Colour analysis of the equine endometrium: comparison of spectrophotometry and computer-assisted analysis of photographs within the L*a*b* colour space system.

This study aimed to compare two different methods of quantifying the colour of the inner surface of a horse’s uterus, relating the results to signs of inflammation and fibrosis. The two methods used were a spectrophotometer and computer-assisted analysis of photographs.

Methods

• The study involved the examination of the mucosal surfaces of 17 horse uteruses, which were acquired from an abattoir.
• These surfaces were evaluated using two methods: a spectrophotometer (an instrument that measures the intensity of light) and a computer-assisted analysis of photographs method.
• Both methods had their values converted into L*a*b* colour space–a color-opponent space with dimensions L* for lightness and a* and b* for the color-opponent dimensions.

Findings

• The study found that although there was a significant correlation between the two methods, variations were noted in ‘brightness’, ‘red’ and ‘yellow’ values.
• Within a single uterus, the measurements using the spectrophotometer didn’t vary significantly.
• However, when using photographic analysis, differences in brightness were noted between the uterine horns, though there were no differences detected in chromaticity (the quality of a color regardless of its luminance).
• Moreover, both methods found that extensive fibrosis (the thickening and scarring of connective tissue) was associated with increased brightness and decreased chromaticity.
• Inflammation was associated with reduced chromaticity as measured by the spectrophotometer, and reduced brightness and yellow values when assessed through photography.

Implications

• These findings suggest that either of these color analysis techniques could be useful in identifying inflammation or fibrosis in the uterus of a horse.
• For widespread acceptance of this technique as a diagnostic tool (such as endoscopic evaluation of uterine mucosa in vivo), standardized illumination techniques will be needed. This is because different types and levels of illumination can affect the perceived color, making it essential that a standard light source is used for accurate color comparison and interpretation.