Magnetic resonance imaging of systemic venous anomalies.

Seven cases of anomalous development of the systemic great veins were found in the first 18 months of adult body imaging with a 0.15 T resistive magnetic resonance unit. Comparison was made with CT. In most cases, CT and MRI were equivalent in demonstrating the abnormality. In one case, MRI was superior to a drip-infusion CT. MRI was less successful when the low signal abnormal vein was adjacent to normal structures of low signal. Awareness of the MRI appearance of venous anomalies will aid their recognition as incidental findings.