title: [The value of different spiral CT phases in the detection of liver metastases].
abstract: OBJECTIVE
  To assess the value of the non-contrast phase (NCP), hepatic-arterial phase (HAP) and portal-venous phases (PVP) for the detection of liver metastases by spiral CT.
  
  
  METHODS
  In order to detect liver metastases, 119 patients (58 women, 61 men; mean age: 62 years) underwent triphasic spiral CT (8 mm collimation, 12 mm table increment/rotation, 7 mm reconstruction increment). NCP, HAP (20 s delay) and PVP (70 s delay) scans were acquired (contrast medium injection rate: 4 ml/s). CT analysis comprised independent evaluation of the three scan series for detection and conspicuity of liver metastases (conspicuity score: 0 = not visible, 1 = barely visible, 2 = clearly visible, 3 = distinctly visible).
  
  
  RESULTS
  In 83 of the 119 patients, 478 liver metastases were detected (110 hypervascular and 368 hypovascular lesions). 285 (60 %) metastases were detected on NCP scans. Significantly more lesions were seen on HAP (n = 375, 78 %) and on PVP (n = 428, 90 %). No lesion was detected on NCP studies alone. For all detected metastases, mean conspicuity was 1.2 +/- 0.4 on NCP, 1.8 +/- 0.8 on HAP and 2.2 +/- 0.8 PVP. Hypervascular lesions were best seen on HAP with a conspicuity score of 2.0 +/- 0.8 versus 1.3 +/- 0.5 on NCP and 1.5 +/- 0.8 on PVP. Hypovascular lesions reached the highest conspicuity on PVP with 2.4 +/- 0.8 versus 1.2 +/- 0.4 on NCP and 1.7 +/- 0.7 on HAP.
  
  
  CONCLUSIONS
  For detection of liver metastases with spiral CT, contrast series seem to be sufficient. For tumors likely to seed hypervascular metastases, HAP scans should be applied in addition to the PVP.
authors.affiliation: Universitätsklinik für Radiologie, LKH Graz, Osterreich, Germany. rupert.portugaller@kfunigraz.ac.at
authors.forename: H R
authors.initials: HR
authors.lastname: Portugaller
authors.forename: R
authors.initials: R
authors.lastname: Stacher
authors.forename: G
authors.initials: G
authors.lastname: Komaz
authors.forename: M
authors.initials: M
authors.lastname: Aschauer
authors.forename: K A
authors.initials: KA
authors.lastname: Hausegger
authors.forename: D H
authors.initials: DH
authors.lastname: Szolar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003627:Data Interpretation, Statistical; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media