To understand the anatomy of the greater sciatic foramen, which is important for the radiologist to make appropriate diagnosis and spread of the disease through the foramen. To be familiar with the interventional procedures through the greater sciatic foramen will allow the radiologist to provide the appropriate management.

CT and MRI anatomy of the greater sciatic foramen with focusing on structures passing through the foramen. Cases of sciatic hernia, malignant lymphoma, lymphnode metastasis, neurogenic tumor, lipoma, abscess, hematoma etc are shown. Extrapelvic spread of diseases (hematoma, abscess, tumor) through the greater sciatic foramen are demonstrated with discussion. Interventional procedures, such as needle biopsy, percutaneous abscess drainage, direct puncture approach to the superior rectal vein through the greater sciatic foramen to treat rectal varices are shown with discussion.