InternationalJournalof CardiacImaging 7: 73-78, 1991. © 1991 Kluwer AcademicPublishers. Printedin the Netherlands. Quantitative regional curvature analysis: validation in animals of a method for assessing regional ventricular remodelling in ischemic heart disease G.B. John Mancini & Mark J. McGillem Department of Internal Medicine, University of Michigan Medical School, Veterans Administration and University of Michigan Medical Centers, Ann Arbor, Michigan, USA Accepted30 July 1991 Key words: shape analysis, regional function, wall motion, wall thickening, ventricular function, ischemia, coronary disease, remodelling Abstract Recent studies show the impact of left ventricular shape and remodelling on patient prognosis. This mandates the development of quantitative methods for measuring shape. Quantitative regional curvature analysis (QRCA) was developed to quantitate shape on a regional basis so that measurements would not be constrained to assessment of only global shape and would, therefore be applicable to ischemic heart disease. To validate QRCA, eleven dogs were instrumented with coronary occluders and radiopaque markers on the epicardium and endocardium to provide fiducial points for calculation of shape, motion and thickening. These parameters were measured in the anterior and inferior walls, at rest, during left anterior descending occlusion and finally during circumflex occlusion. QRCA showed increased curvature (increased globular- it),) in each wall when thickening and motion deteriorated during occlusion. The most marked shape changes occurred in the inferior wall whereas the most marked deterioration of function was detected by wall thickening measurements of the anterior wall. Thus, QRCA detects regional ventricular shape disorders coincident with regional dysfunction induced by ischemia. These changes show regional heterogeneity and demonstrate the potential importance of this measurement as opposed to simple, global measures of shape. QRCA is, therefore, suitable for monitoring acute changes of shape that occur during acute ischemia. Introduction Shape and remodelling are increasingly being rec- ognized as important parameters in the assessment of ventricular function [1]. Quantitative Regional Curvature Analysis (QRCA) was specifically de- veloped to provide quantitative measures of these important attributes and processes that character- ize the ventricular response to injury [2-7]. More- over, it was developed to allow measurements of ventricular shape on a regional basis that are inde- pendent of ventrictdar size, or volume. QRCA has been applied to clinical studies of contrast ventricu- lography which have shown that parameters of shape correlate with measures of regional wall mo- tion [4-5]. However, due to uncertainties in the location of the endocardial wall in contrast ventri- culographic studies, these applications cannot be considered suitable for validating the method or determining whether shape changes parallel acute deterioration of regional function. Therefore, the purpose of the study was to validate QRCA in animals with implanted, lead markers that provide a fiducial reference for ventricular wall motion and wall thickening measurements and to determine if conformational changes measured by QRCA par-