title: Automated grading of left ventricular segmental wall motion by an artificial neural network using color kinesis images.
abstract: The present study describes an auxiliary tool in the diagnosis of left ventricular (LV) segmental wall motion (WM) abnormalities based on color-coded echocardiographic WM images. An artificial neural network (ANN) was developed and validated for grading LV segmental WM using data from color kinesis (CK) images, a technique developed to display the timing and magnitude of global and regional WM in real time. We evaluated 21 normal subjects and 20 patients with LVWM abnormalities revealed by two-dimensional echocardiography. CK images were obtained in two sets of viewing planes. A method was developed to analyze CK images, providing quantitation of fractional area change in each of the 16 LV segments. Two experienced observers analyzed LVWM from two-dimensional images and scored them as: 1) normal, 2) mild hypokinesia, 3) moderate hypokinesia, 4) severe hypokinesia, 5) akinesia, and 6) dyskinesia. Based on expert analysis of 10 normal subjects and 10 patients, we trained a multilayer perceptron ANN using a back-propagation algorithm to provide automated grading of LVWM, and this ANN was then tested in the remaining subjects. Excellent concordance between expert and ANN analysis was shown by ROC curve analysis, with measured area under the curve of 0.975. An excellent correlation was also obtained for global LV segmental WM index by expert and ANN analysis (R2 = 0.99). In conclusion, ANN showed high accuracy for automated semi-quantitative grading of WM based on CK images. This technique can be an important aid, improving diagnostic accuracy and reducing inter-observer variability in scoring segmental LVWM.
authors.affiliation: Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: L O
authors.initials: LO
authors.lastname: Murta
authors.forename: E E S
authors.initials: EE
authors.lastname: Ruiz
authors.forename: A
authors.initials: A
authors.lastname: Pazin-Filho
authors.forename: A
authors.initials: A
authors.lastname: Schmidt
authors.forename: O C
authors.initials: OC
authors.lastname: Almeida-Filho
authors.forename: M V
authors.initials: MV
authors.lastname: Simões
authors.forename: J A
authors.initials: JA
authors.lastname: Marin-Neto
authors.forename: B C
authors.initials: BC
authors.lastname: Maciel
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D016571:Neural Networks, Computer; D012372:ROC Curve; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*