title: Needle position during (125)I seed implantation: accurately recognized by sagittal transrectal ultrasonography [corrected].
abstract: OBJECTIVE
  The aim of this study was to assess the variation of probe rotation angles for detecting a single needle using sagittal images of transrectal ultrasonography (TRUS).
  
  
  METHODS
  A phantom study was performed. One needle was inserted through each of 10 holes of the template, and variations in the probe rotation angles for detecting the needle were measured.
  
  
  RESULTS
  The mean variation of probe rotation for detecting a single needle was 17.0 degrees (range 4 degrees -25 degrees ). Slightly broader variation was seen for the needle in holes farther away from the probe.
  
  
  CONCLUSIONS
  Probe rotation angles for detecting a single needle displayed considerable variation. Seed locations recognized on sagittal imaging by TRUS are thus indeterminate, and real-time dose calculations using TRUS for (125)I seed implantation should be used with care.
authors.affiliation: Department of Radiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, 228-8555, Japan. hishiyam@kitasato-u.ac.jp
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Ishiyama
authors.forename: Shouko
authors.initials: S
authors.lastname: Kotani
authors.forename: Takefumi
authors.initials: T
authors.lastname: Satoh
authors.forename: Mineko
authors.initials: M
authors.lastname: Uemae
authors.forename: Shiro
authors.initials: S
authors.lastname: Baba
authors.forename: Kazushige
authors.initials: K
authors.lastname: Hayakawa
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D009339:Needles; D019047:Phantoms, Imaging; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy; D012007:Rectum / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional / Q000379:methods
chemical_list: D007457:Iodine Radioisotopes