4-dimensional, multiphase, steady-state imaging with contrast enhancement (MUSIC) in the heart; a feasibility study in children

PURPOSE To develop a technique for high resolution, four-dimensional (4D), multiphase, steady-state imaging with contrast enhancement (MUSIC) in children with complex congenital heart disease. METHODS Eight pediatric patients underwent cardiovascular MRI with controlled mechanical ventilation after ferumoxytol administration. Breath-held contrast-enhanced MRA (CE-MRA) was performed during the first-pass and delayed phases of ferumoxytol, followed by a respiratory gated, 4D MUSIC acquisition during the steady state distribution phase of ferumoxytol. The subjective image quality and image sharpness were evaluated. Assessment of ventricular volumes based on 4D MUSIC was compared with those based on multislice 2D cardiac cine MRI. RESULTS The 4D MUSIC technique provided cardiac-phase-resolved (65-95 ms temporal resolution) and higher spatial resolution (0.6-0.9 mm isotropic) images than previously achievable using first-pass CE-MRA or 2D cardiac cine. When compared with Ferumoxytol-based first-pass CE-MRA, the 4D MUSIC provided sharper images and better definition of the coronary arteries, aortic root, myocardium, and pulmonary trunk (P < 0.05 for all). The ventricular volume measurements were in good agreement between 4D MUSIC and 2D cine (concordance correlation coefficient >0.95). CONCLUSION The 4D MUSIC technique may represent a new paradigm in MR evaluation of cardiovascular anatomy and function in children with complex congenital heart disease.