title: Colorectal cancer: diagnostic potential of CT measurements of hepatic perfusion and implications for contrast enhancement protocols.
abstract: OBJECTIVE
  To assess changes in hepatic perfusion in patients with colorectal cancer with computed tomography (CT), diagnostic potential of CT perfusion measurements, and implications for design of contrast enhancement protocols.
  
  
  METHODS
  In 27 patients with colorectal cancer, arterial and portal perfusion were calculated from temporal changes in attenuation after intravenous administration of contrast material.
  
  
  RESULTS
  Arterial perfusion greater than 0.25 mL/min/mL was seen in nine (82%) of the 11 patients with overt metastases versus six (38%) of the 16 patients with no overt metastases (P < .05). Portal perfusion of 0.25 mL/min/mL or less was found in five (46%) of the patients with overt metastases versus three (19%) of the patients with no overt metastases. Follow-up imaging showed progressive metastatic disease in three patients, all of whom had decreased portal perfusion.
  
  
  CONCLUSIONS
  Increased arterial perfusion appears to be an indicator of liver metastases, whereas reduced portal perfusion may indicate progressive disease. Contrast enhancement protocols that are based on experience with normal livers may not be optimal for patients with metastases.
authors.affiliation: Centre for Functional Imaging, Wesley Research Institute & Southern X-ray Clinics, Wesley Hospital, Queensland, Australia.
authors.forename: D A
authors.initials: DA
authors.lastname: Leggett
authors.forename: B B
authors.initials: BB
authors.lastname: Kelley
authors.forename: I H
authors.initials: IH
authors.lastname: Bunce
authors.forename: K A
authors.initials: KA
authors.lastname: Miles
mesh_terms: D000368:Aged; D002985:Clinical Protocols; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008102:Liver Circulation; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D011168:Portal System / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media