title: Evaluation of a high iodine delivery rate in combination with low tube current for dose reduction in pulmonary computed tomography angiography.
abstract: OBJECTIVE
  The present study evaluates the combination of a high iodine delivery rate with a low tube current-time product for pulmonary computed tomography angiography (CTA).
  
  
  METHODS
  One-hundred nineteen consecutive patients undergoing pulmonary CTA for suspected pulmonary embolism were included and imaged on a 128-row computed tomography scanner at 100 kVp using highly concentrated contrast material (85 mL Iomeprol; 400 mg iodine/mL). The protocol entailed a flow rate of 5 mL/s and 90 mAs for group A, 3.5 mL/s and 135 mAs for group B, 5 mL/s and 135 mAs for group C, and 3.5 mL/s and 90 mAs for group D. Signal-to-noise ratio and contrast-to-noise ratio (CNR) were determined for the pulmonary artery. Subjective image quality (IQ) was rated on a 5-point scale (1=nondiagnostic IQ to 5=excellent IQ).
  
  
  RESULTS
  CNR did not differ significantly between groups A (43.7±27.7), B (34.5±17.9), and C (38.9±13.8), as well as between groups B and D (29.9±11.2). CNR was higher in groups A and C than in group D (P<0.02). Subjective IQ was higher in group A than in groups B and D (P<0.05). Subjective IQ was significantly higher in group A compared with group D (P=0.026) and in group C compared with group D (P=0.007).
  
  
  CONCLUSIONS
  A high iodine delivery rate permits dose reduction in pulmonary CTA and can be recommended in patients with suspected pulmonary embolism.
authors.affiliation: *Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Duesseldorf, Duesseldorf †Bracco Imaging, Global Medical & Regulatory Affairs, Konstanz, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Heusch
authors.forename: Rotem S
authors.initials: RS
authors.lastname: Lanzman
authors.forename: Joel
authors.initials: J
authors.lastname: Aissa
authors.forename: Lars
authors.initials: L
authors.lastname: Schimmöller
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.forename: Martin
authors.initials: M
authors.lastname: Krix
authors.forename: Patric
authors.initials: P
authors.lastname: Kröpil
mesh_terms: D000368:Aged; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007455:Iodine / Q000493:pharmacokinetics; D007479:Iopamidol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008297:Male; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007455:Iodine; D007479:Iopamidol