The use of bismuth protection becomes important as it allows to minimize interaction of ionizing radiation on the human body, absorbing the low energy photons, and lowering the possible biological effects in the most radiosensitive organs. So, the main goal it was to assess the viability of bismuth breast shield in thorax CT scans by determining the percentage of dose reduction obtained in the phantom in different configurations and to evaluate the image quality, such as the HU value, low and high contrast resolution, noise...

It were performed 135 measurements in a 16-slice CT Scanner, without and with bismuth breast shields, in different configurations: with protection but without sponge, with protection with a sponge, with protection with two sponges and the bismuth protection attached to the detectors window at the gantry. Dose measurements on phantom (Cardinal Health 76 415) with an ionization chamber were performed using the routine thorax CT protocol. Image quality control tests were performed using the phantom (Gammex 464) with and without bismuth breast protection in different...

Dose Indices rating This study evaluated the dose rate for the routine Thorax protocol, focusing only on the comparison of the dose received by the phantom without and with protection in different configurations. The values of CTDI_Vol, DLP and standard deviation from the value without protection are presented in Table 1. Configuration CTDIvol (mGy) Standard Deviation to the value without protection DLP (mGy.cm) Standard Deviation to the value without protection Without protection 2,52 0,0% 5,04 0,0% With protection (no sponge) 1,95 -22,6% 3,90 -22,6% With...

This study verified the reliability of bismuth protection using different configurations and by determining the percentage of dose reduction, image quality and the influence of protection on the gantry in the normal functioning of CT scans. In the configuration with protection but without sponge, there was a dose reduction percentage of 22.6% but the image quality was adversely affected in respect to uniformity and the presence of streak artifact. Although, the configuration with protection with a sponge and two sponges were slightly better than the...

Rui Almeida (MSc), Professor in the Medical Imaging and Radiotherapy Department, Health School - University of Algarve, Portugal. Radiographer in Centro Hospitalar do Algarve, Portugal. Researcher in CICS.NOVA (Universidade Nova de Lisboa – Pólo de Évora) and Member of the Studies Center in Healthcare (CES-ESSUALG). E-mail: [email protected]. Tel: +351289800100 Everaldo Santos (BSc), Collaborator in the Medical Imaging and Radiotherapy Department, Health School - University of Algarve, Portugal. Patrick Sousa (PhD), Professor in the Medical Imaging and Radiotherapy Department, Health School - University of Algarve, Portugal....

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