A radiopharmaceutical technique can be used as an objective tool to diagnose Raynaud’s phenomenon (RP) and differentiate between primary and secondary RP, according to a study published in the journal Rheumatology International.
The study, titled “Diagnosis of Raynaud’s phenomenon by 99mTc-pertechnetate hand perfusion scintigraphy: a pilot study,” distinguishes between primary Raynaud’s phenomenon, the most common form and one not connected to underlying conditions, and secondary RP, which is associated with diseases such as scleroderma (systemic sclerosis), lupus (systemic lupus erythematosus), and rheumatoid arthritis.
The technique, called hand perfusion scintigraphy, uses 99mTc-pertechnetate, a radioactive compound that is often used for medical imaging. It is a non-invasive and cost-effective test that lasts just 10 minutes, and that can detect abnormalities in blood flow in the hands. It can also be used to evaluate how well a patient responds to treatment.
To assess its usefulness, a team of researchers led by Professor Vera Artiko of the University of Belgrade in Serbia recruited 53 people, 18 of whom had primary RP, 25 who had secondary RP associated with systemic sclerosis, and 10 who were healthy controls.
Researchers injected 99mTc-pertechnetate in the forearm of participants and recorded blood flow and blood pool in the hands using a special camera called a gamma, or scintillation, camera that captures gamma radiation emitted from radioisotopes.
The team then calculated the ratio of the dynamic blood flow and of the static blood pool in the palms of the hands versus the fingertips. They found that there were statistically significant differences between the three groups; the dynamic study, which assesses blood flow, could separate healthy individuals from RP patients, whereas the static study, which assesses blood pool, could separate primary from secondary RP.
“Our method is able to differentiate between patients with normal and those with abnormal microcirculation of the hands,” the researchers concluded
In the past, RP has been diagnosed based on patients’ description of their symptoms, as well as through the induction of visible RP, such as color changes in the fingers in response to cold water. However, these are not objective measures and have not been successful in routine clinical settings.
More recently, radioisotopes have been used to diagnose RP, and several studies have shown the effectiveness of this approach. However, up to now, these were not able to differentiate between primary and secondary RP. According to the authors, further research with a larger number of participants is required to confirm the usefulness of this approach.