title: Effects of injection rate and dose on image quality in time-resolved magnetic resonance angiography (MRA) by using 1.0M contrast agents.
abstract: In time-resolved MRA (TR MRA), injection parameters and contrast agent (CA) dose are important factors influencing image quality. In this study, three different injection schemes with different CA volumes were evaluated in 12 healthy volunteers. Injection rates between 0.2 and 0.8 ml/s were evaluated with CA volumes of 10 and 20 ml. To measure circulatory parameters, cine cardiac MRI was performed before each exam. Spatial resolution could be reduced to 2 x 1.4 x 2 mm3, temporal resolution was 2.25 s/frame. To exclude signal saturation at high CA concentrations, a phantom with fixed CA concentrations was placed in the field of view. SNR was measured, and the area under the curve of the arterial signal of the different injection schemes was calculated. Results showed the largest diagnostic window at a relatively slow injection rate of 0.4 ml/s and a CA volume of 10 ml. Circulatory parameters have an important impact on CA arrival, so delay times have to be set depending on these parameters.
authors.affiliation: Institute of Clinical Radiology, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany. harald.kramer@med.uni-muenchen.de
authors.forename: Harald
authors.initials: H
authors.lastname: Kramer
authors.forename: Henrik J
authors.initials: HJ
authors.lastname: Michaely
authors.forename: Martin
authors.initials: M
authors.lastname: Requardt
authors.forename: Martin
authors.initials: M
authors.lastname: Rohrer
authors.forename: Scott
authors.initials: S
authors.lastname: Reeder
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
mesh_terms: D000328:Adult; D019540:Area Under Curve; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D009942:Organometallic Compounds / Q000008:administration & dosage* / Q000493:pharmacokinetics; D019047:Phantoms, Imaging; D013997:Time Factors
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol