What is the angle for the central ray when performing an anteroposterior (AP) mortise ankle radiograph?

The angle for the central ray during an anteroposterior (AP) mortise ankle radiograph should indeed be set at 0 degrees. This positioning ensures that the central ray is perpendicular to the film or receptor, allowing for a clear and accurate view of the ankle joint anatomy, particularly the mortise joint, which includes the tibia, fibula, and talus. By maintaining a 0-degree angle, you help prevent distortion and overlapping of bony structures in the image, leading to better diagnostic quality.

In AP mortise views, the necessity to visualize the joint space effectively means that an exact perpendicular approach is vital for achieving the optimal representation of the ankle's alignment and integrity. Any angling of the central ray other than 0 degrees could result in compromised image quality and an inaccurate assessment of the ankle joint.