Estimate radiation dose and cancer risk in adult computed tomography angiography for upper and lower extremity CT procedure

Introduction: The use of computed tomography (CT) for diagnostic evaluation has increased dramatically over the past two decades. Even though CT is associated with substantially higher radiation exposure than conventional radiography, limited data are available worldwide. We sought to estimate the radiation dose associated with common CT studies in clinical practice and quantify the potential cancer risk associated with these examinations. Methods: The researchers conducted a retrospective cross-sectional study describing radiation dose associated with the two common types of diagnostic CT studies (upper and lower CT angiography). The researchers estimated lifetime attributable risks of cancer by study type from these measured doses. 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 for upper and lower extremity had ranged (1.16 – 7.16) and (2.57 – 14.81), respectively. Values of Dlp had a range of (100.88-662.87) and (167.96 – 1545.15) for the upper and lower extremities, respectively. Conclusion: Radiation doses from commonly performed diagnostic CT examinations are higher and more variable than generally quoted, highlighting the need for greater standardization across institutions. Radiation doses varied significantly between the different types of CT studies. (author)