Optical Tool Matches MRI in Detecting Joint Inflammation

TOPLINE:

Optical spectral transmission (OST) demonstrates a strong correlation with MRI in detecting joint inflammation in patients with inflammatory arthritis, with the best diagnostic performance observed in the wrist joints.

METHODOLOGY:

• Researchers investigated the diagnostic performance of OST in assessing joint inflammation relative to MRI in patients with inflammatory arthritis.
• They included 71 patients with known rheumatic diseases who underwent hand MRI and OST for suspected inflammatory activity (1542 wrist and finger joints) and 114 healthy control individuals with available OST measurements (2508 joints).
• MRI findings were quantified using the Rheumatoid Arthritis MRI Score (RAMRIS), with positive inflammatory signs noted in 51 out of 71 patients.
• Disease activity was assessed using the tender joint count, swollen joint count, and laboratory markers (C-reactive protein and erythrocyte sedimentation rate), with calculation of Disease Activity Score in 28 joints.
• Receiver operating characteristics curves were used to evaluate diagnostic accuracy of OST, while correlation analyses explored relationships between OST and MRI scores, as well as disease activity markers.

TAKEAWAY:

• Patients with MRI-detected inflammation showed significantly higher mean OST scores than those without MRI inflammation or healthy control individuals (all P
• OST demonstrated significant correlations with RAMRIS-synovitis and tenosynovitis scores in the MRI-positive group (correlation coefficient [rho], 0.541; P P = .01, respectively); the correlations were stronger with RAMRIS synovitis score of the wrist, metacarpophalangeal, and proximal interphalangeal joints.
• OST scores showed the highest diagnostic accuracy at wrist joints (area under the curve [AUC], 0.833; 95% CI, 0.700-0.966), followed by proximal interphalangeal (AUC, 0.750; 95% CI, 0.680-0.820) and metacarpophalangeal joints (AUC, 0.723; 95% CI, 0.634-0.812).
• Significant correlations were observed between OST and clinical disease activity parameters, including tender joint count (rho, 0.333; P = .013) and swollen joint count (rho, 0.308; P = .017) in patients with MRI-detected inflammation.

IN PRACTICE:

“We believe OST can be considered a complementary tool to MRI and other established diagnostic methods,” the authors wrote.

SOURCE:

The study was led by Konstantinos Triantafyllias, MD, PhD, and Mohammed Alhaddad, Acute Rheumatology Centre Rhineland-Palatinate, Bad Kreuznach, Germany. It was published online on January 30, 2025, in Arthritis Research & Therapy.

LIMITATIONS: 

The retrospective study design could have led to selection bias. Subgroup analyses of the different types of inflammatory arthritis other than rheumatoid arthritis were not performed. Similarly, the diagnostic utility of OST in patients with inflammatory arthritis but negative inflammatory activity on MRI was not investigated. OST primarily measures light absorption in the blood flow in joints, thereby making it less anatomically specific than ultrasonography and MRI.

DISCLOSURES:

The study was supported by Projekt DEAL. The authors reported no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.