title: Differentiation of poorly differentiated colorectal adenocarcinomas from well- or moderately differentiated colorectal adenocarcinomas at contrast-enhanced multidetector CT.
abstract: OBJECTIVE
  The purpose of the study is to describe the CT findings of poorly differentiated (PD) colorectal adenocarcinoma (CRAC) compared with those of well- (WD) or moderately differentiated (MD) CRAC.
  
  
  METHODS
  One hundred and thirteen patients with pathologically proven PD (n = 26), WD (n = 35), or MD (n = 52) CRACs and who had undergone preoperative, contrast-enhanced multidetector CT (MDCT) imaging were included. Analysis of the CT findings included the morphologic and enhancement features of primary tumors and regional lymph nodes (LNs), and the presence of direct invasion, colonic obstruction, and distant metastasis. The significance of these findings was determined using the χ (2) test.
  
  
  RESULTS
  Significant features favoring the diagnosis of PD CRACs over WD or MD CRACs included their bulky shape, heterogeneous enhancement, iso- or hypoattenuation compared with that of muscle, nodular pericolic fat infiltration, regional LNs > 10 mm, and/or with iso- or hypoattenuation compared with that of muscle, and the presence of distant metastasis (P < 0.05). When at least two of these seven imaging features were used in combination, the sensitivity and specificity in the diagnosis of PD CRACs were 88% and 70%, respectively.
  
  
  CONCLUSIONS
  Using characteristic CT features, one can differentiate PD CRAC from WD or MD CRAC with a high degree of accuracy on contrast-enhanced MDCT.
authors.affiliation: Department of Radiology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Kim
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Jee Hyun
authors.initials: JH
authors.lastname: Baek
authors.forename: Sung Kyung
authors.initials: SK
authors.lastname: Moon
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide