Background. Radiation using conventional X‐ray is associated with exposure of radiosensitive organs and typically requires the use of protection. This study is aimed at evaluating the use of bismuth shielding for radiation protection in pediatric pelvic radiography. The effects of the anteroposterior and lateral bismuth shielding were verified by direct measurements at the anatomical position of the gonads. Methods. Radiation doses were measured using optically stimulated luminescence dosimeters (OSLD) and CIRS ATOM Dosimetry Verification Phantoms. Gonad radiographs were acquired using different shields of varying material (lead, bismuth) and thickness and were compared with radiographs obtained without shielding to examine the effects on image quality and optimal reduction of radiation dose. All images were evaluated separately by three pediatric orthopedic practitioners. Results. Results showed that conventional lead gonadal shielding reduces radiation doses by 67.45%, whereas dose reduction using one layer of bismuth shielding is 76.38%. The use of two layers of bismuth shielding reduces the dose by 84.01%. Using three and four layers of bismuth shielding reduces dose by 97.33% and 99.34%, respectively. Progressively lower radiation doses can be achieved by increasing the number of bismuth layers. Images obtained using both one and two layers of bismuth shielding provided adequate diagnostic information, but those obtained using three or four layers of bismuth shielding were inadequate for diagnosis. Conclusions. Bismuth shielding reduces radiation dose exposure providing appropriate protection for children undergoing pelvic radiography. The bismuth shielding material is lighter than lead, making pediatric patients more comfortable and less apt to move, thereby avoiding repeat radiography.

Adjuvant radiotherapy is an important treatment modality after breast-conserving surgery. Due to its proximity, radiation therapy for the left breast can often lead to an escalated heart dose that can result in heart diseases. The purpose of this study was to evaluate the heart dose reduction by using lead shields surrounding the left breast. The doses of a 3D conformal radiotherapy (3D-CRT) plan, an intensity-modulated radiotherapy (IMRT) plan, and volumetric-modulated arc therapy (VMAT) to the left breast tumor in a CIRS ATOM anthropomorphic female adult phantom were measured by optically stimulated luminescence dosimeters (OSLDs). To protect critical organs, the skin around the target area was covered by lead shields of two different thicknesses (0.125 mm and 0.25 mm). The results showed that compared to IMRT and 3D-CRT, VMAT provided better planning target volume (PTV) coverage, a better conformity index (CI), and homogeneity index (HI). With the use of lead shields, the thyroid dose was reduced by 5.12–27.5% and 20.51–30%, respectively; the heart dose was reduced by 49.41–50.12% and 56.38–57.42%, respectively; and the lung dose was reduced by 1.23–45.22% and 0.98–57.83%, respectively. Although the clinical application of lead shields was rare, this study verified that it could effectively decrease the heart dose from 4.31 ± 0.09 Gy to 1.88–2.18 Gy, thereby potentially reducing the risk of associated heart diseases by 14.8%. Further works to implement this method into clinical practice are needed.

Industrial radiography is a common nondestructive testing (NDT) method used in various industries. An investigation was conducted for a 1999 incident in Taiwan where two workers (Operators A and B) were accidently exposed to an unshielded Ir source while conducting industrial radiography. Operators A and B experienced acute close-range radiation exposure to a source of Ir for 3 h at a strength of 2.33 × 10 Bq. The health of mammary glands, bone marrow, thyroid glands, eyes, and genital organs of these two workers after radiation exposure was examined. Subsequently, Operator A experienced severe radiation injury, including tissue necrosis and keratinization in the fingers, chromosomal abnormalities, reduced blood cell count, diffuse hyperplasia of the thyroid gland, opaque spots in the crystalline lens, and related radiation effects. The results showed that the left index finger and thumb, eyes, and gonads of Operator A were exposed to a radiation dose of about 369-1,070, 23.1-67.4, 2.4-5.3, and 4.2-11.6 Gy, respectively. Effective dose for Operator A was estimated to range from 6.9 to 18.9 Sv. The left fingers, thumb, eyes, and gonads of Operator B were exposed to a radiation dose of 184.9-646.2, 11.8-40.7, 0.49-3.33, and 0.72-7.18 Gy, respectively, and his effective dose was between 2.5 and 11.5 Sv. This accident indicated a major flaw in the control and regulation of radiation safety for conducting NDT industrial radiography in 1999; however, similar problems still exist. Modifications of the Ionizing Radiation Protection Act in Taiwan are suggested in this study to regulate the management of NDT industries, continually educate the NDT workers in radiation safety, and enact notification provisions for medical care systems toward acute radiation exposure events.

This study aimed to evaluate the effects of fogging on the effectiveness of a lead glass shield in protecting an operator from radiation exposure during conventional coronary angiography (CAG). Optically stimulated luminescence dosimeters (OSLDs) were used to measure the effects of fogged lead glass shields (FLSs) and clear lead glass shields (CLSs) on the radiation doses of a cardiac catheterization surgeon. We simulated the scatter radiation incident on the operator with five angiographic projections with 10-s exposures. Experiments were conducted with a field of view of 25 cm, maximum of 100 cm between the X-ray tube and image intensifier, and 80 cm between the image intensifier and operator. Lead glass fogging had no significant effect at any angiographic projection. The average dose at the lens of the eye, thyroid glands, and gonads did not differ significantly between FLS and CLS. Although most surgeons view ceiling-suspended shields as hindrances during surgical procedures, the radiation dose at the operator’s eyes and thyroid glands increased by 13 and 10 times without the shield. The fogging of the shield is probably caused by post-surgery UV decontamination or detergents. An operator has no cause for concern regarding the radiation protection afforded by an FLS during CAG procedures.

This article compares the effectiveness of both image strength fluctuation (ISF) and statistical parametric mapping (SPM), which is used for analyzing cerebral blood flow traced by single photon emission computed tomography (SPECT) in patients with Alzheimer’s disease (AD). This is a retrospective study that uses the built-in SPECT template of the SPM software to analyze the differences in cerebral blood flow (CBF) between two groups after using the ISF and SPM software to normalize and smooth the data. Using Z score analysis, the ISF method revealed unusual fluctuations in the range of image strength. The hot and cold areas were considered to be the difference between normal and abnormal images and the analysis of the gray intensities of cold and hot areas was used to show that cold and hot were in characteristic locations that correlate with brain functional areas. The results of the SPM analysis revealed significantly reduced blood flow in the bilateral inferior parietal lobule, the middle or superior gyrus of the left temporal lobe, the superior gyrus and the sub-lobar insula of the right temporal lobe. The results from SPM were similar to those obtained with the ISF and indicated the same regions (83.3%).