Patient and staff dosimetry in neuroradiological procedures

Cerebral angiography provides valuable information for use in the clinical management of patients but can result in relatively high radiation doses to patients and staff due to the extended fluoroscopy time and number of images acquired during an examination. In this study, extremity doses to radiologists and scrub nurses working in a neuroradiological centre were monitored during a 3 month period using thermoluminescent dosemeters (TLDs). Electronic personal dosemeters were also used to monitor doses above the lead apron at chest height to the radiologists, radiographers and the scrub nurses. Patient doses were recorded using a dose-area product meter whilst patient thyroid dose was measured using TLDs. Two types of examination were studied: cerebral angiography and arterial embolization. It was deduced from the results of the study that the radiologist may expect to receive a mean dose above the lead apron at chest height of 11 microSv and 25 microSv per examination when performing cerebral angiography and arterial embolization, respectively. A radiologist mean hand dose of 19.3 microSv per examination was found, whilst the average eye dose for both radiologist and scrub nurse was 13.4 microSv per examination. The patient dosimetry results revealed a mean thyroid dose of 1.7 mSv and a dose-area product of 48.5 Gy cm2 for cerebral angiography. Average dose-area product for arterial embolization was 122.2 Gy cm2 along with a mean patient thyroid dose of 3.3 mSv. More detailed patient dosimetry was also performed using a Rando anthropomorphic phantom loaded with TLDs to measure organ doses and hence estimate effective dose. A typical four vessel angiogram was found to result in a patient effective dose of 3.6 mSv.