Touko Kaasalainen, Presenter: Nothing to Disclose

Kirsi Palmu MSc, Abstract Co-Author: Nothing to Disclose

Anniina Lampinen, Abstract Co-Author: Nothing to Disclose

Vappu Reijonen PhD, Abstract Co-Author: Nothing to Disclose

Junnu Leikola, Abstract Co-Author: Nothing to Disclose

Riku Kivisaari, Abstract Co-Author: Nothing to Disclose

Mika Karel Kortesniemi PhD, Abstract Co-Author: Nothing to Disclose

To evaluate the possibility of using ultralow-dose CT protocols with model-based iterative reconstruction technique for craniosynostosis imaging.

Two anthropomorphic phantoms, corresponding pediatric newborn and 5-year-old patients, were scanned with 64-slice CT scanner using different low-dose protocols. Organ doses in the head region were measured with MOSFET dosimeters, and doses of low-dose scans were compared to routine protocols of hospital for craniosynostosis. Additionally, organ doses, as well as effective doses, were also determined by simulations. Image quality was evaluated objectively and subjectively using ASIR30%, ASIR50% and VEO reconstructed images. Image noise and contrast were determined from the CT number histograms of different tissues. Subjective image quality was evaluated in a blinded manner using a Likert scale by two experienced physicians.

In the newborn phantom, mean organ dose was reduced up to 83% compared to routine protocol when using ultralow-dose scanning settings (80 kVp and fixed 10 mA tube-current). Similarly, in the 5-year-old phantom, the greatest radiation dose reduction was up to 88% compared to our routine protocol. The simulations supported the findings with MOSFET measurements. According to objective and subjective image quality analysis, the image quality remained adequate with VEO reconstruction even with the lowest dose level.

Craniosynostosis CT with VEO could be performed in our study by approximately 20 μSv effective dose for the patient, corresponding to the radiation exposure of plain skull radiography, without compromising adequate image quality.

Radiation doses of craniosynostosis patients, who are exposed to repeated CT scans, can be reduced significantly using model-based iterative reconstruction without compromising adequate image quality for diagnosis and treatment.

Kaasalainen, T, Palmu, K, Lampinen, A, Reijonen, V, Leikola, J, Kivisaari, R, Kortesniemi, M, Optimization of Pediatric Craniosynostosis CT with Model-based Iterative Reconstruction (VEO): Phantom Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007800.html