title: Evaluation of splenic perfusion and spleen size using dynamic computed tomography: Usefulness in assessing degree of liver fibrosis.
abstract: OBJECTIVE
  To enhance the usefulness of splenic perfusion evaluated by means of dynamic computed tomography (CT) and spleen size in assessing the degree of liver fibrosis.
  
  
  METHODS
  We retrospectively studied 133 patients who had undergone dynamic CT before hepatectomy. Fibrosis was histologically established in all. First we calculated splenic perfusion parameters K1(inflow rate constant), 1/k2(mean transit time; MTT), and K1/k2(distribution volume; Vd), using compartment model analysis. Then we compared the stage of fibrosis with splenic perfusion and spleen size (long axis, R), using the Kruskal-Wallis test and multiple comparisons. After that, we assessed the diagnostic accuracy of the combination of splenic perfusion, spleen size, age, gender, and the presence or absence of hepatitis B and hepatitis C viral infection in detecting liver fibrosis, using stepwise regression and receiver operating characteristic analysis.
  
  
  RESULTS
  Significant differences (P < 0.05) in MTT were observed in comparisons between fibrosis stages F0 and F4, between F1 and F4, and between F2 and F4. Significant differences (P < 0.05) in R were observed in comparisons between F0 and F4, and between F1 and F4. Considering the presence or absence of hepatitis B and C viral infection along with MTT and R, the areas under the receiver operating characteristic curves were 0.89 for ≥F1, 0.83 for ≥F2, 0.82 for ≥F3, and 0.82 for F4.
  
  
  CONCLUSIONS
  Splenic MTT and spleen size are helpful in assessing liver fibrosis.
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Takeshi
authors.identifier: http://orcid.org/0000-0002-3040-0625
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Akira
authors.identifier: http://orcid.org/0000-0002-4199-203X
authors.initials: A
authors.lastname: Yamada
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Komatsu
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurozumi
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Fujinaga
authors.affiliation: Diagnostic Imaging Center, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ueda
authors.affiliation: First Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Miyagawa
authors.affiliation: Department of Radiology, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Masumi
authors.initials: M
authors.lastname: Kadoya
keywords: liver fibrosis; multidetector computed tomography; perfusion; portal hypertension; spleen