Nilai Contrast to Noise Ratio (CNR) Radiograf Thorax PA antara menggunakan Grid dengan tanpa Menggunakan Grid

Background: Chest radiographic examination often does not use a grid even though the thorax is an object that has a thickness of more than 10 cm so it must use a grid. This study aims to determine the differences and the degree of change in Contrast to Noise Ratio on PA radiographs between using a grid and without using a grid.Methods: This type of research is a pre-experimental quantitative. The research subject is a radiological image of PA thorax made using the grid (50 patients) and without using the grid (patient). The image is analyzed by pixel value using Dicom softwareResults: There is a difference in contrast values on the PA radiographs between those using the Grid and without using the Grid (p-value 0.001). The average value of the contrast on the chest radiograph using a Grid is 2283.60, while the one without using a Grid is 1878.58. Noise value also shows that there is a difference between chest radiographs of PA images using Grid without using Grid (p-value = 0.001). The average thorax photo noise using Grid is 25.32, paired using Grid is 17.84. Statistical test on the value of Contrast to Noise Ratio (CNR) shows that there is a difference between radiographs of PA chest radiography using Grid without Grid (p-value 0.001). The average CNR radiograph of the PA thorax PA using Grid is 100.79, while the CNR value of the radiograph of thorax PA without using Grid is 125.62.Conclusions: There is a Contrast difference between using a grid and without using a grid (p-value 0.001). There is a Noise difference in PA radiographs between using a grid and without using a grid (p-value = 0.001). There is a difference in Contrast to Noise Ratio on the PA chest radiograph between using a grid and without using a grid (p-value 0.001).