title: Contrast-enhanced MR angiography of the chest and abdomen with use of controlled apnea in children.
abstract: OBJECTIVE
  To retrospectively determine if controlled apnea improves the image quality of contrast material--enhanced magnetic resonance (MR) angiography of the chest and abdomen in children.
  
  
  METHODS
  Institutional review board approval and waiver of informed consent were obtained for this HIPAA-compliant study. The authors evaluated contrast-enhanced MR angiographic procedures performed in the chest, abdomen, or both, in 23 children (14 boys, nine girls; age range, 1 month to 8 years) who were under general anesthesia. All patients underwent mechanical ventilation with preoxygenation (100% oxygen) prior to controlled apnea during image acquisition. In control subjects, the authors assessed contrast-enhanced MR angiographic procedures performed in the chest, abdomen, or both, in 23 children (matched for age and type of study with children in the controlled apnea group; 11 boys, 12 girls; age range, 1 month to 8 years) who were under general anesthesia (n=15) or deep sedation (n=8) and were breathing spontaneously during image acquisition. MR angiograms of the chest, abdomen, or both, were assessed for image quality, motion artifacts, and vessel definition by two radiologists working in consensus with a subjective grading scale. Wilcoxon signed rank test was used to assess differences in measurements.
  
  
  RESULTS
  Image quality was rated excellent in 97% (30 of 31) of studies with controlled apnea and in 30% (nine of 31) of control studies (P<.001). Motion artifacts were absent in 97% (30 of 31) of studies with controlled apnea and 13% (four of 31) of control studies (P<.001). Vessel sharpness was rated as being significantly better on images obtained with controlled apnea (P<.05). There were no complications caused by anesthesia or sedation in either group.
  
  
  CONCLUSIONS
  Controlled apnea is highly effective in children for eliminating respiratory motion artifacts with contrast-enhanced MR angiographic studies, resulting in greatly improved image quality and spatial resolution.
authors.affiliation: Department of Radiology, Division of Diagnostic Cardiovascular Imaging, Magnetic Resonance Research Center, University of California Los Angeles, Los Angeles, CA 90095-7206, USA. rsaleh@mednet.ucla.edu
authors.forename: Roya S
authors.initials: RS
authors.lastname: Saleh
authors.forename: Swati
authors.initials: S
authors.lastname: Patel
authors.forename: Margaret H
authors.initials: MH
authors.lastname: Lee
authors.forename: M Ines
authors.initials: MI
authors.lastname: Boechat
authors.forename: Osman
authors.initials: O
authors.lastname: Ratib
authors.forename: Carla R
authors.initials: CR
authors.lastname: Saraiva
authors.forename: J Paul
authors.initials: JP
authors.lastname: Finn
mesh_terms: D000005:Abdomen / Q000473:pathology*; D001049:Apnea; D016477:Artifacts; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007103:Immobilization / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D009068:Movement; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity; D013909:Thorax / Q000473:pathology*
chemical_list: D003287:Contrast Media