Assessment of compliance levels of effective doses in pediatric CT

Document Type: Conference Proceedings

Authors

1 PhD, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences (International Campus), Tehran, Iran.

2 MSc, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences (International Campus), Tehran, Iran.

Abstract

Introduction: Computed tomography (CT) is a medical imaging modality that produces 3-D cross-sectional images of tissues using several X-ray projections at different angles. Since its introduction in the 1970s, CT usage has been on the increase for both adults and pediatrics. A major challenge of this modality is the high doses of radiation exposure to patients, especially in pediatrics, who are more radiosensitive compared to adults. Hence, the need to ensure that radiation safety standards are adhered to. This will go a long way in reducing the adverse effects of radiation. The aim of this study was to assess the level of compliance to international dose reference levels (DRLs) in terms of effective doses in pediatric CT scans conducted in three Iraqi hospitals.
Materials and Methods:
CT brain and abdomen/pelvis examinations were conducted for pediatric patients aged between few months and 15 years in three Iraqi hospitals (Al Wasiti, Neuroscience and Al Omara). All scans were performed on a Somatom Sensation® 16 multidetector CT (MDCT) scanner with a Straton® X-ray tube (Siemens, Erlangen, Germany) utilising automatic tube current modulation (CARE Dose4DTM; Siemens, Erlangen, Germany). Volumetric CT dose index (CTDIvol) and dose length product (DLP) were collected for 180 patients (60 in each hospital). Afterwards, their effective doses were estimated from DLP values and compared with international DRLs.
Results: Brain CT: The DLP values obtained for Al Wasiti, Neuroscience and Al Omara hospitals were in the range; 789-918.8 mGy.cm, 833-874.6 mGy.cm and 627.6-810 mGy.cm respectively, while their corresponding effective doses were in the range; 1.8-2.09 mSv, 1.9-
2.06 mSv and 1.43-1.83 mSv.
Abdomen/Pelvis: The DLP values obtained for Al Wasiti, Neuroscience and Al Omara hospitals were in the range; 392.9-425.8 mGy.cm, 355-395 mGy.cm and 314.8-383.6 mGy.cm respectively, while their corresponding effective doses were in the range; 6.65-7.22 mSv, 6-
6.7 mSv and 5.34-6.51 mSv. Using the International Commission on Radiological Protection (ICRP) publication 103 as basis for assessing compliance level, for brain CT we observe slightly higher values in Al Wasiti and Neuroscience hospitals while Al Omara was similar to the international DRLs. However, for abdomen/pelvis CT examinations, the effective doses in all three hospitals were within the acceptable limits of international DRLs.
Conclusion: This study has shown an encouraging level of compliance towards adequate radiation protection management in pediatric CT examinations among the three hospitals. Although, the best compliance level was observed in Al Omara hospital. Regular monitoring should be enforced to ensure that CT doses delivered to pediatric patients are as low as reasonably achievable without compromising diagnostic quality.

Keywords