CAJ | 학술논문

目的比较256层CT前置门控冠状动脉CTA与回顾门控检查方法的成像质量及辐射剂量,探讨256层CT前置门控冠状动脉扫描方法的临床应用价值及局限性.方法回顾分析177例冠状动脉256层CTA检查患者,其中前置门控86例,回顾门控91例.将冠状动脉主要分支分为9个节段评价,采用4分法评价图像质量,≥3分为可评价节段.采用t检验比较两种方法组可评价节段的百分比、患者的有效辐射剂量及图像噪声.结果前置门控组86例中98.8%节段(765/774)为可评价节段.回顾门控组91例中99.6%节段(816/819)可评价.2组图像质量差异有统计学意义(t=2.51,P=0.01).心率<75次/min时,前置门控与回顾门控组的可评价节段分别为99.8%(647/648),99.7%(718/720),图像质量的差异无统计学意义(t=1.90,P>0.05).≥75次/min时,2组的可评价节段分别为93.6%(118/126)和99.0%(98/99).2组的可评价率差异有统计学意义(t=3.57,P<0.05).前置门控组及回顾门控组的有效辐射剂量分别为(4.4±0.5)和(10.3±1.5)mSv(t=33.4,P<0.00),前置门控扫描的剂量明显小于回顾门控扫描,下降幅度达60.0%.结论 256层CT前置门控冠状动脉扫描方法较回顾门控方法剂量显著降低,两种扫描方法得到的图像质量均较好.在低心率组图像质量两种方法相近,而高心率组前置门控较回顾门控法有差距.
목적 비교256층CT전치문공관상동맥CTA여회고문공검사방법적성상질량급복사제량,탐토256층CT전치문공관상동맥소묘방법적림상응용개치급국한성.방법 회고분석177례관상동맥256층CTA검사환자,기중전치문공86례,회고문공91례.장관상동맥주요분지분위9개절단평개,채용4분법평개도상질량,≥3분위가평개절단.채용t검험비교량충방법조가평개절단적백분비、환자적유효복사제량급도상조성.결과 전치문공조86례중98.8%절단(765/774)위가평개절단.회고문공조91례중99.6%절단(816/819)가평개.2조도상질량차이유통계학의의(t=2.51,P=0.01).심솔<75차/min시,전치문공여회고문공조적가평개절단분별위99.8%(647/648),99.7%(718/720),도상질량적차이무통계학의의(t=1.90,P>0.05).≥75차/min시,2조적가평개절단분별위93.6%(118/126)화99.0%(98/99).2조적가평개솔차이유통계학의의(t=3.57,P<0.05).전치문공조급회고문공조적유효복사제량분별위(4.4±0.5)화(10.3±1.5)mSv(t=33.4,P<0.00),전치문공소묘적제량명현소우회고문공소묘,하강폭도체60.0%.결론 256층CT전치문공관상동맥소묘방법교회고문공방법제량현저강저,량충소묘방법득도적도상질량균교호.재저심솔조도상질량량충방법상근,이고심솔조전치문공교회고문공법유차거.
Objective To retrospectively compare the image quality and radiation dose for coronary CT angiography obtained with a prospectively gated transverse (PGT) CT technique and a retrospectively gated helical (RGH) CT technique. Methods Coronary CT angiography obtained with 256-slice CT were retrospectively evaluated in 177 patients. The main branches of coronary arteries were divided into 9 segments. The image quality was evaluated with a four-point grading scale. The assessability of coronary artery segment, image quality score and radiation dose for prospective and retrospective CT angiography were compared with student t test. Results The PGT technique was used in 86 patients. The routine RGT technique was used in 91 patients. The percentage of assessable coronary artery segments was 98. 8% (765 of 774)with PGT technique versus 99. 6% (816 of 819) with RGH technique (t = 2. 51, P = 0. 01 ). In patients with heart rates under 75 beats per minute, the image quality of coronary artery branches was similar between PGT and RGH techniques (99. 8% versus 99. 7%, t = 1.90, P > 0. 05 ) . In patients with heart rates above 75 beats per minute, the image quality with RGH technique was better than that with PGT technique (99.0% versus 93. 6%, t = 3.57, P < 0. 05 ). Effective dose with prospective CT angiography was 60. 0% lower than that with retrospective CT angiography [ (4. 4 ± 0. 5 ) vs ( 10. 3 ± 1.5 ) mSv, t = 33.4,P <0. 05 ]. Conclusions Prospective CT angiography can reduce effective radiation dose obviously. The PGT technique offers the similar image quality with RGH technique in patients with heart rates under 75 beats per minute and RGH technique has better image quality in patients with heart rates above 75 beats per minute.