CT DRL value for adult patients in a University Hospital from Brazil

Congress:

EuroSafe Imaging 2019

Poster Number:

ESI-0052

Type:

EuroSafe Imaging

Keywords:

Action 2 - Clinical diagnostic reference levels (DRLs), Radioprotection / Radiation dose, Radiation physics, CT, Radiation safety, Quality assurance

Authors:

C. M. de Oliveira, A. Turcati Accorsi, L. Vinicius de Moura, A. Bacelar, M. ANÉS

DOI:

10.26044/esi2019/ESI-0052

DOI-Link:

https://dx.doi.org/10.26044/esi2019/ESI-0052

Fig. 1: CTDIvol per scan of Chest-W, Chest-ED, Abdomen-W and Abdomen-ED groups.

Fig. 2: DLP per scan of Chest-W, Chest-ED, Abdomen-W and Abdomen-ED groups.

Fig. 3: Head group CTDIvol per scan for each CT scanner.

Fig. 4: Chest-W group CTDIvol per scan for each CT scanner.

Fig. 5: Abdomen-W group CTDIvol per scan for each CT scanner.

Background/introduction

Computed Tomography (CT) is a very important tool for diagnostics in many fields of medical expertise. Organisation for Economic Co-operation and Development data shows that in most countries CT exams have doubled in the last decade [1]. This recent scenario has pointed CT as the imaging modality that compromise about half the radiation dose on medical exposures [2;3] making the medical community aware of the need for optimized use of this resource. Diagnostic Reference Levels (DRL) are defined in ICRP 135 as a form of...

Description of activity and work performed

Our Radiology department has three CT scanners models from different brands with angular and longitudinal tube current modulation, no iterative reconstruction, but distinct detector collimation: 64 channels, 16 channels and 8 channels. For convenience we will name them as CT64, CT16 and CT8, respectively. We collected acquisition parameters and dose information from randomly selected examinations, totalling 510 CT exams (70 head exams, 50 chest exams and 50 abdomen exams for each CT scanner) scanned on 2018 accounted only for patients over 18 years and without...

Conclusion and recommendations

Local DRLs were determined for Head, Chest and Abdomen exams in a university hospital from Brazil. Two methodologies were considered to determine DRL, setting the standard patient using the patient’s weight and using the patient’s effective diameter. CTDIvol and DLP median and 75th percentile found were similar for the two methods, suggesting that both can be used for patient standardization. Even though effective diameter considers the irradiated anatomy and weight is one of many quantities related to the patient’s body type, weight is a more...

Personal/organisational information

Mr Christian Mattjie de Oliveira Medical Physicist Resident Radioprotection and Medical Physics Department Hospital de Clínicas de Porto Alegre, Porto Alegre (Brazil) [email protected]

References

1. OECD (2019). Computed tomography (CT) exams (indicator). doi: 10.1787/3c994537-en (Accessed on 02 January 2019) 2. Hart, D., et al (2010). "Frequency and collective dose for medical and dental X-ray examinations in the UK, 2008." Health Protection Agency. 3. Mettler Jr, Fred A (2008). et al. "Medical radiation exposure in the US in 2006: preliminary results." Health physics 95.5: 502-507. 4. ICRP (2017). “Diagnostic reference levels in medical imaging”. ICRP Publication 135. Ann. ICRP 46(1). 5. Ministério da Saúde, Secretaria de Vigilância em Saúde (1998)....