Patient effective dose estimation for routine computed tomography examinations in Iran

Determination of Diagnostic Reference Level (DRL) in Common Computed Tomography Examinations with the Modified Quality Control-Based Dose Survey Method in Four University Centers: A Comparison of Methods

“…This difference shows an ascending trend in all examinations (Table 4). Also, in the present study, the DRL result is closer to the NDRL obtained for CTDI vol with QC than the DC and Di methods used in NDRL study conducted by Najafi et al [18], and Deevband et al [22] studies, respectively. In another study, besides the QC method, the dual purpose quality control method was used for DRL calculation of five CT scanners by changing the QC method in Shiraz, but the centers were not identified [23].…”

“…The sinus examination is not included in the study which was conducted by Kanal et al [20]. A comparison of DRL based on CTDI vol and DLP in the present study with the QC and MQC methods performed by Deevband et al [22], based on the protocols in the four common CT scan examinations with 120 devices in Iran (400 patients) using Di method, revealed the underestimation of the dose indices. The difference between the third quartile of DRL based on CTDI vol in this study and the four head, sinus, chest, and abdomen/pelvis examinations was 13.7%, 50%, 40%, and 42.1%, respectively (Table 5).…”

“…All these differences in calculating LDRL and NDRL by QC methods in comparison to this study could be attributed to the scan pa- Deevband et al [22] and Sohrabi et al [23]. The year mentioned in the table for each study is the study year, and the numbers in parentheses show the number of computed tomography (CT) scanners in each study.…”

“…An American study conducted by Kanal et al [20] is the only study, used the SSDE method to measure NDRL. Based on the measurement of the water equivalent diameters of the CT images of the organs of 1,300,000 patients, which obtained from the National Radiology Data Registry (NRDR) through ACR, NDRLs with normalized CTDI vol of the 16-and 32- [21,23], Deevband et al [22], respectively. The MQC, QC, DPQC, DC and Di stand for: modified quality control based, quality control based, dual purpose quality control based, data collection and direct methods, respectively.…”

“…Figure 4: The diagram shows diagnostic reference levels (DRL) of four routine examination based on the volume computed tomography dose index (CTDI vol ) calculated with different methods in this study and the national and local studies conducted by Parsi et al [11], Najafi et al [18], Sohrabi et al [21, 23], Deevband et al[22], respectively. The MQC, QC, DPQC, DC and Di stand for: modified quality control based, quality control based, dual purpose quality control based, data collection and direct methods, respectively.…”