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Focus DWI 검사에서 중심축 이동에 따른 화질 평가

The Evaluation of Imaging Quality Depending the Shift of the Central Axis in FOCUS DWI Investigation

  • 김용화 (동신대학교 방사선학과) ;
  • 정문택 (동신대학교 방사선학과) ;
  • 최남길 (동신대학교 방사선학과)
  • Kim, Younghwa (Department of Radiological Science, Dongshin University) ;
  • Jeong, Moontaeg (Department of Radiological Science, Dongshin University) ;
  • Choi, Namgil (Department of Radiological Science, Dongshin University)
  • 투고 : 2018.09.20
  • 심사 : 2018.10.31
  • 발행 : 2018.10.31

초록

기존의 자기공명영상검사에서 문제점으로 지적되어 왔던 위상부호화 방향에서의 긴 판독시간과 낮은 대역폭과 함께 기하학적 왜곡의 경향이 있어 이러한 영상왜곡을 감소하기 위한 여러 방법 중 FOCUS-DWI가 있다. 본 논문은 선택적인 위상 방향 및 슬라이스를 이용하는 FOCUS-DWI가 자기장 내 중심축에서 거리변화에 따른 인공물, 균일도를 기존의 Conventional-DWI와 비교하여 그에 대한 유용성을 확인하고자 하였다. 인공물 발생에 대한 결과는 Conventional-DWI 기법에서 불규칙적인 줄무늬 인공물이 발생하였는데 중심축에서 인공물의 발생이 심하게 나타났고, 영상의 겹침 정도가 급격하게 증가하였다. 하지만 FOCUS-DWI 기법은 줄무늬 모양의 인공물 발생이 나타나지 않았고 영상의 겹침 정도도 적게 나타났으며, 영역별 신호측정에 대한 균일도 결과는 중심축에서 거리의 변화에 관계없이 FOCUS-DWI가 훨씬 우수한 기법으로 나타났다. 결론적으로 FOCUS-DWI 기법은 인공물, 영상의 겹침 정도, 균일도 측정에서 Conventional-DWI 기법보다 우수한 결과를 보였고, 거리의 변화에 따른 두 기법에서는 차이가 없게 나타났다. 따라서 FOCUS-DWI 기법은 영상의 왜곡 정도가 적고 화질이 우수하여 임상에서 활용도가 높을 것이라 사료된다.

The problem that the existing the magnetic resonance image (MRI) was prone to have not only long readout duration and low bandwidth in the phase-encode direction, but also geometric distortion was pointed out. The purpose of this study is to identify the usefulness of FOCUS-DWI through comparing FOCUS-DWI with the Conventional-DWI on a degree of uniformity and artifacts caused by the distance change in the central axis within the magnetic field. In terms of artifacts, there happened irregular striped artifacts in the Conventional-DWI technique, which in particular, more often arose in the central axis. Also, the overlap of imaging drastically increased. By contrast, there were no irregular striped artifacts in the FOCUS-DWI technique. In conclusion, it was found that the FOCUS-DWI technique was superior to the Conventional-DWI technique in terms of artifacts, the overlap of imaging, and a degree of uniformity. In addition, there was no difference of the change in distance from the central axis between the FOCUS-DWI technique and the Conventional-DWI technique. Thus, it is considered the FOCUS-DWI technique having less imaging distortion and high image quality will be highly clinically used.

키워드

참고문헌

  1. H. J. YOO, Y. B. Cho, H. I. Kwon, "A Study to evaluate image distortion by position of X-axis in diffusion-weighted MRI(DWI)," Journal of the Korean Society of MR Technology, Vol. 25, No. 1, pp. 97-108, 2015.
  2. Roland Bammer, Franz Fazekas, "Diffusion Imaging of the Human Spinal Cord and Vetebral Column," Topics in Magnetic Resonance Imaging, Vol. 14, No. 6, pp. 461-476, 2003. https://doi.org/10.1097/00002142-200312000-00004
  3. J. B. Andre, G. Zaharchuk, E. Saritas, S. Komakula, A. Shankaranarayan, S. Banerjee, J. Rosenberg, D. G. Nishimura, N. J. Fischbein, "Clinical Evaluation of Reduced Field-of-View Diffusion-Weighted Imaging of the Cervical and Thoracic Spine and Spinal Cord," Am J Neuroradiol, Vol. 33, No. 10, pp. 1860-1866, 2012. https://doi.org/10.3174/ajnr.A3134
  4. S. da Pozzo, R. Manara, S. Tonello, C. Carollo, "Conventional and diffusion-weighted MRI in progressive multifocal leukoencephalopathy: new elements for identification and follow-up," Radial med. Vol. 111, No. 7, pp. 971-977, 2006. https://doi.org/10.1007/s11547-006-0095-3
  5. Emine Ulke Saritas, Charles H. Cunningham, Jin Hyeong Lee, Eric T. Han, Dwight G. Nishimura, "DWI of the Spinal Cord with Reduced FOV Single-Shot EPI," Magnetic Resonance in Medicine, Vol. 60, pp. 468-473, 2008. https://doi.org/10.1002/mrm.21640
  6. Warndahl BA, Borisch EA, Kawaschima A, Reiderer SJ, Froemming AT, "Conventional vs. reduced field of view diffusion weighted imaging of the prostate: Comparison of image quality, correlation with histology, and inter-reader agreement," Magnetic Resonance Imaging, Vol. 47, pp. 67-76, 2018. https://doi.org/10.1016/j.mri.2017.10.011
  7. Zhaoyan Feng, Xiangde Min, Vivek Kumar Sah, Liang Li, Jie Cai, Ming Deng, Liang Wang, "Comparison of field-of-view (FOV) Optimized and Constrained undistorted single shot (FOCUS) with Conventional DWI for the evaluation of prostate cancer," Clinical Imaging, Vol. 39, No. 5, pp. 851-855, 2015. https://doi.org/10.1016/j.clinimag.2015.03.004
  8. M. Wang, H. Liu, X. Wei, C. Liu, T. Liang, X. Zhang, C. Jin, X. Li, Q. Sun, H. Jiang, J. Yang, "Application of Reduced-FOV Diffusion-Weighted Imaging in Evaluation of Normal Pituitary Glands and Pituitary Macroadenomas," American Journal of Neuroradiology, Vol. 39, No. 8, pp. 1499-1504, 2018. https://doi.org/10.3174/ajnr.A5735
  9. G. Zaharchuk, E.U. Saritas, J.B. Andre, C.T. Chin, J. Rosenberg, T.J. Brosnan, A. Shankaranarayan, D.G. Nishimura, N.J. Fischbe, "Reduced Field-of-View Diffusion Imaging of the Human Spinal Cord: Comparison with Conventional Single-Shot Echo-Planar Imaging," Am J Neuroradiol, Vol. 32, No. 5, pp. 813-820, 2011. https://doi.org/10.3174/ajnr.A2418
  10. Mayumi Takeuchi, "Imaging the Female Pelvis with FOCUS DWI and MR Spectroscopy," GEHEALTHCARE.COM/MR, pp. 56-59, 2015.