CAJ | 학술논문

目的探讨64层螺旋CT脑灌注间隔轴扫模式降低扫描剂量的可行性.方法临床可疑卒中患者145例,按照时间顺序分别进行连续轴扫模式(电影组)和间隔扫描模式(轴扫组)的脑灌注成像,选择两组检查结果正常者各20例.电影组采用Cine full扫描模式,扫描时间1 s,在50 s内连续曝光扫描.轴扫组使用Axial full扫描模式,扫描时间1 s,间隔时间2 s,两组扫描范围均为40 mm.测量两组双侧额叶、颞叶、枕叶的灰质、白质和基底节区脑血流量(CBF)、血容量(CBV)、平均通过时间(MTT),两组间比较采用t检验.记录两组扫描辐射剂量CT容积剂量指数(CTDIvol)和剂量长度乘积(DLP),采用百分数进行对比分析.结果电影组脑灰质、白质及豆状核CBF分别为(48.8±16.0)、(28.3±12.0)、(55.4±11.2)ml·100 g~(-1)·min~(-1),轴扫组分别为(47.6±9.6)、(23.9±6.9)、(53.1±5.1)ml·100 g~(-1)·min~(-1);电影组CBV分别为(2.2±0.7)、(1.5±0.5)、(2.3±0.8)ml/100 g,轴扫组分别为(2.2±0.6)、(1.5±0.4)、(2.2±0.7)ml/100 g;电影组MTT分别为(3.9±0.8)、(5.3±0.9)、(2.8±0.4)s,轴扫组分别为(6.0±1.7)、(6.0±1.7)、(3.0±0.3)s,两组间CBF、CBV及MTT差异均无统计学意义(t值分别为0.244、1.533、0.832、0.166、0.411、0.537、1.688、1.471、1.638,P值均＞0.05).电影组DLP为2361.92 mGy·cm,轴扫组为803.04 mGy·cm,比电影组降低66%.结论使用扫描时间1 s、间隔2 s的轴扫模式可以在保证脑灌注参数准确性的基础上降低辐射剂量.
목적 탐토64층라선CT뇌관주간격축소모식강저소묘제량적가행성.방법 림상가의졸중환자145례,안조시간순서분별진행련속축소모식(전영조)화간격소묘모식(축소조)적뇌관주성상,선택량조검사결과정상자각20례.전영조채용Cine full소묘모식,소묘시간1 s,재50 s내련속폭광소묘.축소조사용Axial full소묘모식,소묘시간1 s,간격시간2 s,량조소묘범위균위40 mm.측량량조쌍측액협、섭협、침협적회질、백질화기저절구뇌혈류량(CBF)、혈용량(CBV)、평균통과시간(MTT),량조간비교채용t검험.기록량조소묘복사제량CT용적제량지수(CTDIvol)화제량장도승적(DLP),채용백분수진행대비분석.결과 전영조뇌회질、백질급두상핵CBF분별위(48.8±16.0)、(28.3±12.0)、(55.4±11.2)ml·100 g~(-1)·min~(-1),축소조분별위(47.6±9.6)、(23.9±6.9)、(53.1±5.1)ml·100 g~(-1)·min~(-1);전영조CBV분별위(2.2±0.7)、(1.5±0.5)、(2.3±0.8)ml/100 g,축소조분별위(2.2±0.6)、(1.5±0.4)、(2.2±0.7)ml/100 g;전영조MTT분별위(3.9±0.8)、(5.3±0.9)、(2.8±0.4)s,축소조분별위(6.0±1.7)、(6.0±1.7)、(3.0±0.3)s,량조간CBF、CBV급MTT차이균무통계학의의(t치분별위0.244、1.533、0.832、0.166、0.411、0.537、1.688、1.471、1.638,P치균＞0.05).전영조DLP위2361.92 mGy·cm,축소조위803.04 mGy·cm,비전영조강저66%.결론 사용소묘시간1 s、간격2 s적축소모식가이재보증뇌관주삼수준학성적기출상강저복사제량.
Objective To investigate the feasibility of reducing X-ray dose in 64-slice CT brain perfusion by relaxing the temporal resolution with an axial scan mode.Methods Forty patients who underwent CT perfusion scans for suspicion of stroke but turned out to have normal brain perfusion were selected for the study.Among these patients,20 were scanned with cine scan mode,which meant continuous scanning for 50 s with scan time of 1 s.And other 20 patients were scanned with axial mode,which was consisted of 1 s scan time and 2 s interval between scans.The axial coverage was 40 mm for all patients.The regional cerebral blood flow (CBF),regional cerebral blood volume (CBV) and mean transit time (MTT)were analyzed by t-test for three anatomic features:the cortical gray matter(GM),the normal white matter (WM) and the lentiform nucleus(LN).The radiation dose between the two groups was compared.Results The CBF of GM,WM,LN measured with cine scan mode were (48.8±16.0),(28.3±12.0),(55.4±11.2)ml·100g~(-1)·min~(-1).The CBV were(2.2±0.7),(1.5±0.5),(2.3±0.8)ml/100g.The MTT were (3.9±0.8),(5.3±0.9),(2.8±0.4) s.The CBF of GM,WM,LN measured with axial mode were(47.6±9.6),(23.9±6.9),(53.1±5.1)ml·100g~(-1)·min~(-1).The CBV were(2.2±0.6),(1.5±0.4),(2.2±0.7) ml·100g.The MTT were (6.0±1.7),(6.0±1.7),(3.0±0.3)s.There were no statistically significant differences between the corresponding parameters for the two groups (t=0.244,1.533,0.832,0.166,0.411,0.537,1.688,1.471,1.638,P＞0.05).The radiation dose with the axial mode was803.04mGy·cm,which was 66% lower than that with cine mode (2361.92mGy·cm). Conclusion The use of relaxed temporal resolution with 1 s scan time and 2 s interval in CT brain perfusion can provide accurate pedusion parameters while reducing radiation by 66%.