title: Discrimination of early/intermediate and advanced/complicated coronary plaque types by radiofrequency intravascular ultrasound analysis.
abstract: Radiofrequency intravascular ultrasound (IVUS-RF) analysis, as an extension of conventional IVUS imaging, may provide more accurate plaque discrimination. Thirty-two autopsy atherosclerotic coronary arteries were investigated. Corresponding sectors in different plaques were matched by histologic and RF analysis. Histologic analysis utilized the American Heart Association plaque classification. The backscattered ultrasound RF signal was analyzed by fast-Fourier transform, providing the underlying frequency components of its power spectrum. The normalized backscattered signal power (in decibels [dB]) for frequencies between 15.3 and 40.3 MHz was then measured for plaque discrimination. Advanced/complicated plaque types showed a higher signal power at all frequencies than early/intermediate lesion types (p <0.001 to p = 0.005). Discrimination of advanced/complicated lesion types was best at 15.3 MHz, with a cut-off point of 2.5 dB (sensitivity 93%, specificity 79%), and second best at 17.6 MHz (sensitivity 87%, specificity 71%, cut-off point 1.9 dB). With conventional IVUS, plaque discrimination was weaker; the best sensitivity for diagnosing early/intermediate lesion types was reached for "soft plaque" (sensitivity 63%, specificity 73%). Compared with conventional IVUS, IVUS-RF can discriminate between advanced/complicated and early/intermediate coronary atherosclerotic lesions with relatively high sensitivity and specificity in vitro.
authors.affiliation: Stanford University Medical School, Stanford, California 94305, USA.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Stähr
authors.forename: Tobias
authors.initials: T
authors.lastname: Höfflinghaus
authors.forename: Thomas
authors.initials: T
authors.lastname: Voigtländer
authors.forename: Brian K
authors.initials: BK
authors.lastname: Courtney
authors.forename: Anja
authors.initials: A
authors.lastname: Victor
authors.forename: Mike
authors.initials: M
authors.lastname: Otto
authors.forename: Paul G
authors.initials: PG
authors.lastname: Yock
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Brennecke
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
mesh_terms: D002102:Cadaver; D003324:Coronary Artery Disease / Q000145:classification / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional / Q000379:methods*