Energy-resolved Computed Tomography エネルギー分解CT

X線を従来通り電流として測定し，入射X線のエネルギー分布を与える

　X線の透過撮影において，一つ一つのX線のエネルギー測定を行うと，ヨウ素造影剤に敏感，ビームハードニング効果(1)が効かないという利点があります．しかし，一つ一つのX線のエネルギーを測定するには，かなりの長時間が必要です．とても，人間のCT撮影にはエネルギー測定法は利用できません．そこで，現在のCT測定のように，X線を電流として測定しつつ，入射X線のエネルギー分布が分かる検出器，transXend検出器を考案しました．

(1)ビームハードニング効果とは，通常の大きさの人間とコニシキのような大きな人の中にある癌とは，見え方が違ってくる，コニシキの身体の中にある癌は発見しにくい，ということです．

エネルギー分解CT

　検出器が3式のtransXend検出器を用いても，1 keVごとの詳細なX線エネルギースペクトルを得ることができます．これにより，透過物質の線減弱係数も1 keVごとに評価でき，透過物質の実効原子番号を評価することができます．人体内部組織の識別に有効であるほか，果物の糖度測定を非破壊で行うことができます．また，尿路結石のタイプを弁別できます．

　人体のように大きな被検体の場合には，X線検出器には直接X線の他に散乱X線も入射し，画質を劣化させます．この散乱X線補正法の開発も行いました．

40. Y. Yamashita, T. Hamaguchi and I. Kanno, "Low-dose energy-resolved X-ray computed tomography using a filter-changing two-dimensional transXend detector", J. Nucl. Sci. Technol., 62, 33-42 (2025).

39. H. Kuniwake, J. Nishikawa, I. Kanno, K. Shimomura, "A scattered X-ray correction method for transmission measurements and its verification using energy-resolved computed tomography", J. Nucl. Sci. Technol., doi-10.1080/00223131.2022.2113164.

38. I. Kanno, D. Ito, "Iodine tomographic images derived from a small number of X-ray transmission measurements using material thickness distributions", J. Nucl. Sci. Technol., doi=10.1080/00223131.2022.207.

37. H. Kuniwake, J. Nishikawa, I. Kanno, K. Shimomura, "Correction of X-ray scattering in energy-resolved computed tomography imaging of 20-cm-diameter phantom", J. Nucl. Sci. Technol., 59, 510-517 (2022).

36. I. Kanno, K. Yamada, "Energy-resolved computed tomography with a response-function-less transXend detector", J. Nucl. Sci. Technol., 58, 1351-1358 (2021).

35. I. Kanno, T. Kuroyama, "Estimation of the sugar content of fruit by energy-resolved computed tomography using a material decomposition method", J. Nucl. Sci. Technol., 58, 533-541 (2021).

34. T. Hamaguchi, I. Kanno, "Effective atomic number estimation by energy-resolved X-ray computed tomography with a current-mode detector system", Jpn. J. Appl. Phys., 58, 071001-6 (2019).

33. S. Toshiro, I. Kanno, "Simplified computed tomography by two-direction transmission imaging using a flat-type "transXend" detector", JPS Conf. Proc. 24, 011028-1-6 (2019).

32. K. Ouchi, I. Kanno, "Metal artifact reduction by energy-resolved CT using two-dimensional "transXend" detector, JPS Conf. Proc. 24, 011027-1-6 (2019).

31. T.-H. Tsai, T. Hamaguchi, H. Iramina, M. Nakamura, I. Kanno, "Filter-based energy-resolved X-ray computed tomography with a clinical imager", J. Nucl. Sci. Technol., 56, 210-220 (2019).

30. H. Iramina, T. Hamaguchi, M. Nakamura, T. Mizowaki, I. Kanno, "Metal artifact reduction by filter-based dual-energy cone beam computed tomography on a bench top micro-CBCT system: concept and demonstration", J. Rad. Res., doi:10.1093/jrr/rry034. (2018) .

