Background/introduction
The lens of the eye and breast are considered among the most radiosensitive tissues of the human body. Increased attention should thus be given to minimize radiation dose to these tissues, especially in children that are considered more radiosensitive than adults and are more likely to undergo multiple CT examinations during their lifetime.
Organ-based tube current modulation (OTCM) techniques reduce the x-ray tube current (mA) over the anterior part of the patient’s body circumference aiming to minimize radiation exposure to superficial radiosensitive organs such as...
Description of activity and work performed
Four physical anthropomorphic phantoms that represent the average individual as neonate, 1-year-old, 5-year-old, and 10-year-old were used. Standard head and thorax acquisitions were performed with automatic tube current modulation (ATCM) and ATCM+OTCM using a 64-detector row CT scanner (Revolution GSI, GE Medical Systems). When OTCM is enabled, the mA is reduced by up to 30% across 900 anterior projections in head and up to 40% across 1800 anterior projections in body examinations (Figure 1).
The angular range of OTCM exposure window was determined for different...
Conclusion and recommendations
The angular range of OTCM exposure window is narrowed at short t. OTCM reduces radiation dose to exposed radiosensitive organs with the eye lens and breast buds exhibiting the highest dose reduction. An increase in noise is however inevitable in images located within the OTCM-activated imaged volume.
Personal/organisational information
J. Damilakis; Heraklion/GR - nothing to disclose A. Papadakis; Heraklion/GR - nothing to disclose
References
Euler A, Szucs-Farkas Z, Falkowski AL, et al (2016) Organ-based tube current modulation in a clinical context: Dose reduction may be largely overestimated in breast tissue. Eur Radiol 26(8):2656-2662
Taylor S, Litmanovich DE, Shahrzad M, Bankier AA, Gevenois PA, Tack D (2015) Organ-based tube current modulation: are women's breasts positioned in the reduced-dose zone? Radiology 274(1):260-266
Papadakis AE, Damilakis J. (2019) Automatic Tube Current Modulation and Tube Voltage Selection in Pediatric Computed Tomography: A Phantom Study on Radiation Dose and Image Quality. Invest Radiol 54(5):265-272...