Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans
This study evaluated the effect of pitch on 256-slice helical computed tomography (CT) scans. Cylindrical water phantoms (CWP) were measured using axial and helical scans with various pitch values. The surface dose distributions of CWP were measured, and reconstructed images were obtained using filt...
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MDPI AG
2023-03-01
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| Online Access: | https://www.mdpi.com/1424-8220/23/7/3472 |
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| author | Kenji Yamada Yoshiki Kawata Masafumi Amano Hidenobu Suzuki Masahide Tominaga Motoharu Sasaki Hikaru Nishiyama Masafumi Harada Noboru Niki |
| author_facet | Kenji Yamada Yoshiki Kawata Masafumi Amano Hidenobu Suzuki Masahide Tominaga Motoharu Sasaki Hikaru Nishiyama Masafumi Harada Noboru Niki |
| author_sort | Kenji Yamada |
| collection | DOAJ |
| description | This study evaluated the effect of pitch on 256-slice helical computed tomography (CT) scans. Cylindrical water phantoms (CWP) were measured using axial and helical scans with various pitch values. The surface dose distributions of CWP were measured, and reconstructed images were obtained using filtered back-projection (FBP) and iterative model reconstruction (IMR). The image noise in each reconstructed image was decomposed into a baseline component and another component that varied along the z-axis. The baseline component of the image noise was highest at the center of the reconstructed image and decreased toward the edges. The normalized 2D power spectra for each pitch were almost identically distributed. Furthermore, the ratios of the 2D power spectra for IMR and FBP at different pitch values were obtained. The magnitudes of the components varying along the z-axis were smallest at the center of the reconstructed image and increased toward the edge. The ratios of the 3D power spectra on the f<sub>x</sub> axis for IMR and FBP at different pitch values were obtained. The results showed that the effect of the pitch was related to the component that varied along the z-axis. Furthermore, the pitch had a smaller effect on IMR than on FBP. |
| first_indexed | 2024-03-11T05:25:06Z |
| format | Article |
| id | doaj.art-b9a7a12d5c7f4de69990a3d31acae83d |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-11T05:25:06Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
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| spelling | doaj.art-b9a7a12d5c7f4de69990a3d31acae83d2023-11-17T17:33:03ZengMDPI AGSensors1424-82202023-03-01237347210.3390/s23073472Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography ScansKenji Yamada0Yoshiki Kawata1Masafumi Amano2Hidenobu Suzuki3Masahide Tominaga4Motoharu Sasaki5Hikaru Nishiyama6Masafumi Harada7Noboru Niki8Division of Clinical Technology, Tokushima University Hospital, Tokushima 7708503, JapanInstitute of Post-LED Photonics, Tokushima University, Tokushima 7708506, JapanDivision of Clinical Technology, Tokushima University Hospital, Tokushima 7708503, JapanInstitute of Post-LED Photonics, Tokushima University, Tokushima 7708506, JapanDepartment of Diagnostic Radiology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima 7708503, JapanDepartment of Therapeutic Radiology, Graduate School of Biomedical Sciences, Tokushima University, Tokushima 7708503, JapanDepartment of Radiological Technology, Ehime University Hospital, Toon 7910295, JapanDepartment of Radiology and Radiation Oncology, Tokushima University, Tokushima 7708503, JapanFaculty of Science and Technology, Tokushima University, Tokushima 7708506, JapanThis study evaluated the effect of pitch on 256-slice helical computed tomography (CT) scans. Cylindrical water phantoms (CWP) were measured using axial and helical scans with various pitch values. The surface dose distributions of CWP were measured, and reconstructed images were obtained using filtered back-projection (FBP) and iterative model reconstruction (IMR). The image noise in each reconstructed image was decomposed into a baseline component and another component that varied along the z-axis. The baseline component of the image noise was highest at the center of the reconstructed image and decreased toward the edges. The normalized 2D power spectra for each pitch were almost identically distributed. Furthermore, the ratios of the 2D power spectra for IMR and FBP at different pitch values were obtained. The magnitudes of the components varying along the z-axis were smallest at the center of the reconstructed image and increased toward the edge. The ratios of the 3D power spectra on the f<sub>x</sub> axis for IMR and FBP at different pitch values were obtained. The results showed that the effect of the pitch was related to the component that varied along the z-axis. Furthermore, the pitch had a smaller effect on IMR than on FBP.https://www.mdpi.com/1424-8220/23/7/3472helical computed tomographypitchsurface dose distributionFBPIMRimage noise |
| spellingShingle | Kenji Yamada Yoshiki Kawata Masafumi Amano Hidenobu Suzuki Masahide Tominaga Motoharu Sasaki Hikaru Nishiyama Masafumi Harada Noboru Niki Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans Sensors helical computed tomography pitch surface dose distribution FBP IMR image noise |
| title | Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans |
| title_full | Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans |
| title_fullStr | Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans |
| title_full_unstemmed | Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans |
| title_short | Influence of Pitch on Surface Dose Distribution and Image Noise of Computed Tomography Scans |
| title_sort | influence of pitch on surface dose distribution and image noise of computed tomography scans |
| topic | helical computed tomography pitch surface dose distribution FBP IMR image noise |
| url | https://www.mdpi.com/1424-8220/23/7/3472 |
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