29. T.-H. Tsai, T. Hamaguchi, I. Kanno, "Performance improvement of the filter-type "transXend" detector energy-resolving detector by considering noise sensitivity", J. Nucl. Sci. Technol., 55, 663-671 (2018).

28. H. Iramina, M. Nakamura, T. Mizowaki, I. Kanno, "Effective atomic number measurement with energy-resolved computed tomography using two-dimensional "transXend"detector", Int. J. Med. Phys. Clinical Eng. Rad. Oncology, 7, 61-73 (2018).

27. Y. Maruyama, T. Hamaguchi, T.-H. Tsai, I. Kanno, "Response function estimation with fine energy bins for the energy-resolved computed tomography using a transXend detector", J. Nucl. Sci. Technol., 55, 199-208 (2018).

26. T.-H. Tsai, I. Kanno, "A simulation study on the influence of scattered X-rays in energy-resolved computed tomography", J. Nucl. Sci. Technol., 54, 205-212 (2017).

25. I. Kanno, K. Yamauchi, T. Hamaguchi, "Two-dimensional "transXend" detector with band structure absorbers for third-generation energy-resolved computed tomography with improved spatial resolution", J. Nucl. Sci. Technol., 54, 22-29 (2017).

24. H. Iramina, M. Nakamura, Y. Iizuka, T. Mitsuyoshi, Y. Matsuo, T. Mizowaki, M. Hiraoka, I. Kanno, "The accuracy of extracted target motion trajectories in four-dimensional cone-beam computed tomography for lung cancer patients", Radiotherapy and Oncology, 121, 46-51 (2016).

23. T. Hamaguchi, I. Kanno, K. Hotta, M. Nakamura, R. Adachi, "A Current Mode Energy-resolved CT using Several Kinds of Scintillators", JPS Conf. Proc. 11, 060005 (2016).

22. I. Kanno, "A “transXend” Detector for Practical Third Generation Computed Tomography", JPS Conf. Proc. 11, 060001 (2016).

21. I. Kanno, Y. Yamashita, E. Kanai, T. Ogawa, K. Shinsho, "Two-dimensional "transXend" detector for third-generation energy-resolved computed tomography", J. Nucl. Sci. Technol., 53, 258-262 (2016).

20. I. Kanno, Y. Yamashita, M. Kimura, F. Inoue, "Effective atomic number measurement with energy-resolved X-ray computed tomography", Nucl. Instrum. Method A787, 121-124 (2015).

19. Y. Yamashita, M. Kimura, M. Kitahara,T. Hamaguchi, I. Kanno, M. Ohtaka,M. Hashimoto, K. Ara, H. Onabe, "Measurement of Effective Atomic Numbers using Energy- resolved Computed Tomography", J. Nucl. Sci. Technol., 51, 1256-1263 (2014).

18. I. Kanno, R. Imamura, Y. Yamashita, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Using Energy-resolved X-ray Computed Tomography with a Current Mode Detector to Distinguish Materials", Jpn. J. Appl. Phys. , 53, 056601 (2014).

17. Y. Yamashita, K. Shima, I. Kanno, M. Ohtaka, M. Hashimoto, K. Ara, H. Onabe, "Low-dose Exposure Energy-Resolved X-ray Computed Tomography using a Contrast Agent with a High-energy K-edge", J. Nucl. Sci. Technol., 51, 91-97 (2014).

16. I. Kanno, K. Shima, H. Shimazaki, Y. Yamashita, K. Watanabe, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Computed Tomography Reconstruction from Two Transmission Measurements for Iodine-marked Cancer Detection", J. Nucl. Sci. Technol., 50, 1020-1033 (2013).

15. Y. Yamashita, H. Shimazaki, K. Shima, I. Kanno, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Energy- resolved Computed Tomography Measurements of Iron Solution and Adipose as a Simulation for Estimating the Iron Concentration in the Human Liver", J. Nucl. Sci. Technol., 50, 376-380 (2013).

14. I. Kanno, "A transXend detector- principle and Applications", Prog. in Nucl. Sci. and Technol., 3, 1 (2012).

13. I. Kanno, H. Shimazaki, R. Imamura, Y. Yamashita, K. Shima, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Low Dose Exposure Diagnosis with a transXend Detector Aiming for Iodine-marked Cancer Detection", J. Nucl. Sci. and Technol., 49, 937-946 (2012).

12. I. Kanno, R. Imamura, Y. Minami, M. Ohtaka, M. Hashimoto, K. Ara, H. Onabe, "Third-generation Computed Tomography with Energy Information of X-rays using a CdTe Flat Panel Detector", Nucl. Instrum. Meth. in Phys. Res. A695, 268-271 (2012).

11. I. Kanno, Y. Minami, R. Imamura, H. Shimazaki, K. Fukuda, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Advantages of Resopnse Function Change in a transXend Detector with Various Scintillators as Substrates of Segment Detectors", J. Nucl. Sci. and Technol., 48, 1377-1384 (2011).

10. Y. Minami, R. Imamura, I. Kanno, M. Ohtaka, M. Hashimoto, K. Ara, H. Onabe, "Using X-ray Energy Information in CT Measurement of a Phantom with an Al Region", J. Nucl. Sci. and Technol., 48, 108-112 (2011).

9. R. Imamura, K. Mikami, Y. Minami, I. Kanno, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Unfolding Method with X-ray Path Length-dependent Response Functions for Computed Tomography Using X-ray Energy Information", J. Nucl. Sci. and Technol., 47, 1075-1082 (2010).

8. I. Kanno, R. Imamura, K. Mikami, M. Ohtaka, M. Hashimoto, K. Ara and H. Onabe, "Computed Tomography for Iodine Contrast Media Detection using Energy Information Measured by a Current-mode Detector", Nucl. Instrum. and Method in Phys. Res., A624, 219-222 (2010).

7. I. Kanno, R. Imamura, K. Mikami, M. Hashimoto, M. Ohtaka, K. Ara, S. Nomiya, H. Onabe, "Energy Subtraction Computed Tomography Measured by Current-mode Detector", Nucl. Instrum. and Method., A610, 325-327 (2009).

6. M. Hashimoto, M. Ohtaka, K. Ara, I. Kanno, R. Imamura, K. Mikami, S. Nomiya and H. Onabe, "Simulation Study on the Unfolding Methods for Diagnostic X-rays and Mixed Gamma Rays", J. Nucl. Sci. and Technol., 46, 76-82 (2009).

5. I. Kanno, R. Imamura, K. Mikami, A. Uesaka, M. Hashimoto, M. Ohtaka, K. Ara, S. Nomiya, and H. Onabe, "A Current Mode Detector for Unfolding X-ray Energy Distribution", J. Nucl. Sci. and Technol., 45, 1165-1170 (2008).

4. I. Kanno, A. Uesaka, S. Nomiya and H. Onabe, "Energy Measurement of X-rays in Computed Tomography for Detecting Contrast Media", J. Nucl. Sci. and Technol., 45, 15-24 (2008).

3. I. Kanno, A. Uesaka, S. Nomiya and H. Onabe, "Comparison of Current and Energy X-ray Measurement Methods in Contrast Media Detection", Nucl. Instrum. and Meth. in Phys. Res. A 580, 534-536 (2007).

2. I. Kanno, M. Takahashi, H. Aoki, and H. Onabe, "Energy Subtraction Method with Filtered X-rays for the Detection of Contrast Media", Nucl. Instrum. and Meth. in Phys. Res. A567, 154-157 (2006).

1. I Kanno, S. Maetaki, H. Aoki, S. Nomiya and H. Onabe, "Low Exposure X-ray Transmission Measurements for Contrast Media Detection with Filtered X-rays", J. Nucl. Sci. Technol., 40, 457-463 (2003).