title: Impairment of change in diameter of the hepatic portion of the inferior vena cava: a sonographic sign of liver fibrosis or cirrhosis.
abstract: OBJECTIVE
  We propose a new sonographic technique for detecting parenchymal stiffness of the liver. This technique measures the physiologic change in the diameter of the hepatic inferior vena cava (IVC). The hepatic portion of the IVC is extensively attached to the hepatic parenchyma so that changes in diameter of the venous lumen could not occur without changes in the shape of the surrounding parenchyma. Therefore, increased parenchymal stiffness due to cirrhosis or fibrosis may result in an impaired change in venous diameter.
  
  
  METHODS
  Thirty patients with histologically proven cirrhosis and 30 patients with normal livers were examined. A commercial ultrasound system was used in conjunction with a convex probe at a center frequency of 4.0 MHz. The major axis of the IVC was measured during normal breathing. The patients were then requested to take a deep breath to produce negative intrathoracic pressure, and the same measurement as that during normal breathing was repeated immediately.
  
  
  RESULTS
  In the normal liver group, the maximal diameter of the vena cava was 2.35 +/- 0.34 cm (mean +/- SD), and this was reduced by 1.30 +/- 0.67 cm (range, 0.4-2.85 cm) during deep inspiration. In the cirrhotic patient group, the maximal diameter was 1.74 +/- 0.35 cm, and this was reduced by 0.03 +/- 0.09 cm (range, 0.0-0.4 cm) (P < .0001).
  
  
  CONCLUSIONS
  The physiologic change in the diameter of the hepatic portion of the IVC enhanced by deep respiration may reflect the stiffness of hepatic parenchyma.
authors.affiliation: Department of Surgery, National Hospital Organization Chushin Matsumoto National Hospital, 811 Kotobuki-toyooka, Matsumoto, Nagano 3900021, Japan. kitamurh@cmatumoto.hosp.go.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitamura
authors.forename: Chujiro
authors.initials: C
authors.lastname: Kobayashi
mesh_terms: D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging* / Q000473:pathology*