title: Imaging study of early hepatocellular carcinoma: usefulness of gadoxetic acid-enhanced MR imaging.
abstract: OBJECTIVE
  To describe imaging findings of early hepatocellular carcinoma (HCC) at gadoxetic acid-enhanced magnetic resonance (MR) imaging, dynamic contrast material-enhanced computed tomography (CT), CT during arterial portography (CTAP), and CT during hepatic arteriography (CTHA) and to compare the diagnostic performance of each modality for small (≤ 2 cm) HCC.
  
  
  METHODS
  The institute ethics committee deemed study approval unnecessary. One hundred eight resected small lesions in 64 patients were diagnosed as a dysplastic nodule (DN) (n = 12), progressed HCC (n = 66), or early HCC (n = 30). All but two patients underwent all imaging examinations. The imaging characteristics of the lesions with each modality were determined. To evaluate the diagnostic performance of the modalities, two radiologists graded the presence of HCC with use of a five-point confidence scale. The area under the receiver operating characteristic curve (A(z)), sensitivity, and specificity of each modality were compared.
  
  
  RESULTS
  The imaging features that are statistically significant for differentiating an early HCC from a DN include fat-containing lesions at dual-echo T1-weighted MR imaging (seen in 16 of the 30 early HCCs and none of the DNs), low attenuation at unenhanced CT (seen in 13 of the 30 early HCCs and none of the DNs), low attenuation at CTAP (seen in 11 of the 30 early HCCs and none of the DNs), and low signal intensity at hepatocyte phase gadoxetic acid-enhanced MR imaging (seen in 29 of the 30 early HCCs and none of the DNs). The diagnostic performance of gadoxetic acid-enhanced MR imaging (A(z), 0.98 and 0.99) was significantly greater than that of contrast-enhanced CT (A(z), 0.87) and CTHA-CTAP (A(z), 0.85 and 0.86) owing to its significantly higher sensitivity (P < .001).
  
  
  CONCLUSIONS
  Gadoxetic acid-enhanced MR imaging is the most useful imaging technique for evaluating small HCC, including early HCC.
authors: Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo-shi, Yamanashi 409-3898, Japan.
authors: Katsuhiro
authors: K
authors: Sano
authors: Tomoaki
authors: T
authors: Ichikawa
authors: Utaroh
authors: U
authors: Motosugi
authors: Hironobu
authors: H
authors: Sou
authors: Ali M
authors: AM
authors: Muhi
authors: Masanori
authors: M
authors: Matsuda
authors: Masayuki
authors: M
authors: Nakano
authors: Michiie
authors: M
authors: Sakamoto
authors: Tadao
authors: T
authors: Nakazawa
authors: Masami
authors: M
authors: Asakawa
authors: Hideki
authors: H
authors: Fujii
authors: Takatoshi
authors: T
authors: Kitamura
authors: Nobuyuki
authors: N
authors: Enomoto
authors: Tsutomu
authors: T
authors: Araki
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D016009:Chi-Square Distribution; D003287:Contrast Media; D042241:Early Diagnosis; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007472:Iohexol; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D007472:Iohexol; D019786:Gadolinium DTPA