title: Vascular encasement by pancreatic cancer: correlation of CT findings with surgical and pathologic results.
abstract: OBJECTIVE
  The purpose of this study was to correlate thin-slice high-resolution helical CT findings of arterial and venous involvement in pancreatic cancers with surgical and histopathologic results.
  
  
  METHODS
  Forty-eight patients with pancreatic cancer underwent preoperative thin-slice high-resolution helical CT, followed by surgical dissection of the pancreatic vessels during curative or palliative surgery. Major vessels running within 1 cm from the tumor margin were evaluated. CT appearance was graded on a 0-4 scale (0: none, 1: <24%, 2: 25-49%, 3: 50-74%, 4: 75-100%) by circumferential contiguity of tumor to vessels. Resected specimens were available from 26 patients.
  
  
  RESULTS
  Surgical correlation of CT findings was available in 89 veins and 83 arteries, and both surgical and histologic correlation was available for 42 veins and 29 arteries. At surgical observation, 29 of 35 veins (82.9%) evaluated as CT grade 3 or 4 were found to be involved, whereas only 18 of 30 arteries (60%) evaluated as CT grade 3 or 4 were proved to be involved. On microscopic observation, tumor invasion to the portal venous systems was confirmed in 15 of 42 (35.7%) vessels, and this invasion was depicted as from CT grades 1 to 4. In arteries, tumor invasion was seen in 3 of 29 vessels (10.3%), all of which were graded as 3 or 4 by CT.
  
  
  CONCLUSIONS
  The grading system of vascular invasion should differ between arteries and veins. Involvement of the venous system exceeding one-half circumference of the vessels (grade 3 or 4) was suggestive of vascular invasion; however, this criterion was not always satisfactory for the evaluation of tumor invasion in the arterial system.
authors.affiliation: Department of Radiology, Kumamoto University School of Medicine, Japan. yosiharu@dd.iij4u.or.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nakayama
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: M
authors.initials: M
authors.lastname: Kadota
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Kanemitsu
authors.forename: T
authors.initials: T
authors.lastname: Hiraoka
authors.forename: M
authors.initials: M
authors.lastname: Hirota
authors.forename: M
authors.initials: M
authors.lastname: Ogawa
authors.forename: M
authors.initials: M
authors.lastname: Takeya
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010179:Pancreas / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D011169:Portal Vein / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed