title: The effect of arm positioning on timing and enhancement of intravenous contrast media at coronary computed tomography angiography.
abstract: BACKGROUND
  Adequate intravenous contrast media (CM) enhancement is crucial for evaluation of the coronary arteries.
  
  
  OBJECTIVE
  To compare the timing and enhancement of intravenous CM at coronary computed tomography angiography (CCTA) when positioning the arms in the traditional superior direction with that of positioning them in the ventral direction during the CM injection.
  
  
  METHODS
  One hundred patients were randomized into two groups. Group A (n = 50) had their arms positioned in the superior direction, resting on a head and arm support. Group B (n = 50) held their arms resting on the front panel of the computer tomography (CT) scanner. Scanning delay time was defined by test bolus technique. A total of 60 mL iodixanol, 320 mg/mL, was followed by a 50 mL saline flush at 6 mL/s. Cardiac output (CO) and heart rate (HR) were obtained before scanning. The attenuation was calculated by placing regions of interest (ROI) in ascending aorta, left atrium, and inferior vena cava.
  
  
  RESULTS
  More patients in group A compared with group B (26 versus 14) showed a higher attenuation of the left atrium in comparison to the ascending aorta (P < 0.05). Body weight (BW) and CO were significantly related to the attenuation of ascending aorta (P < 0.01).
  
  
  CONCLUSIONS
  By placing the arms in a ventral, instead of superior position the frequency of too early imaging at CCTA can be reduced.
authors.affiliation: Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden anders.svensson@ki.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Svensson
authors.affiliation: Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Cederlund
authors.affiliation: Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Aspelin
authors.affiliation: Department of Radiology, Institution of Clinical Sciences, Malmö, Faculty of Medicine, University of Lund, SE-221 00 Lund, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Nyman
authors.affiliation: Department of Clinical Science, Intervention and Technology at Karolinska Institutet, Division of Medical Imaging and Technology, Stockholm, Sweden Department of Radiology, Karolinska University Hospital in Huddinge, SE-14186 Stockholm, Sweden.
authors.forename: Torkel B
authors.initials: TB
authors.lastname: Brismar
mesh_terms: D001132:Arm; D000072226:Computed Tomography Angiography; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning
chemical_list: D003287:Contrast Media
keywords: Coronary computed tomography angiography (CCTA); body weight; cardiac output; heart rate; intravenous contrast media; stroke volume