The axial PD-weighted images are important for examination of the patellofemoral compartment articular cartilage, the collateral ligaments, and cruciate ligaments. As with the proton density images in the sagittal plane, it is important to pay attention to the inter-echo spacing and echo train length to avoid blurring due to T2 decay of the high spatial frequencies of k-space. It is important to specify that the frequency direction be A/P so that pulsation artifact from the popliteal artery does not obscure the patellofemoral joint articular cartilage.