Quantifying Digital Ulcers in Systemic Sclerosis: Reliability of Computer-Assisted Planimetry in Measuring Lesion...

Area of Science:

• Rheumatology
• Dermatology
• Medical Imaging

Background:

• Digital ulcers are a significant complication in systemic sclerosis (SSc), causing pain and functional impairment.
• Slow healing and infection risk in SSc digital ulcers can lead to severe outcomes, including amputation.
• There is a need for reliable, objective methods to assess digital ulcer progression and healing in clinical and research settings.

Purpose of the Study:

• To compare two computer-assisted planimetry methods (ellipse and freehand regions of interest [ROIs]) for measuring digital ulcer area from photographs.
• To evaluate the reliability of photographic calibration and the chosen measurement methods for SSc digital ulcers.

Main Methods:

• Photographs of 107 digital ulcers from 36 SSc patients were analyzed by three raters.
• Custom software was used for photographic calibration and drawing ellipse or freehand ROIs.
• Intraclass correlation coefficients (ICCs) were calculated to assess intrarater and interrater reliability.

Main Results:

• Photographic calibration demonstrated excellent intrarater reliability (ICC = 0.99).
• Both ellipse and freehand ROIs showed high intrarater reliability (0.97 and 0.98, respectively).
• Interrater reliability was also strong for both methods (0.77 for ellipse, 0.76 for freehand).

Conclusions:

• Computer-assisted planimetry is a highly reliable method for assessing SSc-related digital ulcers.
• These objective measurement techniques show promise for use as outcome measures in clinical trials.
• Further validation is needed to implement these methods in routine clinical practice for systemic sclerosis patients.