POSTER SECTIONS Coverpage Purpose Methods and materials Results Conclusion Personal information and conflict of interest References

ECR 2020 / C-05514

Investigation of contrast medium reduction limit using dual energy CT assuming anterior choroidal artery 3D 　-Phantom study-

Congress:

ECR 2020

Poster Number:

C-05514

Type:

Scientific Exhibit

Keywords:

Performed at one institution, Not applicable, Image verification, Aneurysms, Physics, Contrast agent-intravenous, CT-High Resolution, CT-Angiography, CT, Vascular, Head and neck, Contrast agents

Authors:

H. TOMITA¹, Y. Kidokoro²; ¹Kawaguchi Saitama Prefecture/JP, ²Kawaguchi Saitama Prefecture, Saitama/JP

DOI:

10.26044/ecr2020/C-05514

DOI-Link:

https://dx.doi.org/10.26044/ecr2020/C-05514

Fig. 1: Materials

Fig. 2: Vascular phantom

Fig. 3: Vascular phantom We placed the simulated blood vessel phantom in a cylindrical...

Fig. 4: How to measure We scanned a simulated vascular phantom with a contrast agent...

Fig. 5: Parameters Our phantom scan parameters.

Fig. 6: Continuous Confidence Method：VR and MIP images

Fig. 7: Continuous Confidence Method：VR In VR, the distance between 600 HU and 450...

Fig. 8: Continuous Confidence Method： MIP In the MIP, the LSD distance was 0, and...

Fig. 9: SD6 image When SD = 6, there was a significant difference between VR and MIP...

Fig. 10: SD = 8 image When SD = 8, there was a significant difference between the VR...

Fig. 11: Image Quality What are the limits for reducing the contrast agent and exposure...

Purpose

In recent years, Dual Energy CT images have been widely used clinically. 1) Virtual monochromatic energy imaging (VMI) at low energy levels of dual energy CT has been reported to increase iodine CT values and reduce contrast agents. 2) 3) 4) However, various methods for reducing the contrast agent have been reported, but there are few studies on thin blood vessels. Indeed, when targeting small vessels, excessive reduction must be performed with care, as CT values may not increase as expected. In this study, we...

Methods and materials

The CT scanner used IQon Spectral CT (PHILIPS,Netherlands), Vascular phantom is made of acrylic and hole diameter is 0.8, 0.6, 0.5 mm. We used ZIO station 2 (AMIN corporation) for Workstation. We filled the vascular phantom with dilute contrast medium (600, 450, 300, and 150 HU). The phantom was placed at the center of a 21 cm diameter cylindrical phantom filled with water. Then, we scanned the phantom using the parameters that the SDs around the phantom were 4, 6, and 8. (Fig.1,2,3,4) Fig.5 shows...

Results

The VR were poor in branched blood vessels at 150 and 300 HU(P

Conclusion

In clinical applications, it became clear that thin blood vessels of 1 mm or less depends on the contrast medium reduction level and the dose of images, and it suggested the possibility of reduction the contrast medium by 25 % to 50 %.

Personal information and conflict of interest

H. Tomita; Kawaguchi Saitama Prefecture/JP - nothing to disclose Y. Kidokoro; Kawaguchi Saitama Prefecture, SAITAMA/JP - nothing to disclose

References

１）Goo HW “Dual-Energy CT: New Horizon in Medical Imaging.” Korean J Radiol. 2017 Jul-Aug;18(4):555-569. 2) F. Pontana, J. Pagniez, A. Duhamel, T. Flohr, J.B. Faivre, C. Murphy, J. Remy, M. Remy-Jardin, “Reduced-dose low-voltage chest CT angiography with Sinogram-affirmed iterative reconstruction versus standard-dose filtered back projection,” Radiology 267, 609-618 (2013). doi: 10.1148/radiol.12120414. 3) L. Faggioni, E. Neri, P. Sbragia, R. Pascale, L. D'Errico, D. Caramella, C. Bartolozzi, “80-kV pulmonary CT angiography with 40 mL of iodinated contrast material in lean patients: comparison of vascular enhancement with...

Investigation of contrast medium reduction limit using dual energy CT assuming anterior choroidal artery 3D -Phantom study-