title: Small hepatic lesions found on single-phase helical CT in patients with malignancy: diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) MR imaging using a half-fourier acquisition single-shot turbo spin-echo (HASTE) sequence.
abstract: OBJECTIVE
  To evaluate the diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) imaging using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence in combination with T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequences for small hepatic lesions found on CT in patients with malignancy.
  
  
  METHODS
  This study included 48 patients with extrahepatic malignancy who underwent both CT and MR examinations. There were a total of 112 small hepatic lesions (73 cysts and 39 liver metastases, <2 cm in diameter) that showed low attenuation on enhanced CT. Three radiologists independently reviewed the CT and MR (FLAIR-HASTE and T2-weighted FSE) images and assigned a confidence level to their evaluation (cyst or metastasis) on a five-point scale.
  
  
  RESULTS
  All three reviewers were significantly better able (P < 0.05) to differentiate small hepatic cyst from liver metastasis with combined FLAIR-HASTE and T2-weighted FSE images (Az values = 0.997-0.999) than with CT (0.917-0.932). The mean values of sensitivity, specificity, and accuracy were significantly higher (P < 0.001) for T2-weighted FSE with FLAIR-HASTE (96.6%, 96.8%, and 96.7%, respectively) than for CT (76.9%, 61.6%, and 67.3%, respectively). A confident diagnosis was rendered in 12 of 112 lesions (10.7%) on the basis of CT, and this rate increased to 83 of 112 (74.1%) on the basis of T2-weighted FSE and FLAIR-HASTE imaging.
  
  
  CONCLUSIONS
  FLAIR-HASTE is considered to be an effective sequence for differentiating hepatic cysts from liver metastases without the use of a contrast agent. With FLAIR-HASTE one can confidently diagnose small hepatic lesions found on CT in patients with a malignancy.
authors.affiliation: Department of Radiology, Yamaguchi University School of Medicine, Ube, Yamaguchi, Japan. kjh-sasaki@mx.tiki.ne.jp
authors.forename: Katsumi
authors.initials: K
authors.lastname: Sasaki
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujita
authors.forename: Ayame
authors.initials: A
authors.lastname: Shimizu
authors.forename: Masayasu
authors.initials: M
authors.lastname: Yasui
authors.forename: Minoru
authors.initials: M
authors.lastname: Hayashida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tanabe
authors.forename: Naofumi
authors.initials: N
authors.lastname: Matsunaga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007479:Iopamidol; D008107:Liver Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed
chemical_list: D003287:Contrast Media; D007479:Iopamidol