title: Gastric Cancer: Preoperative TNM Staging With Individually Adjusted Computed Tomography Scanning Phase.
abstract: OBJECTIVE
  The aim of this study was to evaluate test bolus scan technology on preoperative diagnostic performance, vascular enhancement, and artery visualization for gastric cancer.
  
  
  METHODS
  The institutional review board approved this study. Fifty-four patients in protocol 1 were resigned to a fixed delay time scan method, and their images were obtained in the late arterial phase (AP) and portal venous phase (PP), with start delays of 40 and 70 seconds, respectively. Fifty-six patients in protocol 2 had undergone the test bolus method first and received the time to peak enhancement of the aorta. Their images were obtained in the AP and PP with start delays in the time to peak enhancement and 20 seconds after the AP, respectively. Two radiologists performed consensus interpretation of the preoperative TNM staging, vascular enhancement, tumor contrast-to-noise ratio (CNR) and artery visualization between the 2 protocols.
  
  
  RESULTS
  There is no significant difference in the T, N, and M staging diagnostic accuracy between the protocols (P = 0.41, P > 0.99, and P = 0.34, respectively). For serosa-negative (T1, T2, and T3) tumors, the diagnostic accuracy obtained with protocol 2 was superior to that obtained with protocol 1 (P = 0.04). Protocol 2 was superior for perigastric vessel enhancement (left gastric artery, right gastroepiploic artery, and splenic artery; P < 0.001, P < 0.001, and P = 0.001, respectively). The stomach-to-tumor CNR during the PP of protocol 2 was significantly higher than that during either the AP or PP of protocol 1 (P = 0.004 and P = 0.001, respectively). The mean rankings of the artery visualization were significantly higher with protocol 2 than with protocol 1 (P < 0.001).
  
  
  CONCLUSIONS
  The dual-phase scan with test bolus technology could improve the tumor CNR and had high staging accuracy for serosa-negative tumors as well as high perigastric artery enhancement, yielding satisfactory artery visualization for diagnosis.
authors.affiliation: From the *Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai; †Department of Radiology, the First Affiliated Hospital of Soochow University, Suzhou; and ‡Siemens Ltd. China; and §Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.
authors.forename: Cen
authors.initials: C
authors.lastname: Shi
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Yan
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Liu
authors.forename: Zilai
authors.initials: Z
authors.lastname: Pan
authors.forename: Weiwu
authors.initials: W
authors.lastname: Yao
authors.forename: Fuhua
authors.initials: F
authors.lastname: Yan
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011169:Portal Vein / Q000000981:diagnostic imaging; D011300:Preoperative Care; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide