THESIS, 2023 FERDI WIJAYANTO ANALYSIS OF CT NUMBER AND NOISE VALUES BEFORE AND AFTER CALIBRATION AS QUALITY CONTROL PROGRAM OF CT SCAN MACHINE 5 Chapters + 48 Pages + 23 Images + 8 Tables + 9 Attachments Background of Research: Technically, in order to ensure the quality of CT scan image can be accordingly guaranteed, as well as to keep the radiation dose below the specified limits, a qua…