99mTc을 이용하는 검사를 받고 CT 검사를 진행했을 때 CT 영상에 99mTc이 미치는 변화에 대하여 정량적으로 알아보고자 하였다. Resolution phantom과 Water phantom에 99mTc 740 MBq를 주입 전· 후 80 kVp와 120 kVp로 관전압을 변화시켜 CT Scan하였다. 연구결과 99mTc 주입 전·후 신호강도는 각각 0.173, 0.241의 감소 하였으며, 공간분해능은 각각 0.090, 0.109로 증가하였다. CT 촬영을 99mTc의 유효 반감기를 고려하여 99mTc 의 감마선이 CT에 영향을 미치지 않도록 일정한 시간 후 진행함으로 영상의 변화를 줄일 수 있을 것으로 사료된다.

This study examines the changes that 99mTc causes to CT(Computed Tomography) images quantitatively when CT scans were continuously performed using 99mTc. With the use of the CT, 99mTc 740MBq was injected into the Resolution Phantom and Water Phantom, and the tube voltage was changed with 80 kVp and 120 kVp, scanning before and after the injection. The result indicate, by comparing the Signal Intensity according to the presence or absence of the 99mTc injection with the tube voltage of 120 kVp and 80 kVp, a decrease of 0.173 and 0.241 was observed respectively and the spatial resolution increase of 0.090 and 0.109 was observed respectively. The order of the test should be considered because the gamma rays of the radiopharmaceutical used in the nuclear medicine test do not affect the CT while the effective half-life of the radiopharmaceuticals should be considered for the CT scan to reduce the influence of the gamma rays emitted after the nuclear medicine test, with the possibility to reduce the difference of the results.

ABSTRACT
 Ⅰ. INTRODUCTION
 Ⅱ. MATERIAL AND METHODS
  1. 연구 장비
  2. 연구 방법
  3. 통계 분석
 Ⅲ. RESULT
  1. 정규성 검정
  2. 신호강도(Signal Intensity)
 Ⅵ. DISCUSSION
 Ⅴ. CONCLUSIONS
 Reference

• Jae-Yoon Park(인천기독병원 영상의학과) | 박재윤
• Yong-Ki Lee(동남보건대학교 방사선과) | 이용기 Corresponding Author