title: Acute pulmonary embolism: comparison of standard axial MDCT with paddlewheel technique.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the ability of rotated paddlewheel reformations for the detection of central and peripheral pulmonary embolism (PE) compared to standard axial multi detector CT (MDCT) images.
  
  
  METHODS
  CT scans of 35 patients with PE were reviewed by three independent readers for the detection of pulmonary emboli using standard axial CT scans and reformatted paddlewheel technique. All images were evaluated in random order. MDCT examinations were performed with a collimation of 1.25 mm, a pitch of six and a reconstruction interval of 0.8mm. For each patient MIP were reformatted by using a paddlewheel arrangement with 5mm slab thickness and 5 degrees rotation. Standard of reference for PE was a consensus reading of the axial images by all three readers.
  
  
  RESULTS
  The overall sensitivity for the axial images for the three readers ranged between 91% and 96%; for paddlewheel reformations from 78% to 83%; the specificity for both methods was 98-99%. Inter- and intraobserver agreement was also higher for axial images than for paddlewheel reformations.
  
  
  CONCLUSIONS
  Comparing standard axial MDCT scans and reformatted paddlewheel images no significant difference for the detection of central PE was found, whereas for the detection of peripheral emboli standard axial images showed a significant higher percentage of detecting PE than paddlewheel reformations.
authors.affiliation: Department of Radiology, Medical University Graz, Auenbruggerplatz 9, A-8036 Graz, Austria. peter.brader@meduni-graz.at
authors.forename: Peter
authors.initials: P
authors.lastname: Brader
authors.forename: Helmut
authors.initials: H
authors.lastname: Schoellnast
authors.forename: Hannes A
authors.initials: HA
authors.lastname: Deutschmann
authors.forename: Felix
authors.initials: F
authors.lastname: Thimary
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schaffler
authors.forename: Pia
authors.initials: P
authors.lastname: Reittner
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide