Recently, Magnetic Resonance Imaging (MRI) of the lung has been shown to be a feasible alternative to CT for the detection of pulmonary metastases in adults with sensitivities and specificities of over 90% for the detection of nodules 5mm or larger. It has also shown promise in the characterization of nodules as benign or malignant. Since MRI does not involve radiation, it may prove to be a preferable imaging technique for children. We wish to evaluate the potential for MRI to complement or even replace CT in the imaging of pulmonary metastatic disease in children.