The causes of pulsatile tinnitus are complex and often require appropriate investigations according to the possible causes. For example, when dural arteriovenous malformations are suspected, cranial MRI combined with high definition magnetic resonance angiography can be done; CT of the temporal bone can be done when jugular vein bullae are suspected; X-ray angiography can be used to find out if there are any vascular malformations or arteriovenous fistulas; ultrasonography can help diagnose carotid atherosclerosis. Other than this, audiological investigations are routine and include tonography, pure tone audiometry, hyperacoustic threshold, speech audiometry, acoustic conductance audiometry and electrical response audiometry. If necessary, laboratory tests such as erythrocyte sedimentation rate, blood rheology, blood glucose and lipids will also be performed.