title: Overestimating the size of hepatic malignancy on helical CT during arterial portography: equilibrium phase CT and pathology.
abstract: OBJECTIVE
  Overestimating the size of hepatic malignancy with helical CT during arterial portography (CTAP) can be a potential pitfall in determining liver resection area. We evaluated the prevalence and extent of overestimation of hepatic malignancy on CTAP in correlation with helical equilibrium phase CT (EPCT) and pathologic findings.
  
  
  METHODS
  CTAP and EPCT in 47 histologically proven malignant hepatic tumors [33 hepatocellular carcinomas (HCCs) and 14 metastases] in 39 patients were retrospectively studied. Nineteen tumors were resected and pathologically evaluated.
  
  
  RESULTS
  The size overestimation ratios (CTAP/EPCT) ranged from 1.02 to 1.56 (mean +/- SD 1.24 +/- 0.16) in HCC and from 1.00 to 2.48 (1.34 +/- 0.42) in metastasis. In 19 surgical specimens, the overestimation ratios (CTAP/specimen) ranged from 1.05 to 1.45 (1.20 +/- 0.13) in HCC and from 1.10 to 1.38 (1.22 +/- 0.10) in metastasis. Histopathologically, flattening of parenchymal structures (100%), atrophy of hepatic cords (95%), sinusoidal congestions (95%), fibrosis and ductular proliferation (58%), and no tumor were seen in peritumoral parenchyma corresponding to perilesional perfusion defects with CTAP.
  
  
  CONCLUSIONS
  CTAP frequently and significantly overestimates the size of malignant hepatic tumors. This phenomenon is attributable to either benign histopathological changes in the perilesional liver parenchyma caused by parenchymal compression or portal venous obstruction by malignant liver tumors or to a siphoning effect by hypervascular neoplasms.
authors.affiliation: Department of Radiology, Gifu University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kanematsu
authors.forename: H
authors.initials: H
authors.lastname: Hoshi
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Nandate
authors.forename: M
authors.initials: M
authors.lastname: Kato
authors.forename: R
authors.initials: R
authors.lastname: Yokoyama
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary; D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods; D001284:Atrophy; D001649:Bile Duct Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006498:Hepatectomy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000473:pathology; D011172:Portography / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*