A Study on the Optimization of Contrast Enhancement in Cerebrovascular CT in Hemorrhagic Stroke Patients

During the brain computed tomography angiography (Brain CTA) test of hemorrhagic stroke patients, we tried to find out the test method for optimizing contrast enhancement of cerebrovascular vessels by changing the location of the region of interest (ROI) and scan delay time. From September 2022 to February 2023, 80 patients who visited the emergency room and performed a Brain CTA test were tested, and 10 people in control group without disease were ROI set at C3 to C4 level and performed a test by 6-second delay scan as soon as contrast enhancement was performed on common carotid artery (CCA) with the naked eye. 40 people in the hemorrhagic stroke experiment group A setting the same test method as the control group were tested after A-0; 6 second, A-1; 8 second, A-2; 10 second, A-3; 12-second delay for 10 people each, and 30 people in experiment group B setting ROI at circle of willis level and as soon as contrast enhancement was performed in the middle cerebral artery (MCA) were tested after B-1; 2 second, B-2; 4 second, B-3; 6-second delay for 10 people each. The evaluation methods include quantitative evaluation that compares and analyzes the mean HU values and percentage values of internal carotid artery (ICA), MCA, superior sagittal sinus (SSS), and internal jugular vein (IJV) of the control group and experimental groups A and B, qualitative evaluation through reconstructed images, and significance evaluation was conducted using an independent sample t-test. As a result of the quantitative evaluation, the mean HU value of MCA in the experimental group was measured lower than that of the control group, 369 HU, but was generally close to 300 HU. In the MCA vs SSS percentage value, the experimental group B-2 was 0.7%, the closest value to the control group. As a result of the blind test through reconstructed images as a qualitative evaluation, the control group scored the highest with 16 points, and in the experimental group B-2 scored the highest with 15 points. As a result of significance evaluation through an independent sample t-test, the p-value of the control group and the experimental group B-2 was 0.408, which was evaluated as having no significant difference, and other experimental groups were evaluated that there was a significant difference. As a result of analyzing the test performed by changing the ROI position and scan delay time of control and experimental groups A and B, setting the ROI at the circle of willis level and testing after 4-second delay as soon as contrast enhancement is made in MCA will be useful for Brain CTA test in hemorrhagic stroke patients.