radioiodine labelled fibrinogen uptake

Last reviewed 01/2018

The uptake of radioiodine (I,125) labelled fibrinogen may be used to detect thrombus throughout the calf and in the lower three quarters of the thigh.

It is a highly sensitive technique. Only 50% of DVT's detected on labelled fibrinogen scanning are identified clinically and studies using this technique reveal post operative DVT in up to 30% of patients over 40 years old.

Despite these results, however, the technique is falling out of favour, as:

• it cannot detect thrombus which has formed before the labelled fibrinogen is given
• it is unreliable in the pelvic and hip region, since the bladder is in close proximity and may contain excreted radioiodine
• it is of little use following knee or hip surgery since labelled fibrinogen accumulates at the site of the operation
• it is contraindicated during pregnancy
• lower limb incisions may give false positive results
• there is a risk of hepatitis