Pergamon l zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Original Contribution Magnetic Resonance Imaging, Vol. 12, No. 4, pp. 589-598, 1994 Copyright 0 1994 Elsevier Science Ltd Printed in the USA. All rights reserved 0730-72.5X/94 $6.00 + .OO 0730-725X(93)EOO63-T AUTOMATED MYOCARDIAL EDGE DETECTION FROM BREATH-HOLD CINE-MR IMAGES: EVALUATION OF LEFT VENTRICULAR VOLUMES AND MASS CLAIRE BALDY, PHILIPPE DOUEK, PIERRE CROISILLE, ISABELLE E. MAGNIN, DIDIER REVEL, AND MICHEL AMIEL URA CNRS 1216, Departement de Radiologie, Hopital Cardiovasculaire et Pneumologique, BP Lyon Montchat, 69394 Lyon Cedex 03, France This paper describes an automated edge detection method for the delineation of the endo- and epicardial borders of the left ventricle from magnetic resonance (MR) images. The feasibility of this technique was demonstrated by processing temporal series of cardiac MR images obtained in 12 healthy subjects and acquired from the apex to the base of the heart in multiple anatomic short axis planes with a breath-hold tine-MR acquisition sequence. This procedure allows the entire heart to be imaged in less than 5 min. The automatic program correctly identified the edges in most cases. In poor contrasted images, a fast and user-friendly interactive procedure was used to cor- rect the border delineation. The proposed method for the contour tracing requires a limited degree of control by the user and thus considerably reduces the tedious and long operator time inherent in the usual manual contour tracing tool. The left ventricular volumes were directly measured from these sets of contours by using the Simpson rule, allowing the end-diastolic volumes (EDV), the end-systolic volumes (ESV), the ejection fraction (EF) and the myocardial mass to be determined. The values measured in this study with the dedicated software were similar to the literature values (EDV = 78.3 ml/m2; ESV = 21.1 ml/m2; EF = 73 %). Associated with the ultrafast breath- hold tine-MR imaging, the described edge detection method provides an efficient clinical tool for the direct assess- ment of cardiac function. Keywords: Segmentation; Cardiac borders; Heart functions; Magnetic resonance imaging. INTRODUCTION Detailed information on cardiac dimensions and func- tion is of great interest for cardiac diagnosis and treat- ment monitoring, as well as for basic physiological and biomechanical studies of cardiac wall shear. During the last few years, several attempts have been made to use magnetic resonance imaging (MRI) as a noninvasive technique for the assessment of cardiac function. Spe- cifically, the determination of the left ventricular (LV) volumes, ejection fraction and mass can potentially provide important prognostic information in patients with congenital or acquired heart disease. When images are acquired through the entire length of the LV cav- ity, the direct and precise measurement of these vari- ables can be achieved by using the Simpson rule without any geometric assumption. Cine-MR imaging tech- niques offer sufficient temporal and spatial resolution for the noninvasive assessment of left ventricular func- tion. Their accuracy and reproducibility have been proved.‘** However, the complete examination of the heart in a three-dimensional approach by using stan- dard tine-MR imaging requires up to 40 min. This lengthy imaging time and its costs limit the widespread clinical usefulness of this method. Several attempts have been made to reduce the data acquisition time. Recently, an ultrafast gradient-echo sequence has been described, which makes use of a segmented k-space RECEIVED 6/8/93; zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ACCEPTED 10/19/93. Address correspondence to Claire Baldy, PhD, Departe- ment de Radiologie, Hopital Cardiovasculaire et Pneumo- logique, BP Lyon Montchat, 69394 Lyon Cedex 03, France. Supported in part by a convention with SIEMENS (CIFRE N” 269/90). 589