Reduced Radiation Exposure of the Female Breast During Low-Dose Chest CT Using Organ-Based Tube Current Modulation and a Bismuth Shield: Comparison of Image Quality and Radiation Dose

Kim, Yoon Kyung; Sung, Yon Mi; Choi, Jin Ho; Kim, Eun Young; Kim, Hyung Sik

doi:10.2214/ajr.12.9237

Cited by 41 publications

(43 citation statements)

References 16 publications

(27 reference statements)

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“…Generally, the bismuth shield application would lead to a beam hardening effect and starvation of information-carrying photons, resulting in an incorrect CT number being calculated during acquisition (Lee et al, 2011;Kim et al, 2013). The mean of the CT number and the SD of the CT numbers collected from the Setup A (no bismuth shield or bolus applied) can thus be used as the reference value of the CT number and image noise level in the present study.…”

Section: Resultsmentioning

confidence: 98%

Reducing the radiation dose to the eye lens region during CT brain examination: the potential beneficial effect of the combined use of bolus and a bismuth shield

et al. 2015

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-Objective:Computed Tomography (CT) is the leading contributor to medical exposure to ionizing radiation. Although the use of CT brain scans for patients with head injuries and convulsions has shown a tremendous growth, it has raised substantial concerns in the general public because of the risk of radiation-induced cataracts: the current available strategies to reduce the radiation dose to the eye lens region are limited. Therefore, the present research project was initiated with the aim of evaluating the potential benefit of the combined use of bolus and a bismuth shield on reducing the radiation dose to the eye lens region during CT brain examination. Materials and methods: We conducted a series of phantom studies to measure the entrance surface dose (ESD) that is delivered to the eye lens region during CT brain examination under the effect of different scanning and shielding setups. Results: Our results indicated, during CT brain examination: (1) a drastic reduction of 92.5% in the ESD to the eye lens region was found when the CT gantry was tilted from 0• (overall ESD = 30.7 mGy) to 30• cranially (overall ESD = 2.4 mGy), and (2) when the CT gantry was positioned at 0• (the common practice in the clinical setting), the setups with the application of a) a bismuth shield, b) a bismuth shield with a face shield (air gap), c) a bismuth shield with bolus, and d) a bismuth shield with bolus and an air gap can result in an acceptable level of image quality with a smaller overall ESD delivered to the eye lens region (overall ESD = 23.2 mGy, 24 mGy, 21 mGy and 19.9 mGy, respectively) than the setup without the bismuth shield applied (overall ESD = 30.7 mGy). Conclusion: When the primary beam scanning through the eye lens region is unavoidable during CT brain examination, the combined use of a bismuth shield with bolus and a face shield is an easyto-use and inexpensive shielding setup to reduce the radiation dose delivered to the eye lens region while maintaining the correct CT number and a low degree of image noise in the resultant image.

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Section: Resultsmentioning

confidence: 98%

Reducing the radiation dose to the eye lens region during CT brain examination: the potential beneficial effect of the combined use of bolus and a bismuth shield

et al. 2015

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“…3 One study by Nikupaavo et al 6 used OBTCM on phantoms to reduce dose to the lens during head CT and reported 32% dose reductions. Similarly, Kim et al 34 reported dose reductions of 20.8% to the superficial breast tissue and 18.8% to the deep portion of the breasts, using OBTCM on female patients undergoing routine chest CT examinations.…”

Section: Organ-based Tube Current Modulationmentioning

confidence: 87%

“…5,19,33 Secondly, the breast is often incidentally exposed to large doses of radiation during CT procedures, even though they are rarely the area of interest. 34,35 Although routine chest CT scanning contributes to the majority of breast irradiation, numerous examinations are of concern. For example, CT pulmonary angiography can result in a mean glandular dose between 20-60 mGy, where as the inferior aspect of the breast can receive 10-20 mGy during abdominal CT. 5 Therefore because of the breasts overall projected radiosensitivity and high incidence of irradiation, reliable and practical dose reduction techniques must be routinely implemented.…”

Section: Breast Dose Reductionmentioning

confidence: 99%

“…These studies suggest dose savings ranging from 20 to 60%, depending on patient type, scanner, shield design and protocol used. 34 …”

Section: Breast Dose Reductionmentioning

confidence: 99%

“…Kim et al 34 raised concerns relating to the influence of patient anatomy, stating that in patients with larger breasts a portion of the breast tissue may fall within the lateral scan region, where an increased tube current would result in an increased amount of dose to the breast. Furthermore, if the patient is positioned off-center than radiosensitive organs could potentially receive more dose from the increased tube current portion of the rotation.…”

Section: Organ-based Tube Current Modulationmentioning

confidence: 99%

See 2 more Smart Citations

The Current Use and Effectiveness of Bismuth Shielding in Computed Tomography: A Systematic Review

Lawrence¹,

Seeram²

2017

Radiol Open J

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CitationThe increased use of computed tomography (CT) has raised concerns regarding the radiation dose received by radiosensitive organs. It is important that practical and reliable dose reduction strategies are implemented to reduce patient radiation exposure. Aims: The purpose of this article is to evaluate the current clinical use and effectiveness of bismuth shielding as a dose reduction technique and assess its impact on image quality, in an attempt to develop a recommendation for dose reduction in CT. Methods: A systematic review of current literature was conducted using the PubMed and Scopus databases. A total of 50 relevant articles were thoroughly assessed and evaluated.Results: This review found that whilst bismuth shielding proves to provide significant dose reductions to radiosensitive organs, numerous concerns exist including wasted radiation, reduced image quality and unpredictable results when combined with AEC. Alternative methods such as tube current modulation and iterative reconstruction algorithms can provide equivalent dose savings at superior image quality, without the limitations of bismuth shields. Conclusion: Until these alternative methods become available in all departments, bismuth shielding remains a viable dose reduction strategy.

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Approach to CT Dose Optimization: Role of Registries and Benchmarking

Kalra

2017

Quality and Safety in Imaging

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Reduced Radiation Exposure of the Female Breast During Low-Dose Chest CT Using Organ-Based Tube Current Modulation and a Bismuth Shield: Comparison of Image Quality and Radiation Dose

Cited by 41 publications

References 16 publications

Reducing the radiation dose to the eye lens region during CT brain examination: the potential beneficial effect of the combined use of bolus and a bismuth shield

Reducing the radiation dose to the eye lens region during CT brain examination: the potential beneficial effect of the combined use of bolus and a bismuth shield

The Current Use and Effectiveness of Bismuth Shielding in Computed Tomography: A Systematic Review

Approach to CT Dose Optimization: Role of Registries and Benchmarking

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