title: Assessment of regional myocardial strain by a novel automated tracking system from digital image files.
abstract: Myocardial strain imaging by Doppler tissue echocardiography is a useful method to quantify regional left ventricular function. However, this method has a problem of its Doppler angle dependency. We attempted to quantify myocardial strain by a newly developed automated tracking system from digital image files. In 6 anesthetized open-chest dogs, a pair of ultrasonic crystals was implanted at the inner site and outer site of the left ventricular wall to measure myocardial radial strain. B-mode echocardiographic images and trajectories of crystals were recorded simultaneously. Three conditions were examined by intravenous infusion of dobutamine. We used a pattern matching algorithm, which allowed us to track objects from one frame to the next. In 18 image sequences obtained in the 6 dogs, there was an excellent correlation in maximal myocardial strain between the two methods ( r = 0.92, P < .0001). Thus, this system is a promising tool to provide automated quantification of regional myocardial strain.
authors.affiliation: Department of Cardiology, Kawasaki Medical School, Kurashiki City, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Toyoda
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Baba
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
authors.forename: Maki
authors.initials: M
authors.lastname: Akiyama
authors.forename: Yoji
authors.initials: Y
authors.lastname: Neishi
authors.forename: Junko
authors.initials: J
authors.lastname: Tomita
authors.forename: Renan
authors.initials: R
authors.lastname: Sukmawan
authors.forename: Yuji
authors.initials: Y
authors.lastname: Koyama
authors.forename: Nozomi
authors.initials: N
authors.lastname: Watanabe
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tamano
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Shinomura
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000465:Algorithms; D000818:Animals; D004285:Dogs; D015150:Echocardiography, Doppler / Q000295:instrumentation / Q000379:methods*; D025401:Echocardiography, Stress / Q000295:instrumentation / Q000379:methods*; D005260:Female; D007091:Image Processing, Computer-Assisted; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium; D016277:Ventricular Function, Left / Q000502:physiology*