Radiation dose to patients and staff during angiography of the lower limbs. Derivation of local dose reference levels
Received 14 November 2007; received in revised form 26 February 2008; accepted 27 February 2008. published online 07 April 2008.
Abstract
Background
The Euratom directive 97/43 recommends the use of patient dose surveys in diagnostic radiology and the establishment of reference dose levels (DRLs).
Purpose
To perform measurements of the dose delivered during diagnostic angiography of the lower limbs using thermoluminescence dosimeters (TLDs), extraction of DRLs and estimation of the effective dose and radiation risk for this particular examination.
Methods
Dose measurement was performed on 30 patients by using TLD sachets attached in 5 different positions not only on the patient, but also to the radiologist. All the appropriate factors were recorded. Measurement of the ESD was performed after each examination.
Results
The mean entrance skin dose (ESD) was calculated to be 70.8, 67.7, 24.3, 18.4, 9.7mGy at the level of aorta bifurcation, pelvis, femur, knees, and at feet, respectively. The average effective dose is 9.8mSv with the radiation risks for fatal cancer to be 5.4×10−4. The effective dose of the radiologist was calculated to be 0.023mSv per procedure.
Conclusion
Radiation dose variation depends on the physical characteristics of the patient, on the procedure preferences by radiologists and the difficulties in conducting procedures. The main reason for the increased patient dose, compared to other studies, is the number of frames rather than the duration of fluoroscopy. For DSA of the lower limbs, the DRL was chosen to be an entrance skin dose of 96.4mGy in the pelvic region. The dose to the radiologist is negligible.
ABSTRACT