Figure 1. Contrast-enhanced coronal images of the chest in the arterial phase show a hypodense filling defect in the superior vena cava (SVC) surrounded by a thin rim of contrast (straight arrow). A tubular hyperdensity (curved arrow) is seen within the filling defect, consistent with known right port-A catheter. Multiple serpiginous hyperdensities are seen in the thoraco-abdominal wall due to collateral flow (filled arrows). Findings indicate a partially occlusive SVC thrombus surrounding a port catheter with collateral flow.