Sagittal MRI of the right knee. The posterior compartment of the knee is visualized; however, the popliteus is not seen in the popliteal hiatus (green arrow). It would normally be seen at the posterior horn of the lateral meniscus. There is edema around the soleus muscle posterior to the popliteal hiatus, deep to the lateral head of the gastrocnemius (blue arrow).Abbreviations: S, Superior; I, Inferior; A, Anterior; P, Posterior.