon cancers underwent routine CT without (n=27) and with (n=27) rectum distension using a sonographic gel. Rectum distensibility and tumor visualization were evaluated. T and N stages on CT independently recorded by two radiologists were correlated with pathologic staging. Staging accuracies were compared using Fisher's exact test. Diagnostic performances in differentiating <T3 from ≥T3 and N0 from ≥N1 were evaluated using areas under the receiver operating characteristic curves (AZ).
  
  
  RESULTS
  Rectum distensibility (3.52) and tumor visualization (3.70) were significantly more scored in the distended group than in the control group (1.44 and 2.04) (P<0.0001). Pathologic and CT staging were more correlated in the distended group in both reviewers. Accuracy for staging was higher in the distended group (T: 50-85.2%/N: 59.3-92.6%) than in the control group (T: 45.5-62.5%/N: 33.3-59.3%) without statistical significance except N staging for reviewer 2 (P=0.0091). AZ values for T and N staging in the distended group (T: 0.827-0.989/N: 0.858-0.980) were also higher than in the control group (T: 0.817-0.907/N: 0.544-0.654).
  
  
  CONCLUSIONS
  Hydrogel-CT can provide better diagnostic performance for T and N staging of rectosigmoid colon cancer.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea.
authors.forename: Seonji
authors.initials: S
authors.lastname: Jeong
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea. Electronic address: shkim7071@gmail.com.
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea.
authors.forename: Ijin
authors.initials: I
authors.lastname: Joo
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea.
authors.forename: Su Joa
authors.initials: SJ
authors.lastname: Ahn
authors.affiliation: Department of Radiology, Seoul National University Hospital, Republic of Korea; Department of Radiology, Seoul National University College of Medicine, Republic of Korea; Department of Radiology Institute of Radiation Medicine, Seoul National University Medical Research Center, Republic of Korea.
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D009367:Neoplasm Staging; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D012007:Rectum / Q000473:pathology; D012189:Retrospective Studies; D012811:Sigmoid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
keywords: Hydrogel; Multidetector computed tomography; Neoplasm staging; Neoplasms; Rectum