Computed tomography radiation dose in a regional survey. (September 2016)

• Record Type: Journal Article
• Authors: Serna, A.; Garcia-Angosto, E.A.; Garcia-Sanchez, A.J.; Garcia-Sanchez, F.; Ramos, D.
• Is Part Of: Physica medica. Volume 32(2016)Supplement 3
• Page Start: 287
• Publication Date: 2016-09
• Subjects: Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2016.07.106
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract : Purpose: To evaluate the patient dose in computed tomography (CT) examinations and contribute to the stablishment of dose reference levels using a dose management system. Material and methods: Data from 5 CT hellical multi-slice scanners (16–128 slices) in 3 public hospitals were surveyed (4 Siemens, 1 General-Electric) during 3 months. Three typical examinations were selected: head (1445 cases), thorax (579 cases) and abdomen-pelvis (1055 cases). GE-Dosewatch was used to register patient dose indexes, CTDIvol and DLP, and the technical parameters. The statistical analysis was done in Matlab. Results: Both the CTDIvol and the DLP data approximate well to a log-normal distribution function whereas the scanned length fits better to a normal distribution. Median CTDIvol of head scans ranged 33.0–63.8 mGy, thorax 6.7–9.7 mGy and abdomen-pelvis 10.0–12.1 mGy. Median DLP of head scans ranged 527–1162 mGy cm, thorax 218–334 mGy cm and abdomen-pelvis 383–453 mGy cm. We noticed that same CT model scanners use different technical examinations parameters, resulting in dose variations up to 30%. A dose optimization process was initiated to standardize the scanning protocols, thus expecting a dose reduction around 20% in some cases. Patient size selection was not deemed necessary due to the high number of cases per examination, more than 100. A drawback of this massive data is the presence of extreme outliers, and thus data filtering is mandatory. Conclusion: Dose management systems provide an efficient tool to overview and optimize radiological dose levels. Disclosure: None.