Evaluasi Tata Laksana Pemeriksaan CT Scan Kepala: Efek Miscentering Pada Dosis Lensa Mata dan Kualitas Citra

Improper patient position in the isocenter position can interfere with optimization efforts. This study aimed to evaluate the management of head CT scans by knowing the effect of miscentering on the eye lens dose and noise. We used a water phantom and patient image and conducted a retrospective study of 1025 patients. Doses were calculated using IndoseCT software, while noise and miscentering were calculated using IndoQCT software. The difference in the right and left eye lens doses was tested using the student's t-test. The water phantom's position is above and below the isocenter of ±10, ±20, and ±30 mm. While the patient is correct at the center of the gantry (isocenter), the laser marker is between the patient's eyes and the symphysis pubic, and the height of the table is adjusted to the patient's center of mass. The vertical miscentering rate (posterior-anterior) is around 67.8%, with a miscentering range from -30 to -21 mm. There was no significant difference between the right and left eye lens doses (P-value > 0.05). The eye lens dose increases as the phantom or patient position decreases from the isocenter and decreases as the phantom or patient position increases from the isocenter. Likewise, with noise, it increases as the phantom or patient position increases from the isocenter and decreases as the phantom or patient position decreases from the isocenter. Miscentering above the isocenter position can potentially reduce the eye lens dose. Keywords: Miscentering, Eye lens dose, noise