A Chinese University medical team has pioneered the use of high-resolution peripheral quantitative computed tomography (HR-pQCT) and three-dimensional imaging to track bone erosion in people with rheumatoid arthritis. The findings suggest the scans may help distinguish very small erosions, which can also occur in healthy people, from larger lesions more likely to be associated with the disease.
The study examined erosion around the head of the second metacarpal bone and compared patients with 78 healthy participants. At baseline, erosions smaller than 1 cubic millimetre were found in 29% of patients and 26% of the healthy group. The distribution of these erosions did not differ significantly between the two groups.
Erosions larger than 5 cubic millimetres were found in 17% of patients, compared with 3% of healthy participants. The Ming Pao report said HR-pQCT may help rule out non-inflammatory explanations for very small erosions and identify changes more likely to be linked to rheumatoid arthritis.
During scanning, the patient's hand is secured in place. One report said the procedure takes about three minutes. The supplied evidence does not establish HR-pQCT as a routine clinical tool or provide direct data comparing its performance with X-rays, ordinary CT scans or magnetic resonance imaging.
The team followed 247 rheumatoid arthritis patients with imaging for up to eight years. Of these, 149 continued to receive usual treatment, while 98 people whose symptoms had begun less than two years earlier received strict target-based treatment during their first year after diagnosis before switching to usual care.
Target-based treatment was described as adjusting an individual treatment plan according to disease activity and agreed treatment goals. During follow-up, more than half of the patients diagnosed with large erosions showed improvement. Among patients with small erosions, 14% improved and most remained stable.
An i-CABLE report said a team postdoctoral researcher found that target-based treatment made bone-erosion repair nearly seven times more likely than usual treatment. The supplied evidence does not show how many patients this estimate covered, its statistical significance or confidence interval. It also does not establish whether “repair” refers to a reduction in erosion volume on imaging or to improvements in symptoms or joint function.
The team plans to study HR-pQCT for earlier rheumatoid arthritis assessment and develop imaging-based risk stratification. The proposed work would aim to identify symptom-free people or newly diagnosed patients at higher risk. Further research is needed before the technique can be considered part of a standard clinical pathway.