title: Quantitative perfusion analysis of malignant liver tumors:  dynamic computed tomography and contrast-enhanced ultrasound.
abstract: OBJECTIVE
  To prospectively analyze the correlation between quantitative parameters of perfusion derived from dynamic contrast-enhanced CT (DCE-CT) and contrast-enhanced ultrasound (DCE-US) in patients with malignant liver tumors.
  
  
  METHODS
  Thirty patients (mean age: 59.4 ± 12.3 years) with primary malignant liver tumors or hepatic metastases of various origin underwent DCE-CT (4D spiral mode, scan range, 14.8 cm; 15 scans; cycle time, 3 seconds) and DCE-US (low mechanical index, <0.1, 2.4 mL microbubbles). DCE-CT and DCE-US images were evaluated by 2 radiologists regarding quantitative perfusion parameters including arterial liver perfusion (ALP), portal-venous perfusion (PVP), and total perfusion (P = ALP + PVP) from DCE-CT, as well as blood inflow velocity (B) and the normalized slope within the calculation range (CVan) from DCE-US.
  
  
  RESULTS
  Quantitative assessment was possible with DCE-CT in 12/30 (40%) patients before and in all patients after automated motion correction. With DCE-US, quantitative assessment could not be performed in 9/30 (30.0%) patients due to respiratory motion. Interreader agreements for quantitative perfusion analysis were good with DCE-CT (r = 0.640-0.892, each P < 0.001) and DCE-US (r = 0.761-0.909, each P < 0.001). Moderate significant correlations were found between the perfusion parameters from DCE-CT (P, ALP) and DCE-US (B, CVan) (r = 0.446-0.621, each P < 0.05). No significant correlations were found between PVP from CT and perfusion parameters from DCE-US (B, CVan; each P = nonsignificant).
  
  
  CONCLUSIONS
  Quantitative evaluation of DCE-CT data was feasible in all patients after automated motion correction, whereas DCE-US data could not be quantitatively evaluated in 30% of patients due to respiratory motion and lack of motion correction software. Quantitative arterial perfusion analysis showed moderate significant correlations for blood flow parameters among modalities.
authors.affiliation: Department of Radiology, University Hospital Zurich, Switzerland.
authors.forename: Robert
authors.initials: R
authors.lastname: Goetti
authors.forename: Caecilia S
authors.initials: CS
authors.lastname: Reiner
authors.forename: Alexander
authors.initials: A
authors.lastname: Knuth
authors.forename: Ernst
authors.initials: E
authors.lastname: Klotz
authors.forename: Frank
authors.initials: F
authors.lastname: Stenner
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Samaras
authors.forename: Hatem
authors.initials: H
authors.lastname: Alkadhi
mesh_terms: D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D010743:Phospholipids; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*
chemical_list: D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride