title: MDCT angiography of the pulmonary arteries: influence of body weight, body mass index, and scan length on arterial enhancement at different iodine flow rates.
abstract: OBJECTIVE
  The purpose of this study was to assess whether body weight, body mass index, and scan length influence arterial enhancement during CT angiography (CTA) of the pulmonary arteries at different iodine flow rates.
  
  
  METHODS
  CTA examinations of the pulmonary arteries performed for routine clinical care of 120 patients between March and December 2003 were retrospectively evaluated. Patients had received either 120 mL of contrast medium with an iodine concentration of 300 mg I/mL (group A) or 90 mL of contrast medium with an iodine concentration of 400 mg I/mL (group B). The iodine dose was 36 g, and the injection rate was 4 mL/s in all examinations. The iodine flow rate was 1.2 g I/s in group A and 1.6 g I/s in group B. Arterial attenuation along the z-axis was measured per patient, and the influence of body weight, body mass index, and scan length on enhancement of the pulmonary arteries in the two groups was assessed.
  
  
  RESULTS
  In group A and in group B, body weight and body mass index correlated significantly with mean enhancement along the z-axis (r = -0.35 and -0.26 for group A and -0.48 and -0.40 for group B). Scan length showed no correlation with pulmonary attenuation. Mean pulmonary artery enhancement was significantly higher in group B with a difference of 51 H compared with group A.
  
  
  CONCLUSIONS
  Pulmonary artery attenuation in CTA of the pulmonary arteries shows a small but significant correlation with body weight and body mass index independently of the iodine flow rate used. A higher iodine flow rate improves pulmonary artery enhancement.
authors.affiliation: Department of Radiology, Medical University Graz, 8036 Graz, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Schoellnast
authors.forename: Hannes A
authors.initials: HA
authors.lastname: Deutschmann
authors.forename: Andrea
authors.initials: A
authors.lastname: Berghold
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Fritz
authors.forename: Gottfried J
authors.initials: GJ
authors.lastname: Schaffler
authors.forename: Manfred
authors.initials: M
authors.lastname: Tillich
mesh_terms: D000792:Angiography / Q000379:methods*; D015992:Body Mass Index; D001835:Body Weight; D003287:Contrast Media / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide