The Effect of Contrast Media on HU, CTDI and DLP Values In CT Scan Examination of Blood Vessels to Determine Typical Dose Values

CT-Scan examination in medical diagnostics produces higher radiation compared to conventional X-Ray, especially for certain clinical conditions that require additional contrast media that contribute to higher radiation energy absorbed by the tissue. Contrast media are generally iodine-based which has a high density and absorbs more X-rays, thus increasing the HU value. This study aims to determine the effect of contrast media on Hounsfield Unit (HU), Computed Tomography Dose Index (CTDI), and Dose Length Product (DLP) values to support the determination of Typical Dose Value (NDT). This study uses an experimental quantitative approach by comparing CT-Scan examination data before and after administration of contrast media in a number of patients. HU values are measured in the main blood vessels, while CTDI and DLP were obtained directly from the CT Scanner console. The study sample consisted of 30 abdominal patients and 26 head patients for NDT analysis, including 10 abdominal patients and 10 head patients each used to detect changes in HU values. The results show that the administration of contrast media in CT examinations of the abdomen and head causes a significant increase in Hounsfield Unit (HU) values, namely from 43,53 to 290,58 for the abdomen and from 35,98 to 67,65 for the head. In addition, there is an increase in the Typical Dose Value (NDT) after the use of contrast. The recorded radiation dose parameters are of 5,05 mGy and DLP of 118,13 mGy cm for the abdomen, and of 49,35 mGy and DLP of 1108,30 mGy cm for the head, all of which remain below the Dose Reference Level (DRL) limit. These results confirm that contrast media not only improve image quality by increasing Hounsfield Units (HU), but also affect the amount of radiation dose received by patients. Therefore, optimal scanning parameter settings are needed to achieve a balance between diagnostic image quality and radiation safety.