MATLAB Tool for Color Comparative Analysis in Fixed Specimens. A Five Solution Single Blind Controlled Trial

Abstract

Formaldehyde fixation avoids decomposition process of cadaveric specimens 1, making them useful for anatomy teaching and research 2. However, formaldehyde leads to fresh appearance loss in the tissue, which reduces its academical value. Although some color recovery solutions have been presented 3, 4, no standardized method for quantitative color assessment in fixed tissues has been proposed. Our aim of is to present a MATLAB tool for color recovery analysis in formaldehyde fixed tissues. Four different animal tissues (cardiac and skeletal muscle, kidney and liver), previously fixed with 10% formaldehyde (v/v) were treated in five different solutions (mineral staining, sodium bisulfite, sodium bicarbonate, GERDEX and modified Chilean solution 3). Tissues were photographed at different stages of preservation. Analysis was carried out in two different spaces of chromatic representation (RGB and HSV). A computerized color comparison tool was developed allowing visualization of the chromatic presence in RGB color space through a three‐dimensional distribution (color cloud). Besides color cloud intersection percentage, frequency histograms of RGB distributions and the color saturation (S) distribution were used to generate performance metrics based on the Bhattacharyya distance. Each metric addressed one specific desired characteristic of a color recuperated specimen. Mineral staining proved to be the solution with the best overall performance across most of the proposed metrics, significantly recovering the color compared to fresh tissue. Although significant results were obtained, future works implementing more robust methods of comparison, that involve metrics based on multiple desirable characteristics of a specimen are necessary. The MATLAB tool developed showed to be useful for the quantitative color analysis and comparison in formaldehyde fixed tissues. Further studies should be done to standardize quality metrics of existing and upcoming preservation techniques. Support or Funding Information Anatomy Laboratory, School of Medicine, Universidad de los Andes. Human body preservation - old and new techniquesE.BrennerJ Anat.224331644Dissection laboratory is vital to medical gross anatomy educationNA.GrangerAnat Rec.281B168Congreso colombiano de morfología: Empleo de solución fijadora conservadora chilena como alternativa al uso del formaldehido para la preservación de tejidosJDRojas OviedoSRuiz DiazVsofiaInt J Morphol.28133740Die Konservierung ganzer Leichen in natürlichen FarbenW.ThielAnn Anat - Anat Anzeiger.174318595