Time-resolved three-dimensional contrast-enhanced magnetic resonance angiography in patients who have undergone a Fontan operation or bidirectional cavopulmonary connection: initial experience.

PURPOSE

To evaluate the usefulness of time-resolved three-dimensional (3D) magnetic resonance angiography (MRA) using diluted contrast agent (CA) in patients who had undergone a Fontan operation or bidirectional cavopulmonary connection (BCPC).

MATERIALS AND METHODS

Time-resolved 3D MRA (10 dynamic data sets, two seconds per dynamic data set) using parallel imaging and keyhole data sampling was performed on 15 patients (median age=10 years, range=1-20 years) who had undergone a Fontan operation (N=11) or BCPC (N=4). Diluted gadolinium (Gd) contrast agent (CA) was intravenously injected into the arm and/or leg veins. The flow dynamics and morphology of pulmonary circulation, and lung perfusion were assessed.

RESULTS

Preferential or balanced pulmonary blood flow from each systemic vein was visualized on time-resolved 3D MRA in all patients. In addition, occlusion/stenosis of the central thoracic vein (N=4) and pulmonary artery (N=6), systemic venous (N=5) and arterial (N=6) collaterals, and lung perfusion defect (N=4) were identified. Persistent hepatic venous plexus, pulmonary arteriovenous malformation, and axillary arteriovenous fistula were delineated in three patients, respectively.

CONCLUSION

Time-resolved 3D MRA with diluted CA is useful for evaluating patients who have undergone a Fontan operation or BCPC because it can reveal the flow dynamics and morphology of pulmonary circulation, and lung perfusion status.