title: Radiographic Detectability of Retained Neuropatties in a Cadaver Model.
abstract: BACKGROUND
  Counts are the commonest method used to ensure that all sponges and neuropatties are removed from a surgical site before closure. When the count is not reconciled, plain radiographs of the operative site are taken to determine whether the missing patty has been left in the wound. The purpose of this study was to describe the detectability of commonly used neuropatties in the clinical setting using digital technologies.
  
  
  METHODS
  Neuropatties were implanted into the anterior and posterior cranial fossae and the thoracolumbar extradural space of a mature male cadaver. Four neuropatty sizes were used: 3 × 1 in, 2 × ½ in, ½ × ½ in, and ¼ × ¼ in. Neuropatties, with size and location chosen at random, were placed in the surgical sites and anteroposterior/posterior-anterior and lateral radiographs were taken using standard portable digital radiographic equipment. Six clinicians reviewed the digital images for the presence or absence of neuropatties. The readers were not aware of the number and size of the patties that were included in each image.
  
  
  RESULTS
  The detectability of neuropatties is dependent on the size of the neuropatty's radiopaque marker and the operative site. Neuropatties measuring 2 × ½ in and 3 × 1 in were detected reliably regardless of the operative site. ¼ × ¼ in neuropatties were poorly detected by neurosurgeons and radiologists in all three operative sites. Readers of various experience and background were similar in their ability to detect neuropatties under these conditions.
  
  
  CONCLUSIONS
  Under simulated operating room conditions and using currently available neuropatties and plain radiograph imaging technology, small ¼-in and ½-in neuropatties are poorly visible/detectable on digital images.
authors.affiliation: Department of Surgery, University of British Columbia and British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
authors.forename: Wangjian Thomas
authors.initials: WT
authors.lastname: Luo
authors.affiliation: Department of Radiology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Almack
authors.affiliation: Department of Radiology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada; Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: John B
authors.initials: JB
authors.lastname: Mawson
authors.affiliation: Department of Surgery, University of British Columbia and British Columbia Children's Hospital, Vancouver, British Columbia, Canada. Electronic address: dcochrane@cw.bc.ca.
authors.forename: David Douglas
authors.initials: DD
authors.lastname: Cochrane
mesh_terms: D000328:Adult; D002102:Cadaver; D005547:Foreign Bodies / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008953:Models, Anatomic; D019635:Neurosurgical Procedures / Q000009:adverse effects* / Q000295:instrumentation; D015588:Observer Variation; D011859:Radiography; D012680:Sensitivity and Specificity; D012886:Skull / Q000000981:diagnostic imaging* / Q000601:surgery; D013131:Spine / Q000000981:diagnostic imaging* / Q000601:surgery; D015503:Surgical Sponges
keywords: Cadaver model; Foreign body; Imaging; Neuropatty; Radiopaque; Retained