Technical Evaluation of a Low Dose Lung Cancer Screening Computed Tomography Protocol using a Beam-Shaping Silver Filter and Deep Learning Reconstruction

Congress:

ECR 2023

Poster Number:

C-15391

Type:

Scientific Exhibit

Keywords:

Artificial Intelligence, Radiation physics, CT, CT-Quantitative, Neural networks, Perception image, Physics, Screening, Cancer, Image verification, Quality assurance

Authors:

K. Boedeker, D. Shin, N. Akino, T. goto, K. Haioun, Y. Hamada

DOI:

10.26044/ecr2023/C-15391

DOI-Link:

https://dx.doi.org/10.26044/ecr2023/C-15391

Purpose

Lung cancer is associated with both high incidence and high mortality, resulting in an estimated 387,913 deaths throughout Europe in 20181. Earlier detection of lung cancer is key to improving survival rates. Low dose Lung Cancer Screening (LCS) with Computed Tomography (CT) has shown success in reducing mortality2-4. A new Silver filter that shifts the energy of the x-ray beam to the higher energies has been developed on a wide volume CT scanner. The Silver filter’s harder beam increases the penetrating power of the beam...

Methods and materials

The baseline Lung Cancer Screening protocol was selected from the American Association of Medical Physicists (AAPM) protocol page for the CT system (Aquilion ONE Prism Edition, Canon Medical Systems, Otawara, Japan)5. This baseline protocol uses the standard x-ray beam filter with conventional HIR. Because the AAPM protocol uses automatic exposure control, the recommended AEC setting was used to establish the fixed tube current used for each phantom evaluation. Low Contrast Detectability (LCD) was examined using the 10HU, 6-15mm test objects in the low contrast detectability...

Results

Low Contrast Detectability The LCD for the Silver filter and DLR was equivalent to that of the baseline LCS protocol using a standard filter with HIR at the same dose (1.2mGy for standard beam filter with HIR/1.1mGy for Silver beam filter with DLR). The d’ at 1.2mGy/1.1mGy ranged from 0.5-2.5, depending on object size. For the other dose levels examined for Silver filter with DLR, LCD performance trended with dose. Results are summarized in Figure 1. [Fig 1] Noise and Noise Texture The noise magnitude...

Conclusion

The beam-shaping Silver filter combined with DLR maintains low contrast detectability and improves CNR relative to a standard x-ray beam filter with HIR for low dose Lung Cancer Screening.

Personal information and conflict of interest

K. Boedeker: Employee: Canon Medical Systems D. Shin: Employee: Canon Medical Systems N. Akino: Employee: Canon Medical Systems t. goto: Employee: Canon Medical Systems K. Haioun: Employee: Canon Medical Systems Y. Hamada: Employee: Canon Medical Systems

References

1 van Meerbeeck JP, Franck C. Lung cancer screening in Europe: where are we in 2021? Transl Lung Cancer Res. 2021 May;10(5):2407-2417. 2 de Koning HJ, van der Aalst CM, de Jong PA, et al. Reduced Lung-Cancer Mortality with Volume CT Screening in a Randomized Trial. New Engl J Med 2020;382:503-13. 3 Becker N, Motsch E, Trotter A, et al. Lung cancer mortality reduction by LDCT screening-Results from the randomized German LUSI trial. Int J Cancer 2020;146:1503-13. 4 Pastorino U, Silva M, Sestini S, et...

Table 1: Low Dose Lung Cancer Screening protocols used for LCD evaluation

Table 2: Low Dose Lung Cancer Screening protocols used for Noise Magnitude and CNR...

Table 3: Low Dose Lung Cancer Screening protocols used for MTF evaluation

Fig 1: Low Contrast Detectability Results, comparing baseline standard beam filter...

Table 4: Noise magnitude results, comparing baseline standard filter with HIR to Silver...

Fig 2: NPS for Body Sharp reconstructions, comparing baseline standard filter with HIR...

Fig 3: NPS for Lung reconstructions, comparing baseline standard filter with HIR to...

Table 5: CNR results, comparing baseline standard filter with HIR to Silver filter with...

Fig 5: High Contrast MTF for Body reconstruction, comparing baseline standard filter...

Fig 6: High Contrast MTF for Lung reconstruction, comparing baseline standard filter...

Fig 7: Low Contrast MTF for Body reconstruction, comparing baseline standard filter...

Fig 8: Low Contrast MTF for Lung reconstruction, comparing baseline standard filter...

Fig 4: Clinical images of low dose Lung Cancer Screening CT scan acquired with a...