HOME SUBSCRIPTIONS CURRENT ISSUE PAST ISSUES CARDIOSOURCE SEARCH HELP FEEDBACK		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Murashige, A. Articles by Matsuzaki, M. Search for Related Content PubMed PubMed Citation Articles by Murashige, A. Articles by Matsuzaki, M. Related Collections Related Article

CLINICAL RESEARCH: INTRAVASCULAR IMAGING AND VULNERABLE PLAQUE

Detection of Lipid-Laden Atherosclerotic Plaque by Wavelet Analysis of Radiofrequency Intravascular Ultrasound Signals

In Vitro Validation and Preliminary In Vivo Application

Division of Cardiovascular Medicine, Department of Medical Bioregulation, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan

Manuscript received June 13, 2004; revised manuscript received October 19, 2004, accepted October 25, 2004.

^_* Reprint requests and correspondence: Dr. Takafumi Hiro, Division of Cardiovascular Medicine, The Department of Medical Bioregulation, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami Kogushi, Ube, Yamaguchi 755-8505, Japan (Email: thiro{at}yamaguchi-u.ac.jp).

This study was presented in part at the 75th scientific sessions of the American Heart Association, Chicago, Illinois, 2002. Drs. Murashige and Hiro contributed equally to this work.

OBJECTIVES: This study examined the feasibility of using a wavelet analysis of radiofrequency (RF) intravascular ultrasound (IVUS) signals in detecting lipid-laden plaque.

BACKGROUND: Wavelet analysis is a new mathematical model for assessing local changes in a geometrical profile of time-series signals.

METHODS: Radiofrequency IVUS signals of 85 arbitrarily selected vectors were acquired from 27 formalin-fixed noncalcified atherosclerotic plaques from human necropsy with a digitizer at 500 MHz with 8-bit resolution by use of a 40-MHz IVUS catheter. Wavelet analysis of these RF signals was performed using a Daubechies-2 wavelet to obtain a color-coded map of the correlation coefficient with the wavelet reconstructed over the x-y plane of the wavelet scale and the distance from the IVUS catheter. The plaque segment was then examined histologically after being stained with Masson’s trichrome stain. This technique also was applied in vivo in 29 human coronary plaque segments. These segments were excised subsequently by directional coronary atherectomy and processed for histologic analysis.

RESULTS: In the in vitro study, histologic examination revealed lipid-laden segments in 29 vectors. When performing a wavelet analysis with the Daubechies-2 wavelet, the color-coded mapping revealed a different pattern in lipid-laden plaques compared with other types of plaque. Using this wavelet analysis, lipid-laden plaque could be detected with a sensitivity of 83% (24 of 29) and a specificity of 82% (46 of 56). In the in vivo study, fatty plaque could be detected with a sensitivity of 81% (13 of 16) and a specificity of 85% (11 of 13) with this method.

CONCLUSIONS: Wavelet analysis of RF IVUS signals enabled in vitro as well as in vivo detection of lipid-laden plaque. This method may be useful in assessing plaque vulnerability in patients with coronary artery disease.

Abbreviations and Acronyms   IVUS = intravascular ultrasound   RF = radiofrequency

Related Article

Picking Plaques That Pop ...

Jagat Narula, Aloke V. Finn, and Anthony N. DeMaria
J. Am. Coll. Cardiol. 2005 45: 1970-1973. [Full Text] [PDF]

This article has been cited by other articles:

				Y. Honda and P. J. Fitzgerald Frontiers in Intravascular Imaging Technologies Circulation, April 15, 2008; 117(15): 2024 - 2037. [Full Text] [PDF]

				P. K. Cheruvu, A. V. Finn, C. Gardner, J. Caplan, J. Goldstein, G. W. Stone, R. Virmani, and J. E. Muller Frequency and Distribution of Thin-Cap Fibroatheroma and Ruptured Plaques in Human Coronary Arteries: A Pathologic Study J. Am. Coll. Cardiol., September 4, 2007; 50(10): 940 - 949. [Abstract] [Full Text] [PDF]

				S. K. Mehta, J. R. McCrary, A. D. Frutkin, W. J.S. Dolla, and S. P. Marso Intravascular ultrasound radiofrequency analysis of coronary atherosclerosis: an emerging technology for the assessment of vulnerable plaque Eur. Heart J., June 1, 2007; 28(11): 1283 - 1288. [Abstract] [Full Text] [PDF]

				S. Waxman, F. Ishibashi, and J. E. Muller Detection and Treatment of Vulnerable Plaques and Vulnerable Patients: Novel Approaches to Prevention of Coronary Events Circulation, November 28, 2006; 114(22): 2390 - 2411. [Full Text] [PDF]

				M. Kawasaki, B. E. Bouma, J. Bressner, S. L. Houser, S. K. Nadkarni, B. D. MacNeill, I.-K. Jang, H. Fujiwara, and G. J. Tearney Diagnostic Accuracy of Optical Coherence Tomography and Integrated Backscatter Intravascular Ultrasound Images for Tissue Characterization of Human Coronary Plaques J. Am. Coll. Cardiol., July 4, 2006; 48(1): 81 - 88. [Abstract] [Full Text] [PDF]

				A. N. DeMaria, J. Narula, E. Mahmud, and S. Tsimikas Imaging vulnerable plaque by ultrasound. J. Am. Coll. Cardiol., April 18, 2006; 47(8 Suppl): C32 - C39. [Abstract] [Full Text] [PDF]

				K. Sano, M. Kawasaki, Y. Ishihara, M. Okubo, K. Tsuchiya, K. Nishigaki, X. Zhou, S. Minatoguchi, H. Fujita, and H. Fujiwara Assessment of Vulnerable Plaques Causing Acute Coronary Syndrome Using Integrated Backscatter Intravascular Ultrasound J. Am. Coll. Cardiol., February 21, 2006; 47(4): 734 - 741. [Abstract] [Full Text] [PDF]

				J. Narula, A. V. Finn, and A. N. DeMaria Picking Plaques That Pop ... J. Am. Coll. Cardiol., June 21, 2005; 45(12): 1970 - 1973. [Full Text] [PDF]