Introduction: CT scans of the head and chest organs are common examinations in which the lens of the eye and the breast are exposed to to ionizing radiation, so techniques to reduce the radiation dose are very important. One of the methods to reduce radiation dose is the current pulse modulation technique with additional current reduction in the eye lens and breast area (OBTCM). But it is important to consider how OBTCM dose reduction techniques affect image quality. Purpose: The aim of the diploma thesis is to show how OBTCM affects the dose load in the patient during CT imaging of the head and chest organs, and to demonstrate this also with practical examples. While reducing the radiation dose, we also wanted to find out how OBTCM affects the quality of the images. Methods: We used a descriptive method of data collection with a literature review. We collected sources on the pages of Cobiss, DiKUL, Google Scholar, PubMed, Radiopedia, Science Direct, Springer Link. Results: For 53 CT examinations of the head using OBTCM and 53 examinations with classical current modulation, we observed the exposure parameters, DLP and CTDI, and observed how the quality of the images changes according to the SNR and CNR values. Discussion and conclusion: The results showed that the total radiation dose is higher in OBTCM, but dose to the eye lens and breast is lower. The quality of CT images with OBTCM is comparable to CT images without the use of OBTCM.
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