Radiation Dose Estimates in CT Coronary Angiography

"nThe coronary artery disease is a common and major cause of death. Invasive coronary angiography is currently the "gold standard" investigation to detect obstructive coronary artery lesions but carries a small risk of serious complications. "nThe mortality risk of invasive coronary angiography (ICA) is about 0.13% which is approximately twice the risk of multi-detector CT (MDCT) angiography (0.07%). MDCT angiography has enabled the detection of coronary artery disease noninvasively. The measured mean effective dose has been measured to be significantly higher in past studies. MDCT angiography radiation dose was clearly more than that of ICA, which has led to a concern about the increasing use of MDCT angiography. Since there was not any study about the radiation dose in patients doing MDCT angiography in Iran and according to the importance of this subject, we performed a study in 134 patients referred for MDCT angiography of the coronary arteries in one of the biggest MDCT angiography centers, using 64-slice MDCT (SIEMENS SOMATOM Sensation 64). The patients were divided into two groups, with or without a previous history of CABG. Total mean effective dose and CTDI were 15.24 mSv and 51.80 mSv, respectively that were similar to previous studies in other parts of the world. Measured quantities were higher in patients who had a history of CABG (20.92 mSv and 13.99 mSv). Our study shows that if the scanning parameters are adjusted for the patient, the radiation dose could be reduced down to 50%.