title: Relationship between CT volumetric measurements and Doppler perfusion indices in gastrointestinal liver metastasis.
abstract: OBJECTIVE
  This study investigated how the volume of hepatic metastatic lesions can affect liver haemodynamics and whether these perfusion parameters may help to differentiate benign and malignant liver lesions.
  
  
  METHODS
  The Doppler perfusion index (DPI the ratio of arterial to total liver blood flow) was measured in 46 patients aged 29-83 years, exhibiting up to four focal hyperechoic liver lesions at ultrasound examination. They comprised histopathologically proven liver metastasis of colorectal (19 cases) and gastric (10 cases) adenocarcinoma without local recurrence at the site of the previously resected primary tumour, along with 17 subjects with haemangioma. All patients underwent volumetric assessment using multislice computed tomography to calculate total volume of hepatic lesions.
  
  
  RESULTS
  The mean DPI of patients with colorectal (36 ± 2 %) and gastric (39 ± 6 %) metastasis was significantly higher than those with haemangioma (14 ± 2 %) (both p < 0.001), whereas metastatic groups did not exhibit any difference in terms of mean DPI. Statistically significant correlations were found between DPI values and calculated total volume of lesions in patients with colorectal and gastric metastasis (r = 0.55, p = 0.01 and r = 0.85, p = 0.002, respectively) while this correlation was not demonstrated in the haemangioma group. Simple linear regression analysis revealed that every 1 cm(3) increment in total volume of metastatic lesions increased DPI by 0.2 % [95 % confidence interval (CI) 0.1-0.3, p = 0.001].
  
  
  CONCLUSIONS
  Doppler perfusion index alterations are directly correlated with total volume of metastatic deposits, and DPI measurement can be a valuable method to distinguish haemangioma from hyperechoic colorectal and gastric metastatic lesions.
authors.affiliation: Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences, North Kargar Ave., Tehran, 14114, Iran, amir.radmard@gmail.com.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Radmard
authors.forename: Alireza
authors.initials: A
authors.lastname: Abrishami
authors.forename: Ali
authors.initials: A
authors.lastname: Gholamrezanezhad
authors.forename: Shadi
authors.initials: S
authors.lastname: Kolahdoozan
authors.forename: Nahid
authors.initials: N
authors.lastname: Sedighi
authors.forename: Amir Pejman Hashemi
authors.initials: AP
authors.lastname: Taheri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054893:Cone-Beam Computed Tomography; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D006439:Hemodynamics; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D018608:Ultrasonography, Doppler