title: Helical CT angiography of thoracic outlet syndrome: functional anatomy.
abstract: OBJECTIVE
  The objective of this study is to determine the anatomic characteristics of the thoracic outlet in symptomatic patients before and after postural maneuver.
  
  
  METHODS
  Seventy-nine symptomatic patients (61 female patients [group 1]; 18 male patients [group 2]; mean age, 38 years) underwent helical CT angiography of the thoracic apices in the neutral position and after a postural maneuver, enabling the evaluation of the functional anatomy of the musculoskeletal and arterial structures of the ipsilateral thoracic outlet.
  
  
  RESULTS
  A statistically significant difference was found between the distribution of the distances (maximum and costosubclavian) measured in the neutral position and after postural maneuver in groups 1 and 2. The median value of these distances was smaller after postural maneuver in groups 1 and 2. A statistically significant difference was found between the distribution of the distances (maximum and costosubclavian) measured in patients of group 1 with arterial stenosis and in patients of group 1 without arterial stenosis. A slight indentation of the anterior wall of the subclavian artery when it arches around the anterior scalene muscle was observed in 39 patients (64%) in group 1 and in 11 patients (61%) in group 2 in the neutral position, in 19 patients (31%) in group 1 and in six patients (33%) in group 2 after the postural maneuver. The predominant positional changes of the vascular structures were the posteroanterior displacement of the subclavian vessels observed in groups 1 and 2, the arch made by the subclavian artery above the first rib in 40 patients (66%) in group 1 and nine patients (50%) in group 2, and the posterior displacement of the axillary artery observed in 36 patients (59%) in group 1 and in 12 patients (67%) in group 2.
  
  
  CONCLUSIONS
  Helical CT shows significant narrowing of the costoclavicular space after postural maneuver in symptomatic patients.
authors.affiliation: Department of Radiology, University Center Hospital Calmette, Lille, France.
authors.forename: M
authors.initials: M
authors.lastname: Remy-Jardin
authors.forename: J
authors.initials: J
authors.lastname: Remy
authors.forename: P
authors.initials: P
authors.lastname: Masson
authors.forename: F
authors.initials: F
authors.lastname: Bonnel
authors.forename: P
authors.initials: P
authors.lastname: Debatselier
authors.forename: L
authors.initials: L
authors.lastname: Vinckier
authors.forename: A
authors.initials: A
authors.lastname: Duhamel
mesh_terms: D000293:Adolescent; D000328:Adult; D000792:Angiography; D001366:Axillary Artery / Q000000981:diagnostic imaging; D001917:Brachial Plexus / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging; D011187:Posture; D011446:Prospective Studies; D012272:Ribs / Q000000981:diagnostic imaging; D013348:Subclavian Artery / Q000000981:diagnostic imaging; D013901:Thoracic Outlet Syndrome / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed