Fig. 21

Knee recesses. The sagittal (a) fat saturated proton density weighted image shows fluid in the subpopliteal-subgastrocnemius (white arrow) and posterior femoral recess (black arrow). Findings of ACL reconstruction are also visible (in dotted line). The axial (b) fat saturated proton density weighted image shows a fluid distended posterior capsular recess which is located posteriorly to the PCL. The axial (c) fat saturated proton density weighted image shows fluid in the subpopliteal recess (white arrow). A Baker cyst (with asterisk) and geodes (black arrows) at both tibial condyles are also shown. The axial (d) fat saturated proton density weighted image shows the central recesses (white arrows) with fluid extending medially and laterally deep to the patellar retinacula