ROLE OF SPIN-ECHO AND CINE MAGNETIC-RESONANCE-IMAGING IN PRESURGICAL PLANNING OF HETEROTAXY SYNDROME - COMPARISON WITH ECHOCARDIOGRAPHY ANDCATHETERIZATION

Background Patients with heterotaxy syndrome frequently have complex c ongenital cardiac and noncardiac malformations requiring detailed diag nostic evaluation by noninvasive as well as invasive imaging modalitie s for management planning. Recent advances in magnetic resonance imagi ng (MRI) techniques allow detailed delineation of cardiovascular anato my and blood flow in young infants with rapid heart rates. The present study was undertaken to prospectively evaluate the role of MRI in the presurgical evaluation of patients with heterotaxy syndrome. Methods and Results Between January 1 and December 31, 1992, 14 consecutive pa tients with heterotaxy syndrome and complex congenital heart disease w ere enrolled in a prospective protocol. After evaluation by echocardio graphy and cardiac catheterization, a tentative management plan was re corded. Subsequently, a MRI study was performed and surgical planning was reevaluated. MRI was found to be comparable to echocardiography in terms of length of examination and sedation requirements. Surgical pl anning was altered in four patients because MRI provided additional da ta not evident on echocardiography and catheterization. Comparison of diagnostic yield between echocardiography, catheterization, and MRI sh owed that MRI is superior to echocardiography and often to catheteriza tion in delineation of systemic and pulmonary venous anatomy and their relation to mediastinal structures. When the anatomic and hemodynamic data obtained by echocardiography and MRI were considered together, c ardiac catheterization data were necessary only to determination of pu lmonary vascular resistance before Fontan operation. Conclusions MRI p rovides excellent anatomic and functional information that in some pat ients was not available by echocardiography or catheterization. Combin ed with echocardiography, MRI provides the high-quality diagnostic inf ormation necessary for management planning in most patients with heter otaxy syndrome. Cardiac catheterization is indicated when determinatio n of pulmonary vascular resistance is necessary for decision making or when an interventional procedure is indicated.