American Journal of Roentgenology, Vol 172, 1061-1065, Copyright © 1999 by American Roentgen Ray Society

ARTICLES

Relationship between motion of coronary arteries and diaphragm during free breathing: lessons from real-time MR imaging

PG Danias, M Stuber, RM Botnar, KV Kissinger, RR Edelman and WJ Manning
Department of Medicine, Charles A. Dana Research Institute and the Harvard-Thorndike Laboratory, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.

OBJECTIVE: Diaphragmatic navigators are frequently used in free- breathing coronary MR angiography, either to gate or prospectively correct slice position or both. For such approaches, a constant relationship between coronary and diaphragmatic displacement throughout the respiratory cycle is assumed. The purpose of this study was to evaluate the relationship between diaphragmatic and coronary artery motion during free breathing. SUBJECTS AND METHODS: A real-time echoplanar MR imaging sequence was used in 12 healthy volunteers to obtain 30 successive images each (one per cardiac cycle) that included the left main coronary artery and the domes of both hemidiaphragms. The coronary artery and diaphragm positions (relative to isocenter) were determined and analyzed for effective diaphragmatic gating windows of 3, 5, and 7 mm (diaphragmatic excursions of 0-3, 0-5, and 0-7 mm from the end-expiratory position, respectively). RESULTS: Although the mean slope correlating the displacement of the right diaphragm and the left main coronary artery was approximately 0.6 for all diaphragmatic gating windows, we also found great variability among individual volunteers. Linear regression slopes varied from 0.17 to 0.93, and r2 values varied from .04 to .87. CONCLUSION: Wide individual variability exists in the relationship between coronary and diaphragmatic respiratory motion during free breathing. Accordingly, coronary MR angiographic approaches that use diaphragmatic navigator position for prospective slice correction may benefit from patient-specific correction factors. Alternatively, coronary MR angiography may benefit from a more direct assessment of the respiratory displacement of the heart and coronary arteries, using left ventricular navigators.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				S. Plein, S. Bulugahapitiya, T. R. Jones, G. J. Bainbridge, J. P. Ridgway, and M. U. Sivananthan Cardiac MR Imaging with External Respirator: Synchronizing Cardiac and Respiratory Motion—Feasibility Study Radiology, June 1, 2003; 227(3): 877 - 882. [Abstract] [Full Text] [PDF]

				B. Giorgi, S. Dymarkowski, F. Maes, M. Kouwenhoven, and J. Bogaert Improved Visualization of Coronary Arteries Using a New Three-Dimensional Submillimeter MR Coronary Angiography Sequence with Balanced Gradients Am. J. Roentgenol., October 1, 2002; 179(4): 901 - 910. [Abstract] [Full Text] [PDF]

				K. Nehrke, P. Bornert, D. Manke, and J. C. Bock Free-breathing Cardiac MR Imaging: Study of Implications of Respiratory Motion—Initial Results Radiology, September 1, 2001; 220(3): 810 - 815. [Abstract] [Full Text] [PDF]

				M. J. Lipton, L. M. Boxt, and Z. M. Hijazi Role of the Radiologist in Cardiac Diagnostic Imaging Am. J. Roentgenol., December 1, 2000; 175(6): 1495 - 1506. [Full Text] [PDF]