TEXTURE MARKERS AS A MEANS OF EVALUATING THE EFFECTS OF VARIATIONS IN PHOSPHORUS PLATE READING PARAMETERS ON RADIOGRAPHIC IMAGES

• Grant number: 24/04780-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Radiology
• Principal Investigator: Sérgio Lúcio Pereira de Castro Lopes
• Grantee: Vitória Aparecida Amorim Correa
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

This study will aim to use the texture analysis (TA) technique as a tool to assess the influence of the effects of exposure to ambient light and the delay time of scanning digital phosphor plates (PSP) on the quality of the radiographic images obtained by a digital systems - VistaScan Mini View (Durr Dental, Beitigheim-Bissingrn, Germany). Radiographs obtained with standardization of the exposure factors of an aluminum scale of 05 steps, with increments of 0.5mm each, will be taken, considering 02 groups: a) 05 different times for their scans: immediate (zero time or without delay); 10 min; 30 min; 60 min and 120 min; b) 06 times of exposure to light prior to scanning: without exposure to light (immediate scanning, after removing the casing); 5 sec; 10 sec; 30s; 60s and 90s. For each of the considered times, 10 images (repetitions) will be obtained for both groups, with 05 radiographic exposure times (0.10s; 0.20s; 0.32s; 0.40s and 0.50s). The images saved in their bitmap formats will be exported to the MaZda 4.60 software (Institute of Electronics, Technical University of Lodz, Poland), on which the texture analysis will be performed. In this, with the "draw rectangle" tool, 03 regions of interest (ROI) will be determined, standardized, as follows: 1st ROI covering the region with the smallest thickness of the scale (0.5mm) (1st step); 2nd ROI the central region of the scale (1.5mm) (3rd step) and 3rd ROI covering the thickest region of the scale (2.5mm) (5th step). Then, 07 texture parameters, defined by Haralick et al. (1973), will be analyzed using the co-occurrence matrix (COM): Secondary Angular Momentum; Contrast; Correlation; Sum of Squares; Moment of Inverse Difference; Entropy of Sum and Entropy. All texture analyzes will be performed by a previously trained evaluator, dental surgeon, radiologist, with more than 10 years of experience. Exploratory data analysis will be performed using summary measures (mean, standard deviation, minimum, median, maximum, frequency and percentage). Comparison between groups regarding texture parameters will be performed using the Mann-Whitney test. Spearman's coefficient will be used to evaluate the correlation between light exposure and scan time delay with variations in each texture parameter. The significance level adopted will be 5%. It is expected to determine the use texture markers as a quantitative method for determining the effects of exposure to ambient light and the time of postponement of the scanning of phosphor plates in the resulting digital radiographic images.