Evaluation of Eye Lens Dose Reduction Technics in Head CT

The purpose of this study is to find the best protocol to reduce the X-ray dose to the eye lens during head diagnostic computed tomography (CT) without decreasing image quality in the organs of interest according to the type of scanner. The lens of the eye is one of radiosensitive tissues in the body. Radiation induced cataract has been demonstrated among staff involved in interventional procedures using X-rays. This study compares the absorbed dose and image quality of several dose reduction technics to the eye lens during head CT exam namely bismuth shielding, organ-based dose modulation, tube current modulation, tube voltage modulation and the combination of a number of these techniques. Compared to the reference scan (Fixed tube current without bismuth shielding), the dose to the eye lens was reduced by 29.91% with bismuth shield, 14.55% with tube current modulation, 37.76% with tube current modulation and bismuth shield. The combination of organ-based dose modulation with tube voltage modulation reduced the dose by 44.93% that of tube current modulation with tube voltage modulation reduced by 19.03% and that of tube current modulation with tube voltage modulation and shield by 46.73%. The combination of organ-based dose with tube voltage modulation provided superior image quality than that of tube current modulation with tube voltage modulation and shield while similarly reducing dose to the eye lens.

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Radiation dose reduction to the eye lens in head CT using tungsten functional paper and organ-based tube current modulation

European Journal of Radiology ◽

10.1016/j.ejrad.2020.108814 ◽

2020 ◽

Vol 124 ◽

pp. 108814

Author(s):

Hiroyuki Kosaka ◽

Hajime Monzen ◽

Morikazu Amano ◽

Mikoto Tamura ◽

Shota Hattori ◽

...

Keyword(s):

Radiation Dose ◽

Dose Reduction ◽

Radiation Dose Reduction ◽

Eye Lens ◽

Tube Current Modulation ◽

Current Modulation ◽

Head Ct ◽

Tube Current ◽

Functional Paper

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MO-F-CAMPUS-I-04: Patient Eye-Lens Dose Reduction in Routine Brain CT Examinations Using Organ-Based Tube Current Modulation and In-Plane Bismuth Shielding

Medical Physics ◽

10.1118/1.4925489 ◽

2015 ◽

Vol 42 (6Part30) ◽

pp. 3584-3584

Author(s):

Hui-Yu Tsai ◽

Ying-Lan Liao ◽

Nan-Ku Lai ◽

Jun-Rong Chen ◽

Tou-Rong Chen

Keyword(s):

Dose Reduction ◽

Eye Lens ◽

Tube Current Modulation ◽

Current Modulation ◽

Brain Ct ◽

Eye Lens Dose ◽

Tube Current ◽

Bismuth Shielding

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COMPARISON OF ORGAN-BASED TUBE CURRENT MODULATION AND BISMUTH SHIELDING IN CHEST CT: EFFECT ON THE IMAGE QUALITY AND THE PATIENT DOSE

Radiation Protection Dosimetry ◽

10.1093/rpd/ncy242 ◽

2018 ◽

Vol 185 (1) ◽

pp. 42-48

Author(s):

Antti Kotiaho ◽

Anna-Leena Manninen ◽

Juha Nikkinen ◽

Miika Tapio Nieminen

Keyword(s):

Image Quality ◽

Dose Reduction ◽

Absorbed Dose ◽

Chest Ct ◽

Tube Current Modulation ◽

Current Modulation ◽

Absorbed Doses ◽

Tube Current ◽

Bismuth Shielding

Abstract The aim of the study was to compare the absorbed doses and image quality of organ-based tube current modulation (OBTCM) and bismuth shielding of breasts and thyroid against regular tube current modulation in chest CT scan. An anthropomorphic phantom and MOSFET dosemeters were used to evaluate absorbed doses. Image quality was assessed from HU and noise. Relative to the reference scan, the average absorbed dose reduction with OBTCM was 5.2% and with bismuth shields 24.2%. Difference in HU values compared to the reference varied between −4.1 and 4.2 HU in OBTCM scan and between −22.2 and 118.6 HU with bismuth shields. Image noise levels varied between 10.0 to 26.3 HU in the reference scan, from 9.6 to 27.7 HU for the OBTCM scan and from 11.9 to 43.9 HU in the bismuth scan. The use of bismuth shields provided greatest dose reduction compared to the investigated OBTCM.

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