Finger Brachial Index (FBI)
 

Similar to the ankle-brachial index (ABI), the FBI compares the blood pressure measurements taken from the fingers with those taken at the brachial artery in the arm. The FBI is calculated by dividing the systolic pressure in the finger by the systolic pressure in the arm. It provides a ratio that indicates the relative blood flow and pressure in the fingers compared to the arm.

A FBI is primarily used to diagnose and assess the severity of PAD affecting the fingers. A lower FBI value indicates reduced blood flow and potential blockages in the small arteries of the fingers, similar to what the ankle-brachial index (ABI) indicates for the lower extremities. The test helps healthcare providers evaluate the adequacy of blood supply to the fingers, assess the severity of PAD in the digits, and determine the risk of complications such as non-healing wounds, infections, or tissue damage in the fingers.

This test usually takes between 15-20 minutes to complete.

 

A Finger Brachial Index Pressure Study (FBI) assesses the ratio between the blood pressure in your arm compared to the arteries in each finger. A PPG, sphygmomanometer, blood pressure cuff and hand held doppler with a pencil probe will be used for this study. We will require you to remove your jumper. We will ask you to sit down on the examination bed. We will place a blood pressure cuff and PPG around each of your fingers while inflating and deflating the cuff to determine the blood pressure. We will use the hand-held Doppler to find the arteries and then inflate/deflate the blood pressure cuff to determine the blood pressure in your arm.

A finger brachial index (FBI) is a non-invasive test used to evaluate blood circulation and assess the degree of peripheral artery disease (PAD) in the fingers. It is similar to the ankle-brachial index (ABI) but focuses on the smaller blood vessels in the fingers. This test may be performed to:

 

Diagnosing peripheral artery disease (PAD)

A FBI can help diagnose the presence of PAD in the fingers.

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Evaluating the severity of peripheral artery disease

The test can provide information about the extent or severity of peripheral artery disease in the fingers. Lower FBI values indicate more significant arterial blockages and impaired blood flow.

 

Assessing wound healing and complications

Individuals with significant PAD in the fingers are at risk of poor wound healing, infections, or tissue damage in these areas. The finger brachial index test helps assess the adequacy of blood supply to the fingers and predicts the likelihood of complications.

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Monitoring disease progression and treatment effectiveness

FBI measurements can track the progression of peripheral artery disease in the fingers over time. They also help evaluate the effectiveness of interventions or treatments aimed at improving blood flow to the fingers.