CAJ | 학술논문

目的：评价使用迭代重建技术在双源 CT 检查骶髂关节成像中对图像质量和辐射剂量的影响。方法60例因下腰部不适行双源 CT 骶髂关节检查的患者，随机分为两组：A 组30例，参考管电流为60mAs ，图像重建使用 SAFIRE法；B 组为对照组，也为30例，参考管电流为150mAs ，图像重建使用常规 FBP 法。两组客观图像质量测量均选择在同一层面，分别于骨关节面下松质骨内、邻近肌肉和脂肪内选择感兴趣区（面积为100mm2），测量 CT 值、平均标准差（SD）作为噪声值，记录剂量长度乘积（dose‐length product ，DLP）。采用 Likert 5分评价主观图像质量，并通过 Kappa 方法评价观察者间的一致性。结果两组在各相同松质骨内（218．00±64．57）HU vs （219．23±54．27）HU （ P ＝0．936）、邻近肌肉内（55．67±7．45）HU vs （53．73±4．66）HU （ P ＝0．233）、脂肪内（‐97．67±10．60）HU vs （‐95．30±14．62）HU （ P ＝0．476），CT 值差异均无统计学意义；图像噪声和主观图像质量评分差异也无统计学意义。两组 DLP 分别为（27.20±5.51）mSv vs（78．37±18．51）mSv ，A 组较 B 组分别降低了65．3％（ P ＜0．001），差异有统计学意义。结论当使用低mAs（60mAs）联合迭代重建算法进行骶髂关节 CT 成像时，在保持图像质量的同时，还能极大降低有效辐射剂量。
목적：평개사용질대중건기술재쌍원 CT 검사저가관절성상중대도상질량화복사제량적영향。방법60례인하요부불괄행쌍원 CT 저가관절검사적환자，수궤분위량조：A 조30례，삼고관전류위60mAs ，도상중건사용 SAFIRE법；B 조위대조조，야위30례，삼고관전류위150mAs ，도상중건사용상규 FBP 법。량조객관도상질량측량균선택재동일층면，분별우골관절면하송질골내、린근기육화지방내선택감흥취구（면적위100mm2），측량 CT 치、평균표준차（SD）작위조성치，기록제량장도승적（dose‐length product ，DLP）。채용 Likert 5분평개주관도상질량，병통과 Kappa 방법평개관찰자간적일치성。결과량조재각상동송질골내（218．00±64．57）HU vs （219．23±54．27）HU （ P ＝0．936）、린근기육내（55．67±7．45）HU vs （53．73±4．66）HU （ P ＝0．233）、지방내（‐97．67±10．60）HU vs （‐95．30±14．62）HU （ P ＝0．476），CT 치차이균무통계학의의；도상조성화주관도상질량평분차이야무통계학의의。량조 DLP 분별위（27.20±5.51）mSv vs（78．37±18．51）mSv ，A 조교 B 조분별강저료65．3％（ P ＜0．001），차이유통계학의의。결론당사용저mAs（60mAs）연합질대중건산법진행저가관절 CT 성상시，재보지도상질량적동시，환능겁대강저유효복사제량。
Objective To investigate the impact of SAFIRE technique on image quality and radiation dose of sacroiliac joint dual‐source computed tomography .Methods 60 patients who underwent sacroiliac joint CT scan were randomly di‐vided into two groups .The patients in group A were scanned using the low tube current 60 mAs and images were recon‐structed using iterative reconstruction technique (SAFIRE ,Siemens Healthcare) .The patients in group B were scanned u‐sing the tube current 150 mAs and images were reconstructed using filtered back projection (FBP) .CT attenuation and noise was measured in the cancellous bone ,adjacent muscle and fat respectively .Subjective image quality scores and dose‐length product were compared between the two groups .Results There was no significant difference in the mean CT atten‐uation achieved ,image noise and mean image quality score in cancellous bone , adjacent muscle and fat between two groups .The DLP were (27 .20 ± 5 .51) mSv vs (78 .37 ± 18 .51) mSv for 60 mAs group and 150 mAs group respectively . Reflecting dose saving was 65 .3% ( P < 0 .001) .Conclusion The results demonstrate that with a combination of iterative reconstruction and a lower tube current (60 mAs) can keep the image quality ,as well as significantly lower DLP .