Background:. Research on the difference of CT Brain noise value with Kernel Filter Variation in case of Lakunar Infark in Radiology Installation of RSUD Sidoarjo. This study aims to determine whether there is a difference in image noise value of CT Brain results in the case of LakunarInfark then know Kernel Filter type which produces the lowest noise value on CT Brain image.Methods: The type of research used is quantitative research with experimental approach done in Radiology Installation RSUD Sidoarjo. Data collection was performed with CT.Brain examination on 25 patients with Lakunar Infarct case, scanning on axial fragment on head area, and reconstruction to 3D image using 3 variations of Filter Kernel H30s smooth, H31s medium smooth +, and H32s Medium smooth FR, then measured Region Of Interest (ROI) in the area of LakunarInfark.Conclusion: Based on data analysis with Friedman method in get significance value equal to 0,001 or p value ? 0,05. This means that there is a significant difference in the average noise value generated on the Kernel Filter variation. The results of the study concluded that the use of Filter Kernel H30s filter medium is the result of noise value in radiograph image CT.Brain in case of LakunarInfark.