Background/Purpose:

Even though Doppler ultrasound(US) is used for
diagnosing inflammatory changes it is well-known that Doppler signals are seen
in healthy wrist and finger joints. Tenosynovitis has been shown to be frequent
in rheumatoid arthritis and to predict erosive disease. Detailed knowledge of
the distribution of feeding vessels in fingers is important to distinguish
normal from pathological findings. However, there is no knowledge about Doppler
signals in relation to healthy tendon sheaths and the possible pitfalls this
may generate.

To investigate presence of feeding vessels in relation
to the healthy flexor tendon sheaths of the fingers by use of 3D Doppler US.

Methods:

Twenty healthy participants were recruited, 10 women
in the age 23-67 years and 10 men in the age 26-54 years. None of the
participants had finger pain, history of arthritis or any known finger tendon
disease. One participant was a smoker.

The participants had US of the right second
and third flexor tendon of the finger (10 men, 10 women). US was carried out using
a General
Electric Logiq E9 with a 3D ultrasound probe. The Doppler settings were adjusted
according to published recommendations with a Doppler frequency of 8.3 MHz and
pulse repetition frequency of 0.4. The same Doppler settings were used for all
examinations. Specific probe positions on the fingers were selected before study
initiation. Two scans were made at each position to minimise the risk of
missing Doppler findings, due to different parts of the cardiac cycle being
sampled as the sweep was made. Each tendon sheath was divided into specific
areas and the visualized 3D Doppler findings in relation to the tendon sheath
were plotted on a schematic drawing (Figure 1A).

Results:

The overall distribution of feeding vessels between
the 2nd and 3rd flexor tendon were comparable and is shown in Figure 1A.

The feeding vessels were predominantly seen at ulnar
and radial locations, except in the distal part of the metacarpal bones, where
the palmar location was common (Figure 1B+C). Palmar vessels were more frequent
distally than proximally in the fingers and the dorsal vessels were extremely
rare.

Conclusion:

Doppler findings in close relation to the tendon
sheaths, due to feeding vessels, were common in flexor tendons of the fingers in
healthy participants and may be a cause of misinterpretation. These vessels
should be taken into consideration when diagnosing tenosynovitis.