title: Esophageal cancer: evaluation with triple-phase dynamic CT--initial experience.
abstract: OBJECTIVE
  To prospectively assess which phase of a triple-phase dynamic contrast material-enhanced multi-detector row computed tomography (CT) protocol is optimal for visualization of esophageal cancer.
  
  
  METHODS
  The study was supported by the local ethical committee; all patients gave written informed consent. Thirty-one lesions in 28 consecutive patients (26 men, two women; mean age, 65 years; range, 53-87 years) with histopathologically confirmed esophageal cancer were evaluated with triple-phase dynamic CT performed at 5, 35, and 65 seconds (first arterial, second arterial, and venous phases) after attenuation of 200 HU was obtained at the descending aorta. Qualitative image analysis was performed to assess appearance and conspicuity of the tumor. Appearances of all 31 lesions were classified into three categories-not identifiable, focal enhancement with or without minimal (<1 cm) wall thickening, and focal mass lesion or obvious (>1 cm) wall thickening. Results were compared with surgical or endoscopic ultrasonographic findings. Quantitative assessment included regions-of-interest measurement of the tumor and normal esophageal wall and the difference between those measurements. A paired t test was used to determine which phase showed the highest tumor attenuation and tumor-to-normal esophageal wall attenuation differences.
  
  
  RESULTS
  At visual assessment, 30 lesions were identified in the second arterial phase. Of these 30 lesions, eight were focal enhancements; the best conspicuity was during the second arterial phase. Furthermore, seven of these eight lesions were T1 cancers. The remaining 22 lesions were enhanced masses or wall thickening. Twenty-one of these 22 tumors also showed best conspicuity in the second arterial phase. The greatest attenuation of tumors in the second arterial phase was 130.0 HU, and the difference in attenuation between tumor and normal esophageal wall was 50.6 HU in the second arterial phase, which were significantly higher than those in the other two phases (P<.01, each).
  
  
  CONCLUSIONS
  The second arterial phase of dynamic CT is the optimal phase for visualization of esophageal cancer.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, and Department of Radiology, Kyoto University Hospital, Japan.
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Umeoka
authors.forename: Takashi
authors.initials: T
authors.lastname: Koyama
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.forename: Go
authors.initials: G
authors.lastname: Watanabe
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shimada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Imamura
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging; D003287:Contrast Media; D019160:Endosonography; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging*; D004947:Esophagus / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011856:Radiographic Image Enhancement / Q000379:methods; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media