title: Small (1.5 cm or less) liver metastases: US-guided biopsy.
abstract: OBJECTIVE
  To determine the techniques used for and the success of ultrasound (US)-guided biopsy of hepatic metastases 1.5 cm in diameter or smaller.
  
  
  METHODS
  A computer search of radiology reports identified 29 patients who underwent US-guided biopsy of 30 hepatic masses 1.5 cm in diameter or smaller suspected to be metastases. All 30 lesions were sampled for biopsy with the free-hand technique. Parameters assessed were lesion size and location, needle size, transducer type, number of passes made, cytologic or histologic analysis, and final histologic diagnosis. Biopsies were considered successful if a positive histologic diagnosis of metastasis was made.
  
  
  RESULTS
  The mean lesion diameter was 1.3 cm (range, 0.9-1.5 cm). Lesion depth was 3-9 cm (mean, 5 cm). Twenty biopsies were performed with a 22-gauge aspirating needle and analyzed cytologically. An average of 2.7 passes were made per lesion. Phased-array sector transducers were used in 23 lesions. In 28 (93%) lesions and 28 (96%) patients, an adequate specimen was obtained to establish the histologic diagnosis of metastatic disease.
  
  
  CONCLUSIONS
  US appears to be an effective guidance technique for biopsy of small liver metastases.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: W D
authors.initials: WD
authors.lastname: Middleton
authors.forename: S K
authors.initials: SK
authors.lastname: Hiskes
authors.forename: S A
authors.initials: SA
authors.lastname: Teefey
authors.forename: L D
authors.initials: LD
authors.lastname: Boucher
mesh_terms: D001707:Biopsy, Needle / Q000379:methods; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014463:Ultrasonography