Electronic Theses and Dissertation

Pemeriksaan Computed Tomography (CT) scan urologi tanpa media kontras merupakan metode diagnostik dengan akurasi tinggi, namun menghasilkan paparan radiasi yang relatif besar sehingga diperlukan optimasi dosis sesuai prinsip As Low As Reasonably (ALARA). Penelitian ini bertujuan menganalisis korelasi faktor eksposi, yaitu tegangan tabung (kVp), arus-waktu tabung (mAs), dan panjang scan, terhadap nilai Computed Tomography Dose Index Volume (CTDIvol) dan Dose Length Product (DLP), membandingkan nilai dosis dengan Diagnostic Reference Level (DRL) BAPETEN 2021, serta mengestimasi dosis efektif dan tingkat risiko radiasi pasien. Penelitian ini menggunakan metode kuantitatif dengan pendekatan observasional analitik terhadap 50 pasien dewasa yang menjalani pemeriksaan CT scan urologi tanpa media kontras di Rumah Sakit Tipe A Banda Aceh. Analisis hubungan antara faktor eksposi dan parameter dosis radiasi dilakukan menggunakan uji korelasi Pearson (Pearson Product Moment Correlation), sedangkan estimasi dosis efektif dihitung berdasarkan nilai DLP dan tingkat risiko radiasi pasien ditentukan berdasarkan kategori dosis efektif. Hasil penelitian menunjukkan bahwa arus-waktu tabung (mAs) berkorelasi positif sangat kuat terhadap peningkatan CTDIvol (r = 0,9396) dan hubungan positif sedang terhadap DLP (r = 0,4111). Panjang scan berkorelasi positif kuat terhadap peningkatan DLP (r = 0,7093), tetapi menunjukkan hubungan negatif sangat lemah terhadap CTDIvol (r = -0,1224) dan arus-waktu tabung (mAs) (r = -0,2328). Peningkatan CTDIvol terutama dipengaruhi oleh arus-waktu tabung (mAs), sedangkan peningkatan DLP dipengaruhi oleh kombinasi arus-waktu tabung dan panjang scan. Nilai kuartil ketiga (Q3) CTDIvol sebesar 13,92 mGy dan DLP sebesar 807,5 mGy.cm masih berada dalam batas DRL BAPETEN 2021. Estimasi dosis efektif rata-rata sebesar 7,90 mSv dengan sebagian besar pasien berada pada kategori risiko radiasi sedang. Dengan demikian, pengaturan faktor eksposi berpengaruh terhadap dosis radiasi dan perlu dioptimalkan untuk mempertahankan kualitas citra diagnostik dengan tetap menjaga keselamatan pasien.
Kata kunci: CT scan, Faktor Eksposi, CTDIvol, DLP, DRL, Dosis Efektif, Urologi, Korelasi Pearson.

Non-contrast urological Computed Tomography (CT) scanning is a highly accurate diagnostic method, however it entails significant radiation exposure, necessitating dose optimization in accordance with the As Low As Reasonably Achievable (ALARA) principle. This study aimed to analyze the correlation between exposure factors specifically tube voltage (kVp), tube current-time product (mAs), and scan length and the Computed Tomography Dose Index Volume (CTDIvol) and Dose Length Product (DLP), to compare these dose values against the 2021 BAPETEN Diagnostic Reference Levels (DRL), and to estimate effective doses and patient radiation risk levels. A quantitative method with an observational analytic approach was employed, involving 50 adult patients undergoing non-contrast urological CT scans at a Type A hospital in Banda Aceh. An analysis of the relationship between exposure factors and radiation dose parameters was conducted using the Pearson correlation test (Pearson Product Moment Correlation), while the effective dose was estimated based on DLP values, and the patient's radiation risk level was determined according to effective dose categories.The results demonstrated a very strong positive correlation between tube current-time product (mAs) and increases in CTDIvol (r = 0.9396), as well as a moderate positive relationship with DLP (r = 0.4111). Scan length showed a strong positive correlation with increases in DLP (r = 0.7093) but exhibited a very weak negative relationship with CTDIvol (r = -0.1224) and tube current-time product (mAs) (r = -0.2328). Increases in CTDIvol were primarily influenced by tube current-time product (mAs), whereas increases in DLP were influenced by a combination of tube current-time product and scan length. The third quartile (Q3) values 13.92 mGy for CTDIvol and 807.5 mGy.cm for DLP, remained within the 2021 BAPETEN DRL limits. The estimated mean effective dose was 7.90 mSv, with the majority of patients falling into the moderate radiation risk category. Thus, exposure factor settings influence radiation dose and require optimization to maintain diagnostic image quality while ensuring patient safety. Keywords: CT scan, Exposure Factors, CTDIvol, DLP, DRL, Effective Dose, Urology, Pearson Correlation.