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Showing 2 results for Diagnostic Reference Levels
Evaluation of diagnostic reference dose levels in CT- scan examinations of adolescence in Tehran: a brief report
R Afzalipour, Sr Mahdavi, H Khosravi, A Neshasteh-Riz, A Fatemeh Hosseini,
Volume 71, Issue 2 (5-2013)
Abstract

Background: Today, a CT scan examination play an important role in disease diagnosis and thus allocates a significant dose of medical X-ray examinations. One of the important principles in the use of ionizing radiations is to observe radiation protection principles. Evaluating patient's absorbed dose and implementing the strategies for reducing dose are prior in safety issues. To achieve this purpose, sufficient studies should be performed in this regard. Therefore, patient's absorbed dose and the factors affecting have been studied in this research. This study aims to present and develop an acceptable level of absorbed dose in CT scan examinations.
Methods: Diagnostic reference dose level in the adult age group (older than 15 years) has been studied in eleven CT scan centers in Tehran. For this purpose, CT scan examinations prevalent in above-mentioned centers were chosen and Weighted Computed Tomography dose index (CTDIw) and dose length product (DLP) parameters were studied. Standard phantoms with 16 and 32 diameters of Polymethylmethacrylate (PMMA) origin have been used in the centers for CT scan calibration process. CTDIw third quartile has been considered as the diagnostic reference dose level (DRL).
Results: Rate of diagnostic reference dose in the adult age group (older than 15 years) for the head, sinus, lungs, abdomen and pelvis are 50.87, 38.27, 8.05 and 9.11 mg, respectively. Dose measurements made in this survey have been used to set up local DRLs and can be used as a template for national DRLs.
Conclusion: Value of diagnostic reference dose for the head examinations is more than the other parts and diagnostic reference dose in Tehran city in the Adult age group and the protocols compared is less than national reference dose.


Determining the diagnostic reference levels (DRL) of CT scan imaging in Saveh Hospitals: a brief report
Mohamad Sarkheil, Mehran Mohseni, Akbar Ali Asgharzadeh , Ali Rasouli Bozcheloie ,
Volume 82, Issue 5 (8-2024)
Abstract
Background: Based on the recommendation of the European Committee and ICRP, DRL values should be determined at the local, national and regional levels for CTDIvol (Computed Tomography Dose Index volume) and DLP (Dose Length Product) dose indicators. According to the radiation protection guidelines, it is essential study has determined DRL in Saveh hospitals
Methods: This study was conducted with two methods based on the results and calculations obtained from the annual Quality Control (QC) reports and the Data Collection (DC) method related to patient scans. In this study, by referring to the annual reports of each device and using radiation components during dosimetry and determining CTDIair or CTDIw, the correction factor was obtained. Using this factor and existing equations, DLP and CTDIvol were calculated based on quality control standards. The second quartile or the median was determined as DRL for head, sinus, chest and abdomen/pelvis imaging protocols and its values were compared with each other and other studies. This study was conducted in February and March 2023 in three hospitals in Saveh city.
Results: The diagnostic reference levels of CTDIvol index were obtained in both QC and DC methods for head (32.76 and 32.36), sinus (11.73 and 9.89), chest (6.06 and 5.11) and abdomen/pelvis (11.86 and 10.56) imaging. The highest DRL values of DLP index in both QC and DC methods are for head, abdomen/pelvis, chest and sinus CT scans, respectively. In the QC method, these values were (603.99), (478.15), (187.15), and (132.65) respectively, and in the DC method, the values were (601.84), (427.76), (219.01), and (114.81) mG.cm.
Conclusion: According to the results of this study and the lack of significant difference between the DRL values of CTDIvol and DLP indicators in both QC and DC methods, it is recommended that the centers, if they have the acceptance criteria for annual quality control, can determine the DRL by referring to the device console information from the DC method.

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