Dose Monitoring in Radiology Departments: Status Quo and Future Perspectives.

UNLABELLED: The number of computed tomography examinations has continuously increased over the last decades and accounts for a major part of the collective radiation dose from medical investigations. For purposes of quality assurance in modern radiology a systematic monitoring and analysis of dose related data from radiological examinations is mandatory. Various ways of collecting dose data are available today, for example the Digital Imaging and Communication in Medicine - Structured Report (DICOM-SR), optical character recognition and DICOM-modality performed procedure steps (MPPS). The DICOM-SR is part of the DICOM-standard and provides the DICOM-Radiation Dose Structured Report, which is an easily applicable and comprehensive solution to collect radiation dose parameters. This standard simplifies the process of data collection and enables comprehensive dose monitoring. Various commercial dose monitoring software devices with varying characteristics are available today. In this article, we discuss legal obligations, various ways to monitor dose data, current dose monitoring software solutions and future perspectives in regard to the EU Council Directive 2013/59/EURATOM. KEY POINTS: • Automated, systematic dose monitoring is an important element in quality assurance of radiology departments. • DICOM-RDSR-capable CT scanners facilitate the monitoring of dose data. • A variety of commercial and non-commercial dose monitoring software tools are available today. • Successful dose monitoring requires comprehensive infrastructure for monitoring, analysing and optimizing radiation exposure. Citation Format: • Boos J, Meineke A, Bethge OT et al. Dose Monitoring in Radiology Departments: Status Quo and Future Perspectives. Fortschr Röntgenstr 2016; 188: 443 - 450.

Cloud-Based CT Dose Monitoring using the DICOM-Structured Report: Fully Automated Analysis in Regard to National Diagnostic Reference Levels.

PURPOSE: To implement automated CT dose data monitoring using the DICOM-Structured Report (DICOM-SR) in order to monitor dose-related CT data in regard to national diagnostic reference levels (DRLs). MATERIALS AND METHODS: We used a novel in-house co-developed software tool based on the DICOM-SR to automatically monitor dose-related data from CT examinations. The DICOM-SR for each CT examination performed between 09/2011 and 03/2015 was automatically anonymized and sent from the CT scanners to a cloud server. Data was automatically analyzed in accordance with body region, patient age and corresponding DRL for volumetric computed tomography dose index (CTDIvol) and dose length product (DLP). RESULTS: Data of 36,523 examinations (131,527 scan series) performed on three different CT scanners and one PET/CT were analyzed. The overall mean CTDIvol and DLP were 51.3% and 52.8% of the national DRLs, respectively. CTDIvol and DLP reached 43.8% and 43.1% for abdominal CT (n=10,590), 66.6% and 69.6% for cranial CT (n=16,098) and 37.8% and 44.0% for chest CT (n=10,387) of the compared national DRLs, respectively. Overall, the CTDIvol exceeded national DRLs in 1.9% of the examinations, while the DLP exceeded national DRLs in 2.9% of the examinations. Between different CT protocols of the same body region, radiation exposure varied up to 50% of the DRLs. CONCLUSION: The implemented cloud-based CT dose monitoring based on the DICOM-SR enables automated benchmarking in regard to national DRLs. Overall the local dose exposure from CT reached approximately 50% of these DRLs indicating that DRL actualization as well as protocol-specific DRLs are desirable. The cloud-based approach enables multi-center dose monitoring and offers great potential to further optimize radiation exposure in radiological departments. KEY POINTS: • The newly developed software based on the DICOM-Structured Report enables large-scale cloud-based CT dose monitoring • The implemented software solution enables automated benchmarking in regard to national DRLs • The local radiation exposure from CT reached approximately 50 % of the national DRLs • The cloud-based approach offers great potential for multi-center dose analysis.

Dose monitoring using the DICOM structured report: assessment of the relationship between cumulative radiation exposure and BMI in abdominal CT.

AIM: To perform a systematic, large-scale analysis using the Digital Imaging and Communication in Medicine structured report (DICOM-SR) to assess the relationship between body mass index (BMI) and radiation exposure in abdominal CT. MATERIALS AND METHODS: A retrospective analysis of DICOM-SR of 3121 abdominal CT examinations between April 2013 and March 2014 was performed. All examinations were conducted using a 128 row CT system. Patients (mean age 61 ± 15 years) were divided into five groups according to their BMI: group A <20 kg/m(2) (underweight), group B 20-25 kg/m(2) (normal weight), group C 25-30 kg/m(2) (overweight), group D 30-35 kg/m(2) (obese), and group E > 35 kg/m(2) (extremely obese). CT dose index (CTDIvol) and dose-length product (DLP) were compared between all groups and matched to national diagnostic reference values. RESULTS: The mean CTDIvol and DLP were 5.4 ± 2.9 mGy and 243 ± 153 mGy.cm in group A, 6 ± 3.6 mGy and 264 ± 179 mGy.cm in group B, 7 ± 3.6 mGy and 320 ± 180 mGy.cm in group C, 8.1 ± 5.2 mGy and 375 ± 306 mGy.cm in group D, and 10 ± 8 mGy and 476 ± 403 mGy.cm in group E, respectively. Except for group A versus group B, CTDIvol and DLP differed significantly between all groups (p<0.05). Significantly more CTDIvol values exceeded national diagnostic reference values in groups D and E (2.1% and 6.3%) compared to group B (0.5%, p<0.05). CONCLUSION: DICOM-SR is a comprehensive, fast, and reproducible way to analyse dose-related data at CT. It allows for automated evaluation of radiation dose in a large study population. Dose exposition is related to the patient's BMI and is increased by up to 96% for extremely obese patients undergoing abdominal CT.