3 yo female, 16.8 kg, 91.4 cm, 0.65 m^2; Complex perimembranous to muscular VSD with band dividing it into a large anterior component and smaller posterior component. There is a parallel RV muscle bundle that does not divide the RV inflow and outflow chambers and is at risk to be mistaken for the septum. A swiss cheese apical VSD is suspected. Educational Learning: Pulmonary artery band in good position. Qp:Qs of 0.82:1 consistent with balanced circulation. When true septal plane is utilized, normal LV size with borderline RV size at 39.7 ml/m^2, however, when parallel RV muscle bundle is utilized as septal plane, the RV size becomes hypoplastic at 28.9 ml/m^2.  A GE 1.5T HDxt system was used for the 3D HEART sequence which used a 3D respiratory-navigated balanced SSFP (steady state free precession) multi-slab sequence with T2 preparation that provides whole heart coverage with high contrast-to-noise ratio between vessels and myocardium. Heart rate 90 bpm, Images obtained in diastole:  The sequence was run with the following parameters: TR 3.98, TE 1.67, TD 486ms