Venogram: Visualisation of a vein, usually by injecting contrast medication into it. Venogram can also be done without injecting contrast using magnetic resonance imaging (MRI). In MRI, movement of hydrogen ions in the blood generates the contrast.
Cerebral venogram is used to visualize the blood vessels of the brain. In a condition known as post partum cerebral venous thrombosis, in which a lady develops fits and alteration of consciousness after delivery, cerebral venogram is used for diagnosis.
Venogram of the blood vessels draining deoxygenated blood from the heart is taken prior to certain procedures like cardiac resynchronization therapy (implantation of a heart failure treatment device). This is done to find out a vein which is most suitable to place the pacemaker leads for synchronizing the contractions of the different walls of the left ventricle (lower muscular chamber of the heart).
Venogram of the upper limb is usually taken while implanting a pacemaker to find out the route which the veins travel from the upper limb to the chest. This helps the operator to find out the best site of skin puncture to get into the subclavian vein which is located behind the collar bone.
Veins of the lower limb can be visualised by venogram to know whether there are clots in them (deep vein thrombosis). But these are usually sought by Doppler ultrasound which is non-invasive and virtually free of any side effect.