title: CT colonography after metallic stent placement for acute malignant colonic obstruction.
abstract: OBJECTIVE
  To evaluate the feasibility of using computed tomographic (CT) colonography for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by colorectal cancer.
  
  
  METHODS
  Institutional review board approval was obtained, and patient informed consent was waived. Fifty patients (mean age +/- standard deviation, 58.5 years +/- 11.7), who demonstrated no postprocedural complication after successful placement of self-expandable metallic stents to treat acute colon obstruction caused by cancer, underwent CT colonography 1-43 days (median, 5 days) after stent placement. CT colonography was performed after cathartic preparation by using magnesium citrate (n = 20) or sodium phosphate (n = 3), combined with oral bisacodyl, or by using polyethylene glycol (n = 27). Fecal/fluid tagging was achieved by using 100 mL of meglumine diatrizoate. The colon was distended by means of pressure-monitored CO(2) insufflation. The sensitivity and specificity of CT colonography in evaluating the colon proximal to the stent and CT colonography-related complications were assessed. The 95% confidence intervals (CIs) were calculated for proportional data.
  
  
  RESULTS
  Per-lesion and per-patient sensitivities of CT colonography for lesions 6 mm or larger in diameter in the colon proximal to the stent were 85.7% (12 of 14 lesions; 95% CI: 58.8%, 97.2%) and 90% (nine of 10 patients; 95% CI: 57.4%, 99.9%), respectively. CT colonography depicted all synchronous cancers (two lesions) and advanced adenomas (five lesions). Per-patient specificity for lesions 6 mm and larger in the proximal colon was 85.7% (18 of 21 patients; 95% CI: 64.5%, 95.9%). CT colonography did not generate any false diagnosis of synchronous cancer. False-positive findings at CT colonography did not result in a change in surgical plan for any patients. No CT colonography-associated stent dislodgment/migration or colonic perforation occurred in any patient (95% CI: 0%, 6.2%).
  
  
  CONCLUSIONS
  CT colonography is a safe and useful method for preoperative examination of the proximal colon after metallic stent placement in patients with acute colon obstruction caused by cancer. (c) RSNA, 2010.
authors.affiliation: Department of Radiology and Research Institute of Radiology and Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-Dong, Songpa-Gu, Seoul 138-040, Korea.
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Cha
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Park
authors.forename: Seung Soo
authors.initials: SS
authors.lastname: Lee
authors.forename: Jin Cheon
authors.initials: JC
authors.lastname: Kim
authors.forename: Chang Sik
authors.initials: CS
authors.lastname: Yu
authors.forename: Seok-Byung
authors.initials: SB
authors.lastname: Lim
authors.forename: Sang Nam
authors.initials: SN
authors.lastname: Yoon
authors.forename: Yong Moon
authors.initials: YM
authors.lastname: Shin
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Kim
authors.forename: Hyun Kwon
authors.initials: HK
authors.lastname: Ha
mesh_terms: D000208:Acute Disease; D000368:Aged; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008670:Metals; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D012015:Reference Standards; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015607:Stents
chemical_list: D003287:Contrast Media; D008670:Metals; D007472:Iohexol; C038192:iopromide