title: Dual-bolus approach to quantitative measurement of pulmonary perfusion by contrast-enhanced MRI.
abstract: OBJECTIVE
  To evaluate a dual-bolus approach to pulmonary perfusion MRI.
  
  
  METHODS
  The dual-bolus approach uses a separate low-dose measurement for the arterial input function (AIF) to ensure linearity. The measured AIF is constructed according to a subsequent higher dose used for the tissue concentration curves in the lung. In this study a prebolus of 0.01 mmol/kg followed by doses of 0.04 mmol/kg and 0.08 mmol/kg was used. Measurements were performed using time-resolved two-dimensional fast low-angle shot (2D FLASH) MRI (TE/TR = 0.73 msec/1.73 msec; flip angle = 40 degrees ; generalized autocalibrating partially parallel acquisitions (GRAPPA) factor = 3; temporal resolution = 400 msec) in end-inspiratory breath-hold.
  
  
  RESULTS
  The combination of prebolus/0.04 mmol/kg resulted in a pulmonary blood flow (PBF) of 211 +/- 77 mL/min/100 mL, and a pulmonary blood volume (PBV) of 20 +/- 3 mL/100 mL. The combination of prebolus/0.08 mmol/kg resulted in approximately 50% lower perfusion values, most likely due to saturation effects in the lung tissue.
  
  
  CONCLUSIONS
  A dual-bolus approach to pulmonary perfusion MRI is feasible and may reduce the problem of lacking linear relationship between the contrast-agent concentration and signal intensity.
authors.affiliation: Department of Medical Physics in Radiology, Deutsches Krebsforschungszentrum, Heidelberg, Germany. f.risse@dkfz-heidelberg.de
authors.forename: Frank
authors.initials: F
authors.lastname: Risse
authors.forename: Wolfhard
authors.initials: W
authors.lastname: Semmler
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
mesh_terms: D000328:Adult; D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media / Q000008:administration & dosage; D005240:Feasibility Studies; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods; D008168:Lung / Q000098:blood supply* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010865:Pilot Projects; D011652:Pulmonary Circulation / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA