X-rays provide information about bone deformities. The lower picture illustrates a pincer deformity. The red dots show the border of the anterior acetabular wall the green arrow points to an area of reactive sclerosis that occured as a result of the impingement on the femoral neck.
MRI arthrogram
The MRI arthrogram can help us to diagnose labral tears and anterior CAM deformities. The upper picture shows an axial cut through the hip joint. The femoral head has lost its spherical shape. We can quantify the abnormality of the femoral head by measuring the alpha angle. This can help us in predicting the presence of articular cartilage lesions.
In this example the alpha angle measures 68 degress and it is likely that this patient has an articular cartilage lesion.
Northern Hip & Groin Institute