Radiation dose and diagnostic reference level for certain computed tomography angiography procedures

Medical X-rays are the most significant artificial source of public exposure to ionizing radiation. While the advantages of Computed Tomography (CT) are widely acknowledged in precise diagnosis, such benefits are not risk-free. CT is a device with increased patient exposure compared to conventional radiation techniques. This study aims to evaluate radiation doses to patients from Computed Tomography (CT) examinations in Riyadh Care hospitals and define diagnostic reference level (DRL). Methods: Patient-related data on CT protocol for five standard CT examinations, including chest and abdomen angiography, were collected. The patient's exposure was calculated using a Computed Tomography instrument (Siemens Somatom Sensation 128 (128-MDCT)). Then, Volume Computed Tomography Dose Index (CTDI_vol) and Dose Length Product (DLP) were calculated. Results: The CTDI_vol (mGy) for chest and abdomen angiography ranged (10.79 – 46.63), (5.52 – 24.01), respectively. Values of DLP (mGy.cm) had a range of (280.6 – 1830.73), (299.08 – 1302.68) for chest angiography and abdomen angiography, respectively. The proposed quantity for DRL is the third quartile of CTDI_vol, derived from dose distribution for each examination. Conclusions: This study's results demonstrated large doses for the same examination among different centers. For all examinations, our values were lower than international reference doses. (author)