title: Accelerated dynamic MR imaging with a parallel imaging technique for hypervascular hepatocellular carcinomas: usefulness of a test bolus in examination and subtraction imaging.
abstract: OBJECTIVE
  To assess the impact of the accelerated dynamic MR imaging (ADMRI) approach using parallel imaging for detecting hypervascular hepatocellular carcinomas (HCCs) and to evaluate the usefulness of a test bolus in examination and subtraction imaging in this setting.
  
  
  METHODS
  Thirty patients with 135 HCCs underwent ADMRI using a two-dimensional gradient-recalled echo sequence with parallel imaging. Seventeen patients were evaluated without a test bolus and 13 patients with a test bolus. The detectability of HCCs was calculated between the groups with and without a test bolus. ADMRI was evaluated regarding the signal-to-noise ratio (SNR) of the lesion and the liver, the contrast-to-noise ratio (CNR) of the lesion vs. the liver, and the feasibility of subtraction images.
  
  
  RESULTS
  ADMRI with and without a test bolus had almost equal sensitivity (92.5% and 92.6%). No significant difference was seen in the SNR of lesions and the CNR of lesions vs. livers between both groups. With a test bolus, ADMRI could depict the peak enhancement of nodules on the 2nd or 3rd dynamic phases and optimized the timing of peak lesion enhancement. Subtraction images could be obtained regarding minimal slice misregistration.
  
  
  CONCLUSIONS
  ADMRI had high detectability of HCCs with and without a test bolus.
authors.affiliation: Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yoshioka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Saida
authors.forename: Yuji
authors.initials: Y
authors.lastname: Itai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed