title: Objective measurement of motion in patients undergoing spiral CT examinations.
abstract: OBJECTIVE
  To develop and evaluate an objective measurement of patient motion during spiral computed tomography (CT).
  
  
  METHODS
  An acrylic rod was attached along the length of the torso in 109 patients (56 women, 53 men; age range, 21-79 years; mean age, 51 years) who underwent abdominal spiral CT examinations. Subjective evaluation of motion was graded on a five-point scale by two radiologists. Objective measurements of motion were determined by means of computer reconstruction of the rod in three dimensions and calculation of the deviation of the rod from its estimated position in the motionless state with time.
  
  
  RESULTS
  Complete data were available in 98 patients. Subjective and objective measurements of patient motion showed a moderately high Spearman correlation coefficient of .49 (P < .001). The correlation between either observer and objective measurements was similar to the correlation between one observer and the other.
  
  
  CONCLUSIONS
  This objective technique for assessing patient motion correlated well with subjective methods and may be useful in evaluating scanning parameters that may affect patient motion and hence scan quality.
authors.affiliation: Department of Radiology, Indiana University School of Medicine, Indianapolis 46202-5253, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Stockberger
authors.forename: Y
authors.initials: Y
authors.lastname: Liang
authors.forename: J A
authors.initials: JA
authors.lastname: Hicklin
authors.forename: J L
authors.initials: JL
authors.lastname: Wass
authors.forename: W T
authors.initials: WT
authors.lastname: Ambrosius
authors.forename: K K
authors.initials: KK
authors.lastname: Kopecky
mesh_terms: D016477:Artifacts; D003287:Contrast Media; D003973:Diatrizoate; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D009068:Movement; D011860:Radiography, Abdominal; D012119:Respiration; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
chemical_list: D003287:Contrast Media; D003973:Diatrizoate; D007472:Iohexol