title: Value of 3-dimensional CT virtual anatomy imaging in complex foreign body retrieval from soft tissues.
abstract: OBJECTIVE
  To investigate the value of 3-dimensional (3D) CT virtual anatomy imaging (VAI) in the complex foreign body (FB) retrieval of the soft tissues.
  
  
  METHODS
  Four hundred and seventy-five patients with radiopaque FB(s) diagnosed by radiograph underwent contrast-enhanced 3D CT examination. VAI was reconstructed by volume-rendering opacity software, by sliding down the lowest threshold from -600 to 100 HU. The imaging was grouped into three groups: A (axial and multi-planar reformation [MPR] images), B (standard 3D imaging with axial and MPR images), and C (VAI with axial and MPR images). They were analyzed to reveal the type, size, number, location, complications, and the interventional removability of the object, with the comparisons in the management and clinical outcomes on the patient follow-up studies. The data were subjected to chi-square tests, with p value < 0.05 indicating significant statistical difference.
  
  
  RESULTS
  The FB shape, size, number, site distribution and vessels around FB, as well as the FB-associated vascular complications and the FB interventional removability were assessed more accurately in Group C than in Group B or Group A (p < 0.005). There was no significant difference in disclosing the type and depth of the FB among the three groups (p > 0.75). On the basis of the 3D CT, especially the enhanced 3D CT VAI, the followings were processed: the recommendation of interventional removal in 286 (60.47%) and non-intervention in 187 (39.53%) of the 473 patients with soft-tissue FB(s); in 352 (56.50%) of the 623 radiopaque FBs patients, 258 (54.55%) patients accurately detected on 3D CT and the successful removal by intervention (343 FBs) or surgery (9 FBs) without any sequela; and 215 (45.45%) patients with 271 FBs lost in the follow-up, with their departure from the hospital.
  
  
  CONCLUSIONS
  The 3D CT, especially 3D enhanced CT VAI, has great incremental value in further diagnosis and management of complex FB extraction from soft tissues.
authors.affiliation: Department of Radiology, Shanghai Eighth People's Hospital, Shanghai 200235, China.
authors.forename: Xiu-Jun
authors.initials: XJ
authors.lastname: Yang
authors.forename: Guang-Fu
authors.initials: GF
authors.lastname: Xing
authors.forename: Chang-Wen
authors.initials: CW
authors.lastname: Shi
authors.forename: Wei
authors.initials: W
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D005547:Foreign Bodies / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D014584:User-Computer Interface
chemical_list: D003287:Contrast Media; D007472:Iohexol
keywords: Foreign body; Image processing, Computer-assisted; Interventional radiology; Regional anatomy; Tomography, X-ray computer