The "broken ring" sign in magnetic resonance imaging of partial anomalous pulmonary venous connection to the superior vena cava.

In two patients with partial anomalous pulmonary venous connection to the superior vena cava, we attempted to demonstrate the pertinent anatomic abnormalities by using magnetic resonance imaging. The results show that magnetic resonance imaging is an ideal cardiovascular imaging modality. The observation of a "broken ring" structure in the magnetic resonance image of the superior vena cava is proposed as a diagnostic sign of partial anomalous pulmonary venous connection to the superior vena cava.