title: Laterally spreading tumors: limitations of computed tomography colonography.
abstract: OBJECTIVE
  To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).
  
  
  METHODS
  Patients with LSTs measuring ≥ 20 mm detected during colonoscopy were prospectively enrolled in the study. All patients underwent colonoscopy and subsequent CTC on the same day. CTC was performed using multi-detector CT without contrast in the prone and supine positions. Two radiologists blinded to the existence of LSTs read the virtual endoscopic images as well as 2-D images. LSTs were classified into granular and non-granular types based on colonoscopic appearance.
  
  
  RESULTS
  Forty-seven pathologically proven LSTs were evaluated prospectively. Histology included adenomas in 19, mucosal cancers in 19 and T1 cancers in 9. The mean diameter of the LSTs was 35.1 mm. Twenty-eight (60%) LSTs were correctly identified by CTC, and the configuration was similar to the colonoscopic appearance in most cases. Detection rate for the granular type was significantly higher than that for the non-granular type (71% vs 31%, P = 0.013). Detection rate of adenomas was significantly lower than mucosal cancers (32% vs 79%, P = 0.008) and T1 cancers (32% vs 78%, P = 0.042).
  
  
  CONCLUSIONS
  The detection rate of LSTs by CTC, particularly the non-granular type was not acceptable. Practitioners should be aware of the relatively low detection rate when using CTC.
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Togashi
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Utano
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Kijima
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Hisanaga
authors.initials: H
authors.lastname: Horie
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Keijirou
authors.initials: K
authors.lastname: Sunada
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Lefor
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Hideharu
authors.initials: H
authors.lastname: Sugimoto
authors.affiliation: Kazutomo Togashi, Kenichi Utano, Department of Coloproctology, Aizu Medical Center, Fukushima Medical University, Aizuwakmatsu-city, Fukushima 969-3492, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Yasuda
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D056888:Patient Positioning; D011237:Predictive Value of Tests; D016684:Prone Position; D011446:Prospective Studies; D015203:Reproducibility of Results; D016683:Supine Position; D047368:Tumor Burden
keywords: Advanced lesion; Colon neoplasm; Computed tomography colonography; Detection rate; Flat adenoma; Laterally spreading tumor