Original ArticleRingTag Ring-Shaped Tagging for Myocardial Centerline AssessmentSpiegel, Marcus A. PhD*; Luechinger, Roger PhD*; Schwitter, Jueg MD†; Boesiger, Peter PhD*Author Information From the *Institute for Biomedical Engineering, University and ETH; and the †Division of Cardiology, University Hospital, Zurich, Switzerland. Received January 26, 2003; and accepted for publication June 12, 2003. Correspondence to: Prof. Dr. P. Boesiger, Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, 8092 Zurich, Switzerland. E-mail: [email protected] Investigative Radiology: October 2003 - Volume 38 - Issue 10 - p 669-678 doi: 10.1097/01.rli.0000084888.79706.3a Buy Metrics Abstract Rationale and objectives: Although endocardial ejection indexes lead to overestimation of contractility in hypertrophied hearts, circumferential fiber shortening at the mid wall (cFS) is less affected by wall thickness. In this study magnetic resonance tagging is exploited to assess directly cFS in normal and hypertrophied hearts. Methods: A novel tagging procedure generates freely definable, convex ring saturation bands. Data acquisition during the cardiac cycle is achieved with a fast, single breath-hold echo-planar imaging measurement that is combined with a slice-following approach and a navigator-guided breath-holding technique to improve reproducibility of breath hold positions. Results: The procedure is able to create variably shaped convex saturation structures on the myocardium that can be tracked automatically throughout the cardiac cycle. Circumferential shortening at the endocardial border (FSendo) obtained in 6 healthy volunteers and in 6 patients with hypertensive cardiomyopathy suggested hypercontractility of hypertrophied hearts (30.7 ± 4.1% vs. 43.9 ± 4.4% respectively; P < 0.002), whereas shortening at the level of the myofibers assessed as cFS was not different (17.2 ± 1.4% vs. 18.1 ± 2.8% respectively; P = 0.49). Conclusions: The presented approach allows for assessment of midwall myocardial mechanics and may become a useful tool to study contractile function in hypertrophied hearts. © 2003 Lippincott Williams & Wilkins, Inc.