title: Computed tomographic air-contrast enema imaging for presurgical examination of colon tumors: assessment with colon phantoms and in patients.
abstract: OBJECTIVE
  We investigated the mechanism of colon wall deformities in phantoms and assessed the relation between pathological T staging and wall deformity in patients using computed tomography (CT) enema imaging.
  
  
  METHODS
  We performed multidetector-row CT in mass-containing phantoms with no structural deformities and in 36 patients with colon tumors. In the phantoms, we compared images on double-contrast barium (DCB) and CT enema studies, and we compared wall deformities on CT enema studies and the actual phantom structure. In patients, we compared wall deformities on CT enema studies and T staging.
  
  
  RESULTS
  Images from CT enema and DCB studies were identical in the phantom, and all profile images showed geometrical basal indentations. In patients, the grade of deformity increased with invasion depth; and the diagnostic accuracy of T staging was 82.5%. Geometrical basal indentation and poor colon expansion were the primary reasons for overestimating T staging on CT enema imaging.
  
  
  CONCLUSIONS
  Although CT enema imaging allows reasonable diagnostic accuracy of T staging, wall deformity is thought to be consistent with tumor infiltration and other factors. We recommend evaluating T staging using not only CT enema imaging but also other techniques, such as virtual endoscopy, axial imaging, and multiplanar reformation imaging.
authors.affiliation: Department of Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka 350-1298, Japan. kayasima@pb3.so-net.ne.jp
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Kayashima
authors.forename: Fumiko
authors.initials: F
authors.lastname: Kimura
authors.forename: Kaiji
authors.initials: K
authors.lastname: Inoue
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Honda
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Ito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D004733:Enema / Q000379:methods*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D019047:Phantoms, Imaging; D011300:Preoperative Care; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed