title: Radio frequency dual-spectra analysis of regional myocardial perfusion: Comparison with harmonic densitometric method.
abstract: Our objective was to compare harmonic-to-fundamental frequency ratio peak (HFRp) analysis with conventional harmonic gray-scale densitometric analysis on the basis of ability to eliminate heterogeneity in ultrasound signals. Broadband radio frequency and harmonic data were obtained by using intermittent short-axis scans in 10 open-chest pigs before and during infusion of contrast microbubbles. HFRp and gray-scale intensity values were measured in 6 segments of left ventricular myocardium. In baseline images, the influence of anisotropy on HFRp values was significantly less than that in gray-scale intensities. In perfusion assessment with subtraction, contrast heterogeneity in HFRp values was significantly smaller than that in gray-scale intensities. The increase in HFRp values after subtraction was significantly greater than that in gray-scale intensities in lateral (P <.001), posterior (P <.0001), and inferior (P <.01) myocardium. HFRp analysis can compensate for baseline myocardial anisotropy and regional contrast heterogeneity. With background subtraction, HFRp analysis allows better quantification of myocardial perfusion.
authors.affiliation: Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Asanuma
authors.forename: Bijoy K
authors.initials: BK
authors.lastname: Khandheria
authors.forename: James B
authors.initials: JB
authors.lastname: Seward
authors.forename: Marek
authors.initials: M
authors.lastname: Belohlavek
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003720:Densitometry / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D007262:Infusions, Intravenous; D023421:Models, Animal; D008955:Models, Cardiovascular; D009206:Myocardium / Q000473:pathology; D010477:Perfusion; D011856:Radiographic Image Enhancement; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D013057:Spectrum Analysis; D013552:Swine
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals