title: Quantification of ultrasound contrast agent response: comparison of continuous wave Doppler and power Doppler to backscattered radiofrequency data.
abstract: Our goal was to compare two quantification methods of ultrasound contrast agents available in clinical practice [continuous wave Doppler intensity (CWDI) and power Doppler intensity (PWDI)] to the reference technique (radio-frequency analysis) with a simple recirculating flow phantom using a renal dialysis cartridge. Measurements were made at different doses of perflenapent emulsion and BR1. Cineloops of power Doppler images were recorded using a clinically available ultrasound unit (HDI 3000). Simultaneously, integrated backscatter (IBS) was measured by analysis of radiofrequency signals, whereas Doppler signal intensity was measured with a continuous wave Doppler device. A linear relationship was found between CWDI and IBS and between PWDI and IBS when R(2) was calculated for each pair of parameters injection-by-injection. Results are summarized by the average R(2) for all injections between CWDI and IBS (BR1: R(2) = 0.93 +/- 0.05, perflenapent emulsion: R(2) = 0.94 +/- 0.03) and between PWDI and IBS (BR1: R(2) = 0.88 +/- 0.07, perflenapent emulsion: R(2) = 0.79 +/- 0.09). However, for all data obtained from all different injected doses and for both contrast agents, there was considerable variation of CWDI and PWDI values measured for a given value of IBS. In conclusion, for a fixed microbubble population, CWDI and PWDI can be proposed for quantification of USCA. However, their important variations observed at each dose make it difficult to link a single value of PWDI or CWDI or IBS to a single microbubble distribution composition.
authors.affiliation: Laboratoire d'Imagerie Parametrique, UMR 7623 CNRS, Paris University VI, 15 rue de l'Ecole de Medecine, 75006 Paris, France. olivier.lucidarme@lip.bhdc.jussieu.fr
authors.forename: O
authors.initials: O
authors.lastname: Lucidarme
authors.forename: J M
authors.initials: JM
authors.lastname: Correas
authors.forename: S L
authors.initials: SL
authors.lastname: Bridal
authors.forename: G
authors.initials: G
authors.lastname: Berger
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage / Q000737:chemistry*; D005466:Fluorocarbons / Q000008:administration & dosage / Q000737:chemistry*; D007267:Injections; D019047:Phantoms, Imaging; D010743:Phospholipids / Q000008:administration & dosage / Q000737:chemistry*; D012815:Signal Processing, Computer-Assisted; D013459:Sulfur Hexafluoride / Q000008:administration & dosage / Q000737:chemistry*; D018608:Ultrasonography, Doppler / Q000379:methods*; D010420:Pentanes
chemical_list: D003287:Contrast Media; D005466:Fluorocarbons; D010743:Phospholipids; D013459:Sulfur Hexafluoride; C420843:contrast agent BR1; C008806:perfluoropentane; D010420:Pentanes