Analysis of the Relationship between Image Noise Value and Computed Tomography Dose Index (CTDI) on Pitch Variation of Routine Abdominal CT Protocol at Koja Regional Hospital, North Jakarta

Abstract

Computed Tomography (CT) has become one of the primary diagnostic methods in modern medicine, allowing detailed and accurate visualization of the internal structures of the human body. In its use, the pitch value can affect the radiation dose received by the patient and the quality of the resulting image. This study aims to analyze the effect of pitch variations on the Computed Tomography Dose Index (CTDI) and image noise in Routine Abdominal CT to achieve the best image quality with minimal patient dose. This research method uses a quantitative design using a 32 cm diameter PMMA water phantom as a model. Eight pitch variations (0.40, 0.55, 0.60, 0.80, 0.90, 1.00, 1.35, and 1.50) were evaluated using a Siemens Somatom Perspective 128 Slice CT-Scan. Data were collected through experiments on the water phantom and analyzed using descriptive analysis, normality tests, and correlation tests. The results showed no significant relationship between CTDI values and image noise with pitch variations. Increasing the pitch value contributed to increasing CTDI but decreased image noise. These results indicate that a pitch of 0.60 has an optimal image noise value and minimal CTDI in the Routine CT Abdomen protocol at RSUD Koja, North Jakarta. This study provides a deeper understanding of the importance of selecting the correct pitch value in minimizing patient radiation dose while maintaining good image quality. The practical implication is using a pitch of 0.60 as the optimal value for the Routine CT Abdomen protocol, which can reduce the risk of excessive radiation exposure to patients. Keywords: CT-Scan, pitch, water phantom, CT Abdomen, noise, computed tomography dose index (CTDI)