title: Dual-energy CT to detect recurrent HCC after TACE: initial experience of color-coded iodine CT imaging.
abstract: OBJECTIVE
  To evaluate the feasibility of diagnosing recurrence of HCC after TACE color-coded iodine CT (CICT) based on arterial phase scans obtained by a dual-energy CT (DECT) scanner.
  
  
  METHODS
  A CICT scan was acquired from an iodine map after applying material decomposition of the liver tissue and setting a threshold attenuation level for viable tumors. Two radiologists reviewed both conventional and CICT sets in 31 patients who had a history of TACE for HCC. The performances in detecting local tumor progression (LTP) were evaluated by alternative free-response receiver operating characteristics. The rate of uncertain diagnosis and interobserver agreement of the diagnosis were explored. Additionally, the reading time and radiation dose were also investigated.
  
  
  RESULTS
  The mean figures of merit of the conventional and CICT sets for LTP were 0.818 and 0.847, respectively (p=0.459). The rate of uncertain diagnosis was significantly decreased in CICT sets (34.5% vs. 0%), and interobserver agreement was improved (k=0.527 vs. 0.718). On the CICT set, mean reading time was reduced by 49s and mean radiation dose was also decreased by 18.3% when replacing the non-contrast CT with CICT.
  
  
  CONCLUSIONS
  CICT is comparable to conventional liver CT protocol in demonstrating viable HCCs, while it allows a reduction in radiation dose.
authors.affiliation: Department of Radiology, Hanyang University College of Medicine, Hanyang University Guri Hospital, 249-1, Gyomoon-dong, Guri-si, Gyeonggi-do 471-701, Republic of Korea.
authors.forename: Jeong-Ah
authors.initials: JA
authors.lastname: Lee
authors.forename: Woo Kyoung
authors.initials: WK
authors.lastname: Jeong
authors.forename: Yongsoo
authors.initials: Y
authors.lastname: Kim
authors.forename: Soon-Young
authors.initials: SY
authors.lastname: Song
authors.forename: Jinoo
authors.initials: J
authors.lastname: Kim
authors.forename: Jeong Nam
authors.initials: JN
authors.lastname: Heo
authors.forename: Choong Ki
authors.initials: CK
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D016461:Chemoembolization, Therapeutic; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007472:Iohexol; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol