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Session: Multi-Disciplinary General ePoster Viewing [Return to Session]

Foreign Bodies Detection in Pediatrics with Low Dose CT

M Aljallad1*, (1) West County Radiology, St. Louis, MO


PO-GePV-M-217 (Sunday, 7/25/2021)   [Eastern Time (GMT-4)]

Purpose: To develop a reasonable image quality CT protocol to detect the foreign bodies (FBs) in the respiratory tract of pediatrics with both a minimum patient radiation dose and an equivalent radiation risk to a conventional radiograph chest exam.

Methods: CT Data were collected on a Siemens CT system (SOMATOM Flash). The imaging techniques of the child CT chest protocol were optimized, and vendor dose optimization features were utilized to further lower the dose and maintain good image quality. Twenty CT exams using the modified CT protocol were performed with different FBs distributions in a five years old size anthropomorphic phantom (LUNGBOY) shown in Figure(1). The FBs included small size radiopaque bodies such as fish bones, peanuts, LEGO toys, etc. The exams were then presented randomly to the radiologist team to interpret the images and report the results. The CT effective and organ doses were calculated by Radimetrics™ software using Monte Carlo (MC) simulations. For dose comparison purposes, we used the routine chest radiograph exam to image the LUNGBOY phantom. The chest radiograph's organ dose is calculated using MC PCXC2.0 software for five years of phantom’s lung, heart, and liver.

Results: The effective dose of the original protocol was 3 mSv, while the dose of the modified protocol was only 0.26 mSv. The reduction in dose by one order of magnitude was mainly caused by the kVp and mAs reduction. The reported effective doses of the LUNGBOY for the modified CT using MC simulations and the chest radiograph using MC PCXC2.0 software and ICRP 103 weighting factors are listed in table(1).

Conclusion: Low-dose CT protocols can be very reliable for FB detection with high image quality and low patient dose, especially in pediatric patients where the aspiration of FBs is a frequent and severe cause of respiratory problems in children.



    CT, Radiation Dosimetry, Image Analysis


    IM- CT: Radiation dosimetry & risk

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