손목관절 CT 검사 시 자세 변화와 채널 변경에 따른 MTF평가
MTF Evaluation according to change in posture and channel during CT examination for wrist Joint : X-axis and Z-axis changes around Isocenter
- 한국방사선학회
- 한국방사선학회 논문지
- 제14권 제6호
- : KCI등재
- 2020.11
- 811 - 817 (7 pages)
본 연구의 목적은 손목관절 CT 검사에서 환자 자세를 X-축, Y-축으로 변화시키고 CT 검사장치의 channel 변화에 따른 MTF 평가를 하는 것이다. CT 장치와 손목 팬텀을 이용하여 isocenter를 중심으로 X-축으로 0(일치), 5, 10, 15 cm 이동시켜 검사하고, Z-축은 반시계 방향으로 -20°, -40° 회전하여 검사하였다. 검사는 16, -40, 64 channel을 이용하여 channel 별 차이가 있는지도 확인하고자 하였다. 검사한 영상은 자뼈와 좌우측 노뼈의 MTF 값을 측정하여 비교하였다. isocenter를 중심으로 X-축으로 이동시킨 실험에서 이동 거리가 커질수록 MTF 값은 감소하였고, 이때 MTF 값은 channel과는 무관한 것으로 확인되었다. Z-축에서 반시계 방향으로 -20°, -40° 손목관절을 회전시킨 실험에서 회전정도와 MTF는 무관한 것으로 확인되었다. 또한 channel과도 무관하였다. 결론적으로 손목관절 CT 검사에서 손목은 X-축 방향으로 이동을 최대한 억제시키고, Z-축으로의 회전은 검사 대상자의 환경에 따라 변화하여도 영상의 MTF에는 큰 영향을 주지 않을 것이라 사료된다.
This study aims to evaluate the Modulation Transfer Function (MTF) according to the change in the number of channels of the CT examination device by changing the posture of the patient to the X-axis and Y-axis in the wrist joint CT examination. Using a CT device and a wrist phantom, the test was performed by moving 0 (matched), 5, 10, and 15 cm in the X-axis around the isocenter, and the Z-axis was rotated by -20° and -40° . For the test, 16, -40 and 64 channels were used to check whether there was a difference for each number of channels. The examined images were compared by measuring the MTF values of the ulna and left and right sides of the radius. In the experiment where the isocenter was moved along the X-axis, the MTF value decreased with an increase in the moving distance, and the MTF value was found to be unaffected by the number of channels. In the experiment in which the wrist joint was rotated by -20° and -40° on the Z-axis, the degree of deviation and MTF were found to be irrelevant. It was not related to the number of channels either. In conclusion, the movement of the wrist along the X-axis should be restrained as much as possible for a wrist joint CT scan, whereas deviation around the Z-axis depending on the environment for the patient would not affect the MTF of the image.
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
Ⅲ. RESULT
Ⅳ. DISCUSSION
Ⅴ. CONCLUSION
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